Assessment of the Suitability of Mine Water Treated with Pervious Concrete for Irrigation Use

摘要

In water scarce countries, the treatment and re-use of polluted mine water can reduce water shortage problem. In this study, the possible use of pervious concrete to treat Acid Mine Drainage (AMD) for irrigation of agricultural crops, was investigated. Pervious concrete mixtures consisting of 6.7 mm granite aggregate and plain portland cement CEM I 52.5R with or without 30% fly ash were prepared and used to conduct column studies on AMD. The AMD types used in the study were obtained from abandoned coal (TDB) and gold (WZ) mines. Physico-chemical parameters of water including the pH, electrical conductivity (EC), Total Dissolved Solids (TDS), along with element concentrations were analysed. Also the Sodium Adsorption Ratio (SAR), Soluble Sodium Percentage (SSP), and Kelly's ratio (KR) of the treated AMD were calculated and compared against the water quality criteria for irrigation use. Results showed that treated TDB water was unsuitable for irrigation use owing to its high TDS, EC, SSP and KP values, even though its metal concentrations were reduced to satisfactory levels. Conversely, treated WZ water gave low SAR, SSP and KP indices, as well as satisfactory metal concentrations, indicating its suitability for use as irrigation water. The study shows that pervious concrete can be effective in treating AMD for irrigation use, but further research is needed to control high alkalinity and salinity levels in the treated water.