title: Effect of nickel ions on anaerobic methane production from water hyacinth.
abstract: The effect of different concentrations of nickel ions (Ni(2+), 0, 10, 40 and 80 mg/L) on the anaerobic methane production of water hyacinth were investigated. Under these four concentrations, the methane production in 40 d was 2,275, 2,703, 3,210 and 2,481 mL, respectively. This situation illustrated that the Ni(2+) promoted the growth of hydrogen-producing acetic acid bacteria and methanogenic bacteria, even at high concentrations (i.e. 40-80 mg/L). The highest methane production per unit weight water hyacinth reached 206 mL/gTS with 40 mg/L Ni(2+). Meanwhile, the modified Gompertz and Logistic equations were applied to describe the effect on anaerobic culture of Ni(2+). According to these models, the values of methane production potential (mL) for four concentrations were in the following order: 40 mg/L (3,123.42 ± 60.08) > 10 mg/L (2,541.16 ± 46.94) > 80 mg/L (2,432.36 ± 40.18) > 0 mg/L (2,238.10 ± 31.90). According to the analysis of the digestate, the residual concentration of Ni(2+) was approximately 1.05-4.9 mg/L, which was relatively low compared with the Ni(2+) concentrations in the raw feedstock. The results would provide academic guidance and technical support for treatment of water hyacinth with an accumulation of heavy metals.
authors.affiliation: Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
authors.forename: Xuan
authors.initials: X
authors.lastname: Cai
authors.forename: Zi-Jian
authors.initials: ZJ
authors.lastname: Hong
authors.forename: Rui-Hua
authors.initials: RH
authors.lastname: Dai
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.forename: Xiang
authors.initials: X
authors.lastname: Liu
mesh_terms: D000693:Anaerobiosis; D056804:Biofuels; D004305:Dose-Response Relationship, Drug; D031806:Eichhornia / Q000187:drug effects* / Q000378:metabolism*; D005285:Fermentation; D005740:Gases / Q000378:metabolism*; D008697:Methane / Q000737:chemistry / Q000378:metabolism*; D008954:Models, Biological; D009532:Nickel / Q000008:administration & dosage / Q000633:toxicity*; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000008:administration & dosage / Q000633:toxicity*
chemical_list: D056804:Biofuels; D005740:Gases; D014874:Water Pollutants, Chemical; D009532:Nickel; D008697:Methane