Study On Chemical Fiber Wastewater Biotreatment With An Airlift Loop Reactor

In this paper, a 25L airlift loop reactor was applied to treat chemical fiber wastewater. The effect of airlift loop bioreactor on the chemical oxygen demand (COD) degrading process was investigated. The results indicated that a higher degrading rate and 93% COD removal efficiency could be obtained under the condition of room temperature, aeration of 0.325m³.h^-1, pH of 8.5⁹.0, HRT of 7.0h. The effect of adding different quantity of KH₂PO₄ on COD degrading rate was also investigated, the results showed that adding moderate KH2PO4 could increase COD degrading rate, the highest COD degrading rate can be obtained at the COD/P(mass ratio)of 200:1. In addition, the system ran continuously for thirty days under the optimum operation condition, when COD of the influent is 1000mg.L^-11400mg.L^-1, COD and NH₃-N of the effluent was lower than 100 mg.L^-1 and 10mg.L^-1, which were below the primary discharge standard for chemical fiber industry of China.Based on previous results, a novel airlift loop reactor by improving the general airlift loop reactor was developed. The new airlift loop reactor was applied to treat chemical fiber wastewater and the effect on airlift loop reactor in the chemical oxygen demand (COD) degrading process was investigated. The results indicated that a good COD degrading rate could be obtained under the condition of room temperature, aeration of 0.25m3.h^-1, pH of 8.5⁹.0, HRT of 9.0h, the circle wasteair influx of 0.16 m3.h^-1, and the alternation time of 2.0h , further more,the system ran continuously for thirty days under the optimum operation condition, when COD of the influent was 1900mg.L^-12200mg.L^-1, COD and NH₃-N of the effluent was lower than 100 mg.L^-1 and 10mg.L^-1, which were below the primary discharge standard for chemical fiber industry of China. At the same time, the kinetics of the COD degrading process is also studied in the paper, which is using the usual model of Monod model and Haldene model.The results of experiment incicated that the COD degrading process was according with Monod model, when the initial concentration of COD was 200¹250 mg.L^-1,MLSS of 1.10¹.50 g.L^-1; the COD degrading process was according with the Haldane model, when the initial concentration of COD was...