Guest Column| Punjab’s Zira factory protest: Treat, recycle and monitor

Wastewater generated by any ethanol-producing plant is a threat to the environment for its safe disposal due to its high content of toxic compounds. There is no one-step treatment of the effluent from the distillery. The multi-stage treatment methods make the process energy-intensive

Much before the third world, the developed countries became aware of the environmental degradation associated with industrialisation. As environmental laws became more stringent for the management of wastewater streams, the cost of effluent treatment also increased exponentially.

Police trying to evict protesters on December 21 after farmers joined the five-month-long agitation by local residents against a newly set up private ethanol industry near Zira town in Ferozepur district of Punjab. (HT file photo)

This was one of the reasons that many manufacturing units were installed in third-world countries where the handling and disposal of such industrial effluents become cost-effective because the environmental norms are flouted with impunity. That is why we come across such alarming levels of water pollution, in many places in the Indian context, where these industries are flourishing without wastewater treatment protocols.

The toxic and hazardous effluents are just injected by pressure, deep into the second strata of water, underneath the surface of the earth. The outcome is poisonous drinking water, a cocktail of unwanted minerals, organic matter, and heavy metals that brings a wide range of ailments from allergies, respiratory tract diseases, and cancer to genetic mutations in people, who have no choice but to consume the polluted water.

Such apprehensions are at the centre of the five-month-long agitation by local residents against a newly established private ethanol industry near Zira in Ferozepur district of Punjab. The production of sugar from sugarcane generates several waste products such as bagasse, press mud, and molasses. Molasses is the final residue from sugar crystallisation. It is used as a raw material to produce several products and one of them is ethanol. Ethanol production produces molasses wastewater (MW), which is a high-strength wastewater.

Effluent contains heavy metals

On an average, 1 tonne of molasses produces 0.2 tonnes of alcohol and generates 2.5 to 3 tonnes of MW. In simpler terms, the production of 1 litre of ethanol generates 10 to 15 litres of MW. MW is treated anaerobically and the effluent generated after the treatment is called AMW. But the process is unable to remove the dark brown colour and a strong odour in the effluent.

The alarming point is that the (AMW) effluent even after the anaerobic treatment contains high values of COD (chemical oxidation demand) and BOD (biochemical oxidation demand). World Health Organisation (WHO) norms say that an effluent with a BOD of less than 5mg/l is ideal for discharge into water bodies. At this limit, BOD will not cause any harmful impacts on the human body.

Similarly, the COD values of the effluent that can be safely discharged to a water body should be around 75-100 mg/l. The AMW effluent, even after it is put through anaerobic treatment, has COD values that are 300-1,000 times higher than the permissible limits and the BOD values of the AMW are also 200-600 times higher than permissible limits.

Typically, AMW effluent does not have phosphorus (P) but it contains heavy metals such as barium (Ba), mercury (Hg), and selenium (Se) at concentrations quite higher than the limits set by the WHO for discharging the effluents into a water body. These heavy metals invariably end up in the drinking water system and have deleterious effects on human beings.

High cost of waste treatment

Wastewater generated by any ethanol-producing plant is a major threat to the environment for its safe disposal due to their high content of toxic inorganic and organic compounds. There is no one-step treatment of the effluent from the distillery. The multi-stage treatment methods, being employed at present, make the process energy-intensive. High costs associated with establishing a proper system to treat the DW renders it economically unattractive for the industry. That may be the reason why Malbros Industries, engaged in ethanol production at Zira, might not be employing a proper treatment system for its effluents and discharging the untreated or partially treated effluents into a water body, or injecting deep into the second strata of water aquifer underneath, or discharging it onto the land.

It is easy for any scientific investigating agency to establish whether Malbros Industries is following the protocol or flouting norms with impunity. And, whether there is a link, if any, between the distillery effluents and water being pumped out by the neighbouring borewells in farmland. A detailed examination of the DW and the treated effluent needs to be established with modern techniques. A reputed laboratory having access to these advanced analytical techniques should be involved other than the laboratories at Punjab Pollution Control Board and Punjab Agricultural University.

Industrial production, of any kind, will always result in one kind or the other environmental degradation. A pollution-free environment is inconceivable with industrialisation. The laxity and the lack of will on the part of monitoring agencies in the enforcement of anti-pollution laws give polluters a free run to continue business as usual. Hence, it becomes important that anti-pollution laws are enforced properly. It is important to treat and recycle the wastewater generated by industries so that economic growth and ecological conservation can go hand in hand. sanjeevpau@yahoo.ca

Sanjeev Ahluwalia (HT Photo)

The writer, an alumnus of Punjab Agricultural University, Ludhiana, is a Vancouver-based specialist in energy sciences and technology