ABSTRACT
Pakistan’s 77 sugar mills comprise a major industrial sector in the country, with reported production of four million metric tons of sugar during 2003-2004. In the absence of adequate pollution control measures, such a large operation brings with it the potential for significant environmental and health concerns. In addition to releases of substantial levels of air and solid waste pollutants, a major environmental challenge posed by sugar production is the large amount of pollutant-laden wastewater produced.
Nearly all stages of sugar production – occurring at the mill house, process house, boiler house, cooling pond and distillery (for mills that also produce industrial alcohol from molasses) – are water intensive, discharging waste water containing high levels of oil, suspended solids, organic matter, and chemicals. A typical wastewater management practice employed by industrial management in the country is the improper use of unlined lagoons, a potential source of contamination of underground drinking water supplies.
For the present study, sampling of water effluents was conducted at a few sugar mills in the provinces of Punjab and Sindh and the effluent samples were examined for pH, total suspended solids (TSS), total dissolved solids (TDS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), oil and grease content, and temperature. The analytical data revealed that the observed values of TSS, BOD, COD and oil and grease were higher than Pakistan’s National Environmental Quality Standards (NEQS).
This paper explores the health and environmental impacts of waste water releases from the sugar industry, particularly in terms of pollutant parameters that are found to exceed NEQS; the amount of pollution charge, as calculated under the notified government environmental rules and regulations, that the industry will have to bear over the years if it fails to comply with NEQS; and the international trade implications of not meeting environmental standards. It also appraises the technical and regulatory context in which the wastewater problem may be tackled, discussing existing environmental policies and legislation and available options including technologies for the reduction of wastewater volume and pollution load, end of pipe treatment, and recycling/reuse of waste water.