A study, using a simulated sea-water, of the disposal of acidic iron effluent at sea

摘要

The titanium dioxide pigment industry at present disposesudof a large quantity of acid-iron waste by dumping it at sea. Theudensuing interactions result in a red discolouration of the environmentudwhich is a source of increasing public concern. A study hasudbeen made of the reactions that occur when an effluent solution ofudferrous sulphate in sulphuric acid is added to sea-water.udOn addition of the effluent solution there is an initialudrapid reaction between the effluent acid and the bicarbonate bufferudof sea-water. The ferrous iron content is dispersed, is subsequentlyudoxidised and precipitates as a form of ferric hydroxide. In seawaterudferrous iron solubility is controlled by the solubility ofudferrous carbonate. Solubility calculations, based on available thermodynamicuddata at 25 ° C, show that for the composition of typicaludindustrial effluents there is little possibility of ferrous carbonateudprecipitating on effluent dispersion in sea-water.