Speaker: Md Tawhidur Rahaman
Bio-Let is a technological solution where the sludge and wastewater managed through an environment-friendly manner. In this system, human waste is decomposed by inoculums bacteria in the settler tank and passes through the anaerobic baffled reactor and finally at a polishing pond. Bio-Let technology is based on anaerobic biodegradation of organic waste by the unique microbial consortium. It works at a wide temperature range, so the end product is water & Biogas (no night soil). The main objective of the work is to make the septic tank more efficient.
In Bangladesh, secondary level treatment of sludge is a new concern for the sector actors as Bangladesh has achieved significant progress on reducing open defecation, which comes down from 18% in 2000 to zero in 2015, according to the SDG baseline. However, this achievement subsequently delivers a key question on how to manage this sludge and wastewater safely. In the context of Bangladesh, this wastewater and sludge from latrines and septic tanks are emptied and released untreated into the local environment. Both in rural and urban areas, there is lack of treatment facilities for both wastewater and faecal sludge. In Dhaka city, 80% residents live in informal settlements unauthorized, densely packed, and prone to flooding, with no proper toilets or running water. Raw sewage drains out directly into an open drainage system. Only 20% of the total households are under the coverage of the sewerage system. This study is investigating pollutant removal performances (from wastewater) of biolet treatment system, which is constructed at M.D.C Model Institute, Mirpur, Dhaka. The purpose of Bio-Let is to provide an environment-friendly sanitation technology for school sanitation, which is manageable and affordable for the school authority.
Bio-Let terminates the residual human excretory waste. During heavy rainfall, the areas logged into the water, and the faecal matters get mixed in with an open environment, which results in serious public health risks. The main objective of this technology is to make the septic tank more efficient and concentrate on the volume of sludge. The influent concentration profiles across the biolet were highly variable with respect to experimental days. However, effluent profiles were comparatively stable; in addition, effluent values were lower when compared with influent values. A laboratory analysis has been done and found ≥ 95% BOD, TSS and E. Coli removal percentage in the BioLet where, NH4-N, TKN, TN and TP removal percentage ranged between 50-70%. floating wetland is being constructed and integrated with the biolet for further improving effluent quality. Combined performance of biolet-floating wetland is under monitoring process.
A. A. Muyeed (2015)
Innovation for second generation sanitation
Journey to Zero Sanitation conference.