Wastewater Sources Research Articles

Driving Sustainability: Reusing Microalgae Wastewater to Grow Pelargonium x hortorum

ABSTRACT The scarcity of freshwater in many countries, the excessive production of wastewater, and the high demand for water for agriculture have been responsible for the implementation of wastewater for agricultural irrigation, thus achieving environmental benefits. The purpose of this research is to take advantage of wastewater generated in the production of microalgae and to analyze its impact on the growth and development of Pelargonium x hortorum, thus seeking to promote the reuse of resources and explore sustainable alternatives in agriculture. Two sources of wastewater were used for microalgae production (wastewater from the University of Almeria and slurry from a pig farm). The treatments used were: Control = (Tap water irrigation), Input-WW = (Irrigation with black water, inlet of the reactor) this wastewater was collected from Almeria University used at the beginning of microalgae production in the bioreactors, Outlet-WW = (Irrigation with black water, outlet of the reactor) – this is the wastewater collected after being treated with microalgae in the bioreactors, Input-WP = (Irrigation with slurry, inlet of the reactor) – this is the slurry that was used at the beginning of microalgae production in the bioreactors, Outlet-WP = (Irrigation with slurry, outlet of the reactor) are the purified slurry waters once they have been used for the production of microalgae in the bioreactors. The use of Outlet-WW has an adverse impact on plant diameter and number of flowers compared to the Control, which affected flower dry weight. The other biometric measurement parameters were not influenced. The WP wastewater showed elevated concentrations of nitrogen and potassium (N, K). On the other hand, the WW wastewater showed an elevated concentration of nitrogen, but also a high electrical conductivity (EC). This study concluded that the Outlet-WP treatment had no significant differences in dry weights compared to the Control treatment, but there was a significant reduction in the height and diameter of the plants as well as in the color of the leaves. This wastewater can be a source of nutrients for crop growth as well as a water source, but further research studies are necessary to determine the best way to apply it.

DAIRY PLANT RAW SEWAGE LONGITUDINAL INFLUENCE ON RIVERINE WATER QUALITY, BOTTOM INVERTEBRATES AND THE MASS DEVELOPMENT OF HEALTH-THREATENING MICROORGANISMS IN AGRICULTURAL RIVER REACH, NE BULGARIA

Dairy plants (DPs) are the most significant polluting source of wastewater in Europe causing overall degradation of freshwater ecosystems dictated by the quality characteristics of the effluent which is more polluting than municipal sewage waters. This leads to environmental problems related to various biological quality elements such as macroinvertebrates and health hazards by facilitating the increase of coliforms. The paper aims to assess the longitudinal macroinvertebrate and water quality alteration in a downstream direction from a DP and to point out the most abundant genus of microorganisms identifying potentially hazardous species in agricultural areas from which nutrients are leaching. To achieve this a river reach with 3.3 km length was investigated for 3 years. Four sampling sites were established for invertebrate and water samplings. The sites were monitored in the spring-summer and autumn periods. The microbiological survey was conducted once from the most polluted sites and remote sensing data was used to evaluate the seasonal dynamics of nutrient leaching upstream from the dairy plant. Multiple factor analysis (MFA) was used to determine the most important environmental parameters for the biological indices and the most influenced one from normalized difference in vegetation cover and moisture content, in the surrounding arable lands. Our results demonstrated that ammonia was the only parameter longitudinally decreasing downstream from the DP and was the nutrient with the strongest influence on bottom invertebrates along with phosphates. Conductivity, phosphates, nitrites, and sulfates were longitudinally increasing partly because of microbiological and macroinvertebrate activity. Health-threatening microorganisms were found in great quantities for 1.5 km downstream of the DP and macroinvertebrates did not recover for the 3.3 km long river stretch. The approach of this study could be beneficial for the planning of monitoring а heavily polluted water bodies from DPs in terms of defining the right distance for quality assessment.

Degradation of azo dye (direct red 89) using H2O2/periodate process-parameter optimization and mixture composition evaluation.

As a fast and efficient process, a periodate (PI)-based advanced oxidation process was used to degrade direct red 89 (DR89), wherein hydrogen peroxide (H2O2) was employed to activate PI (H2O2/PI process) to investigate the effect of operating parameters and mixture composition. The PI was efficiently activated by H2O2 to degrade 67% of DR89 within 1min. Acidic pH was more favorable to high-efficiency degradation than the basic pH; at pH 3 degradation rate was 94.31%, while it was only 20.92% at pH 11. The degradation rates were further enhanced with increasing H2O2 and PI dose up to certain optimum values, later it decreased which was dependent upon the amount of hydroxyl (●OH) and iodyl (IO3●) radicals produced. The quenching experiments suggested that IO3●, ●OH, 1O2, and O2●- are the predominant reactive species during H2O2/PI process, while O2●- radicals are the primary precursor of other reactive oxygen species. The results of this study suggested that H2O2/PI is the efficient and rapid treatment method to degrade persistent organic pollutants (POPs) from polluted wastewater sources.

Recent Advances of Using Polymer Nanocomposites For the Removal of Heavy Metal Ions From Waste Water: A Review

A major factor in the development of modern environmental engineering is the necessity of treating water pollutants. The effective removal of metallic ions of wastewater systems, using adsorption techniques, different adsorbents have been widely utilized; among these adsorbents, polymer-based composites have garnered a lot of interest due to their characteristics of environmental harmlessness and degradability. By combining the best features of both polymer and nanocomposites can offer improved chemical, physical, mechanical, and compatibility over single polymers. The review underscores the importance of polymer-based nanocomposites in offering inventive wastewater treatment methods. A thorough examination of current research and obstacles in the field of developing nanotechnology highlights these materials' ability to address the intricate problem of heavy metal ion contamination. The removal of heavy metal ions from various wastewater sources can be accomplished sustainably and effectively by integrating nanocomposites, with an emphasis on their design and manufacture. The investigation of new advances in polymer nanocomposites for the removal of heavy metal ions lays the groundwork for further study and creativity in this crucial area of environmental engineering. Using the adaptability of polymers and the special qualities of nanomaterials, this strategy develops cutting-edge solutions to deal with the intricate problems brought on by heavy metal ion pollution. Through a focus on accuracy in the design and manufacturing of these nanocomposites, scientists and industry professionals can create materials that are specialised, effective, and can make a substantial contribution to the development of wastewater treatment systems. The purpose of this research is recent analyses and challenges in the field of nanotechnology development. The data presented in this analysis will be helpful for future efforts to design and produce polymer-based Nanocomposites for the removal of a wide range of heavy metal ions

Spatial Distribution Characteristics and Ecological Risks of Typical Drugs in the Yongjiang River Basin

In recent years, due to large-scale production and widespread use, drugs have posed a potential threat to biological and human health and have received increasing attention. The occurrence and distribution of drugs in urban rivers are influenced by various factors, such as urbanization level, population density, regional geographical and climatic characteristics, and drug consumption habits. In October 2022, the Yongjiang River Basin was divided into four sub-basins： upstream, midstream, tributaries, and downstream. A total of 20 surface water and sediment samples were collected to explore the occurrence, spatial distribution, and ecological risks of drugs in water and sediment. Among the 40 target drugs, 22 drugs were detected in water samples, accounting for 55% of the target drugs, with a maximum concentration of 207.25 ng·L-1, and 12 drugs were detected in sediment, accounting for 30% of the target drug, with a maximum concentration of 153.63 μg·kg-1. The dominant species in water samples were metabolic drugs. In sediment, the dominant species in the upstream and midstream were quinolone antibiotics, while the dominant species in the tributaries and downstream were cardiovascular drugs. Nine drugs were detected in both water and sediment, with an apparent distribution coefficient Kd value of 5.0-385 029 L·kg-1. According to the average lgKoc value, the order from highest to lowest was： sertraline hydrochloride > ofloxacin > clarithromycin > D,L-venlafaxine > roxithromycin > sulfamethoxazole > fluoxetine > metoprolol > carbamazepine. Principal component analysis was used to analyze the source of drugs in water and four principal components explained 76.24% of the variation, corresponding to a source of medical wastewater, a mixed source of domestic wastewater and aquaculture wastewater, an untreated source of rural domestic wastewater, and an agricultural non-point source. Principal component analysis coupled multiple linear regression analysis well predicted the total concentration of drugs in 20 water samples （R2 = 0.868）. Three drugs were present in the water sample that posed ecological risks, with risk quotients in the order of 1,7-dimethylxanthine > dehydrated erythromycin > carbamazepine, whereas only carbamazepine in sediment posed ecological risks. The cumulative risk quotient of multiple drugs in the water at 20 sampling sites was 1.22-16.27, all of which belonged to high risk, while the cumulative risk quotient of multiple drugs in sediment was 0.009~0.064, with no risk at site S11 and low risk at all other sites. The research results can be used to analyze the distribution mechanism of drugs between water and sediment, providing a technical basis for the prevention and control of drug pollution and environmental risks in urban rivers.

Pulsed Electrolysis for Enhanced Nitrate Reduction Reaction to Ammonia at Low Concentrations

Electrochemical nitrate (NO3 -) reduction reaction (NO3 -RR) could offer a transformative pathway to generate ammonia in a sustainable, electrified, and decentralized manner. Improving the selectivity of the electrochemical process toward desired products and minimizing competing reactions (e.g., hydrogen evolution reaction) are the major bottlenecks before widespread adoption of the technology at an industrial scale. In this talk, we present our recent efforts in leveraging various electrochemical techniques, including pulsed electrolysis, to enhance the selectivity of the process toward ammonia at low nitrate concentrations (e.g., 10 mM). We use computational and experimental techniques to pinpoint the mechanism for the improved performance of nitrate reduction reaction to ammonia under pulse electrolysis in flow-cell electrochemical systems. We characterize the catalysts and local microenvironment under pulsed electrolysis and potentiostatic conditions to understand their impacts on ammonia yield and energy efficiency of the electrochemical process. This work provides foundational knowledge and understanding of materials and processes to demonstrate electrochemical NO3 -RR to ammonia at low nitrate concentrations, enabling a paradigm shift toward green and sustainable fuel synthesis from nitrogen source and water under more realistic nitrate concentrations in various wastewater sources.

A Comprehensive Review of Advanced Treatment Technologies for the Enhanced Reuse of Produced Water

Produced water (PW) is considered to be the largest source of industrial wastewater associated with oil and gas extraction operations for industrial production. It is a mixture of organic and inorganic compounds that has high complexity in terms of various characteristics. Globally, the volume of PW is increasing along with the expansion of gas and oil fields, leading to major impacts on the environment. Existing treatment technologies involve partially treating the PW through removing the suspended solids, heavy metals, without removing organic components and re-injecting the water underground using water disposal injection wells. The treatment process consists of a primary treatment unit to remove the particles, followed a secondary biological or chemical processing treatment, while the final treatment stage involves the use of a tertiary treatment unit to improve the water quality and remove the remainder of the undesired components. Moreover, while PW is considered one of the available options to be utilized as a water source, no alternate advanced treatment options on a commercial scale are available at present due to the limitations of existing PW treatment technologies, associated with their maintainability, sustainability, cost, and level of quality improvement. As such, research focused on finding an optimal treatment approach to improve the overall process continues to be conducted, with the aim of reusing the water instead of injecting it underground. This literature review discusses the latest advanced technologies for PW treatment aimed at reusing the full stream capacity of PW and eliminating the need for wastewater disposal via injection. It is concluded that researchers should focus on hybrid treatment technologies in order to remove the pollutants from PW, effectively allowing for its reuse.

A Comprehensive Review on the Biofilm‐Mediated Removal of Nitrogen and Chemical Oxygen Demand From Different Wastewater Sources

ABSTRACTDischarging effluents with high chemical oxygen demand (COD) and nitrogen content into the environment threatens human and aquatic life. An increase in nitrogen load results in depletion of dissolved oxygen (DO), eutrophication, ecological stress, and biodiversity loss. Intake of water containing excess nitrate can cause different diseases. Conventional physicochemical nitrogen removal techniques are expensive and also generate secondary pollutants. In contrast, biological methods offer effective and economical outcomes with global acceptance. Biofilm‐based techniques have the advantages of low space requirement, resistance toward toxic shocks, and absence of sludge backflow. The carriers used in biofilm reactors allow the growth of heterogeneous microbial consortia, which can simultaneously remove COD, nitrogenous compounds, and phosphates. This review aims to summarize the outcomes of the individual lab‐scale research in this area, critically analyze the scientific findings, and understand the research gap. Conventional nitrification–denitrification and anammox have often been replaced by more efficient approaches such as simultaneous nitrification–denitrification, partial nitrification–denitrification, partial nitritation and anammox, and simultaneous partial nitrification, anammox, and denitrification. Multistage moving bed biofilm reactors have been specially designed with step feeding for complete nitrogen removal. Through anammox in a sequencing batch reactor, a high rate of denitrification could be obtained, whereas simultaneous nitrification–denitrification using a membrane bioreactor resulted in almost complete removal of nitrogen. We expect that this review will provide the direction for designing experiments on enhanced removal of nitrogen and COD from different wastewater sources using microbial biofilms.

Sewage-and fertilizer-derived nutrients alter the intensity, diversity, and toxicity of harmful cyanobacterial blooms in eutrophic lakes.

Cyanobacterial harmful algal blooms (CHABs) are promoted by excessive nutrient loading and, while fertilizers and sewage are the most prevalent external nutrient sources in most watersheds, the differential effects of these nutrient sources on CHABs are unknown. Here, we tracked CHABs and performed experiments in five distinct lakes across the Northern US including Lake Erie. Fertilizers with ammonium and orthophosphate, membrane (0.2 μm)-filtered sewage (dominated by reduced forms of nitrogen) sand-and membrane-filtered sewage (dominated by nitrate), and an inorganic nutrient solution of ammonium and orthophosphate were used as experimental nutrient sources for CHABs at N-equivalent, environmentally realistic concentrations. Phytoplankton communities were evaluated fluorometrically, microscopically, and via high throughput sequencing of the 16S rRNA gene, and levels of microcystin and the δ15N content of particulate organic nitrogen (δPO15N) were quantified. Fertilizer and both sources of wastewater increased the abundance of cyanobacteria in all experiments across all five lakes (p < 0.05 for all) whereas effects on eukaryotic phytoplankton were limited. Sand-filtered sewage contained less P, organic matter, and ammonium but more nitrate and had a 25% less potent stimulatory effect on cyanobacteria than membrane-filtered sewage, suggesting nitrification may play a role in reducing CHABs. Fertilizer increased microcystin levels and decreased the δPO15N whereas wastewater increased δPO15N (p < 0.05 for all). Microcystis was the genus most consistently promoted by nutrient sources (p < 0.05 in all experiments), followed by Cyanobium (p < 0.05 in 50% of experiments), with increases in Microcystis biomass consistently elicited by membrane-filtered wastewater. Collectively, results demonstrate that differing types of sewage discharge and fertilizers can promote CHAB intensity and toxicity, while concurrently altering CHAB diversity and δPO15N. While membrane-filtered sewage consistently favored Microcystis, the discharge of sewage through sands muted bloom intensity suggesting sand-beds may represent a tool to remove key nutrients and partially mitigate CHABs.

Innovative Approach in Sustainable Agriculture: Harnessing Microalgae Potential via Subcritical Water Extraction

Microalgae can contribute to sustainable agriculture and wastewater treatment. This study investigated Tetradesmus obliquus, grown in piggery wastewater (To-PWW), as a biostimulant/biofertilizer compared to biomass grown in synthetic medium (To-B). Subcritical water extraction was tested for disruption/hydrolysis of wet biomass, at three temperatures (120, 170, and 220 ºC) and two biomass loads (1:10 and 1:80 (g dry biomass/mL water)). Extracts were evaluated for germination, and root formation/expansion. Residues were quantified for nutrient composition to assess their biofertilizer potential and tested for their affinity to oil compounds for bioremediation.The best germination was achieved by To-B extracts at 170 ºC (1:10: 148% at 0.2g/L, 1:80: 145% at 0.5g/L). Only To-PWW extracts at 0.2g/L had a significant germination effect (120 ºC: 120-123% for both loads; 170 ºC: 115% for 1:80). To-PWW extract at 120 ºC and 1:10 significantly affected cucumber and mung bean root formation (224 and 268%, respectively). Most extracts significantly enhanced root expansion, with all To-B extracts at 1:10 showing the best results (139-181%). The residues contained essential nutrients (NPK), indicating their biofertilizer potential, helping decrease synthetic fertilizers demands. To-B residues had high affinity to toluene and diesel but lower to used cooking and car oils. To-PWW showed very low affinity to all oil compounds. Finally, all residues were only able to form stable emulsions with the used car oil. This study fully exploits the use of microalgal biomass in sustainable agriculture, producing biostimulant extracts, and residues for biofertilizer and bioremediation, from a low-cost wastewater source.

New phenanthridine-based multi-functional chemosensor for selective detection of Th4+ and Hg2+ ions in both aqueous and solid state

A new phenanthridine-based multifunctional chemosensor (L), was synthesised via a green synthetic route and characterised using FT-IR, NMR and HRMS analysis. The sensing application of L towards metal ions in both solution and solid-state was studied using UV–vis and fluorescence spectroscopy, which exhibits dual-sensing behaviour for Th4+ and Hg2+ ions with good recyclability. In aqueous acetonitrile, L showed rapid response for the detection of environmental toxic metal ions and has a very low analytical detection limit of 125.5 pM and 1.94 nM for Th4+ and Hg2+ions respectively, which is remarkably lower than the World Health Organization standard. The cation binding property of the L with Th4+ and Hg2+ions was investigated by Job plot, 1H NMR titration, HR-MS and DFT calculation. The in-situ formed ensemble L-Hg2+ was further applied in the naked-eye detection of Cys (Cystine) and His (Histidine) over other common amino acids. The utility of L for real-time detection of Hg2+ and Th4+ ions was explored in various sources of environmental water samples, test paper strips, fingerprint imaging, fluorescent ink and smartphone-assisted sensing techniques, demonstrating the promising on-site visualization of the probe in controlling the toxicity levels in wastewater sources without resorting to expensive instruments.

Advancing plastics bio-upcycling with photosynthetic microorganisms using bioengineering and bioconversion strategies

Biotechnological interventions have been increasingly adopted for addressing the persistence and recalcitrance of fossil fuel-derived plastic waste. Bioremediation through microbial and enzymatic degradation offers promising solutions, yet economic and scalability challenges persist, especially for addressing plastic waste accumulation in aquatic ecosystems. Despite recent advancements in plastic bioconversion and bio-upcycling using recombinant enzymes and microbes, current genetic and biological engineering platforms mainly employed heterotrophic chassis such as Escherichia coli and Pseudomonas putida, that are not suitable for direct cultivation using wastewater sources. Photosynthetic microorganisms like cyanobacteria and microalgae offer a sustainable alternative to the heterotrophic counterparts, in not only converting wastewater and CO2 as carbon and energy sources but also bring about carbon-neutral bioconversion potentials. Therefore, this review explores bioengineering strategies required to develop and harness the capabilities of cyanobacteria and microalgae for plastic biomineralisation. Pathway engineering in selected chassis is highlighted by detailing the metabolic pathways involved in plastic degradation where the application of growth-coupled genome editing and advanced biotechnological tools is further discussed. By integrating biofoundry-driven bioengineering strategies with growth-coupled selection, microalgal strain development can be accelerated towards achieving high substrate-to-product yields thus promoting carbon-neutral biorefinery and plastic bioconversion approaches.

Microwave-assisted CuO-modified porous ZnO nanosheet for photocatalytic degradation of organic pollutants and antibacterial inactivation

The present study investigated the development of a porous ZnO/CuO photocatalyst for photocatalytic dye degradation and antibacterial inactivation of bacteria. Porous ZnO nanosheets are prepared by calcinating inorganic-organic ZnS(en)0.5. Further, CuO was integrated on a porous ZnO nanosheet using the microwave (MW)-assisted synthesis technique. Additionally, the effect of CuO at different concentrations on the photocatalytic activity of CuO/ZnO was investigated. Under 1.5 G light illumination, an optimized ZnO/CuO-5 photocatalyst exhibited higher degradation efficiencies of 99.3 %, 98 %, and 99 % for orange II dye, methylene blue (MB), and Eosin-Y respectively. The optimized photocatalyst exhibited inactivation efficiencies of 98 % and 90 % towards Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria, after 3 h. The enhanced photocatalytic activity was attributable to a porous structure, extended visible light responsiveness, and delayed electron-hole recombination in nanostructured CuO/ZnO photocatalysts. Moreover, radical scavenger tests confirmed that superoxide radicals (•O2−) accompanied most degradation, followed by holes (h+) as minor factors. Our work suggests a simple photocatalytic interfacial engineering technique based on porous ZnO/CuO nanostructures to decompose organic chemicals and inactivate microorganisms in wastewater sources.

Photothermic-catalytic bifunctionality of boron-doped molybdenum disulfide nanosheets enabling simultaneous solar evaporation and antibiotic destruction

Exploiting efficient solar evaporators with photothermic-catalytic bifunctionality has been identified as a reliable strategy for alleviating pollutant enrichment when using organic wastewater as a water source to produce freshwater during solar evaporation. Herein, a new boron-doped molybdenum disulfide (B-MoS2) is introduced as a photoabsorber and catalytic unit to create bifunctional solar evaporator, which demonstrates synergistic process of photothermal conversion and catalytic activation to achieve simultaneous freshwater production and antibiotic destruction in tetracycline (TC)-containing wastewater with peroxymonosulfate (PMS). The B-MoS2 evaporator displays a superior evaporation rate of ∼ 2.31 kg·m−2·h−1 and a high degradation efficiency of 80.7 % within one hour for TC solution under 1-sun irradiation. The combined radical/nonradical pathways are found to dominate the TC degradation, and efficient detoxification is realized over the PMS-coupled B-MoS2 evaporator. This work provides new avenues to produce freshwater from wastewater sources with the alleviated pollutant enrichment during solar evaporation.

Co-tracing of groundwater emerging and conventional contaminants in karst area of Southwest China: Distribution, source, and source-specific health risks

Groundwater pollution, especially the co-contamination of emerging contaminants (ECs) and conventional contaminants, is increasingly recognized as a critical global concern. Karst aquifers are found throughout the world, providing critical water sources and sustaining rivers and ecosystems, and are particularly vulnerable to pollution. In this study, the characteristics of the contamination, potential sources, and source-specific health risks related to ECs and trace elements (TEs) in groundwater were investigated in Guiyang (a typical karst city in southwest China). The distribution of TEs followed a descending pattern from urban to suburban to rural areas. Interestingly, the median concentrations (217 ng/L) of Caffeine (CAF) in rural areas surpassed those in urban areas (145 ng/L) and even exceeded these in densely populated areas. Additionally, ECs and TEs in groundwater are significantly influenced by population density and land use types within a 1000-meter buffer zone around the sampling sites. Hierarchical cluster analysis and positive matrix factorization suggested that five principal sources of contamination were identified: domestic wastewater (29.7 %), industrial production (25.2 %), agricultural activities (16.3 %), natural and industrial sources (14.9 %), and pharmaceuticals (13.9 %). Monte Carlo simulations revealed that the non-carcinogenic risks to children in urban areas are significant, with 30.0 % of these risks exceeding the safety threshold. Source-specific health risk assessments indicated that industrial production is the primary source of risk. Furthermore, this study introduces a co-tracing method to trace the sources of groundwater contamination in karst systems. The co-tracing method based on the ECs and TEs allows for a deeper understanding of contaminant transfer and its fate in karst groundwater.

Fabrication of a novel robust gelatine-based poly-cationic flocculant with dual flocculation and bactericidal functions for manure wastewater treatment

Manure suspended solids and pathogens negatively contribute to many environmental aspects including water contamination, air pollution, greenhouse gas emissions (GHG), unpleasant odor and spread of pathogenic bacteria. Production of an environmentally friendly flocculant with dual function of sterilization and flocculation of the manure solids and particles is a challenge. Here, gelatin (Gel) was covalently modified with non-vinyl monomer, glycidyltrimethylammonium chloride (GMTA) to form poly-cationic Gel (GMTA@Gel) via a single step functionalization under mild conditions. The developed cationic Gel (GMTA@Gel) showed positive zeta potential (ZP) value > +50 mv in a wide pH range (3−10), excellent removal efficiency of total suspended solids (97 %) and E. coli (98 %) in dairy wastewater, and disinfection capability of microorganisms adsorbed on the Gel, which were confirmed by elemental analysis and cell rupture analysis. The developed Gel-based flocculant showed 95 % removal of both MSS and E. coli from real manure wastewater collected from manure ponds of dairy farms in Central Valley, California and reduced 97 % of volatile solids, which suggest its contribution in reducing GHG emissions. The developed GMTA@Gel flocculant has the advantages of environmental protection, excellent removal efficiencies for anionic contaminants and enhanced coagulation effect on suspended bacterial cells and particles which suggest GMTA@Gel to be applied on removal of suspended anionic suspensions (particles or cells) from various wastewater sources.

Machine learning-assisted source tracing in domestic-industrial wastewater: A fluorescence information-based approach

An emergency water pollution incident poses a significant risk to the proper functioning of wastewater treatment plants, particularly in domestic-industrial integrated facilities. Source tracing is recognized as an effective method to mitigate ongoing impacts. Machine learning-assisted traceability is emerging as a more efficient and faster method compared to traditional methods. In this study, a total of 712 sets of characterization wastewater information from effluent samples from14 discharge enterprises across 6 different sectors, as well as domestic wastewater was collected using 3-dimensional fluorescence spectroscopy. After data cleaning and augmentation, a feature fingerprint database of wastewater was constructed to train a traceability model. Several machine learning algorithms, including Back Propagation neural network (BP), Random Forest (RF), Support Vector Machine (SVM), Naive Bayes (NB) and K-Nearest Neighbors (KNN), were selected for constructing the traceability framework. Subsequently, an advanced Particle Swarm Optimization Random Forest model (PSO-RF), capable of automatically optimizing model parameters, was proposed and applied to trace the sources of wastewater in integrated wastewater treatment plant. The PSO-RF achieved and accuracy of 96.55 % in sector identification and 94.25 % in manufacturer identification. As part of the validation process, laboratory simulations were conducted using blended wastewater with different volume ratios of domestic and industrial wastewater to evaluated the potential application of PSO-RF. The results consistently demonstrated PSO-RF's effectiveness, particularly in tracing pharmaceutical wastewater sources, maintaining an accuracy of over 85 %. This work presents a novel strategy for tracing abnormal sources during emergency pollutant incidents, providing essential support for integrating artificial intelligence (AI) into meticulous wastewater management.

Analyzing Antibiotic Resistance in Bacteria from Wastewater in Pakistan Using Whole-Genome Sequencing.

Background: Wastewater is a major source of Antibiotic-Resistant Bacteria (ARB) and a hotspot for the exchange of Antibiotic-Resistant Genes (ARGs). The occurrence of Carbapenem-Resistant Bacteria (CRB) in wastewater samples is a major public health concern. Objectives: This study aimed to analyze Antibiotic resistance in bacteria from wastewater sources in Pakistan. Methods: We analyzed 32 bacterial isolates, including 18 Escherichia coli, 4 Klebsiella pneumoniae, and 10 other bacterial isolates using phenotypic antibiotic susceptibility assay and whole-genome sequencing. This study identified the ARGs, plasmid replicons, and integron genes cassettes in the sequenced isolates. One representative isolate was further sequenced using Illumina and Oxford nanopore sequencing technologies. Results: Our findings revealed high resistance to clinically important antibiotics: 91% of isolates were resistant to cefotaxime, 75% to ciprofloxacin, and 62.5% to imipenem, while 31% showed non-susceptibility to gentamicin. All E. coli isolates were resistant to cephalosporins, with 72% also resistant to carbapenems. Sequence analysis showed a diverse resistome, including carbapenamases (blaNDM-5, blaOXA-181), ESBLs (blaCTX-M-15, blaTEM), and AmpC-type β-lactamases (blaCMY). Key point mutations noticed in the isolates were pmrB_Y358N (colistin) and ftsI_N337NYRIN, ftsI_I336IKYRI (carbapenem). The E. coli isolates had 11 different STs, with ST410 predominating (28%). Notably, the E. coli phylogroup A isolate 45EC1, (ST10886) is reported for the first time from wastewater, carrying blaNDM-5, blaCMY-16, and pmrB_Y358N with class 1 integron gene cassette of dfrA12-aadA2-qacEΔ1 on a plasmid-borne contig. Other carbapenamase, blaNDM-1 and blaOXA-72, were detected in K. pneumoniae 22EB1 and Acinetobacter baumannii 51AC1, respectively. The integrons with the gene cassettes encoding antibiotic resistance, and the transport and bacterial mobilization protein, were identified in the sequenced isolates. Ten plasmid replicons were identified, with IncFIB prevalent in 53% of isolates. Combined Illumina and Oxford nanopore sequencing revealed blaNDM-5 on an IncFIA/IncFIC plasmid and is identical to those reported in the USA, Myanmar, and Tanzania. Conclusions: These findings highlight the environmental prevalence of high-risk and WHO-priority pathogens with clinically important ARGs, underscoring the need for a One Health approach to mitigate ARB isolates.

Porous rGO-MBene monolith: A highly efficient solar evaporator for salt-resistant desalination and multitasking water purification

Solar-driven water evaporation for sustainable freshwater production is an efficient and economical solution to alleviate global water shortages. However, available solar evaporators still face efficiency and durability limitations. Herein, this challenge is overcome via the ingenious design of a three-dimensional (3D) monolithic porous architecture based on the reduced graphene oxide (rGO) and layered molybdenum boride (MBene). Benefiting from broad light absorption, efficient water activation and porous architecture feature, the rGO-MBene acquires an impressive rate of ~2.79 kg·m−2·h−1 to steam pure water under one-sun (1 kW/m2), which is superior to most of state-of-the-art graphene-based evaporators reported so far. When applied to solar desalination, the rGO-MBene exhibits highly durable desalination capability with a salt-free evaporation surface. After continuous irradiation in a 3.5 % NaCl solution for 100 h, an almost constant evaporation rate of approximately 2.34 kg·m−2·h−1 can be maintained. Meanwhile, the rGO-MBene evaporator also demonstrates its robustness for effective production of freshwater from various wastewater sources. This work not only establishes an attractive example of rGO-hybridized architecture to achieve highly efficient solar evaporation for long-lasting salt-resistant desalination and multitasking water purification, but also provides exciting opportunities to design new MBene-based materials with the improved photothermal performance for sustainable solar conversion.

Antibacterial of PSf substrate and PA active layer of TFN membrane made by POM/3-API hybrid in situ FO separation performance and photo-degradation of organic pollutant

Membrane bacterial studies are stable in modified FO membrane that shows superior antibacterial activity against Tetrasphaeria (minimal inhibitory concentration (MIC) = 0.00350, 0.11 μg/mL). Due to augmented interventions of the containments in the water resources, essential novel hybrids construct of polyoxometalate with imidazole for the separation process and photo catalytic degradation of organic pollutants have been recognized and scouted in this paper. This work demonstrated the separation and photocatalytic extraction of the organic pollutants from the potable and waste water using organo-polyoxometalate ionic salts as hybrids designated as polyoxometalate with 3-(aminopropyl) imidazole (POM/3-API). Hybrid materials are strategically prepared in one-pot via counter acidic proton exchange between POM (O- ions) which tends to move towards N- containing organic molecules, which are doped with manganese (IV) ions. Scanning Electron Microscope (SEM) studies show physico-chemical adsorption of the hybrids, PSf substrate and on PA layer of membranes, proving the multifunctional surface characteristics morphological formation. In addition, POM/3-API hybrids were synthesized via shock acoustic that reveals higher permeate flux through separation process and almost disappears (PAPI-1: 81.4 %) with MO during degradation process. Remarkably, the morphological changes of observed shapes before and after MO clearly show an effective performance, as was definite by the successful interfacial polymerization between membrane and POM/3-API. These help towards elimination of MO dyes at waste water sources, making the process environment-friendly.