Contrasting behaviour of arsenic, iron, manganese and uranium during anaerobic incubation of aquifer sediments from Nadia, West Bengal by Press, L, Gault, A, Mondal, D, Lythgoe, P, De Hoog, J, Heimann, A, Lawson, M, Hery, M, Van Dongen, B, Porcelli, D, Lloyd, J, Pancost, R, Polya, D