岩溶缺水地区集雨水箱水质指标的动态变化分析

Dynamic Change Analysis of Water Quality Index of Rainwater Harvesting Box in Karst Water Shortage Area

针对岩溶缺水地区集雨水箱材质的选取问题,开展了砖混、镀锌钢、高密度聚乙烯(HDPE)和线性低密度聚乙烯(LLDPE)材质的四种集雨水箱储水效果的实验研究。通过294天的现场记录,对水化学指标的变化进行了相关性分析,探究了造成水质变化的主导因素及其成因。实验结果表明:砖混水箱中雨水的水质受到水泥砂浆中的熟石灰和碱骨料反应的影响,并存在pH和铝离子超标的现象;镀锌钢水柜的水质会被镀锌层电化学反应影响,从而引起锌离子超标;HDPE和LLDPE水箱的水质受浮游藻类影响,其中,HDPE水柜易变形且存在富营养化,LLDPE水箱存在中营养化。在上述四种不同材质的水箱中,LLDPE水箱中雨水的水质情况最好,但仍存在中营养化的现象,建议采取避光措施或使用过滤装置,降低水体营养化程度后选用。通过研究岩溶缺水地区水箱材质对水质的影响,可为该地区水箱选材、有效利用水资源提供科学依据。

In view of the selection of rainwater harvesting tank materials in karst water shortage areas,experimental studies on water storage effects of four commonly used water tanks made of brick concrete,galvanized steel,high density polyethylene(HDPE)and linear low-densi⁃ty polyethylene(LLDPE)are carried out.Through the 294-day field record,the correlation analysis of changes in water chemical indexes is carried out,and the dominant factors and causes of water quality changes are explored.The experimental results show that the water quali⁃ty of brick mixing tank is affected by the reaction of lime and alkali aggregate in cement mortar,and there are phenomena of excessive pH and aluminum ions.The water quality of galvanized steel water tank will be affected by the electrochemical reaction of galvanized layer,re⁃sulting in the phenomenon of excessive zinc ions.The water quality of HDPE and LLDPE tanks is affected by planktonic algae.Among them,HDPE tank is prone to deformation and eutrophication,while LLDPE tank is mesotrophic.In the above four different materials of water tank,the water quality of rainwater in LLDPE water tank is the best,but there is still a phenomenon of medium nutrition.Taking light avoidance measures or using filtering devices are suggested to reduce the degree of water eutrophication.By studying the influence of tank material on water quality in karst water shortage area,this paper can provide a scientific basis for tank material selection and effective utilization of water resources.