Study On Treatment Of Mechanical Straw Pulp Recycling Water By Flocculation And Self-Filtration Methods

Due to the development of industry and agriculture, the raise of population, human's limited water resource has been polluted seriously day by day. Recent years a great deal of attentions have been paid to new clean pulping technology to reduce pollution emissions, which provided a new way to development for the pulp industry.Mechanical straw pulp which has simple production process,low production cost,high yield and good printing performance.These advantages made it to be the pulping process which have been applied to promote worldwide.In this study,mechanical pulp wastewater treatment with flocculation based on properties of mechanical straw pulp was studied.The influence of feeding method, flocculant dosage and flocculating conditions was investigated, flocculation mechanism was also discussed. The best contitions were found was that first adding PACl dosage was 200mg/L, then adding APAM dosage was 20mg/L,temperature was 35℃, reaction time was 20min After flocculant the removal rate of SS and CODcr was over 94.3% and 54.6%.In order to enhance the effectiveness and application of operational.A type of device for the flocculant and self-filtration process was designed,the influence of conditions for device operation, effect of zeolite and process optimization was investigated.The best contitions for device operation were found was thatfirst adding PACl dosage was 150mg/L, then adding APAM dosage was 15mg/L, last adding zeolite dosage was 200mg/L and detention time in the device was 30min.Under the action of flocculant and zeolite self-filtration layer was formed,After flocculant and Self-filtration, the removal rate of SS and CODcr was over 90% and 60%. The process had satisfactory results in mechanical straw clean pulp wastewater treatment, and final effluent can be used as recycling water. Then device can enter into the continuous running mode.In addition, device deodorant was also tried, due to this part had less associate with the investigation, the studies were not go to deeper.