Microplastics Removal Efficiency and Risk Analysis of Wastewater Treatment Plants in Oman

This study aimed to assess the MPs load of three wastewater treatment facilities in Oman using various treatments, including MBR, SBR, and CAS. Wastewater samples from influent, effluent, and sludge were collected and analyzed to determine the concentration, morphology, size, color, and polymer type of the MPs. A set of sieves with a mesh size range of 1 mm to 45 μm was used to for filteration. Oxidation treatment was applied for all samples using Fenton's reagent, followed by density separation by sodium chloride solution. The Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR- FTIR) method was utilized to test 10% from each sampling point to confirm the polymer types of the MPs. The pollution load index (PLI) and hazard index (HI) have been employed to assess the risk associated with the chemical toxicity and concentration of detected particles. The PROMETHEE method was used to rank the risk of sampling sites based on different criteria that posed potential ecological and human health risks. The results indicate that the average concentrations of 0.99 MPs/L, 1.38 MPs/L, and 0.93 MPs/L were detected in the final treated effluent of WWTP A, WWTP B, and WWTP C, respectively. These concentrations correspond to overall removal efficiencies of 82.5%, 77.4%, and 79.2% for WWTP A, WWTP B, and WWTP C, respectively Most MPs found in tertiary effluent were smaller particles (425μm) and fiber-shaped. The major types of MPs were polypropylene (PP), low-density p...
Source: Chemosphere - Category: Chemistry Authors: Source Type: research