Adaptation of effective consortium bacteria for ammonia removal from domestic wastewater using moving bed biofilm reactor

Abstract

Three effective microbes with the highest ammonia removal potential which are Burkholderia latens isolate NS2, Paenibacillus sp. isolate NB1 and Providencia rettgeri isolate PS were acclimatized with synthetic wastewater for 85 days (∼3 months) to achieve a stable and maximum removal of ammonia (NH3-N) and chemical oxygen demand (COD) from domestic wastewater. The objective of this paper is to investigate the adaptation of effective consortium bacteria for a low-cost technology of ammonia and COD removal. Synthetic wastewater was used as it provides sufficient food sources such as carbon, nitrogen and phosphorus for microbes growth. The process was carried out in a 60 L working volume of moving bed biofilm reactor (MBBR) in a batch mode. Propylene hexafilter media was used as a surface attachment for microbes. Microbes attachment at the hexafilter media was observed increased although the aeration was maintained at low flowrate which is at 2.6 L/min. The initial value of ammonia fed into the reactor was 10 mg/L. The highest NH3-N removal percentage achieved was 96.5% with average effluent at 0.82 mg/L at day 75 in 24 h while the highest COD removal percentage achieved was 95.9% with average effluent at 39 mg/L at day 58 in 24 h. The bacteria consortium are considered flexible as it can adapt to low and high COD and able to remove NH3-N at room temperature. The SEM shows the presence of bacteria consortium on the hexafilter carrier. As conclusions, this finding indicates that consortium bacteria can treat domestic wastewater containing ammonia and COD to support the National Water Quality Standard.