Wastewater Handling Research Articles

Readiness of Industrial Fisheries Wastewater Treatment at the Nusantara Fishing Port in Sibolga

The Nusantara Sibolga fishing port has a fish processing industry, which generates waste, including liquid waste, from its activities. The handling of wastewater from the industry involves treating the wastewater to meet quality standards before it is discharged into the open environment. In this study, the wastewater is channeled to the sea through an integrated wastewater treatment plant, as it originates from three different fishery industries. This is stipulated in the Minister of Environment Regulation Number 05 of 2014. The purpose of this study is to identify the facilities of the wastewater treatment installation and the final quality of its process. Data were obtained through direct surveys and interviews with stakeholders, and then samples for water quality were tested in a laboratory. The wastewater treatment installation equipment has the highest value from the readiness analysis results of the Sibolga fishing port wastewater treatment installation. The analysis showed that the highest score, 13 out of a total of 16, came from the collection tank of PT.ASL. The highest scores for treatment units were the sedimentation pond and the main collection tank, both scoring 11. This evaluation is also related to the quality results of the wastewater at the outlet. The evaluation of the readiness analysis results involves improving each device of the wastewater treatment installation for optimal results.

PVDF‐Based Electrospun Nanofibers for Oil/Water Separation: A Review

AbstractThe rising widespread oil‐impacted wastewater warrants an urgent call for innovative approaches to the handling of oily wastewater. A variety of techniques has been investigated to treat oil‐impacted water, and they are found to be inefficient. Electrospun nanofibers emerge as the viable technique to treat oily wastewater precisely owing to their high specific surface areas and interconnected nanoscale pore structures. In this review, a brief background on the study is provided followed by the environmental pollution by the oily wastewater. Subsequent to that, the polyvinylidene fluoride (PVDF) modification methods are also presented followed by the physicochemical properties of both the electrospun PVDF blends and the PVDF‐based composites. Furthermore, the performances of the PVDF‐based composites in oil/water separation are described. It is concluded with the future prospects for using PVDF‐based composites for oil/water separation.

Temperature Dependence Study of Water Dynamics in Fluorohectorite Clays Using Molecular Dynamics Simulations

We have carried out molecular dynamics (MD) simulation techniques to study the diffusion coefficient of interlayer molecules at different temperature. We have focused on the translation dynamics of water in bihydrated states within the context of water dynamics in clays. We concentrated on temperatures between 293 and 350 K, i.e., the range important to daily life wastewater handling. A natural clay has been modified as a synthetic clay called fluorohectorite clay, and the properties are studied using MD simulations, the result of which allows us to understand the determining parameters through a comparison with experiment values. The activation energyEais determined by our simulation to be between [0.09−0.17] eV per particle. The calculated diffusion constants are in the order of 10−5 cm2s−1. The simulation results are in a good agreement with experiments for the relevant set of conditions, and give insight into the origin of the observed dynamics.

Impact of heat-treatment on wastewater analytical parameters

Abstract Raw wastewater analysis is an important step in treatment assessment; however, it is associated with risks of personnel exposure to pathogens. Such risks are enhanced during virus outbreaks, such as the COVID pandemic, and heat-treatment is a commonly used mitigation measure. We examined whether heat-treatment compromises wastewater analytical parameters results. We found that heat-treatment of blackwater at 60 °C for 90 min in capped containers yielded no statistically different values (p > 0.05) for pH, chemical oxygen demand (COD), ammonia (NH3), total nitrogen (TN), total suspended solids (TSS), and turbidity for specimens from three different sources. This heat-treatment inactivated coliform bacteria (>4 log10 reduction) thus compromising the measurement of commonly used fecal contamination indicators. The observation of intact helminth eggs in heat-treated specimens suggests that the helminth egg enumeration assay is not compromised. These findings indicate that heat-treatment for the safe handling of wastewater, as may be needed in future virus outbreaks, does not affect the measurements of many common wastewater physico-chemical properties.

Engineered multi-walled carbon nanotubes for disinfecting wastewater

Discharging a considerable amount of untreated effluent directly into a water body significantly impacts water quality. Contaminated water can spread waterborne infections, resulting in exponentially high death rates worldwide. Although carbon nanotubes are frequently employed in industry, little is understood about how they may affect aquatic microbial ecosystems. Therefore, the present investigation aimed to exploit multi-walled carbon nanotubes (MWCNTs) as a potential disinfectant to eliminate waterborne bacteria during wastewater treatment. The current study utilized six different microbial strains, including Escherichia coli O157, Salmonella enterica, Staphylococcus aureus, Enterococcus faecalis, Risopus oryzae, and Rhizomucor miehei, to examine the antimicrobial properties of MWCNTs. The physical and morphological properties of MWCNTs were characterized using transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Dynamic light scattering (DLS), and zeta potential. The FTIR spectra of MWCNTs have appeared at 11,029 cm−1, and the zeta potential and particle size recorded at −28.89 mV and 425 nm, respectively. On the other hand, the results indicated that the width of the inhibition zone varied between 11 and 29 mm for E. coli O157, 11–31 mm for S. enterica, 16–37 mm for S. aureus, 14–34 mm for E.faecalis, 10–26 mm for R. oryzae, and 10–24 mm for Rh. miehei. The reduction rate of disinfection was estimated. The effective dose of MWCNTs (4xMIC) in a disinfection experiment could all selectedpathogens after 125 min exposure time. This study provided an overview of the antimicrobial properties of MWCNTs, their multiple modes of action against pathogens, and their usefulness in wastewater disinfection and microbial control. Thus, this current research work can also recommend MWCNTs as a good solution and beneficial disinfecting agent for inactivating waterborne pathogens within wastewater handling.

Feasibility study of applying a graphene oxide-alginate composite hydrogel to electrokinetic remediation of Cu(II)-contaminated loess as electrodes

Inappropriate handling of heavy metal-containing wastewater resulting from extensive mining and smelting activities causes serious threats to surrounding environments and human health. The electrokinetic (EK) technology has been extensively applied to remediate heavy metal-contaminated sites because of its great manoeuvrability. The electrochemical polarization effect, however, reduces the electron transfer rate and could badly degrade EK removal efficiency. To this end, the present work proposed a novel graphene oxide-alginate composite hydrogel and applied it to copper removal as electrodes in EK remediation. A series of laboratory tests concerning its physical, mechanical, adsorption, and electrochemical properties were conducted. The graphene oxide (GO) particles provide larger average pore size and pore volume than traditional activated carbon electrodes. The surface functional groups, including hydroxyl, carboxyl, and epoxide groups, promote hydrogen bond formation. The GO particles and the calcium alginate are crosslinked with the hydrogen bonds, improving the mechanical properties of the graphene oxide-alginate composite hydrogel. Furthermore, the functional groups also encourage copper adsorption, and a high GO proportion does not necessarily mean an improvement in copper adsorption. The dynamic mechanism of Cu(II) adsorption onto the graphene oxide-alginate composite hydrogel conforms with the pseudo-second-order kinetic model. Moreover, the absence of oxidative and reductive peaks in the cyclic voltammograms is mainly attributed to the non-faradaic nature of the graphene oxide-alginate composite hydrogel, indicating a reduced electrode polarization effect. The Nyquist plot also approves its low resistance nature. The results were then compared against other electrodes to highlight the relative merits of the proposed graphene oxide-alginate composite hydrogel electrode.

Potential Exposure to Respiratory and Enteric Bacterial Pathogens among Wastewater Treatment Plant Workers, South Africa

Wastewater handling has been associated with an increased risk of developing adverse health effects, including respiratory and gastrointestinal illnesses. However, there is a paucity of information in the literature, and occupational health risks are not well quantified. Grab influent samples were analysed using Illumina Miseq 16S amplicon sequencing to assess potential worker exposure to bacterial pathogens occurring in five municipal wastewater treatment plants (WWTPs). The most predominant phyla were Bacteroidota, Campilobacterota, Proteobacteria, Firmicutes, and Desulfobacterota, accounting for 85.4% of the total bacterial community. Taxonomic analysis showed a relatively low diversity of bacterial composition of the predominant genera across all WWTPs, indicating a high degree of bacterial community stability in the influent source. Pathogenic bacterial genera of human health concern included Mycobacterium, Coxiella, Escherichia/Shigella, Arcobacter, Acinetobacter, Streptococcus, Treponema, and Aeromonas. Furthermore, WHO-listed inherently resistant opportunistic bacterial genera were identified. These results suggest that WWTP workers may be occupationally exposed to several bacterial genera classified as hazardous biological agents for humans. Therefore, there is a need for comprehensive risk assessments to ascertain the actual risks and health outcomes among WWTP workers and inform effective intervention strategies to reduce worker exposure.

Co-utilization of aqueous carbonated basic oxygen furnace slag (BOFS) and carbonated filtrate in cement pastes considering reaction duration effect

It is generally agreed that aqueous carbonation of basic oxygen furnace slag (BOFS) is a promising and effective strategy to sequestrate CO2 and enhance the slag properties for use as a construction material. However, the handling of wastewater produced in the aqueous carbonation route is still a challenge. This work investigates the impact of co-utilizing carbonated BOFS as a partial cement replacement and carbonated filtrate as a mixing solution on the fresh and mechanical properties as well as the hydration and microstructural characteristics of cement paste. The carbonation duration of BOFS via the aqueous route (0, 10, 20, 30, 40, 80, and 120 min) was studied, and it was found that calcite was the dominant CaCO3 polymorph with different crystal shapes depending on the concentration of Mg ion in the slurry solution. The early-age compressive strength of blended cement pastes improved with the addition of 15% BOFS slurry carbonated for 40 min compared to as-received BOFS since the in-situ produced fine CaCO3 particles in the former could promote nucleation sites for cement hydration. However, the strength of pastes containing BOFS slurry carbonated for a longer duration was decreased due to the inhibited hydration reaction induced by the nesquehonite (MgCO3∙3H2O). At later ages of hydration, the nucleation effect was less obvious and the strength of cement paste was limited by the lower cement content. Moreover, the volume expansion issue caused commonly by f-CaO/MgO in BOFS can be improved through the precipitation of CaCO3 and nesquehonite.

Construction of novel g-C3N4 coupled efficient Bi2O3 nanoparticles for improved Z-scheme photocatalytic removal of environmental wastewater contaminant: Insight mechanism

Recently, the major environmental pollution produced by the release of wastewater in liquid type is one of the most extensive forms of foremost pollution in water ecosystems. In this article, the Bi2O3/g-C3N4 nanocomposite with a direct Z-scheme was effectively obtained by a facile hydrothermal system. The crystal structures, surface morphology, chemical composition, and the optical belongings of the as-obtained composite catalysts were examined by Power XRD, FT-IR spectra, High-resolution XPS spectra, FE-SEM images with EDX spectra, High-resolution TEM images, UV–Vis DRS, and PL spectra respectively. Furthermore, the photocatalytic performance was assessed by the degradation of aqueous Rhodamine B (Rh B) dye under visible-light exposure. The Bi2O3/g-C3N4 composite photocatalysts (PCs) showed the maximum photo-degradation efficiency through a rate constant value of 0.0149 min−1, which is 4.9 and 5.3 folds superior to Bi2O3, and GCN, respectively. The better GBO2 nanocomposite PCs showed a superior photocatalytic degradation performance (>82%) of aqueous Rh B dye after five successive recycles. Moreover, based on these outcomes of the radical scavenging test, a direct and effective Z-scheme photocatalytic charger transfer mechanism was also projected. Finally, the reusability of the as-obtained Bi2O3/g-C3N4 nanocomposite has better stability and reusability, which was a favourable applicant for wastewater handling.

A comparative life cycle assessment (LCA) analysis of innovative methods employing cutting-edge technology to improve sludge reduction directly in wastewater handling units

Sludge reduction technologies can be used as an alternative plan to dispose of excess sludge in wastewater treatment plants, but the sustainability of these strategies is a challenging task. In this study, the potential environmental implications of innovative technologies based on lab-scale results published in the literature were assessed from the life cycle assessment (LCA) view point. Accordingly, three different scenarios using various sludge reduction mechanisms were selected and analyzed. The scenarios include (1) an integrated oxic-setting-anaerobic and ultrasound process; (2) a sequencing batch reactor (SBR) with an anaerobic side-stream reactor to its return activated sludge line; and (3) the anaerobic-anoxic-oxic system in conjunction with an ozone reactor. LCA was conducted through the CML-IA (baseline 2000) method. A sensitivity analysis was also done in order to determine how changes in the inputs are affecting the overall sustainability of the system. The environmental impact evaluation of three scenarios indicated that the integrated SBR with an anaerobic side-stream reactor was the most efficient and sustainable alternative in environmental terms. Although the upgraded SBR system was not the best alternative in terms of sludge reduction (65 % versus 78 % for Scenario 1 and 70 % for Scenario 3), it showed the highest overall performance and also demonstrated the lowest environmental impact compared to other scenarios. Because the scenarios studied were cutting-edge and provided novel sludge reduction strategies based on lab-scale results published in the literature, a comprehensive economic analysis and scale-up considerations are recommended to effectively assist decision-makers in guiding the development of emerging technologies.

Removal of methylene blue from aqueous solution using a thiol-functionalized ionic liquid-based periodic mesoporous organosilica: Kinetic and thermodynamic studies

Integrated wastewater handling and organic dye management are important challenges that scientists are working to solve today. A thiol-functionalized ionic liquid-based periodic mesoporous organosilica (PMO-IL-SH) has been prepared and characterized using diffuse reflectance infrared Fourier transform, scanning electron microscopy, transmission electron microscopy and thermal gravimetric analysis and applied as a robust adsorbent for removal of methylene blue (MB) as an organic dye from an aqueous solution. The optimized conditions were achieved by using 0.04 g of PMO-IL-SH, 10 mg L−1 of MB at 35 min of contact time and pH 8. Fitting the equilibrium data shows the suitability of the Langmuir model with a second-order equation to control the kinetics of the adsorption process with the adsorption capacity of 384.61 mg g–1. This study may provide insight for remarkable removal of organic dyes to refine water challenges.

Current Trends in the Utilization of Photolysis and Photocatalysis Treatment Processes for the Remediation of Dye Wastewater: A Short Review

Development in the textile industry leads to an increased demand for the use of various dyes. Moreover, there is the use of some dyes in the food industry as well as medical diagnostics. Thereby, increased demand for dyes in various fields has resulted in dye-containing wastewater. Only a small portion of the generated wastewater is adequately treated. The rest is usually dumped or otherwise directly discharged into the sewage system, which ultimately enters rivers, lakes, and streams. The handling and disposal of such concentrated wastewater, especially the dye-containing wastewater, is considered to be a major environmental issue from the moment of its generation to its ultimate disposal. Conventional water treatment methods such as flotation, filtration, adsorption, etc., are non-destructive physical separation processes. They only transfer the pollutants to other phases, thereby generating concentrated deposits. The advanced oxidation process (AOP) is one of the most effective emerging methods for the treatment of wastewater containing chemical pollutants. The method involves the formation and interaction of highly reactive hydroxyl radicals under suitable activation conditions. These radicals are non-selective and efficient for the destruction and eventual mineralization of recalcitrant organic pollutants. This review aims at the pros and cons of using photocatalysis as an efficient AOP to degrade dye-containing wastewater.

Abattoir Wastewater Treatment Plants in India: Understanding and Performance Evaluation

Slaughterhouse plants, especially meat and poultry products (MPPs), generate significant quantities of wastewater during the slaughtering process and the cleaning of machinery. The handling and final disposal of wastewater from the slaughterhouse is a public and environmental health issue due to its pollution potential. The monitoring of three full-scale buffalo meat-based abattoir effluent treatment plants (ETPs) to remove organic matter and nutrients was conducted at three separate sites in India. Rotary and static screens, an equalization tank, a dissolved air flotation (DAF) system, aeration tanks, and clarifiers were the component unit operations/processes of the wastewater treatment systems. All the treatment plants were operating at an average flow rate of 254 m3/d Meem Agro (designed capacity 500 m3/d); 427 m3/d Al Noor (designed capacity 500 m3/d), and 353 m3/d International Agro Foods (IAF) plant (designed capacity 750 m3/d) for the treatment of slaughterhouse wastewater. The Al Noor and Meem Agro’s ETP consisted of a DAF unit working at the surface-loading rates of 5.7 and 1.48 m3/m2 h, respectively, applied during the analysis to the DAF system, resulting in 46.5 and 56.8% efficiencies of O&G and SS removal. The ETP of Al Noor and Meem Agro and IAF was loaded at an organic loading rate of 276 kg COD/day, 746 kg COD/day, and 629 kg COD/day, respectively. Performance of ETPs showed that the efficiency of total COD, total BOD, and TSS removal was 97, 98, and 99%; 94, 94, and 93%, and 95, 98, and 99% for Al Noor, Meem Agro, and IAF plants, respectively. The treatment plants’ efficiencies in all three plants for the removal of organic matter surpassed the effluent discharge level (as per Indian standards). Still, it is concluded that the ETPs need to be upgraded by incorporating the advanced wastewater treatment methods for the removal of nutrient concentration from treated effluents.

Comparison of sono-direct and sono-alternate current electro-coagulation processes for removal of color and turbidity from domestic wastewater

Background: Nowadays there is a problem related to wastewater handling which is released from different activities. Electrocoagulation has been a dominant treatment method for wastewater treatment. There are different forms of electrocoagulation methods for wastewater treatment. Nevertheless, there was no comparison made for the removal efficiency of the sono-alternate current (SAC), alternate current (AC), sono-direct current (SDC), and direct current (DC) electrocoagulation process. Methods: The efficiency of electrocoagulation method was compared for removal of color and turbidity from Jimma University domestic wastewater. Batch reactor DC/AC electrocoagulation cell was used to determine the removal efficiency. During the comparison, the response surface methodology (RSM) was used to analyze and optimize the data taken from the laboratory. In addition, ANOVA was used to analyze the interaction effects of different parameters. Results: The removal of color and turbidity from domestic wastewater was about 97.53% and 95.28% respectively, using direct current electrocoagulation (DCE). For alternate current electrocoagulation (ACE), the removal of color and turbidity was 98.35% and 96.12%, respectively. The removal of color and turbidity for sono-DCE (SDCE) was obtained to be 98.55% and 98.27%, respectively and for sono-ACE (SACE), the removal of color and turbidity was 99.95% and 99.76%, respectively at the optimum experimental conditions of chemical oxygen demand (COD) 960 g/L, initial wastewater pH of 6.8, the current density of 0.4 A/dm2 , inter-terminal spacing of 1 cm, and the association of electrode of Al-Al. Conclusion: According to the findings of this study, it can be concluded that, the SAC electrocoagulation method is the best and promising technique compared with all other electrocoagulation methods.

Comparison Study on Sonodirect and Sonoalternate Current Electrocoagulation Process for Domestic Wastewater Treatment.

Nowadays, there is a problem related to wastewater handling which is released from different activities. The electrocoagulation method has been a dominant treatment method for wastewater treatment. There are different forms of electrocoagulation methods for wastewater treatment. Nevertheless, there was no comparison made for the removal efficiency of the sonoalternate current (SAC), alternate current (AC), sonodirect current (SDC), and direct current (DC) electrocoagulation process. The efficiency of electrocoagulation methods was compared for their removal of chemical oxygen demand (COD) from Jimma University domestic wastewater. Batch Reactor DC/AC electrocoagulation cell was used to determine the removal efficiency. During the comparison, the response surface methodology (RSM) was used to analyze and optimize the data taken from the laboratory. Besides, ANOVA was used to analyze the interaction effects of different parameters. The removal of COD from domestic wastewater was achieved with DCE, ACE, SDCE, and SACE which were 82.6%, 86.58%, 88.6%, and 92.5%, respectively, under optimal experimental conditions. From the finding, SACE was more successful at removing % COD than the DCE, ACE, and SDCE methods. For DCE and SDCE, the formation of an impermeable oxide layer at the cathode and the occurrence of corrosion at the anode due to oxidation made the COD removal process less efficient compared with SACE processes. From the experimental results it can be concluded that the SACE has the lowest power consumption and higher process efficiency than the other EC methods and can be a promising solution for removing pollutants from domestic wastewater.

Philippine Urban Infrastructure: Looking Back and Looking Forward

Infrastructure consists of transportation, communications, water supply, wastewater treatment and disposal, drainage, solid wastes management, and energy. This short review focuses on urban infrastructure, its state, issues, and challenges in the megacities of the Philippines, namely, Metro Manila, Metro Cebu, and Metro Davao. In terms of transportation, the major cities have been experiencing worsening transport and traffic problems resulting in high rates of traffic accidents and air pollution. In communications, although the liberalization policy of communications allowed more players that provide all types of communication services, the country’s communication, suffers from low internet speed, high infrastructure cost, outdated law, unsatisfactory service, and hackers. Problems for water supply include lack of water supply, high rates of non-revenue water, and increasing demand due to population growth and requirements of agriculture, business, and industrial establishments. Water-related problems are handling of wastewater, drainage, and flooding. On the other hand, solid wastes volume increases with increasing population and industrialization. Strategies to address the problems and challenges caused by rapid urbanization include institutional reforms to create multiple growth centers, improve public transport system and services so that many more people will use it, address the widening water supply/demand gap through water conservation, watershed management, rainwater harnessing, and expansion of the water supply system. To address the widening water supply/demand gap, water conservation, watershed management, rainwater harnessing, and expansion of the water supply system need to be careful, encompassing plan of action and implementation. Communications problems require expanding market liberalization, evaluating policy structures, review of licensing schemes among others. For solid waste management, the government‘s overall policy is shown in the National Solid Waste Management (NSWM) Framework with the key words: avoid, reduce, reuse, recycle, recover, treatment, and residues management.

Use of Reactivated Spent FCC Catalyst as Adsorbent for Lead (II) Ions from Refinery-based Simulated Wastewater

Improper handling of wastewater from various industries causes environmental pollution. Hence, this study involved using a reactivated spent FCC catalyst, a cheap and reliable adsorbent for Pb2+ removal from refinery-based simulated wastewater. In contrast, response surface methodology (RSM) was used to determine the optimum operating condition. The adsorptive capacity of the reactivated spent FCC catalyst was observed using different parameters such as temperature, pH, adsorbent dosage, and contact time. At the end of the study, it was found that the optimum condition for removing Pb2+ was at pH of 7, adsorbent dose of 1.75 g, contact time of 75 mins, and temperature of 117 oC. At this condition, the maximum removal efficiency of Pb2+ was found to be 100 %. A quadratic model equation via central composite design under the RSM was developed to predict the Pb2+ removal from all the input parameters. Based on the F-statistic values, the temperature had the greatest influence on the removal of Pb2+ while adsorbent dosage and contact time were also significant.

Machine Learning Modeling of Water Use Patterns in Small Disadvantaged Communities

Water use patterns were explored for three small communities that are located in proximity to agricultural fields and rely on their local wells for potable water supply. High-resolution water use data, collected over a four-year period, revealed significant temporal variability. Monthly, daily, and hourly water use patterns were well described by autoregressive moving average (ARMA) models. Model development was supported by unsupervised clustering analysis via self-organizing maps (SOMs) that revealed similarities of water use patterns and confirmed the time-series water use model attributes. The inclusion of ambient temperature and rainfall as model attributes improved ARMA model performance for daily and hourly water use from R2 ~0.86–0.87 to 0.94–0.97 and from R2 ~0.85–0.89 to 0.92–0.98, respectively. Water use predictions for an entire year forward in time was feasible demonstrating ARMA models’ performance of (i) R2 ~0.90–0.94 and average absolute relative error (AARE) of ~2.9–4.9% for daily water use, and (ii) R2 ~0.81–0.95 and AARE ~1.9–3.8% for hourly water use. The study suggests that ARMA modeling should be useful for analysis of temporally variable water use in support of water source management, as well as assessing capacity building for small water systems including water treatment needs and wastewater handling.

Stress-induced activation of the commercial Fe-based metallic glass ribbons for azo dye degradation

Handling of massive azo dye wastewater and waste commercial Fe-based metallic glass ribbons for iron core uses separately is lavish. A win-win trade would be degrading the azo dye by the Fe-based metallic glass ribbons. However, the waste ribbons, especially those undergone heat treatments, generally show insufficient degrading activity. In this work, a general stress-induced activation strategy is proposed to improve the azo dye degradation performance of the Fe-based metallic glass ribbons via the facile and efficient rolling treatment, which is generally applicable for various alloy systems of as-cast and as-heated states. A set of in-situ degradation vs. stress experiment confirms the stress-induced activation behavior. The stress introduced by rolling treatment is responsible for the decreased activation energy that leads to increased reductivity, which results in facilitated degradation activity and diffusion-controlled mechanism. This work is of great economic and environmental importance for handling the azo dye wastewater with the massive waste Fe-based metallic glass ribbons.

Straightforward Synthesis of Mn3O4/ZnO/Eu2O3-Based Ternary Heterostructure Nano-Photocatalyst and Its Application for the Photodegradation of Methyl Orange and Methylene Blue Dyes.

Zinc oxide-ternary heterostructure Mn3O4/ZnO/Eu2O3 nanocomposites were successfully prepared via waste curd as fuel by a facile one-pot combustion procedure. The fabricated heterostructures were characterized utilizing XRD, UV–Visible, FT-IR, FE-SEM, HRTEM and EDX analysis. The photocatalytic degradation efficacy of the synthesized ternary nanocomposite was evaluated utilizing model organic pollutants of methylene blue (MB) and methyl orange (MO) in water as examples of cationic dyes and anionic dyes, respectively, under natural solar irradiation. The effect of various experimental factors, viz. the effect of a light source, catalyst dosage, irradiation time, pH of dye solution and dye concentration on the photodegradation activity, was systematically studied. The ternary Mn3O4/ZnO/Eu2O3 photocatalyst exhibited excellent MB and MO degradation activity of 98% and 96%, respectively, at 150 min under natural sunlight irradiation. Experiments further conclude that the fabricated nanocomposite exhibits pH-dependent photocatalytic efficacy, and for best results, concentrations of dye and catalysts have to be maintained in a specific range. The prepared photocatalysts are exemplary and could be employed for wastewater handling and several ecological applications.