Water Reclamation Research Articles

A novel framework for integrative assessment of water balance health in China

Existing studies on water resource issues focus on water scarcity while largely lacking an integrative water balance health assessment and ignoring the combined impacts of water quality, water transfer, and unconventional water resources on water balance. Here, we proposed a novel framework for assessing regional water balance health considering three dimensions of water problems about imbalances: water scarcity, water inequality, and systems incoordination. This paper first quantified the levels of water balance health at multiple geographic and temporal scales in China, and then investigated the critical components and the impacts of improved surface water quality, inter-basin water transfer, and unconventional water use on the local water balance health. Results showed that China was under an unhealthy water balance due to multiple imbalances based on the annual average assessments during 2014–2018. More than 45% of the national population (∼615 million people) was affected by an unhealthy water balance. Hotspots with unhealthy water balance exhibited spatial heterogeneity and temporal variability, with Northern China experiencing unhealthy water balance throughout the year, while Southern China usually faced this issue during the winter. Unhealthy water balance in Northern China was primarily driven by water scarcity, while in the west of the Hu-Huanyong Line, water inequality exacerbated the situation. Southeastern China faced systems incoordination, particularly vulnerable during extreme events, such as severe droughts. More than 400 and 150 million people benefited significantly from improved surface water quality and inter-basin water transfer, respectively, relieving unhealthy water balance. However, the effectiveness of unconventional water use was found to be limited. This study contributed to a better understanding of water balance health and facilitated the development of policies for integrated water resources management in China.

Flow-electrode capacitive deionization (FCDI) with microfiltration membranes for water reclamation from highly saline and dye-polluted wastewater

Textile wastewater, in addition to being highly polluted by organics like dyes, contains large amounts of salts, e.g., ≈10gL−1, that need to be removed before discharged to the environment or reused. This work introduces a new FCDI process that uses microfiltration membranes to desalinate and decolor synthetic textile wastewater. Synthetic wastewater simulates the characteristics of real Indian textile wastewater, containing a mixture of different salts (NaCl, Na2SO4, NaHCO3), with a total concentration of 6.9gL−1, and tartrazine (MW =534.3gmol−1) as the large organic pollutant model, with a concentration of 2.1gL−1. FCDI modules with different membrane configurations, including microfiltration membranes (MF), are investigated, giving insights into the desalination and dye removal efficiencies under steady-state operation. At wastewater flow rates below 0.08mLmin−1, the conductivity of treated water reaches 0.2mScm−1, with a tartrazine concentration below 50mgL−1, fulfilling the requirement for water reuse in textile industries. This work reveals the potential of the FCDI process for both desalination and organics removal that can be applied to a wide range of wastewater streams.

Investigation of Biosand Filter (BSF) on the Treatment Performance of Industrial Latex Wastewater

Biosand Filters (BSF) has great potential to improve the water quality. BSF is used extensively in the treatment of drinking water in rural areas because it is affordable, simple to use, and has a high removal efficiency. This study used actual latex effluent to examine the effectiveness of SBR. The growth of the biolayer in the BSF is also observed. This study analyzes consistent and stable results for COD, DO and NH4-N+. With removal performance ranging from 87 % to 99 %. DO value for BSF varied from lowest value of 1.5 mg/L to 8mg/L. Overall, the BSF was capable of producing treated water for water reclamation.

Per- and poly-fluoroalkyl substances removal in multi-barrier advanced water purification system for indirect potable reuse.

The study evaluated the removal efficacy of per- and poly-fluoroalkyl substances (PFAS) across various advanced water treatment (AWT) processes in a field-scale AWT train using secondary effluent samples from a full-scale water reclamation facility (WRF). Samples collected from April to October 2020 revealed PFCAs as the dominant PFAS compounds in the WRF secondary effluent, with PFPeA having the highest average concentration and PFSAs in notably lower amounts. Temporal fluctuations in total PFAS concentrations peaked in September 2020, which may reflect the seasonality in PFAS discharges related to applications like AFFFs and pesticides. In assessing AWT processes, coagulation-flocculation-clarification-filtration system showed no notable PFAS reduction, while ozonation resulted in elevated PFBS and PFBA concentrations. Biological activated carbon (BAC) filtration effectively removed long-chain PFAS like PFOS and PFHxS but saw increased concentrations of short-chain PFAS post-treatment. Granular activated carbon (GAC) filtration was the most effective treatment, reducing all PFSAs below the detection limits and significantly decreasing most PFCAs, though short-chain PFCAs persisted. UV treatment did not remove short-chain PFCAs such as PFBA, PFPeA, and PFHxA. The findings highlight the efficacy of AWT processes like GAC in PFAS reduction for potable reuse, but also underscore the challenge presented by short-chain PFAS, emphasizing the need for tailored treatment strategies. PRACTITIONER POINTS: Secondary effluents showed higher concentrations of PFCAs compared to PFSAs. Advanced water treatment effectively removes long-chain PFAS but not short-chain. Ozonation may contribute to formation of short-chain PFAS. BAC is less effective on short-chain PFAS, requiring further GAC treatment.

Simultaneous Wastewater Treatment and Resources Recovery by Forward Osmosis Coupled with Microbial Fuel Cell: A Review.

Osmotic microbial fuel cells (OsMFCs) with the abilities to simultaneously treat wastewater, produce clean water, and electricity provided a novel approach for the application of microbial fuel cell (MFC) and forward osmosis (FO). This synergistic merging of functions significantly improved the performances of OsMFCs. Nonetheless, despite their promising potential, OsMFCs currently receive inadequate attention in wastewater treatment, water reclamation, and energy recovery. In this review, we delved into the cooperation mechanisms between the MFC and the FO. MFC facilitates the FO process by promoting water flux, reducing reverse solute flux (RSF), and degrading contaminants in the feed solution (FS). Moreover, the water flux based on the FO principle contributed to MFC's electricity generation capability. Furthermore, we summarized the potential roles of OsMFCs in resource recovery, including nutrient, energy, and water recovery, and identified the key factors, such as configurations, FO membranes, and draw solutions (DS). We prospected the practical applications of OsMFCs in the future, including their capabilities to remove emerging pollutants. Finally, we also highlighted the existing challenges in membrane fouling, system expansion, and RSF. We hope this review serves as a useful guide for the practical implementation of OsMFCs.

Feasibility of utilizing recycled drainage water in agriculture using an analytical network process (ANP) and geographic information system (GIS)

AbstractUtilizing unconventional water for sustainable agriculture is a multi‐criteria process. Decision‐making in such problems is based on finding the value of various criteria using advanced methods, for example the analytic network process (ANP). ANP is usually preferred in cases where the criteria are not independent and have intra‐/intergroup relationships. Considering techno‐economic and environmental criteria, the ANP structure was used in this study to investigate the feasibility of utilizing Chapaghli drainage water in western Golestan Province, Iran, for cultivating tolerant and semi‐tolerant crops, including canola, barley, cotton and wheat, using GIS software. Irrigation water availability, techno‐economic distance and land suitability for cultivation were selected as techno‐economic criteria, while irrigation water quality, soil, plant sensitivity and aquifer vulnerability were selected as environmental criteria. The results show that canola is the best crop for cultivation with Chapaghli drainage water. This study provides a reliable decision‐making infrastructure related to the recycling of drainage water for various cultivars in an area where environmental hazards are minimized.

IoT-based data and analytic hierarchy process to map groundwater recharge with stormwater.

The sustainable management of groundwater resources in developing countries is often challenging due to limited measurement and monitoring infrastructure to collect data necessary for decision support. To make a contribution towards addressing these challenges, this study investigated the use of Internet of Things (IoT) technology and low-cost sensors to collect the required groundwater-level data and develop a model to map the recharge potential with stormwater. The study focused on two stormwater ponds located in a highly urbanised area in Cape Town, South Africa. A combination of Geographic Information System and analytic hierarchy process was integrated to generate a groundwater recharge potential zone map of the study area. The IoT-based data were used to develop and calibrate a numerical groundwater model in MODFLOW. The study determined that retrofitted stormwater ponds are potential groundwater augmentation zones and can provide opportunity for stormwater recharge in urban areas. Overall, this study highlights the potential of IoT to collect hydrogeological data with low-cost sensors. Data can be collected at high temporal resolution, and the spatial scale can be increased due to availability of low-cost sensors.

FLOT-ART: An integrated plant optimization tool for the flotation of copper and copper–gold ores

Conventional flotation plant optimization procedures for copper and copper–gold ores have served the industry well over decades. But with the present trend in declining ore grades along with increase in metallurgical complexity, many flotation operations are experiencing significant challenges in sustaining design or operational budgeted recovery and concentrate quality targets. The need to use non-conventional water sources like brackish, sea water, and recycled process water has exacerbated the problem. Also with the emergence of various large mechanical cells and new non-mechanical flotation technologies, the ongoing use of traditional plant operational strategies is further adding to the challenges.This paper discusses an integrated plant optimization tool for the flotation of complex copper and copper–gold ores in addressing the present challenges, branded as FLOT-ART (Flotation Advanced Recovery Technology). This includes a cohesive flotation plant optimization approach starting with a mineral surface preparation step in grinding followed by advanced mineral-specific electrochemistry and cell hydrodynamics based circuit operation. This approach then allows an ore-specific grade-recovery control strategy for optimum flotation performance. This development is based on extensive greenfield projects, brownfield plant expansion studies along with operational optimization programs involving bench and plant campaigns. Principles of the FLOT-ART optimization system will be presented in this paper along with some commercial applications in the flotation of copper and copper–gold ores.

Exploring China's water scarcity incorporating surface water quality and multiple existing solutions

Water scarcity has threatened the sustainability of human life, ecosystem evolution, and socio-economic development. However, previous studies have often lacked a comprehensive consideration of the impact of water quality and existing solutions, such as inter-basin water transfer and unconventional water resources, on water scarcity. In this paper, an improved approach was proposed to quantify water scarcity levels by comprehensively considering surface water quality and multiple solutions. China's water scarcity was first assessed at a high spatial resolution on a monthly basis over the 5-year period from 2014 to 2018. Then, the driving factors including water quality and solutions were identified by a geographic detector model. Finally, an in-depth investigation was conducted to unravel the effects of water quantity solutions (i.e., inter-basin water transfer and unconventional water use), and water quality solutions (i.e., improving surface water quality) on alleviating water scarcity. Based on monthly assessments considering water quality and multiple existing solutions, the results showed that over half of the national population (∼777 million) faced water scarcity for at least one month of the year. Agricultural water use and inadequate water quality were the main driving factors responsible for China's water scarcity. Over four-fifths of the national population (∼1.10 billion) could benefit from alleviated water scarcity through a combination of water quantity and quality solutions. However, the existing solutions considered were insufficient to completely resolve water scarcity in China, especially in Northern China, persisting as a challenging issue. The results obtained from this study provided a better understanding of China's water scarcity, which could contribute to guiding future efforts aimed at alleviating water scarcity and ensuring water security in China.

A sunflower-pith-based robust and efficient evaporator with enclosed cellular structure and ultralow vaporization enthalpy for round-the-clock steam generation

Solar interfacial evaporation (SIE) is a promising method to generate freshwater from unconventional water resources. Using hydrogel materials to activate water molecules has been demonstrated as a facile way to achieve high SIE performance. However, as for hydrogel and hydrogel-analogous evaporators, there is a trade-off between SIE performance and mechanical property due to their high water content and porous structure. Herein, we demonstrate a low-cost and robust sunflower-pith-based hydrogel-like evaporator by simple dip-coating and soaking process. The rigid cellular framework and water encapsulated inside endow this evaporator with excellent compressive strength, which achieves 400.3 ± 64.1 KPa at compressive strain of 80 %. In the meantime, natural ultralow water vaporization enthalpy and ability to capture thermal energy from surroundings enable this evaporator to achieve an outstanding water evaporation rate of 3.39 kg·m−2·h−1 with an energy efficiency of 100.2 % under 1 sun. Moreover, this evaporator exhibits a potential for round-the-clock operation since its evaporation rate can reach 1.14 kg·m−2·h−1 in dark. After introducing artificial open channels, this evaporator shows remarkable stability and durability even for 20 wt% brine. This work provides a sustainable choice for efficient desalination and freshwater production, and offers a guideline for the bionic design of SIE materials.

Tackling climate change through wastewater reuse in agriculture: A prioritization methodology

Water shortages, exacerbated by climate change, are posing a major global challenge, particularly impacting the agricultural sector. A growing interest is raised towards reclaimed wastewater (RWW) as an alternative irrigation source, capable of exploiting also the nutrient content through the fertigation practice. However, a prioritization methodology for selecting the most appropriate wastewater treatment plants (WWTPs) for implementing direct RWW reuse is currently missing. Such prioritization would benefit water utilities, often managing several WWTPs, and policymakers in optimizing economic asset allocation. In this work, a prioritization framework is proposed to evaluate WWTPs' suitability for implementing direct RWW reuse considering both WWTP and surrounding territory characteristics. This procedure consists of four key steps. Firstly, a techno-economic model was developed, in which monthly mass balances on water and nutrients are solved by matching crop requirements, rainfall conditions, and effluent characteristics. Economic suitability was quantified considering economic benefits due to savings in freshwater resource, mineral fertilizers and avoided greenhouse gases emissions, but also losses in crop yield due to RWW salinity content. Secondly, a classification procedure was coded to select representative WWTPs among a set of WWTPs, based on their size, presence of nutrient removal processes, and type of crops in their surroundings. The techno-economic model was then applied to these selected WWTPs. Thirdly, input parameters' relevance in determining WWTP suitability for RWW reuse was ranked. Finally, scenario analyses were conducted to study the influence of rainfall patterns and nutrient treatment removal on the RWW reuse feasibility. The type of crops surrounding the WWTPs and RWW salinity content resulted to be crucial elements in determining WWTPs suitability for RWW reuse implementation. The proposed methodology proved to be an effective support tool for policymakers and water utilities to assess the techno-economic feasibility of direct RWW reuse, generalizing results to several combinations of WWTPs and crops.

Nano revolution: pioneering the future of water reclamation with micro-/nano-robots

Future of micro-/nano-robots in water reclamation.

Natural phytomelioration of the coastal water zone of man-made reservoirs in mining areas

Coal mine waste heaps are technogenic hazards that have been polluting the air, surface and groundwater, soil for years. At the UN Climate Conference COP26, held in November 2021 in Glasgow (Scotland), Ukraine and developed countries committed to carbon neutrality by 2060 and to abandoning fossil fuels by 2035. One of the largest technogenic factors in waste heaps is subterranean wastewater. Wastewater accumulates in the man-made reservoirs at the foot of the coal mine waste heaps. In our case, one of the most effective means of improving coal mining regions’ environmental quality is phytomelioration, particularly coastal and water reclamation. The article presents the results of research within the Lviv-Volyn coal basin (Ukraine). During the study of natural phytomelioration processes in the coastal zone of man-made reservoirs, it was found that vegetation develops within four zones: I – underwater vegetation that is permanently covered by water (22% of the total number of species); II – vegetation of fluctuating water levels (32%); III – vegetation of the coastal zone (14%); IV – vegetation above the coastal zone (32%). The species composition includes 37 species belonging to 20 families. By family composition, the largest share of the species composition belongs to representatives of Asteraceae (15%), Poaceae (11%), Potamogetonaceae (8%). The study of the species composition and family spectrum of coastal and aquatic phytomelioration processes is important in implementing environmental protection and ecological measures to improve the quality of the environment of technogenically affected coal mining areas.

Superior single- and multi-component siloxane removal from water using a faulted silica DON zeolite adsorbent

Pure porous silica zeolite adsorbents with framework surface faults, in the form of siloxy groups, are selective toward single- or multi-component linear siloxanes for removal from water.

Microwave-assisted synthesis of triazine covalent organic frameworks via friedel-crafts reaction for use in treating brackish Water

Water scarcity is becoming an ever-growing problem in society. This is all due to the rapid increase in human population, harsh changes in the weather climate. New approaches for treating and recycling brine water into freshwater instead of discharging are needed, significantly large reduction in energy usage and decreasing harmful impact to the environment must be achieved in brine recovery. This study aims to introduced green technology into the reclamation of brine water by use of covalent organic frameworks (COFs) materials which will be used as part of a novel triazine-based COFs material which can be used as a nanomembrane for desalination of brine water from water treatment plants at Umgeni Water. Current technological approaches used are inefficient and unsuitable in 3rd world, developing countries including the republic of South Africa. This work focuses on a microwave-assisted synthesis involving Friedel Crafts reaction between monomers to yield a product of a triazine-based covalent organic frameworks (COFs) membranes. To confirm the products high resolution transmission electron microscopy (HRTEM), carbon NMR (13C NMR) with peaks at chemical shifts of 131, 143 and 172 ppm respectively. Fourier-transform infrared spectroscopy (FTIR) was employed and showed N-H stretches at a region of 3396 to 3050 cm-1. The COFs that were successfully synthesised are going to be incorporated on a polymeric substrate to fabricate a nanofiltration membrane and applied for nanofiltration or ultrafiltration purposes.

Modeling the operating modes of solar power plants for powering reclamation plants for water treatment and wastewater reuse

Modeling the operating modes of solar power plants for powering reclamation plants for water treatment and wastewater reuse

Effects of Rhizosphere Microbial Composition on the Growth of Cajanus cajan in Coal Gangue Reclaimed Soil

This study aimed to investigate the microbial diversity and functions of Cajanus cajan root systems planted in plateau waste dumps collected in Liupanshui City, Guizhou Province, China. The gangue dump (1,390 m above sea level) in the Guizhou Plateau was covered with soil and planted with YN and JX C. cajan. After 1 year, the C. cajan root system was collected, and high-throughput sequencing was used to examine its bacterial and fungal biodiversity. The unclassified_f_Enterobacteriaceae and Cedecea were the most abundant genera. Venn and heatmap analyses revealed differences in the dominant species Lactococcus and Fusarium in the rhizosphere of C. cajan varieties. In JX and YN, Pseudoarthrobacter is a unique genus of bacteria; in JX, Robillarda is a unique genus of fungi; and in YN, Scytalidium is a unique genus of fungi. Endophytic fungi mainly play the roles of saprotroph, plant pathogen, and endophyte. Among the bacterial properties, L-arabinose isomerase and adenosine triphosphatase were the most abundant in all samples, while chitinase, catalase, and laccase played important roles in photosynthesis and the degradation of lignin, chitin, and chitosan. Our findings may guide the selection of reclamation plants and strategies for the mitigation and restriction of heavy metals in soil.

基于多元线性回归的中水回用技术营销推广研究

基于多元线性回归的中水回用技术营销推广研究

Nanoscience and nanotechnology for water remediation: an earnest hope toward sustainability.

Water pollution and the global freshwater crisis are the most alarming concerns of the 21st century, as they threaten the sustainability and ecological balance of the environment. The growth of global population, climate change, and expansion of industrial processes are the main causes of these issues. Therefore, effective remediation of polluted water by means of detoxification and purification is of paramount importance. To this end, nanoscience and nanotechnology have emerged as viable options that hold tremendous potential toward the advancement of wastewater treatment methods to enhance treatment efficiency along with augmenting water supply via utilization of unconventional water sources. Materials at the nano level have shown great promise toward water treatment applications owing to their unique physicochemical properties. In this focus article, we highlight the role of new fundamental properties at the nano scale and material properties that are drastically increased due to the nano dimension (e.g. volume-surface ratio) and highlight their impact and potential toward water treatment. We identify and discuss how nano-properties could improve the three main domains of water remediation: the identification of pollutants, their adsorption and catalytic degradation. After discussing all the beneficial aspects we further discuss the key challenges associated with nanomaterials for water treatment. Looking at the current state-of-the-art, the potential as well as the challenges of nanomaterials, we believe that in the future we will see a significant impact of these materials on many water remediation strategies.

Reclamation of impacted urban phreatic water through nanofiltration technology: Insight on natural organic matter removal by fluorescence spectroscopy

Nanofiltration (NF) is a promising technology called to play a relevant role in water reclamation, which lies in the core of circular economy in the water sector. The aim of this study was to assess two aromatic polyamide-based NF membranes (the looser NF270 and the tighter NF90 ones) for the treatment of urban impacted phreatic water. The focus was centred on the removal of dissolved inorganic and organic solutes and on the differences observed between solutes. Membrane ions rejection was modelled by the Solution-Electro-Diffusion Film Model (SEDFM). DOC was tracked by Fluorescence Excitation-Emission Matrices (FEEM) coupled to Parallel Factor Analysis (PARAFAC) to get insight into the character of DOC rejected by or permeated through the membranes. Results showed that the NF90 membrane systematically achieved upper values in the rejection of ions than the looser NF270 one. Variations between ions could be interpreted by the mechanisms ruling their rejection, i.e. Donnan and dielectric exclusion phenomena. Experimental rejections were also satisfactorily fit by the SEDFM, indicating that that the presence of DOC in the phreatic water did affect modelling of ions transport through the membranes. DOC was rejected at very high percentages (>90%) by both membranes, but FEEM-PARAFAC analysis revealed that humic- and tryptophan- like components were more rejected (>90% for both membranes) than tyrosine-like compounds (45% for NF270 and 57% for NF90). The finding is of relevance from a point of view of disinfection practices, as it has been observed that humic-like substances are strongly correlated with DBPs formation.