Eutrophication decrease: Phosphates reduction in presence of nitrates by adsorption processes

Abstract

Eutrophication is a process in which a water body is enriched in soluble nutrients stimulating the aquatic growth resulting in the depletion of dissolved oxygen. This phenomenon causes aquatic environment degradation as well as serious problems for different purposes of waters use.Phosphorus and nitrogen, under mainly phosphate and nitrate chemical species, are considered responsible for eutrophication degradation. The main purpose of this research was to study, at laboratory scale, different processes based in on adsorption mechanisms for decreasing the concentration of phosphates in presence of nitrates in natural waters. The study was focused on dolomite (sedimentary rock), hydroxyapatite (bone meal) and slag as adsorbents. Dolomite and hydroxiapatite showed a high capacity for phosphate adsorption even in presence of nitrate. The results of the experiments with slag as adsorbent were low in terms of removal capacity and they not showed a clear trend.