Mobility and phytoavailability of As and Pb in a contaminated soil using pine sawdust biochar under systematic change of redox conditions.
Biochar has been adopted to control the mobility and phytoavailability of trace elements (TEs) in soils. To date, no attempt has been made to determine the mobility and phytoavailability of arsenic (As) and lead (Pb) in a contaminated soil with biochars as amendments under predefined redox potentials (EH). Thus, in this study, a soil contaminated with As and Pb (2047 and 1677 mg kg-1, respectively) was pre-incubated for 105 days with three amendments (pine sawdust biomass (BM) and two biochars produced from the same feedstock at 300 °C (BC300) and 550 °C (BC550)). The aged samples were then exposed to dynamic EHconditions to evaluate the mobility and phytoavailability of As and Pb after immobilization. The BM amendment significantly decreased and the BC300 slightly reduced the mobility and phytoavailability of As and Pb, which may be related to the oxygen-containing functional groups on the surface of BM and BC300. In contrast, BC550 increased the mobility of As at -300 to -100 mV and 100 mV, enhanced the phytoavailability of As under oxidizing condition (>100 mV), but reduced the phytoavailability of Pb, which might be caused by the properties of amendments and redox chemistry of the TEs. The effectiveness of BM and biochars for the stabilization of As and Pb varied under dynamic EHconditions, which indicates that detailed investigations should be conducted before the applications of biochar as soil amendment under variable environmental conditions, especially for contaminated paddy soils.
Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
Jingzi
J
Beiyuan
School of Natural Resources and Environmental Science & Korea Biochar Research Center, Kangwon National University, Chuncheon 24341, Republic of Korea; Faculty of Agriculture, Suez Canal University, Ismailia 41522, Egypt.
Yasser M
YM
Awad
University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany.
Felix
F
Beckers
Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
Daniel C W
DC
Tsang
School of Natural Resources and Environmental Science & Korea Biochar Research Center, Kangwon National University, Chuncheon 24341, Republic of Korea; University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany.
Yong Sik
YS
Ok
University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; Department of Environment and Energy at Sejong University, 98 Gunja-Dong, Guangjin-Gu, Seoul, Republic of Korea. Electronic address: rinklebe@uni-wuppertal.de.
Jörg
J
Rinklebe
D001151:Arsenic / Q000032:analysis* / Q000737:chemistry; D002606:Charcoal / Q000737:chemistry*; D004787:Environmental Pollution; D007854:Lead / Q000032:analysis* / Q000737:chemistry; D010084:Oxidation-Reduction; D028223:Pinus / Q000737:chemistry*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry
D012987:Soil; D012989:Soil Pollutants; C540010:biochar; D002606:Charcoal; D007854:Lead; D001151:Arsenic
Charcoal; Immobilization; Redox processes; Soil remediation; Trace elements