Evaluation of Treatment Techniques for Utilising Acid Mine Water in Agriculture

Abstract

Acid mine water was treated with fly ash zeolite (FAZ), followed by different active chemicals to know its suitability for crops. Acid mine drainage (AMD) was obtained from Gorbi abandoned opencast mines of Singrauli, Northern Coalfields (NCL), India. The AMD was treated with 20 g/l dosing of fly ash zeolite, followed by different precipitating chemicals, using different doses of Ba(OH)2, BaCO3 and Ca(OH)2. The doses of 1.0 g/l Ba(OH)2, 1.5 g/l BaCO3 and 0.5 g/l Ca(OH)2 were used. The treatment with FAZ, followed by 1.0 g/l of Ba(OH)2, converted the water quality of AMD to the permissible level. The electrical conductivity (EC), percentage of sodium and metals found at the permissible level indicated the suitability of mine water for agriculture use. AMD treated directly with 1.0 g/l of Ba(OH)2 was found unsuitable for agriculture use. The treatment with FAZ and followed by BaCO3 (1.5 g/l) explained that the water quality was not at the permissible level and unsuitable for agriculture use. AMD treated directly with 1.5 g/l of BaCO3 was also found unsuitable for agriculture. The treatment with FAZ, and followed by 0.5 g/l dosing of Ca(OH)2, also showed water quality not at the permissible level. The conductivity, total salt content (as TDS) and sulfate values increased or decreased minimally, and there was an increase in the concentrations of total hardness and calcium hardness in the final treated mine water. The direct dosing with 0.5 g/l of Ca(OH)2 made AMD unsuitable for agriculture use. Treatment with 20 g/l FAZ followed by 1.0 g/l of Ba(OH)2 produced the treated AMD suitable for agriculture use.