Shananxi One Paper Mill Straw Pulping Wastewater Advanced Treatment Experimental Study And Engineering Design

Pulp and paper industry wastewater has high concentration of organiccompounds and composition more complex. After two stage biochemicaltreatmeat the effluent biochemical performance is poor. The common treatmentmethod of wastewater is very difficult to continue to degrade. The national andShaanxi province in the pulp and paper industry effluent put forward more strictstandards, resulting in the territory of Shaanxi many enterprises wastewaterdischarge is not up to the national" pulp and paper industrial water pollutantdischarge standard"（GB3544-2008） and the the Yellow River River Basin inWeihe to the" Shaanxi provincial standard"（DB61/224-2011）requirements,which prompted the Shaanxi province pulping papermakingenterprises have additional wastewater advanced treatment.Wastewater treatment method has a lot of, coagulation treatment methodand adsorption method by a lot of enterprises reference, although the cost isrelatively low, but the effect of wastewater treatment is poor; micro electrolysisprocessing method and membrane separation hair treatment effect is good, butthe high cost of processing, it is not suitable for enterprise application; for theenzyme treatment method is still remain in the experimental stage, the promotionof technology market remains to be verified; ecological treatment method isgenerally added to other advanced treatment method of terminal system, aseparate section as wastewater treatment effect is not very reliable; advancedoxidation processing method at present relatively mature technology, the FentonTechnology is widely used in the market, and the evident effect of wastewatertreatment at present, it is the mainstream technology in wastewater treatment.In May,2011, Shaanxi University of Science and Technology PapermakingResearch Institute of environmental protection and one Shaanxi paper mill signed a wastewater advanced treatment project. And the project uses the Fentonoxidation treatment for wastewater. The subject of the engineering project,obtained through the test suitable for wastewater treatment process based onFenton data, and then after the completion of Engineering design.Part of the experiment to the enterprise two sink the pond effluent as theresearch object, the first use of a certain amount of PAM for wastewater bycoagulation pretreatment, make Fenton reaction water quality CODcr in200mg/L or so, and then from the different reaction time, the amount of H₂O₂,FeSO₄dosage and reaction pH value of Fenton reaction technology forwastewater treatment effect, suitable for the project of Fenton wastewatertreatment process parameters.The experimental results show that: Response on water without the need forconventional acidizing treatment, FeSO₄dosage is1.0g/L, H₂O₂（30%）0.5ml/L,reaction time is30⁴0min.Then pH value of water is adjiust6⁹. Finally, thewater of locaccted by2per thousand of the PAM flocculation the pondprecipitation effect can make the final effluent CODcr goes down to50mg/L, theremoval rate reaches above75%, the effluent meets national and localenvironmental effluent requirement, and processing cost is low.Design according to experimental parameters, the operation of mill and theShaanxi University of Science and Technology Paper Environmental ResearchInstitute to help finish. water treatment scale is25000m³/D in the design. Waterquality for CODcr is300mg/L, BOD₅20mg/L, SS80mg/L, pH value6-9. Forthe effluent after treatment, CODcr is less than50mg/L, BOD₅less than10mg/L,SS less than30mg/L, pH for6⁹.Engineering design process: water flows from the existing secondarysedimentation tank into the sump, and then enters into the1#flocculationreaction pool for coagulation reaction, and then enters the third sedimentation,tank for sedimentation, and then enter the system core Fenton reaction pool.Thewater orderly passes through the pH/degassing regulation pool,2#flocculationreaction pool and fourth sedimentation tank to achieve standard discharge.Design also includes a selection of equipment, and other supporting engineeringdesign.After completion of the project, wastewater treatment system by debugging and operation display: each part of system stable operation, simple operation andreliable safety.Water station continuous monitoring data show: the final effluentquality can be stabilized with CODcr40mg/L, BOD₅10mg/L, SS25mg/L, pHvalue6⁹, and each index have reached the agreement, meet national and localenvironmental standards emissions requirements,The system was able todischarge according to standards and the operation cost was low.