Classification of Groundwater Contamination in Yuxi River Valley, Shaanxi Province, China

摘要

This study investigated groundwater contamination in the Yuxi River Valley in northern Shaanxi Province, one of largest energy resource centers in China. Groundwater samples collected from 129 locations in the Yuxi River Valley area were analyzed and evaluated to establish the local groundwater quality zonings. Results indicate that groundwater in the Yuxi River Valley is contaminated, and the dominant contaminants in the groundwater are ammonium (NH₄ +) and nitrite (NO₂ −). Maximal concentration of NH₄ + was detected at 0.019 and 3.50 mg/L in the samples collected up-gradient and down-gradient, respectively, of the segment of Yuxi River that flows through Yulin City. Concentration of NO₂ − was detected at 0.0015 and 1.522 mg/L, respectively from the same samples. Zones I through IV, from non-polluted to seriously polluted, were identified for groundwater quality in the Yuxi River Valley. We attribute the groundwater contamination in the Yuxi River valley to sources in the Yulin township, presumably its wastewater discharge. Keywords Groundwater contamination - Nitrite - Shaanxi - Yulin - Yuxi River Valley