Performance Evaluation and Kinetic Analysis of Photocatalytic Membrane Reactor in Wastewater Treatment.

Zeyad Zeitoun,Mohamed S Salem,Ahmed H El-Shazly,Mahmoud M Taha,Shaaban Nosier,Mohamed R Elmarghany

doi:10.3390/membranes10100276

Zeyad Zeitoun, Mohamed S Salem + Show 4 more

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https://doi.org/10.3390/membranes10100276

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Abstract

The objectives of the current study are to assess and compare the performance of a developed photocatalytic membrane reactor (PMR) in treating industrial waste (e.g., organic dye waste) against membrane distillation. The current PMR is composed of a feed tank, which is a continuous stirred photocatalytic reactor containing slurry Titanium dioxide (TiO2) particles that are activated by using ultraviolet lamp irradiation at a wavelength of 365 nm, and a poly-vinylidene flouride (PVDF) membrane cell. The experimental setup was designed in a flexible way to enable both separate and integrated investigations of the photocatalytic reactor and the membrane, separately and simultaneously. The experimental work was divided into two phases. Firstly, the PVDF membrane was fabricated and characterized to examine its morphology, surface charge, and hydrophobicity by using a scanning electron microscope, surface zeta potential, and contact angle tests, respectively. Secondly, the effects of using different concentrations of the TiO2 photocatalyst and feed (e.g., dye concentration) were examined. It is found that the PMR can achieve almost 100% dye removal and pure permeate is obtained at certain conditions. Additionally, a kinetic analysis was performed and revealed that the photocatalytic degradation of dye follows a pseudo-first-order reaction.

Highlights

The textile industry is one of the largest sources yielding tons of waste dyeing effluents that, even at low concentrations, reduce wastewater transparency, oxygen solubility, and are generally toxic [1,2].significant attention was directed to investigate different approaches for waste treatment before being discharged to the environment to meet the limitations imposed by legislation [3]
Deposition of the dye on the membrane surface occurs due to the attraction force between the negatively charged membrane and dye ions as mentioned above, retention of molecules increases gradually during the process and covers the membrane surface leading to repulsion between dye molecules adsorbed on the surface and dye molecules in the feed solution
For methylene blueblue (MB) concentration of 4 and 7 ppm, (Figures 10 and 11): interestingly, when we added the photocatalytic reactors with different TiO2 concentrations to the above experiments, 100% removal was achieved but with lower fluxes

Summary

Introduction

Significant attention was directed to investigate different approaches for waste treatment before being discharged to the environment to meet the limitations imposed by legislation [3]. Thermally-driven membrane processes have shown notable capabilities in removing different contaminants existing in wastewater [4]. There are four main configurations used for membrane distillation (MD) [5,6], as shown, the direct contact membrane distillation (DCMD) configuration [7] is the most widely used due to its simplicity and ease of application. The performance of different membrane fabrication materials was investigated, and it was found that polyvinylidene fluoride (PVDF), as a material for membrane fabrication, is a promising one due to its good film-forming ability, thermal stability, high mechanical strength, and excellent chemical and aging resistance [8]. Adopting MD for wastewater management was hindered due to some limitations; such as membrane fouling, wetting, high level of feed pretreatment requirements, and inability

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