Wastewater Recycling Research Articles

Study on the mechanism of sodium ion inhibiting citric acid fermentation in Aspergillus niger

Excessive sodium significantly inhibits citric acid fermentation by Aspergillus niger during the recycling of citric acid wastewater. This study aimed to elucidate the inhibition mechanism at the interface of physiology and transcriptomics. The results showed that excessive sodium caused a 22.3 % increase in oxalic acid secretion and a 147.6 % increase in H+-ATPase activity at the 4 h fermentation compared to the control. Meanwhile, a 13.1 % reduction in energy charge level and a 15.2 % decline in NADH content were found, which implied the effects on carbon metabolism and redox balance. In addition, transcriptomic analysis revealed that excessive sodium altered the gene expression profiles related to ATPase, hydrolase, and oxidoreductase, as well as pathways like glyoxylate metabolism, and transmembrane transport. These findings gained insights into the metabolic regulation of A. niger response to environmental stress and provided theoretical guidance for the construction of sodium-tolerant A. niger for industrial application.

Photothermal self-floating aerogels based on chitosan functionalized with polydopamine and carbon nanotubes for removal of arsenic from wastewater

Although wastewater disposal in evaporation ponds may be a cost-effective strategy for wastewater management, it overlooks water recycling and can possibly pose significant threats to the surrounding environment. The development of photothermal materials with functional groups capable of adsorbing toxic contaminants offers a promising opportunity for detoxification and potentially solar-driven recycling of wastewater disposed in evaporation ponds. In this study, ultralight aerogels based on chitosan (Ch), a natural biodegradable polymer, functionalized with mussel-inspired polydopamine (PDA) and carbon nanotubes (CNT) were fabricated through a facile approach and examined for the removal of arsenic from water. Three aerogels, namely chitosan, CNT/Ch, and PDA@CNT/Ch were fabricated and characterized using SEM, FTIR, TGA, XPS, and BET surface area analysis. Adsorption isotherms, thermodynamics, and kinetics were systematically investigated, revealing the feasibility of the fabricated aerogels for arsenic removal from aqueous solutions. The UV–Vis and photothermal analysis indicated excellent light-absorption and light-to-heat conversion performance of the functionalized aerogels. Arsenic adsorption by aerogels occurred rapidly and reached equilibrium within 30 to 60 min and was well-fitted by pseudo second-order kinetics model. The Langmuir model well described the adsorption isotherm, and the maximum adsorption capacities were found to be 31.5, 36.6, and 38.7 mg/g at neutral pH for chitosan, CNT/Ch, and PDA@CNT/Ch, respectively. The adsorption mechanism was studied by FTIR and XPS analysis and the adsorption pathway was evaluated using intraparticle diffusion model. This study broadens the scope of utilizing aerogels for the detoxification and potential recycling of wastewater from diverse sources and effluents disposed in evaporation ponds.

Surface implantation of ionically conductive polyhydroxyethylaniline on cation exchange membrane for efficient heavy metal ions separation

Extraction of heavy metal ions from aqueous could enable recycling of wastewater and reusing of high-value ion resources. Recently, electrodialysis (ED) technology has been applied in the removal of heavy metal ions from wastewater, however, developing high-efficient and stable heavy metal ions selective cation exchange membrane (CEM) remains an elusive challenge. Herein, we demonstrate the fabrication of high-efficient cations selective CEM with the surface implantation of ionically conductive polyhydroxyethylaniline (PANI-OH) on a commercial CEM membrane (CTG) containing sulfonic acid groups via the electrostatic attraction. Implanted hydrophilic and positively charged PANI-OH facilitates fast and selective transfer of Cu2+ over Zn2+ cations through the membrane. Meanwhile, the synergistic effect of rigid conjugate structure and hydrogen-bond interaction of PANI-OH renders the resultant membrane CTG-PANI-OH with stable structure and separation performance. As such, the Cu2+/Zn2+ permselectivity of CTG-PANI-OH membrane is ~1.70, which is about 190 % of that of the pristine CTG membrane. This work provides a facile design and strategy for the construction of high-efficient cations selective CEMs with great application prospects in the purification and extraction of heavy metal ions from wastewater.

Effect of recycling treated effluent on the cultivation of Scenedesmus sp. in anaerobically digested abattoir effluent (ADAE)

This waste-to-profit study evaluated the recycling of treated effluent as a source of dilution water for the cultivation of Scenedesmus sp. in anaerobically digested abattoir effluent (ADAE) under outdoor conditions over 3 months. Despite biomass productivity of Scenedesmus sp. trending lower for ADAE grown cultures diluted with recycled wastewater (RWW) than freshwater (FW) at the beginning (Week 2–8), RWW grown cultures subsequently recovered and showed significantly higher productivity (28–55 %) during the remaining study (Week 10–15). A similar outcome was also observed for the photo-physiology and ammonia removal rates of Scenedesmus sp. in both treatments. Weekly ammoniacal nitrogen removal efficiency ranged between 70 and 100 % for FW and 38–98 % for RWW. Although bacterial load, the concentration of dissolved & suspended solid, total organic carbon and trace metals was higher in the RWW culture than the FW, no negative effect was seen on the growth and bioremediation capacity of Scenedesmus sp.. Overall, this study clearly demonstrated the recycling of treated wastewater to be efficient for treating ADAE using Scenedesmus.

ANALYSIS OF METHODS FOR ASSESSING THE IMPACT OF A COKE PLANT ON THE ENVIRONMENT

This academic paper explores various assessment methods used to evaluate the environmental impact of industrial enterprises, specifically focusing on coke plants. The study emphasises the widespread use of a global risk-based approach for assessing the environmental risks posed by such enterprises to both the environment and public health. This approach involves predicting potential future environmental consequences under different scenarios, with the choice of a specific method dependent on the particular conditions, objectives, and available resources.The analysis of these assessment methods reveals the prevalence of an integrated approach, which comprehensively evaluates multiple aspects of an industrial enterprise’s environmental impact. Moreover, the research underscores the importance of adopting modern technologies and strategies to enhance water supply and wastewater management efficiency for environmental preservation.The assessment of the ‘Kharkiv Coke Plant’ indicates minimal impact on land inundation issues, with little effect on groundwater quality. However, the excessive consumption of freshwater remains a significant concern, necessitating improved efficiency in the operation of the plant’s wastewater recycling systems. To evaluate the enterprise’s influence on surface waters, notably the Lopan and Udy rivers, the paper calculates the volume and flow of wastewater originating from the facility’s premises.Additionally, environmental impact assessment is conducted using key environmental indicators, including the alarm index, hazard index, and priority index. In light of the identified environmental challenges at the investigated industrial facility, including wastewater discharge into the municipal sewerage system, high water consumption, and phenol emissions from the quenching tower, the paper proposes a solution. This solution entails enhancing the plant’s water recycling infrastructure through the implementation of a closed-loop water recycling system and improving the efficiency of the biochemical plant. This approach aims to mitigate the environmental impact of the enterprise while promoting sustainable water management practices. Keywords: environmental problems, water resources, degree of pollution, enterprises.

Prediction of drought in lake mead

Lake Mead is a reservoir on the Colorado River on the border of Nevada and Arizona. It is the largest reservoir in the United States. Due to the drought caused by climate change and the increasing water demand of the population served by Lake Mead, the capacity of this reservoir has been greatly reduced. The continuous water shortage has had a huge impact on the surrounding cities, and people are preparing to adopt wastewater recycling. To alleviate the shortage of water sources. this paper uses the water level data of the past years to establish a grey forecast Grey Model (1,1) model to predict the changes in the water level of Lake Mead in the next 30 years and compares them based on the prediction of short-term and long-term drought data. based on the previous survey of wastewater sources and collection methods, it is believed that the wastewater recovery system is mainly affected by four factors: financial support, collection pipe network coverage, treatment technology, and wastewater classification capabilities.

Morphology analysis and microbial diversity in novel anaerobic baffled reactor treating recycled paper mill wastewater

Morphology analysis and microbial diversity in novel anaerobic baffled reactor treating recycled paper mill wastewater

Sustainable Utilization of Pulp and Paper Wastewater

The pulp and paper industry plays an important role in the global economy and is inextricably linked to human life. Due to its large scale, the production process generates a large amount of wastewater, which poses a major threat to the environment. The sustainable utilization and safe treatment of pulp and paper wastewater can effectively reduce environmental pollution, improve resource utilization efficiency, protect water resources, provide economic benefits for pulp and paper enterprises, and thus promote the green and sustainable development of the pulp and paper industry. Therefore, this study discusses the pollution components of pulp and paper wastewater and their impact on the environment and human health. In this review, we aim to explore the sustainable development of pulp and paper wastewater by summarizing the characteristics of current pulp and paper wastewater, the commonly used treatment methods for pulp and paper wastewater, the application of pulp and paper wastewater recycling, and the future development direction of pulp and paper wastewater.

An Integrated Approach for Biodegradation of Toxic Azo Dyes and Wastewater Recycling by Azoreductase Gene–Harboring Bacillus paramycoides Strain AM-3

An Integrated Approach for Biodegradation of Toxic Azo Dyes and Wastewater Recycling by Azoreductase Gene–Harboring Bacillus paramycoides Strain AM-3

Microplastics in aquatic bodies: Assessing the role of governance mechanisms in industrial wastewater management

The purpose of this research is to examine the association between corporate governance mechanisms (board independence, board gender diversity, Chief Executive Officer (CEO) duality, and environmental, social and governance (ESG) linked compensation) and wastewater recycling as a strategy for managing the flow of microplastics into the aquatic environment. The study analysed an international sample of top companies on the Forbes 500 list over a 15-year period during the millennium development goals (MDGs) and sustainable development goals (SDGs) eras. Multiple regression analysis with fixed effect OLS, two-stage least squares regression, propensity score matching, and logistic regression were applied in the data analysis. The results show that, at the aggregate level, board gender diversity is positively associated with wastewater recycling, whilst CEO duality has a significant negative impact. When disaggregated into industries, board gender diversity is positively associated with wastewater recycling in high-polluting and low-polluting industries. In relation to the MDGs/SDGs eras, the impact of board gender diversity is more significant in the MDGs era than in the SDGs era. At the geographical region level, CEO duality has a significant negative impact on wastewater management in the America and Asia Pacific regions, whilst the effect of CEO duality is significantly positive in the Western Europe region. We also find that a minimum of two female directors is required to improve wastewater management practice. The study concludes that whilst board gender diversity is a notable driver of wastewater management, CEO duality diminishes the commitment of multinational entities (MNEs) to addressing wastewater management issues. Our result is robust to (i) alternative measures of wastewater management, (ii) alternate sample composition, (iii) alternate method of data analysis, and (iv) endogeneity checks. The study contributes to the limited literature on waste management and the circular economy, particularly governance mechanisms’ role in wastewater management in an international context.

Transformation of struvite from wastewater to a hydrogen fuel storage compound ammonia borane.

Ammonia borane (NH3BH3) is a carrier of hydrogen gas that is known as a carbon-free renewable energy source. A high hydrogen content of ammonia borane and its stability in air at ambient temperatures make it a valuable molecule for its potential use as a hydrogen storage compound. In this study, we investigate a new approach for synthesizing ammonia borane using wastewater-derived ammonia source. Wastewater recycling has always been a global interest towards sustainability. In addition to reclaiming the water, recycling nutrients in wastewater is a topic of interest. Nutrients such as nitrogen, magnesium, and phosphorous are readily recovered from wastewater as struvite (NH4MgPO4·6H2O). This new process involves converting urine into struvite, and then reacting struvite with alkali borohydrides to produce a high-purity ammonia borane. The use of mild reaction conditions without extensive purification process, together with high purity ammonia borane product make this process a desirable course of action for recycling the nitrogen waste. In the course of moving towards a sustainable environment, the energy and wastewater industries will benefit from this combined process of nitrogen removal from wastewater to generate a renewable carbon-free energy molecule.

A sulfide self-driven fuel cell for H2O2 electrosynthesis and sulfur recycling

An energy-free method is developed to produce H2O2 directly from air and sulfur from sulfide-contained wastewater simultaneously. The sulfide self-driven fuel cell can recycle chemical energy into electric energy and sulfide contaminants to sulfur. The H2O2 electrosynthesis strategy is no need for external energy or fuels, which is driven by the electrical energy from sulfide pollutants oxidation. The fuel cell exhibits excellent battery performances, e.g. the highest open cell voltage of 1.29 V and a running current of >100 mA cm−2 at 0 V. The initial current efficiency for H2O2 is 97.94 ± 1.85 %. For wastewater and air tests, the fuel cell can produce 24.75 ± 0.35 mmol L−1 H2O2 solution within 10 h, with an average productivity of 0.37 ± 0.03 mmol cm−2 h−1. It not only can recover the resource and energy from pollutants but also reduce the production energy consumption. The excellent two-electron route oxidation performances of sulfide are proven using in-situ electrochemical technology. This attempt can shed light on H2O2 electrosynthesis and the recycling of sulfide-contained wastewater.

Public tap water perceptions and potable reuse acceptance: A cognitive dissonance theoretical understanding

Water scarcity is a pressing issue caused by many factors, including urban water demand, poor wastewater management, and climate change. To address this growing issue, wastewater recycling for potable use is encouraged worldwide. Planned potable reuse (PPR) involves reusing treated wastewater intentionally as a drinking water source. PPR promotes a circular water economy and reduces local water shortages. However, public acceptance of PPR remains low due to the psychological disgust associated with consuming treated wastewater, known as the yuck factor. Traditional educational marketing campaigns have been ineffective in increasing PPR acceptance, necessitating further investigation into other approaches to do so. This study analyzes whether consumers’ perceptions about their current tap water significantly links to their attitudes toward PPR. Guided by the cognitive dissonance theoretical framework, our study examines if public tap water customers who (1) already believe their drinking water contains treated wastewater (de facto reuse) and (2) trust their public water suppliers (PWS) are more likely to accept PPR. Two separate survey-based studies were conducted in 2019 and 2020 on adult public water consumers in the US. Statistical analyses reveal that those participants who believe their tap water contains de facto reuse water, have high trust in their PWS, or primarily consume tap water (behavioral trust) demonstrate greater acceptance of PPR. Additionally, our results suggest that acceptance toward PPR increased after the COVID pandemic, but this effect is moderated by gender. Overall, our study results indicate that addressing cognitive dissonance in consumer attitudes toward PPR may lead to more sustainable solutions for water management in the US. Further research should explore the interplay between de facto reuse beliefs, trust, and PPR acceptance, to enable the development of effective prosocial marketing strategies that can overcome the yuck factor and ultimately promote wider consumer acceptance of PPR.

Surface modification of FeⅢ-juglone coating on nanofiltration membranes for efficient biofouling mitigation

Nanofiltration membranes have increasingly played a vital role in the purification of surface water and the recycling of wastewater. However, the problem of membrane biofouling, which leads to shortened service life and increased energy consumption, has hindered the widespread application of nanofiltration membranes. In this study, we developed functionalized nanofiltration membranes with anti-adhesive and anti-biofouling properties by coordinating FeIII and juglone onto commercial nanofiltration membranes in a facile and viable manner. Due to the hydrophilic nature of the FeⅢ-juglone coating as well as its ultra-thin thickness and minimal impact on the membrane pores, the permeance of the optimally modified membrane even increased slightly (14 %). The outstanding anti-adhesive property of the FeⅢ-juglone coating was demonstrated by a significant reduction in the adsorption of proteins and bacteria. Furthermore, the modified membranes exhibited lower flux decline amplitude and reduced biofilm deposition during dynamic fouling experiment, further supporting the outstanding anti-biofouling performance of the nanofiltration membrane after the modification with FeⅢ-juglone coating. This study presents a novel and feasible approach for simultaneously improving the water permeance, anti-adhesive property and anti-biofouling property of commercial nanofiltration membranes.

Datacentric Similarity Matching of Emergent Stigmergic Clustering to Fractional Factorial Vectoring: A Case for Leaner-and-Greener Wastewater Recycling

Water scarcity is a challenging global risk. Urban wastewater treatment technologies, which utilize processes based on single-stage ultrafiltration (UF) or nanofiltration (NF), have the potential to offer lean-and-green cost-effective solutions. Robustifying the effectiveness of water treatment is a complex multidimensional characteristic problem. In this study, a non-linear Taguchi-type orthogonal-array (OA) sampler is enriched with an emergent stigmergic clustering procedure to conduct the screening/optimization of multiple UF/NF aquametric performance metrics. The stochastic solver employs the Databionic swarm intelligence routine to classify the resulting multi-response dataset. Next, a cluster separation measure, the Davies–Bouldin index, is used to evaluate input and output relationships. The self-organized bionic-classifier data-partition appropriateness is matched for signatures between the emergent stigmergic clustering memberships and the OA factorial vector sequences. To illustrate the proposed methodology, recently-published multi-response multifactorial L9(34) OA-planned experiments from two interesting UF-/NF-membrane processes are examined. In the study, seven UF-membrane process characteristics and six NF-membrane process characteristics are tested (1) in relationship to four controlling factors and (2) to synchronously evaluate individual factorial curvatures. The results are compared with other ordinary clustering methods and their performances are discussed. The unsupervised robust bionic prediction reveals that the permeate flux influences both the UF-/NF-membrane process performances. For the UF process and a three-cluster model, the Davies–Bouldin index was minimized at values of 1.89 and 1.27 for the centroid and medoid centrotypes, respectively. For the NF process and a two-cluster model, the Davies–Bouldin index was minimized for both centrotypes at values close to 0.4, which was fairly close to the self-validation value. The advantage of this proposed data-centric engineering scheme relies on its emergent and self-organized clustering capability, which retraces its appropriateness to the fractional factorial rigid structure and, hence, it may become useful for screening and optimizing small-data wastewater operating conditions.

Efficient treatment of surfactant containing wastewater by photocatalytic ozonation with BiPO4 nanorods

In this study, monoclinic BiPO4 nanorods were fabricated by one-pot solvothermal method. Its catalytic capability in photocatalytic ozonation process was tested by degradation and mineralization of sodium dodecyl benzene sulfonate (SDBS) solution. The results demonstrated that the TOC removal rate was dramatically improved to 90.0% at 75 min for UV/O3/BiPO4 process, which was 4.9 and 3.8 times more than that of UV/BiPO4 and O3. Moreover, the pseudo-first-order kinetic constant (0.337 min−1) and mineralization rate (90.0%) for SDBS degradation using BiPO4 in UV/O3 process were 1.6 and 1.3 times as great as that of conventional TiO2 photocatalyst (0.206 min−1, 67.3%). The influence of BiPO4 dosage, O3 concentration initial pH and coexisted ions on SDBS degradation in UV/O3/BiPO4 process were also investigated. The outcome of quenching studies illustrated both ·OH and h+ contributed prominently to SDBS degradation in UV/O3/BiPO4 process, implying that high valence band position of BiPO4 could promote the synergism between photocatalysis and ozonation. The degradation pathway of SBDS was proposed by combination of intermediates analysis and DFT calculation. Real carwash wastewater was chosen as typical surfactant containing wastewater to explore the practical application of UV/O3/BiPO4 technology. During 30 min, COD and LAS removal efficiency reached 59.7% and 70.6%, respectively. The quality indices of effluent could meet the requirements for reuse of carwash water in Water Quality Standard for Urban Miscellaneous Use in China. Energy consumption in the process was calculated as 13.9 kW h m−3, which was about 3.6 and 2.2 times less than that of UV/BiPO4 and O3 process, respectively. The results suggest that UV/O3/BiPO4 system has an application potential for surfactant containing wastewater treatment or recycle.

Bacteriovory of enteric bacteria by soil isolated amoeba depends on both temperature and salinity

Recycling of wastewater for agricultural irrigation is an important means for sustainable reuse practices, but a major concern of such practice is the introduction of pathogens and antibiotic determinants. Previous attempts to mitigate contaminants focused on water treatment, yet the growing appreciation of the soil microbial food web brings into focus its potential to mitigate pathogens introduced by recycled effluent. We hypothesized that effluent-introduced bacteria serve as prey to soil-free living amoeba (FLA), but predation is interfered with by environmental conditions such as temperature and/or salinity. To test our hypothesis, we first demonstrated that an enteric bacterium model, Escherichia coli, is preyed on by soil FLA. We then isolated 12 FLA from three soil types (loamy-sand, loam, and clay) and followed the predation dynamics in three prey types: E. coli, Serratia marsescens, and Enterococcus mundtii. Predation was simulated in an unstructured environment at various temperatures (20, 25, 30 °C), mimicking changing climatic conditions and salinities (2, 10, 30 mM NaCl), mimicking the relative ionic strength and conductivity applied by irrigation effluent. We found that the predation efficiency of the amoeba strains increased significantly increased (p < 0.01) at both low temperature (20 °C) and high salinity (30 mM NaCl) regardless of the types of prey. We suggest that increased salinity applied by effluent irrigation may benefit micropredators, while high temperatures may increase resistance to predation. Our results demonstrate the importance of understanding the effects of environmental conditions on soil trophic interactions and their potential benefits for agricultural practices.

Water Resources Management in Practices at National Pingtung University of Science and Technology Campus

NPUST was the top Taiwan university for the 9th consecutive year on the UI GreenMetric World University Ranking, and placed 27th out of 1,050 schools from 85 countries. This achievement is the result of our commitments to sustainable development. NPUST has been building green transportation for carbon and air pollution reduction, green energy system for effective use of electricity generated by renewable energy, and campus waste water recycling system for the goal of zero discharge. We also implement policies on waste reduction and waste sorting and recycling, as well as encourage planting in school campus. The practice of water resources management is crucial in various aspects that contribute to this sustainable campus. The sustainable management strategies include water consumption management, water conservation and water saving, and water recycling management. In this paper, we are going to share our practical experience in waste water treatment, recycling system set-up, waste water reuse, sustainable development for water resources and how we implement the policies on water saving at campus and spread water resources knowledge. The information is provi

Perspectives for the green hydrogen energy-based economy

Hydrogen as an energy vector offers enormous potential compared to other renewable energy routes in the deep decarbonization of industrial sectors. However, globally, developments across the entire hydrogen value chain are still emerging. The specific facets of hydrogen energy, like production, storage, transportation, applications, and policies, are individually evaluated. Nevertheless, a comprehensive viewpoint on the prospects and challenges across the entire hydrogen value chain is essential, and such holistic information is rare. This study addresses the knowledge gap by mapping the potential of the hydrogen economy from an all-rounded perspective. In addition to the advancements in materials, wastewater recycling and the use of microbes or enzymes in electrolysis, offer potential alternative routes to support a hydrogen-based economy. Significant technological advancements are warranted for safe hydrogen transportation and storage. A vast network of refueling stations is essential for hydrogen fuel penetration in the transportation sector, and conducive governing policies are needed to decarbonize heavy industries. Lastly, government incentives are crucial to promote the socioeconomic acceptance of the transition from fossil fuels to green hydrogen.

Preparation of Biomass Carbon Composites MgO@ZnO@BC and Its Adsorption and Removal of Cu(II) and Pb(II) in Wastewater.

The ternary composite MgO@ZnO@BC was synthesized and characterized for the adsorption of Cu2+, Pb2+ heavy metal ions from wastewater. The results show that the addition of the MgO@ZnO@BC composite results in higher adsorption properties for Cu2+ and Pb2+, with a molar ratio of 5% 0.1 g, and maximum adsorption capacity (50.63 mg/g for Cu2+ and 61.46 mg/g for Pb2+). The Langmuir adsorption isotherm of the adsorption complex and the kinetics of adsorption are secondary kinetics. The adsorption of Cu2+ and Pb2+ was mainly chemisorption, accompanied by physical adsorption. This adsorption method fully conforms to the concepts of clean production and efficient waste utilization, providing a reference for the removal of heavy metal ions from wastewater and waste recycling using ternary composite materials.