老化过程对生物质炭吸附-解吸附邻苯二甲酸二乙酯的影响

Effect of different aging processes on the adsorption and desorption of diethyl phthalate to soil amended with biochars

将稻草和竹锯末在500℃条件下炭化制备得到两种生物质炭,并与土壤充分混合老化处理30 d.通过批处理恒温振荡法,研究了老化过程(恒湿和干湿交替)、制备原材料、不同施用量(0、0.1%和0.5%,质量分数)和土壤类型(熟化红壤、新垦红壤)对生物质炭吸附邻苯二甲酸二乙酯(DEP)的影响.结果表明,土壤中添加生物质炭的处理对DEP的吸附能力显著增强,且随着生物质炭添加量的增加,各个处理对DEP的吸附能力增强.与稻草炭相比,竹炭对DEP具有更强的吸附能力并且更难以解吸附DEP.与添加新鲜生物质炭的土壤相比,老化过程降低了加炭处理对DEP的吸附能力.不同老化条件下,生物质炭吸附DEP能力的降低顺序也不同,主要表现为:干湿交替>恒湿.

Biochars derived from bamboo sawdust （BB） and rice straw （SB） were prepared by pyrolysis at 500 ℃. Soils mixed with biochars were incubated for 30 d of aging. A batch equilibration method was used to evaluate the effect of aging processes （alternating wet and dry, and constantly moist）, feedstock materials and biochar usage （0,0.1% and 0.5%, w/w） on the adsorption and desorption of diethyl phthalate （DEP） in two vegetable garden soils. The results indicate that biochar amendment significantly enhanced the adsorption of DEP for each treatment and the sorption of DEP increased with increasing usage of biochar. Bamboo biochar were more effective than the straw biochar in improving soils＇ adsorption capacity and reducing the desorption ability of DEP. Compared with soils amended with fresh biochar treatments, aging treatment reduced the DEP adsorption capacity of the biocbar-treated soils. As for different aging conditions, the reduction of adsorption capacity of biochar treated and untreated soils were greater in the alternating wet and dry treatment than in the constantly moist treatment.