Petrochemical waste characterization and management at Pars Special Economic Energy Zone in the south of Iran.

Industrial waste management generated by different petrochemical complexes at Pars Special Economic Energy Zone, located in the south of Iran, was investigated. All 10 active petrochemical complexes were visited and generated wastes were identified by a checklist. Petrochemical plants were classified regarding feeds, process, and products and nine representative wastes were sampled. Physicochemical characteristics were analyzed and appropriate management approaches were proposed according to the literature review and the results of waste characterization. The generated wastes were classified as hazardous and non-hazardous according to the Basel Convention and Environmental Protection Agency lists of waste classification. Also, the concentrations of organic compounds and heavy metals were measured to classify wastes characteristically. Comparing concentrations of the most important heavy metals in sampled wastes illustrated that sandblast with Cu concentration of 4295 mg kg-1, spent activated carbon with Hg concentration of 127 mg kg-1, and spent catalyst with 25% Ni content can be categorized as hazardous wastes, due to the exceeding Total Threshold Limit Concentration levels. Based on laboratory results, all industrial waste generated in the petrochemical complexes were categorized into three groups, namely Organic Waste with High Calorific Value, Non-organic Recyclable Waste, and Non-organic Non-recyclable Waste. Finally, management approaches, including material recycling, energy recovery (through incineration), and landfilling, were proposed and a conceptual model was suggested in order to show different routes and final destination for each kind of waste generated in all similar petrochemical complexes.

Novel antifouling and antibacterial polyethersulfone membrane prepared by embedding nitrogen-doped carbon dots for efficient salt and dye rejection.

Novel antifouling and antibacterial nanofiltration membranes were prepared by addition of nitrogen-doped carbon dots (NCDs) to the polyethersulfone (PES). The antibacterial NCDs were successfully fabricated using hydrothermal technique and then were characterized using photoluminescence (PL) spectra, FTIR, XRD, and dynamic light scattering (DLS). The resulted nanoparticles were introduced to PES through the phase separation method. The effect of adding NCDs into the PES membrane, as a novel nanofiller was studied in terms of surface and cross-sectional morphology, hydrophilicity, porosity, permeation, fouling resistance, antibacterial properties, and nanofiltration performance. All the NCD-blended membranes exhibited better performance compared to the bare PES. The water flux was significantly increased from 16.5 kg/m2h for the bare PES to 44.6 kg/m2h for the 0.50 wt% NCD-blended membrane. The 0.50 wt% of NCD-blended PES membrane also showed the best antifouling properties, with a flux recovery ratio (FRR) of 73.1%. The retention sequence of the salts was Na2SO4 (80.3%) > MgSO4 (63.5%) > NaCl (20.7%), showing the common behavior of the negative charge nanofiltration membranes. The antibacterial assessment showed a zone of inhibition for both Gram-negative and Gram-positive bacteria in disks membranes containing higher than 0.10 wt% of NCD concentrations. The results offer NCD-blended membranes as a high potential hydrophilic and antibacterial nanofillers.