Utilization In Wastewater Treatment Research Articles

Innovations in nanomaterial-embedded polymer membranes for water and wastewater treatment: a comprehensive review

Abstract There has been growing interest in advancing nanoparticle-embedded polymeric membranes and their significant utilization in wastewater treatment to address the global water pollution problem. Incorporation of nanomaterials into the membrane matrices not only enhances the physicochemical properties like hydrophilicity, mechanical and thermal stability, porosity, antifouling, and antibacterial properties of the polymers but also influences the membrane permeability, selectivity, and several contaminant removals. This overview highlighted the development of nanomaterials like metal/metal oxide nanoparticles (0D), carbon nanotubes (1D), graphene or graphene oxide (GO) (2D layer materials), zwitterionic, zeolites, and associated structures (3D) blended with significant polymeric materials, along with synthesis and integration techniques for fabricating mixed-matrix nanoparticle-embedded polymer nanocomposite (PNC) membranes. This article also addresses the limitations of conventional water treatment technologies, recent challenges of polymer membrane technology, environmental impact, human considerations, and the prospects of these advanced nanoparticle-embedded polymer membranes for sustainable water and wastewater treatment. The motivation for future research in polymeric materials with embedded nanoparticles and the prediction of novel membranes for water purification will also be provided.

Vesicular BiVO4 nanostructures modified by g-C3N4 quantum dots for enhanced photocatalytic activity

Photocatalysis technology has been an available method to alleviate the improper discharge of dye wastewater by employing light energy to degrade the dye pollutants. Here, the vesicular BiVO4 hollow structures were modified by graphite phase carbon nitride quantum dots (CNQDs) to construct the BiVO4-based photocatalyst (BiVO4/CNQDs) for the enhanced removal of dye molecules. The CNQDs with a diameter of 2–5 nm evenly decorate on BiVO4 vesicles to construct the close interface of the BiVO4/CNQDs heterojunctions. Compared with vesicular BiVO4, the enhanced visible-light decomposition of methyl orange (MO) comes down to the coordination of different components, the C and/or N doping and hollow structure. This is helpful to increase surface area of bulk BiVO4, broaden light response, narrow band gap and obstruct charge combination. Especially, the up-conversion luminescence of the CNQDs can induce BiVO4 to generate more photo-excited electrons to participate in the MO photo-degradation reaction. The BiVO4/CNQDs heterojunctions with the unique hollow structure and excellent photocatalytic activity display the promising utilization in wastewater treatment.

Modified Gasification-Slag-Driven Persulfate Activation for Highly Efficient Degradation of Acetaminophen: N/O Active Site Regulation and Nonradical Oxidation

With the development of coal chemical technology, a large amount of gasification slag and wastewater are produced through coal gasification. Efficient gasification slag utilization and wastewater treatment have attracted much attention. In this study, gasification slag was modified and used as a low-cost and efficient catalyst to activate persulfate for acetaminophen degradation. Via the analysis of high-resolution X-ray photoelectron spectroscopy, the surfaces of nitric acid and calcined modified gasification slag retained a considerable number of carbonyl and graphite N functional groups. These proved to be effective active sites for the activation of persulfate. X-ray diffraction analysis revealed that the gasification slag was composed of carbon and SiO2. The evaluation of catalytic activity and application of density functional theory proved that the interaction between carbonyl and graphitic nitrogen significantly affected the catalyst activity. When the ratio of graphitic nitrogen to carbonyl was 1:3, the adsorption and activation of persulfate were significantly enhanced. The results of the quenching experiments also confirmed that the non-free radical pathway is the main pathway to activate persulfate using the gasification slag. This study provides a new approach to industrial waste utilization in wastewater treatment.

Long-term impact of nano zero-valent iron on methanogenic activity, microbial community structure, and transcription activity in anaerobic wastewater treatment system

Nano zero-valent iron (NZVI) is commonly used in industrial wastewater treatment. However, its long-term impact mechanisms of metabolization in anaerobic systems are not well understood. This study investigated the effects of long-term and continuous addition of NZVI on methanogenic activity, microbial community, and transcription activity. The results demonstrated that low levels of NZVI (1000 mg/L) induced inhibition of methanogenesis after 80 days, while high levels of NZVI (5000 mg/L) immediately led to a sharp decrease of cumulative methane production and chemical oxygen demand removal, which arrived at a steady state (14.4 % of control and 17 %) after 30 days. NZVI adversely affected cell viability, adenosine triphosphate production, and fatty acid evolution of cell membranes played a crucial role in resisting chronic NZVI toxicity. Moreover, high NZVI levels hindered the transcription of key enzymes CoM and mcrA, while low NZVI levels maintained its high CoM and mcrA activity, but down-regulated the transcription of cdh and hdr. Besides, amino-utilizing bacteria was reduced under the high NZVI concentration, while low NZVI changed dominant genus with potential protein hydrolysis function from Candidatus Cloacamonas to Sedimentibacter. These results provide a guideline for proper NZVI utilization in wastewater treatment.

Asset Management in the Waste Treatment Environment

Abstract The main aim of the research study was to determine what drives the asset management inadequacy in the waste-water treatment utilities, as to ascertain the main drivers of the equipment failures are, and whether the maintenance strategies respond or are adequate to deal with the failure rate of equipment in the waste-water treatment utilities. The environmental impact driven from the non-compliant final effluent discharged into the water resources in the country resulted from the equipment failures in the plant. The maintenance strategies, asset policy, asset management plan, including the rehabilitation programme and all statutory regulation compliance are evaluated and analysed to ensure they are responding or aligned to the growing challenges faced by the waste-water treatment environment. Using the quantitative approach, the three groups; the asset management team, quality and process team and operations team of participants were to be selected. A convenient approved sampling method, the survey questionnaire was electronically shared to respond to the Covid-19 restriction and the structure telephonic interview so ascertain the level of understanding of the current asset management strategies, policies and procedures, the equipment failures impact to the utilities compliance and the further corporate risk and environmental impact from inadequately manages waste-water treatment utilities. The findings confirms that there is indeed lack of the synergies in the waste treatment environment emanating from a few aspects i.e., lack of due diligent in the application of maintenance strategies in the waste treatment works, lack of in-depth understanding of the impact from equipment failures in the waste treatment process, and the misalignment of the rehabilitation program, leading to gross environmental impact and corporate risk. It was further recommended the collaborations in the maintenance strategies development and review process. The rehabilitation programme should be aligned to the requirements of the process.

Resistome characterization of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli isolated from wastewater treatment utilities in Oregon.

Infections resistant to broad spectrum antibiotics due to the emergence of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae is of global concern. This study characterizes the resistome (i.e., entire ecology of resistance determinants) of 11 ESBL-producing Escherichia coli isolates collected from eight wastewater treatment utilities across Oregon. Whole genome sequencing was performed to identify the most abundant antibiotic resistance genes including ESBL-associated genes, virulence factors, as well as their sequence types. Moreover, the phenotypes of antibiotic resistance were characterized. ESBL-associated genes (i.e., blaCMY, blaCTX, blaSHV, blaTEM) were found in all but one of the isolates with five isolates carrying two of these genes (four with blaCTX and blaTEM; one with blaCMY and blaTEM). The ampC gene and virulence factors were present in all the E. coli isolates. Across all the isolates, 31 different antibiotic resistance genes were identified. Additionally, all E. coli isolates harbored phenotypic resistance to beta-lactams (penicillins and cephalosporins), while 8 of the 11 isolates carried multidrug resistance phenotypes (resistance to three or more classes of antibiotics). Findings highlight the risks associated with the presence of ESBL-producing E. coli isolates in wastewater systems that have the potential to enter the environment and may pose direct or indirect risks to human health.

Agro-wastes sustainable materials for wastewater treatment: Review of current scenario and approaches for India

Present study emphasis environmental concern of agro-waste materials and approaches for their sustainable utilization in wastewater treatment for environmental safety and waste management. This paper also addresses the environmental issues by identifying various categories of food waste, its consumption, amount of waste generated, and methods to reuse them properly. Discharge of Agro waste from agricultural and food processing industries leads to a problem of solid waste disposal and related environmental issues for this a lot of research has been conducted to use adsorbents as a treatment method for organic and inorganic pollutants. Utilizing agro-waste and bio-based material as adsorbents for removing contaminants from wastewater may be a sustainable option for environmental management and safety. Therefore, this paper highlights the performance of adsorbents based on agro-based materials (such as banana, citrus, apple, grape, and mango), vegetable waste (such as potato, tomato, etc.) for effective wastewater treatment, anddeveloping sustainable technology for environmental and health safety.

Fruit waste-derived cellulose and graphene-based aerogels: Plausible adsorption pathways for fast and efficient removal of organic dyes

A wide range of organic pollutants in industrial effluents, agricultural runoff, and domestic discharges are exacerbating water scarcity, leading to water-borne ailments, and adversely affecting the marine ecosystem and biodiversity. The efficient, sustainable, and cost-effective materials need to be addressed urgently for the removal of organic pollutants. Herein, ultra-light (0.018 g.cm−3) and highly porous (96.4%) composite aerogel is prepared by gelatinization of graphene oxide with fruit waste-derived cellulose. The macroscopic porosity generated by interconnecting cellulosic skeleton and graphene oxide sheets via hydrogen bonding network provided ample avenues for transport and diffusion of organic dyes-enriched wastewater throughout the cellulose-graphene oxide composite aerogel (CGA). Consequently, organic dyes are efficiently adsorbed by easily accessible surface sites distributed throughout the CGA. The size, charge, and chemical structure of organic dyes along with textural features and accessible surface active sites of CGA governed the adsorption process. The spectroscopic analyses based on FTIR, Raman, and XPS measurements suggest electrostatic, n-π, π-π, cation-π interactions, dipole–dipole hydrogen, and Yoshida hydrogen linkages as major interactive pathways for the adsorption of organic dyes by the CGA. Moreover, the composite aerogel furnished an excellent recyclability for the adsorptive removal of organic pollutants from wastewater. The present work promises the potential of 2D nanostructured layered materials and fruit-waste-derived composite aerogels for sustainable utilization in wastewater treatment, which can be an excellent step towards water security.

Pitfalls in international benchmarking of energy intensity across wastewater treatment utilities

The collection, treatment and disposal of wastewater is estimated to consume more than 2% of the world's electrical energy, whilst some wastewater treatment plants (WWTPs) can account for over 20% of electrical consumption within municipalities. To investigate areas to improve wastewater treatment, international benchmarking on energy (electrical) intensity was conducted with the indicator kWh/m3 and a quality control of secondary treatment or better for ≥95% of treated volume. The core sample included 321 companies from 31 countries, however, to analyse regional differences, 11 countries from an external sample made up of various studies of WWTPs was also used in places. The sample displayed a weak-negative size effect with energy intensity, although Kruskal-Wallace analyses showed there was a significant difference between the size of groups (p-value of 0.015), suggesting that as companies get larger; they consume less electricity per cubic metre of wastewater treated. This relationship was not completely linear, as mid to large companies (10,001–100,000 customers) had the largest average consumption of 0.99 kWh/m3. In the regional analysis, EU states had the largest average kWh/m3 with 1.18, which appeared a result of the higher wastewater effluent standards of the region. This was supported by Denmark being the second largest average consuming country (1.35 kWh/m3), since it has some of strictest effluent standards in the world. Along with energy intensity, the associated greenhouse gas (GHG) emissions were calculated enabling the targeting of regions for improvement in response to climate change. Poland had the highest carbon footprint (0.91 kgCO2e/m3) arising from an energy intensity of 0.89 kWh/m3; conversely, a clean electricity grid can affectively mitigate wastewater treatment inefficiencies, exemplified by Norway who emit just 0.013 kgCO2e per cubic meter treated, despite consuming 0.60 kWh/m3. Finally, limitations to available data and the analysis were highlighted from which, it is advised that influent vs. effluent and net energy, as opposed to gross, data be used in future analyses. The large international sample size, energy data with a quality control, GHG analysis, and specific benchmarking recommendations give this study a novelty which could be of use to water industry operators, benchmarking organisations, and regulators.

Implementation of cleaner production to improve wastewater treatment performance

Wastewater management in hospitals is needed to process wastewater generated from each hospital’s activities to reduce polluters’ burden in its disembodied. Wastewater management, in general in hospitals, applies the end of the pipe, which certainly does not completely solve existing environmental problems. The implementation of clean production is expected to improve wastewater treatment performance by identifying inefficiency opportunities in wastewater treatment and efforts to reuse processed water. The research was conducted by conducting laboratory analysis of wastewater treatment results using chemical and biological physics parameters and looking at the opportunities that can be done from the inefficient wastewater treatment described using flow diagrams. The analysis results showed that the processed wastewater from the wastewater treatment process still meets the standard requirements based on physical, chemical, and biological parameters so that it can be utilized back into raw water for hospitals. Identification of aspects found in the existence of inefficiencies is humans, methods, materials, and machinery. The application of cleaner production to provide recommendations for other hospitals to improve wastewater treatment performance as well as wastewater treatment utilization. Implementation of cleaner production to improve wastewater treatment performance through identification in each process and investigate the potential application of cleaner production that can be applied to the system..

Bio-adsorption of methylene blue dye using chitosan-extracted from Fenneropenaeus indicus shrimp shell waste

The cationic dye “Methylene blue” is widely used in textiles industry, pharmaceuticals, paper industries, and ink manufacturing etc, The washed off dyes discharged directly in water bodies and cause major damage to the environment. The molecule of dye is very stable, so that it is very difficult to decompose naturally. Therefore, it is essential to remove the dye by purifying, and prevent the environment from pollution. The –NH2 and -OH functional groups of Chitosan can induce the adsorbing capacity of dyes by its low surface area, porosity and high crystalline nature. Chitosan is an environment friendly, non-toxic, easily available, biodegradable, renewable biopolymer, and harmless to biota. Extraction of chitosan from the “Fenneropenaeus indicus” (Shrimp) shell and its utilization in wastewater treatment controls the environmental problems and contributes to solid waste management. In this study, the possible use of “Fenneropenaeus indicus” (Shrimp) shell chitosan for the bio-adsorption of MB dye was investigated by a batch adsorption method using different adsorbent doses with respect to experimental duration. The maximum amount of dye adsorption was obtained at a minimum dose of 4gram chitosan, with experimental time of 4 hours. The Fenneropenaeus indicus shell chitosan was found to be a better adsorbent since it removes about 93.23% of methylene blue dye from sample water. Further, characterization of functional groups was also done and the changes of groups were observed from both control and treated samples.

Enhancement of azo dyes removal efficiency by using LDH/Tris/Pd catalyst: Kinetic studies

LDH/Tris/Pd (CaAl‐layered double hydroxide/tris (hydroxymethyl)aminomethane/palladium) was synthesized and appraised for its catalytic activity towards the degradation of two selected azo dyes. The decolorization of azo dyes, acid red 18 (AR 18) and reactive yellow 15 (RY 15), requires considerably small amounts of synthesized catalyst. Kinetic studies show that the catalytic decolorization of these azo dyes follows the first order kinetic model. The reported method is simple and applicable; in addition, the stable catalyst can efficiently decolorize model azo dyes with good recyclability. Therefore, LDH/Tris/Pd can be accepted as the possible component for the utilization in wastewater treatment.

Advanced wastewater treatment stage for textile industry

Dissolved air flotation represents an important stage for wastewater treatment and was used during the last sixty years for different pollutants such as: suspended solids, greases, oils etc. Nowadays, the dissolved air systems are generally applied in industrial wastewater treatment plants, where the amount of pollutants is above the average (textile and leather industry). The research team members developed an innovative DAF unit and realized a laboratory demonstrator (figure 1). The laboratory installation was tested and the efficiency of wastewater treatment was demonstrated. The latest researches proved that flotation reagents have an essential role in the removal of different pollutants. The scientific literature demonstrates that these reagents can be used to remove the pollutants as sludge or foam, Reagents are divided into modifiers, flocculants, depressants, collectors and frothers, depending on their role the flotation process. Nanomaterial utilization in wastewater treatment has become an intensely studied topic. Collectors reagents, based on hydrophobic nanoparticles, can adsorb a larger quantity of pollutants due to the hydrophilic particle surfaces that facilitate the attachment of pollutants to air bubbles generated by the DAF unit. In the present paper, the researchers present that the role of nanoparticles is to facilitate particle-bubble attachment and/or to minimize detachment. The goal of the study is to consider the influence of nanoparticle parameters on the various stages of particle flotation to demonstrate the key role of nanoparticles in removal of pollutants from textile wastewaters.

Benefits of vitamin B5 regulation on CHO cells energy homeostasis and therapeutic production

Adsorption processes of 4GL on two different bentonite-based sorbents were compared: i) Sodium-bentonite in the presence of a cationic surfactant CTAMB; ii) organobentonite alone. This latter was prepared by exchanging the inorganic cation of bentonite with a quaternary ammonium cation at 100% of the clay's CEC. Batch adsorption studies were conducted to evaluate the effect of various parameters such as the quaternary ammonium cation (CTAMB) loading, contact time and initial 4GL concentration.From the kinetic study, it is interesting to note that Organobentonite exhibits faster kinetics compared to Na-bentonite/CTAMB system. The comparison between isotherm plots makes clear that the presence of CTAMB in solution changes the 4GL isotherm. Compared to organobentonite, the adsorption capacity is higher when CTAMB was present in solution. In this case, the results of 4GL adsorption by bentonite obey to Langmuir model. While for organobentonite, all models seem to be applicable. The difference between the two methods is confirmed by XRD analysis.The performance shown by Organobentonite and Na-bentonite/CTAMB system was suitable compared to other adsorbents, reflecting a promising future utilization in wastewater treatment.

Products from methanol by metabolic engineering of Bacillus methanolicus

Adsorption processes of 4GL on two different bentonite-based sorbents were compared: i) Sodium-bentonite in the presence of a cationic surfactant CTAMB; ii) organobentonite alone. This latter was prepared by exchanging the inorganic cation of bentonite with a quaternary ammonium cation at 100% of the clay's CEC. Batch adsorption studies were conducted to evaluate the effect of various parameters such as the quaternary ammonium cation (CTAMB) loading, contact time and initial 4GL concentration.From the kinetic study, it is interesting to note that Organobentonite exhibits faster kinetics compared to Na-bentonite/CTAMB system. The comparison between isotherm plots makes clear that the presence of CTAMB in solution changes the 4GL isotherm. Compared to organobentonite, the adsorption capacity is higher when CTAMB was present in solution. In this case, the results of 4GL adsorption by bentonite obey to Langmuir model. While for organobentonite, all models seem to be applicable. The difference between the two methods is confirmed by XRD analysis.The performance shown by Organobentonite and Na-bentonite/CTAMB system was suitable compared to other adsorbents, reflecting a promising future utilization in wastewater treatment.

Degradation of metronidazole antibiotic in aqueous medium using activated carbon as a persulfate activator

Abstract In this work, activation of persulfate (PS) and hydrogen peroxide (H2O2) in the presence of granular activated carbon (GAC) was studied in order to investigate the degradation of Metronidazole (MTZ) antibiotic in aqueous solution. The results showed that GAC could activate PS effectively better than H2O2. Also, both adsorption and oxidation process induced MTZ removal in the GAC/PS system with remarkable synergistic effect in the combined system. After 240 min, 50% of PS was degraded and 80% of MTZ and 65% of COD were removed under the ambient conditions containing initial MTZ concentration of 100 mg L−1, PS/MTZ molar ratio of 100/1, GAC dosage of 5 g L−1 and initial pH of 3.9. Both PS degradation and MTZ removal followed pseudo first order kinetic with rate constant of 0.0006 min−1 and 0.0023 min−1, respectively. Scavenging study using methanol and phenol as a radical scavenger showed that most oxidation of MTZ occurred on the surface or in the boundary layer around catalyst. It was also found that MTZ removal efficiency increased when PS concentration or GAC dosage increased. However, results showed that PS loading is more effective than GAC dosage. The MTZ removal efficiency was still considerable after 4 runs reusability of GAC which implied in-situ regeneration of catalyst. It can be concluded that GAC is a favorable and promising metal-free catalyst for wastewater treatment utilization.

A novel approach for removing an industrial dye 4GL by an Algerian Bentonite

Adsorption processes of 4GL on two different bentonite-based sorbents were compared: i) Sodium-bentonite in the presence of a cationic surfactant CTAMB; ii) organobentonite alone. This latter was prepared by exchanging the inorganic cation of bentonite with a quaternary ammonium cation at 100% of the clay's CEC. Batch adsorption studies were conducted to evaluate the effect of various parameters such as the quaternary ammonium cation (CTAMB) loading, contact time and initial 4GL concentration.From the kinetic study, it is interesting to note that Organobentonite exhibits faster kinetics compared to Na-bentonite/CTAMB system. The comparison between isotherm plots makes clear that the presence of CTAMB in solution changes the 4GL isotherm. Compared to organobentonite, the adsorption capacity is higher when CTAMB was present in solution. In this case, the results of 4GL adsorption by bentonite obey to Langmuir model. While for organobentonite, all models seem to be applicable. The difference between the two methods is confirmed by XRD analysis.The performance shown by Organobentonite and Na-bentonite/CTAMB system was suitable compared to other adsorbents, reflecting a promising future utilization in wastewater treatment.

Kinetic Sorption of 2,4-Dichlorophenol and Rhodamine-B from Aqueous Solutions onto Modified Phragmites Australis

This study investigates the potential use of activated carbon prepared from Phragmites Australis for the removal of 2,4-dichlorophenol (DCP) and Rhodamine-B (RB) from aqueous solutions. P. Australis activated carbon (PAAC), a new adsorbent, was prepared from P. Australis by H3PO4 activation. The sorption behavior and the rate-controlling sorption step has been discussed from the pseudo-first-order, pseudo-second-order, Elovich equation and intraparticle diffusion models. It was found that the adsorption of 2,4-DCP and RB onto PAAC both followed pseudo-second-order model. Adsorption mechanism studies revealed that the process followed both surface adsorption and particle diffusion. Accordingly, the activated carbon developed in this study is effective and practical for utilization in wastewater treatment for 2,4-DCP and RB removal.

Biochemical response of cyanobacterial species to trivalent chromium stress

Toxic metal reclamation from wastewaters using biotechnology has focused attention on a variety of microbes and one such potential group is Cyanobacteria. Effluent water discharged from tanneries support the growth of many microbial species including Cyanobacteria. In the present study an attempt has been made to study the growth response of six cyanobacterial species to trivalent chromium (Cr3+), before being used for phycoremediation. The studies relate to biochemical response of these species to different concentrations of Cr3+ under stress and their metal binding capacity in the media vis-à-vis its uptake in lab conditions. The results indicated that Aulosira sp. A287 exhibited high tolerance to Cr3+ (750mgL−1) in the media although the maximum uptake was observed in Spirulina platensis (214mgg−1). The biochemical analysis showed quantitative reduction in chlorophyll-a in S. platensis, Oscillatoria sp. A280 and Lyngbya sp. with increasing Cr3+ dosage, whereas the rest of the species showed decreasing trend. This change in protein profile was validated using SDS-PAGE. However, total carbohydrate increased in all the species tested when compared to controls. Among the species studied the response of S. platensis to Cr3+ stress was higher. The present study demonstrates the capability of cyanobacteria to withstand Cr3+ stress and their possible utilization in wastewater treatment.

Fate and behavior of extended-spectrum β-lactamase-producing genes in municipal sewage treatment plants

Extended-spectrum β-lactamases (ESBLs) have the capability of hydrolyzing a variety of the newer β-lactam antibiotics, including the third-generation cephalosporins and monobactams known as a rapidly evolving group of ESBLs. The purpose of this study was to investigate the occurrence and fate of β-lactamase producing genes (CTX-M type 1, type2, CTX-M probe for all groups except CTX-M-1, and TEM, SHV, OXA) through wastewater treatment utilities. β-lactamase producing genes in influent, digested sludge, activated sludge, and disinfected effluent were monitored. The results showed that influent contained high level of all target genes, and all CTX-M types, SHV, and OXA gene decreased significantly in biological treatment process such as activated sludge process and anaerobic digestion, however, TEM type was not effectively eliminated. Possibly, host microbes of TEM could be most resistant in target genes or to some extent gene transfer occurred in wastewater treatment processes. All target genes were significantly reduced during disinfection. Consequently, wastewater treatment process apparently reduced host microbes carrying β-lactamase producing genes effectively, although they are selectively removed in biological processes. In addition, the significant reduction during disinfection was shown, although slightly differences of removal efficiency were observed in resistance.