A Study On The Removal Of Humic Acid By Enhanced Co-coagulation &Dissolved-air Flotation-Nanofiltration Integrated Process

Abstract the humic acid in the water is one of the most important NOM which affect the water quality stability and nowadays it has become the focus of notice in worldwide research. This paper mainly studied the removal of humic acid by enhanced co-coagulation-dissolved air fiotation-Nanofiltration integrated process and try the founded of the fractal dynamics model of dissolved air flotation.This experiment ascertain the most efficient dosage by measuring the turbidity CODmn, UV254 of DAF water under different dosage with the flocculant PAC, and studied the effect of Nanofiltration Membrane treatment by regarding the pretreatment water under the most efficient dosage as the inlet water of Nanofiltration installation .This study shows : the most efficient dosage is 0.64mmol/L to 10mg/L HA water sample by the treatment of the enhanced coagulation-dissolved air flotation unit, the most efficient dosage is 0.34mmol/L to 5mg/L HA water sample, the most efficient dosage is 0.20mmol/L to 1.5mg/L HA water sample, the most efficient dosage is 1.07mmol/L to 10mg/L HA water sample with 5mg/L Kaolin mixture water sample, the most efficient dosage is 0.34mmol/L to 10mg/L HA water with 5mg/L Kaolin mixture water sample.; It also shows that Kaolin will cause the negative effect to the total removal ratio of NOM by the comparison of treating different water samples which will decrease 1%~2%,especially to the carbon and NF membrane whose filtration capacity will reduce.; the UV254 of carbon filtration water and the membrane filtration water almost has the same UV254 which tells the carbon can absorb most of NOM absorbed by the NF membrane ; by the comparison of NF membrane made in OMNIPURE FILTER COMPANY and NF membrane made in APPLIED MEMBRANESINC COMPANY, it is found the two kinds of membranes almost has the same efficient function and they are excellent.Besides this paper will build the fractal dynamics model of by using the fractal theory and elementary ascertain the procedure of folc. Fractal dimension by collecting HA floc. From the micro-gyre floc, reactor, photo treatment, software computing, by which it analyses the fractal dimension change tendency with the dosage and got some conclusions.