Study On The Resource Utilization Of Wastewater From Cellulose Production Process

A sewage source heat exchanger system is built in a cellulose production processing company in Tangshan to recovery heat from wastewater through heat exchange between wastewater (85℃-95℃) from cellulose production process and soft water. However, during the actual operation of heat exchange system, the scale forms rapidly on the surface of heat exchanger, which shortens the system’s normal working cycle and brings great inconvenience to the factory production work. So a fast, effective and reasonable cost wastewater treatment method is needed to prevent the possibility of scale forming on the surface of heat-transfer equipment, to prolong the normal work period of heat exchange system, and to improve the biodegradability of wastewater from cellulose production process.In this study,6 kinds of method, such as coagulation, adsorption, micro-electrolysis, Fenton oxidation, "micro-electrolysis+Fenton combination method" and "micro electrolysis+adsorption+Fenton combination method", are attempted to reduce the concentration of organic pollutants in wastewater from cellulose production process. The optimal operating parameters of each method are determined. According to the company’s requirements for wastewater treatment process, by comparison of each method’s treatment effect and reagent cost, the "micro-electrolysis+adsorption/Fenton coupling method" is the optimal method. The experiment result of treating wastewater in "Micro-electrolysis+adsorption/Fenton coupling method" indicates the reagent cost and treatment effect of the method meet the process requirements of the company. The experiment result of treating wastewater from cellulose production process in "Micro-electrolysis+adsorption/Fenton coupling method" indicates that the optimal operating parameters are as follows."Micro-electrolysis+adsorption/Fenton coupling method":pH value of micro-electrolysis is 3, reaction time is 20 minutes, and the dosage of micro-electrolysis filters is 270g/L; reaction time of adsorption/Fenton coupling unit is 10 minutes and the dosage of H2O2 is 25mmol/L. The adsorbent can be activated carbon (the dosage is 0.5g/L), fly ash (dosage is 8g/L) or pulverized coal (the dosage is14g/L). Respectively, the treatment reagent cost per ton wastewater is 3.81 yuan,3.21 yuan and 2.81 yuan, and the final CODCr of the wastewater is 435mg/L,412mg/L and 412mg/L. SO, in the Micro-electrolysis+adsorption/Fenton coupling method, the reagent cost and treatment effects meet the company’s requirements. The pulverized coal may be the optimal adsorbent, because it can continue to be used for combustion and to supply energy after being used.