花生壳基生物炭对生菜镉吸收和土壤pH的影响
2016-04-20张文符传良吉清妹曾建华张冬明吴宇佳刘国彪
张文 符传良 吉清妹 曾建华 张冬明 吴宇佳 刘国彪


摘 要:该文主要研究了花生壳生物炭对生菜镉吸收和土壤pH的影响,结果表明:花生壳基生物炭随着用量的增加,可使生菜产量增加9.7%~46.2%;生菜对Cd的吸收降低8.4%~38.4%;土壤有效态 Cd的含量降低7.0%~23.7%;土壤 pH值提高0.09~0.67个单位;花生壳基生物炭随着炭化温度由300℃提高到700℃,对降低生菜吸收Cd和提高土壤pH效果更显著,降低生菜地上部Cd含量21.8%~32.7%;降低生菜根系 Cd含量17.0%~30.9%;提升土壤pH值0.49~0.94个单位。
关键词:生菜;生物炭;镉吸收;土壤pH
中图分类号 S63 文献标识码 A 文章编号 1007-7731(2016)06-78-04
Effects of Peanut Husk Biochar on Absorption of Cd in Lettuce and Soil pH
Zhang Wen et al.
(Institute of Agricultural Environment and Soil,Hainan Academy of Agricultural Sciences/ Scientific Observing and Experimental Station of Arable Land Conservation(Hainan),Ministry of Agriculture,Haikou 571100,China)
Abstract:Effects of peanut husk biochar on absorption of Cd in lettuce and soil pH were studied. The results showed that lettuce production increased by 9.7%~46.2% with the increase of the amount of peanut husk biochar,the absorption of Cd in lettuce reduced by 8.4%~38.4%, the content of available Cd in soil reduced by 7.0%~23.7%,soil pH increased by 0.09~0.67 units. The effects of reducing the absorption of Cd and improving the pH in the soil is more significant with the carbonization temperature from 300℃ to 700℃,the absorption of Cd in the upper of lettuce reduced by 21.8%~32.7% and in root of lettuce reduced by 17.0%~30.9%,and soil pH increased by 0.49~0.94.
Key words:Lettuce;Peanut husk bioachar;Cd uptake;Soil pH
生物质炭(biochar)是由生物质在完全或部分缺氧的情况下经高温裂解、去除混合可燃气体和焦油后得到的一类高度芳香化难熔性固态物质,常见的生物质炭包括木炭、竹炭、秸秆炭等。生物质炭的元素组成主要包括碳、氢、氧、硫、氮等,其次为灰分元素[1]。生物质炭的含碳量与生物质最终炭化温度有关,随着最终炭化温度的升高,其含碳量增加,氢和氧的含量降低,灰分含量亦有所增加[2]。生物质炭具有多孔性、高比表面积,施入土壤后对土壤容重、孔性、CEC、微粒大小分布、吸附解吸特征都有一定影响。
施用生物质炭不仅能改善土壤理化性质、提高土壤肥力,还能吸附重金属(如福、砷、铅等),减少植物对污染物的吸收,在一定程度上达到环境修复的效果。Uchimiya等[3]对比研究了生物炭与活性炭对Cu、Ni和Cd的吸附能力,结果表明生物炭对Cu的吸附作用最大。土壤性质不同,生物炭对无机污染物的固定方式也不同,如Uchimiya等[4]通过对低Cu背景值的沙质壤土的研究,发现生物炭对Cu的吸附主要是其高CEC所致,而在高Cu背景值的碱性粘质土中,生物炭的矿质部分促进了Cu的沉淀反应。……
