Sulphur cycle is a sedimentary biogeochemical. Its reservoir is found on rocks and the earth's crust has potential for being bound under anaerobic conditions to cation like iron and calcium to form insoluble Fe (ferrous sulphide) ferric sulphur is released as sulphur dioxide (SO2 ) into atmosphere SO2 is released by burning of fossils fuel. Volcanic emission also causes addition of SO2 to atmosphere. SO2 of atmosphere is oxidised to SO3 which on combination with water form H2SO4 and reach on land as acid rain.