摘要
为筛选出适宜镉砷污染土壤的复合钝化剂,采用D-最优混料设计方法,研究铁改性生物炭、酸改性海泡石和酸改性蛭石钝化土壤Cd和As的最优复配配方。结果表明:经FeCl3改性后的生物炭对As的吸附能力增加,对Cd的吸附能力降低;经酸改性后的海泡石和蛭石对Cd的吸附能力不变,对As的吸附能力增强。铁改性生物炭、酸改性海泡石和酸改性蛭石复配能有效降低土壤有效态Cd和As含量,活性态Cd主要向残渣态转化,活性态As主要向有机结合态和残渣态转化,Cd和As生物有效性降低。采用Design Expert统计软件分析数据,通过建立回归方程及多目标优化分析,获得复配钝化剂的配比为铁改性生物炭26.97%、酸改性海泡石23.49%和酸改性蛭石49.54%,经验证实验,施用优化配方后的土壤有效态Cd和As含量分别为0.97 mg·kg^-1和0.26 mg·kg^-1,与预测值接近。研究表明,铁改性生物炭、酸改性海泡石和酸改性蛭石复配能有效降低土壤Cd和As的生物有效性。
To select suitable amendments for soil polluted with cadmium and arsenic,the D-optimal mixture design method was used to find an optimum formula of modified biochar,sepiolite,and vermiculite for cadmium and arsenic stabilization.Compared to biochar,the capacity of FeCl3-modified biochar to absorb As increased but decreased for Cd.Compared to sepiolite or vermiculite,the capacity of acidmodified sepiolite or vermiculite to absorb As increased but remained unchanged for Cd.FeCl3-modified biochar combined with acid-modified sepiolite and acid-modified vermiculite could effectively reduce the content of Cd and As available in soil.The available Cd was transformed into a residual form whereas the available As was transformed into organic matter and residual forms.The statistical software Design Expert was used to analyze the data and a regression model was established for the available Cd and As parameters.Based on a complete consideration of these parameters,an optimal amendment formulation was found consisting of 26.97%FeCl3-modified biochar,23.49%acid-modified sepiolite,and 49.54%acid-modified vermiculite.When added amendments with the optimized formulation,the actual available Cd and As of soil were 0.97 mg·kg^-1 and 0.26 mg·kg^-1,respectively,which closely approximated their predicted counterparts.The results indicated that the combination of FeCl3-modified biochar and acid-modified sepiolite and vermiculite could effectively reduce the bioavailability of Cd and As in soil.
作者
熊静
郭丽莉
李书鹏
林启美
陈有鑑
XIONG Jing;GUO Li-li;LI Shu-peng;LIN Qi-mei;CHEN You-jian(National Engineering Laboratory for Site Remediation Technologies,Beijing 100015,China;College of Resources and Environmental Sciences,China Agricultural University,Beijing 100193,China)
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2019年第8期1909-1918,共10页
Journal of Agro-Environment Science
基金
国家重点研发计划项目(2017YFD0800900)~~
关键词
镉
砷
生物炭
海泡石
蛭石
最优配比
cadmium
arsenic
biochar
sepiolite
vermiculite
optimal formulation
