A laboratory study of the immobilisation of cadmium in soils

Environmental Pollution Series B, Chemical and Physical Pub Date : 1986-01-01 DOI:10.1016/0143-148X(86)90015-7

Tao Zhan

{"title":"A laboratory study of the immobilisation of cadmium in soils","authors":"Tao Zhan","doi":"10.1016/0143-148X(86)90015-7","DOIUrl":null,"url":null,"abstract":"<div>Traces of cadmium ion in solution, alone and together with different cadmium bonding agents (K2CO3, CaCO3, KH2PO4, Ca3(PO)4, Fe(NO3)3 and Fe(OH)3), were added to three soils of pH 5·0, 7·0 and 7·6, respectively, and incubated aerobically at 45°C for 6 days.The extent to which the different binding agents immobilised cadmium in the treated soils was determined by measuring the amounts extracted by CH3COONH4, CaCl2, NH4Cl, Ca(NO3)2, (CH3COO)2Ca or KNO3 solutions. The extracted cadmium was determined by AAS. Recoveries by the different extractants, which are representative of those proposed for the determination of ‘available cadmium’ in soils, showed a systematic variation for each of the treated soils. The extent to which these differences arise from pH and the complexation of the cadmium is discussed.Markedly different amounts of cadmium were immobilised in the different soils, under the same conditions and treatments. CaCO3 and Ca3(PO4)2 were the most efficient in immobilising cadmium in the acid soil, K2CO3 and Ca3(PO4)2 were best with the neutral soil and Fe(NO3)3, Fe(OH)3 and Ca3(PO4)2 with the calcareous soil. Thus, under the aerobic conditions likely to be found in dry farmlands, the cadmium immobilisation mechanisms appear to be associated with precipitation on carbonate and phosphate surfaces; in calcareous soils, the surface hydrolysis of cadmium on ferric hydroxide seems most important.</div>","PeriodicalId":100484,"journal":{"name":"Environmental Pollution Series B, Chemical and Physical","volume":"12 4","pages":"Pages 265-280"},"PeriodicalIF":0.0000,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0143-148X(86)90015-7","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Environmental Pollution Series B, Chemical and Physical","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/0143148X86900157","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}

引用次数: 0

Abstract

Traces of cadmium ion in solution, alone and together with different cadmium bonding agents (K₂CO₃, CaCO₃, KH₂PO₄, Ca₃(PO)₄, Fe(NO₃)₃ and Fe(OH)₃), were added to three soils of pH 5·0, 7·0 and 7·6, respectively, and incubated aerobically at 45°C for 6 days.

The extent to which the different binding agents immobilised cadmium in the treated soils was determined by measuring the amounts extracted by CH₃COONH₄, CaCl₂, NH₄Cl, Ca(NO₃)₂, (CH₃COO)₂Ca or KNO₃ solutions. The extracted cadmium was determined by AAS. Recoveries by the different extractants, which are representative of those proposed for the determination of ‘available cadmium’ in soils, showed a systematic variation for each of the treated soils. The extent to which these differences arise from pH and the complexation of the cadmium is discussed.

Markedly different amounts of cadmium were immobilised in the different soils, under the same conditions and treatments. CaCO₃ and Ca₃(PO₄)₂ were the most efficient in immobilising cadmium in the acid soil, K₂CO₃ and Ca₃(PO₄)₂ were best with the neutral soil and Fe(NO₃)₃, Fe(OH)₃ and Ca₃(PO₄)₂ with the calcareous soil. Thus, under the aerobic conditions likely to be found in dry farmlands, the cadmium immobilisation mechanisms appear to be associated with precipitation on carbonate and phosphate surfaces; in calcareous soils, the surface hydrolysis of cadmium on ferric hydroxide seems most important.

查看原文

微信好友朋友圈 QQ好友复制链接

本刊更多论文

镉在土壤中固定化的实验室研究

在pH分别为5.0、7.0、7.6的3种土壤中分别加入微量镉离子溶液和不同镉结合剂(K2CO3、CaCO3、KH2PO4、Ca3(PO)4、Fe(NO3)3和Fe(OH)3)， 45℃好氧培养6 d。通过测量CH3COONH4、CaCl2、NH4Cl、Ca(NO3)2、(CH3COO)2Ca或KNO3溶液的萃取量，确定了不同结合剂在处理土壤中固定镉的程度。用原子吸收光谱法测定提取的镉。不同萃取剂的回收率是测定土壤中“有效镉”的代表性萃取剂，在每种处理过的土壤中显示出系统的差异。讨论了这些差异在多大程度上是由pH和镉的络合作用引起的。在相同的条件和处理下，不同土壤中镉的固定量明显不同。在酸性土壤中，CaCO3和Ca3(PO4)2对镉的固定效果最好，K2CO3和Ca3(PO4)2在中性土壤中固定效果最好，Fe(NO3)3、Fe(OH)3和Ca3(PO4)2在钙质土壤中固定效果最好。因此，在干旱农田中可能发现的有氧条件下，镉的固定机制似乎与碳酸盐和磷酸盐表面的降水有关;在钙质土壤中，镉在氢氧化铁上的表面水解似乎是最重要的。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文去求助