TiO_(2)photocatalytic ceramic membranes for water and wastewater treatment:Technical readiness and pathway ahead

TiO_(2)is one of the best-known environmentally friendly photocatalysts that has demonstrated the great potential to degrade a wide variety of organic foulants in water and wastewater treatment when placed under UV radiation.Currently,TiO_(2)-based photocatalytic membranes are at the forefront of photodegra-dation research and technical readiness.The membrane setup provides a high contact surface area for ef-fective filtration and degradation,without the necessary hassle of photocatalyst recovery after water and wastewater treatment.Meanwhile,TiO_(2)photocatalytic ceramic membranes have become an emerging re-search area due to the inherent chemical and mechanical stability of ceramic membranes,which enables them to outperform polymeric membranes.With the recent shift from polymeric to ceramic membranes in industrial applications,TiO_(2)photocatalytic ceramic membranes will become a key player among the next-generation ceramic membranes,as they are capable of multiple functionalities.This review provides a timely and focused investigation into the fabrication and application of such TiO_(2)photocatalytic ceramic membranes for water and wastewater treatment.The benefits of using photocatalytic ceramic membranes in filtration,such as a higher foulant removal efficiency,higher water permeability,and much improved antifouling capabilities,are highlighted and explained.Finally,the current research,technical readiness,and remaining gaps are identified,and a set of critical insights are provided using the available data to guide the developmental pathway of practical TiO_(2)photocatalytic ceramic membranes for water and wastewater treatment.

High flux photocatalytic self-cleaning nanosheet C_(3)N_(4) membrane supported by cellulose nanofibers for dye wastewater purification

Hazardous dye substances discharged from the textile and dyestuff industries not only threaten local the surrounding ecosystems but are also hard to degraded.We report the preparation of process for a photocatalytic membrane device that can degrade dye pollution under visible light.This filtration membrane,with a well-organized multilayer structure,simultaneously achieves continuous and flow-through separation of degradation products.Cellulose nanofibers(CNFs)were used as a template for nanosheet C_(3)N_(4)(NS C_(3)N_(4))preparation;the performance for the photocatalytic degradation of dyes improved as the morphology changed from bulking to nanosheet.NS C3N4 was then attached to the surface of a prepared CNF membrane via vacuum filtration.This device exhibited high efficiency(the degradation rates of both Rhodamine B and Methylene blue both reached 96%),high flux(above 160 L·h^(-1)·m^(-2)·bar^(-1))and excellent stability(maintaining steady flux and high separation were maintained after 4 h).This easy-preparation,easy-scale-up,and low-cost process provides a new method of fabricating photocatalytic membrane devices for dye wastewater treatment.