Various Types Of Wastewater Research Articles

The role of smart technologies in wastewater-based epidemiology

This article explores the role of smart technologies in advancing Wastewater-based epidemiology (WBE) for enhanced disease surveillance. Disease surveillance is crucial for monitoring and controlling infectious diseases, and WBE provides a complementary approach by analyzing wastewater to identify and track pathogens. During the COVID-19 pandemic, WBE has been successfully used to detect and monitor SARS-CoV-2 in various types of wastewater, providing early warning of outbreaks and identifying emerging hotspots. However, WBE faces challenges such as the need for specialized equipment and sensitive methodologies. To overcome these limitations, biosensors have been developed, offering high sensitivity, specificity, and rapid results. Electrochemical biosensors are particularly promising for WBE due to their real-time connectivity, low-cost design, and wireless data collection, despite their limitations. Integration of smart sensors into the Internet of Things (IoT) enables seamless data integration and real-time monitoring. Furthermore, the widespread use of smartphones presents an opportunity to revolutionize smart diagnostics by leveraging their features for data analysis and communication.

Assessment of potential toxicological risk for public health of heavy metal iron in diverse wheat varieties irrigated with various types of waste water in South Asian country

Various field trials were performed at different locations of Punjab, Pakistan to study the effect of trace metals on uptake of iron (Fe) and wheat productivity as well as the health risk assessment by ingestion of wheat grains grown with application of different irrigation sources. The experimental design was laid out in RCBD having four replications. Soil samples were taken before sowing of crop from 0 to 15 cm depth and Triticum astivum samples were taken after irrigation through different water treatments examined for pollution load index (PLI), bioaccumulation factor (BAF), translocation factor (TF), bioconcentration factor (BCF), daily intake of metal (DIM) and health risk index (HRI) parameters. Fe concentrations in soil from five districts where wheat types watered with 3 different supplies ranged from 30.28 to 41.03 mg/kg and in grain sample ranged between 1.36 and 6.74 mg/kg. All the samples had DIM values of Fe were observed lower than standard tolerable limits and values of HRI less than 1 which indicates that there is no Fe toxicity due to utilization of wheat grains.

Evolution of Membrane Surface Properties for Membrane Distillation: A Mini Review

To date, the membrane development for membrane distillation (MD) application is growing in line with the increasing volume of various types of wastewaters discharged into environment. MD is a liquid-vapor separation process and a hydrophobic membrane is used to retain the liquid. Theoretically, the hydrophobic membrane can achieve 100% rejection of non-volatile components that dissolved in feed liquids. As a result, MD has received significant attention in water recovery from saline water as well as wastewaters. Nevertheless, in addition to the scaling problem due to salts, the hydrophobicity property of membrane becomes a concern when dealing with challenging wastewaters which contain various types of low surface tension components such as oils, grease, alcohols, organics and surfactants. The membrane pore wetting due to salts deposition fouling and low surface tension components subsequently reduces the flux and even fails the liquid-vapor separation process. This article briefly discusses the transformation of MD membrane from hydrophobic to superhydrophobic and omniphobic which purposely to enhance the flux and eliminate the membrane pore wetting.

Trends and perspectives of microbial electrolysis cell technology for ultimate green hydrogen production

Currently, gray hydrogen and blue hydrogen are widely recognized as renewable energy, but in reality, they are made from fossil fuels. The most important task to achieve the hydrogen-based society is the development of economic green hydrogen production technology. Microbial electrolysis cell (MEC) is a next-generation energy-producing wastewater treatment technology that treats renewable organic wastewater and simultaneously produces the ultimate green hydrogen. For hydrogen production in MFC, it is necessary to input electrical energy into MEC. However, that energy is all covered by the energy produced by the MEC. Therefore, hydrogen production in MEC can be defined as the ultimate green hydrogen. This review contains an in-depth summary and analysis of the principles and feasibility of MEC technology, the composition and shape of MEC, electrode materials, and practical application cases in various types of wastewaters. Furthermore, compatibility and scalability with other environmental systems were reviewed at the pilot scale. Based on this, the technical limitations of MEC were diagnosed and future research directions for the practical application of MEC technology were suggested.

WAYS OF IMPROVING THE ENVIRONMENTAL SAFETY OF URBANIZED AREAS: TECHNOLOGIES AND INNOVATIONS

The paper describes a technique for identifying appropriate environmental technology options for populated areas. Based on the method of analysis of hierarchies (MAI), a methodical approach for determining the priority technologies of phytoremediation for the treatment of various types of wastewater from settlements has been developed. The developed approach makes it possible to involve experts in environmental, urban planning, social, and economic direction of municipal management bodies of a specific settlement, industrial, residential, and military facilities, where the construction of treatment facilities is planned, to justify decisions in the management of environmental safety of surface water bodies located near the specified settlements. According to the developed approach, criteria formulated as influencing groups of factors reflecting: input and output parameters of the cleaning system were proposed and used; circumstances that exist in the place where treatment facilities are planned to be built, and requirements that directly relate to phytoremediation technologies. Relevant experts, relying on various types of information (data of direct measurements, statistical and predictive estimates) on the specific purpose and location of treatment facilities, give their own judgments regarding the priority of the advantages of the specified criteria. Expert judgments are processed according to the formal procedure of the MAI, which is implemented on a computer, and is the basis for decision-making when choosing the priority technology of phytoremediation in specific conditions. The multi-criteria hierarchical structure of phytoremediation technology selection is represented by a sequence of actions that include the following stages: development of elements of a methodical approach; verification of the consistency of the proposed hierarchical structure for determining priority technologies based on the input data of several objects of settlements; obtaining data on the priority of phytoremediation technology for implementation on these objects. The advantages of the proposed methodical approach should include the possibility to link to a single algorithm for the justification of the required decision data that differ both in their content (ecological, biological in terms of higher aquatic plants, urban planning, social and economic) and in the form of presentation (data of direct measurements, statistical and predictive estimates). Keywords: environmental safety, system approach, technologies, tools and ecological and economic aspects of environmental protection activities, environmental quality, processing of eco-data, regulatory framework.

Sustainability and carbon neutralization trends in microalgae bioenergy production from wastewater treatment: A review

Reducing CO2 emissions using biomass is gaining popularity as an environmentally friendly strategy. Due to high growth rates, low production costs, and ability to withstand harsh conditions, microalgae have become quite popular. Microalgae may also undertake photosynthesis, converting CO2 and solar energy into sugar before becoming biomass, making them an excellent source of renewable and promising biofuels. CO2 sequestration and biofixation was utilized to compare the synthesis of biodiesel as a third-generation biofuel from various types of wastewater was also used as a source for the algal cultivation. This review article focuses on recent developments, research discoveries in the field of microalgal CO2 capture modification and the optimization of conversion efficiency. This review is intended to serve as a helpful and reference for the use of wastewater treatment with microalgae to collect CO2. The overarching objective of this study is to assist wastewater treatment systems in achieving carbon neutrality.

Corrosion Behaviour of Nodular Cast Iron Used for Rotor Manufacturing in Different Wastewaters

Submersible drainage sump pumps work in a highly corrosive environment, forming films with corrosive reaction products on the surface. Pump rotors are high-demand parts, so they are made of quality materials with good wear and corrosion resistance properties such as nodular graphite cast iron. This paper analyses the corrosion behaviour of cast iron used in the manufacture of rotors in three types of wastewaters, with variable pH. Nodular graphite cast iron samples were immersed in wastewater for 30, 60, and 90 days and tested by linear polarisation and electrochemical impedance spectroscopy (EIS). Also, the layers of reaction products formed on the surface of the material were analysed by SEM and EDS. The results showed that nodular cast-iron immersed in wastewater with acidic pH showed intense corrosion, the oxide layer formed on its surface is unstable. Also, the final structure of the product layer is that of a tri-layer with cations and anions absorbed from the corrosion media: the double-electric layer directly connected to the metal surface, an internal layer consisting of ferrous compounds and ferric compounds that control the diffusion of oxygen, an outer layer, and a compact crust of ferric compounds. The change in the pH of the wastewater has a major influence on the corrosion rate of the cast iron, which increases from 356.4 µm/year in DWW-1 (6.5 pH) to 1440 µm/year in DWW-2 (3 pH) and 1743 µm/year DWWW-3 (11 pH) respectively. As can be seen, the experimental study covers the problem of the corrosion behaviour of the pump rotor in various types of wastewaters this aspect is particularly important for the good use of wastewater pumps and to predict possible deviations for the operation of the equipment within the treatment plants.

Molecular engineering of biomass-derived hybrid hydrogels for solar water purification

Solar evaporation which ultilizes the sustainable solar energy for freshwater production from waste or saline water is one of the most attractive technologies to simultaneously address energy and freshwater crisis. Nevertheless, high energy consumption of water-vapor transformation greatly restricts the practical applications of solar-driven water purification. Herein, we report hybrid hydrogels formed by introducing biomass, starch, and carbon nanotube into hydrophilic polyvinyl alcohol in a cost-effective route, used as multifunctional evaporators. The interpenetrating network has good hydrophilicity, fast water transport and adjustable state of water molecules, which reduces the enthalpy of water vaporization to promote the evaporation process. Thus, the obtained hydrogel evaporator possesses an evaporation rate of 2.44 kg m−2h−1 with 95% efficiency under one-sun, and is capable of producing clean water from various types of wastewater, including salty, acidic, alkaline and organic polluted water, with long-term durability and stability. It also presents excellent antibacterial, salt resistance and self-cleaning capabilities, suitable for practical applications. More notably, with abundant OH groups from starch, the hybrid hydrogel can effectively adsorb heavy metal ions and organic dyes via formation of chelating and hydrogen bonds. Therefore, this work provides a new approach for portable and cost-effective solar-driven wastewater purification.

Statistical optimization for simultaneous removal of methyl red and production of fatty acid methyl\xa0esters using fresh alga Scenedesmus obliquus

Microalgae are a diverse group of microorganisms, the majority of which are photosynthetic in nature. Microalgae have different applications, the most important of which is the biological treatment of wastewater. Microalgae grow in various types of wastewater, such as wastewater polluted by Azo dyes, due to microalgae using wastewater as a culture medium, which contains many nutrients like nitrogen, phosphate, and carbon sources. Microalgae grow in various types of wastewater, such as wastewater polluted by Azo dyes, due to microalgae using wastewater as a culture medium, which contains many nutrients like nitrogen, phosphate, and carbon sources. So, microalgae are used for bioremediation of wastewater due to the efficiency of growing in wastewater and for the high production of lipids followed by trans-esterification to biodiesel. Face-centered central composite design (FCCCD) was used to determine the factors that have the most significant impact on the simultaneous decolorization of methyl red and lipid production by the fresh green alga Scenedesmus obliquus. The predicted results indicated that the alga decolorized 70.15% methyl red and produced 20.91% lipids by using 1 g/L nitrogen, an incubation time of 10 days, a pH of 8, and the concentration of methyl red is 17.65 mg/L. The dry biomasses of S. obliquus were also examined by SEM and FTIR before and after treatment with methyl red. SEM and FTIR showed that the properties of dry S. obliquus were altered after the biosorption of methyl red. According to GC–MS analysis of hexane extracts of S. obliquus, the lipid profile differed before and after methyl red decolorization. The results proved that it is possible to use S. obliquus to remove dyes and produce renewable fuels such as biodiesel. The novelty of this study is that this is the first time in which the effect of nitrogen concentrations in the medium used for algal growth on the removal of dye has been studied.

Development of electrocoagulation process for wastewater treatment: optimization by response surface methodology

Electrocoagulation (EC) is a process used by supply of electric current with sacrificial electrodes for the removal of pollutant from wastewater. The study was experimentally investigated taking into account various factors such as pH (3–7.5), current (0.03–0.09 A), distance between the electrodes (1–2 cm), electrolytic concentration (1–3 g/L), and electrolysis time (20–60 min) which is impact on the % removal efficiency of color, chemical oxygen demand (COD), turbidity and determination of energy consumption used for aluminum (Al) electrode used. The surface response design process based on the central composite design (CCD) has been used to optimize different operational parameters for treatment of hospital wastewater using EC process. The % color, COD and turbidity removal, and energy consumption under different conditions were predicted with the aid of a quadratic model, as were the significance and their interaction with independent variables assessed by analysis of variance (ANOVA). The optimal conditions were obtained through mathematical and statistical methods to reach maximum % color, COD, and turbidity removal with minimum energy consumption. The results showed that the maximum removal of color (92.30%), COD (95.28%), and turbidity (83.33%) were achieved at pH–7.5, current–0.09A, electrolytic concentration–3g/L, distance between electrodes–2 cm and reaction time 60 min. This means that, the process of EC can remove pollutants from various types of wastewaters and industrial effluent under the various operating parameters.

Harvesting biohydrogen from industrial wastewater: Production potential, pilot-scale bioreactors, commercialization status, techno-economics, and policy analysis

Herein, recent reports on hydrogen production from wastewater were comprehensively evaluated. There are numerous methods of biohydrogen production from various types of wastewater. Fermentation is one of the most promising methods of biohydrogen production from industrial wastewater owing to its ease of operation and rapid hydrogen production. The sequential dark/photo fermentation approach generated a maximum hydrogen yield (HY) of 7.1 mol H2/mol glucose with an estimated hydrogen production cost of 2.57 US $/kg and 2.83 US $/kg for dark and photo-fermentation, respectively. Pre-existing studies demonstrated that the successful implementation of pilot-scale fermentation bioreactors with a maximum hydrogen production rate (HPR) of 17 m3/m3·d, but HPR is negatively correlated with reactor volume; more pilot-scale studies using high-strength wastewater for optimum performance are needed. The current implementation and commercialization challenges during hydrogen production were also highlighted in this review. Furthermore, a literature survey revealed research gaps associated with optimum conditions for maximized biohydrogen yield. Numerous review studies in literature focus on biohydrogen potential from solid biowaste; nevertheless, a comprehensive review on biohydrogen from wastewater is still needed. The recommendations of this review are designed to facilitate researchers and policymakers in achieving sustainable development goals (SDGs), including clean water and sanitation (SDG 6), renewable energy (SDG 7), sustainable communities (SDG 11), and climate action (SDG 13).

The Historical Development of Constructed Wetlands for Wastewater Treatment

Constructed wetlands (CWs) for wastewater treatment are engineered systems that are designed and operated in order to use all natural processes involved in the removal of pollutants from wastewaters. CWs are designed to take advantage of many of the same processes that occur in natural wetlands, but do so within a more controlled environment. The basic classification is based on the presence/absence of wastewater on the wetland surface. The subsurface flow of CWs can be classified according to the direction of the flow to horizontal and vertical. The combination of various types of CWs is called hybrid CW. The CWs technology began in the 1950s in Germany, but the major extension across the world occurred during the 1990s and early 2000s. The early CWs in Germany were designed as hybrid CWs; however, during the 1970s and 1980s, horizontal subsurface flow CWs were mostly designed. The stricter limits for nitrogen, and especially ammonia, applied in Europe during the 1990s, brought more attention to vertical subsurface flow and hybrid systems. Constructed wetlands have been used to treat various types of wastewater, including sewage, industrial and agricultural wastewaters, various drainage and runoff waters and landfill leachate. Recently, more attention has also been paid to constructed treatment wetlands as part of a circular economy in the urban environments: it is clear that CWs are a good fit for the new concept of sponge cities.

Strategic Planning for Optimal Management of Different Types of Shale Gas Wastewater

This paper presents a mathematical programming approach for the strategic planning of managing wastewater generated by hydraulic fracturing operations in shale gas production. The proposed approach aims to achieve optimal selection of treatment, storage, and reuse activities. The approach also accounts for the variability of wastewater characteristics including the short-term flowback and transition water as well as the longer-term produced water. Because of the different compositions of the pollutants in the various types of wastewater, stream segregation is considered as an option. Furthermore, the model accounts for seasonal variabilities in freshwater availability. Economic and environmental objectives are considered. The economic objective function aims to determine the minimum total cost, which is composed of freshwater, treatment, storage, and transport costs. Credit is given for reused water. The environmental objective focuses on the reduction of freshwater requirements needed for the fracturing step. The proposed model determines trade-offs between cost and water consumption. A case study is presented, and the results show that it is possible to reduce up to 32.43% of freshwater consumed and to reuse up to 12.26% of the total wastewater from wells for fracturing needs.

Chromium Removal from Electroplating Wastewater Using Activated Coffee Husk Carbon

Chromium (Cr) is a heavy metal that has a serious environmental pollution problem. Electroplating wastewater contains high level of Cr that surpassed the acceptable environmental discharge standard limit in surface water bodies and causes aquatic ecosystem risks. Various studies have been conducted in Ethiopia on the removal of Cr from various types of wastewater; however, factual studies on the adaptability of cost-effective activated coffee husk carbon for the removal of Cr from electroplating wastewater are lacking. Thus, this study was conducted to evaluate the Cr adsorption efficiency of activated coffee husk carbon from electroplating wastewater at laboratory scale. The activated coffee husk carbon’s pH, electrical conductivity (EC), ash content, moisture content, bulk density, particle size, pore volume, porosity, volatile organic matter, carbon yield, and carbon:nitrogen ratio were determined following standard methods. In the adsorption experiment, adsorbent dosage, agitation speed, contact time, pH, and initial concentration were optimized. Models were used to examine the adsorption isotherms and kinetics. The ability of activated coffee husk carbon to desorb Cr was investigated. The adsorbent functional groups and surface morphology were examined using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscope (SEM), respectively. Analysis of the physicochemical characteristics of the adsorbent showed that the activated coffee husk carbon has good quality, and thus, playing an important role in metal adsorption. Furthermore, FTIR analysis also confirmed the presence of hydroxyl, carboxyl, and other important functional groups, which promote heavy metal adsorption. The adsorption process optimization revealed 99.65% maximum Cr adsorption efficiency at 120 min contact time, 40 mgL-1 initial concentration, 150 rpm agitation speed, pH 7.0, and 20 gL-1 adsorbent dosages. From the adsorption model studies, Freundlich sorption isotherm and pseudosecond-order models were well fitted with respective [Formula: see text] values of 0.987 and 0.999. A 60% Cr was removed according to desorption studies. In general, due to the ease with which coffee husk can be obtained from coffee processing facilities, its use as an absorbent will be cost-effective and considered as an alternative option in removing Cr metal from wastewaters.

Application of aerobic granulation in SBR technology to treat low-strength urban wastewater

Sequencing Batch Reactor - SBR is an advanced technology to treat wastewater in Vietnam and around the world. Many studies showed that aerobic granular sludge could adapt to various types of wastewater with different organic loads such as industrial wastewater, winery and brewery wastewaters, landfill wastewater, municipal wastewaters. This paper presents the removal results of COD, NH4+-N, T-N, T-P by applying aerobic granulation in SBR technology to treat low-strength urban wastewater at Hanoi in the laboratory. Research wastewater is taken from Kim Lien wastewater treatment plant with OLR 0.4-0.6 kg COD/m3.day, equivalent to COD 150-200 mg/l, and studied for 55 days. Research is processed using the SBR technology with a bubble column of 0.11 m in diameter, 1 m in height, a water storage height of 0.8 m, and a working volume of 2.5 l. The reactor was sequentially operated 6 cycles/day. A cycle time is 4 h, in which: water filling phase 1-2 min, aeration phase 180 min, resting phase 20-30 min, discharge phase 10-15 min. The results showed the stable operation of the SBR technology with COD removal efficiency over 92% COD, 90% NH4+-N, 20% T-N, and 50% T-P.

Applicability of biological wastewater treatment for various industries

Biological treatment methods are used to remove organic and some inorganic substances from wastewater using the simplest organisms that use these substances for nutrition, breaking them down using cellular processes. The article deals with the aerobic, anaerobic and anoxic stages of biological wastewater treatment. Their differences are explained and the best way to use biological processes is analyzed according to the type of industry/production. At wastewater treatment plants, anaerobic treatment is often used at first to remove a significant part of organic substances from wastewater before sending them for further aerobic treatment. Aerobic treatment is effective for various types of wastewater, especially with lower biochemical oxygen demand (BOD) and chemical oxygen demand (COD). A comparative analysis of wastewater composition from food, oil and gas processing, pharmaceutical and pulp and paper industries was carried out. In the presence of organic compounds, the technology is chosen depending on the total organic matter content or the total COD content, which characterizes the total organic matter in water. A combination of anaerobic and aerobic methods is possible, if a discharge into the sewer system or into water bodies is required. The grounds for the application of biological wastewater treatment of these industries are given.

Development of polyethyleneimine-starch fibers stable over the broad pH range for selective adsorption of gold from actual leachate solutions of waste electrical and electronic equipment

Polyethyleneimine (PEI)-starch fibers were fabricated as adsorbents for the selective recovery of gold from waste electrical and electronic equipment (WEEE). They were prepared by a simple method of spinning a mixture of PEI and starch in a glutaraldehyde solution, which is a crosslinking agent. The PEI-starch fibers were stable over the broad pH range, thereby suggesting that they are highly applicable for various types of wastewater. The characterization and adsorption mechanism of the PEI-starch fibers were investigated by BET, FT-IR, XRD, and XPS analyses. According to the Langmuir model, the maximum Au(III) uptake by the PEI-starch fibers was estimated to be 1055.59 ± 63.78 mg/g at pH 1.0. The adsorbed Au(III) was sequentially reduced to Au(I) and then Au(0) owing to electron transfer when N–C and C–OH present in the PEI-starch fibers were oxidized to NC and CO, respectively. Moreover, PEI-starch fibers were stable in WEEE-leached aqua regia (diluted to pH 1.0) and bioleaching solution (pH 9.3) and showed excellent selectivity for gold.

Salt-Resistant, Self-Floatable Fe2O4/Ppy Nanoparticles Decorated Wood Pulp Sponge for Solar-Driven Seawater Desalination

Water scarcity has become a major global challenge in recent years needed to deal with urgently. Solar evaporation has emerged as a renewable energy source and a novel technique for clean water production and wastewater treatment. However, developing a high-performance, environment-friendly, and scalable solar evaporator remains a significant challenge. Herein, we developed a high-performance, self-floatable, environmentally friendly, and single-step manufacturing of a two-dimensional solar steam generator. The developed solar evaporator is composed of facile coating of Fe2O4@PPy nanoparticles (NPs) deposit on low-cost and commercially available super hydrophilic wood pulp sponge which offers a sustainable solution to the ever-growing issues of the energy and water crises. The as-prepared foam exhibits good wettability (zero contact angle), salt-resistance (3 g /180 minutes), low thermal conductivity (0.225 W m−1 K−1), and excellent light absorption of ∼95% due to the omnidirectional porous surface of Fe2O4@PPy NPs. The broadband solar absorption of Fe2O4@PPy solar evaporator is capable to transform into thermal energy (42.3 ˚C) and generate vapors (1.62 kg m-2 h-1) along with 93 % photothermal conversion efficiency under one sun (1 kW m-2). Furthermore, the presented prototype can be directly installed to purify various types of wastewaters with a high rejection ratio of heavy metal ions (nearly 100%). This simple fabrication process with renewable polymer resources and photothermal materials provides fundamental guidance and practical application value toward developing high-performance solar evaporation technologies for remote areas and individuals. Keywords: Fe2O4@PPy, solar steam generation, wood pulp, polypyrrole.

Effects of wastewater type on stability and operating conditions control strategy in relation to the formation of aerobic granular sludge - a review.

Currently, research trends on aerobic granular sludge (AGS) have integrated the operating conditions of extracellular polymeric substances (EPS) towards the stability of AGS systems in various types of wastewater with different physical and biochemical characteristics. More attention is given to the stability of the AGS system for real site applications. Although recent studies have reported comprehensively the mechanism of AGS formation and stability in relation to other intermolecular interactions such as microbial distribution, shock loading and toxicity, standard operating condition control strategies for different types of wastewater have not yet been discussed. Thus, the dimensional multi-layer structural model of AGS is discussed comprehensively in the first part of this review paper, focusing on diameter size, thickness variability of each layer and diffusion factor. This can assist in facilitating the interrelation between disposition and stability of AGS structure to correspond to the changes in wastewater types, which is the main objective and novelty of this review.

Constructed wetlands as a sustainable technology for wastewater treatment with emphasis on chromium-rich tannery wastewater

Water scarcity is a major threat to agriculture and humans due to over abstraction of groundwater, rapid urbanization and improper use in industrial processes. Industrial consumption of water is lower than the abstraction rate, which ultimately produces large amounts of wastewater such as from tannery industry containing high concentration of chromium (Cr). Chromium-contaminated tannery industry wastewater is used for irrigation of food crops, resulting in food safety and public health issues globally. In contrast to conventional treatment technologies, constructed wetlands (CWs) are considered as an eco-friendly technique to treat various types of wastewaters, although their application and potential have not been discussed and elaborated for Cr treatment of tannery wastewater. This review briefly describes Cr occurrence, distribution and speciation in aquatic ecosystems. The significance of wetland plant species, microorganisms, various bedding media and adsorbents have been discussed with a particular emphasis on the removal and detoxification of Cr in CWs. Also, the efficiency of various types of CWs is elaborated for advancing our understanding on Cr removal efficiency and Cr partitioning in various compartments of the CWs. The review covers important aspects to use CWs for treatment of Cr-rich tannery wastewater that are key to meet UN’s Sustainable Development Goals.