Characteristics, Distribution, and Source Analysis of the Main Persistent Toxic Substances in Karst Groundwater at Jinan in North China

Abstract

Karst water in northern China is an important water source for economic and social development in its distribution area and water source for ecological function guarantee. With the enhancement of human activities, the water quality of karst water in the north has deteriorated and the bearing capacity of economic activities and social and ecological environment has weakened. The study on the distribution characteristics and source analysis of toxic substances in typical karst springs in northern China is of great practical significance for the sustainable development of karst areas in northern China. Based on the abundant karst water samples, the concentration, detection, and spatial distribution of toxic heavy metals and typical organic substances in karst waters were analyzed, the quality was evaluated, and the source of substances was analyzed. The results show that the toxic substances in karst water in Jinan are mainly distributed in the northern part of the Jinan urban karst water subsystem and Baiquan karst water subsystem in Jinan city, and the detection rate is low in other areas. The main distribution areas of toxic substances in karst water are the northeast and southwest parts of Jinan city. In the recharge area and runoff area of the karst spring area, the contribution rate of toxic substances to the comprehensive quality evaluation of karst water is relatively low and relatively high in the drainage area of the spring area. The organic index contributes more to the comprehensive quality evaluation of karst water. The distribution of toxic substances is related to the historical and current industrial layouts, and industrial discharge or leakage is the primary source of pollutants in karst water. The concentration of toxic substances in karst water has persistence and inheritance. This study enriches the research results on the distribution and sources of toxic substances in typical karst springs in northern China and provides essential data support for scientific understanding of the changes in karst water quality and optimization of water resource management in northern China.