天津市地下水氟含量分布规律及形成机理探究.docVIP

天津市地下水氟含量分布规律及形成机理探究摘要：天津市浅层地下水氟含量的分布大致以咸淡水分界线为界，界线以南绝大多数地区地下水氟含量小于1.0 mg/L，而分界线以北存在着高氟地下水，其中侯家营至青甸洼一带，氟含量已超过4.0 mg/L；深层地下水氟含量大部分地区超过1.0 mg/L，呈现北部、东北部含量较低、南部含量较高的特点；武清区中部及东南部、静海县大部、市区及郊区、大港区氟含量均在2.0 mg/L，东丽区大部和塘沽区为本市深层地下水氟高值区，其含量多在4.0 mg/L以上。本市地下水氟含量形成机理主要与地下水赋存的地质构造、地质环境、水文地质化学特征、径流条件等因素有关，土壤和地层岩石中氟矿物含量、化学成分、地下水环境的酸碱度、矿化度、水温等均为地下水氟含量的重要影响因素。 Distribution and Formation Mechanism of Fluorine Content in Groundwater in Tianjin, China Abstract：The fluorine concentration distribution in Tianjin superficial aquifer groundwater is divided as that of saline water and fresh water dividing line. The fluorine concentration is lower than 1.0 mg/L in the south of the line, but it is higher in the north of the line. The fluorine concentration in superficial aquifer groundwater is higher than 4.0 mg/L in Hou Jia-ying and Qing Dian-wa line. The fluorine concentration in deeper groundwater is higher than 1.0 mg/L in main area, and it is lower in the north and north-east, higher in the south. It is about 2.0 mg/L in the center area and south-east of Wu Qing district, most area of Jing Hai district, downtown area and suburb area and Da Gang district. The higher value area of fluorine concentration is in Dong Li district and Tang Gu district, which is higher than 4.0 mg/L. The mechanism of fluorine formation in groundwater has relationship with geological structure, geological environment, hydrological geology and runoff. The main influence indicators of fluorine concentration in groundwater are the fluorine content in mineral in the soil and stratum, chemical component, groundwater pH value, mineralization and groundwater temperature, etc. 氟是人体的必需元素，它对人体健康的影响，随着摄入量而变化。适量氟有利于人体健康，适宜范围为0.5～1.1 mg/L。当氟摄入量少而缺乏时， 则引起龋齿及骨质疏松，老年人导致骨折；摄入过量则导致氟中毒，主要表现为氟斑牙和氟骨症。研究表明，地氟病主要由地质环境中特别是地下水中氟含量较高所致，氟病区的分布往往与高氟地下水的分布一致。天津市城郊广大居民9a5%以上依靠开采地下水作为其生活饮用水，据有关资料表明，目前天津市患氟中毒症病人达310余万人，其中120万人患有氟斑牙，约3万人患氟骨症[1]。 一、浅层地下水氟含量分布规律及形成机理 1.浅层地下水矿化度及氟含量分布 本市浅层地下水矿化度由北向南和东南，即由山前平原向滨海平原，呈逐渐增高的规律，北部山前倾