High rate aerobic treatment of synthetic wastewater using enhanced coagulation high-performance compact reactor (EC-HCR)

The high-performance compact reactor (HCR) is a type of JLR system for wastewater aerobic biological treatment processes. HCR has demonstrated outstanding performance with respect to space–time yield in more than 20 industrial applications, whereas, it has the disadvantage of cloudy effluent because of the disappearance of filamentous organisms in the HCR reactor. This study examined the potential of a new enhanced coagulation HCR (EC-HCR) system to improve the effluent quality of HCR. Results showed that, when 20–25 mg/L FeCl3 was added as coagulant into the coagulation tank, the effluent turbidity of EC-HCR system was lower. EC-HCR system could be operated at high organic loading and had high COD removal efficiency under short hydraulic retention time. When influent COD varied at 300–450 and 500–650 mg/L, there was no obvious difference on effluent COD compared with and without coagulant added. When influent with high COD concentration of 1000–1600 mg/L was treated, the COD removal efficiency could be improved obviously when 20 mg/L coagulant was added. There was no obvious difference between the nitrogen concentration in the effluent with and without coagulant, whereas, the phosphorus removal efficiency improved markedly when 20 mg/L coagulant was added into coagulation tank.