Recovery and characterization of struvite from sediment and sludge resulting from the process of acid whey electrocoagulation

Abstract

The whey produced in the cheese making in the dairy industry, is a residual high organic and rich in phosphorus. Electrocoagulation is an electrochemical process in which from compounds from the dissolution of an anode, is grouped and deposited the dissolved and colloidal organic matter (removal of COD) existing in a residual liquid, allowing its separation from water using conventional techniques. The objective of the present work has been to retrieve the contents of phosphorus in whey from sludge and sediment that are obtained from an electrocoagulation using aluminum anode, Ti/RuO2 cathode and applied voltage 3.67 ± 0.02 V under conditions optimized previously. Phosphorus was recovered as fertilizer (precipitation in form of struvite, MgNH 4PO4). Was removal the 86 % of COD, a recovery of 99.4 % of the phosphorus present in whey and sediment and 87.4 % was recovered from it in the form of struvite, which was identified and characterized by different instrumental analytical techniques.