Photocatalytic membrane reactors for degradation of organic pollutants in water
Photocatalytic membrane reactors for degradation of organic pollutants in water
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DOI：
10.1016/s0920-5861(01)00314-5
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发表时间：
2001-05-15
期刊：
影响因子：
5.3
通讯作者：
Schiavello, M
中科院分区：
文献类型：
--
作者：
Molinari, R;Grande, C;Schiavello, M
不同的流程（间歇式和连续式）的光催化膜反应器，用于降解水中存在的有机污染物，连同一些实验结果，报告。4-以硝基苯酚（4 NP）为探针污染剂，悬浮态二氧化钛为催化剂。在分批系统中的光降解试验进行无膜改变的过程中的特征变量（光强，TiO 2浓度，4 NP浓度，O-2浓度，pH值），以找到它们的最佳值。分批系统由水套恒温和搅拌烧杯组成，从上方用UV-Vis灯（液体表面上的光强度为3.4mW/cm（2））照射。获得了描述反应速率作为报告变量的函数的经验预测方程。在膜反应器（总体积为400 - 700 ml）中进行光降解试验，将批料与含有各种类型的平片膜的再循环池连接，所述平片膜能够保留悬浮的催化剂并对污染物具有部分选择性。膜为：NTR 7410和NTR 7450（Nitto Denko）; N30 F和NF-PES-010（Hoechst）; MPCB 0000 R98（SEPAREM）。测得的渗透通量在4巴下为5-30 l/h m（2），所有膜均显示出截留率和吸附污染物的能力，在4巴下的过渡阶段为80 - 400 min。这种行为可能对该过程有益，因为污染物浓度的振荡不会在渗透物中传递。三个因素：排斥，光催化降解和吸附能够保持渗透液中的4 NP浓度在非常低的值。对于连续系统，在渗透物中的最低4 NP浓度为6-7%（w/w）的初始4 NP浓度（40毫克/升）经过300分钟的过渡期。该过程的进一步改进正在调查中。(C)2001 Elsevier Science B. V.保留所有权利。
Different flowsheets (batch and continuous) of photocatalytic membrane reactors, to be used for degradation of organic pollutants present in water, together to some experimental results, are reported. 4-Nitrophenol (4NP) was used as a probe polluting agent and titanium dioxide in suspension was the catalyst. The photodegradation tests in the batch system were carried out without membrane changing the characteristic variables of the process (light intensity, TiO2 concentration, 4NP concentration, O-2 concentration, pH) to find their optimum values. The batch system consisted of a water jacket thermostatted and stirred beaker irradiated from above with a UV-Vis lamp (light intensity on the surface of the liquid 3.4 mW/cm(2)), An empirical predictive equation was obtained describing the reaction rate as a function of the reported variables. Photodegradation tests in the membrane reactors (total volume from 400 to 700 mi) were carried out coupling the batch to a re-circulation cell containing various types of flat sheet membranes which were able to retain the suspended catalyst and partially selective to the pollutant. The membranes were: NTR7410 and NTR7450 (Nitto Denko); N30F and NF-PES-010 (Hoechst); MPCB0000R98 (SEPAREM). The measured permeate flux was in the range 5-30 l/h m(2) at 4 bar and all membranes showed both a rejection and a capacity to adsorb the pollutant with a transitory phase varying from 80 to 400 min at 4 bar. This behaviour could be a benefit for the process because oscillations in the pollutant concentration are not transmitted in the permeate. Three factors: rejection, photocatalytic degradation and adsorption were able to maintain the 4NP concentration in the permeate at very low values. For the continuous system, the lowest 4NP concentration in the permeate was 6-7% (w/w) of the initial 4NP concentration (40 mg/l) after a transient period of 300 min. Further improvements of this process are under investigation. (C) 2001 Elsevier Science B.V. All rights reserved.