Study On Treatment Of Wastewater By Biological Active Carbon Fluid Bed

In this paper,both physics and biological function for Synthetic organic wastewater removal were studied in fluid bed reactor using granular active carbon as carrier.a sorption equation and dynamic parameter of substrate degradation and sludge growth were obtained, It provided technical parameters for industrialization of the process. The results were shown as following:1. After 60 minutes, 65.08% of COD removal rate and 6.8.75% of ammonia nitrogen removal rate were achieved through adsorption of active carbon when the COD and ammonia nitrogen concentration of the raw water were 128 mg/L and 6.4 mg/L.2. The adsorption isotherm can be described by Freundlich equation (R² were 0.9918 and 0.976) , Which were q= 10.41C^0.434,q=2.13C^0.453 and 1/n was between 0.1 and 0.5.3. Under the condition that pH was 6.2～7.5 and DO was 3.8～4.2 mg/L, the COD removal rate were 81.25%,83.75%,78.79%,75.63% respectively, the ammonia nitrogen removal rate were 89.24%,91.85%,94.53 %,82.76% respectively, and the average biology film thickness were 80μm,105μm,175μm,275μm when the average concentration of raw water were 32 mg/L,64 mg/L,128 mg/L,320 mg/L respectively. The best removal concentration of raw water was 64 mg/L. the reactor has strong amortized ability to pollution load, and the microorganism adaptability was strong.4. Under the condition that when the concentration of COD and NH₄⁺-N was 64 mg /L and 3.2 mg /L, pH was 6.2～7.5, temperature was 22～26℃and DO was 3.8～4.2 mg /L, the COD removal rate reached 75.31%,81.72%,84.02%,80.78% respectively, the ammonia nitrogen removal rate were 81.82%,84.95%,92.15%,86.75 % respectively when the HRT were 2,3,4, 5h respectively. The best HRT was 4h.5. Through the experiment when the temperature was 25℃, the dynamic parameter of the biological active carbon fluid bed were obtained as follows: K_s=405.5 mg COD/L, q_max=7.855 mg COD/mg VSS·d,Y=0.818 mg VSS/mg COD and K_d = 0.106d^-1, compared with the traditional activated sludge, the biological active carbon fluid bed had the lower sludge field rate and less sludge increase quantity, which canreduce the later burden greatly.6. The relation between effluent substrate concentration S_e and sludge ageθ_c wasdeduced by dynamic parameter, which was S_e=405.5+42.98θ_c/6.32θ_c-1,and the relationbetween removal rate of load condensate U and sludge ageθ_c wasU=1+0.106θ_c/0.818θ_c.And the Monod equation was q=7.855×S/405.5+S.