Recycle waste water for a cleaner future

Sunil Ghorawat

Ninety per cent of waste water in developing countries is released without any kind of treatment, according to a recent report by the World Health Organisation (WHO).

While limited availability of fresh water and its unequal distribution make water pollution a matter of serious concern, for India the situation is even more grave as 70 per cent of its fresh water is polluted, including several high altitude lakes.

While water pollution is easier to study and monitor, its control is highly complex and costly. In such a situation, recycling and re-using waste water is the best option for industries.

Recycling water from effluents not only reduces the expense on water but also leads to other benefits.

First, recycled water becomes an assured source of supply as long as an industry operates and effluents are generated. Industry may think recycling is a complicated and expensive process. But this is not so. Most industries can opt for simple water treatment schemes.
Second, reusing effluent reduces fresh water consumption and cuts expenses. For instance, in Goa, some industries spend as much as Rs 26 per m3 of raw water.

Three, if an industry has expansion plans and sufficient water is not available, then recycling can reduce costs, thereby cutting capital investment. Compared to shifting the factory to another location, installing a water recycle plant is more economical, logical and environment-friendly.

Fourth, recycling will decrease effluent discharge thus reducing sewerage charges. The combined fee for water and sewer use has been on the rise for quite some time now and is expected to go higher. In Mumbai, an industry pays over Rs 8 per m3 of effluent discharged into the sewer.

Fifth, by using appropriate separation technologies, it is technically possible and financially feasible to recover valuable contaminants from effluents that can pay back investments in the recycle plants by saving on raw material use, recovering valuable product and by reducing costs in effluent treatment because the contamination load has reduced.

Reusing industrial and domestic waste water is fast gaining popularity. One of the earliest examples of water recycle was in the Union Carbide factory in Chembur, Mumbai, where domestic sewerage was treated and reused. Waste water recycling was also carried out by Madras Refineries Ltd, Madras Fertilisers Ltd, Arvind Mills and at Iffco Phulpur.

It is necessary, therefore, that water technologists and industry experts adopt an integrated approach to treat and recycle water in industry. Big industrial houses have the necessary technical and financial resources to put in place pollution control processes and equipment. But small and medium industrial units, whose number is large, lack finances and technical know-how. It is necessary to provide them financial support for installing anti-pollution devices. Financial institutions should be entrusted the task of providing soft loans to these units. The state pollution control boards’ role expanded to include technical guidance to these enterprises.

The other important measure is a properly designed land use policy. The land use pattern should be so decided that small and medium units are aggregated with common effluent treatment facilities. In addition, all industrial activity should be shifted out of densely populated areas.

(The writer is CEO, EAWater Pvt. Ltd)