title: The use of the core-shell structure of zero-valent iron nanoparticles (NZVI) for long-term removal of sulphide in sludge during anaerobic digestion.
abstract: A core-shell structure results in zero-valent iron nanoparticles (NZVI) with manifold functional properties. In this study, the long-term effects of NZVI on hydrogen sulphide removal in an anaerobic sludge digester were investigated. Within 20 days, the average hydrogen sulphide content in the biogas was successfully reduced from 300 (or 3620 of sulphate-rich sludge) mg Nm(-3) to 6.1 (121), 0.9 (3.3) and 0.5 (1.3) mg Nm(-3) in the presence of 0.05, 0.10 and 0.20% (wt) NZVI, respectively. Methane yield was enhanced at the low NZVI dose (0.05-0.10%) but decreased at the elevated dose (0.20%). Methane production and volatile solid degradation analyses implied that doses of 0.5-0.10% NZVI could accelerate sludge stabilization during anaerobic digestion. The phosphorus fractionation profile suggested that methane production could be inhibited at the elevated NZVI dose, partly due to the limited availability of soluble phosphorus due to the immobilization of bioavailable-P through the formation of vivianite. An analysis of the reducible inorganic sulphur species revealed that the elimination of hydrogen sulphide occurred via the reaction between hydrogen sulphide and the oxide shell of NZVI, which mainly formed FeS and some FeS2 and S(0).
authors.affiliation: Nanjing Institute of Environmental Sciences of the Ministry of Environmental Protection, 210046, Nanjing, PR China. zlj@nies.org and The State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 200092, Shanghai, PR China. zhaoyoucai@tongji.edu.cn.
authors.forename: Lianghu
authors.initials: L
authors.lastname: Su
authors.affiliation: The State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 200092, Shanghai, PR China. zhaoyoucai@tongji.edu.cn and Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan.
authors.forename: Guangyin
authors.initials: G
authors.lastname: Zhen
authors.affiliation: Nanjing Institute of Environmental Sciences of the Ministry of Environmental Protection, 210046, Nanjing, PR China. zlj@nies.org.
authors.forename: Longjiang
authors.initials: L
authors.lastname: Zhang
authors.affiliation: The State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 200092, Shanghai, PR China. zhaoyoucai@tongji.edu.cn.
authors.forename: Youcai
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: The State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 200092, Shanghai, PR China. zhaoyoucai@tongji.edu.cn.
authors.forename: Dongjie
authors.initials: D
authors.lastname: Niu
authors.affiliation: The State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 200092, Shanghai, PR China. zhaoyoucai@tongji.edu.cn.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Chai
mesh_terms: D000693:Anaerobiosis; D006862:Hydrogen Sulfide; D007501:Iron / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008697:Methane; D010758:Phosphorus; D012722:Sewage / Q000737:chemistry / Q000382:microbiology; D013440:Sulfides / Q000032:analysis / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*
chemical_list: D012722:Sewage; D013440:Sulfides; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D007501:Iron; D008697:Methane; D006862:Hydrogen Sulfide