曝气强度及间歇方式对SMBR膜阻力变化特征的影响

EFFECT OF AERATION INTENSITY AND INTERMITTENT TIME ON THE CHANGE OF MEMBRANE RESISTANCE IN THE SUBMERGED MEMBRANE BIOREACTOR

实验采用浸没式膜生物反应器(SMBR)对某石化废水进行处理,研究了曝气强度和间歇方式对SMBR膜阻力变化特征的影响。结果表明,在曝气强度分别为7.5、15、30 m3/(m3·h)时,跨膜压差(TMP)达到TMPmax(12 k Pa)的时间分别为12.17、15.67、29.33 h;TMP变化速率K分别由2.55、2.45、2.13 Pa/s上升到5.47、5.06、3.87 Pa/s;不可逆污染的阻力分别为41.0×109、52.4×109、100×109 m-1。采用3种不同运行方式(运行-间歇9 min-1 min、8 min-2 min、7min-3 min)时,达到TMPmax的时间分别为11.67、24.67、29.33 h,K分别由0.79、2.55、2.14 Pa/s上升到2.12、3.14、3.87Pa/s,总处理水量分别为17.33、33.66、33.87 L。因此,曝气强度增加在一定程度上会缓解膜污染速率,但会引起膜阻力构成特征的变化。延长间歇时间可以缓解膜污染速率并提升系统的总处理水量,但是间歇时间过长,对总处理水量的提升有限。

Submerged membrane biorcactor （SMBR） was employed for petrochemical industry wastewater treatment. Characteristics of the SMBR membrane resistance change was investigated under different aeration intensities and intermittent methods. The results showed that the operation time for reaching the maximum ofTMP （TMPmax） was 12.17, 15.67 and 29.33 h when the aeration intensity was 7.5, 15 and 30 m3/（m3·h）, respectively. The rate of change of transmembrane pressure K was increased from 2.55, 2.45 and 2.13 Pa/s to 5.47, 5.06 and 3.87 Pa/s, respectively. And irreversible membrane resistance was 41.0× 10^9, 52.4×10^9 and 100× 10^9 m^-1, respectively. The operation time for reaching the TMPmax was 11.67, 24.67 and 29.33 h while using different intermittent methods of 9 min （run）-1 min （break）, 8 min （run）-2 min （break） and 7 min （run）-3 min （break）, respectively. Meanwhile, K was increased from 0.79, 2.55 and 2.14 Pa/s to 2.12, 3.14 and 3.87 Pa/s, respectively. Total quantity of effluent in each operation cycle was 17.33, 33.66 and 33.87 L respectively. The results indicated that membrane fouling rate was decreased in some degree with aeration intensity increasing, which meanwhile led to the change of the composition characteristics of membrane resistance. Increasing intermittent time could result in a decrease in membrane fouling rate and an increase in the quantity of total effluent treated in each operation cycle. However, there was little increase in the quantity of total effluent when the intermittent time was too long.