Adorption Characteristic Of Natural Orgnic Matter As Monitored By The Quartz Crystal Microbalance And Application In Coagulation

Nowadays one of the most important issue in water treatment is to removal the Disinfentions by Products (DBPs).Enhanced coagulation is the best available technology to control Disinfentions by Products (DBPs) for its high efficiency and low cost to removal DBPs precursor (TOC).The paper first use the technology of Quartz Crystal Microbalance (QCM) to study the Adorption characteristic of Natural orgnic matter on alumina which is coated on wafer.The experiment that using a quartz crystal microbalance with dissipation monitoring (QCM-D) to investigate humic acid (HA) adsorption onto alumina (Al2O3) could prove the degree of adsorption and layer structures of HA by the real-time monitoring of resonance frequency and energy dissipation changes (Δf andΔD).The effect of HA concentration, HA molecular characteristics (molecular weight and polarity), and pH on HA adsorption onto Al2O3 were investigated. HA is more adsorbable onto alumina at weakly acidic pH values because the adsorbed layer is more non-rigid. This reveals that efficient HA removal by coagulation at weakly acidic pH values is not just due to the hydrolysis of Al ions as previously presumed. HA of hydropHobic character and high molecular weight is more adsorbable onto alumina than HA of hydropHilic character and low molecular weight. The mass adsorption for the hydropHobic fraction is about four times high than the hydropHilic fraction (120 ng cm-2 and 30 ng cm-2). The adsorbed layer of hydropHobic HA is more non-rigid than hydropHobic HA.These result could be useful in subsequent research to establish a quantified calculation model for the coagulation process.The study of real water using QCM proved the same conclusions which humic acid (HA) adsorption onto alumina has educed before.And also proved that the NOM adsorbed mmuch when the value of SUVA is hight.The FeCl3 AlCl3 Al13 and PAC were used to do the Jar Test in the lab.The waters one was made in the lab,the others were took from two river that is songhuajiang and qiantangjian.when the HA contents large percent of hydropHobic orgnic matter,large molecule,the removal of HA is much.This is consistent with the conclusion obtained of QCM experiment. The Jar Test also provides scheme to the two real waters and analysised the factors which hold back the removal of HA. Hopes this can privde some evidences to latter researches.