AN ANAEROBIC DECOMPOSITION SYSTEM USING UASB BIOFILTER REACTOR FOR ENHANCING WASTE TREATMENT EFFICIENCY IN PAPER-RECYCLING FACTORIES

Objective: This paper proposes an anaerobic decomposition system using UASB biofilter reactor with a view to maximizing waste treatment efficiency in paper-recycling factories.Method: We used a rectangular Plexiglass upflow anaerobic sludge blanket (UASB) reactor with a capacity of 29 liters liquid(0.2m×0.25m×0.7m). The initial 29% of the reactor capacity was used for UASB maintenance and the upper 70% was filled with anaerobic biofilters in the form of plastic packs. For the purpose of initial inoculation, we mixed 19 liters of sewage sludge digester, 14 kg of cow dung and 7 liters of industrial waste treatment sludge. In order to adapt the bacteria to new waste and food, we added diluted waste to the tank for 10 days so that the materials were fully mixed. Meanwhile, we added a proportionate amount of urea and phosphate fertilizers to supply the Nitrogen and phosphor needed by bacteria.Results: The proposed system removed 78% of COD in organic loading rate of 7M3/ Kg COD added .d and upflow speed of 0.52 m/h. Since the efficiency did not significantly improve in higher organic loading rates, this rate was determined as optimal OLR. The results indicated that the system efficiency was directly associated with the reduced upflow speed and the increased time. Gas production value was 0.31M3/ Kg COD added. Conclusion: We concluded that the proposed anaerobic decomposition system efficiently treated the waste produced by Paper-recycling Factory in One City in North of Iran and met the national wastewater disposal standards

Keywords:

Anaerobic decomposition , paper-recycling factories , UASB biofilter reactor , Remove COD.