Simultaneous removal of carbon, sulfur, and nitrogen from biological synthetic wastewater: aerobic and anaerobic approach

• DOI: 10.1007/s12517-019-4346-8
• Publication Date: 2019-02-27T16:33:34Z
• Authors: Saima Fazal; Hao Xu; Xinrong Xu; Shaobin Huang; Yongqing Zhang; Arshad Ali; Waseem Hayat; Yingying You; Xiaodong Du; Zahid Ullah
• Keywords: Aerobic denitrification; Carbon fibers; Anammox

Previously, wastewaters containing organic matter such as sulfur and other nitrogenous compounds were treated by employing separate biotechnologies. The current investigation investigated simultaneous carbon, nitrogen, and sulfur removal in single bioreactor under oxygen and oxygen deficient experimental conditions. Two separate bioreactors (aerobic and anaerobic) were operated under similar mesophilic conditions. It was revealed that the products of COD, nitrate, and sulfate mainly depended on the medium pH which was the main determining factor. The substrates ratios like C:N, C:S, and N:S could result in the diverse end products. Under aerobic conditions, COD completely degraded into CO2 and H2O, nitrate was anticipated to be converted as ammonium through dissimilatory nitrate reduction to ammonium which could become part of cellular metabolism. The bulk of sulfate was converted to elemental sulfur. While the results of anaerobic digestion showed that COD mainly contributed to methanogenesis, the COD conversion was lower as compared with the aerobic conversion. Nitrate was anticipated to be converted to nitrogen gas via denitrification. However, mass balance suggested lower amount of elemental sulfur formed as compared with aerobic treatment. Such information may help to understand complex nature of bacterial interactions employed in aerobic and anaerobic wastewater treatments.