the sea the discharges standards (COD < 60 ppm) to the river are very strict. Petrochina implemented a maximum reuse strategy for wastewater up to 75% and a dedicated treatment for the removal of hard COD ... Reuse, Oxyblue, Densadeg, Biofor, Aquazur, Ozone, Industrial effluent treatment, Oil industry, Biofilters, Filters, Sand filtration, Reverse Osmosis, Oxidation, Desalination, Carbonate removal, Lime ... Reuse Oxyblue Densadeg Biofor Aquazur Ozone Industrial effluent treatment Oil industry Biofilters Filters Sand filtration Reverse Osmosis Oxidation Desalination Carbonate removal Lime...