Advanced Treatment Of Reservoir Water From Yellow River By Hybrid Processes Of Activated Carbon Filter And Ultrafiltration

In recent years, ultrafiltration technology as an efficient advanced water treatment process begins to receive attention. Turbidity removal by UF is very good, but the removal of dissolved organic matter by UF is poor, and UF is prone to fouling. To solve this problem, this thesis presents two hybrid processes, the hybrid process of up-flow activated carbon filter and UF (UACF-UF), and the hybrid process of GAC-sand dual media filter and UF (GACSF-UF), to strengthen the dissolved organic matters removal efficiency of settling tank effluent from Nanjiao Waterworks in Dongyin.The selection of activated carbon and sand, which are used in the two hybrid processes,is investigated. Then some important parameters of the two hybrid processes are optimized. The thickness of the carbon layer and the sand layer in GACSF is800mm and400mm respectively, and the filtration rate is8m/h; the upflow velocity of UACF is10m/h; the flux of UF is25L/(m2·h).The difference between UACF-UF and GACSF-UF in terms of the removal of organic matters and other pollutants is compared, by analyzing large amounts of data obtained from long-term trials. Turbidity removal efficiency by GACSF is higher than that by UACF, but turbidity removal efficiency of UACF-UF and GACSF-UF is about the same, which is considered to be attributed to the super turbidity removal efficiency capacity of UF. The performance on ammonia removal efficiency by UACF-UF and GACSF-UF is poor, which is considered to be attributed to low temperature. The ammonia removal efficiency by UF is not obvious. The removal efficiency and stability of CODMn and UV254by UACF is about10%higher than that by GACSF. The removal efficiency of CODMn and UV254by UF is not obvious. In terms of removing CODMn and UV254by microorganism, UACF performances better. The removal efficiency of bacteria by GACSF is about50%, thus UACF couldn’t remove bacteria but breeds bacteria.UF membrane fouling is also investigated. The initial TMP is determined by the turbidity of influent, and the fouling growth rate is determined by the organic matters in influent. When the membrane surface is clean, the fouling grows more quickly. When the cake layer forms, the fouling grows slowly. To fouled membrane, the recovery of permeable capability by physical clenning is limited. The performance on membrane cleaning by oxidiser is better than by acid. The oxidiser could destroy the construction of fluorescent substance. The main metal ions that lead to membrane fouling are Ca2+and Mg2+.The research process and result of the thesis can increase the experience about the removal of organic matters, and are technical references to the researchers in this field.