Study On Treatment Of Waste Paper Recycled Pulping Wastewater By Biological Enzyme-Assisted Microbial Fuel Cell

Starch substances are widely used in papermaking process,resulting in a large number of starch entering into papermaking water system in the recycling process of waste paper,which not only affects the chemical balance of the wet end of papermaking,but also increases the amount of papermaking additives,affects the operation of paper machine and the quality of paper,and causes great pressure on water treatment,directly affects the development of papermaking circular economy.Especially in the production of packaging paper enterprises with domestic waste carton raw materials,this problem is particularly prominent.In this thesis,we use biological enzyme to extract starch organics from the raw materials of waste cartons.After saccharification,we use microbial fuel cell(MFC)to transform it into biomass energy for generating electric energy.This not only can purify fiber raw materials,reduce the burden of papermaking wastewater treatment,improve the sustainable development level of papermaking industry,but also can realize the conversion of biomass energy and generate electricity,which has far-reaching strategic significance.By optimizing the process of extracting starch organic matter from waste pulp treated by a-amylase,the optimal conditions are as follows:the amount of ?-amylase used to treat waste pulp is 0.5%(500 u/g starch),the concentration of waste pulp is 10%,the pH value is 6.5,the reaction temperature is 70,the treatment time is 60 min,under which the organic matter extraction rate is the highest.After ?-amylase treatment,the absolute value of zeta potential and cation demand of white water of waste pulp decreased by 17.2%and 20%.The strength of handsheet of enzymatic treated pulp is slightly lower than that of control group,but the reaction of pulp in the application of cationic starch as reinforcer is more sensitive at lower dosage.The related mechanism needs further study.The saccharification of starch extract by glucoamylase was studied,and the optimum conditions for the reaction of starch extract to produce reducing sugar were explored.The results showed that the optimum conditions for the preparation of saccharifying liquor were 1.0%of the enzyme dosage,60?,90 min of treatment time and 4.0 of the reaction pH value.Under the optimal conditions of liquefaction of alpha-amylase and saccharification of glucoamylase,the reducing sugar content accounted for 68.82%of starch content and 9.95%of the sample quality,i.e.the organic matter content was about 99 kg per ton of raw paper.The co-use of alpha-amylase and glucoamylase to treat regenerated pulping wastewater from corrugated paper has obvious feasibility in paper industry.The reaction of microbial fuel cell to saccharification solution was studied to convert biomass energy.The results show that the microbial fuel cell can start up smoothly with the starch saccharification liquid/pulping waste liquid treated by ?-amylase and saccharifying enzyme as the substrate.The highest voltage of MFC cell is 136 mV,and the COD removal rate in 24 hours is 62.58%.It shows that MFC battery has a good effect on the treatment of starch saccharification liquid/pulping wastewater pollution load.