摘要
添加Fe S、电石渣、菌渣复配材料稳定处理砷污染土壤,采用国标硫酸-硝酸法(SNP)和美国毒性浸出程序(TCLP)检测处理前后污染土壤砷的浸出浓度,依据浸出浓度评价稳定效果,并探讨土壤含水量、土壤pH、竞争性离子、反应时间、污染初始浓度对砷稳定效果的影响。结果表明:(1)SNP法和TCLP法浸提土壤,砷的浸出浓度为污染原土>对照处理>>稳定处理,稳定处理有效降低砷的浸出毒性。(2)砷的稳定效果影响因素研究表明,土壤含水率以30%为宜;土壤pH于2.20~9.85时砷的稳定效果良好,且pH=6.05时最佳,pH高于9.85至12.01时稳定效果减弱;竞争性离子对土壤砷稳定效果的抑制作用表现为PO_4^(3-)垌SO_4^(2-)≈NO_3^->Cl^-;土壤砷的稳定效率随反应时间先上升后平缓,于15 d后趋于稳定并持续至120 d;土壤中砷的污染初始浓度为506 mg kg^(-1)、833 mg kg^(-1)、2951 mg kg^(-1)和5290 mg kg^(-1),砷的稳定效率分别为92.36%、90.53%、55.57%和47.54%,稳定效率随着污染初始浓度升高而降低,稳定药剂适用于一定污染浓度范围。
Composite stabilizing reagents containing FeS, carbide slags, and mushroom wastes were utilized to immobilize arsenic in the contaminated soil. Two methods of SNP （solid waste - extraction procedure for leaching toxicity - sulphuric acid ＆ nitric acid method） and TCLP （toxicity characteristic leaching procedure） were used to evaluate the leaching toxicity of arsenic. The results showed that leaching amounts followed the order of contaminated original soil 〉 control treatment 〉〉 stabilization treatment and stabilization treatment effectively reduced the arsenic leaching toxicity. The stabilization efficiency was best at soil moisture content of 30% and soil pH of 6.05. The effect of inhibition of four competitive ions on arsenic stabilization ranked in the order of PO4^3- 〉〉 SO4^2- ≈ NO3^- 〉 Cl^-. Meanwhile, time also had certain effect on the stabilization efficiency. Moreover, the initial concentrations of arsenic in soil were 506 mg kg^-1, 833 mg kg^-1, 2951 mg kg^-1 and 5290 mg kg^-1, respectively, and their stability efficiencies of arsenic were 92.36%, 90.53%, 55.57% and 47.54%, respectively. The stabilization efficiency decreased with the increase of the initial concentration of pollution, and the stabilizing reagent could be suitable only for a certain range of arsenic concentration.
出处
《土壤通报》
CAS
北大核心
2017年第1期208-213,共6页
Chinese Journal of Soil Science
基金
广西高校科学技术研究项目一般项目(2013YB258)
广西高校化学工艺重点学科基金(2015KLOG15)资助
关键词
土壤
复合材料
浸出毒性
稳定效率
影响因素
Soil
Composite material
Leaching toxicity
Stabilization efficiency
Influence factors
