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  • Int J Prev Med
  • v.4(8); 2013 Aug

Potential Health Impacts of Hard Water

Pallav sengupta.

Department of Physiology, Vidyasagar College for Women, University of Calcutta, Kolkata, West Bengal, India

In the past five decades or so evidence has been accumulating about an environmental factor, which appears to be influencing mortality, in particular, cardiovascular mortality, and this is the hardness of the drinking water. In addition, several epidemiological investigations have demonstrated the relation between risk for cardiovascular disease, growth retardation, reproductive failure, and other health problems and hardness of drinking water or its content of magnesium and calcium. In addition, the acidity of the water influences the reabsorption of calcium and magnesium in the renal tubule. Not only, calcium and magnesium, but other constituents also affect different health aspects. Thus, the present review attempts to explore the health effects of hard water and its constituents.

INTRODUCTION

Water is essential for hydration and therefore, for life. It is also very important in food preparation and cooking, sanitation and hygiene, and a wide range of other uses. The drinking water supply has a primary objective of protecting human health, including ensuring access to adequate quantities of safe water. It is estimated that approximately 17% of the world's population uses water from the unprotected and remote sources, 32% from some form of protected sources and 51% from some sort of centralized (piped) system to the dwelling or a plot. Of the latter, a small but increasing proportion applies some form of treatment within the home. Individual water consumption occurs both at home and elsewhere, such as at schools and workplaces. Drinking-water is consumed not only as water per se but also in beverages and incorporated in food-stuffs. In response to increasing global and local water scarcity, there is an increasing use of sources such as recovered/recycled water, harvested rainwater, and desalinated water. 884 million people lack access to safe water supplies; approximately one in eight people.[ 1 ] Among them a good percentage consumes hard water, which is considered to be a significant etiological factor around the globe causing many diseases such as cardiovascular problems, diabetes, reproductive failure, neural diseases, and renal dysfunction and so on.

Hard water is usually defined as water, which contains a high concentration of calcium and magnesium ions. However, hardness can be caused by several other dissolved metals; those forms divalent or multivalent cations, including aluminum, barium, strontium, iron, zinc, and manganese. Normally, monovalent ions such as sodium and potassium do not cause hardness. These divalent cations have a propensity to come together with anions in the water to form stable salts. The type of anion found in these salts distinguishes between the two types of hardness-carbonate and non-carbonate hardness [ Table 1 ].

Carbonate and non-carbonate hardness compounds

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Carbonate hardness is caused by the metals combined with a form of alkalinity. Alkalinity is the capacity of water to neutralize acids and is attributed to compounds such as carbonate, bicarbonate, hydroxide, and sometimes borate, silicate, and phosphate. In contrast, non-carbonate hardness forms when metals combine with anything other than alkalinity. Carbonate hardness is sometimes called temporary hardness because it can be removed by boiling water. Non-carbonate hardness cannot be broken down by boiling the water, so it is also known as permanent hardness. In general, it is necessary to distinguish between the two types of hardness because the removal method differs for the two. Total hardness includes both temporary and permanent hardness caused by the calcium and magnesium, on the basis of which water is categorized as soft or hard and very hard [ Table 2 ]. The ratio of calcium and magnesium in water is also a crucial factor indicating the hardness and in the causation of several hard water health problems. Hardness generally enters groundwater as the water percolates through minerals containing calcium or magnesium. The most common sources of hardness are limestone (which introduces calcium into the water) and dolomite (which introduces magnesium.) Since, hardness enters the water in this manner groundwater generally has a greater hardness than surface water.[ 2 ]

Concentrations of dissolved calcium and magnesium in soft and hard water

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POTENTIAL HEALTH EFFECTS

Hard water has no known adverse health effect, WHO says at its Geneva Conference. In addition, hard water, particularly very hard water, could provide an important supplementary contribution to total calcium and magnesium intake.[ 3 ] The health effects of hard water are mainly due to the effects of the salts dissolved in it, primarily calcium and magnesium. To a large extent, individuals are protected from excess intakes of calcium by a tightly regulated intestinal absorption mechanism through the action of 1, 25-dihydroxy-vitamin D, the hormonally active form of vitamin D. Although, calcium can interact with iron, zinc, magnesium, and phosphorus within the intestine, thereby reducing the absorption of these minerals. On the other hand, the major cause of hypermagnesemia is renal insufficiency associated with a significantly decreased ability to excrete magnesium.[ 4 ] Increased intake of magnesium salts may cause a change in bowel habits (diarrhea). Drinking-water in which both magnesium and sulfate are present in high concentrations (~250 mg/l each) can have a laxative effect. Laxative effects have also been associated with excess intake of magnesium taken in the form of supplements, but not with magnesium in the diet.

Cardiovascular disease

In most large-scale studies, an inverse relationship between the hardness of drinking-water and cardiovascular disease has been reported.[ 5 , 6 , 7 , 8 , 9 , 10 , 11 ] However, no such association has been found in some other studies,[ 12 , 13 ] particularly in those involving small geographical areas a clear association is often not found.[ 14 ] The extent to which confounding variables, such as climatic, socioeconomic, or major risk factors, may account for the inverse relationship is unclear. Nevertheless, in a number of studies, a weak inverse relationship was reported after allowance was made for climatic and socioeconomic factors[ 15 ] and after major risk factors such as hypertension, smoking habits, and elevated serum lipids were taken into account.[ 16 , 17 ] An inverse relationship between hardness and cardiovascular disease has been reported in men after allowing for climatic and certain social factors, but only up to about 170 mg of calcium carbonate/l.[ 18 ] A variety of hypotheses have been proposed to explain the possible inverse association.[ 19 , 20 , 21 , 22 , 23 , 24 ] However, none has been fully substantiated, nor has a particular element been found to be conclusively associated with the cardiovascular disease. It may be correlated with a high level of magnesium in hard water, which has some anti-stress actions against coronary heart disease. In a study of regional differences in mortality in cardiovascular diseases in 76 municipalities in mid-Sweden a considerable gradient was found between the western areas with a high mortality and soft water and the eastern areas with a low mortality and hard water. The hardness of water defined as the sum of the content of calcium and magnesium, was shown to be of considerable influence of the differences in mortality compared to major risk factors.[ 16 ] The incidence of coronary heart disease varies widely in different geographical regions over the world and serious epidemiological studies have been carried out to identify variables that could explain this fact. The role of water hardness has been widely investigated and evaluated for many years in several studies where regional differences in cardiovascular disease have been discussed.[ 16 , 25 , 26 , 27 , 28 , 29 ] Earlier studies have found positive correlations between water and dietary magnesium and calcium and blood pressure.[ 30 , 31 , 32 , 33 ] In Finland and South Africa it was found that the incidence of death ascribed to ischemic heart disease is inversely correlated with the concentration of magnesium in drinking water[ 29 ] and also in a Swedish case control study magnesium, and calcium in drinking water were associated with a lower mortality from acute myocardial infarction in women but not with the total incidence.[ 26 , 34 ] However, other studies could not confirm these findings,[ 31 , 32 ] conversely, in a study of magnesium in drinking water supplies and mortality from acute myocardial infarction in North-West England, there was likewise evidence of an association between magnesium and cardiovascular mortality.[ 25 ] In a Swedish study, the skeletal muscle magnesium levels were a significantly higher in persons living in an area with a higher water magnesium.[ 35 ] The concentration of magnesium in striated muscle has been used as a marker to evaluate the ion content in the soft tissue.

Important findings in this field were provided recently by Taiwanese scientists. In most of their studies, the authors indicated a negative statistical association of various types of cancer morbidity/mortality with the hardness of water and calcium. In a review of these publications, it is worth noting the results concerning the possible association between the risk of gastric cancer and the levels of calcium and magnesium.[ 36 ] Some studies suggest there was a significant protective effect of calcium intake from drinking water on the risk of gastric cancer. Magnesium also exerted a protective effect against gastric cancer, but only for the group with the highest levels of magnesium exposure.[ 37 ] In another matched case-control study, the authors found a possible association between the risk of colon cancer and hardness levels in drinking water from municipal supplies in Japan (obtained trend analyses showed an increasing odd ratio for the cancer with decreasing hardness in drinking water).[ 38 , 39 ] Similar epidemiological trends were also achieved for the relations between hardness levels in drinking water, and the risk of rectal cancer and pancreatic cancer mortality, however, the researchers did not find any association with magnesium levels (the adjusted odds ratios were not statistically significant for the relationship between magnesium concentrations in drinking water and rectal cancer).[ 40 ] One of the strongest epidemiological evidences of significant protective effect of magnesium intake from the drinking water was that gave for the risk for esophageal cancer and ovarian cancer.[ 41 , 42 ] Unfortunately, these authors did not find any results pertaining to the similar trend between drinking-water magnesium and liver cancer. The first strong evidence concerning the possible ecological relation between exposure to water magnesium and hepatic cancer was reported in Eastern Europe.[ 43 ]

Cerebrovascular mortality

Some reports suggest there is a significant protective effect of magnesium intake from the drinking water on the risk of cerebrovascular disease.[ 44 ] Despite their inherent limitations, studies on the ecological correlation between mortality and environmental exposures have been used widely to generate or discredit epidemiological hypotheses. Dietary calcium is the main source of calcium intake. Epidemiological studies have shown that dietary calcium is inversely associated with the blood pressure. With much of the epidemiological literature suggesting a relationship between the dietary calcium and blood pressure, it would seem reasonable to expect that intake of dietary calcium could reduce the risk of cardiovascular events, such as stroke that are commonly associated with hypertension.[ 45 ] However, controlling for magnesium levels eliminates the perceived effect of calcium levels on cerebrovascular mortality. In the general population, the major proportion of magnesium intake is through food, and a smaller proportion is through drinking water. For individuals with the borderline magnesium deficiency, waterborne magnesium can make an important contribution to their total intake. In addition, the loss of magnesium from food is lower when the food is cooked in magnesium-rich water. Magnesium in water can also play a critical role because of its high bioavailability. Magnesium in water appears as hydrated ions, which are more easily absorbed than magnesium in food. The contribution of water magnesium among persons who drink water with a high magnesium levels could be crucial in the prevention of magnesium deficiency. The significant association between mortality from the cerebrovascular disease and the levels of magnesium in drinking water is supported by knowledge of the functions of magnesium. Magnesium is an enzyme (Na + /K + ATPase) activator and regulates cellular energy metabolism, vascular tone, and the cell membrane ion transport. A lack of magnesium leads to a decrease in the concentration of intracellular potassium and an increase in calcium levels. Magnesium deficiency may increase the contractility of blood vessels. Magnesium causes vasodilation by stimulation of endothelial prostacyclin release and in vivo , prevents vasoconstriction of the intracranial vessels after experimental subarachnoid hemorrhage. In addition, fear of cerebrovascular disease should not deter anyone from drinking water with a low magnesium levels. In conclusion, the results of the present study show that there is a significant protective effect of magnesium intake from drinking water on the risk of cerebrovascular disease. This is an important finding for the Taiwan water industry and human health risk assessment.[ 46 ]

Malformations of central nervous system

There is good evidence that environmental influences must play some part, possibly a major part, in the etiology of neural tube malformations in the human embryo. Almost all that evidence, however, relates to non-specific and uncertain markers of as yet unidentified specific teratogens. For example, the frequency of malformations of the central nervous system varies greatly from country to country.[ 47 , 48 ] It also varies from area to area within countries: In the United States for the period 1950-59, mortality from spina bifida (myelomeningocele) was 2-3 times greater on the Atlantic coast than on the Pacific coast;[ 49 ] in South Wales the frequency of central nervous system malformations in the coal-mining valleys is almost twice as high as in the coastal plain;[ 50 ] in England and Wales as a whole the frequency is highest in the north, the north-west, and Wales and lowest in the East, Southeast, and South.[ 51 , 52 ] It is higher in first-born than in later born infants and in infants born to younger and older mothers than to mothers in mid-reproductive life.[ 51 , 53 ] It is higher among infants born in the poorer than in the well-to-do strata of society.[ 54 , 55 , 56 ] It tends to be higher among winter than among summer births.[ 51 , 53 , 55 , 57 , 58 , 59 ] Striking secular swings in frequency have been reported in the Birmingham, Scotland, Dublin, and Boston. 70-71 Penrose[ 48 ] seems to have been the first to speculate “the geographical variations observed in the incidence (of anencephalus) might suggest a… causal agent, such as the presence or absence of trace elements in the water supply.” This suggestion has been taken up by Fedrick.[ 60 ] She related data on anencephalus for 10 different areas in the United Kingdom (from 10 different studies and relating to 10 different time-periods) to information about the water supplies of those areas obtained from various sources. Despite such manifestly unsatisfactory data, she found that the frequency of anencephalus was a significantly related to measurements of the total hardness, calcium content, and pH of the local water supplies. Stocks[ 52 ] examined the mean annual death rates (still-births plus infant deaths) for congenital malformations in the 15 hospital regions of England and Wales. Mortality rates were highest in the north and the west and lowest in the Southeast. Having observed that mortality from cardiovascular disease followed much the same regional pattern, he proceeded to correlate death rates from congenital malformations in the 15 regions with death rates of women aged 25-54 from the certain causes in the corresponding regions. He found that mortality from malformations of the neural tube correlated very closely with mortality from the cardiovascular diseases, whereas other malformations produced insignificant negative correlations. He concluded that because mortality from cardiovascular disease in the county boroughs of England and Wales has been shown to be strongly an associated with softness of their water supplies,[ 61 ] a water factor might be responsible for the regional variations of mortality from the central nervous system malformations. In this paper, and against this background, we relate area differences in mortality from malformations of the central nervous system in South Wales to estimates of the hardness of the water supplies in these areas. We also present new data on perinatal mortality from anencephalus in the county boroughs of England and Wales and relate them to estimates of the hardness of their water supplies.

Alzheimer's disease

The issue of aluminum as a cause for Alzheimer's disease has been contentious. In special circumstances such as renal failure and massive exposure to aluminum in certain occupations aluminum may cause brain pathology similar to Alzheimer Disease. However, there is no definite evidence of the role of this metal in the causation or development of Alzheimer disease. In a survey of 88 county districts within England and Wales, rates of Alzheimer's disease in people under the age of 70 years were estimated from the records of the computerized tomographic (CT) scanning units that served these districts. Rates were adjusted to compensate for differences in the distance from the nearest CT scanning unit and for differences in the size of the population served by the units. Aluminum concentrations in water over the past 10 years were obtained from water authorities and water companies. The risk of Alzheimer's disease was 1.5 times higher in districts where the mean aluminum concentration exceeded 0.11 mg/l than in districts where concentrations were less than 0.01 mg/l.[ 62 ]

Hard water is indicative of the presence of higher levels of magnesium. In certain areas, drinking water actually contains 100% or more of the recommended daily allowance about magnesium, which is around 300-400 mg daily with levels varying according to gender and age. Because, all kinases and other ATP-related enzymes and channels regulating insulin action are dependent on magnesium, it is not surprising that serum magnesium concentrations have been found to be decreased in non-diabetic subjects with metabolic syndrome and that hypomagnesaemia is a common feature in subjects with type-2 diabetes. Whether the low intracellular magnesium content is secondary to or precedes insulin resistance is unclear; however, recent evidence suggests that sub-clinical magnesium deficiency may precipitate a diabetic state. Studies are needed to determine the role of sub-clinical magnesium status in diabetes risk. This should include measures of glycosylated hemoglobin, an indicator of glycemic control that has been found to respond to oral magnesium supplementation and to correlate negatively with serum ionized magnesium or serum total magnesium in type 2 diabetics.[ 63 ]

Childhood atopic dermatitis

Atopic dermatitis (or eczema) is an inflammatory, chronically relapsing, non-contagious and pruritic skin disorder. The environment plays an important part in the etiology of atopic eczema, but the specific causes are unknown. Exposure to hard water is thought to be a risk factor for eczema. The prevalence of symptoms of atopic eczema among Japanese, Nottinghamshire and Spanish children is the most. The reasons for such a high prevalence are unknown. The study used data on water hardness and chlorine content of the water supply; prevalence of atopic dermatitis diagnosed by physicians and episodes of wheezing reported by the parents; and potential confounding factors by socioeconomic and health-care status per municipality. The prevalence of atopic eczema was significantly higher in the highest water hardness category than that in the lowest respectively. A significant relationship between the chlorine content of the water supply and the prevalence of atopic dermatitis was observed after adjustment for confounding factors. Water hardness may increase the risk of atopic dermatitis among elementary-school children in Japan, as well as in the United Kingdom.[ 64 ]

Kidney stones

The hardness of water is due to the presence of carbonate and sulfate salts of calcium and magnesium. More than 3/4 th of kidney stones are generally composed of calcium salt and usually occur as calcium oxalate and less commonly as calcium phosphate. The remaining 20% of stones are composed of uric acid, struvite and cystine stone. Stones form in urine that is supersaturated and this saturation is dependent on chemical free ion activity, which makes the urine under-saturated. In this situation, the stone will not grow and may even dissolve. Increased urinary ion excretion and decreased urine volume will both an increase free ion activity and favor stone formation and growth. Formation of kidney stones (nephrolithiasis) is based on genetic, metabolic, nutritional and environmental factors. Metabolic factors involved in stone formation include hypercalciuria, hypocitraturia (due to renal disease), hyperuricosuria, hyperoxalaturia, cystinuria and infections. Environmental and nutritional factors include dehydration, high salt intake, a diet rich in animal proteins and calcium rich diet when oxalate intake is restricted. The impact of water hardness of urinary stone formation remains unclear, despite a weak correlation between water hardness and urinary calcium, magnesium, and citrate excretion. Several studies have shown no association between water hardness and the incidence of urinary stone formation. A correlation between water hardness and urinary calcium, citrate, and magnesium levels has been observed although the significance of this is not known. Some studies suggest that in the preventive approach to calcium nephrolithiasis, intake of soft water has been preferable to hard water since it is associated with a lower risk for recurrence of calcium stones.[ 65 ]

Reproductive health

There are few reports of the effect of water hardness over reproductive health of men, most of them emphasized on the effect of its constituents, calcium, and magnesium,[ 66 ] while others on some other constituents like fluoride.[ 67 ] However, some reports show the occurrence of reproductive failure and stillbirth in India in hard water regions of India.[ 68 , 69 ] Some of these are showing the effect of excess calcium on the reproductive system and its negative influence on fertility.[ 68 , 70 , 71 ] These reports demonstrated the oxidative stress induced infertility in men by calcium,[ 72 ] but showed beneficial effects of magnesium.[ 4 ] There are also some reports of effects of waterborne fluoride on growth, reproduction and survival which showed long-term exposure of fluoride causes a progressive decline in reproduction.[ 67 ] On the contrary, in female, magnesium sulfate present in hard water is indicated to prevent eclampsia in patients with pre-eclampsia. Magnesium sulfate decreases the risk of developing eclampsia around 50% and also decreases maternal mortality.[ 73 ] The WHO considers that magnesium sulfate is the elective drug for the prevention of eclampsia in patients suffering from pre-eclampsia. Magnesium sulfate has also been demonstrated to prevent preterm labor.[ 74 ]

Digestive health and constipation

Even GI health is also reported being benefited from hard water since it provides potentially alleviating effects on the onset of constipation in the 85% cases. A rich union of calcium and magnesium in hard water, in a right combination, helps to combat constipation. The calcium in hard water results in teaming up with excess bile and its resident fats to lather up the soap like insoluble substance, which is emitted from the body during bowel movements. Indeed, many renowned scientists have considered hard water as a boon as it has some fantastic health benefits that seem to encourage longer life expectancy and improved health. Magnesium salt represents with a laxative effect. This provides a rapid evacuation of intestine. Magnesium citrate, magnesium phosphate, and magnesium hydroxide are also used. The American Gastroenterology Association recommends milk of magnesia for the management of constipation as one of the therapeutic options; however, the Rehabilitation Nursing Foundation discourages the routine use of saline magnesium laxatives due to possible side effects such as abdominal cramping, watery stools, and potential for dehydration and hypermagnesium. They only indicate the use of these laxatives in end-stage patients when other options have failed, and with and adequate prospective evaluation of magnesium levels.

Bone mineral density

The correlation between calcium and magnesium in drinking water and its impact on bone health are unidentified. There is some evidence that high-calcium water is beneficial to bone.[ 75 ] It has been reported in a study that spine mineral density was significantly higher in women aged 30-70 years living in Sangemini, a region of central Italy, who drank the local high-calcium water (318 mg/l), compared with women in the same region who drank low calcium water (<60 mg/l). The estimated difference in calcium intake from an assessment of diet and water was 258 mg/day on average.[ 76 ] In an evaluation of calcium ingested from water and hip bone mineral density in French women aged 75 years or older, an increase in calcium of 100 mg/day from drinking-water was found to be associated with a 0.5% increase in femoral bone density).[ 77 ]

Other health effects

The results of several studies have suggested that a variety of other diseases are also inversely correlated with the hardness of water, including anencephaly[ 78 , 79 ] and various types of cancer.[ 80 , 81 , 82 , 83 , 84 , 85 , 86 ] However, the significance of these results is unclear, and it has been suggested that the associations may reflect disease patterns that can be explained by social, climatological, and environmental factors, rather than by the hardness of the water.

CONCLUSIONS

Hardness is important for drinking-water from the point of view of both aesthetic acceptability and operational considerations. Although, there is some evidence from epidemiological studies for a protective effect of magnesium or hardness on cardiovascular mortality, the evidence is being debated and does not prove causality. Further studies are being conducted. In spite of this, drinking-water may be a source of calcium and magnesium in the diet and could be important for those who are marginal for calcium and magnesium intake. Where drinking-water supplies are supplemented with or replaced by dematerialized water that requires conditioning, consideration should be given to adding calcium and magnesium salts to achieve concentrations similar to those that the population received from the original supply. Consumers should be informed of the mineral composition of their water when it has been altered by piped suppliers or treatment device manufacturers and by means for supplementing if desired. The contribution of drinking-water minerals for mineral nutrition should be considered where changes in supply are proposed or where novel sources, such as seawater or brackish water, are exploited for drinking-water. There are insufficient data to suggest either minimum or maximum concentrations of minerals at this time, and so no guideline values are proposed.

Source of Support: Nil

Conflict of Interest: None declared

A Study On Effects Of Hard Water On Human Health

Research Ambition: An International Multidisciplinary e-Journal , vol. 6 , núm. IV , pp. 15-16 , 2022

Welfare Universe

water hardness research paper

Recepción: 10 Febrero 2022

Aprobación: 18 Febrero 2022

DOI: https://doi.org/10.53724/ambition/v6n4.06Received10thFeb.2022

Abstract: Water, a universal solvent is transparent, colourless, odourless and tasteless chemical substance. Water is essential for hydration hence needed for survival of life. According to the Bureau of Indian Standard, water having the value of total dissolved solid greater than 500 ppm may be moderately hard or hard and this water can affect the human health on continuous consumption for a long time. Quality and quantitative frameworks of physicochemical and biological components of drinking water are required to regularly pay attention the quality of water from different sources of supply. This paper aims to explore

Keywords: Water, hard water, human health, save water, re-cycle water.

Introduction

In a water molecule two hydrogen atoms are bonded covalently with an atom of oxygen by sharing of electrons between atoms. Water is an excellent solvent used by living things because many biochemical reactions are taken place only in aqueous solutions. Water can dissolve many different types of substances because of its ability to form hydrogen bond and its polar nature. Rain water and treated water is soft water which contains low concentration of calcium and magnesium ions and produces lather easily with soap. Hardness is the physico-chemical property of water which prevents lather formation with soap due to presence of high mineral contents. Hard water is formed when water percolates through deposits of calcium and magnesium minerals such as sea water, river water and tap water. Hardness of water is classified into two types, carbonate and non-carbonate hardness. Carbonate hardness also called temporary hardness is due to the presence of bicarbonate and carbonate salts of calcium and magnesium. It can be removed by boiling water. Non-carbonate hardness also known as permanent hardness is due to the presence of calcium chloride, magnesium chlorides and magnesium sulphate.

Scientific studies reported that the minerals present in hard water react with soaps to form a scum like substance that can clog pores and the result may be dry skin, eczema, dandruff, damaged hair. Kobayashi, a Japanese chemist, was first to describe the relation between water hardness and the incidence of vascular disease. [ 1 ]

Sources of Hard Water

We know that what are the sources of drinking water in India such as wells, hand pumps, bore wells and tube wells and surface water sources like rivers and lakes. Hard water is caused by the presence of high amount of dissolved minerals and impurities picked up by it when it travels through the ground. When water moves continuously through soil and rocks on our earth, it gets contaminated by the absorption of high mineral contents and becomes hard water. Calcium and magnesium salts, dissolved other metal salts, bicarbonates, silicates and sulphates are governing causes of hardness of water. Hard water is defined as water that contains soluble salts of calcium and magnesium as Bicarbonates, Chlorides and Sulphates. Types of water hardness Water hardness is of two types: temporary hardness and permanent hardness. Temporary stiffness is caused by the soluble calcium and magnesium salts present in the water as bicarbonates. This type of hardness, also called carbonate hardness can be removed by boiling the water. Boiling the water assists the reaction liberating carbon dioxide which drives off and the carbonate ion reacts with Ca2+ or Mg2+ ions to form insoluble calcium and magnesium carbonates which filter out and available water is become soft.

water hardness research paper

Persistent hardening is due to the presence of soluble chlorides and calcium, magnesium and Sulphates in the water and these can’t be removed by boiling water. There are several ways to remove permanent stiffness in water, such as Calgon method, ion exchange method, soda bath method etc.

Effects of hard water on health

The hardness of water is harmful to the boilers and hot water pipes as the deposition of salts occur, which can reduce their efficiency. The hard water is not good for washing as it is difficult for hard water to form lather with soap. The World Health Organisation states that hard water has no known adverse health effects. [ 2 ] There is no serious health effects associated with drinking hard water. However solid water acts as a dietary supplement as it contains calcium and magnesium that strengthens bones and teeth. [ 3 ] Hard water contains high concentration of dissolved minerals therefore millions of people think that these dissolved minerals have positive effects on the health of its drinkers. Many studies suggested that calcium and magnesium present in hard water may act as protective factors against cardiovascular diseases. [ 4 ] Consumption of hard water can give to dry skin and hair. [ 5 ] Studies have been conducted on health effects of hard water. It has been reported that drinking hard water might link to the formation of conditions of certain diseases. Hard water can change the pH balance of the skin leaving our skin less healthy than before. Hence people with skin disease may find their disease condition increasing when they wash with hard water. The pH ranges from 0 to 14 indicates how acidic or alkaline the substance is. Acidic water has pH less than 7 and alkaline water has pH greater than 7 and neutral pure water has 7 pH value. The pH balance of skin can be changed due to use of hard water, which decrease the protective strength of skin against bacteria and infections. The skin problems are caused by the presence of excessive minerals in the water. About 80 percent of disease in developing countries is caused by consuming contaminated water, yet many of the households across the country do not treat their drinking water. The Bureau of Indian Standard (BIS) has developed a guide for safe drinking water.[ 6 ] According to the Central Ground Water Board, the BIS have protocol specifications for monitoring the level of drinking water as figure[ 7 ] no. 2. Several studies reported that sore throats and kidney problems have been observed due to the regular consumption of hard water for a very long time.[ 8 & 9 ] The World Health Organization confirms the harmful effects of the constant use of hard water on the cardiovascular system. The human body gets calcium and magnesium from organic compounds of food but hard water contains inorganic compounds of these elements, and hence they are absorbed unacceptable. As a result, accumulation of excess salts in the joints may happen and thus problems of the musculoskeletal system. [ 10 ] Dangerous bacterial growth in drinking water carrying pipes due to hard water scale deposits is very harmful for human health because the scale deposits have an uneven, rough surface which are a perfect hiding place for bacteria to nest in. Excess calcium present in hard water may cause kidneys work harder to filter, stomach upset, nausea and constipation. Hypercalcemia may interfere functions of brain and heart.

Water pollution is an important environmental issue that can be due to many contaminants. Consumption of the polluted water may affect the human health. Although compounds of calcium and magnesium present in hard water are very important elements for the functioning of all living organisms, their excess and inorganic origin have harmful effect on living commodity. Various initiatives have been undertaken by government and non-government bodies to solve water crisis around the country.

References:

1. P.Ramya et al, A Study On The Estimation Of Hardness In Ground Water Samples By Edta Tritrimetric Method. International Journal of Recent Scientific Research Vol. 6, Issue, 6, pp.4505-4507, June, 2015

2. Sana Akram, Hardness in drinking water, its sources, its effects on humans and its Household Treatment, June 2018, https://www.researchgate.net/publication/325781174 , Last seen 15th Jan and-soft-water#hard-water-risks (log on 05th Jan 2022

3. Pallav Sengupta, Potential Health Impacts of Hard Water, Int J Prev Med. 2013

4. Aug; 4(8): 866–875. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3775162/4.Ibid.5

5. James Roland: Hard Water vs. Soft Water: Which One Is Healthier?: Posted on the website July 30, 2019, https://www.healthline.com/health/hard-water

6. Safe Drinking Water Guidelines in India: Posted 13th Dec. 2019, https://www.kent.co.in/blog/safe-drinking-water-guidelines-in-india / Last seen 05th Jan 2022.

7. R. P. Dahiya: Researchgate: Posted August 2006, https://www.researchgate.net/figure/Drinking-water-quality-standards-as - recommended by-BIS-and-WHO_tbl4_6888743, Last seen 06th Jan 2022.

8. Possible Effects of Using Hard Water on Human Body: Posted 17th July 2017, https://www.kent.co.in/blog/possible-effects-of-using-hard-water-on - human-body/ Last seen 05th Jan 2022.

9. Influence of hard water on the human body: Posted 15th April 2021: https://aquahomegroup.com/blogs/news/influence-of-hard-water-on human-body, Last Seen 06th Jan 2022

10.Scale And Rust Problems: https://www.cwt-india.com/hard-water - problems/ Last seen 8th Jan 2022.

Water hardness scale

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Preparation and application of bio-adsorbent for the removal of water hardness: conversion of a waste to a value-added material

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  • Published: 24 July 2021
  • Volume 13 , pages 8161–8171, ( 2023 )

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water hardness research paper

  • Chanjot Kaur 1 ,
  • Tanmoy Roy 2 ,
  • Suvadra Das 3 ,
  • Richa Gupta 2 &
  • Tanay Pramanik   ORCID: orcid.org/0000-0003-0380-7881 3  

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Biomass (a renewable resource) is getting huge attention as a feedstock for preparation of adsorbents due to its low cost of production, enormous availability and eco-friendliness. In this context, bio-adsorbent and activated carbons were synthesised using pine nut cover, amla bark, ginger peels as raw material, and their applicability in softening of hardwater was investigated. In addition, conventional and microwave method were employed to find the efficient and promising technique for their preparation. Phosphoric acid (H 3 PO 4 ) was used as a chemical activating agent because of its low toxicity and to achieve high porosity. The maximum adsorptive capacities of pine nut B, pine nut AC, Ginger AC, Amla C and Amla AC 1 were 92.92, 102.92, 88.33, 62.9 and 68.33 mg/g, respectively. The adsorbents were characterised using PXRD, SEM and FT-IR data and possible mechanism of interaction was investigated using FT-IR. Comparative analysis of adsorptive capacities and kinetics of the adsorbents revealed that pine nut covers were cost-effective and efficient material for removal of water hardness. In this study, economic, efficient and eco-friendly activated carbons have been synthesised using negative market materials for the removal of hardness from water.

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water hardness research paper

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Trends and Scope of Utilization of Biochar in Wastewater Treatment

Sustainable conversion of agro-wastes into useful adsorbents.

Fry Al, R Martin (2005) Water facts and trends. World Business Council for Sustainable Development 16.

Khayet M (2016) Fouling and scaling in desalination. Desalination 100:1

Article   Google Scholar  

Jeldres RI, Arancibia-Bravo MP, Reyes A, Aguirre CE, Cortes L, Cisternas LA (2017) The impact of seawater with calcium and magnesium removal for the flotation of copper-molybdenum sulphide ores. Miner Eng 109:10–13

Demadis KD, Mavredaki E, Stathoulopoulou A, Neofotistou E, Mantzaridis C (2007) Industrial water systems: problems, challenges and solutions for the process industries. Desalination 213:38–46

Teir S, Eloneva S, Zevenhoven R (2005) Production of precipitated calcium carbonate from calcium silicates and carbon dioxide. Energy Convers Manage 46:2954–2979

Macadam J, Parsons SA (2004) Calcium carbonate scale control, effect of material and inhibitors. Water Sci Technol 49:153–159

Kaur T, Bhardwaj R, Arora S (2017) Assessment of groundwater quality for drinking and irrigation purposes using hydrochemical studies in Malwa region, southwestern part of Punjab, India. Appl Water Sci 7:3301–3316

Glueckstern P, Priel M (2003). Upgrading of old brackish water reverse osmosis (BWRO) desalination plants. In Proceedings of 6th Annual Conference of the Israel Desalination Society (p. 59).

Van Hoek C, Kaakinen JW, Haugseth LA (1976) Ion exchange pretreatment using desalting plant concentrate for regeneration. Desalination 19:471–479

Gilron J, Daltrophe N, Waissman M, Oren Y (2005) Comparison between compact accelerated precipitation softening (CAPS) and conventional pretreatment in operation of brackish water reverse osmosis (BWRO). Ind Eng Chem Res 44:5465–5471

Reddy MM, Nancollas GH (1973) Calcite crystal growth inhibition by phosphonates. Desalination 12:61–73

Rinat J, Korin E, Soifer L, Bettelheim A (2005) Electrocrystallization of calcium carbonate on carbon-based electrodes. J Electroanal Chem 575:195–202

Westin KJ, Rasmuson ÅC (2005) Crystal growth of aragonite and calcite in presence of citric acid, DTPA, EDTA and pyromellitic acid. J Colloid Interface Sci 282:359–369

Setyono D, Valiyaveettil S (2016) Functionalized paper—A readily accessible adsorbent for removal of dissolved heavy metal salts and nanoparticles from water. J Hazard Mater 302:120–128

Fu F, Wang Q (2011) Removal of heavy metal ions from wastewaters: a review. J Environ Manage 92:407–418

Fu F, Wang Q (2011) Removal of heavy metal ions from wastewaters: a review. J Environ Manage 92(407–418):1

Google Scholar  

Abubacker, ATN (2011). Ginger: A rhizome with high export value. Market Survey (Facts for You) pp, 23–24.

Zou, Huijing, Qin Jiang, Ruilin Zhu, Yongdong Chen, Tong Sun, Mingxing Li, Jun Zhai et al. (2020). Enhanced hydrolysis of lignocellulose in corn cob by using food waste pretreatment to improve anaerobic digestion performance. Journal of environmental management 254: 109830.

Li Y, Zhang X, Yang R, Li G, Hu C (2015). The role of H 3 PO 4 in the preparation of activated carbon from NaOH-treated rice husk residue.

Liu H, Zhang J, Jiang L, Kang Y, Cheng C, Guo Z, Zhang C (2015) Development of carbon adsorbents with high surface acidic and basic group contents from phosphoric acid activation of xylitol. RSC Adv 5:81220–81228

Clougherty L, Sousa J, Wyman G (1957) C= N stretching frequency in infrared spectra of aromatic azomethines. J Org Chem 22:462–462

Kaushik R, Samal PK, Halder A (2019) Degradation of fluoroquinolone-based pollutants and bacterial inactivation by visible-light-active aluminum-doped TiO2 nanoflakes. ACS Applied Nano Materials 2:7898–7909

Mandal BK, Suzuki KT (2002) Arsenic round the world: a review. Talanta 58(1):201–235

Chen L, Zhang Y, Lin C, Yang W, Meng Y, Guo Y, Xiao D (2014) Hierarchically porous nitrogen-rich carbon derived from wheat straw as an ultra-high-rate anode for lithium ion batteries. Journal of Materials Chemistry A 2:9684–9690

Al-Ghouti, MA, Razavi MM (2020). Water reuse: Brackish water desalination using Prosopis juliflora. Environmental Technology & Innovation 17:100614.

Bendaoud-Boulahlib Y, Ghizellaoui S (2017) Study of inhibiting effect of orange peel on hard growth water. Journal of materials and Environmental Sciences 8:1076–1081

Dayanand C, Bhikshamaiah G, Tyagaraju VJ, Salagram M, Murthy AK (1996) Structural investigations of phosphate glasses: a detailed infrared study of the x (PbO)-(1–x) P2O5 vitreous system. J Mater Sci 31:1945–1967

Johns A, Qian J, Carolan ME, Shaikh N, Peroutka A, Seeger A, Cwiertny DM (2020) Functionalized electrospun polymer nanofibers for treatment of water contaminated with uranium. Environ Sci: Water Res Technol 6:622–634

Zhao R, Wang Y, Li X, Sun B, Li Y, Ji H, Wang C (2016) Surface activated hydrothermal carbon-coated electrospun PAN fiber membrane with enhanced adsorption properties for herbicide. ACS Sustainable Chemistry & Engineering 4:2584–2592

Diem M (2015) Modern vibrational spectroscopy and micro-spectroscopy: theory, instrumentation and biomedical applications. John Wiley & Sons

Book   Google Scholar  

Sharma, P. Synthesis and Characterization of Adducts of Copper II Nickel II and Oxovanadium IV Thioxanthates with Donor Molecules.

Lindoy LF (1969) Reactions involving metal complexes of sulphur ligands. Coord Chem Rev 4:41–71

Aoopngan C, Nonkumwong J, Phumying S et al (2019) Amine-functionalized and hydroxyl-functionalized magnesium ferrite nanoparticles for Congo red adsorption. ACS Applied Nano Materials 2:5329–5341

World Health Organization (WHO) (2004) Back ground document or development of WHO Guidelines for drinking-water quality. Fax 41:791

Liu J, Wong LM, Wong LH et al (2016) Immobilization of dye pollutants on iron hydroxide coated substrates: kinetics, efficiency and the adsorption mechanism. Journal of Materials Chemistry A 4:13280–13288

Water S, World Health Organization. (2006). Guidelines for drinking-water quality [electronic resource]: incorporating first addendum. Vol. 1, Recommendations.

Xie R, Jin Y, Chen Y, Jiang W (2017) The importance of surface functional groups in the adsorption of copper onto walnut shell derived activated carbon. Water Sci Technol 76:3022–3034

Lutz M, Álvarez K, Loewe V (2017) Chemical composition of pine nut (Pinus pinea L.) grown in three geographical macrozones in Chile. CyTA-Journal of Food 15:284–290

Jain PK, Das DEBAJYOTI, Pandey NALINI, Jain PRACHI (2016) Traditional Indian herb Emblica officinalis and its medicinal importance. Innov J Ayurvedic Sci 4:1–15

Mao QQ, Xu XY, Cao SY, Gan RY, Corke H, Li HB (2019) Bioactive compounds and bioactivities of ginger (Zingiber officinale Roscoe). Foods 8:185

Vermerris W, Nicholson R (2008). Biosynthesis of phenolic compounds. In Phenolic Compound Biochemistry (pp. 63–149). Springer, Dordrecht.

Johns A, Qian J, Carolan ME, Shaikh N et al (2020) Functionalized electrospun polymer nanofibers for treatment of water contaminated with uranium. Environ Sci: Water Res Technol 6:622–634

Zazoua A, Khedimallah N, Jaffrezic-Renault N (2018) Electrochemical determination of cadmium, lead, and nickel using a polyphenol–polyvinyl chloride—boron-doped diamond electrode. Anal Lett 51:336–347

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School of Basic Sciences, Indian Institute of Technology Mandi, Mandi, Himachal Pradesh, 175005, India

Chanjot Kaur

Department of Chemistry, School of Chemical Engineering and Physical Science, Faculty of Technology and Sciences, Lovely Professional University, P.O.Box 144411, Phagwara, India

Tanmoy Roy & Richa Gupta

Department of Chemistry, University of Engineering and Management, University Area, Action Area III, B/5, Newtown, Kolkata, 700160, India

Suvadra Das & Tanay Pramanik

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Kaur, C., Roy, T., Das, S. et al. Preparation and application of bio-adsorbent for the removal of water hardness: conversion of a waste to a value-added material. Biomass Conv. Bioref. 13 , 8161–8171 (2023). https://doi.org/10.1007/s13399-021-01806-1

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Received : 21 April 2021

Revised : 05 July 2021

Accepted : 19 July 2021

Published : 24 July 2021

Issue Date : June 2023

DOI : https://doi.org/10.1007/s13399-021-01806-1

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  1. (PDF) Understanding Water Hardness

    Abstract. Water hardness is important to fish culture and is a commonly reported aspect of water quality. It is a measure of the quantity of divalent ions (for this discussion, salts with two ...

  2. (PDF) Hardness of water

    If a test for hard water is measured in parts per. million or milligrams per liter you can take the total. hardness level and divid e it by 17.1 to get hardness in. grains per gallon. For example ...

  3. PDF Hardness in Drinking-water

    HARDNESS IN DRINKING-WATER 2 Estimated daily intakes of magnesium from water of about 2.3 mg and 52.1 mg in soft-water and hard-water areas, respectively, have been reported, based on adults drinking 2 litres of water per day (Neri et al., 1985). 2.2 Food Food is the principal dietary source of intake of both calcium and magnesium. Dairy

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    IJNRD2310125 International Journal of Novel Research and Development (www.ijnrd.org) b224 Abstract — Water hardness is a frequent problem that affects the quality and usage of many different water sources. The detection and elimination of hardness in water samples are summarised in this ... proposed the paper titled"Assessment of Water ...

  5. Potential Health Impacts of Hard Water

    POTENTIAL HEALTH EFFECTS. Hard water has no known adverse health effect, WHO says at its Geneva Conference. In addition, hard water, particularly very hard water, could provide an important supplementary contribution to total calcium and magnesium intake. [ 3] The health effects of hard water are mainly due to the effects of the salts dissolved ...

  6. Water Hardness and Health Effects

    A number of attempts have been made to classify water hardness. Water with hardness values greater than 150 mg L −1 is designated as very hard. Soft water has values of less than 60 mg L −1.Groundwaters in contact with limestone or gypsum (CaSO 4.2H 2 O) rocks can commonly attain levels of 200-300 mg L −1.In water from gypsiferous formations, 1,000 mg L −1 or more of total hardness ...

  7. (PDF) Potential Health Impacts of Hard Water

    Based on pre- and post-treatment water analysis, it was determined that the filtration assembly was quite effective at reducing pH, turbidity, dissolved and suspended solids, hardness, and heavy ...

  8. Water Hardness

    Aquatic Facilities. Helen E. Diggs, John M. Parker, in Planning and Designing Research Animal Facilities, 2009 2 Hardness and pH. Water hardness is defined as the measured content of divalent metal cations. Dissolved calcium (Ca ++) and magnesium (Mg ++) are the only two divalent cations found at appreciable levels in most waters.In natural water, both calcium and magnesium primarily exist ...

  9. [PDF] Understanding water hardness

    Hardness is traditionally measured by chemical titration. The hardness of a water sample is reported in milligrams per liter (same as parts per million, ppm) as calcium carbonate (mg/l CaCO3). Calcium carbonate hardness is a general term that indicates the total quantity of divalent salts present and does not specifically identify whether calcium, magnesium and/or some other divalent salt is ...

  10. Water Hardness and Health

    Water hardness is generated by a variety of polyvalent metallic ions, predominantly calcium and magnesium from sedimentary rocks, seepage, and surface runoff from the soil. Hence, it depends upon the geographical condition together with the type of water source. It is an important parameter for water users in terms of health effects.

  11. Water

    According to the Water Quality Association (WQA) and the United States Geological Survey (USGS), hard water is classified based on the Ca2+ and Mg2+ ion concentration in waters, as follows: 0-60 ppm as soft; 61-120 ppm as moderately hard; 121-180 ppm as hard and more than 180 ppm as very hard water. ... Feature papers represent the most ...

  12. Removal of hardness using natural and synthetic water ...

    Hardness in drinking water is undesirable, and hardness can be removed by different methods, such as the lime-soda process, reverse osmosis, ion exchange method, distillation, etc. ... By studying various research papers on development of water filter based on material adsorption process and also studying various papers on sand filters we found ...

  13. Water Hardness

    The hardness of water is defined as total parts per million (ppm) of CaCO 3 by weight. For example, the hardness of water 10 ppm means 10 g of CaCO 3 in one million grams of water or 0.01 g of CaCO 3 in 1-L water. Total calcium concentration in water or milk can be determined by titration with ethylene diamine tetraacetic acid (EDTA), a calcium ...

  14. PDF A Study on The Estimation of Hardness In Ground Water Samples Byedta

    But water with very high degrees of hardness is harmful to health. 120 samples of ground water samples were collected from one town and two different villages. Hardness of water can be determined by EDTA tritrimetric method. Out of all the samples tested 39 (32.5%) samples were moderately hard, 76 (63.33%) samples were hard water and 5 (4.16% ...

  15. PDF Paros water quality: a literature review of water hardness and human health

    This report provides an overview of basic information and research on the health effects of hard water, as deemed relevant to the conditions in Paros. 3.1 Kidney Stones The water hardness levels in Paros are subject to rumours linking drinking water and kidney stone formation. In this section we present the main research facts related to this ...

  16. The Effect of Water Hardness on Surfactant Deposition after Washing and

    The softened water was prepared by running the hard water through an ion-exchange water softener (Harvey's Drinking Water Filter by Harvey Water Softeners, Surrey, UK and installed at the source), which brought calcium carbonate (total hardness), calcium, and magnesium levels down from 403.5, 113.1, and 28.3 mg/L to 1.0, <0.1, and <0.05 mg/L ...

  17. Investigations on the Influence of Total Water Hardness and pH Value on

    In the framework of the ongoing EMPIR Joint Research Project (JRP) 17IND13 Metrology for real-world domestic water metering (Metrowamet), a main task is to investigate the influence of realistic operation conditions, that is, typical water qualities (suspended particles, degree of hardness, and pH value), on the measurement accuracy. For this purpose, two representative types of cold water ...

  18. PDF A Study On Effects Of Hard Water On Human Health

    Consumption of hard water can give to dry skin and hair.[5] Studies have been conducted on health effects of hard water. It has been reported that drinking hard water might link to the formation of conditions of certain diseases. Hard water can change the pH balance of the skin leaving our skin less healthy than before.

  19. A Study On Effects Of Hard Water On Human Health

    This paper aims to explore. Keywords: Water, hard water, human health, save water, re-cycle water. Introduction. In a water molecule two hydrogen atoms are bonded covalently with an atom of oxygen by sharing of electrons between atoms. ... International Journal of Recent Scientific Research Vol. 6, Issue, 6, pp.4505-4507, June, 2015. 2.

  20. (PDF) Hardness in Drinking-Water, its Sources, its Effects on Humans

    Water hardness affected powdered detergents, and, depending on the detergent type, 10-15% to > 30% extra detergent was needed to obtain a result similar to that of soft water. View Show abstract

  21. A Study On Effects Of Hard Water On Human Health

    Hard water is formed due to the presence of chlorides, sulphates and bicarbonates of calcium and magnesium in dissolved form in water or when water (such as river water, sea water and tap water ...

  22. Preparation and application of bio-adsorbent for the removal of water

    2.1 Material used. Phosphoric acid (H 3 PO 4), sodium hydroxide (NaOH) and sodium bicarbonate (Na 2 CO 3) were purchased from Rankem Glasswares and Chemicals, Pvt. Ltd. India.High purity CaCO 3 was purchased from HiMedia laboratories. Distilled water was used throughout the experiments wherever required. 2.2 Preparation of bio-adsorbents. The amla bark, pine nut cover and ginger peels used in ...

  23. (PDF) Removal of Hardness from Water Samples by a ...

    The hardness of the different water samples was reduced by 40-85% by a carbonation process with a closed pressure reactor for a 5 min reaction time. Major cations and associated anions in water ...

  24. Coatings

    The descaling roller is a significant component in steel rolling production. Under harsh service conditions, the descaling roller is subjected to the dynamic impact caused by high-pressure water erosion and a high-temperature billet descaling process for a long time. Under the harsh conditions of high temperature, strong wear, multi-cycle heat, force, flow, and multi-field strong coupling, the ...