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Your search keyword '"Meng, Jun"' showing total 14 results
Start Over Author "Meng, Jun" Journal science of the total environment
14 results on '"Meng, Jun"'

13. Comparative study on the characteristics and environmental risk of potentially toxic elements in biochar obtained via pyrolysis of swine manure at lab and pilot scales

Author

Jun Meng, Henglei Zhang, Zhonghua Cui, Haipeng Guo, Ondřej Mašek, Binoy Sarkar, Hailong Wang, Nanthi Bolan, Shengdao Shan, Meng, Jun, Zhang, Henglei, Cui, Zhonghua, Guo, Haipeng, Mašek, Ondřej, Sarkar, Binoy, Wang, Hailong, Bolan, Nanthi, and Shan, Shengdao

Subjects
Environmental Engineering, Swine, Pollution, potentially toxic elements, Manure, germination index, Lead, Charcoal, Animals, Environmental Chemistry, biochar, chemical oxidation, bioavailability, Waste Management and Disposal, Pyrolysis, Cadmium
Abstract

Pyrolysis is considered as a promising method to immobilize potentially toxic elements (PTEs) in animal manures. However, comparative study on characteristics and environmental risk of PTEs in biochar obtained by pyrolysis of animal manure at different reactors are lacking. In this study, swine manure was pyrolyzed at 300–600 °C in a lab-scale or pilot-scale reactor with the aim to investigate their effects on characteristics and environmental risk of As, Cd, Cu, Ni, Pb, and Zn in swine manure biochar. Results showed that biochars produced from pilot scale had lower pH and carbon (C) content but higher oxygen (O) content than those from lab scale. Biochars from pilot scale had higher total PTEs (except Cd) concentrations and releasable PTEs (except Pb) but lower CaCl2-extractable PTEs and phytotoxicity germination index (GI) to radish seedings than those from lab scale. Chemical speciation analysis indicated that PTEs in biochar produced from pilot-scale fast pyrolysis at 400 °C had higher percentage of more stable fraction (F5 fraction) and lower potential ecological risk index (RI) than those from lab-scale slow pyrolysis. These findings demonstrated that bioavailability and potential ecological risk of PTE in swine manure biochar were greatly decrease in the pilot-scale pyrolysis reactor and the optimum temperature was 400 °C considering the lowest potential ecological risk index. Refereed/Peer-reviewed

Published
2022

14. Effects of biochar on N 2 O emission in denitrification pathway from paddy soil: A drying incubation study.

Author

Li H, Meng J, Liu Z, Lan Y, Yang X, Huang Y, He T, and Chen W

Subjects
Charcoal, Denitrification, Nitrous Oxide analysis, Oryza, Soil
Abstract

N 2 O emission from paddy soil is a potential environmental risk, especially when the soil moisture content of paddy soil changes and excessive nitrogen retention occurs. Biochar is known to have a positive effect on reducing N 2 O emissions. However, the influence of different types of biochar on N 2 O emission with varying soil moisture contents is unclear. The objective of this study was to investigate the effects of biochar made from different feedstocks and at different pyrolysis temperatures on the release of N 2 O during drying process of paddy soil. An incubation experiment with four kinds of biochar (rice straw and rice husk biochar pyrolyzed at 400 °C and 700 °C, respectively) applied at 1% (w/w) was conducted on paddy soil with the same initial moisture content (105% water-filled pore space). The emission rate of N 2 O, concentrations of ammonium and nitrate, and the abundance of N 2 O related microbial functional genes (narG and nosZ) were monitored throughout the incubation period. Biochar amendments reduced cumulative N 2 O emissions by 56.8-90.1% compared to the control. Low-temperature rice straw biochar decreased nosZ gene abundance, downregulated the denitrification pathway, and reduced nitrogen loss and N 2 O emission. The low-temperature pyrolysis rice husk biochar and the control showed similar trends in narG and nosZ gene abundance and N 2 O emission. The high-temperature pyrolysis of rice straw and rice husk biochar showed opposite trends in narG gene abundance, but both increased nosZ gene abundance at the later incubation period. Different feedback on denitrification-derived N 2 O emission in biochar application was revealed in this study by establishing a link between biotic and abiotic factors, showing that caution should be exercised when considering the use of biochar to mitigate N 2 O emission under drying soil conditions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Published
2021
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