- 期刊
- OpenAccess
Heavy Metal Contaminated Soil and Sediment of Abandoned Sulfide Mines as A Source of Environmental Contamination: A Case Study of Minh Quang Pyrite Mine, Ba Vi, Hanoi, Vietnam
以廢棄硫化物礦山的重金屬污染土壤和沈積物作為環境污染源－以越南河內巴維明光黃鐵礦山為例
摘要
In despite that pyrite mines which were extensively exploited during the 1970-1990 years had ceased for more than 24 years, there are still occurring acid-drainage-related impacts on the ecology. Minh Quang abandoned pyrite mine area is an example of an environmental "hot spot", which is located just in the buffer zone of Ba Vi national park. Besides the measuring pH of the stream water at 26 points at the end of the dry season and in the rainy season in 2022 along the mine's stream and Minh Quang stream, the stream water samples, soil water samples, soil and sediment samples were collected for heavy metal analysis and evaluation for the possible environmental contamination effect. The soil of the mine's waste dump has high concentrations of Cd, Pb, Cu, and Ni and may serve as a heavy metal contaminant source, although the soil is classified as a deficiency to moderate heavy metal enrichment. The area of the waste dump is about 7,700 m^2 with an average thickness of 1.8 m and contains about 14,000 m^3 of contaminated soil or about 20,000 tons of dry contaminated soil. Besides the contaminated soil of the waste dump, the mine's stream contains contaminated sediment by Pb and Ni, while the sediment is classified as a deficiency to moderate enrichment by all the analyzed heavy metals, i.e., Cd, Pb, Cr, Cu, Zn, and Ni. Besides the possible contamination of the land due to the soil and sediment's high heavy metal concentrations, the soil water with extremely high concentrations of heavy metals would cause the below groundwater contaminated by heavy metals. The abandoned Minh Quang pyrite mine and its waste dump in particular and others in general are worthwhile to be strictly considered as a growing awareness of geo-environmental hazards that need to be taken into serious consideration of remediation as soon as possible to cease the soil, surface and groundwater contamination by heavy metals as man-made disasters' consequences. Before future remediation action, an isolation of the waste dump area needs to be constructed as soon as possible to stop heavy metal from spreading to the downstream land and streams.