title: Use of organic substrates as electron donors for biological sulfate reduction in gypsiferous mine soils from Nakhon Si Thammarat (Thailand).
abstract: Soils in some mining areas contain a high gypsum content, which can give adverse effects to the environment and may cause many cultivation problems, such as a low water retention capacity and low fertility. The quality of such mine soils can be improved by reducing the soil's gypsum content. This study aims to develop an appropriate in situ bioremediation technology for abbreviating the gypsum content of mine soils by using sulfate reducing bacteria (SRB). The technology was applied to a mine soil from a gypsum mine in the southern part of Thailand which contains a high sulfate content (150 g kg(-1)). Cheap organic substrates with low or no cost, such as rice husk, pig farm wastewater treatment sludge and coconut husk chips were mixed (60:20:20 by volume) and supplied to the soil as electron donors for the SRB. The highest sulfate removal efficiency of 59% was achieved in the soil mixed with 40% organic mixture, corresponding to a reduction of the soil gypsum content from 25% to 7.5%. For economic gains, this treated soil can be further used for agriculture and the produced sulfide can be recovered as the fertilizer elemental sulfur.
authors: Pollution Prevention and Resource Recovery Chair Group, UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft, The Netherlands. Electronic address: som_cheng00@hotmail.com.
authors: Pimluck
authors: P
authors: Kijjanapanich
authors: Environmental Engineering and Management, Asian Institute of Technology, PO Box 4, Klongluang, Pathumthani 12120, Thailand.
authors: Ajit P
authors: AP
authors: Annachhatre
authors: Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Via Di Biasio 43, 03043 Cassino, FR, Italy.
authors: Giovanni
authors: G
authors: Esposito
authors: Pollution Prevention and Resource Recovery Chair Group, UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft, The Netherlands.
authors: Piet N L
authors: PN
authors: Lens
mesh_terms: D000383:Agriculture; D001419:Bacteria / Q000378:metabolism; D001673:Biodegradation, Environmental; D019149:Bioreactors; D002133:Calcium Sulfate / Q000737:chemistry*; D004583:Electrons; D005308:Fertilizers; D008906:Mining; D012275:Oryza; D010084:Oxidation-Reduction; D012722:Sewage / Q000737:chemistry; D012987:Soil / Q000737:chemistry; D013431:Sulfates / Q000737:chemistry* / Q000378:metabolism; D013785:Thailand
chemical_list: D005308:Fertilizers; D012722:Sewage; D012987:Soil; D013431:Sulfates; D002133:Calcium Sulfate
keywords: Gypsiferous soil; Gypsum mine; Mixed organic substrate; Overburden; Solid sulfate; Sulfate reduction