scholarly journals Catalytic Membrane Ozonation

Encyclopedia ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 131-143
Author(s):  
Savvina Psaltou ◽  
Manassis Mitrakas ◽  
Anastasios Zouboulis

Catalytic membrane ozonation is a hybrid process that combines membrane filtration and catalytic ozonation. The membrane deposited with an appropriate solid material acts as catalyst. As a consequence, the catalytic membrane contactor can act simultaneously as contactor (i.e., improving the transfer/dissolution of gaseous ozone into the liquid phase), as well as reactor (i.e., oxidizing the organic compounds). It can be used in water and wastewater treatment limiting the disadvantages of membrane filtration (i.e., lower removal rates of emerging contaminants or fouling occurrence) and ozonation (i.e., selective oxidation, low mineralization rates, or bromate (BrO3−) formation). The catalytic membrane ozonation process can enhance the removal of micropollutants and bacteria, inhibit or decrease the BrO3− formation and additionally, restrict the membrane fouling (i.e., the major/common problem of membranes’ use). Nevertheless, the higher operational cost is the main drawback of these processes.

Author(s):  
Yang Hu ◽  
Yue Peng ◽  
Wen Liu ◽  
Dongye Zhao ◽  
Jie Fu

Conventional water/wastewater treatment methods are incapable of removing the majority of Emerging Contaminants (ECs) and a large amount of them and their metabolites are ultimately released to the aquatic environment or drinking water distribution networks. Recently, nanofiltration, a high pressure membrane filtration process, has shown to be superior to other conventional filtration methods, in terms of effluent quality, easy operation and maintenance procedures, low cost, and small required operational space. This chapter provides a comprehensive overview of the most relevant works available in literature reporting the use of nanofiltration for the removal of emerging contaminants from water and wastewater. The fundamental knowledge of nanofiltration such as separation mechanisms, characterization of nanofiltration membranes, and predictive modeling has also been introduced. The literature review has shown that nanofiltration is a promising tool to treat ECs in environmental cleaning and water purification processes.


2003 ◽  
Vol 47 (1) ◽  
pp. 89-95 ◽  
Author(s):  
J. Yu ◽  
D.D. Sun ◽  
J.H. Tay

Ferric chloride and aluminium sulphate as coagulants and positive charged flocculants PDDMAC ((PDDMAC = poly (diallyldimethylammonium chloride) were used for pre-treatment of water and wastewater for removing humic substance prior to RO membrane filtration. It was found that a combination of flocculant and coagulant enhanced the coagulation-flocculation process and humic acid removal. The optimum conditions of coagulation-flocculation were established in reference to the ratio of humic acid and coagulant. Zeta potential and the ratio of E4/E6 were investigated to explore the possible micro-mechanisms of coagulation-flocculation. The ratios of E4/E6 show the molecular size variations using different coagulants and flocculants, which are expected to benefit membrane-fouling control.


2018 ◽  
Vol 34 (5) ◽  
pp. 657-693 ◽  
Author(s):  
Sareh Kheirieh ◽  
Morteza Asghari ◽  
Morteza Afsari

Abstract Polysulfone (PSf) is a favorite polymer for the production of membrane due to its excellent physicochemical properties, including thermal stability; good chemical resistance to different materials such as different bases, acids, and chlorine; sufficient mechanical strength; and good processability. The present study offers an overview of the recent development in the application and modification of PSf membranes, focusing on some applications such as water and wastewater treatment, membrane distillation, pollutant removal, gas separation, separator for lithium ion battery, and support of composite membranes. In general, there are two major difficulties in the use of membranes made of PSf: membrane fouling and membrane wetting. Therefore, PSf membrane with good anticompaction and antifouling properties is reviewed. Finally, important issues related to the modification of PSf membranes for real applications are discussed. This article provides an intelligent direction for the progress of PSf membranes in the future.


2021 ◽  
Author(s):  
Westphalen Dornelas Camara Heloisa

Membrane separation processes have been more widely applied to industrial activities, especially in water and wastewater treatment. However, there are still challenges associated to the use of membranes. Concentration polarization and fouling can cause significant permeate flux decay during the filtration process, hindering its efficiency and increasing cost. Among many strategies, the combination of membrane filtration with ultrasound (US) application has shown promising results in reducing membrane fouling. The main goal of this research was to identify the effect of US frequency, US power intensity and feed solution concentration on permeate flux during ultrafiltration of simulated latex paint effluent. Maximum increase in permeate flux of 19.7% was obtained by applying 20 kHz and 0.29 W.cm-2 to feed solution with 0.075 wt.% of solid concentration. The effect of feed flow rate was analyzed showing that an increase in feed flowrate is not beneficial to the fouling minimization process. Overall, the application of US improves permeate flux by reducing fouling of ultrafiltration polymeric membrane.


2004 ◽  
Vol 50 (12) ◽  
pp. 119-124 ◽  
Author(s):  
K.W. Chau

The fractal structure and particle size of flocs are generally recognized as the two most crucial physical properties having impact on the efficiency of operation of several unit processes in water and wastewater treatment. In this study, an experimental investigation is undertaken on the effect of aggregate structure in water and wastewater treatment in Hong Kong. The fractal dimension of the resulting aggregate is employed as a measure of the aggregate structure. Small angle light scattering technique is used here. Different amounts of polymers are mixed to bacterial suspensions and the resulting structures are examined. The addition of polymer may foster aggregate formation by neutralization of the bacterial surface charge and enhance inter-particle bridging. The aggregation behavior may affect the efficiency of certain water and wastewater treatment processes such as dewatering and coagulation. The impacts of aggregate structure on two representative processes, namely, ultra-filtration membrane fouling and pressure filter dewatering efficiency, are studied. It is found that the looser flocs yield a more porous cake and less tendency to foul whilst more porous filter cakes yield more ready biosolids dewatering.


Author(s):  
Manoj Kumar Karnena ◽  
Madhavi Konni ◽  
Bhavya Kavitha Dwarapureddi ◽  
Vara Saritha

Abstract: One of the several significant concerns related to water treatment plants is the transformation of natural organic matter (NOM) concerning quality and quantity due to the changing climatic conditions. The NOM consists of heterogeneous functionalized groups. Phenolic and carboxyl groups are the dominant groups that are pH-dependent and show a stronger affinity towards the metals. Properties of natural organic matter and trace elements govern the binding kinetics, influencing cations' binding to functionalized groups at lower pH. The water treatment process mechanisms like adsorption, coagulation, membrane filtration, and ion exchange efficiencies are sturdily influenced by the presence of NOM with cations and by the natural organic matter alone. The complexation among the natural organic matter and coagulants enhances the removal of NOM from the coagulation processes. The current review illustrates detailed interactions between natural organic matter and the potential impacts of cations on NOM in the water and wastewater treatment facilities.


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