Gregory Samuel J, Anderson Christopher W N, Camps-Arbestain Marta, Biggs Patrick J, Ganley Austen R D, O'Sullivan Justin M, McManus Michael T
New Zealand Biochar Research Centre, Massey University, Palmerston North, New Zealand.
Soil and Earth Sciences, Institute of Agriculture and Environment, Massey University, Palmerston North, New Zealand.
PLoS One. 2015 Apr 29;10(4):e0125393. doi: 10.1371/journal.pone.0125393. eCollection 2015.
We examined the effect of biochar on the water-soluble arsenic (As) concentration and the extent of organochlorine degradation in a co-contaminated historic sheep-dip soil during a 180-d glasshouse incubation experiment. Soil microbial activity, bacterial community and structure diversity were also investigated. Biochar made from willow feedstock (Salix sp) was pyrolysed at 350 or 550°C and added to soil at rates of 10 g kg-1 and 20 g kg-1 (representing 30 t ha-1 and 60 t ha-1). The isomers of hexachlorocyclohexane (HCH) alpha-HCH and gamma-HCH (lindane), underwent 10-fold and 4-fold reductions in concentration as a function of biochar treatment. Biochar also resulted in a significant reduction in soil DDT levels (P < 0.01), and increased the DDE:DDT ratio. Soil microbial activity was significantly increased (P < 0.01) under all biochar treatments after 60 days of treatment compared to the control. 16S amplicon sequencing revealed that biochar-amended soil contained more members of the Chryseobacterium, Flavobacterium, Dyadobacter and Pseudomonadaceae which are known bioremediators of hydrocarbons. We hypothesise that a recorded short-term reduction in the soluble As concentration due to biochar amendment allowed native soil microbial communities to overcome As-related stress. We propose that increased microbiological activity (dehydrogenase activity) due to biochar amendment was responsible for enhanced degradation of organochlorines in the soil. Biochar therefore partially overcame the co-contaminant effect of As, allowing for enhanced natural attenuation of organochlorines in soil.
在一项为期180天的温室培养实验中，我们研究了生物炭对受有机氯和砷共同污染的历史悠久的羊浴液土壤中水溶性砷（As）浓度以及有机氯降解程度的影响。同时还调查了土壤微生物活性、细菌群落和结构多样性。由柳树原料（柳属植物）制成的生物炭在350或550°C下热解，并以10 g kg-1和20 g kg-1的速率添加到土壤中（分别相当于30 t ha-1和60 t ha-1）。六六六（HCH）的异构体α-HCH和γ-HCH（林丹）的浓度随着生物炭处理而分别降低了10倍和4倍。生物炭还导致土壤中滴滴涕（DDT）水平显著降低（P < 0.01），并提高了DDE:DDT的比例。与对照相比，在处理60天后，所有生物炭处理下的土壤微生物活性均显著增加（P < 0.01）。16S扩增子测序显示，添加生物炭的土壤中含有更多的金黄杆菌属、黄杆菌属（Flavobacterium）、双杆菌属（Dyadobacter）和假单胞菌科成员，这些都是已知的烃类生物修复菌。我们推测，生物炭改良导致可溶性砷浓度出现短期下降，使原生土壤微生物群落能够克服与砷相关的压力。我们提出，生物炭改良导致的微生物活性增加（脱氢酶活性）是土壤中有机氯降解增强的原因。因此，生物炭部分克服了砷的共同污染效应，使得土壤中有机氯的自然衰减得到增强。
