| Natural organic matter （NOM） are widely distributed in surface water, and differsgreatly in chemical structure and conformation as for organic species from differentsources. NOM not only reduce the efficiency of coagulation in treatment process andthe biological stability in distribution system, but also are the main precursors ofdisinfection by-products （DBPs） after chlorination disinfection. Magnetic ion exchange（MIEX） resin has the great potential to be used as effective approach to control theNOM. The thesis explored the removal efficiency of dissolved organic matter （DOC）and disinfection by-products by MIEX resin. The influence of resin dosage, contacttime, the content of DOC in raw water, the UV absorption value （SUVA） andanion-competitive effects on DOC removal efficiency were studied. The characteristicsof organic matter removed by MIEX resin were studied as well, in order to provideuseful information for the application of MIEX to control the NOM and DBPs undercertain conditions.MIEX resin was very efficient in removing the DOC and DBPs in the raw water.The removal efficiency were related not only to the resin dosage and contact time, butalso to the raw water quantity. The removal efficiency can be improved by increasingthe resin doseage or prolonging the contact time. When the resin dosage is1015ml/Land contact time is1020min，the DOC can be removed effectively for different rawwater. The DOC content of raw water had no relationship with the removal efficiency,but the removal efficiency were improved as the SUVA increasing. The highconcentration of NO3-and SO42-in raw water could reduce the removal efficiency ofDOC. The anion sequence removed by MIEX resin was SO42-, UV254, NO3-and DOC.The characteristics of organic matter were represented by the molecular weightdistribution, fractionation and three dimensional fluorescence spectroscopy （3DEEM） ofthe organic matter. MIEX resin was shown to be effective in removing bothhydrophobic and hydrophilic DOC, while conventional process could only removehydrophobic DOC. MIEX process was highly effective at removing small molecularweight organics and conventional process was shown to preferentially remove largemolecular weight organics. MIEX resin was shown to be effective in removing aromaticprotein and fulvic acid-like, which also had ability to remove the soluble microbialby-product-like. The conventional process was better at removing high molecular hydrophobicDOC. MIEX process followed by coagulation would improve the removal efficiency ofDOC and DBPs. |
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