title: Soil properties and microbial ecology of a paddy field after repeated applications of domestic and industrial sewage sludges.
abstract: The effects of repeated application of two types of sewage sludge, domestic and industrial (petrochemical, PSS) sludges, into paddy fields over a 5-year period on the soil properties and microbial ecology were studied and compared with conventional NPK fertilizer application. Soil organic matter and total nitrogen contents were significantly higher in the two sludge treatments than that in fertilized plots after 5 years. Soil concentrations of potentially toxic metals were low after 5 years of both sludge treatments, but the polycyclic aromatic hydrocarbons (PAHs) showed differences between the two sludge types. Concentrations of high-molecular-weight PAHs were significantly higher (p < 0.05) in the petrochemical sludge treatment than the domestic sludge treatment or the fertilizer control, although the total concentrations of 16 types of PAH in the petrochemical sludge treatment were only slightly higher than in the domestic sludge treatment and the control. The biological toxicity of soil dimethyl sulfoxide extracts from the petrochemical sludge treatment was also significantly higher (p < 0.05) than those from the fertilizer control and the domestic sludge treatment when evaluated using Photobacterium phosphoreum T3. Both types of sewage sludge increased soil microbial activity, but only the petrochemical sludge led to enrichment with specific PAH degraders such as Mycobacterium, Nocardioides, and Sphingomonas.
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Liu
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China. liuwuxin@issas.ac.cn.
authors.forename: Wuxing
authors.initials: W
authors.lastname: Liu
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.
authors.forename: Qingling
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.
authors.forename: Longhua
authors.initials: L
authors.lastname: Wu
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.|Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, China.
authors.forename: Yongming
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.
authors.forename: Peter
authors.initials: P
authors.lastname: Christie
mesh_terms: D005308:Fertilizers; D019216:Metals, Heavy / Q000032:analysis; D009584:Nitrogen / Q000032:analysis; D011084:Polycyclic Aromatic Hydrocarbons; D012722:Sewage / Q000737:chemistry; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology
chemical_list: D005308:Fertilizers; D019216:Metals, Heavy; D011084:Polycyclic Aromatic Hydrocarbons; D012722:Sewage; D012987:Soil; D009584:Nitrogen
keywords: Biological toxicity; Industrial sludge; Microbial activity; Paddy soil; Polycyclic aromatic hydrocarbons; Sludge application