Various Types Of Wastewater Research Articles

Real Options Analysis of Constructed Wetlands as Nature-Based Solutions to Wastewater Treatment Under Multiple Uncertainties: A Case Study in the Philippines

Constructed wetlands (CWs) are man-made ecosystems that mimic the properties of natural wetlands. They are being utilized to treat various types of wastewater, from domestic to agricultural, municipal, commercial, and industrial effluents. Despite their economic viability and environmental benefits, their widespread adoption is challenged with several uncertainties, including public support, technology learning, and the impacts of climate change. This study proposes a valuation framework that considers these uncertainties to analyze the feasibility of CWs. Using existing CWs in the Philippines as a case, this study employs the real options approach to (1) evaluate the feasibility of CW projects using cost–benefit analysis, (2) calculate the value of postponing decisions to implement CWs projects using real options analysis, and (3) identify the optimal investment decisions for CWs considering the opportunity costs of waiting and uncertainties in public support and the impacts of climate change. Results found that the project is feasible with a net present value of USD 88,968. Yet, the real options value at USD 208,865 indicates that postponing the project may be a more optimal decision. Considering the cost of waiting, the valuation identified the threshold at 5.56% to immediately implement the project. The calculated values increase with uncertainty in public support but decrease with uncertainty in climate change’s impacts. Yet, these uncertainties prolong the decision to implement CW projects until they are resolved. The findings from this case study provide a basis for recommendations to support the adoption of CWs as nature-based water treatment for a more sustainable future.

Multicolor fluorescence strategy for rapid and simultaneous detection of antibiotics in wastewaters and the entire process detection mechanisms

Fluorescence nano-sensors have recently emerged as a cost-effective, convenient, and time-saving tool for high-throughput detection of antibiotics in wastewater. However, their application is primarily limited to tetracycline and penicillin due to a lack of understanding of key influencing factors. Herein, we propose a convenient strategy to expand their application range by increasing the colors of fluorescence nano-sensors. The newly three-colored nano-sensors were prepared to detect erythromycin and metronidazole, which has rarely been reported before. For in-situ detection, a smartphone app-based detection method was developed, and the detection method was optimized to obtain the widest detection limit. The fluorescence nano-sensors demonstrated satisfactory recovery rates with promising accuracy in various types of wastewaters. Moreover, a mechanism investigation comprising experimental analysis and theoretical simulation was developed to elucidate their detection mechanisms and provide ideas for improving their performance. Consequently, several improvements were proposed further to enhance the analysis selectivity, sensitivity, and accuracy. This work presents a new perspective on broadening the application of fluorescence nano-sensors and provides a novel route to analyze the detection mechanism, enabling rapid, high-throughput and in-situ detection of antibiotics.

Advancement in constructed wetland microbial fuel cell process for wastewater treatment and electricity generation: a review.

The constructed wetland coupled with a microbial fuel cell (CW-MFC) is a wastewater treatment process that combines contaminant removal with electricity production, making it an environmentally friendly option. This hybrid system primarily relies on anaerobic bioprocesses for wastewater treatment, although other processes such as aerobic bioprocesses, plant uptake, and chemical oxidation also contribute to the removal of organic matter and nutrients. CW-MFCs have been successfully used to treat various types of wastewater, including urban, pharmaceutical, paper and pulp industry, metal-contaminated, and swine wastewater. In CW-MFC, macrophytes such as rice plants, Spartina angalica, Canna indica, and Phragmites australis are used. The treatment process can achieve a chemical oxygen demand removal rate of between 80 and 100%. Initially, research focused on enhancing power generation from CW-MFC, but recent studies have shifted towards resource recovery from wastewater. This review paper provides an overview of the development of constructed wetland microbial fuel cell technology, from its early stages to its current applications. The paper also highlights research gaps and potential directions for future research.

Simultaneous efficient evaporation and stable electricity generation enabled by a wooden evaporator based on composite photothermal effect

The current solar interfacial evaporators have limited evaporation performance due to their single photothermal mechanism, insufficient light utilization, and improper heat management. Therefore, a novel approach involving polypyrrole (PPy) and Ag nanoparticles (AgNPs) modified wooden evaporator (AgPW) using an in-situ polymerization and growth method was proposed for efficient and sustainable freshwater purification. The composite photothermal effect of PPy and AgNPs led to a significantly enhanced light absorption capacity and superior photothermal conversion efficiency in a wide spectrum range, which coupled with the rapid water transport capacity conferred by the regular vertical channels and superior hydrophilicity of the delignified wood, resulted in remarkable evaporation performance through the coordinated regulation of thermal and water management. The optimized AgPW50 achieved an evaporation rate of up to 2.04 kg m−2 h−1 and an evaporation efficiency of 90.7 % under 1 kW m−2 irradiation. Importantly, this evaporator was highly salt resistant and long-term desalination stability, and can also be extended to the purification of various types of wastewaters while converting the released waste heat into stable electricity generation. The innovative Ag/PPy wooden evaporator integrates biomass resources with solar energy utilization, demonstrating an environmentally friendly, efficient and cost-effective strategy for seawater desalination and energy production, providing a new sustainable development pathway to solve the challenge of balancing water security and energy consumption.

Applications of the Microalgae Chlamydomonas and Its Bacterial Consortia in Detoxification and Bioproduction.

The wide metabolic diversity of microalgae, their fast growth rates, and low-cost production make these organisms highly promising resources for a variety of biotechnological applications, addressing critical needs in industry, agriculture, and medicine. The use of microalgae in consortia with bacteria is proving valuable in several areas of biotechnology, including the treatment of various types of wastewater, the production of biofertilizers, and the extraction of various products from their biomass. The monoculture of the microalga Chlamydomonas has been a prominent research model for many years and has been extensively used in the study of photosynthesis, sulphur and phosphorus metabolism, nitrogen metabolism, respiration, and flagellar synthesis, among others. Recent research has increasingly recognised the potential of Chlamydomonas-bacteria consortia as a biotechnological tool for various applications. The detoxification of wastewater using Chlamydomonas and its bacterial consortia offers significant potential for sustainable reduction of contaminants, while facilitating resource recovery and the valorisation of microalgal biomass. The use of Chlamydomonas and its bacterial consortia as biofertilizers can offer several benefits, such as increasing crop yields, protecting crops, maintaining soil fertility and stability, contributing to CO2 mitigation, and contributing to sustainable agricultural practises. Chlamydomonas-bacterial consortia play an important role in the production of high-value products, particularly in the production of biofuels and the enhancement of H2 production. This review aims to provide a comprehensive understanding of the potential of Chlamydomonas monoculture and its bacterial consortia to identify current applications and to propose new research and development directions to maximise their potential.

Oxygen deficient BaTiO3 loading sub-nm PtOx for photocatalytic biological wastewater splitting to green hydrogen production

Efficient photocatalytic production of H2 from wastewater rather than pure water is a dual solution to address environmental and energy crises. However, the rapid recombination of photo induced charges in photocatalysts and the inevitable electron consumption caused by organic pollutants pose significant challenges to bifunctional photocatalysis. In this study, we designed an amorphous PtOx supported BaTiO3 single catalyst (named BTPOv-0.09) characterized by oxygen vacancies. This catalyst provides Pt-O-Ti3+ charge separation sites and can effectively generate H2 (1891 μmol · g−1 · h−1), while oxidizing pefloxacin (rate constant k = 0.0485 min−1). It is worth noting that the catalytic performance of BTPOv-0.09 significantly exceeds that of the original BaTiO3, exhibiting 49 and 39 times higher H2 production activity and rate constants (BaTiO3, k = 0.00119 min−1). BTPOv-0.09 exhibits significant H2 production activity in various types of wastewater, highlighting its versatility and promising role in wastewater treatment and renewable energy production.

Ultra-stable, lightweight and superelastic waste flax-based aerogel for multifunctional applications

Multifunctional aerogels constructed from natural waste biomass have attracted great attention in the fields of green energy harvesting, flexible wearable sensing and natural environment restoration. However, the complex and polluted extraction of natural materials and the poor mechanical property have seriously hindered the development of natural material-based aerogels. Hence, a novel aerogel with capabilities of high-elasticity, stabilized constructions and weightlessness was prepared via waste flax staple fibers (simply physically disrupting) and multi-walled carbon tubes. Due to the assistance of cross-linking agent and carbon tubes, the aerogel was endowed with multiple properties including high photothermal conversion (97.2 %), superstability at the wide range of 0–29 KPa and outstanding compression resilience at different strains (up to 60 % and 100 cycles). Consequently, it is promising that the fabricated aerogel may be as a piezoresistive sensor to monitor different locations of the body for continuous detection of motor behavior. Further, the sample was also utilized as an evaporator with excellent water evaporation effect (1.93 kg·m−2·h−1) under 1 sun and to efficiently purify various types of wastewater for obtaining pure water. This multi-purpose aerogels prepared in this work display admirable potential for efficient environmental purification, advanced smart materials and green energy harvesting.

A validation workflow for treatment wetland performance data

ABSTRACT Treatment wetlands (TWs) effectively remove target pollutants and enhance urban water circularity and resilience. They constitute a prominent solution for urban wastewater treatment, thanks to their adaptability across various types of wastewater, scales and climatic conditions. However, the disparity in TW designs and the focus on a restricted set of variables applicable to research studies impede any comprehensive evaluation and comparison of TW performance. Our study introduces a methodology for data validation, in concurrently establishing a workflow specific to TW. This approach is aimed at defining the scope and relationships within the data, implementing checks and concatenating them into a quality flag, as an initial step towards building reliable statistical models. We underscore the importance of both mobilising comprehensive knowledge and identifying customary, yet implicit, choices intertwined in data processing. As for the application workflow, we collected and analysed data sourced from peer-reviewed papers on horizontal and vertical flow TW. Deficiencies were noted in key data elements like dimensions, concentrations and operational conditions. For the data analysis, relationships are highlighted between variables introduced for modelling purposes. These methodologies and workflows assess the quality of the data, in paving the way towards more dependable statistical models for TW design and implementation.

A Comprehensive Review on the Use of Wastewater in the Manufacturing of Concrete: Fostering Sustainability through Recycling

The primary aim of this review article is to find the influence of wastewater and its characteristics on recycling as an alternative to potable water for concrete preparation. On the other hand, scarcity, and the demand for freshwater for drinking are also increasing day by day around the globe. About a billion tons of freshwater is consumed daily for concrete preparation for various operations such as mixing and curing, to name a few. The rapid development of certain industries such as textile, casting, stone cutting, and concrete production has caused the water supply to be severely affected. Recycling wastewater in concrete offers various potential benefits like resource conservation, environmental protection, cost savings, and enhanced sustainability. This article reviews the effect of various types of wastewater on various physical and chemical properties of wastewater, rheological characteristics, strength, durability, and microstructure properties of concrete. It also explores the potential effects of decomposing agents on enhancing concrete properties. Currently, limited research is available on the use of various types of wastewater in concrete. Hence, there is a need to develop various methods and procedures to ensure that the utilization of wastewater and treated wastewater is carried out in the production of concrete in a sustainable manner. Although wastewater can reduce the workability of fresh concrete, it can also increase its strength and long-term performance of concrete. The use of various types of wastewater, such as reclaimed water and tertiary-treated wastewater, was found to be superior compared to those using industrial- or secondary-treated wastewater. Researchers around the globe agree that wastewater can cause various detrimental effects on the mechanical and physical properties of concrete, but the reductions were not significant. To overcome limited scientific contributions, this article reviews all the available methods of using various types of wastewater to make concrete economically and environmentally friendly. This research also addresses possible challenges with respect to the demand for freshwater and the water crisis.

Sorting Out the Latest Advances in Separators and Pilot-Scale Microbial Electrochemical Systems for Wastewater Treatment: Concomitant Development, Practical Application, and Future Perspective.

To date, dozens of pilot-scale microbial fuel cell (MFC) devices have been successfully developed worldwide for treating various types of wastewater. The availability and configurations of separators are determining factors for the economic feasibility, efficiency, sustainability, and operability of these devices. Thus, the concomitant advances between the separators and pilot-scale MFC configurations deserve further clarification. The analysis of separator configurations has shown that their evolution proceeds as follows: from ion-selective to ion-non-selective, from nonpermeable to permeable, and from abiotic to biotic. Meanwhile, their cost is decreasing and their availability is increasing. Notably, the novel MFCs configured with biotic separators are superior to those configured with abiotic separators in terms of wastewater treatment efficiency and capital cost. Herein, a highly comprehensive review of pilot-scale MFCs (>100 L) has been conducted, and we conclude that the intensive stack of the liquid cathode configuration is more advantageous when wastewater treatment is the highest priority. The use of permeable biotic separators ensures hydrodynamic continuity within the MFCs and simplifies reactor configuration and operation. In addition, a systemic comparison is conducted between pilot-scale MFC devices and conventional decentralized wastewater treatment processes. MFCs showed comparable cost, higher efficiency, long-term stability, and significant superiority in carbon emission reduction. The development of separators has greatly contributed to the availability and usability of MFCs, which will play an important role in various wastewater treatment scenarios in the future.

Floating Aquatic Macrophytes in Wastewater Treatment: Toward a Circular Economy

Floating aquatic macrophytes have a high level of proficiency in the removal of various contaminants, particularly nutrients, from wastewater. Due to their rapid growth rates, it is imperative to ensure the safe removal of the final biomass from the system. The ultimate macrophyte biomass is composed of lignocellulose and has enhanced nutritional and energy properties. Consequently, it can serve as a viable source material for applications such as the production of bioenergy, fertilizer and animal feed. However, its use remains limited, and in-depth studies are scarce. Here, we provide a comprehensive analysis of floating aquatic macrophytes and their efficacy in the elimination of heavy metals, nutrients and organic pollutants from various types of wastewater. This study offers a wide-ranging scrutiny of the potential use of plant biomasses as feedstock for bioenergy generation, focusing on both biochemical and thermochemical conversion processes. In addition, we provide information regarding the conversion of biomass into animal feed, focusing on ruminants, fish and poultry, the manufacture of fertilizers and the use of treated water. Overall, we offer a clear idea of the technoeconomic benefits of using macrophytes for the treatment of wastewater and the challenges that need to be rectified to make this cradle-to-cradle concept more efficient.

The Potential of Commercial Biomass-Based Activated Carbon to Remove Heavy Metals in Wastewater – A Review

Commercial activated carbon is a type of adsorbent commonly used in adsorption processes. However, the use of commercial carbon in wastewater treatment is still limited, due to the scarce availability of precursors and their high cost. Biomass as an activated carbon precursor has been reported to have high efficiency in removing various heavy metals in wastewater. This study aims to review the potential of biomass-based activated carbon to adsorb heavy metals in terms of biomass constituent components, heavy metal removal, and future prospects. The method in this study is a systematic literature review, or SLR, to collect data from online databases such as Google Scholar, PubMed, and ScienceDirect. The results show that biomass-based activated carbon is effective in the removal of heavy metals in various types of wastewater. The removal effectiveness for different types of biomass ranged from 84–99% for Pb2+ ions, 55–92% for Cd2+ ions, 84–99% for Pb2+ ions, 96% for As2+ ions, 80–100% for Cr2+ ions, 25–97% for Fe2+ ions, 50–99% for Ni2+ ions, and 62–98% for Cu2+ ions, and 98% for Ti ions. These results show that heavy metals have different affinities to activated carbon from biomass, from all heavy metals, Fe2+ and Cd2+ ions have the lowest affinity, so the activated carbon used to remove Fe2+ and Cd2+ metals needs to be produced with higher porosity and surface area. The removal of heavy metals using activated carbon from biomass is limited by adsorbent dosage, contact time, solution pH, temperature, initial adsorbate concentration, particle size, and stirring speed. In future research, it is expected that activated carbon from biomass has a high adsorption capacity, is economical cost, is environmentally friendly and can be used on a larger scale.

A multi-stage enhanced flocculation reactor for the treatment of simulated shale gas hydraulic fracturing flowback fluid: Effect of aspect ratios for the intense mixing section

Flocculation is a significant process in treating shale gas hydraulic fracturing flowback fluids. To achieve a high removal rate of pollutant, a range of multi-stage enhanced flocculation reactors that incorporated sequential intense, moderate, and weak mixing sections along the flow direction were devised, in which the aspect ratios (ARs) in the intense mixing section were varied. The results of the computer simulation indicated that the reactor with AR of 3.5 exhibited a gradual decrease in velocity and energy along the flow direction, and the flow field distribution is highly uniform and symmetrical. The generated flow field promoted the formation of small flocs in the intense mixing section and facilitated the collision of small flocs in the moderate mixing section, while preventing the fragmentation of flocs in the weak mixing section, therefore resulting in the generation of large and compact flocs. Moreover, the generated flocs demonstrated a good resistance to shear and oscillation, facilitating their separation from the simulated flowback fluids. The obtained reactor achieved remarkable removal efficiencies of 80.15 % for COD and 89.06 % for turbidity. Furthermore, when treating bentonite suspension, the multi-stage flocculation reactor achieved a turbidity removal rate of 99.34 % with a processing time of only 2.38 min and a settling time of just 20 min. This demonstrated the broad applicability of this reactor to various types of wastewater. This work provides valuable insights into the design of efficient flocculation reactors by integrating multiple mixing intensities within a reactor.

Floating Constructed Wetlands Efficiency in Removal of Total Hardness, Calcium and Magnesium from Secondary Treated Sewage Water

Floating Constructed wetlands (FCWs) also popular as Floating Treatment Wetlands (FTWs) were used in situ for suspended solids,heavy metals, biological oxygen demand (BOD), chemical oxygen demand (COD), faecal coliform bacteria, nutrients and heavy metalsremediation from various types of wastewater. However, there was limited data available on total hardness (TH), calcium (Ca2+) andmagnesium (Mg2+) ions removal from secondary treated sewage water (STSW). This article focuses on TH, Ca2+ and Mg2+ ions removalefficiency of FCWs from STSW. Mesocosms include a control (without FCWs), FCWs planted with macrophyte plant species Cannaindica var. indica L. (S1) and Typha angustifolia L. (S2) and one mixed culture with both Typha and Canna plants (S3). The changes in TH,Ca2+ and Mg2+ concentration in wastewater were recorded at a 7-day hydraulic retention time (HRT) for 7 batches. Mean percentageremoval efficiency recorded was 9.8, 1.7, 4.9 and 11.2% for TH, -3.4, 7.6, 27.1 and 14.1% for Ca2+and 29.5, 4.2, -0.6, and -0.6% for Mg2+,in Control, S1, S2, S3 FCWs respectively. Results showed that S2 and S3 FCWs are effective in TH and Ca2+ removal but not for Mg2+ ions.Thus, FCWs can reduce TH and Ca2+ ions concentration along with nutrients from STSW.

An efficient interfacial solar evaporator featuring a hierarchical porous structure entirely derived from waste cotton

Interfacial solar evaporators are widely used to purify water. However, photothermal materials commonly constituting most interfacial solar evaporators remain expensive; additionally, the inherent structure of the evaporators limits their performance. Furthermore, the large amount of waste cotton produced by the textile industry is an environmental threat. To address these issues, we propose an interfacial solar evaporator, H-CA-CS, with a hierarchical porous structure. This evaporator is made entirely of waste cotton and uses carbon microspheres (CMS) and cellulose aerogel (CA) as photothermal and substrate materials, respectively. Additionally, its photothermal layer (CS layer) has large pores and a high porosity, which promote light absorption and timely vapor escape. In contrast, the water transport layer (CA layer) has small pores, providing a robust capillary effect for water transport. Combined with the outstanding light absorption properties of CMS, H-CA-CS exhibited superior overall performance. We found that H-CA-CS has an excellent evaporation rate (1.68 kg m−2 h−1) and an efficiency of 90.6 % under one solar illumination (1 kW m−2), which are superior to those of many waste-based solar evaporators. Moreover, H-CA-CS maintained a mean evaporation rate of 1.61 kg m−2 h−1, ensuring sustainable evaporation performance under long-term scenarios. Additionally, H-CA-CS can be used to purify seawater and various types of wastewater with removal efficiencies exceeding 99 %. In conclusion, this study proposes a method for efficiently using waste cotton to purify water and provides novel ideas for the high-value use of other waste fibers to further mitigate ongoing environmental degradation.

A critical review on phytoremediation of environmental contaminants in aquatic ecosystem

The rapid urbanization and economic development have resulted in an unprecedented pollution of the entire biosphere. Aquatic ecosystems have become a sink for the discharge of numerous pollutants ranging from nutrients, heavy metals, volatile organic compounds, hydrocarbons, pesticides, medicines, pathogens, and explosives. The accumulation of these pollutants poses a serious threat to aquatic biodiversity, and drinking contaminated water poses severe health hazards in humans. Phytoremediation, an eco-accommodating process, aids in the maintenance of aquatic ecosystem functionality by detoxifying, decomposing, converting, or chelating contaminants, allowing for the proper treatment of wastewater-contaminated water bodies. The development of phytoremediation technology was facilitated by the economic aspects and side effects of conventional treatment technologies. Nevertheless, constructed wetlands have acquired popularity among the numerous accessible methods for treating and recycling diverse wastewaters because they fulfill the criteria of sustainability, public health maintenance, esthetic balance, design intricacy, and cost. The prolonged-release of untreated industrial waste, domestic sewage, accidental spills, rainfall run-off, and direct solid waste disposal all have a substantial influence on aquatic environments. Both live and dead macrophyte biomass may be utilized in phytoremediation; however, dead biomass is typically favored for treating industrial effluents due to lower cost, ease of disposal, and lack of active biochemical machinery that causes metal toxicity and plant death. Some of the barriers to translating phytoremediation technology from the lab to the field include the issue of disposing of biomass and the seasonal growth of aquatic macrophytes. Yet, via numerous works, an eco-sustainable model has been created that could mitigate some of the restrictions. Macrophyte waste biomass has a wide range of productive uses. Future potential for the utilization of macrophytes in phytoremediation investigations includes genetic engineering, biodiversity exploration, and X-ray diffraction spectroscopy. This emerging technology may advance environmental science and technology using a multidisciplinary and integrated approach. This review, thus focuses on the various contaminants found in aquatic ecosystems, their treatment by various phytoremediation processes, some successful phytoremediation studies conducted so far for remediation purposes, and myriad types of constructed wetlands utilized for attenuating pollution levels in various types of wastewaters to bring them down to permissible levels.

Synthesis of Graphene Nanoplatelet-Alginate Composite Beads and Removal of Methylene Blue from Aqueous Solutions

The discharge of various types of wastewater into natural streams leads to significant problems by increasing the toxicity of the wastewater. For this reason, methods and materials are being developed by researchers in line with effective, economic, and environmental principles. In this study, the removal of methylene blue, a toxic dyestuff, from aqueous solutions was investigated by synthesizing sodium alginate (SA) and graphene nanoplatelet-sodium alginate composite (SA-GNP) beads. The structural characteristics of the materials were analyzed using FTIR, TGA, optical microscope, and SEM methods. All parameters determining the efficiency of the methylene blue adsorption system were optimized in a batch system. The effects of various factors, such as adsorbent amount, contact time, adsorption temperature, dye concentration, solution pH, pHzpc values of SA and SA-GNP beads, presence of different ions, and beads swelling, on the adsorption process, were investigated. To investigate the mechanism of the adsorption system, the adsorption data were fitted to a non-linear form of the Langmuir, Freundlich, and Temkin equilibrium isotherm models, as well as the Pseudo-first-order (PFO), Pseudo-second-order (PSO), and Bangham kinetic models. High regression coefficients were achieved in the studied kinetic and isotherm models (0.86 ≤ R2 ≤ 0.99), and the experimental data were found to be compatible with the model parameters. Maximum adsorption capacities (qm) of 167.52 mg/g and 290.36 mg/g were obtained for the SA and SA-GNP adsorbents, respectively, at 308 K. The optimum temperature for both adsorption systems was found to be 308 K. The efficiency of methylene blue dyestuff removal was improved with graphene nanoplatelet-based adsorbents.

Treatment of Wastewater from Soil Washing with Soluble Humic Substances Using Biochars and Activated Carbon

Energy can be obtained by pyrolysis of organic wastes, and the solid residue of pyrolysis (biochar) can be used as an adsorbent for the treatment of various types of wastewater. Although soil washing can effectively remediate metal-contaminated soils, it can generate significant amounts of soil washing wastewater (SWW). This study investigated the effectiveness of using activated carbon and various biochars to treat SWW from the remediation of soil heavily contaminated with cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) with soluble humic substances (SHS) from municipal sewage sludge. Willow biochar (BW), plant biomass biochar (BPB), coconut shell biochar (BCH), and Norit SX2 activated carbon (ACN) were tested at different dosages (12.5–100 g/L) and adsorption times (30–1440 min) for the treatment of SWW. At 100 g/L dosage, biochar removed Cd, Cu, Ni, Pb, and Zn with 56–83%, 32–41%, 18–42%, 75–83%, and 44–83% efficiency, respectively, while ACN removed them with 87–95% efficiency. Only BW and ACN removed soluble organics with efficiencies of 49% and 94%, respectively, at the highest dosage. Adsorption of metals and soluble organics was mainly controlled by physisorption and chemisorption. Diffusion of metals and soluble organics into the different pore sizes was not the most important rate-limiting step. ACN and BW had better structural properties and treated SWW most effectively. BPB and BCH removed metals but not soluble organics, which could be beneficial for SHS recycling.

GLOBAL TRENDS AND RESEARCH HOTSPOTS OF AEROBIC GRANULAR SLUDGE FOR WASTEWATER TREATMENT USING SCOPUS DATABASE: A BIBLIOMETRIC ANALYSIS

The aerobic granular sludge (AGS) system is a promising technology that is suitable for the treatment of various types of wastewaters. This system has received great attention from many researchers due to its wide range of applications and potential as a cost effective system. However, only a few reports are available in analyzing the progress of AGS research in wastewater treatment over the last 20 years. Therefore, in the present work, a bibliometric analysis was carried out to trace the global research trends and current hotspots of AGS in wastewater treatment from 1997 to 2020, based on the Scopus database. The bibliometric data was visualized using the VOSviewer software. A total of 1,347 articles were published in 160 journals across 19 subject categories, involving 50 countries and 129 academic institutions. Results showed that Bioresource Technology (175, 12%), Water Research (94, 6.96%), and Huanjin Kexue Environmental Science (78, 5.77%) dominated in the top 3 journals. Environmental Science (1036, 38%), China (716, 53%), and Harbin Institute of Technology (98, 7.28%) were the most productive subject category, country, and academic institution, respectively. The AGS research hot topics and future research directions were discovered through the analysis of the most frequently used keywords obtained in bibliometric maps.

Photoactive Materials for the Catalytic Decomposition of Water Pollutants

The use of UV and Vis light (in the form of solar energy) in the presence of semiconductor nanostructured materials as photocatalysts is effective for the adequate removal of a wide spectrum of pollutants (resistant to other degradation techniques) in various types of wastewater, which are important elements of the development of science related to photocatalysis [...]