title: Nitrogen removal from coal gasification wastewater by activated carbon technologies combined with short-cut nitrogen removal process.
abstract: A system combining granular activated carbon and powdered activated carbon technologies along with shortcut biological nitrogen removal (GAC-PACT-SBNR) was developed to enhance total nitrogen (TN) removal for anaerobically treated coal gasification wastewater with less need for external carbon resources. The TN removal efficiency in SBNR was significantly improved by introducing the effluent from the GAC process into SBNR during the anoxic stage, with removal percentage increasing from 43.8%-49.6% to 68.8%-75.8%. However, the TN removal rate decreased with the progressive deterioration of GAC adsorption. After adding activated sludge to the GAC compartment, the granular carbon had a longer service-life and the demand for external carbon resources became lower. Eventually, the TN removal rate in SBNR was almost constant at approx. 43.3%, as compared to approx. 20.0% before seeding with sludge. In addition, the production of some alkalinity during the denitrification resulted in a net savings in alkalinity requirements for the nitrification reaction and refractory chemical oxygen demand (COD) degradation by autotrophic bacteria in SBNR under oxic conditions. PACT showed excellent resilience to increasing organic loadings. The microbial community analysis revealed that the PACT had a greater variety of bacterial taxons and the dominant species associated with the three compartments were in good agreement with the removal of typical pollutants. The study demonstrated that pre-adsorption by the GAC-sludge process could be a technically and economically feasible method to enhance TN removal in coal gasification wastewater (CGW).
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China. Electronic address: han13946003379@163.com.
authors.forename: Hongjun
authors.initials: H
authors.lastname: Han
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
authors.forename: Baolin
authors.initials: B
authors.lastname: Hou
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Zhuang
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
authors.forename: Shengyong
authors.initials: S
authors.lastname: Jia
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Fang
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics; D001483:Base Sequence; D003031:Coal; D017931:DNA Primers; D058645:Denaturing Gradient Gel Electrophoresis; D005740:Gases / Q000737:chemistry*; D009584:Nitrogen / Q000302:isolation & purification*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D062065:Wastewater / Q000737:chemistry*
chemical_list: D003031:Coal; D017931:DNA Primers; D005740:Gases; D009584:Nitrogen; D062065:Wastewater
keywords: Coal gasification wastewater; Denitrification enhancement; Granular activated carbon; PCR-DGGE; Short-cut nitrogen removal