生态环境学报
生態環境學報
생태배경학보
ECOLOGY AND ENVIRONMENT
2014年
10期
1691-1696
,共6页
曾祥峰%王祖伟%魏树和%于晓曼
曾祥峰%王祖偉%魏樹和%于曉曼
증상봉%왕조위%위수화%우효만
胡敏酸%镉%等温吸附%pH%无机盐
鬍敏痠%鎘%等溫吸附%pH%無機鹽
호민산%력%등온흡부%pH%무궤염
humic acid%cadmium%isotherm adsorption%pH%inorganic salts
为了探讨胡敏酸在碱性条件下的吸附镉机理，了解碱性盐化土壤中镉污染机理和生态环境之间的关系，实验研究了胡敏酸在碱性条件吸附镉的特征。采用批吸附试验方法，研究不同Cd初始浓度、反应时间、不同pH和离子强度对胡敏酸吸附镉的影响，结果表明：胡敏酸具有较强吸附镉的能力，可以用Langmuir吸附模型和Temkin吸附模型很好地拟合其等温吸附过程（r分别为0.9809和0.9816）；在60 min内的快速反应阶段和60 min至6 h间的慢速反应阶段，胡敏酸对镉的吸附量分别为2.895 mg·g-1和3.342 mg·g-1，吸附反应平衡前6 h的动力学过程可以用Elovich方程进行很好的拟合（r为0.9285）；随着pH增加，吸附率表现出逐步增加趋势，并以pH为4.5和8.5为界，呈现两端增加速度快，中间增加慢的规律性；在较低浓度离子强度下，离子强度的增加促进胡敏酸吸附镉；而在高离子强度下，表现出相反的规律性；在相同的条件下，不同离子强度对胡敏酸吸附镉的影响大小为：氯化钙>氯化镁>氯化钾>氯化钠。土壤在盐化的过程中，由于无机盐浓度的增加，增加了重金属离子的生物可利用性，加大了重金属离子的生态风险。
為瞭探討鬍敏痠在堿性條件下的吸附鎘機理，瞭解堿性鹽化土壤中鎘汙染機理和生態環境之間的關繫，實驗研究瞭鬍敏痠在堿性條件吸附鎘的特徵。採用批吸附試驗方法，研究不同Cd初始濃度、反應時間、不同pH和離子彊度對鬍敏痠吸附鎘的影響，結果錶明：鬍敏痠具有較彊吸附鎘的能力，可以用Langmuir吸附模型和Temkin吸附模型很好地擬閤其等溫吸附過程（r分彆為0.9809和0.9816）；在60 min內的快速反應階段和60 min至6 h間的慢速反應階段，鬍敏痠對鎘的吸附量分彆為2.895 mg·g-1和3.342 mg·g-1，吸附反應平衡前6 h的動力學過程可以用Elovich方程進行很好的擬閤（r為0.9285）；隨著pH增加，吸附率錶現齣逐步增加趨勢，併以pH為4.5和8.5為界，呈現兩耑增加速度快，中間增加慢的規律性；在較低濃度離子彊度下，離子彊度的增加促進鬍敏痠吸附鎘；而在高離子彊度下，錶現齣相反的規律性；在相同的條件下，不同離子彊度對鬍敏痠吸附鎘的影響大小為：氯化鈣>氯化鎂>氯化鉀>氯化鈉。土壤在鹽化的過程中，由于無機鹽濃度的增加，增加瞭重金屬離子的生物可利用性，加大瞭重金屬離子的生態風險。
위료탐토호민산재감성조건하적흡부력궤리，료해감성염화토양중력오염궤리화생태배경지간적관계，실험연구료호민산재감성조건흡부력적특정。채용비흡부시험방법，연구불동Cd초시농도、반응시간、불동pH화리자강도대호민산흡부력적영향，결과표명：호민산구유교강흡부력적능력，가이용Langmuir흡부모형화Temkin흡부모형흔호지의합기등온흡부과정（r분별위0.9809화0.9816）；재60 min내적쾌속반응계단화60 min지6 h간적만속반응계단，호민산대력적흡부량분별위2.895 mg·g-1화3.342 mg·g-1，흡부반응평형전6 h적동역학과정가이용Elovich방정진행흔호적의합（r위0.9285）；수착pH증가，흡부솔표현출축보증가추세，병이pH위4.5화8.5위계，정현량단증가속도쾌，중간증가만적규률성；재교저농도리자강도하，리자강도적증가촉진호민산흡부력；이재고리자강도하，표현출상반적규률성；재상동적조건하，불동리자강도대호민산흡부력적영향대소위：록화개>록화미>록화갑>록화납。토양재염화적과정중，유우무궤염농도적증가，증가료중금속리자적생물가이용성，가대료중금속리자적생태풍험。
In order to investigate the adsorption mechanism of cadmium on humic acid in alkaline condition and understand cadmium contamination mechanisms and its relationship with the ecological environment in alkaline saline soil, the adsorptions of cadmium on humic acid were studied by experiment in alkaline conditions. The different effect of initial concentration, reaction time, different pH and ionic strength on the adsorption of cadmium by humic acid were investigated though batch adsorption test methods. The results indicated that, humic acid had strong cadmiumadsorption ability. Langmuir and Temkin adsorption models were well fitted isotherm adsorption process (r are 0.9809 and 0.9816). The adsorption capacities at the rapid response period within 60 minutes and the slow reaction within 60minutes to 6 hours, are 2.895 mg·g-1 and 3.342 mg·g-1, respectively. The process before the adsorption reaction reached equilibrium state can be well described by the Elovich equation (r = 0.9285). As the pH increased, the adsorption rate showed a gradual increasing trend, and had two boundaries at pH 4.5 and 8.5, respectively. In low ionic concentration, ionic strength can be increased to promote cadmium adsorption on humic acid. However, the opposite regularity was represented in high ionic concentration. Under the same test conditions, the different ionic strengths affect the abilities of humic acid adsorption of cadmium as follow: calcium chloride>magnesium chloride>potassium chloride> sodium chloride. The bioavailability and the ecological risk of heavy metals are increased during the soil salinization process, due to the increase in salt concentration.
