Some Chemical Considerations on the Distribution of Iron in the Sea

Abstract

A theoretical study of the behaviour of ferric phosphate in sea water has been made with existing data. The conditions least favourable for the continued existence of ferric phosphate should occur in the upper layers of the sea during active plant growth. The formation and stability of ferric phosphate is likely to be most favoured under the more acid conditions found in the gut of many animals. Ferric phosphate is likely to be introduced into sea water in animal faeces. Experimental confirmation of this deduction is essential.In all experimental work involving ferric phosphate in sea water, the need is indicated for very accurate control of hydroxyl-ion activity and probably pressure, and for attention to the time factor and to the physical condition of the precipitated phase. The topic is of geochemical as well as of biological interest.Dipyridyl is a reagent for ferrous iron. Reasons are set out why in sea and lake water at high dilutions it may also determine ferric iron without presence of an added reducing agent.Evidence is presented that ferrifluoride plays no part in the iron cycle in he sea.