School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China.
Shanghai Entry-Exit Inspection and Quarantine Bureau, Shanghai 200135, PR China.
Sci Total Environ. 2016 Nov 1;569-570:1-8. doi: 10.1016/j.scitotenv.2016.06.092. Epub 2016 Jun 17.
Biochar has been explored as a cost-effective sorbent of contaminants, such as soil fumigant. However, contaminant-loaded biochar probably becomes a source of secondary air pollution. In this study, biochars developed from cow manure and rice husk at 300°C or 700°C were used to investigate the catalytic degradation of the soil fumigant 1,3-dichloropropene (1,3-D) in aqueous biochar slurry. Results showed that the adsorption of 1,3-D on the biochars was influenced by Langmuir surface monolayer adsorption. The maximum adsorption capacity of cow manure was greater than that of rice husk at the same pyrolysis temperature. Batch experiments revealed that 1,3-D degradation was improved in aqueous biochar slurry. The most rapid 1,3-D degradation occurred on cow manure-derived biochar produced at 300°C (C-300), with t1/2=3.47days. The degradation efficiency of 1,3-D on C-300 was 95.52%. Environmentally persistent free radicals (EPFRs) in biochars were detected via electron paramagnetic resonance (EPR) techniques. Dissolved organic matter (DOM) and hydroxyl radical (·OH) in biochars were detected by using a fluorescence spectrophotometer coupled with a terephthalic acid trapping method. The improvement of 1,3-D degradation efficiency may be attributed to EPFRs and DOM in aqueous biochar slurry. Our results may pose implications in the development of effective reduction strategies for soil fumigant emission with biochar.
生物炭已被探索作为一种具有成本效益的污染物吸附剂，例如土壤熏蒸剂。然而，负载污染物的生物炭可能成为二次空气污染的来源。在这项研究中，使用在 300°C 或 700°C 下由牛粪和稻壳制成的生物炭来研究土壤熏蒸剂 1,3-二氯丙烯（1,3-D）在水相生物炭浆中的催化降解。结果表明，1,3-D 在生物炭上的吸附受 Langmuir 表面单层吸附的影响。在相同的热解温度下，牛粪的最大吸附容量大于稻壳。批实验表明，在水相生物炭浆中 1,3-D 的降解得到了改善。在 300°C 下制备的牛粪衍生生物炭（C-300）上，1,3-D 的降解最快，t1/2=3.47 天。C-300 上 1,3-D 的降解效率为 95.52%。通过电子顺磁共振（EPR）技术检测到生物炭中的环境持久性自由基（EPFRs）。通过荧光分光光度计与对苯二甲酸捕获法联用检测生物炭中的溶解有机物质（DOM）和羟基自由基（·OH）。1,3-D 降解效率的提高可能归因于水相生物炭浆中的 EPFRs 和 DOM。我们的结果可能对开发使用生物炭有效减少土壤熏蒸剂排放的策略具有启示意义。
