Water is the most abundant compound found on the earth’s surface. It covers 70.9% of the earth’s surface. It s chemical formula is H20 and in nature, it exists in liquid, solid, and gaseous forms. We may have learnt all these properties about water from our middle school years and also from the many environmentalists who tell us how we are polluting water and how fresh water resources are depleting and glaciers receding because of global warming and overuse. But then, knowing how important this element is to us, we are left with no choice but to remind ourselves everyday.
Water Sources:
Water covers 70.9% of the earth’s surface. It is found mostly in oceans which hold about 97% of surface water. Glaciers and polar ice caps hold about 2.4% and other land surface water such as rivers, lakes and ponds the remainder 0.6%. Liquid water is found in bodies of water, such as an ocean, sea, lake, river, stream, canal, pond, or puddle. The majority of water on Earth is sea water. Water is also present in the atmosphere in solid, liquid, and vapor states. It also exists as groundwater in aquifers. The main problem is not finding water but it is the depletion of fresh water and the continual polluting of water bodies.
Out of all the water on Earth, only 2.75% is fresh water, including 2.05% frozen in glaciers, 0.68% as groundwater and 0.011% of it as surface water in lakes and rivers. Most of the water we consume everyday is fresh water. But once utilized, only a small percentage of this water is recycled and reused, which is in itself an expensive process, the rest all goes as waste. Ocean water which constitutes 97% of water on earth is saline and unsuitable for daily purposes especially for drinking. Therefore, although life revolves around water, it is that 2.75% of water that is the most important and it needs to be preserved.
Water Recycling:
Rather than just discharging waste water into rivers and oceans, waste water can be recycled and reclaimed. Sewage is treated to remove solids and other impurities and can be reused for irrigation or to recharge ground water. Recycled water may not be fit for consumption purposes, but it helps in the conservation of potable or consumable water.
In many western countries, water recycling was introduced way back in the late 19th century. But in India, apart from some major metropolitan cities recycling a few percentage of waste water, it is almost non-existent in other cities to this date. With waste water just pouring into rivers, lakes or the sea, one can but imagine how long it would be before the whole eco system around these water bodies would die out and at the same time contaminating our sources of fresh water.
Treated water contains higher levels of nutrients such as nitrogen, phosphorus and oxygen which somewhat help to fertilize garden and agricultural plants when used for irrigation and as it somewhat helps reclaim nutrients to the soil it can help in increased plant growth. The usage of treated water decreases the pollution sent to sensitive environments and also decreases the usage or pumping of water from these places which benefits the eco-system and the wildlife depending on it greatly. It also lowers fresh water extraction from rivers and aquifers and therefore save more fresh water for potable purposes.
Water Harvesting:
Direct collection of rainwater and taking measures to keep that water clean by not allowing polluting activities to take place in the catchment is known as Water harvesting. The rainwater collected is stored for use at homes or establishments or to recharge the groundwater. In the hydrological cycle, rain is the first form of water while rivers, lakes and groundwater are the secondary source of water. But because of our dependence in the secondary source, we forget that rain is the source that feeds all other sources and that through water harvesting we can decrease our dependence on the other sources.
Rainwater harvesting is not a new concept or technique, and we have been using this method for decades here in India for irrigation and feeding cattle or livestock. By designing systems carefully and investing in sustainable technologies, apartments can provide or at least fulfill some of the basic water needs. Water harvesting can also replenish the rapidly depleting ground water levels, and lead to water security and sustainability.
Rainwater harvesting can assure an independent water supply during water restrictions, the quality of water is good and therefore fits the needs of many household usage and it is renewable. Although it may not be fully fit for drinking unless treated suitably. But one has to remember that rainwater harvesting systems require regular maintenance and cleaning to keep the system hygienic.
Water Treatment:
Water treatment refers to the different types of processes that make all kind of water a suitable for use for different purposes. The main aim of water treatment is to remove all kinds of pollutants and contaminants in the water so that it becomes fit for use. Different kinds of processes are utilized while treating water from physical to chemical to biological depending on the type of water required.
The two main prevalent types of water treatment are Water purification, for drinking purposes, and Sewage treatment or waste water treatment, which is basically the removing of contaminants from waste water for reuse or dispose into other water bodies. While Sewage treatment need lots of space to contain all the waste water and for the place where it is processed, water purifiers can fit even inside a kitchen.
But whatever the type of water being treated may be, the important issue is that by treating water, we are drawing lesser water from all the different water sources, as one can recycle the water, and that we are not dumping sewage water or polluted water back into the water bodies and thereby helping the environment.
