小麦秸秆生物炭对土壤中Pb污染的钝化研究

STUDY ON PASSIVATION OF PB POLLUTION BY WHEAT STRAW BIOCHAR

为揭示小麦秸秆生物炭不同添加比例对土壤中重金属Pb的钝化影响,本文取云南国土资源职业学院校区酸性土壤,以质量比2%、5%和10%分别添加600℃下制备的小麦秸秆生物炭,并在培养10天、30天和50天后取样分析土壤pH值和重金属Pb四种形态变化。结果表明:在相同的培养时间,添加量越大,土壤pH值越大。土壤钝化时间越长,土壤中pH值也呈现逐渐增大的趋势。生物炭添加量对土壤中Pb的钝化影响较大,显示随着T600添加比例增加,土壤中重金属Pb可交换态、可氧化态和可还原态含量呈逐渐降低趋势,当添加量在10%,培养50d时,Pb残渣态最大达69.27%,钝化效果最好。

In order to reveal the effects of different addition ratios of wheat straw biochar on the passivation of heavy metal Pb in soil,wheat straw biochar prepared at 600 oC was addedto the acid soil of Yunnan Land Resources Vocational College at the mass ratio of 2%,5%and 10%,respectively.The pH value and four forms of heavy metal Pb of the soil were sampled and analyzed after 10,30 and 50 daysof incubation.The results show thatthe amount of biochar added has a great impact on the passivation of Pb in soil.The soil pH values increase with the addition of biocharat the same incubation time,or the increase of soil passivation time.The content of exchangeable,oxidizable and reducible form of heavy metal Pb in soil gradual decrease with the increase addition ratios of T600.The best passivation effect was obtained at 10%addition amount and 50 days of incubation,with the maximumof69.27mg/kg Pb ofresidue state.