The Study On The Treatment Of Reservoir Water Derived From Yellow River By The Technology Of Flofilter

The study is part of the " Research and Demonstration of the Technology Combination of Purification Process as the core of Flotation", which is the third sub-topic of the "The Research and Demonstration of integration technology of conventional process in the treatiment of Yellow River reservoir with high algae". That is the third subject of " Research and Integrated demonstration of Novel Technology for Drinking Water Safety in the Downstream of Yellow River ".The water quality characteristics of reservoir water derived from Yellow River are algae blooming in summer and low temperature and low turbidity in winter. The study made reservoir water derived from Yellow River in Jinan city as object. Based on those typical characteristics, the flofilter, whose treatment scale was 5m3/h, had been designed.The contents of this study include four aspects:(1) the design of flofilter pilot device; (2) the optimum study of function conditions on the flofilter technology treating low turbidity water; (3) the experimental research on low temperature and low turbidity water treatment by flofilter technology; (4) the analysis of function conditions of quartz sand and activated carbon filter layer.Through the optimum study on flocculation, it could be seen that PAFC was suitable for reservoir water derived from Yellow River, and the optimum dosage of PAFC was 4.0mg/L(Al3+). Meanwhile, the technical performances of PFAC were analyzed and the regression curve between the Indicators and flocculation dosage with polynomial equations were launched. It was concluded that the correlation between turbidity and the dosage of PFAC was the best, following by CODMn, UV254 and chloropHyll.The running effects caused by different loading rates, recycle rates of water disolved with gas and craping residue cycle were launched in the the optimum experiment on parameters of flotation unit. It was conclused that the loading rate should not exceed 8m3/(m2·h), the optimum recycle rate was 18%, and the scraping residue cycle should not exceed 3h.Through the enhanced coagulation test in the low temperature and low turbidity period, a high performent polysilic aluminum ferric chlorides was used and the optimum dosage of PAFCSi was determined to be 0.5mg/L(Al3+). The orthogonal experimental results showed that the optimal levels of various factors were as follows: recycle rate 18%, water flow 5m3/h, mixed reaction speed 130r/min and flocculation speed 40r/min. From the study on the removal of all indicators by preoxidation flofilter process, it could be seen that KMnO4 preoxidation obtained better effect than ClO2 preoxidation.Micro-flocculation direct filtration experiment which investigated filtration rate on the impact of the removal of pollutants was conducted through the study of the function conditions of quartz sand and activated carbon filter layer. The results showed that the removal of indications especially for TOC, UV254 and other organic indications declined with the increace of filtration rate. That was why it recommend the filtration rate of flofilter pilot device should not exceed 6m/h. Meanwhile, the operating performances of the filter layer in a filter cycle were examined, and the pollutants removal efficiency and dominant position were analyzed. The variations of the filter head loss over time were also appraised. It was ultimately concluseded that the backwashing cycle of filter layer was determined by the surface filter layer, and preferably should not exceed 3d.According to the analysis of biological performances of activated carbon, the biomass of activated carbon filter layer was test with lipid pHospHorus method after flofilter having operated stably for three months. The result was 5.23×106 Per gram activated carbon, which suggested that the activated carbon filter layer had gathered a certain number of microbes. They could play a certain role in biodegradation. Simultaneously, the synergy between flotation process and bioperformance of activated carbon was analyed. The results showed that in addition to UV254, the floatation-filter performed better on the removal of other indicators. Compared with the direct filtration proess, the removal rate of CODmn, UV254, NH4-N, TOC respectively increased by 3.18%,9.60%,0.69%,2.41%in floatation-filter proess. It was indicated that dissolved air water enhanced the bioperformance of activated carbon layer without obvious effect.