Irrigation with Coal Mining Effluents: Sustainability and Water Quality Considerations (São Pedro da Cova, North Portugal)

Water

João Ramalheira Rocha¹  Vítor Martins¹  Deolinda Flores²  Jorge Espinha Marques²  Patrícia Santos²  Joana Ribeiro²  Catarina Mansilha³  Armindo Melo³ 

[1] Department of Geosciences, Environment and Spatial Planning, University of Porto, 4169-007 Porto, Portugal;Institute of Earth Sciences, Porto Pole, University of Porto, 4169-007 Porto, Portugal;National Institute of Health Doutor Ricardo Jorge, Department of Environmental Health, University of Porto, 4050-083 Porto, Portugal;

关键词: coal mine wastewater quality;    irrigation;    heavy metals;    water quality index;    environmental impact;   

DOI  :  10.3390/w13162157

来源: DOAJ

【 摘 要 】

Two water effluents that drain from the abandoned coal mine of São Pedro da Cova (NW Portugal) were characterized in terms of their physic-chemical properties and suitability for irrigation purposes. Samples were also collected in a local surface stream, upstream and downstream from the mine drainage points, also used for irrigation by local farmers. Water samples were analyzed for major and minor ions and for trace element concentrations. Sampling campaigns started in 2017 and ended in 2019 and there were 46 water quality parameters tested. There were also proposed all-inclusive indices (the Water Quality Index and the Contamination Index, and also the Trace Element Toxicity Index) based on specific groups of 18 and 17 physic-chemical parameters, respectively, to achieve adequate monitoring requirements for mine effluents and surface water from coalfield. From the physical and chemical aspects of mine water it is inferred that the mine is not producing acid mine drainage. The coal mine water is of medium to high salinity, having almost neutral pH and a high thermal stability during the year, which is a distinguishing feature of the effluents. When compared to international irrigation water quality standards, as Food and Agriculture Organization of the United Nations admissible concentrations, the impacted waters are unsuitable for irrigation. The major outliers to the guidelines were iron, manganese, potassium, magnesium and bicarbonates, being also detected carcinogenic polycyclic aromatic hydrocarbons. Cost-effective ways of monitoring water quality parameters are needed to help control and manage the impact of coal mine effluents that should be treated before releasing into a ditch system that could be then used by local farmers to irrigate their crops.

【 授权许可】

Unknown