CAJ | 학술논문

2008年，昆明阳宗海受到严重砷污染，砷浓度高达0.134 mg／L。项目组充分考虑其受污染水体容量大、砷浓度低的实际情况，提出了安全、廉价、高效的FeCl3絮凝法治理方案。实验室小试结果表明，提出的FeCl3絮凝法对As （Ⅲ）及As（V）均有理想的去除效果，并且湖水中大量存在的阴离子HCO3－可使治理过程中水体pH值基本保持不变。因此该方案摒弃了文献普遍报道所需要的预氧化及调节pH值的工艺步骤，将固体FeCl3·6H2 O溶解、用湖水稀释后通过喷洒船将最终浓度为1％左右的FeCl3水溶液喷洒到湖面上，使湖水中的AsO3－4及AsO2－与FeCl3水解过程产生的Fe（OH）3胶体絮凝形成稳定的沉淀物被固定于底泥中。在对阳宗海进行降砷工程化治理期间，2009年11月—2010年9月砷浓度从0.117 mg／L快速下降到0.021 mg／L并可持续达到Ⅱ－Ⅲ类水标准（＜0.05 mg／L），总除砷率高达82.05％。沉积物中的As绝大部分以残渣态的形式被固定在沉积物中，生态风险很低。
2008년，곤명양종해수도엄중신오염，신농도고체0.134 mg／L。항목조충분고필기수오염수체용량대、신농도저적실제정황，제출료안전、렴개、고효적FeCl3서응법치리방안。실험실소시결과표명，제출적FeCl3서응법대As （Ⅲ）급As（V）균유이상적거제효과，병차호수중대량존재적음리자HCO3－가사치리과정중수체pH치기본보지불변。인차해방안병기료문헌보편보도소수요적예양화급조절pH치적공예보취，장고체FeCl3·6H2 O용해、용호수희석후통과분쇄선장최종농도위1％좌우적FeCl3수용액분쇄도호면상，사호수중적AsO3－4급AsO2－여FeCl3수해과정산생적Fe（OH）3효체서응형성은정적침정물피고정우저니중。재대양종해진행강신공정화치리기간，2009년11월—2010년9월신농도종0.117 mg／L쾌속하강도0.021 mg／L병가지속체도Ⅱ－Ⅲ류수표준（＜0.05 mg／L），총제신솔고체82.05％。침적물중적As절대부분이잔사태적형식피고정재침적물중，생태풍험흔저。
Yangzonghai Lake in Kunming was heavily polluted by arsenic with concentration up to 0.134 mg/L. Through taking full account of the large water storage capacity and the low arsenic concentration,a facile generic strategy of removal of arsenic by ferric salt was proposed.The strategy was of great advantage for high efficien-cy,low cost and ecological safety.Experiments in the laboratory scale demonstrated that FeCl3 coagulation can remove both As(Ⅲ)and As(Ⅴ)efficiently.Meanwhile,pH value of the water was kept constant after the co-agulation process.Therefore,the pretreatment operations of pre-oxidation and adjusting pH value,which were widely employed in literature,were omitted in the treatment engineering for arsenic contamination of Yangzong-hai Lake.Solid of FeCl3·6H2 O was dissolved and diluted to prepare FeCl3 solution with concentration of 1%FeCl3 ,which was sprayed into the lake.Colloid of Fe(OH)3 formed in the FeCl3 hydrolysis process would co-precipitate with ions of AsO3-4 and AsO2-in the lake and the stable precipitate was fixed in the sediment of the lake.During the treatment engineering for arsenic contamination of Yangzonghai Lake,the arsenic concentration was decreased from 0.1 17 mg/L to 0.021 mg/L in the period of November 2009 to September 2010.The con-centration of arsenic could be kept below the national standard of categoryⅡ-Ⅲ(<0.05 mg/L)and the re-moval ratio of arsenic was up to 82.05%.Residual fraction was the overwhelming arsenic form in the lake sedi-ment and its ecological risk was quite low due to its high stability.