斯里兰卡CKDu病区地下水源饮用水关键问题及解决策略

Critical challenges and solutions on ground drinking water in chronic kidney disease of unknown etiology (CKDu) affected regions in Sri Lanka

不明原因肾病(CKDu)是斯里兰卡亟需解决的重要民生问题,其地下水源饮用水中的溶解性污染物可能是重要的致病原因。系统分析了北部中心省内高、低、非发病区及对照区(HR、LR、NR、CR)干湿季地下水的水化学特征和DOM特性,结果表明:地下水主要呈Ca-Mg-HCO3型,硬度和F-超标率较高,是地下水作为饮水安全保障最关键的指标;地下水中DOM主要为自生源,芳香性和腐熟化程度较低,主要为富里酸、腐殖酸和小分子蛋白质类物质;湿季DOM浓度较高,是Fe浓度增加的关键原因;而干季地下水中微生物活性较高,腐殖质和蛋白质发生分解,小分子络氨酸/赖氨酸的浓度增加。同时,发现不同区域地下水中DOM的生物利用性表现为HR<LR<NR<CR。其中,HR区地下水中的DOM最稳定,SUVA为(3.29±0.44)L·(mg·m)^-1,芳香性较高。有机无机的相互作用导致赋存形态、生物可利用性的变化可能是CKDu致病的重要原因。针对以上问题,提出"吸附-除F-软化-NF-消毒"的处理策略,通过有机物吸附处理、阴离子交换除F、软化除硬分离预处理及NF深度处理等技术有效解决地下水中DOM、F-、Ca^2+和Mg^2+超标的问题,实现饮用水的供给。本研究全面分析了CKDu病区地下水中的污染物组成,并提出解决策略,可为斯里兰卡饮用水安全保障提供支撑。

Chronic kidney disease of unknown etiology(CKDu)has been a key livelihood issue in Sri Lanka for years,and the dissolved contaminants in ground drinking water source was regarded as the main potential contributor.In this study,the hydrochemical characteristics and dissolved organic matters(DOM)properties of groundwater in several areas in Sri Lanka were investigated in terms of high,low,none CKDu prevalence(referred to as HR,LR,NR,respectively,hereafter),with a no CKDu areas set as control(CR).The investigated groundwater mainly exhibited a Ca-Mg-HCO3 type with high Ca^2+and Mg^2+,hardness,and F-,which were the main problems affecting safe water supply.The bio-availability of DOM showed a tendency of HR<LR<NR<CR,while DOM in HR also has highest aromaticity with a SUVA of(3.29±0.44)L·(mg·m)^-1.The DOM was main endogenous-sourced and showed low aromaticity and maturity,fulvic acid,humic acid,and protein were main components.DOM has high concentration in wet season,and Fe concentration increase.Bioactivity was higher in dry season,humics and proteins degradation happened and tyrosine and lysine presenting high concentration.No significant difference was found in DOM between CKDu related areas and control area,and it can be inferred that the interaction between inorganic and organic matters,which influence the speciation and bio-availability,can be the reason for CKDu.Adsorption-ion exchange-NF-disinfection coupled technology was designed for groundwater treatment for DOM,F and hardness control.This work systematically analyzed the water quality in CKDu region in Sri Lanka and offer an effective groundwater treatment strategy for safeguarding drinking water supply in Sri Lanka.