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Water pollution and the use of alum in Pakistan
FRESH water is fundamental to the survival of humans and most other land-based life forms. However, growing population, increased economic activity and industrialization have resulted in an increased demand for fresh water. Meanwhile, rapid urbanization is changing patterns of consumption. This has resulted in severe misuse of water resources.
Discharging untreated sewage and chemical wastes directly into rivers, lakes and drains has become a habit in our country. Water bodies can no longer cope with the increasing pollution load.
In Pakistan, water is used mainly for industrial, agricultural and domestic purposes. The Punjab province draws its major share of drinking water from the natural ground water aquifer. Groundwater becomes contaminated when chemicals from surface water seep into soil and come in contact with the groundwater. According to WHO, groundwater of Lahore up to 700-ft deep has been seriously contaminated and should not be used for human consumption. In 1989, pollution was found only to a depth of 300-ft. Municipal sewage is a major source of pollution. About two million wet tons of human excreta come annually from the urban sector, of which around 50 per cent go into water bodies. National Conservation Strategy (NCS) states that almost 40 per cent of deaths are related to water borne diseases.
Domestic wastewater collects on the streets and in low-lying areas. The situation is further aggravated by the addition of untreated wastes from small-scale industries. Industrial wastewater contains toxic chemicals. It is alarming that most industries start without proper planning or waste treatment plants. Automobile service stations are another major contributor to surface water pollution. Untreated oil, grease and dirt find their way into nearby canals and rivers, where it damages the ecosystem.
The WHO reports that 25-30 per cent of all hospital admissions are connected to water borne bacterial and parasitic conditions, with 60 per cent of infant deaths associated with the same. The long-term effects on human health of pesticides and other pollutants present in water include colon and bladder cancer, miscarriage, birth defects, deformation of bones, and sterility.
Radionuclides result from mining, testing, disposal and manufacturing of radioactive material, and transportation accidents. Radionuclide contamination of fresh water has led to increased incidences of cancers, developmental abnormalities and death. Cesspools of stagnant dirty water, both in rural and urban areas, account for a large number of deaths caused by potentially fatal diseases like cholera, malaria, dysentery and typhoid.
Water treatment processes are the solution. The most common is the use of different types of filters including activated carbon electric filters, and certain commercially available water purifiers including chemicals that kill bacteria and settle the suspended solids present in water. But the use of treatment processes is very limited. Only those people who are living in cities and have some awareness of water pollution use such water treatment processes for there house hold water.
The major part of our population cannot use these utilities due to there economic situation. So the question is: how can common people get clean water? The answer is that there are certain cheaper chemicals present which can de-pollute the water. One common and traditionally used chemical is alum, better known as ‘phitkari’.
Alum has been used for drinking water treatment since 500 BC. It not only settles certain hazardous chemicals and suspended solids but also bacterial colonies. The use of alum to remove suspended solids first occurred in Egypt. During 13th to 15th centuries B.C. Egyptians developed spectacular sedimentation apparatus which used alum for drinking water treatment. Naturally occurring alum was first recognized in the deserts of Egypt.
In Southeast Asia also, naturally occurring alum has a long and colorful history of use. It has been used for centuries as a crude form of water purification in remote villages. At one time the United Nations recommended putting an “alum rock” in remote village water systems to eliminate common bacteria. Literature also suggests that naturally occurring alum was used as an anti-bacterial for minor cuts and scrapes. With sixty-five percent of the Earth’s crust made up of naturally occurring alum, it was readily available for everyday use.
Alum has also medicinal importance. It is a popular antiseptic. It is commonly used as after shave by hair cutter not only in our country but also in Europe and America. It is widely used as an antacid to relieve gastric irritation and assist in the healing of peptic ulcers. It has good acid neutralising capacity and the ability to absorb and reduce the activity of pepsin.
Alum is also used in the purification of industrial and municipal wastewater. It is a flocculating agent with the capacity to coagulate and trap solid matter which may be floating in the water, such as algae and other organic and non-organic matter. At present, alum is the primary chemical in treatment plants all over the world.
In our country clean water scarcity is worsening day by day but there are no guidelines for the use of alum
The writer
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