The addition of lamella in anaerobic baffled reactor used for decentralized municipal wastewater treatment

An anaerobic baffled reactor (ABR) represents a low-cost system for decentralized wastewater treatment in a developing country. Despite the advantages of ABR units such as low operating and maintenance costs, this system requires sufficient land to construct it. In particular of an urban area, land availability is limited and therefore acquire modification in ABR design. This study aimed to test the addition of lamella for further reduction of solids particle in domestic wastewater, and therefore it could reduce the size of ABR settler. A lab-scale of an ABR lamella with a dimension of 75 cm length, 20 cm width, and 40 cm height used in the experiment. A 20 L/d of raw municipal wastewater taken from the existing ABR in Kampong Bareng, Malang (Indonesia) used to feed the lab-scale of the ABR lamella. The experiment was conducted in two months and the sample of raw and treated wastewater collected from the ABR lamella for ten times from September to October 2018. The samples were taken from the inlet, lamella compartment, and the outlet. The results showed that the addition of lamella reduced the concentration of TSS and BOD for 95% and 90% respectively. While these results could help further reduction of organic and solids particle of wastewater that meet the treated wastewater regulation. The concentration of TSS and BOD as treated wastewater were 19 mg/L and 18 mg/L respectively. Although the ABR could reduce the nutrient concentration, the level still higher than the global standard for N and P. (paper)