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Variation of microbiological and physicochemical properties of untreated (inlet) and treated (outlet) faecal sludge samples of different treatment plants in the existing FSM technologies from the 5th round of sampling in the Rohingya Camps, Cox’s Bazar

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Bangladesh
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Sources
ICDDR,B
+ 1
Date de publication
Origine
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Background:

Human excreta (faeces and urine) are waste matters discharged from the body due to several physiological activities. Faecal Sludge (FS), the mix of human excreta, anal cleansing material, water, detergents, rubbish, disinfectants, is a slurry or semisolid that is raw or partially digested and comes from onsite sanitation technologies, which include pit latrines and septic tanks.

Since the influx of 2017 from Rakhine state, about 1.3 million Rohingya people have been living in a highly-populated condition exceeding around 290,000 people per square kilometer in Cox’s Bazar district. Numerous latrines (40,000) have been installed to fill up the sanitation need for a highly dense population at Rohingya camps. When the pit latrines are full, improper collection, transportation, treatment followed by inappropriate management of discharge increase health risk for the inhabitants as well as exacerbate environmental pollution. As per the Bangladesh Environment Conservation Act, 1995, proper management of sludge is mandatory. Presently, various technologies are being used to treat the faecal sludge at Rohingya camps, such as Up-flow filters, Constructed wetlands, Lime stabilization ponds, Anaerobic baffled reactor, Anaerobic treatment systems, and Wastewater stabilization ponds. As a part of the total efficacy testing (1 year) of the above-mentioned treatment technologies, we planned to perform monthly analysis of microbiological and physicochemical parameters of the untreated and treated faecal sludge samples collected from the plants of those treatment technologies.

Purpose of the Report:

This report provides the variation of microbiological and physicochemical properties of untreated (inlet) and treated (outlet) faecal sludge samples of selected FSM plants under different treatment technologies at round-5 (March 05, 2020, to March 22, 2020) in the Rohingya Camps, Cox’s Bazar. This report also shows the comparison of the quality of treated effluent with the different existing national and international effluent/sewage discharge guidelines.

Summary:

This report is aimed to provide evidence-based information on the microbiological and physicochemical quality of faecal sludge samples collected from different FSM plants of the Rohingya camps in Cox’s Bazar. Total 18 plants (both UNICEF and Non-UNICEF funded) from six (6) different technologies were selected initially for comparison. We used Geo tube only in round 1 but due to unavailability, later on from round 2 to round 5, we had to exclude this treatment technology as it has been decommissioned. Moreover, we also excluded anaerobic lagoon from our list from the very 1st round due to the unavailability of our purpose. To compensate them we had included two (2) other new technologies, Wastewater stabilization ponds and anaerobic treatment system in our study. Different NGOs are involved in operating these FSM plants. The operation procedure of different technologies is also different. Hence, to determine the efficacy of those different FSM treatment technologies, we performed twelve (12) microbiological and physicochemical tests and analyzed the tested data of round-5. The sample collection was started on March 05, 2020, and ended on March 22, 2020. The samples were transported by air shipment from Cox’s Bazar to the Laboratory of Environmental Health, icddr,b Dhaka maintaining the cold chain and processed according to the standard procedures.

There are many international guidelines to test the efficiency of faecal sludge treatment based on types of technology, types of faecal matters being treated, and end product uses policies. But, to compare the efficiency of all six (6) technologies used in our study, following parameters such as E. coli, pH, COD, BOD, NO3, Total Nitrogen (TN), Ammonium (NH4), Phosphate (PO4 3-), Total Phosphorous (TP), Total Solids (TS), Temperature, and Total Suspended Solids (TSS) were tested from both the inlet as well as the outlet samples of the selected treatment plants at round 5. As a part of efficacy testing, microbiological and physicochemical parameters of the treated sludge (outlet) is also compared with the different existing national and international effluent/sewage discharge guidelines.