Total Organic Carbon Removal Efficiency Research Articles

Optimizing organic pollutant removal from hydrazine hydrate waste brine through thermal activation of sodium persulfate assisted by response surface methodology

Addressing the environmental impact of toxic waste from hydrazine manufacturing is crucial due to its severe implications for ecosystem health. This study focused on optimizing the removal of organic pollutants from hydrazine hydrate waste brine. By utilizing thermally activated sodium persulfate (Na2S2O8), a mathematical model was developed that links operational variables—temperature, Na2S2O8 concentration, pH, and reaction time—with the efficiency of total organic carbon (TOC) removal. The application of response surface methodology (RSM) incorporating the Box-Behnken Design (BBD) facilitated the identification of optimal conditions: Na2S2O8 concentration of 4.22 g·L−1, pH of 9.8, temperature of 90.0 °C, and reaction time of 180 min. These conditions achieved a TOC removal efficiency of 86.6 %, closely matching the actual experimental efficiency of 87.3 %. This study not only validates the effectiveness of RSM in refining the Na2S2O8 treatment process but also underscores the efficiency of thermally activated Na2S2O8 in purifying water from organic pollutants. The findings offer valuable insights into environmental management and endorse the sustainable development of waste treatment technologies.

Bioremediation of dissolved organic compounds in produced water from oil and gas operations using Chlorella sorokiniana: a sustainable approach.

The sustainable treatment of petroleum-derived produced water (PW), a significant byproduct of oil and gas extraction, presents a persistent problem due to the presence of organic pollutants. This study examines the potential of the microalga Chlorella sorokiniana (C. sorokiniana) for the bioremediation of dissolved organic pollutants in PW. The primary objectives were to evaluate the efficacy of C. sorokiniana in decreasing the levels of dissolved organic contaminants while examining its growth and survival in such a complex environment. The cultivation of C. sorokiniana in photobioreactors containing synthetic produced water (SPW), supplemented with synthetic municipal wastewater (SMW) to provide essential nutrients, was carried out under controlled laboratory conditions. Parameters such as biomass growth, lipid content, and the microalgae's capacity to metabolize organic compounds are monitored over time. The results indicate that, except for 100% PW, maximum biomass output after 16 days ranged from 733 to 1077 mg/L. Total organic carbon (TOC) removal efficiency increased with rising PW concentrations, peaking at 85% for 50% PW. The cultivation period resulted in substantial nitrogen and phosphorus removal from the enriched PW media, achieving a maximum nitrogen removal of 87% at 10% PW and a phosphorus removal of 98.5% at 40% PW. Lipid content ranged from 12 to 16% during this period. In conclusion, C. sorokiniana offers a promising and sustainable approach for the bioremediation of dissolvedorganic compounds in PW. This method provides an eco-friendly option to reduce the ecological impact associated with petroleum-derived PW.

Degradation of the Antibiotic Sulfamethoxazole by Ozonation: A Comprehensive Review

ABSTRACTSulfamethoxazole (SMX) is an antibiotic widely used for the treatment of several diseases, especially respiratory and urinary. Due to its widespread use, its presence in the environment has been on the rise. This study discusses the degradation of the antibiotic SMX through the ozonation process. SMX is preferentially degraded by the direct action of O3 on the molecule, starting by breaking the double bonds in the aromatic ring. Through ozonation it is possible to obtain complete SMX degradation within 10 min, but the mineralization of the solution is not achieved, reaching total organic carbon removal efficiencies of 5%–60%, depending on the reaction time. Factors such as the presence of organic matter (OM) and the pH of the solution interfere with the degradation of SMX. The OM acts as a radical scavenger, decreasing the efficiency of degradation, while the pH interferes with the decomposition of O3 into radicals and the dissolution of the oxidant in the medium, in addition to influencing the state of ionization of the SMX making it more or less prone to reactions. In general, most other remediation processes are carried out on a laboratory scale. To increase the level of these processes to a full scale, more pilot‐scale studies are needed. In addition, it is necessary to focus on the practice of reusing materials, avoiding the generation of secondary pollution, and increasing the useful life of the material. The review also discusses the reaction mechanisms, intermediate compounds formed, mineralization of the solution, and factors that influence the process, which can help in making decisions for future studies to be carried out in the area. Prospects in the research area revolve around using metal–organic frameworks as molecular imprinting technology to modify heterogeneous catalysts, integration of external energy, bimetallic systems, and evaluation of deactivation mechanisms.

Carbon defect induced electron transfer promotes electrocatalytic activation of molecular oxygen to selectively generate singlet oxygen for pollutants removal

This study explored the design of heterojunctions incorporating defective graphene and boron nitride (BN) to activate molecular oxygen (O₂) and degrade sulfamethoxazole (SMX) by establishing efficient electron transport channels. These heterojunction catalysts, designed using theoretical predictions, were synthesized by controlling carbon defect concentration and pyrolysis temperature. The optimized GBN cathode achieved a maximum SMX degradation rate of 0.0252 min⁻¹, with a total organic carbon (TOC) removal efficiency of 47.31 %. Singlet oxygen (¹O₂) was identified as the primary reactive oxygen species, exhibiting a generation rate of 18.66 μM min⁻¹ and contributing 93.5 % to SMX degradation. Results demonstrated that an optimal defect concentration enhances electron transfer, promoting the 2-electron reduction of O₂ to H₂O₂ and facilitating further H₂O₂ activation, thereby accelerating SMX degradation. This work advances the development of non-metallic cathodic catalysts and provides valuable insights into electrochemical degradation mechanisms for organic pollutants.

Enhanced Organics Removal Using 3D/GAC/O3 for N-Containing Organic Pharmaceutical Wastewater: Accounting for Improved Biodegradability and Optimization of Operating Parameters by Response Surface Methodology

Pharmaceutical industry effluents often contain high concentrations of refractory organic solvents, chemical oxygen demand (COD), and total dissolved solids (TDSs). These wastewaters, including N-containing organic solvents known for their persistence and toxicity, pose significant environmental challenges. The study evaluated the efficacy of 3D/Granular Activated Carbon (GAC)/O3 treatment compared to linear process additions when treating real pharmaceutical wastewater, and revealed a 2.73-fold enhancement in COD mineralization. The process primarily involves the direct oxidation of monoprotic organic acids found in real pharmaceutical effluents, such as acetic and formic acid, crucially influencing mineralization rates. Optimal conditions determined via the response surface methodology were 125 g/L GAC, 30 mA/cm2, and 75 mg/L O3, achieving high total organic carbon (TOC) and COD removal efficiencies of 87.19 ± 0.19% and 89.67 ± 0.32%, respectively (R2 > 0.9), during verification runs. Current density emerged as the key parameter for organic abatement, aligning with the emphasis on direct oxidation at the anode surface. This integrated approach enhances biodegradability (BOD5/COD) and reduces acute toxicity associated with persistent N-containing solvents, demonstrating promising applications in pharmaceutical wastewater treatment.

Fabrication cellulose/epoxy sponge via surface embedding for efficient and continuously oil/water separation

Discharging oily waste into environment have caused sever water, soil and air pollution. Mechanical compressible polymeric sponges show great potential in oil/water separation through adsorbing/filtering. However, most of these developed sponges were intermittent/manually in oil/water separation and the fabrication always complex. Herein, we developed superwetting sponge by embedding a handful amount of cellulose at the surface of sponge skeleton and delivered excellent mechanical elasticity and robustness. The cellulose/epoxy sponge (embedding 0.33 w% cellulose) can be compressed to 60 % strain with 60 kPa stress and returned to its original shape after 50 times cyclic strain-stress tests. Increasing the embedding amount generated adverse effects on mechanical elasticity and porosity. The as-fabricated cellulose/epoxy sponge showed high separation efficiency (94–99 %) on various oil/water mixtures and showed stable cyclic separation efficiency (>94 %). The optimized cellulose/epoxy sponge was placed into designed separator to separate dispersed oils showing satisfactory total organic carbon removal efficiency (56.63 %) and the inject flow rate showed adverse effects on separation efficiency. Surface embedding is feasible for fabrication mechanical elastic and robust superwetting sponge. The sponge separator showed high separation efficiency of dispersed oil indicating the great of potential polymeric sponge in practical application.

Efficient desalination and synergistic toxic organics removal in RO concentrates with electrochemical advanced oxidation processes

A novel Ce-doped Ti4O7 (Ti/Ti4O7-Ce) electrode was fabricated and investigated in treatment of reverse osmosis (RO) concentrates with Electrochemical advanced oxidation processes (EAOPs). Characterization results showed that Ce was successfully incorporated into the Ti4O7, leading to an increase on the hydroxyl radical (•OH) generation and electrochemical stability compared with Ti/Ti4O7. Ti/Ti4O7-Ce electrodes achieved efficient desalination and oxidation of toxic organics, which was mainly attributed to the indirect oxidation induced by electro-generated •OH and change of electrochemical properties. The action of electric field had great effect on desalination process, and the anions in reverse osmosis concentrates (ROC) deposited on the cathode through this action by characterization and analysis. In the treatment, about 10.8–11.2 % of desalination efficiencies can be obtained, and the removal efficiency of toxic organics enhanced with the increase of Ce addition and current density. In the experiments, TOC removal efficiencies were 57 %, 66 % and 69 % under 10, 20 and 30 mA/cm2 in the 180 min treatment. Toxic chemicals, such as alkanes, haloalkanes, etc., were the main components in treatment, and the organic pollutants with medium molecular weight (MMW) (1400 g/mol) and low molecular weight (LMW) (40–230 g/mol) in ROC were removed. Although slight decreased durability was observed due to Ce leaching, Ti/Ti4O7-Ce electrode maintained stable desalination performance and total organic carbon (TOC) removal efficiency within 60 cycles. This study indicated that Ti/Ti4O7-Ce was a promising electrode for synergistic toxic organics removal and desalination in EAOPs.

Enhancing textile wastewater treatment for subsequent biological processes by integrating electrooxidation and electrocoagulation

ABSTRACT The presence of refractory contaminants in textile wastewater is one of the major concerns while handling them with the biological processes at common effluent treatment. Electro-oxidation (EO) as a standalone process is an insufficient treatment method for the abolition of inorganic contaminants (carbon and non-carbon). By incorporating electrocoagulation (EC) as an associated treatment method after EO, removal of such contaminants becomes easy, which not only makes the treated wastewater fit for biological remediation but also reduces load on biological units. The removal of non-carbonic impurities was assessed in terms of improvement in the chemical oxygen demand (COD) post EC. L25 orthogonal array of experiments was obtained using the Taguchi method. From the S/N ratio plot, the optimal process combination was obtained as, EO with current density = 25 mA/cm2, electrolysis time = 50 min followed by EC with current density = 18 mA/cm2, speed of rotation = 50 rpm and electrolysis time = 40 min. The enhancement in COD and total organic carbon removal efficiencies after EC were 65.11 and 63.57%, respectively, over EO. The biodegradability index also improved from an initial value of 0.098–0.737 post-hybrid treatment. Inorganic carbon reduced from a value of 36.37 mg/L after EO to 0.1 mg/L post EC.

A new catalyst derived from the sulfur-doped metal-organic framework for Fenton-like reaction

Fenton-like reaction exhibits considerable advantages in the remediation of pollutants. To fabricate an efficient catalyst becomes an issue concerning the performance enhancement in Fenton-like reaction. Herein, S-Fe-MOF-400 which was derived from a sulfur-doped metal-organic framework (Fe-MOF), was newly prepared and exhibited high ability for H2O2 activation during Fenton-like reaction. The results showed that the sulfurization effectively reduced the charge transfer resistance (Rct) of S-Fe-MOF-400, and facilitated the charge transfer, consequently enhancing the catalytic performance of S-Fe-MOF-400 in the Fenton-like reaction. XRD analysis revealed that FeS2 was the predominant reactive component in S-Fe-MOF-400 with a regular cubic structure and pronounced crystallinity. Additionally, the presence of low-valent sulfur ensured the availability of Fe (II), thereby facilitating the occurrence of the Fenton reaction. Under optimal conditions, the removal efficiency of pollutants reached 86.7 % within 60 min, resulting in total organic carbon (TOC) removal efficiency at 40.6 %. Quenching experiments and electron paramagnetic resonance (EPR) detections revealed that •OH, 1O2, and O2•− synergistically participated in the Fenton-like reaction, with •OH being the primary active species. The activation process of H2O2 induced by S-Fe-MOF-400 mainly yielded hydroxyl radicals and superoxide radicals. The 1O2 was generated through two following pathways: (i) the transformation of superoxide and hydroxyl radicals, and (ii) the conversion of natural oxygen molecules (O2). This current study illustrated the significant potential for the application of sulfur-modified Fe-MOF in the Fenton-like reaction for pollutant removal.

Efficient tetracycline degradation via flow-through peroxymonosulfate activation by dual heteroatom-doped wood-derived catalytic membrane

The widespread use of antibiotics in the medical industry and in animal husbandry has led to significant environmental pollution. Effective purification of high concentrations of tetracycline (TC) in practical pharmaceutical wastewater remains a substantial challenge. The integration of advanced oxidation with membrane separation technology shows great application potential. In this study, a P and N co-doped balsa wood membrane (PNWM) were fabricated using heteroatomic doped biochar material, aiming to synergize filtration and catalytic oxidation. The catalytic activity of the PNWM/peroxymonosulfate (PMS) system was systematically evaluated. Targeting TC as the pollutant, the PNWM/PMS system achieved a degradation efficiency exceeding 97 % within 30 min and a total organic carbon (TOC) removal efficiency of 63.9 %, surpassing the performance of unmodified wood-based membrane. These excellent results were attributed to the doping of N and P atoms, which increased surface defects and specific area, thereby enhancing the adsorption and degradation of TC by PNWM. The graphite N facilitated electron transfer, while pyridine N served as active sites for PMS activation. Additionally, the low electronegativity of the P formed electronic regions of varying intensities on the PNWM surface, contributing to PMS activation. The membrane process also enhanced mass transfer during the degradation process. Both radical (·OH, SO4·ˉ, O2·ˉ) and non-radical (1O2, electron transfer) pathways cooperated in TC degradation in PNWM/PMS system. Consequently, heteroatom-doped biochar film materials prepared through simple methods provide a promising approach for the effective treatment of refractory organic pollutants in wastewater.

Green and Reflux method synthesis of CeO2/rGO for their characterization and Photodegradation of dye

In this study, cerium oxide (CeO2) was synthesized using a green and eco-friendly solution combustion method with lemongrass as the fuel source. The synthesis process was simple and environmentally friendly, leveraging a straightforward reflux technique to prepare the CeO2/rGO composite. The resulting CeO2 and CeO2/rGO composite was characterized using various analytical techniques, including XRD, FE-SEM, FTIR, EDX, UV-Vis, XPS, and BET analysis. The photocatalytic performance of the CeO2/rGO composite was evaluated through the degradation of Methyl Violet (MV) dye, demonstrating a remarkable photocatalytic efficiency with approximately 99 % degradation following a first-order reaction kinetics. The half-life period (t₁/₂) of the degradation process was determined to be 19.01 minutes, and the rate constant (k) was calculated to be 0.03971 min⁻¹. The study also explored various factors affecting the photocatalytic activity, including pH levels, dye concentration, light source, and the amount of catalyst used. Additionally, scavenger studies were performed to identify the reactive species involved, and the total organic carbon (TOC) removal efficiency was evaluated. The reusability of the CeO2/rGO catalyst was also investigated, demonstrating its potential for sustainable and effective application in environmental remediation processes.

Enhanced Photocatalytic Ozonation Using Modified TiO2 With Designed Nucleophilic and Electrophilic Sites.

Photocatalytic ozonation is considered to be a promising approach for the treatment of refractory organic pollutants, but the design of efficient catalyst remains a challenge. Surface modification provides a potential strategy to improve the activity of photocatalytic ozonation. In this work, density functional theory (DFT) calculations were first performed to check the interaction between O3 and TiO2-OH (surface hydroxylated TiO2) or TiO2-F (surface fluorinated TiO2), and the results suggest that TiO2-OH displays better O3 adsorption and activation than does TiO2-F, which is confirmed by experimental results. The surface hydroxyl groups greatly promote the O3 activation, which is beneficial for the generation of reactive oxygen species (ROS). Importantly, TiO2-OH displays better performance towards pollutants (such as berberine hydrochloride) removal than does TiO2-F and most reported ozonation photocatalysts. The total organic carbon (TOC) removal efficiency reaches 84.4 % within two hours. This work highlights the effect of surface hydroxylation on photocatalytic ozonation and provides ideas for the design of efficient photocatalytic ozonation catalysts.

Exogenous paths regulate electron transfer enhancing sediment phosphorus immobilization

The lack of electron acceptors in anaerobic sediments leads to endogenous phosphorus release and low removal efficiency of organic pollutants. This study introduced electrodes and iron oxides into sediments to construct electron network transport chains to supplement electron acceptors. The sediment total organic carbon (TOC) removal efficiencies of closed-circuit (CC) and closed-circuit with Fe addition (CC-Fe) were estimated to be 1.4 and 1.7 times of the control. Unlike the fluctuation of phosphorus in the overlying water of the controls, the CC-Fe was stabled at 0.04–0.08 mg/L during the 84-d operation. The phosphorus in interstitial water of CC-Fe was 30 % less than in control, whereas in sediment, the redox sensitive phosphorus was increased by 14 %, indicating phosphorus was preferred to fix into sediments rather than interstitial water. This is important to reduce the risk of endogenous phosphorus returning to the overlying water. Microbial community analysis showed that the multiplication of Fonticella in CC-Fe (20 %) was 1.8-fold of control (11 %) which improved the TOC removal efficiency. While electroactive microorganisms accumulated near the electrode reduced the abundance of Fe-reducing bacteria, such as Desulfitobacterium (2.4 %), leading to better phosphorus fixation. These findings suggest a strategy for the efficient bioremediation of endogenous pollution in water, with broader implications for regulating electron transport paths and element cycles in aquatic environments.

Polychloride and benzene ring synergistically boosting photocatalytic degradation and nitrogen fixation performances of carbon nitride

The limited active site exposure, insufficient light absorption and poor charge behavior of carbon nitride (CN) limit its application in environmental remediation and clean energy production. In this study, ultrathin porous CN with enhanced photocatalytic activity was constructed by doping 2,2′,5,5′-Tetrachlorobenzidine (TB) into CN framework. The synergistic effect of polychloride and benzene rings on CN leads to the significant enhancement of range/intensity of visible-light harvest and charge behavior, as well as specific surface area. The optimal sample achieves 100% tetracycline photodegradation efficiency with a rate constant approximately 9 times of pristine CN, and total organic carbon removal efficiency reaches 78.2%. Moreover, photocatalytic ammonia production rate is 7 times of pristine CN. Through active species trapping experiments, ESR, LC-MS, toxicity prediction and DFT calculations, the main active species, degradation pathway, intermediates toxicity and enhanced mechanism of photocatalytic activity are investigated. This work provides a reference for simultaneously regulating the morphology, light absorption and charge behavior of CN-based photocatalyst for addressing environmental and energy concerns.

Supercritical water valorization of a model wastewater containing anxiolytic and antidepressant drugs: Experimental and thermodynamic assessment

This study presents a continuous hydrothermal process based on the supercritical water (ScW) technology for the treatment of pharmaceutical contaminants in wastewater. Using a simulated wastewater as feedstock, which was prepared with 5 psychoactive drugs (sertraline, paroxetine, zolpidem, escitalopram, and clonazepam), the impact of temperature, feed flow rate, and concentration of H2O2 in the degradation of organic matter was investigated. Thermodynamic aspects of the process were also assessed. The optimal conditions of treatment were at a temperature of 692.8 °C, feed flow rate of 6.6 mL/min, and H2O2 concentration in terms of oxidant coefficient (Ox. C.) of 1.03. Under these conditions, the experimental test achieved a total organic carbon removal efficiency (%RTOC) of 85.9 ± 0.5 %. Biochemical oxygen demand (BOD) and chemical oxygen demand (COD) concentrations decreased from 559.0 and 1118.4 mg/L to 66.0 and 152.5 mg/L, respectively. The liquid phase was also assessed by toxicity assays against Artemia salina microcrustaceans. For the gaseous phase, hydrogen was identified as the main component (57.7 %). Additionally, an assessment of the energy efficiency of the process scale-up was investigated. The ScW process showed a promising potential for large-scale continuous operations as an energy-efficient solution for wastewater treatment and valorization due to the concomitant production of H2-rich gas.

Application of the sono-Fenton/UV process on the treatment of table olive processing wastewater

AbstractThe Mediterranean Basin economies of Spain, Italy, Greece, and Turkey depend on the table olive and olive oil industries. Table olive processing wastewater characteristics and quantity depend on olive varietal and processing methods. Olives and processing methods provide phenol, suspended particles, dissolved inorganic solids, and refractory organics. Due of its complexity, conventional methods struggle to tackle table olive processing wastewater. A novel approach to enhanced oxidation processes integrates many ways to boost hydroxyl radical formation and scale up efficiency. UV assisted sono-Fenton process as a modified Fenton process was applied to table olive washing wastewater to achieve high formation of hydroxyl radicals. When UV assisted sono-Fenton experiments executed to determine the optimum reaction conditions, the effects of hydrogen peroxide, ferrous ion concentrations and reaction time on the oxidation of table olive washing wastewater investigated by using a statistical experimental design. Chemical oxygen demand (COD), total organic carbon (TOC) and phenol removal efficiencies were examined by keeping the pH constant. The UV assisted sono-Fenton process achieved 53% phenol, 68% TOC, and 80% COD removal efficiencies. The results show that the UV assisted sono-Fenton process can treat effectively table olive processing wastewater. Optimum reaction conditions for the UV assisted sono-Fenton process were determined. UV assisted sono-Fenton process provides a significant reduction in reaction time and minimizes the costs of process associated with low chemical requirements. So, these optimum reaction conditions were resulted in low sludge production at the UV assisted sono-Fenton process while treating table olive processing wastewater.

Synthesis of iron loaded jackfruit peel biochar through microwave heating as a stable and active heterogenous Fenton catalyst for dye degradation

Iron-loaded biochar derived from jackfruit peels (Fe-JP) was synthesised by pyrolysis in a microwave furnace and iron was loaded onto the peels prior to pyrolysis, facilitated by sonication. The primary objective of the investigation was to examine the degradation process of methylene blue (MB) dye and Acid Red 1 (AR1) dye by the using Fe-JP biochar as a heterogeneous Fenton catalyst. The investigation encompassed an examination of the impact of different operating parameters, such as pH, catalyst dosage, and H2O2 concentration. The synthesised Fenton catalyst underwent characterization using Field Emission scanning electron microscopy (FESEM), Energy Dispersive X-ray (EDX), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) techniques, Fourier transform infrared (FTIR) spectra analysis, Raman spectroscopy, Brunauer-Emmet-Teller (BET) analysis. At a pH of 3, using an initial MB dye concentration of 20 mg/L and initial AR1 dye concentration of 50 mg/L, an 8 mM H2O2 concentration, and a catalyst dose of 2 g/L, the maximum dye removal efficiency reached 96.5 % and 98 % respectively, while the total organic carbon (TOC) removal efficiency reached 68.5 % and 75 % respectively. The observed reaction time under the given experimental conditions was 120 min. The thermal stability of the biochar catalyst was found to be excellent based on the Thermogravimetric analysis (TGA) and Differential Scanning Calorimeter (DSC) studies. The catalysts that were developed demonstrated remarkable durability and negligible leaching of iron, hence enabling their repeated usage in subsequent cycles. The findings of the investigation suggest that the primary mechanism responsible for the degradation of the dye was the surface-based heterogeneous Fenton activity. Additionally, the effect of adsorption on the elimination of colour under varying pH conditions was examined, which had a very low influence in dye degradation (<30 %). The conducted scavenging investigations in the research have indicated the major involvement of hydroxyl radicals (OH) in the degradation process, followed by surface-bound hydroxyl radicals (OHsurface), superoxide radicals (O2−) and ultimately by singlet oxygen radicals (1O2). The study's economic analysis demonstrated that using microwave mode of heating for catalyst synthesis is both green and cost-effective. This observation suggests the possibility of practical implications in the domain of dye degradation.

Magnetic composite photocatalyst NiFe₂O₄/ZnIn₂S₄/biochar for efficient removal of antibiotics in water under visible light: Performance, mechanism and pathway

The widespread presence of antibiotics in aquatic environments, resulting from excessive use and accumulation, has raised significant concerns. A NiFe₂O₄/ZnIn₂S₄/Biochar (NFO/ZIS/BC) magnetic nanocomposite was successfully synthesized, demonstrating significantly enhanced electron-hole separation properties. Comprehensive investigations were conducted to evaluate the impact of various parameters, including catalyst mass, pH, and the presence of co-existing ions on the composite's performance. The nanoparticles of NiFe₂O₄ (NFO) and ZnIn₂S₄ (ZIS) were found to improve the surface stability and sulfamethoxazole removal capabilities of porous biochar, while also demonstrating high total organic carbon removal efficiencies. •O₂⁻ and h⁺ were identified as the predominant reactive oxygen species (ROS) in NFO/ZIS/BC-4 during the degradation process. The degradation outcomes of sulfamethoxazole under natural sunlight and water conditions were consistent with laboratory findings, affirming the robust applicative potential of NFO/ZIS/BC. Density functional theory (DFT) calculations were performed to elucidate the photocatalytic mechanism and identify potential intermediate products. Additionally, the types of heterojunctions present in the system were characterized and discussed. After multiple iterations, NFO/ZIS/BC-4 maintained effective photodegradation capabilities through five cycles. This study presents an effective method for the treatment of antibiotics in aquatic environments, offering significant potential for environmental applications.

Mechanical Enhancement and Water Treatment Efficiency of Nanocomposite PES Membranes: A Study on Akçay Dam Water Filtration Application.

Polymeric membranes are widely used in water treatment because of their ease of fabrication and low cost. The flux and purification performance of membranes can be significantly improved by incorporating appropriate amounts of nanomaterials into the polymeric membrane matrices. In this study, neat poly(ether sulfone) (PES), PES/nano copper oxide (CuO), and PES/nano zinc oxide (ZnO) membranes are fabricated via phase inversion. The pure water flux of the neat PES membrane, which is 355.14 L/m2·h, is increased significantly with the addition of nano-CuO and nano-ZnO, and the pure water fluxes of the nanocomposite membranes vary in the range of 392.65-429.74 L/m2·h. Moreover, nano CuO and nano ZnO-doped PES nanocomposite membranes exhibit higher conductivity, color, total organic carbon, boron, iron, selenium, barium, and total chromium removal efficiencies than neat PES membranes. The membrane surfaces examined by Scanning Electron Microscopy (SEM) after water filtration revealed that those containing 0.5% wt. nano CuO and nano ZnO are more resistant to fouling than the membrane surfaces containing 1% wt. nano CuO and nano ZnO. Based on the results of this study, 0.5% wt. nano ZnO-doped PES membrane is found to be the most suitable membrane for use in water treatment due to its high pure water flux (427.14 L/m2·h), high pollutant removal efficiency, and high fouling resistance. When the mechanical properties of the membranes are examined, the addition of CuO and ZnO nanoparticles increases the membrane stiffness and modulus of elasticity. The addition of 0.5% and 1% for CuO leads to an increase in the modulus of elasticity by 57.95% and 324.43%, respectively, while the addition of 0.5% and 1% for ZnO leads to an increase in the modulus of elasticity by 480.68% and 1802.43%, respectively. At the same time, the tensile strength of the membranes also increases with the addition of nanomaterials.

Optimization and kinetic analysis of electrocoagulation-assisted adsorption for treatment of young landfill leachate

An investigation was conducted on the electrocoagulation treatment of high-strength young landfill leachate using an electrode made of aluminium in a batch electrochemical cell reactor. An iron sheet of 1 m⨯1 m⨯1.1 m (L: B: H) was used to construct the two landfill simulating reactors, both the reactors were operated at different conditions, i.e., one without rainfall (S1) and the other with rainfall (S2). Both reactors have 51% wet and 49% dry waste, which is the typical waste composition of India, and the quantity of waste taken was 450 kg; hence, the generated leachate was treated. This work focuses on the utilization of electrocoagulation as the sole treatment method where coagulation and adsorption occur simultaneously for young landfill leachate. The study employed a central composite design (CCD) to systematically vary the initial pH, current density (CD), and reaction time to examine their impact on the removal efficiency of COD (Chemical oxygen demand), TOC (Total organic carbon), and TSS (Total Suspended Solids). The optimum conditions obtained were a pH of 7.35, a CD of 15.29 mA/cm2, and a reaction duration of 57 min. When the conditions were optimized, the COD, TSS, and TOC removal efficiencies were 83.56%, 73.12%, and 85.58%, respectively. Also, the electrodes depleted 2.78 g of Al/L. In addition, pseudo-first-order and pseudo-second-order kinetics were employed to examine the elimination of contaminants by adsorption on aluminium hydroxide, thereby confirming the adsorption process. After investigation through energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD), with the produced sludge confirmed that electrocoagulation removed a significant amount of metals from landfill leachate.