Advancements in Nanoenabled Membrane Distillation for a Sustainable Water-Energy-Environment Nexus.

The emergence of nano innovations in membrane distillation (MD) has garnered increasing scientific interest. This enables the exploration of state-of-the-art nano-enabled MD membranes with desirable properties, which significantly improve the efficiency and reliability of the MD process and open up opportunities for achieving a sustainable water-energy-environment (WEE) nexus. This comprehensive review provides broad coverage and in-depth analysis of recent innovations in nano-enabled MD membranes, focusing on their role in achieving desirable properties, such as strong liquid-repellence, high resistance to scaling, fouling, and wetting, as well as efficient self-heating and self-cleaning functionalities. The recent developments in nano-enhanced photothermal-catalytic applications for water-energy co-generation within a single MD system are also discussed. Furthermore, the bottlenecks are identified that impede the scale-up of nanoenhanced MD membranes and a future roadmap is proposed for their sustainable commercialiation. This holistic overview is expected to inspire future research and development efforts to fully harness the potential of nano-enabled MD membranes to achieve sustainable integration of water, energy, and the environment.

Nanobubbles in water and wastewater treatment systems: Small bubbles making big difference.

Since the discovery of nanobubbles (NBs) in 1994, NBs have been attracting growing attention for their fascinating properties and have been studied for application in various environmental fields, including water and wastewater treatment. However, despite the intensive research efforts on NBs' fundamental properties, especially in the past five years, controversies and disagreements in the published literature have hindered their practical implementation. So far, reviews of NB research have mainly focused on NBs' role in specific treatment processes or general applications, highlighting proof-of-concept and success stories primarily at the laboratory scale. As such, there lacks a rigorous review that authenticates NBs' potential beyond the bench scale. This review aims to provide a comprehensive and up-to-date analysis of the recent progress in NB research in the field of water and wastewater treatment at different scales, along with identifying and discussing the challenges and prospects of the technology. Herein, we systematically analyze (1) the fundamental properties of NBs and their relevancy to water treatment processes, (2) recent advances in NB applications for various treatment processes beyond the lab scale, including over 20 pilot and full-scale case studies, (3) a preliminary economic consideration of NB-integrated treatment processes (the case of NB-flotation), and (4) existing controversies in NBs research and the outlook for future research. This review is organized with the aim to provide readers with a step-by-step understanding of the subject matter while highlighting key insights as well as knowledge gaps requiring research to advance the use of NBs in the wastewater treatment industry.

China Sponge City database development and urban runoff source control facility configuration comparison between China and the US.

Urban runoff source control facilities (URSCFs) are important parts of Sponge City (SC) by controlling urban flooding, restoring eco-balance, and enhancing city resilience. To evaluate the performance of URSCF, one needs to summarize and analyze the past SC construction and operation data. Previous studies however are predominately engineering practice studies. There lacks localized reference datasets to quantitatively evaluate the performance and guide public policy development for SC. Therefore, it is imperative to develop a database, which would summarize data obtained through the already completed pilot sponge cities, and provide a reference for future URSCFs planning and construction. This study makes a zero to one breakthrough by establishing a SC database using New Orleans method. Then statistical results of facility type, size, and costs information for 30 pilot sponge cities have been summarized and analyzed. The URSCFs type distribution statistical results show that bioretention, permeable pavement, detention cell, grassed swale and constructed wetland are the top five most constructed facilities in China. The cost statistical results display that the range of facility cost collected is usually larger than the range given by the reference value, which may attribute to the variation in material cost, labor cost and design parameters in different cities. To check the similarities and differences of URSCFs parameters between China and the US. A configuration parameters comparison of URSCFs has been conducted. Bioretention is taken as an exampl. Comparison results show that factors such as climate type, geographical environment, and socio-economic conditions will affect the configuration parameters of URSCFs. The groundwater depth and designed rainfall intensity are mainly influenced by local climate and geographical conditions. Surface area is influenced by local socio-economic conditions. The thickness of the covering layer and drainage layer are not affected by geographic location. The service area ratio, water storage depth and planting soil layer thickness are significantly different between China and the US.

Prolonged lifetime of biological activated carbon filters through enhanced biodegradation of melamine.

Micropollutants can be removed in Biological Activated Carbon (BAC) filters through biodegradation, besides adsorption, when the conditions are favorable. In the present study, we build upon previous work on melamine biodegradation and activated carbon regeneration in batch experiments and assess the efficiency of this process in continuous flow lab-scale BAC filters. Melamine is frequently detected at low concentrations in surface water and is used here as a model micropollutant. BAC filters were inoculated with melamine degrading biomass and the contribution of biodegradation to melamine removal was assessed. Furthermore, we tested the effect of an additional carbon source (methanol) and the effect of contact time on melamine removal efficiency. We demonstrate that inoculation of activated carbon filters with melamine degrading biomass increases melamine removal efficiency by at least 25%. When an additional carbon source (methanol) is supplied, melamine removal is almost complete (up to 99%). Finally, through a nitrogen mass balance, we demonstrate that around 60% of the previously adsorbed melamine desorbs from the BAC surface when biodegradation rates in the liquid phase increase. Melamine desorption resulted in a partial recovery of the adsorption capacity.