Micropollutant Removal from Water by Membrane and Advanced Oxidation Processes—A Review

Abstract

Micropollutants are defined as contaminants found in trace concentrations in water bodies that are persistent and bioactive, meaning they are not completely biodegradable and cannot be removed by conventional water treatment methods. Because of these aspects, their detection and removal pose a challenge to the scientific community. Among them are endocrine disruptors, drugs, agricultural chemicals, personal grooming products, industrial additives and others. These micropollutants are the cause for global concern, because their presence in water supply systems is suspected of causing health problems in humans and animals. To develop efficient techniques to remove them, it is fundamental to understand their physico-chemical properties and the available treatment types and conditions. Membrane separation processes (MSPs) and advanced oxidation processes (AOPs) are the focus of this literature review, as potential treatment methods to remove micropollutants. The former process stands out for high rejection rates (above 90%) of various micropollutants, but it generates a concentrated secondary waste stream. In turn, the latter process can remove micropollutants without generating secondary wastes, and can also be applied and combined with other treatment methods.

Exclusion of Estrogenic and Androgenic Steroid Hormones from Municipal Membrane Bioreactor Wastewater Using UF/NF/RO Membranes for Water Reuse Application

“…The physico-chemical properties of E2 and T are considered as responsible for influencing their rejection by UF/NF/RO membranes [5,46]. This can be observed in Figure 3A, B, where the MBR/RO treatment removed all the test samples of E2 below LOD < 0.25 ng/L, regardless of the specific Variations in the pilot plant operating conditions in Table 1 (flux and pH) did not have any visible effect on the removal of E 2 and T for the MBR/UF, MBR/NF, and MBR/RO processes.…”

“…These natural hormones are responsible for maintenance, reproduction, development, and behaviour of organisms [4]. Among the sources of these substances are natural steroid hormones, 2 of 17 industrial chemicals, pharmaceuticals, and many others [5]. Many researchers have investigated the effect of these substances in water bodies, observing harmful effects on humans and animals, such as endocrine system anomalies, cancer, reduction of sperm quantity, and endometriosis [6].…”

A comprehensive analysis of membrane fouling in microfiltration of complex linear macromolecules based on theoretical modeling and FESEM images

“…In this regard, micropollutants (MPs) including natural organic matter (mainly proteins) 1 , chemicals used as pharmaceuticals and personal care products and endocrine‐disrupting compounds, as well as inorganic substances such as heavy metals and toxic anions have been detected in water bodies and identified as potential threats to aquatic ecosystems and human health. Even more challenging is that organic trace compounds can act synergistically with other components, aggravating the negative effects 2 . Hence, restricting water contamination/pollution is a high‐agenda item for most countries and a matter of global concern.…”

A Novel UV-C/XOH(X=Na or K) Based Highly Alkaline Advanced Oxidation Process (HA-AOP) for Degradation of Emerging Micropollutants

“…In the last few decades, several AOPs ( Table S1) have been studied and upgraded for enhanced, effective and efficient removal or degradation of several emerging micropollutants such as dyes and pharmaceuticals. [1][2][3][4][5] Conventionally, these AOPs' applications at different places used to offer an inevitable feasibility to reduce the concentration of organic pollutants (from ppm level to ppb level). 6 However, the degradation of pollutants present in real wastewater matrices containing various other materials (such as natural organic matters, inorganic salts, fatty compounds, surfactants and many other things) used to be very difficult in comparison to water matrices devoid of such materials especially during heterogeneous photocatalysis based AOPs.…”

“…Moreover, poor dispersion and shielding/hindering of heterogeneous catalyst by other compounds may also cause a significant reduction in the degradation efficiency of the heterogeneous photocatalysis. Since, there are conjugate pros and cons of various established AOPs (Table S1), 2,4,[7][8][9][10][11] the sustainable development of the existing AOPs and the evolution of novel AOPs have become an indispensable necessity. These developments can provide additional options to choose and opt for a more suitable, economic and versatile AOP.…”