Pilot-Scale Study on Treating Wastewater from Magnesium-Based Exhaust Gas Cleaning System by a Novel Process

Abstract

According to our previous results on the magnesium-based exhaust gas cleaning system (Mg-EGCS), certain parameters of the desulphurization wastewater (such as chemical oxygen demand (COD), suspended solids (SS), total oil content and turbidity) were above the washwater discharge criteria set by the International Maritime Organization (IMO). In this work, a novel combined process of aeration-centrifugation and filter pressing was proposed, and a pilot-scale experiment was carried out to treat the desulphurization wastewater. The results demonstrated that the quality of wastewater treated by the combined process could meet the IMO’s washwater discharge standard, with COD of 115 mg/L, SS of <5 mg/L, polycyclic aromatic hydrocarbons (PAHs) of <1 μg/L, and total oil content of 5.1 mg/L, when the washwater flow rate was 0.45 m3/h.