Study On A Bio-diatomite Technology For Municipal Wastewater Treatment

The disadvantages of applying the chemical enhanced diatomite to treat the wastewater include the low efficiency with organics, no impact on ammonia-nitrogen and unstable anaerobic effects at the suspended layers. As such, considering that diatomite has good effects on phosphorous removal, and biological treatment is good at nitrogen removal, The bio-diatomite technology is designed based on the anaerobic-aerobic biological treatment process and transforms the chemical enhanced treatment technology to a integrated technology which uses the diatomaceous earth as the microorganism carrier to remove phosphorus via chemical mechanism and remove carbon and nitrogen via biological mechanism. The process applying the bio-diatomite technology and substituted the traditional secondary sedimentation tank by suspended clarification tank to treat municipal wastewater is named A/O/C-BD process .The study developed the smalland middle pilot studies on municipal wastewater treatment. Research includes the selection of design parameters, cultivation and acclimation of the microorganism, operation condition parameters and affection factors and the pollution removal mechanism.The filoc-forming bacteria was in a complete mixing status and the microorganism concentration was kept replying on the sludge recycle in A/O/C-BD process. The microorganism attached to the surface of diatomite formed the bio-membrane with the carrier as diatomite. Comparing with the normal nitrogen and phosphorus removal biological process, the diatomite is advantage in longer sludge age (23—35d)and lower generation rate of sludge(0.18⁰.39kgVSS/kgBOD₅), and the higher nitrification rate and denitrification rate(9.95mg (NH₄⁺-N) /gVSS.h and 6.78mg (NO₃^--N) /gVSS.h respectively). This process combined the characteristic of the activated sludge process and bio-membrane process therefore it increases the wastewater treatment efficiency. This also provides a valuable technology of adopting the superfine powder as the microorganism carrier.Based on the small-scale pilot studies, it is indicated that the removal efficiency...