Study On Wastewater Treatment Of Cassava Starch With An Up-Flow Multi-Stage Anaerobic Reactor

The paper studied on the feasibility and function of wastewater treatment ofcassava oxidized starch and crude starch with an up-flow multi-stage anaerobicreactor (UMAR). The up-flow multi-stage anaerobic reactor is a new styleanaerobic treatment, it also has methane to make use of, so it has good economicprofit and environmental profit.The author had done the UMAR experiment for more than 7 months,analyzed the second start-up of the full-scale UMAR in treating the starchproduction wastewater, the effluence factor of the reactor and the characteristicsof granular sludge were studied. During this period, the author controlled theoperation of the reactor by modulating the waterpower load and the volume load,seeing about index such as COD removal rate, SS, pH and VFA. Finally drew aconclusion as bellow: (1) Study on wastewater treatment of oxidized metamorphic starch with the up-flow multi-stage anaerobic reactor. Researched impactive influence of the pHand liquid flux. The study showed that the start-up of UMAR at the volumetricloading rate 5kgCOD/m^3. d, could be finished in 30 days. When the temperatureof the reactor changed between 30～35℃, it didn't has obvious influence on theCOD removal rate. The wastewater entered the reactor with the originalconcentration, The pH was not needed to be regulated. The system can show it'sbetter effect when the hydraulic retention time5h, pH7.28, and the COD removalrate was more than 83.2%, aerogenic rate was 0.52L/Ld.The volumetric loadingrate reached 30kgCOD/m^3. d.(2) Study on wastewater treatment of crude cassava starch with the up-flowmulti-stage anaerobic reactor. Researched the impactive influence of the liquidflux and COD concentration.The secondary start-up of UMAR could be finishedin 22 days.The temperature was controlled between 30～35℃, COD6500mg/L,pH7.15, volumetric loading rate 26kgCOD/m^3.d, hydraulic retention time 6h, thesystem showed it's better effect with the COD removal rate 92%, aerogenic rateof the system was 0.64L/Ld.(3) During the reactor's running steadily, The diameter of the granular sludgewas increased and the capability of the sedimentation was well. Throughmicroscope, several types of microorganisms were observed in the granularsludge, and Methaothrix was the main bacteria on the surface of the sludge,Mthanobacterium was the main bacteria inside the sludge. (4) After two groups of experimentation, The author contraposed the gas chrom-atography of the wastewater from the performance of UMAR, the result showedthat the amount of organic Substance changed in evidence.