Study on Faecal Sludge Management in Kushtia Municipality and its Future Development and Sustainability

Abstract

The treatment and proper disposal of Faecal Sludge (FS) is an expensive and environmentally sensitive problem like Organic Solid Waste (OSW). The research was conducted to study the Faecal Sludge Management (FSM) in Kushtia Municipality and its future development on basis of treatment and end-use options. After data collection, Situational Assessment Tool (SAT) was used to look up the overall FSM in the municipality. Raw FS, waste water and dried FS were collected for detailed laboratory tests. Total FS generation within the municipality area is estimated at 140,798 m3/yr as per calculation, whereas Technical and Financial Assessment Tool the value is 498,926 m3/yr considering septic tank volume and 37,595 m3/yr considering per capita FS generation rate. So, total FS generation is a variable figure depending assumptions, regions, factors etc. Both drying bed dewatering efficiency and coco peat filter treatment efficiency is greatly impressive, where all treated effluent parameters are within the standard limit. Although some organic and inorganic substances are released in the water body but not destructive for aquatic animals like fish and microorganisms. The decomposition of organic compounds consumes much oxygen and leads to the decrease in BOD level. In spite of good laboratory result, reality is little dissimilar because of only 27 % raw FS treatment within 220,000 liters FS collection/ month. So a majority of collected sludge is released or discarded in natural body without any kind of treatment. COD, BOD5, TS, TSS, T.C, F.C, Alkalinity and Phosphate removal from drying beds in percentage is 98.15, 80.96, 97.35, 98.52, 95.07, 98.09, 87.76 and 99.06 respectively. After dewatering the FS, proper co-composting process with OSW a reusable product is achieved where physiochemical, microbial and heavy metals parameters are within Bangladesh compost standards and WHO guideline. Comparing test results different times done in SRDI, BARI it is revealed that, compost is still good quality on basis laboratory analysis. Specially C/N ratio would be maximum 20:1 and it was found in compost as 7.3:1. So the C/N ratio after maturation level satisfied the above suggested limits and is suitable for addition to soil. After getting results from SRDI, it is seen that, presence of heavy metals are within tolerable limit. Lead is 27 ppm and Nickel is 7 ppm in range of standard limit of 30 ppm. Other chemical constituents like Phosphorus, Potassium, Sulphur are also within standard limit which are rich sources of nutrient content in compost. Even though municipality residents are known to the FSM, compost and its impact but ministry permission besides campaigning and marketing is essential for running co-composting business. FSM will be sustainable with more FS treatment and large scale co-composting business. There is no problem in treatment as well as its value chain. Day by day population will be increased where staying the present condition won’t fulfill the FSM necessity. So it is highly necessary of more drying beds or another treatment plant in Kushtia to upgrade its FSM performance. Aimed at additional capability need to be created in future achieving its sustainability.