Project Of Advanced Treatment And Reuse Of Pulp And Paper Wastewater

Pulp and paper industry is one of the most serious polluted wastewatervocation.With the improvement of environmental quality requirement, high pollutionand high use of water has restricted the development of pulp and paper industry.Technology research of high efficiency and low energy expenditure is in demanded forthe healthy development of pulp and paper industry."Magnetic-imitation of enzyme treatment" was used to treat pulp and paperwastewater in this topic. Secondary effluent of pulp and paper wastewater analyses，process comparison of pulp and paper wastewater, pilot study of pulp and paperwastewater, project design of pulp and paper wastewater,and treatment efficiency ofpulp and paper wastewater demonstration project were studied. The results are asfollows.(1) Secondary effluent of pulp and paper wastewater existed mainly in the form ofdissolved state, and the molecular weight of most organic contaminants were under1KDa. Lignin was the main treatment object because half of the CODCrof wastewaterwas produced by it.(2) Compared with the traditional coagulation process and fenton oxidationprocess,the pulp and paper wastewater treatment process was better not only in treatingCODCrand chromaticity color,but also in saving the treatment costs.It achieved thebenefits of win-win situation of efficiency and environmental.(3) The pilot study results of using " Magnetic-imitation of enzyme treatment"combined process to treat pulp and paper wastewater were as follows:The effluentCODcr was39mg/L~53mg/L, color6to10fold, conductivity3421μs/cm~3508μs/cm,and total hardness132mg/L~149mg/L when influent CODcr was285mg/L~317mg/L,color320to350fold, conductivity3270μs/cm~3356μs/cm, and total hardness317mg/L~349mg/L. The effluent could meet the national pulp and paper wastewaterdischarge standards（GB3544-2008）.(4) Demonstration project operating conditions shows that the effluent waterquality of this process system was stable In the case of the unstable influent water. Theeffluent CODcr was38mg/L～60mg/L, color10to20fold, SS0～30mg/L,conductivity3157μs/cm～3473μs/cm, and total hardness146mg/L～184mg/L when influent CODcr was 235～374mg/L, color355to385fold, SS67mg/L～84mg/L,conductivity3005μs/cm～3287μs,and total hardness320mg/L～472mg/L. The wastewater treatment process costs1.31yuan/m3including chemicals and electricity consumption.The treatment efficiency of " Magnetic-imitation of enzyme treatment " processwas studied on the basis of the pulp and paper wastewater quality characteristics. Amaturity and reliable pulp and paper wastewater treatment process was formed.Thisprocess provided a technical support for the discharge standards of national pulp andpaper wastewater （GB3544-2008）,and laid a solid foundation for the healthydevelopment of pulp and paper industry.