A laboratory-scale study of the applicability of a halophilic sediment bioelectrochemical system for in situ reclamation of water and sediment in brackish aquaculture ponds: establishment, bacterial community and performance evaluation.

In this study, we investigated the potential of using sediment bioelectrochemical systems (SBESs) for in-situ treatment of the water and the sediment of brackish aquaculture ponds polluted with uneaten feed. A SBES integrated into a laboratory-scale tank simulating a brackish aquaculture pond was established. Such a tank (test tank) and the control (not containing the SBES) were fed with shrimp feed in a scheme that mimics a situation where 50% of feed is uneaten. After the SBES was inoculated with microbial sources from actual shrimp pond sediments, electricity generation was well observed from the first experimental week, indicating a successful enrichment of electrochemically active bacteria at the sediment of the test tank. The electricity generation became steady after 3 weeks of operation, with an average current density of 2.3 mA m-2 anode surface and an average power density of 0.05 mW m-2 anode surface. At the steady state, the SBES removed 20-30% more COD of the tank water, compared to the control. After 1 year, the SBES also reduced the amount of the sediment in the tank by 40% and thus could remove approximately 40% more COD and approximately 52% more nitrogen of the sediment, compared to the control. Insignificant amount of nitrite and nitrate was detected, suggesting a complete removal of nitrogen by the system. PCR-DGGE-based analyses revealed the dominant presence of Methylophilus rhizosphaerae, Desulfatitalea tepidiphila and Thiothrix eikelboomii, which have ...
Source: Journal of Microbiology and Biotechnology - Category: Biotechnology Authors: Tags: J Microbiol Biotechnol Source Type: research