Characterization of the liquid waste of sugar mills in Bangladesh

Abstract

Fifteen (l5)Nos of Govt. owned Sugar Mills in the Northern & South-west zone of Bangladesh comprise a major industrial sector in the country. Bangladesh Sugar & Food Industries Corporation (BSFIC-owner of these sugar mills) considered being one of the best-organized agro-based industrial sectors in the country. These industries produced nearly 1.65 lac metric tons of sugar during 2006-07 season and has a full production capacity estimated at 2. I 0 lac metric tons. 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 in the large amount of pollutant-laden wastewater produced. The study work has been performed to study and analyze the characteristics of effluent water of Sugar industries in Bangladesh.The present study was conducted through collecting of 14 Nos running ~ugar Mill's (BSFIC) effluent water, and the effluent samples were examined for pH, BODs COD, Hardness, TOS, SS, TS, inorganic substances (Nitrogen, Sulphate, Chlorides), colour and Turbidity. From this sample the test results collected from the Environmental engineering Laboratory, BUET and then analysed by using computer software (EXCEL). The study reveals that in most cases, the concentration of these parameters exceed for some sugar mills within the respective maximum permissible limits suggested by Environmental Quality Standrads of Bangladesh. Generally the waste(Effluent water) contain medium to high BODs, COD loading, high suspended & dissolved solids and strong colour. The major pollutants in terms of total waste load generated and ranked in order of contributing the highest biodegradable load are B005= I04-8200mg/l, COO=140-12000mgll. The effluent quality e.g BODs and COD of all Sugar Industries exceeded the EQS limit. These sugar mills (BSFIC) needed to be properly treated and maintained before discharged into a surface water body. The average B0051COO ratios found for all sugar Mill are higher than 0.67; so that all of the Sugar industrial effluents are biologically treatable without acclimatization.