Affiliations: State Key Laboratory of Pulp and Paper Engineering,
South China University of Technology, Guangzhou 510641, China | Laboratory of Cellulose and Lignocellulosics
Chemistry, Chinese Academy of Sciences, Guangzhou 510650, China
Abstract: The successful application of co-immobilized aerobic-anaerobic
biomaes under limited aeration in wastewater treatment systems would eliminate
the problems associated with the intermediates mono-chlorophenol (MCP) and
di-chlorophenol (DCP) accumulations. With low initial pentachlorophenol (PCP)
concentration, all PCP could be completely removed under oxygen-limited strict
anaerobic conditions, and the removal efficiencies with different initial
haedspace oxygen percentage (IHOP) were not obviously different from each
other. While at high initial PCP concentration, under strictly anaerobic
conditions PCP and their intermediates were clearly higher than that under
other conditions, and produced obvious accumulation, the highest PCP reduction
was achieved by the system receiving 30 IHOP, oxygen-limited system also
exhibited lower residual TOC concentration and lower concentration of metabolic
intermediates MCP and DCP. These results suggested that under strictly
anaerobic condition the reductive dechlorination of low chlorinated compounde
became rate limiting in the reductive dechlorination pathway, less chlorinated
compounds be more amenable to aerobic degradation, and the aerobes of outer
layers could function under limited oxygen. The co-immobilized
aerobic-anaerobic biomass for methanogeneeis under limited-aeration for
chlorophenol degradation might be an attractive and efficient altemative for
the sequential anaerobic/aerobic system to achieve mineralization of a broad
range of recalcitrance highly chlorinated organics and low final TOC
concentrations.
