title: Effects of biochar on nitrogen transformation and heavy metals in sludge composting.
abstract: Composting is regarded as an effective treatment to suppress pathogenic organisms and stabilize the organic material in sewage sludge. This study investigated the use of biochar as an amendment to improve the composting effectiveness and reduce the bioavailability of heavy metals and loss of nitrogen during composting. Biochar of 0%, 1%, 3%, 5% and 7% were added into a mixture of sludge and straw, respectively. The use of biochar, even in small amounts, altered the composting process and the properties of the end products. Biochar addition resulted in a higher pile temperature (66°C) and could reduce nitrogen loss by transforming ammonium into nitrite. In the 5% biochar group, the final product from sludge composting, ammonia nitrogen, decreased by 22.4% compared to the control, and nitrate nitrogen increased by 310.6%. Considering temperature and N transformation, the treatment with 5% biochar is suggested for sludge composting.
authors.affiliation: College of Chemistry and Environmental Science, Hebei University, Baoding 071002, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: College of Chemistry and Environmental Science, Hebei University, Baoding 071002, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Huo
authors.affiliation: Institute of Plant Nutrition and Resources, Beijing Academy of Agriculture and Forestry Science, Beijing 100097, China.
authors.forename: Junxiang
authors.initials: J
authors.lastname: Xu
authors.affiliation: College of Chemistry and Environmental Science, Hebei University, Baoding 071002, China.
authors.forename: Shuxuan
authors.initials: S
authors.lastname: Liang
authors.affiliation: Institute of Plant Nutrition and Resources, Beijing Academy of Agriculture and Forestry Science, Beijing 100097, China.
authors.forename: Jijin
authors.initials: J
authors.lastname: Li
authors.affiliation: Institute of Plant Nutrition and Resources, Beijing Academy of Agriculture and Forestry Science, Beijing 100097, China.
authors.forename: Tongke
authors.initials: T
authors.lastname: Zhao
authors.affiliation: Agriculture University of Hebei, Baoding 071002, China. Electronic address: shuttwang@163.com.
authors.forename: Shutao
authors.initials: S
authors.lastname: Wang
mesh_terms: D019216:Metals, Heavy; D009584:Nitrogen; D012722:Sewage; D012987:Soil; D013696:Temperature
chemical_list: D019216:Metals, Heavy; D012722:Sewage; D012987:Soil; D009584:Nitrogen
keywords: Biochar; Composting; Heavy metal; Nitrogen