Experimental Study on Domestic Sewage Treatment by An Internal-loop Air-lift Bioreactor
|Keywords||Inner loop Airlift Reactor Sewage Orthogonal Sludge characteristics|
Airlift circulating fluidized bed reactor based on traditional biological basis of a new aerobic biological treatment process, the reactor operation draws chemical state turbulent flow technology, sludge load, impact load ability, compact structure, small features of the ground. In this paper, the inner loop Airlift Reactor works are described, summed up the inner loop Airlift Reactor research status and in the sewage treatment industry applications. Test uses Airlift inner loop reactor treating domestic wastewater, the use of orthogonal experiment to determine the optimal parameters of the reactor, the reactor was studied for COD, NH4-N, SS, TN, TP and other major pollutant removal and impact on the load capacity of the reactor and activated sludge characteristics were studied. Experimental results show that: 1, through orthogonal experiment Airlift internal circulation reactor optimum operating parameters for the HRT10h, QL0.55m3 / h, SRT5d, the conditions stripper reactor effluent COD, NH4-N and SS The removal rates were 90.17%, 91.45% and 91.85%, and the effluent water meets \2, during the test, COD influent concentration minimum 229.71mg / L, max 595.69mg / L, the average concentration values ??375.71mg / L. Gas lift reactor maintained at 64.24-94.43% COD removal, the average removal rate was 81.24%. COD effluent concentration stable at 33.16-96.17mg / L, with an average effluent concentration was 63.24mg / L. Sludge load average 1.05kgCOD / (kgMLSS · d), higher than the general aerobic biological treatment process. 3, air-lift loop reactor within the SS removal efficiency remained at 87.72-93.35%, the average removal rate was 89.87%. By the orthogonal experimental results, the impact of gas stripping reactor effluent SS concentration of primary and secondary order SRT gt; QL gt; HRT, ie sludge age is the main influencing factors, followed by aeration, the impact is minimal hydraulic retention time. 4, the inner loop Airlift Reactor nitrogen and phosphorus removal capacity than normal biological treatment process. Reactor, TN, TP influent rate were 58.03-73.54mg / L and 5.34-19.19mg / L, the average TN removal rate of 55.61%, higher than the normal biological processes, 20% -40%, the average removal rate of TP 57.72%, higher than the normal biological processes 15% -20%. 5, the test methods by artificially adding sucrose investigate anti-stripping reactor water shock load capacity, results showed that the average gas lift reactor influent COD concentration was 707.56mg / L in the case, the effluent COD concentration was kept at 77.28-128.65 mg / L, average effluent concentration was 93.92mg / L, COD removal rate remained at 84.95-89.66%, the average removal rate was 86.11%. Visible, even influent COD concentration there was a substantial increase in gas lift reactor still maintained a high COD removal efficiency. 6, the air-lift loop reactor within the average between the SV and SVI were 15%, 93, was also found, SV curve and SVI similar trend curves, more obvious with time, indicating that the activity of the gas lift reactor sludge stabilization has also been strengthened.