干旱半干旱地区农村窖水“熟化期”机理及水质安全保障技术研究

Cellar Rainwater is the only drinking water source in some northwest rural area.In order to solve the existing problems of drinking water, some rainwater collecting projects aiming at solving “the difficulty of drinking water for people” are conducted. They have solved the water shortage problem of this area, but water quality doesn’t meet the safe drinking standards ,and even produce toxic pollution problems.Farmers usually collect rainwater in the cellar in a few months to purify, that is commonly knew as “ripening”.Water quality has improved significantly after the ripening, but the mechanism of ripening is affected by factors such as the rainfall interval, the nature of collecting rainwater surface,cellar material,cellar mud characteristics, temperature and other factors, and the other for the extensive use of chemical fertilizers and pesticides,cellar water add a variety of Refractory organics, making the the water quality changes more complex and uncertain in "ripening period".Some areas of western rural areas are brackish water areas, complex soil salts permeate into the cellar rainwater, making the conventional treatment of cellar rainwater difficult to achieve water purification target.The aim of the project is to study the mechanism of "ripening period" of cellar rainwater and to explore the degradation and derivatization patterns of special pollutants in the "ripening period",so as to carry out technological innovation on the condition of studying the characteristics of the traditional cellar rainwater equipment in special areas,different pollutants.On the basis of cellar rainwater in the early research, to further improve the guarantee technology of the safety of water quality.The issue “the safety of drinking water for people” will be solved thoroughly in this area ,so that farmers drink assuring water.

在西北某些农村地区，窖水是唯一饮用水源。以“人饮解困”为目的的集雨工程，解决了饮用水量不足的问题,但水质并没有达到安全饮用标准,甚至产生毒害性污染问题。而农民净化水做法是将集雨水在水窖中封存几个月，俗称“熟化”。熟化后水质发生明显改善，但熟化的机理受降雨间期、集雨面性质、水窖材质、窖泥特性、温度等因素的影响，另因农村化肥农药大量使用、集雨窖水新增多种难降解有机物，使得“熟化期”内水质变化更具复杂性和不确定性。西部农村有些地区又属苦咸水地区，复杂的土壤盐分进入窖水，使得常规窖水处理难以达到水质净化目标。项目以集雨窖水“熟化期”为研究重点，深入研究“熟化期”机理问题，探索特殊污染物在“熟化期”内的降解和衍生规律，从而对传统窖水设备在特殊地区、不同污染物条件下进行技术革新，在前期窖水研究的基础上，进一步完善窖水水质安全保障适用技术，彻底解决窖水地区农村“人饮安全”问题，让农民吃上放心水。

西部干旱半干旱部分地区雨水为唯一饮用水水源，水质不符合《生活饮用水卫生标准》（GB5749-2006）要求，为有效地解决此类地区饮用水水质不达标的问题，本项目采用现场调研以及试验检测分析等综合手段，在对窖水水质进行长期监测的基础上，开展了集雨窖水水质特性、集雨窖水“熟化期”机理及水质安全保障技术的研究。结果表明：窖水在蓄积过程中水质变化经历了初期沉降、中间过渡和后期稳定三个阶段的“熟化”作用，水质类别主要以Ⅱ类和Ⅲ类为主，氮、磷为其主要特征污染。应用16S rRNA基因-高通量测序技术系统的研究了窖水中微生物功能基因和分类学多样性，以及窖水中细菌群落结构和功能在窖水存贮周期内的动态变化规律，得出水中微生物具有较高的分类学多样性，并构建了窖水细菌群落及其与水质因子在门、纲、目、科、属5个分类水平上的共现性关联网络，揭示了窖水中细菌群落及其与水质因子间复杂的交互作用关系和发挥的生态功能。在对集雨窖水“熟化期”水质特性和机理研究的基础上，针对苦咸窖水水质、集雨窖水中难降解有机物及抗生素降解，研究了国产纳滤膜对苦咸水中阴阳离子和氟离子的截留性能以及高级氧化降解水中抗生素的性能，研发了具有高效去除效果的超滤-强化混凝、超滤-预臭氧强化电絮凝、混凝-氯/紫外-纳滤组合工艺，并通过试验研究获得最佳工况参数，为西北干旱半干旱地区饮用水处理提供技术支撑。