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The study on the start-up of the pilot-scale immobilized and suspended biomass combination processing to treat the comprehensive effluent from a wheat straw pulp and paper plant was performed. The carrier packing selected in this experiment is a new type of microbial carrier (modified polyurethane foam plastic packing) which dosing rate was 20% of the reactor volume. The low quantity of inoculation sludge way is used to start the system. The test results show that the removal efficiency of COD and SS by the immobilized and suspended biomass combination technology system after a weak or so can be stable, as the effluent SS was below 50mg/L, the removal rate of 95% or more and the effluent COD was below 260mg/L, the removal rate of 85% or more. From start to 10th day, the attached sludge concentration on biomass conversion was more than 20g/L, while the microscope observation to biological adherent microbes suspended sludge and carrier phase indicated abundant microbial species. The fact indicates that the start-up can be finished in 10 days.

The treatment on the secondary biochemical effluent of pulp and paper wastewater by Fenton oxidation was studied and the influence of H2O2dosage, Fe2+dosage, pH and reaction time on the treatment effect was investigated by the orthogonal test and single-factor test. The treatment effect was eminent when the H2O2dosage was 3.75mmol/L, Fe2+dosage was 3.20mmol/L, pH was 4.00 and the reaction time was 80.00min. The removal rate of UV254and chromaticity significantly increased as H2O2dosage was 1.88 ~ 3.75mmol /L, but the COD removal rate declined as H2O2dosage was more than 2.81mmol/L; each removal rate increased and then decreased slightly with the increase of Fe2+dosage, each removal rate dropped obviously as pH was more than 5.00; within 80.00min, the removal rate increased significantly, it changed little with the continuous increase of reaction time. Under the optimal conditions, the COD removal with Fenton oxidation was more effective and its removal rate could achieve 88.33%, it was advantageous compared with ozone oxidation; but the elimination effect of UV254and chromaticity to pulp and paper wastewater with ozone oxidation was better, the two removal rate achieved 83.70% and 92.00% in a short time, respectively. Although it could reach such a removal effect by Fenton oxidation, it did not have the superiority in reaction time.