高锰酸钾预氧化对有机物构型与超滤膜污染的影响

Effect of KMnO_4 pre-oxidation on organic configuration and ultrafiltration membrane fouling

以引黄水库水为水源,基于超滤组合工艺中试装置,考察KMnO4预氧化对有机物转化和超滤膜污染的影响。研究结果表明:原水以相对分子质量大于3×103的有机物为主,亲疏水性有机物比例相当。混凝沉淀主要去除疏水性与相对分子质量大于1×105的有机物,去除率分别为13.50%和47.06%。随投加量的升高,KMnO4对相对分子质量大于1×105的有机物去除率增加,同时产生了较多相对分子质量为3×103～1×105的有机物;水中疏水性有机物随之由降低变为升高。当KMnO4投加量适量时,可以减少膜污染,当投加量过高时,则会增加膜的不可逆污染。超滤膜去除的主要是疏水性有机物,相对分子质量大于1×105和1×104～1×105的有机物分别是造成膜可逆与不可逆污染的主要因素。超滤反洗废液中主要为相对分子质量大的疏水性有机物,化学清洗废液中的Mn含量随KMnO4投加量升高而增大。

A pilot test was carried out using ultrafiltration membrane as the core of combined process to treat reservoir water around Yellow river area to study different dosage of KMnO4 pre-oxidation＇s effect on organic configuration and ultrafiltration （UF） membrane fouling. The results show that the most part of organic matter is relative molecular mass of more than 3×10^3 at the same time the proportion of hydrophilic and hydrophobe organic is almost equal. Coagulationand sedimentation mainly remove the hydrophobic and relative molecular mass of more than 1×10^5 of organic matter and the removal rates are 13.50% and 47.06%, respectively. With the increase of dosage, KMnO4 pre-oxidation＇s removal rate of relative molecular mass of more than I ~ 10s organic increases while producing more 3×10^3-1×10^5 organic andmakes hydrophobic organic from lower to higher. KMnO4 can reduce membrane fouling when the dosage amount is feasible or can increase the membrane＇s irreversible pollution when the dosage amount is too high. UF membrane mainly removes hydrophobic organic. The relative molecular mass of more than 1×10^5 and 3×10^4-1×10^5 organic arerespectively major factor which causes reversible and irreversible membrane fouling. There are mainly high relative molecular mass and hydrophobic organic in UF backwash waste water and Mn concentration in the waster water of chemical cleaning increases with the increase of dosage of KMnO4.