Performance Of The Gaslift Self-Circulation (GSC) Reactor

The Gaslift Self-Circulation (GSC) reactor has been developed on the basis ofUASB reactor. The new reactor can create self-circulation of the liquid and has manyexcellent characteristics such as the ability to hold biomass, the capacity to undertakehigh volumetric loading rate, the stability to resist the shock load. During the studyfollowing results have been acchieved:1. The start-up of GSC reactor was finished within 63d, the maximum COD loadingrate was 18kg/L.d and the COD removal percentage was about 88%. Comparedwith the UASB (Upflow Anaerobic Sludge Bed) reactor and EGSB (ExpandedGranular Sludge Bed) reactor, the GSC reactor could increase volumetric CODloading rate more quickly and had a higher COD removal percentage.2. The potential of GSC reactor was tested. With COD removal percentage higherthan 80%, the volumetric COD loading rate could be raised to 24.49±0.36g/L.d,by increasing the intluent COD concentration. When the influent CODconcentration was 14.40g/L and HRT was 4h, the maximum volumetric CODremoval rate and biogas production rate were 21.31g/L.d and 10.13L/L.drespectively. The volumetric COD loading rate could be raised to 57.00g/L.d byshortening the HRT. When the influent COD concentration was 5.30 g/L and HRTwas 2.3h, the maximum volumetric COD removal rate and biogas production ratewere 48.15g/L.d and 10.13L/L.d respectively.3. The stability of GSC reactor was observed. The stability parameter under thesubstrate shock load were 2.46～3.04 and that under the hydraulic shock load was1.24～1.68. Their ratio was 1.55～2.04. The GSC reactor was able to tolerate thepH shock and recovered from the shock within 20h. The resistance of GSCreactor to pH shock was weaker than that to influent COD shock. Their ratio ofstability parameter was 1.11.4. The kinetic modles of substrate degradation and biogas production were set up as follows:The kinetic model of GSC reactor during loading testⅠwas1/X·dS/dt=1.20S_e/3.30+S_e, with V_maxⅠ=1.20d^-1, K_SⅠ= 3.30g/L. During loading testⅡ, itwas 1/X·dS/dt=30.1S_e/1.63+S_e, with V_maxⅡ= 3.01d^-1, K_SⅡ=1.63g/L. The average errorsof the two models were 6.71% and 13.80% when they were used for prediction.The biogas kinetic model during loading testⅠwas1/V·dG/dt=0.055dS/dt+0.016X, with Y_Ⅰ=0.055 gVSS/gCOD, b_Ⅰ= 0.016d^-1.During loading testⅡ, it was 1/V·dG/dt=0.033dS/dt+0.008X, with Y_Ⅰ=0.033 gVSS/gCOD, b_Ⅰ=0.008d^-1. The average errors of the two models were 2.21% and2.22% when they were used for prediction.