UASB treatment of chemical synthesis-based pharmaceutical wastewater containing rich organic sulfur compounds and sulfate and associated microbial characteristics

Abstract

h i g h l i g h t sSuccessful application of UASB in treatment of rich organic S-bearing wastewater. Sulfate in effluent was higher than influent at COD/SO 4 2À ratio of 8 and 5.Conversely, sulfate in influent was higher than effluent at COD/SO 4 2À ratio of 1.5.Archaea and bacterial community varied greatly with altered OLR. Some species can be responsible for S release from organic sulfur compounds.a r t i c l e i n f o a b s t r a c tThe feasibility of treating of chemical synthesis-based pharmaceutical wastewater containing rich organic sulfur compounds and sulfate using an upflow anaerobic sludge blanket (UASB) was investigated. The initial COD/SO 4 2À ratio of 8 in the wastewater varied from 5 to 1.5 after adding sulfate. Of interest that under the condition of COD/SO 4 2À at 8 and 5, despite the simultaneous generation of sulfide and hydrogen sulfide, the sulfate concentration in the effluent was higher than in the influent. This is due to the sulfur release in the form of sulfate during the degradation of these organic sulfur compounds in this reactor. Conversely, at COD/SO 4 2À of 1.5, influent sulfate was higher than effluent sulfate due to reduction of more sulfates in the reactor. At COD/SO 4 2À of 8, for practical application, the optimum OLR was found to be 8 kg COD/m 3 /d, where a nearly 70% COD reduction occurred with biogas containing 63% methane. In this stage, the distribution of the archaea and bacterial community varied greatly with altered OLR (accompanied with prolonged operation time). Some species, such as Lysinibacillus sphaericus, Clostridium cellulovorans were expected to be partly responsible for S release from some organic sulfur compounds in the reactor. By increasing the sulfate loading at a COD/SO 4 2À ratio up to 1.5 resulted in a light inhibition of methanogenesis due to the high sulfide concentration (1212 SO 4 2À -S mg/L) with no obvious suppression of sulfidogenesis.

Bacterial community analysis of anoxic/aeration (A/O) system in a combined process for gibberellin wastewater treatment

“…Nevertheless, Li. et al [ 5 ] investigated the treatment of chemical synthesis-based pharmaceutical wastewater containing rich organic sulfur compounds and sulfate using an Upflow Anaerobic Sludge Blanket (UASB) reactor. They found that this method removed a considerable amount of COD and sulfate.…”

Diversity and degradation mechanism of an anaerobic bacterial community treating phenolic wastewater with sulfate as an electron acceptor

“…The UASB reactor in this study had a lower COD removal efficiency than other anaerobic reactors, which was probably because the H 2 S produced during sulfate reduction had a toxic effect on the activated sludge and methanogenesis was more sensitive to H 2 S than the SRB (Li et al 2015). The high concentration of phenol obviously inhibited the SRB, resulting in the drop of H 2 S concentration, which had a lower toxicological effect on the methanogens.…”

Improving hydrolysis acidification by limited aeration in the pretreatment of petrochemical wastewater

“…The variation of BOD 5 /COD in influent, limited aeration and anaerobic effluents. wastewater (Li et al, 2015), causing the increase of SO 2À 4 in Period III and Period IV.…”