屋面雨水回灌裂隙岩溶水水岩作用实验研究  

Laboratory experiment on water-rock interaction of the karst fracture water after recharged with roof rainwater

作　　者：朱中竹[1] 王维平[1] 蒋颖魁[1] 周亚群[1] 

机构地区：[1]济南大学资源与环境学院,山东济南250022

出　　处：《中国岩溶》2012年第3期272-278,共7页Carsologica Sinica

基　　金：国家自然科学基金项目--城市屋面雨水处理后回灌裂隙岩溶含水层试验研究(40972169)

摘　　要：在济南大学西校中采集奥陶系灰岩岩样,并设置不同的地下水、雨水混合比例进行室内溶蚀模拟实验。通过pH、电导率及几种常规离子的测定,并利用水文地球化学模拟软件PHREEQC等方法,分析雨水回灌含水层后与原有的地下水以及含水层介质之间的水—岩相互作用。结果表明:(1)地下水、雨水混合后,随振荡的持续进行,以及温度升高和脱碳酸作用的影响,水中CO2分压不断下降;(2)Ca2+浓度在混合比例为9∶1、7∶3和5∶5时略有下降,其它离子浓度无明显变化;(3)随雨水和岩溶系统作用时间的增加,方解石、白云石和石膏的饱和指数均不断减小,且随着雨水回灌量的增加,方解石、白云石饱和指数减小明显,从混合比例9∶1时的0.23～-0.39和0.05～-0.97到1∶9时的-0.34～-0.62和-1.59～-2.57,表明雨水能增强对方解石、白云石乃至整个含水层的溶蚀,且雨水回灌量越大,溶蚀作用越强烈,影响越明显;(4)雨水回灌所形成的溶蚀量比较有限,不会对回灌井周围含水层稳定产生严重影响。Simulation experiment is carried out to test the corrosive interaction between the Ordovician system limestone samples taken from the west campus of the Jinan University with the mixed water of different groundwater to rainwater ratio. The water-rock interaction among the original groundwater, aquifer media and rainwater being recharged is analyzed by means of determination of pH and electrical conductivity as well as several convention ions and using hydro-geochemical modeling software PHREEQC. The results show that , （1） after the groundwater and rainwater being mixed with each other, the CO2 pressure in the mixed water gradually decreases under the influence of temperature increase and decarbonation along with the oscil- lation （2） Ca^2＋ concentration slightly decreases when mixing ratios of groundwater and rainwater are 9 ： 1, 7 ： 3 and 5： 5 respectively, while other ions concentration does not change obviously; （3） saturation indexes of calcite, dolomite and gypsum decrease along with reaction time, and saturation indexes of calcite and dolomite decrease obviously along with the increases of recharging rainwater amount, from 0. 23 -0.39and 0.05 --0.97 when the ratio of groundwater to rainwater being 9 ：1 and from -0.34 -0.62 and -1.59 -2.57 when the ratio of groundwater to rainwater being 1 ： 9 respectively, which indicating that the rainwater is able to increase the corrosion to calcite and dolomite or even the whole aquifer and that the more the rainwater amount, the more obvious and stronger the corrosive effect; （4） rainwater recharge can only lead limited corrosion amount, so it won＇t cause obvious impact on the stability of the aquifers around the well.

关 键 词：雨水回灌 岩溶含水层 水岩作用 饱和指数 含水层稳定性 

分 类 号：P641.25[天文地球—地质矿产勘探]