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This study explored the impact of eco-friendly polydopamine (PDA) coated ZnFe2O4 nanocomposites (PDA@ZnFe2O4 NCs) as nanofillers to fabricate a new class of polyethersulfone (PES) hybrid ultrafiltration (UF) membranes for wastewater treatment applications. The hybrid UF membrane was prepared by incorporating PDA@ZnFe2O4 NCs into PES via the non-solvent induced phase separation (NIPS) process. The PDA@ZnFe2O4 NC was characterized by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Additionally, the morphology and performance of the prepared hybrid membranes were characterized by SEM, contact angle, surface charge, and thermogravimetric analysis (TGA). The incorporation of PDA@ZnFe2O4 NC into the PES membrane affects the porosity, mean pore radius, hydrophilicity, and thermal stability of the developed hybrid membranes. The pure water flux of the PES hybrid membrane with 4 wt% PDA@ZnFe2O4 reached ∼687 L/m2 h, which is about 188% higher than that of the pristine PES membrane. The performance of the PES/ PDA@ZnFe2O4ultrafiltration hybrid membrane was also investigated using humic acid (HA) foulant and oil/water emulsion individually. Compared to the pristine PES and PES/ZnFe2O4 membranes, the developed hybrid membranes showed enhanced permeability and HA foulant removal. HA's removal efficiency has improved from ∼65% in the pristine PES membrane to ∼94% in the 4 wt% PDA@ZnFe2O4 hybrid membrane. The abundant functional groups on the PDA@ZnFe2O4 NC surface also enhanced the separation of the oil/water emulsion (96%). In both the HA and oil/water emulsion separation tests, the flux recovery ratio (FRR) and reversible fouling ratio (Rr) were also significantly improved, suggesting that the PES/PDA@ZnFe2O4 membrane was a very promising candidate for HA removal and treatment of oily wastewater.

This review paper aims to identify the main sources of carbon dioxide (CO2) emissions from wastewater treatment plants (WWTPs) and highlights the technologies developed for CO2 capture in this milieu. CO2 is emitted in all the operational units of conventional WWTPs and even after the disposal of treated effluents and sludges. CO2 emissions from wastewater can be captured or mitigated by several technologies such as the production of biochar from sludge, the application of constructed wetlands (CWs), the treatment of wastewater in microbial electrochemical processes (microbial electrosynthesis, MES; microbial electrolytic carbon capture, MECC; in microbial carbon capture, MCC), and via microalgal cultivation. Sludge-to-biochar and CW systems showed a high cost-effectiveness in the capture of CO2, while MES, MECC, MCC technologies, and microalgal cultivation offered efficient capture of CO2 with associate production of value-added by-products. At the state-of-the-art, these technologies, utilized for carbon capture and utilization from wastewater, require more research for further configuration, development and cost-effectiveness. Moreover, the integration of these technologies has a potential internal rate of return (IRR) that could equate the operation or provide additional revenue to wastewater management. In the context of circular economy, these carbon capture technologies will pave the way for new sustainable concepts of WWTPs, as an essential element for the mitigation of climate change fostering the transition to a decarbonised economy.

Waterborne enteric viruses that are commonly found in wastewater can cause several sporadic cases of diseases and outbreaks as a result of water or food contamination. Their detection, quantification, and effective removal from wastewater is of great importance. In this context, this review paper describes the different types of waterborne enteric viruses that are frequently found in wastewater and evaluated the various techniques developed for their concentration and detection. Furthermore, the review comprehensively discusses the different traditional, membrane filtration, and advanced/hybrid technologies used in the removal of these viruses. Over the past few decades, several efforts have been made to employ the membrane-based and other hybrid technologies to eliminate waterborne enteric viruses effectively. In this regard, technologies, such as microfiltration (MF), ultrafiltration (UF), membrane bioreactor (MBR) among others, have been widely applied. The major concerns related to these technologies are in the factors that would have an impact on membrane performance in terms of viruses' removal efficiency and sustainable operation. The advantages, limitations, and other related factors of the application of these technologies will be discussed in this review. Lastly, Light will be shed on the future perspectives and research opportunities for the widespread implementation of these technologies in the treatment of viruses-rich wastewater., The authors appreciate the support provided by the Center for Membranes and Advanced Water Technology (CMAT) at Khalifa University of Science and Technology (Abu Dhabi, UAE) (Award No. RC2-2018-009).

Many emerging contaminants (ECs) are not currently removed by conventional water treatment methods and consequently, often reach the aquatic environment. In the absence of proper management strategies, ECs can accumulate in water bodies, which poses potential environmental and health risks. This paper critically reviews, for the first time, the reported occurrence and treatment of ECs in the Middle Eastern and North Africa (MENA) region. The paper also provides recommendations to properly manage EC risks. In the MENA region, pharmaceuticals and personal care products (PPCPs) have been detected in surface water, seawater, groundwater, and wastewater treatment plants. A focus on surface water in the published literature suggests that studies are skewed towards worldwide trends, whereas studies on ECs in seawater are of great importance in the study region. The types of PPCPs detected in the MENA region vary, but anti-inflammatories and antibiotics dominate. In comparison, microplastics have mainly been studied in surface waters and seawater with much less focus on drinking water. The majority of microplastics in the region are secondary types resulting from the degradation of larger plastic debris; polyethylene (PE) and polypropylene (PP) fibers are the most frequently detected polymers, which are indicative of local anthropogenic sources. Research progress on ECs varies between countries, having received more attention in Iran and Tunisia. Most MENA countries have now begun monitoring water bodies for ECs; however, studies are still lacking in some countries including Sudan, Djibouti, Syria, Ethiopia, and Bahrain. Based on this review, critical knowledge gaps and research needs are identified. Countries in the MENA region require further research on a broader range of EC types. Overall, water pollution due to the use and release of ECs can be tackled by improving public awareness, public campaigns, government intervention, and advanced monitoring and treatment methods.

In this study, phase-inverted polyethersulfone (PES)-maghemite (γ-Fe2O3) composite membranes were fabricated and tested for oil-water separation. The performance of five different composite membranes with various loadings of γ-Fe2O3 (0.25, 0.50, 0.75, and 1.00 wt.%) in terms of water flux, flux recovery, and oil rejection was investigated. The surface morphology, crystallinity, and functionalities of the membranes were characterized via scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and Fourier-transform infrared (FT-IR). Furthermore, the porosity, pore size, water contact angle, and underwater oil contact angle of the composite membranes were examined. Results showed that the pristine PES membrane reported a pure water flux of 1242 ± 12 L/m2h (LMH) compared to 1323 ± 27 LMH for the 0.25 wt.% PES/γ-Fe2O3 membrane. Additionally, 56 and 23 % flux recovery ratio (FRR) were reported for the PES/γ-Fe2O3 and the pristine PES membrane, respectively. Also, the removal efficiency has increased from 39.2 % in the PES membrane to 81.7 % in the 1.00 wt.% PES/γ-Fe2O3 composite membrane. Two phenomena played a role in the removal trends, namely size exclusion and electrostatic repulsion forces. The developed membranes exhibited significant application potential for the removal of oil from wastewater.