Contaminants In Wastewater Research Articles

Antibiotic amoxicillin degradation by electrochemical oxidation process: effects of process parameters and degradation pathway at environmentally relevant concentrations.

Amoxicillin (AMX) is a common antibiotic used in both human and veterinary medicine in order to both cure and avoid bacterial infections. Traces of AMX have been found in ground and surface water, urban effluents, water, and wastewater treatment facilities due to its widespread use. The level of hazard and disposal of this class of micropollutants is the reason for concern. Advanced technology is required since conventional wastewater treatment plants are ineffective at eliminating these emerging contaminants. Electrochemical oxidation is a promising method of treating wastewater, which uses electrogenerated radicals to mineralize organic pollutants. This work investigated the detailed process mechanism for AMX degradation utilizing a low-cost, thin, flexible graphite sheet with lower AMX concentrations, initial pH value, voltage, electrolyte concentration, and wastewater matrix. The degradation of AMX by in situ generated hydroxyl radicals is a function of applied voltage and follows pseudo-first-order reaction kinetics. The removal efficiencies of AMX have been achieved up to 99% within 3h. Moreover, intermediate by-products have been identified using liquid chromatography-mass spectrometry, and a plausible pathway has been proposed. This study could serve as a process reference for controlling AMX wastewater contamination via the electrochemical oxidation technique.

Mesoporous Atomically Dispersed Fe Catalysts with Enhanced Nonradical Pathways in Fenton-like Reactions: The Role of SiO2 Templates.

Single-atom catalysts (SACs) are extensively applied in Fenton-like catalytic processes to treat water pollutants. However, the role of the porous structures of SACs supports in catalytic reactions is often overlooked despite its significant contribution to mass diffusion during the reaction. Herein, we adopted a hard-template-assisted approach to fabricate Fe-based SACs (Fe-SACs) featuring a mesoporous architecture. The SiO2 template not only adjusts the pore architecture of the support but also facilitates the conversion of active sites from nanoscale sites to single-atom sites, thereby improving the selectivity for pollutant degradation via nonradical pathways (singlet oxygen and electron transfer mechanism). The experimental results demonstrated that using large-sized SiO2 (∼200 nm) as a template leads to metal aggregation on its surface, forming Fe nanoparticles (Fe-NPs). Fe-NPs exhibit narrow pore structures that prevent peroxymonosulfate (PMS) from being activated, resulting in a slow degradation of pollutants primarily through radical pathways. In contrast, employing small-sized SiO2 (∼10 nm) as a hard template not only produces supports with mesoporous structures but also promotes the building of single-atom active sites. The prepared Fe-SACs effectively activated PMS through nonradical pathways and removed contaminants at a rate k of 0.89 min-1, 33 times faster than Fe-NPs. This template-assisted method sheds light on the synthesis of effective Fenton-like catalysts with porous structures that enhance the efficient breakdown of contaminants in wastewater.

The Environmental Impact of Iodinated Contrast Media: Strategies for Optimized Use and Recycling.

Iodinated contrast media (ICM) is an integral and ubiquitous component of modern diagnostic imaging. Although most radiology practices are familiar with ICM administration and physiological excretion, they may be less aware of how much ICM is wasted on a per exam basis. Furthermore, radiologists may not recognize the environmental fate of discarded ICM waste. In an evolving world where medical practices are increasingly cognizant of their environmental footprint and radiology practices are considered high consumers of resources, it behooves the radiology community to understand the ICM lifecycle and ways to mitigate unnecessary waste. This review article explains the origin and environmental fate of discarded ICM, with special focus on wastewater contamination. Secondly, the article focuses on feasible options to both optimize use and decrease consumable waste. Specifically, the article addresses ICM vial size inventory diversification, multi-use ICM vials, syringeless contrast injectors, and the potential for using multi-energy imaging (dual-energy or photon counting CT) to accomplish these goals. Finally, the authors share their institutional experience participating in an ICM recycling program and its current departmental impact.

In situ construction of CuBi2O4/Bi4O5Br2 Z-scheme heterojunction with enhanced photocatalytic degradation performance for polyphenolic contaminant in wastewater

Photocatalytic technique is one of the clean and promising routes for wastewater purification. In this work, a different CuBi2O4/Bi4O5Br2 Z-scheme heterojunction were successfully prepared via an in-situ mechanical agitation method. The 10% CuBi2O4/Bi4O5Br2 (10% CBO/BOB) heterojunction showed the highest photocatalytic degradation activity for catechin, and ∼99.8% catechin was degrade within 40 min visible light stimulation, which is (0.0757/min) about 6.2-folds and 8.8-folds to that of Bi4O5Br2 (0.0122/min) and CuBi2O4 (0.0086/min), The pH=7 is the optimal reaction condition for catechin degradation. Besides, The photocatalytic degradation capacity of the 10% CBO/BOB heterojunction displayed the positive and negative relationship to the dosage of catalyst and initial concentration of catechin, respectively. The enhanced photocatalytic activity of CuBi2O4/Bi4O5Br2 Z-scheme heterojunction can be ascribed to the improvement of the charge separation and light utilization rate. The results of ESR and trapping experiments revealed that the ·O2-, h+ and ·OH are the primariy reactive substances for catechin degradation. Additionally, the transfer pathway of the photogenerated charges in the CuBi2O4/Bi4O5Br2 Z-scheme heterojunction as revealed by the ESR, Mott-Schottky curve and UV-Vis diffuse reflectance absorption spectroscopy. This work provide a new idea for designing and preparing the novel Bi4O5Br2-based photocatalyst for TCM wastewater purification.

Efficient capture and dual-model fluorescence detection of ReO4− using a TPE-based pyridinium network

99Technetium is one of the highly radioactive contaminants in nuclear wastewater. ReO4− is an ideal substitute for the safe handling of 99TcO4−, its efficient capture and detection are also significant for scarce rhenium resource recovery. However, designing novel materials for the efficient capture and detection of ReO4− and 99TcO4− is still very challenging. Herein, we establish dual-model fluorescence detection for ReO4− via quick ion exchange by a TPE-based cationic polymeric network (TPDC). TPDC displays good sensor performance for ReO4− accompanying the fluorescence enhancement as well as I− accompanying the fluorescence quenching (on-off). Interestingly, the quenched fluorescence can be reopened by ReO4− (off-on) with a slight increase in the detection limit. Moreover, the adsorption capacity for ReO4− reaches 804.2 mg g−1 and the adsorption equilibrium is achieved within 2 min with a kd value of 6.225×105 mL g−1. This work provides a multifunctional material that manifests efficient capture and dual-model fluorescence detection for ReO4− via quick ion exchange accompanying separate or continuous fluorescence change.

Graphene oxide and hydroxyapatite-based composite extracted from fish scale: Synthesis, characterization and water treatment application

In this study the removal of hydrocarbon pollutants from refinery waste water has been described through a convenient adsorption technique using a novel composite of graphene oxide (GO) and n-hydroxyapatite (n-HAp). The main aim was to synthesized composite which are not only sustainable and biodegradable but also exhibit high adsorption capacity and selectivity for hydrocarbon pollutants. Both the HAp and GO were synthesized from fish scales in the laboratory. The synthesized material was then characterized by XRD, FTIR, SEM, and EDX. At 40 °C and 80 min of reaction time, the adsorbent utilized in a batch mode study attained a maximum 97 % organic pollutant adsorption rate. The adsorption activity was spontaneous, exothermic, useful, and it adhered to the pseudo-2nd order kinetic model. without noticeably losing its activity, the adsorbent retained a high level of efficiency over four consecutive cycles. Adsorption of hydrocarbon wastes using composite adsorbent was carried out under batch mode of adsorption experiments. We also studied the effect of dose, temperature, time and pH of the solution on adsorption. Ethanol was used to regenerate the adsorbent, and it was then dried at 70 °C for re-use. The SEM investigation showed that the morphology of huge caves is rough, layered, and wrinkled. The oxygen and phosphate containing groups were found via FT-IR analysis. Freundlich and Langmuir kinetic models were used to measure the adsorption behavior by applying them to the adsorption data. The results demonstrated a strong correlation between the Freundlich isotherm model and the real data. This study showed a highly effective and cost-efficient methodology for the removal of toxic hydrocarbon contaminants in refinery wastewater.

Bioremediation technologies for remediation of dyes from wastewater.

The colored dyes are extensively applied in diverse industrial setups such as textiles, paper, leather, and cosmetics. The unutilized dyes are released in the waste and pose a serious menace to the environment, ecological balance, and human health. Because of their chemical nature, they are extremely resistant to common methods of treatment and often persist in the aquatic environment. A sustainable and eco-friendly approach for treating dye-contaminated wastewater is "bioremediation." This manuscript aims to discuss the exclusive role of diversified microorganisms and plants, immobilized microbial cells/enzymes, microbial consortia, nanomaterials, and combination approaches in the bioremediation of dyes. It also provides a comprehensive understanding of different bio-remedial technologies used to remove dyes from wastewater. In addition, the underlying mechanisms affecting the efficacy of bio-remedial technologies, the latest breakthroughs, challenges, and potential solutions in scaling up, and prospects in this area are also explored. We also detail the noteworthiness of genetic engineering in different bioremediation technologies to solve the issues associated with dye contamination in wastewater and its removal from the environment.

Physicochemical wastewater treatment improvement by hydrodynamic cavitation nanobubbles

Hydrodynamic nanobubble aeration is proposed as an innovative approach to enhancing physicochemical wastewater treatment. Integrating a novel cavitation system to replace conventional aeration significantly improves standard oxygen transfer efficiency and energy consumption. The changes in size and surface charge of air, oxygen (O2), ozone (O3), and chitosan nanobubbles were studied as a function of the reactor diameter. Interestingly, it was found that increasing the radial dispersion length had no significant effect on the measured parameters. Flotation, Coagulation-flocculation (CF), and Advanced Oxidation (AOPs) processes of municipal wastewater comparing convective air and O3 NBs aeration were carried out at pilot plant scale. The use of O3 NBs in the flotation process improves 160 % the suspended solids removal compared to the air-NBs- process. The CF process was evaluated by adding a chitosan dose to the convective processes and monitoring the water quality parameters in real-time. The results demonstrated that the interaction of chitosan with O3 NBs eliminates more than 80 % of the initial chemical oxygen demand (COD). Finally, the AOP carried out with O3 NBs reaches a removal efficiency of 99.8 % total suspended solids and 90 % COD. This modular system presents a practical and efficient alternative for removing municipal and industrial wastewater contaminants.

Enhanced photocatalytic activity of ZnS/TiO2 nanocomposite by nitrogen and tetrafluoromethane plasma treatments

In the present study, the photocatalytic performance of ZnS/TiO2 nanocomposite was investigated through the photodegradation of Acid Blue 113 (AB113) dye under ultraviolet light exposure. TiO2 and ZnS-based nanocomposites suffer from relatively wide bandgap energy and low adsorption capacity which limit their photocatalytic applications. These problems can be suppressed by modifying the surface of nanocomposite particles by the non-thermal plasma. Herein, surface modification of the ZnS/TiO2 nanocomposite was performed using a dielectric-barrier discharge plasma under nitrogen (N2) and tetrafluoromethane (CF4) gases. The characteristics of the plasma-treated nanocomposites were evaluated by XRD, FTIR, Raman, FESEM, EDS, BET, BJH, and DRS analyses. According to the results, by applying plasma treatment, cation and anion vacancies are produced that reduces the band gap energy of the photocatalyst hence improves its performance. The results indicate that the photocatalytic efficiency of the N2-plasma-treated nanocatalyst has been almost two times higher than that of the untreated ZnS/TiO2. It was found that after 25 min of UV irradiation, the AB113 was almost completely degraded in the presence of N2-plasma-treated ZnS/TiO2 nanocomposite (about 95%), whereas, it was degraded by 64% and 46% in the presence of CF4-plasma-treated ZnS/TiO2 and untreated ZnS/TiO2, respectively. This study presents a new approach to designing cost-effective plasma-treated photocatalysts to degrade organic contaminants in wastewater.

Zero Valent Iron/Ni (FeNi) bimetallic heterostructure for scalable fabrication of polyvinylidene fluoride/FeNi films and efficient organic contaminant removal under UV/persulfate system

Surface heterogeneity on nano zero-valent iron (nZVI) with an additional metal is expected to enhance the catalytic performance and stability by inhibiting metal corrosion and leaching. The influence of passivation by Ni/NiO on the stability of nZVI is examined through degradation performance of uniformly aged nZVI and nZVI/Ni (FeNi) samples via photo-Fenton like reactions under UV/potassium persulfate (PS) system. FeNi bimetallic nanoparticles (BNPs) exhibits enhanced degradation than bare nZVI as thin layers of Fe3O4 and NiO which contribute towards photocatalytic degradation and anticorrosive effects by nickel inclusion. FeNi BNPs achieve 98 % degradation for pharmaceutical antibiotic levofloxacin (LEVO) within 120 min and 93 % degradation for Methylene Blue dye (MB) within 60 min, outperforming nZVI. To overcome secondary pollution, a stable polyvinylidene fluoride (PVDF)/FeNi film was fabricated to treat the contaminated water. The free-floating PVDF/FeNi film achieved 95 % degradation of MB and 98.3 % degradation of LEVO, maintaining a degradation efficiency of 95.9 % after five successive cycles. FeNi BNPs are also immobilized in the dialysis membrane resulting in 99.9 % and 99 % removal of MB and LEVO respectively. MB degradation using PVDF/FeNi film is validated through the micro reactor model developed in COMSOL Multiphysics. The parameters determined from the Langmuir-Hinshelwood (L-H) kinetic model include an intrinsic rate constant of 2.18 ×10−6 mol m−3 min−1 and an adsorption constant of 1.43 ×1019 m3 mol−1. This work introduces a cost-effective and scalable technique for the efficient remediation of contaminants in wastewater.

Influence of Electrode Surface Area and Processing Time on Chemical Oxygen Demand (COD) and Total Suspended Solid (TSS) Reduction in Tofu Wastewater Using Electrocoagulation

Electrocoagulation is a wastewater treatment process that uses electrochemical working principles to remove contaminants in solutions or wastewater. Where at the anode (negative current) metal ions are released into solution, while at the cathode (positive current) an electrochemical reaction occurs, namely the release of H2 (hydrogen) gas. Factors that influence the electrocoagulation process include electrode type, current strength, electrode cross-sectional area, process time, voltage, stirring, distance between electrodes, and acidity level (pH). The objective of this research is to investigate the effect of the surface area of the electrode and processing time on the COD and TSS of tofu wastewater. In this research, tofu industry liquid waste was processed using the electrocoagulation method using fixed variables including, Fe-Fe type electrodes, 4 electrodes, acidity level at 4, tofu liquid waste temperature at 25 ̊ C, distance between electrodes 2 cm, electrode thickness 2 mm, test sample of 4 liters and current strength of 13 V. The changing variables used are electrode cross-sectional area (70 cm² and 60 cm²) and processing time (30, 45, 60, 75, 90 minutes). In this study, the best conditions for reducing COD and TSS levels were obtained with a cross-sectional area of ​​70 cm² and a process time of 60 minutes for reducing COD levels and 30 minutes for reducing TSS levels. With a reduction in COD levels of 690.66 mg/L and a reduction in TSS levels of 181.25 mg/L. The results of reducing COD levels do not meet the tofu industry wastewater quality standard of 300 mg/L, and the results of reducing TSS levels meet the tofu industry wastewater quality standard of 200 mg/L.

Revolutionary ZVI-Entrapped Sol-Gel Silica Matrices: Efficient Catalytic Reduction of High-Concentration Halo-Organic Compounds-Addressing Bromoacetic Acid Contamination in Industrial Wastewaters.

The de-halogenation of highly concentrated halo-organic compounds using Zero Valent Iron entrapped in silica matrices as a catalyst was investigated. This study aimed to evaluate the effectiveness of the Zero Valent Iron-entrapped organically modified silica matrices in transforming highly concentrated hazardous halogenated compounds into environmentally benign materials in the presence of BH4-. The Zero Valent Iron-entrapped silica gel matrices were synthesized using the sol-gel method. The de-halogenation products were analyzed using high-performance liquid chromatography. The results suggest that the Zero Valent Iron-entrapped silica matrices are effective catalysts in the de-halogenation reaction of halo-organics by BH4- with 100% efficiency. The current work also highlights the complete de-bromination of harmful wastewater generated by the bromoacetic acid manufacturing industry using Zero Valent Iron-entrapped silica matrices. Therefore, Zero Valent Iron-entrapped silica matrices can be considered potential candidates for the catalytic removal of highly concentrated halo-organic compounds from contaminated water. This technology can play a crucial role in reducing the environmental impact of hazardous substances.

Enhancing the Light‐Driven Photocatalytic Degradation Activity of ZnO Nanoparticles With the Synergistic Incorporation of Er and Tb Elements

ABSTRACTThe existence of organic pollutants in aqueous media has become a vital issue and a critical threat to human health, where organic toxic dyes represent the major contaminants in wastewater. Over the past few years, photocatalytic techniques have garnered a lot of interest in dye removal from wastewater. In this study, a series of ErxTbxZn1 − 2xO nanophotocatalysts (where x = 0.00, 0.01, 0.03, and 0.05) were synthesized and coded as ZET0, ZET1, ZET2, and ZET3 NPs (nanoparticles). The chemical and physical characteristics of the NPs were investigated using Fourier‐transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy‐dispersive X‐ray (EDX) spectroscopy, and ultraviolet–visible diffuse reflectance spectroscopy (UV–vis DRS) techniques. Further examination by performing photocatalytic experiments, ZET1 NPs demonstrated effective Rhodamine B (RhB) dye degradation within 60 min. It was found that the kinetic rate constant values were 0.008, 0.097, 0.050, and 0.040 min−1 for ZET0, ZET1, ZET2, and ZET3 NPs, respectively. Aside from their remarkable photocatalytic degradation efficiency, these ZET1 photocatalysts are highly stable even after five consecutive cycles. In addition, the active species test revealed that the primary oxidation species involved in the photocatalytic process are holes (h+) and hydroxyl radicals (•OH), and a possible photocatalytic mechanism for degrading RhB by ZET1 photocatalysts was tentatively proposed. The enhancement of the photocatalytic degradation efficiency is due to the low recombination rate of photogenerated charge carriers, as well as a strong synergistic impact of Tb, Er, and ZnO components. Thus, the current study could offer a versatile strategy for the design of new and effective nano photocatalysts for wastewater purification in the future.

Versatile silicate-modified hydrochar based on Scutellaria baicalensis-residue for efficiently removing heavy metal-antibiotic co-contamination and relevant bio-contaminants from wastewater

In this study, we utilized typical Chinese medicine herbal residues (CMHRs)－Scutellaria baicalensis (Scutellaria baicalensis Georgi) residue (SR), as the raw material and employed Na2SiO3 and Fe2(SO4)3 as modifying agents to fabricate a novel and multifunctional hydrochar (FeSi-SRHC), which was designed for comprehensive removal of typical contaminants such as Cu2+, Zn2+, tetracycline (TC), and ciprofloxacin (CIP), along with relevant bio-contaminants (resistant bacteria (RBs) and resistance genes (RGs)) present in wastewater. Based on the analysis of adsorption kinetics and Freundlich isotherm, it was found that FeSi-SRHC exhibited physical monolayer adsorption for Cu2+/Zn2+ while mainly chemical multilayer adsorption for TC/CIP in single-contamination system. Furthermore, Langmuir isotherm demonstrated excellent adsorption capacity of FeSi-SRHC towards Cu2+/Zn2+/TC/CIP with maximum capacities of 255.75, 265.26, 425.53, and 404.86 mg/g, respectively. In the co-contamination system, the presence of Cu2+, Zn2+, TC, and CIP exhibited varying degrees of inhibitory or promotive effects on the mutual adsorption by FeSi-SRHC. This divergence stemmed from differences in complexation intensities and concentration ratios among diverse co-existing contaminants. Based on XPS and Density Functional Theory (DFT) analyses, the adsorption process for Cu2+, Zn2+, TC, and CIP by FeSi-SRHC primarily involves pore fill, complexation reactions, ion exchange, hydrogen bonding, π-π stacking interactions, and electrostatic interactions. Bio-contaminant removal experiments revealed that the release of baicalin and wogonoside from FeSi-SRHC disrupts the structure of RBs cells and compromises the integrity of resistance plasmids. The practical application experiment showed that FeSi-SRHC displayed favorable performance for removing heavy metals, antibiotics, and bio-contaminants in actual wastewater. This study presented a “Treating waste with waste” strategy, which provided a method with low carbon, eco-friendly, and inexpensive for CMHRs resources and turning waste into treasure while proposing a idea to address the challenges associated with treating heavy metal, antibiotic, and bio-contaminant contamination in wastewater.

Towards Achieving Circular Economy in the Production of Silica from Rice Husk as a Sustainable Adsorbent

The growing concern over water pollution and waste management requires innovative solutions that promote resource efficiency within a circular economy. This study aims to utilize rice husk (RH) as a sustainable feedstock to develop highly porous silica particles and generate valuable by-products, addressing the dual challenges of waste reduction and water contamination. We hypothesize that optimizing the production of amorphous silica from acid-washed RH will enhance its adsorptive properties and facilitate the concurrent generation of bio-oil and syngas. Amorphous silica particles were extracted from acid-washed RH with a yield of 15 wt% using a combination of acid washing at 100 °C, pyrolysis at 500 °C, and calcination at 700 °C with controlled heating at 2 °C/min. The optimized material (RH2-SiO2), composed of small (60–200 nm) and large (50–200 µm) particles, had a specific surface area of 320 m2/g, with funnel-shaped pores with diameters from 17 nm to 4 nm and showed a maximum cadmium adsorption capacity of 407 mg Cd/g SiO2. Additionally, the pyrolysis process yielded CO-rich syngas and bio-oil with an elevated phenolic content, demonstrating a higher bio-oil yield and reduced gas production compared to untreated RH. Some limitations were identified, including the need for bio-oil upgrading, further research into the application of RH2-SiO2 for wastewater treatment, and the scaling-up of adsorbent production. Despite the challenges, these results contribute to the development of a promising adsorbent for water pollution control while enhancing the value of agricultural waste and moving closer to a circular economy model.

Fabrication of 3D flower-shaped MgAl-LDHs with inducing CuMOF for improving its adsorption and antibacterial performance

Chronic and inappropriate use of antibiotics, antibiotic residue, and bacterial infections present a significant threat to both the environment and human health. This study focused on the effective remediation of wastewater contaminants through the synthesis of Cu-based metal-organic framework (CuMOF) conjugated with layered double hydroxide (LDHs) via hydrothermal processing, resulting in the development of a novel three-dimensional (3D) flower-shaped CuMOF@LDHs (Fc-LDHs) hybrid materials. After being characterized by SEM, FT-IR, XRD, zeta potential and BET, the obtained Fc-LDHs was applied to adsorption of antibiotics, and its antibacterial activity was also investigated. It indicated that Fc-LDHs exhibited excellent performance in both adsorption and antibacterial activity. Utilizing tetracycline (TC) as a representative antibiotic, the influence of various parameters on the adsorption efficiency was examined. The study revealed that an adsorbent mass of 0.08 g could achieve a removal efficiency of 94.2 % for TC at an initial concentration of 50 mg/L within 90 min, with the removal rate remaining at 72.6 % after four cycles of adsorption-desorption. It was also found that the adsorption mechanism was consistent with the Freundlich isothermal model and the pseudo-second-order kinetic model. The exceptional adsorption properties were primarily ascribed to the synergistic effects of electrostatic interactions, pore filling, chelation and hydrogen bonding interactions between Fc-LDHs and TC. Simultaneously, the antibacterial rates of Fc-LDHs reached to 90.3 % and 95.7 % against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), respectively. In conclusion, Fc-LDHs proved to be a highly efficient remedy for addressing antibiotic and antibacterial pollution, functioning both as a proficient adsorbent and antibacterial agent.

Effect of MoS2 Morphology on the Photocatalytic Degradation of 4-Nitrophenol to Aminophenol

Nitroaromatic compounds are frequently detected as contaminants in industrial or agricultural wastewaters. Wastewater discharge contributes to nitrophenol pollution of the aquatic environment. Toxicity and carcinogenicity of 4-nitrophenol cause serious impact on water bodies. The present study is devoted to investigates the photocatalytic degradation of p-nitrophenol to aminophenol by MoS2 photocatalyst. MoS2 nanoparticles were synthesized via a hydrothermal process and further characterized by using X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), High resolution transmission microscopy (HRTEM), UV-Visible spectroscopy, Brunauer–Emmett–Teller (BET), and X-ray photoelectron spectroscopy (XPS). X-ray analysis revealed the presence of 2H phase of MoS2 and XPS analysis determined its various oxidation states. Fourier Transformation Infra-Red Spectroscopy (FTIR) and Thermogravimetric analyses (TGA) were used to study the functional group and thermal stability. UV-Visible spectroscopy was used to study the degradation of 4-nitrophenol and reaction kinetics. Investigation results showed a significant effect of nanosheets over nanoflower morphology for degradation efficiency of 4 nitrophenol to aminophenol under natural Sunlight.

Comparative Study of Biosorption and Traditional Methods for Heavy Metal Removal from Industrial Wastewater in Panipat

In this research paper, I have thoroughy described about the topic Comparative Study of Biosorption and Traditional Methods for Heavy Metal Removal from Industrial Wastewater in Panipat.” Industrial wastewater contamination by toxic heavy metals poses a significant environmental threat globally, especially in rapidly industrializing regions like Panipat District in Haryana, India. Panipat, renowned for its extensive textile and chemical industries, generates substantial volumes of wastewater laden with heavy metals such as lead (Pb), cadmium (Cd), and mercury (Hg). Recent studies have revealed that the concentrations of these metals in Panipat's industrial effluents frequently surpass the permissible limits set by environmental regulations. Traditional methods for heavy metal removal, including chemical precipitation and ion exchange, are widely utilized but often entail high operational costs and the generation of secondary pollutants like sludge. Biosorption, an emerging and sustainable technology, offers a promising alternative by utilizing biological materials such as algae, bacteria, and agricultural waste to adsorb heavy metals from wastewater. This study aims to investigate the effectiveness, cost-effectiveness, and environmental impact of biosorption compared to traditional methods in Panipat District. By examining heavy metal removal efficiencies, conducting cost analysis, and assessing environmental implications, this research seeks to provide valuable insights into sustainable wastewater treatment practices.

Natural and synthetic hydrogels for dye removal

In recent years, dyes have been classified as recalcitrant contaminants in wastewater, exhibiting significant toxicological characteristics for flora, fauna, and humans. Various techniques are currently being studied for the remediation of water contaminated with dyes. Among the most relevant alternative technologies are bioadsorption, biocoagulation, the use of composite materials, advanced oxidation processes, etc. However, these methods have some disadvantages. Similarly, the use of hydrogels specifically designed for the treatment of contaminated water is a viable and effective alternative. This is due to their ability to adsorb large amounts of water, high porosity, and multiple active sites. This research describes dyes, their classification,toxicity, and ecotoxicity. Additionally, it presents some alternative treatments for water remediation, emphasizing the design of hydrogels based on synthetic and natural macromolecules. These hydrogels are proposed as promising materials for the removal of dyes from contaminated water. The aim of this research is to highlight synthetic and natural hydrogels as promising materials for the decontamination of water from dyes.

Removal of contaminants in paper dyeing wastewater by Fenton and photo-Fenton processes with biological treatment

Due to the production of huge quantity of potentially toxic and recalcitrant pollutants, which cannot be completely decomposed with conventional biological wastewater treatment processes, in the paper industry, reliable treatment processes are highly required. This study conducted effective experiments of different series of processes to decompose persistent contaminants in the paper wastewater under controlled conditions of the used processes to meet the effluent quality standards of Korea Ministry of Environment in terms of CODMn (< 130 mg/L). For Biological treatment, Fenton, and photo-Fenton processes, various operational parameters were adjusted to determine the optimal conditions for CODMn value. Due to large quantity of refractory contaminants in the wastewater, single treatment process was not enough to meet the requirement of CODMn. Herein, we achieved the goal with two approaches: (1) secondary Fenton oxidation after biological and primary Fenton treatments, and (2) photo-Fenton treatment after biological treatment alone. The secondary Fenton oxidation process is an additional process operated under the same condition of the primary Fenton treatment to treat the effluent from the primary Fenton treatment. Ultimately, the residual CODMn concentrations of the secondary Fenton and single photo-Fenton treatment were 62.7 and 85.3 mg/L, respectively. However, the secondary Fenton required larger amounts of reagents and produced significant amounts of sludge, which require post-treatment, compared to single photo-Fenton treatment. Therefore, it suggests that the application of photo-Fenton was more efficient than the secondary Fenton in terms of economic feasibility and post-treatment requirement.