Water. desalination + reuse

PROJECTS Design Influent and Effluent Quality Table 1. Wastewater Quality from PTA & PET Devices Table 2. Wastewater Quality from PBT Device Table 3. Design Effluent and Brine Discharge Quality Description of the Treatment Process The challenge of this project is not only to treat wastewater from PTA production (which is highly polluted, about 10 times higher than domestic wastewater) according to the strictest Chinese wastewater discharge standard 1A, but also to produce process water from the treated wastewater to a quality better than drinking water. To do this, the top technology for wastewater treatment available on the market has to be installed, ranging from anaerobic treatment to various biological and chemical wastewater oxidation processes and filtration processes up to ultrafiltration (UF) and reverse-osmosis (RO) treatment. Added to this, the residual from the RO treatment, the brine waste stream, will be treated by a special process (oxidation and activated carbon filtration) so that it fulfills the Chinese discharge standard 1A for wastewater and can be discharged safely to the Jialing river. The treatment process includes: • Pretreatment Unit • Anaerobic Treatment Unit • Biological Treatment Unit • Advanced Treatment Unit • Reuse Water Treatment Unit • Brine Treatment Unit • Sludge Treatment • Odor Control Unit. Pretreatment unit mainly includes: PTA emergency tank, equalization tank, heat exchanger and PTA acidic sedimentation tank. PTA wastewater will be cooled down by heat exchange and sedimentated, then flows into the equalization tank together with the PET wastewater. The wastewater is fully mixed by a hydraulic mixer in the equalization tank, which can prevent suspended solids from settling, adjust water quantity and bring wastewater quality into line. If inflow quality (pH, chemical oxygen demand (COD)) changes a lot suddenly, wastewater should flow into the PTA emergency tank directly, then be pumped evenly into the equalization tank by a small-flow pump. Domestic wastewater and initial rainwater inside the industrial park first flow through the coarse screen to intercept large floating material, then flow into the distribution well of the second anoxic/aerobic (A/O) tank together with wastewater of other enterprises inside the industrial park. Circulating cooling wastewater flows into the circulating cooling wastewater tank by gravity and then is pumped into the distribution well of the second A/O tank. November-December 2013 | Desalination & Water Reuse | 23 |

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