Industrial Effluents Research Articles

Integrating ANSYS Fluent Simulation and Aspen Plus for efficient heavy metal ion removal with de-oiled cake

In this study bio-flocculant extracted from the de-oiled cake, a common waste generated while producing oil was used to treat an electroplating industrial effluent. A comprehensive analysis of flocculation efficiency in a simulated reactor using ANSYS Workbench - Fluent, with a focus on optimizing impeller position was carried out. The findings reveal that the optimal impeller position is 2 cm from the tank base, where maximum turbulent kinetic energy (0.02577 m2/s2) and dissipation rate (22.19 m2/s3) were achieved at 200 RPM, enhancing flocculation efficacy. Furthermore, the study identifies 0.5 g L−1 as the optimal flocculant dosage, resulting in 72.70 % and 89.38 % removal of Ni(II) and Cr(VI), respectively. The flocculation process was determined to follow second-order kinetics, with significant improvements in collision efficiency and particle aggregation at the optimized dosage. Fourier Transform Infrared spectroscopy analysis confirmed chemical interactions leading to flocculation, while zeta potential and particle size distribution studies corroborated the stability and effectiveness of the process. A techno-economic analysis was conducted, estimating the total capital investment required for pilot and industrial-scale implementations, highlighting the feasibility and scalability of the proposed treatment method. A holistic framework for enhancing industrial effluent treatment processes by integrated computational fluid dynamics, kinetic studies, and economic evaluation, is the novelty of this research.

Biosorption of heavy metal ions using a wood-rot fungus Schizophyllum commune

In this study, the ability of live mycelia of Schizophyllum commune to remove heavy metals from aqueous solution was investigated. The influence of various experimental parameters, such as pH, temperature, and contact time on the biosorption process was investigated. The maximum biosorption capacity using live biomass was found as 81.5, 90.71, 70.18, and 66.18 mg/g for Pb(II), Sr(II), Zn(II), and Cd(II), respectively, at optimized conditions. The biosorption process reaches equilibrium between 180 and 240 min for the tested metal ions. The experimental data were used to study biosorption isotherm and kinetics models. The thermodynamic parameters, ΔG°, ΔH°, and ΔS°, showed that the biosorption process was endothermic and spontaneous at 303–343 K. SEM images revealed that the presence of metal ions altered the morphology of fungal hyphae. The presence of Pb(II), Sr(II), Zn(II), and Cd(II)on the fungal mycelia was confirmed using SEM-EDX. FTIR spectroscopy of biomass showed the involvement of functional groups like, -CH, amino acid, fatty acid, carboxyl group, and alkane and alkyl groups in adsorption of heavy metal ions. The adsorption capacity of S. commune for removal of heavy metals under the optimized conditions was Sr(II) > Pb(II) > Zn(II) > Cd(II). Thus, the study demonstrated an application of Schizophyllum commune for efficient removal of heavy metals from metal-contaminated water or industrial effluents.

Evaluating the efficacy of palm waste in adsorption processes for wastewater treatment: A review

AbstractThe growing environmental concerns related to industrial effluents and waste underscore the urgent need for sustainable and cost‐effective wastewater treatment solutions. This review investigates the efficacy of palm waste‐derived adsorbents for removing heavy metals and organic pollutants from wastewater. It explores various modifications—including physical, chemical, and nanomaterial enhancements—applied to palm waste materials such as palm kernel shells, empty fruit bunches, and palm oil fuel ash, aimed at improving their adsorption capacities. The review reveals that these modified palm waste adsorbents demonstrate high removal efficiencies for contaminants like Cu(II), Pb(II), and organic dyes, often surpassing conventional adsorbents. Nonetheless, challenges remain, such as optimizing adsorbent preparation, understanding adsorption mechanisms in multi‐component systems, and enhancing adsorbent reusability. This review highlights the need for continued research to address these issues and advance the application of palm waste‐based materials in sustainable wastewater treatment.

Recycling and breakdown photodegradation processes cost of BEN-TiQD via different photodegradation processes of Brilliant Green S dye and industrial effluents

The development of efficient photocatalytic materials for environmental remediation is of paramount importance. This study reports the synthesis and characterization of novel bentonite-titanium dioxide quantum dot (BEN-TiQD) nanocomposites for the photodegradation of Brilliant Green S, a prominent industrial pollutant. The nanocomposites were prepared via a co-precipitation method, ensuring uniform dispersion of TiO2 nanoparticles on the bentonite (BEN) surface, followed by heat treatment to achieve optimal crystallinity and surface properties. Comprehensive characterization techniques, including FTIR, XRD, SEM, BET surface area analysis, and optical spectroscopy, were employed to elucidate the structural, morphological, and photophysical characteristics of the composites. The BEN-TiQD nanocomposites exhibited an augmented surface area of 277.75 m2/g, surpassing BEN alone by more than threefold, and an intermediate bandgap of 3.17 eV, rendering them suitable for visible light absorption and photocatalytic applications. The photocatalytic efficacy of BEN-TiQD was evaluated by monitoring the degradation of Brilliant Green S under various operational parameters. The nanocomposites demonstrated superior photocatalytic performance, with a rate constant of 22.24 × 10−3 s−1, significantly only lower than TiQD (28.32 × 10−3 s−1) by nearly about 21.5 %. The enhanced activity was attributed to the quantum size effect of the incorporated TiO2 quantum dots, optimizing light absorption and charge separation. Mechanistic studies revealed the generation of reactive oxygen species, particularly hydroxyl radicals, as the primary drivers of dye degradation. The reusability of BEN-TiQD was evaluated through multiple photocatalytic cycles, exhibiting remarkable stability for up to six consecutive cycles. However, a gradual decline in photodegradation efficiency was observed after prolonged sunlight exposure, likely due to particle agglomeration and reduced surface area. This research contributes to the field of environmental remediation by developing a novel composite material that synergistically combines the adsorptive properties of BEN with the photocatalytic capabilities of titanium dioxide quantum dots. The findings pave the way for further exploration and optimization of these composites for sustainable and efficient treatment of industrial dyes and effluents, addressing critical environmental challenges.

Highly-efficient recovery of silver from industrial cyanide-based plating effluent on TiO2/activated carbon composites

The release of silver-containing wastewater is an economic loss. In this works, the silver ions in the cyanide-based plating effluent of jewelry effluent was systematic recovered by the photocatalytic process using commercial semiconductors (TiO2, ZnO, Bi2O3 and WO3) and activated carbon (AC) enhanced semiconductors as the photocatalysts. The preliminary results demonstrated that the highest photocatalytic silver recovery was achieved via the use of TiO2 nanoparticles (NPs), ascribing to its better textural property that provided abundant active sites to undergo the reaction. The intrinsic property and activity of TiO2 were significantly improved in the presence of proper content of AC. Approximately 94% of silver was recovered within 45 min through the TiO2/AC with 14.9 wt.% AC (TiO2/AC1) under the UV-vis irradiation due to the act of AC as the conductive pathway for electron migration from CB of TiO2 along its surface, thus prolonging the lifetime of electron-hole pairs. Although a marked decrease in photocatalytic activity of the best composite was detected after the 4th use (∼50%), it exhibited an outstanding antibacterial ability compared with TiO2 and fresh one in dark environment. The work offers the avenue to design the photocatalyst for recovering the precious metals from industrial effluent and broaden the application of such recovered metal decorated photocatalyst for practical use.

From Pollution to Preservation: Impacts of the Namami Gange Project on the Ganga River Ecosystem in the Varanasi Urban Area

The Namami Gange project was started by the Government of India, in 2014 as a mission to rejuvenate the Ganga River from acute pollution and environmental degradation, achingly throwing a plight on this holy waterway. This research paper explores the impact of the Namami Gange project on the holy river Ganga in Varanasi Urban Area, Uttar Pradesh. The study is based on a multi-disciplinary approach with the help of water quality monitoring, sources of pollution, and assessment of the measures followed under the Namami Gange Program. For monitoring the water quality, the parameters adopted in the present research are temperature, pH, conductivity, DO (dissolved oxygen), BOD (biochemical oxygen demand), FC (fecal coliform), and TC (total coliform), before and after the Namami Gange program implementation. Results show a visible improvement in water quality with major reductions in BOD and coliform levels, reflecting better oxygenation and reduced organic pollution. In this direction, the work pertaining to the establishment of STPs (Sewage Treatment Plants) and upgrading of existing infrastructure has been extremely crucial for mitigating the inflows of untreated sewage and industrial effluents into the river. The research also investigated the program's ecological effects on the restoration of aquatic habitats and biodiversity recolonization in a few river reaches. Public awareness campaigns and community participation programs were also completed with huge responses from the local population and pilgrims to enhance the sense of stewardship, which leads to greater sustainability and reduced pollution. The research, however, portrays that some of the lingering challenges pertain to continuous monitoring, STP maintenance, and non-point sources of pollution. More importantly, this would call for a holistic invasive management approach so that these positive outcomes as potentials of the Namami Gange program do not go astray. Overall, the paper provides valuable insights into the efficacy of large-scale environmental interventions and their potential to revive and preserve vital water resources like the Ganga River in Varanasi.

Production of New Activated Carbon from Agricultural Waste and its Use as an Eco-Friendly Solution for Removing Copper Ions from Industrial Effluents

Production of New Activated Carbon from Agricultural Waste and its Use as an Eco-Friendly Solution for Removing Copper Ions from Industrial Effluents

Tissue-specific distribution and fatty acid content of PFAS in the northern Bohai Sea fish: risk-benefit assessment of legacy PFAS and emerging alternatives

This study aimed to examine the distribution of poly- and perfluoroalkyl substances (PFAS) in 15 marine fish species from the northern Bohai Sea, investigate their sources of contamination, and evaluate the benefits-risks associated with the concurrent consumption of fish fatty acids and PFAS. The ∑PFAS concentrations in fish ranged from 9.38 to 262.92ng·g-1 (dry weight). The highest PFAS levels were found in the viscera and gills, while the lowest levels were found in the muscles. Industrial effluents and sewage treatment plant discharges were the primary sources of PFAS contamination. The individual PFAS concentrations in fish were insignificantly correlated with their trophic levels (p > 0.05). However, the concentrations of hexafluoropropylene oxide dimer acid (HFPO-DA) or long-chain PFAS (C > 8) significantly increased with fish size (e.g., total length, weight) and lipid content (p < 0.001). The benefit-risk analysis suggests that HPFO-DA poses a higher health risk than perfluorooctanoic acid (PFOA) in fish (p<0.05). Long-term consumption of contaminated fish may significantly increase human serum PFOA concentration and kidney cancer risk (p<0.05). Daily consumption of 5g (wet weight) muscle from Ditrema temmincki and Konosirus punctatus is recommended to meet the requirements for fatty acid supplementation without posing health risks.

Cost-Effective Synthesis of MXene Cadmium Sulfide (CdS) for Heavy Metal Removal.

Background Environmental contamination resulting from the release of untreated industrial wastewater has emerged as a critical worldwide issue. These effluents frequently have high levels of heavy metals and antibiotics, which are bad for aquatic ecosystems and human health. Oftentimes, conventional wastewater treatment techniques fall short of effectively eliminating these pollutants. Innovative materials that may efficiently absorb or break down contaminants from contaminated water sources are, therefore, desperately needed. Hydrothermally produced MXene cadmium sulfide (CdS) composites have shown great promise as an adsorbent material because of their special qualities, which include high surface area, chemical stability, and customizable surface functions that improve their adsorption capacity for heavy metals and antibiotics alike. Aim The aim of this study is to produce MXene-CdS nanoparticles in a cost-effective method for the simultaneous removal of heavy metals from aqueous contaminants for water pollution control. Methods and materials MXenes were synthesized by selectively etching Ti3AlC2 MAX-phase ceramics using aqueous HF. CdS nanoparticles were synthesized separately and integrated with MXenes via a hydrothermal process. The resulting MXene CdS nanocomposites were characterized using scanning electron microscopy (SEM) for morphology, energy dispersion spectrum (EDS) for elemental composition, X-ray diffraction(XRD) study for phase identification, and removal of heavy metals viaMXene CdS. Results Consistent distribution of CdS nanoparticles on the MXene surface and the creation of MXene CdS nanomembranes with a well-defined shape were observed by SEM analysis. Ti, C, Cd, and S elements, indiciaries of a successful composite formation, were confirmed to be present by EDS. The crystalline structure of both the MXene and CdS phases was confirmed by the distinctive peaks seen in the XRD patterns. MXene-CdS composites facilitate the effective removal of chromium ions from contaminated water. The excellent hydrophilicity of the produced nanomembrane allowed for effective interaction with watery contaminants. Conclusion This study showcases the successful synthesis and characterization of MXene-CdS nanocomposites for environmental remediation, particularly in removing toxic metals like chromium from industrial effluents. SEM analysis confirmed the uniform distribution of CdS nanoparticles on the MXene surface, while elemental composition validated their integration. XRD analysis confirmed the crystalline structures of both components. The nanocomposite exhibited excellent hydrophilicity, enhancing the efficient adsorption of heavy metals. Its large surface area and chemical stability contribute to high adsorption efficiency, making it ideal for wastewater treatment. The scalable synthesis process supports practical applications. This research highlights MXene-CdS nanocomposites as a cost-effective, sustainable solution for water pollution control.

Effect of Al doping on the structural, optical and photocatalytic properties of sol-gel spin-coated NiO thin films

Nanostructured NiO thin films are renowned for their catalytic activity and potential for degradation of industrial effluents. In this study, Al-doped NiO (Ni1-xAlxO with x = 0, 0.02, 0.04, 0.06, and 0.08) thin films were synthesized by sol–gel spin coating, and the influence of Al doping on their physical properties, surface morphology, optical band gap, and photo-catalytic performance was investigated. X-ray diffraction (XRD) analysis confirmed the high crystallinity of the thin films and revealed a pronounced doping effect on parameters such as crystallite size, microstrain, and dislocation density. Scanning electron microscopy (SEM) revealed the formation of spherical nanoparticles with particle sizes ranging from 26 nm to 11 nm. The elemental composition was verified through energy-dispersive x-ray (EDX) analysis. The optical bandgap of the prepared films was determined through UV-visible spectroscopy. The Ni0.98Al0.02O films exhibited the lowest PL intensity, indicating a reduced recombination rate. To assess the photo-degradation capability of the prepared thin film catalysts, industrial effluent Indigo Carmine was employed as a test compound. The Ni0.98Al0.02O sample demonstrated the highest degradation efficiency, achieving about 96% degradation within 2 h of UV–vis light irradiation. Furthermore, the degradation followed pseudo-first-order kinetics.

Competent CuS QDs@Fe MIL101 heterojunction for Sunlight-driven degradation of pharmaceutical contaminants from wastewater

In this study, we introduce an advanced photocatalyst developed by integrating copper sulfide quantum dots (CuS QDs) with an iron-based metal–organic framework (MOF), specifically Fe MIL101. The resulting CuS QDs@Fe MIL101 photocatalyst is engineered to efficiently degrade meloxicam (MLX) under simulated sunlight. The heterojunctions were generated by incorporating different concentrations of CuS QDs (5 %, 10 %, 15 %, 20 %, and 50 %) into the Fe MIL101 MOF matrix using the microwave-assisted hydrothermal method. The results of the XRD and the TEM studies confirmed the formation of the heterojunctions, which maintain the structural integrity of both CuS QDs and Fe MIL101. The BET measurements indicated a decrease in surface area upon CuS QDs incorporation, attributed to porés blockage and structural modifications. UV–Vis diffuse reflectance spectroscopy (DRS) revealed a redshift in absorption edges as CuS QDs content increased, enhancing visible light absorption. Photoluminescence (PL) investigations revealed that the 15 % CuS QDs@Fe MIL101 heterojunction had an effective charge separation and low recombination rates. The zeta potential analysis revealed a negative surface charge, indicating an overall electronegative characteristic. The photocatalytic performance, assessed through the degradation of MLX, demonstrated that the 15 % CuS QDs@Fe MIL101 heterojunction achieved the maximum degradation efficiency, reaching 96 % after 45 min of irradiation at a dosage of 0.1 g/L. This exceptional performance is attributed to potent charge separation, improving visible light absorption, high surface area and adsorption capacity. Various scavengers were used to investigate the roles of different reactive species, revealing holes as the predominant active species in the photocatalytic degradation process. These results highlight the potential of 15 % CuS QDs@Fe MIL101 heterojunctions as efficient photocatalyst for environmental remediation from pharmaceutical pollutants under simulated sunlight. These findings highlight the potential for application of CuS QDs@Fe MIL101 in real-world wastewater treatment systems, particularly in addressing pharmaceutical contaminants like meloxicam in industrial effluents.

Seasonal nitrogen removal in an outdoor microalgal polyculture at Nordic conditions.

Microalgal solutions to clean waste streams and produce biomass were evaluated in Nordic conditions during winter, spring, and autumn in Southeast Sweden. The study investigated nitrogen (N) removal, biomass quality, and safety by treating industrial leachate water with a polyculture of local microalgae and bacteria in open raceway ponds, supplied with industrial CO2 effluent. Total N (TN) removal was higher in spring (1.5 g-2d-1), due to beneficial light conditions compared to winter and autumn (0.1 and 0.09 g-2d-1). Light, TN, and N species influenced the microalgal community (dominated by Chlorophyta), while the bacterial community remained stable throughout seasons with a large proportion of cyanobacteria. Winter conditions promoted biomass protein (19.6-26.7%) whereas lipids and carbohydrates were highest during spring (11.4-18.4 and 15.4-19.8%). Biomass toxin and metal content were below safety levels for fodder, but due to the potential presence of toxic strains, biofuels or fertilizer could be suitable applications for the algal biomass. PRACTITIONER POINTS: Microalgal removal of nitrogen from leachate water was evaluated in Nordic conditions during winter, spring, and autumn. Total nitrogen removal was highest in spring (1.5 g-2d-1), due to beneficial light conditions for autotrophic growth. Use of local polyculture made the cultivation more stable on a seasonal (light) and short-term (N-species changes) scale. Toxic elements in produced algal biomass were below legal thresholds for upcycling.

Tetracycline degradation for wastewater treatment based on ozone nanobubbles advanced oxidation processes (AOPs) – Focus on nanobubbles formation, degradation kinetics, mechanism and effects of water composition

Presence of pharmaceuticals, especially antibiotics, in industrial and domestic effluents causes serious damage to the environment. Classic wastewater treatment processes, in particular conventional biological treatment methods, are not sufficient to rapidly eliminate antibiotics. Typically, Advanced Oxidation Processes (AOPs) based on activation of hydrogen peroxide, ozone or persulfate for production of particular type of radical species or singlet oxygen are used. A one of cutting-edge technologies to increase effectiveness of AOPs based on ozone are nanobubbles based processes. Thus, this paper focuses on utilization of ozone in the form of nanobubbles for degradation of tetracycline (TC). The effects of several reaction parameters, such as antibiotic concentration, ozone intake, pH, presence of salts, were investigated. This study revealed that the presence of ozone nanobubbles had a substantial positive impact on the degradation of TC. This improvement may be attributed to the enhanced mass transfer and the production of reactive radicals that occur during the collapse of the nanobubbles. Identification of radical species revealed a significant contribution of hydroxyl radicals in the degradation of the antibiotic. AOP process based on O3 nanobubbles was most (•OH) and superoxide (O2–) effective with 100 % degradation efficiency of 100 mg/L TC within 20 min at 8 mg/L concentration of ozone. Based on identified by LC-MS intermediates a degradation mechanism has been described. Degradation of TC and intermediates transformations included methylation, hydroxylation, ring-opening steps as well as cleavage of C-N bonds. This research introduces a novel technique combining nanobubbles with advanced oxidation processes (AOPs), which is anticipated to provide enhanced efficiency and environmental sustainability.

Development and assessment of vanadium-based metal–organic frameworks for the effective elimination of hazardous pesticides from aqueous solutions: Mechanism of uptake, adsorption capacities, rate of uptake, and enhancement via the Box-Behnken design

Vanadium metal–organic frameworks (V-MOF) has a great potential to remove contaminants from water that come from agriculture wastewater methyl parathion (MP) pesticides with high effectiveness. Using a variety of methods, such as SEM, FT-IR, XPS), XRD, and BET analysis, the adsorbent was successfully synthesized and characterized. The dimensions of the pores measured at 1.33 nm correspond to the classification of micropores under the IUPAC system. Before the adsorption process, the material had a surface area of 1489.42 m2/g and a pore volume of 0.98 cc/g. After MP adsorption, the surface area, pore size, and pore volume decreased to 1268.42 m2/g, 1.12 nm, and 0.64 cc/g, respectively. Changes in the material’s physical properties indicate that the adsorption process had an effect. 7.2 was the result of controlling the point of zero charge through surface characterization. This information suggests that the surface of the adsorbent has a positive charge at pH below 7.2 and at the pH higher than this value the surface will have a negative charge. It was also looked into how pH affected the adsorption equilibrium. Although fitting to Langmuir isothermally, the kinetics of MP adsorption onto V-MOF are pseudo-second-order fitting. It is very probable that chemisorption was the mode of adsorption because the adsorption energy was 23.62 kJ.mol−1. The enthalpy (ΔHo) values obtained as a result of studying the thermodynamic parameters are positive, demonstrating that, within this temperature range, the pesticide adsorption process was endothermic., measuring 32.79 kJ.mol−1. Entropy (ΔSo) readings that are positive indicate that the system’s randomness increased during the adsorption process, reaching 119 J.mol−1K−1, and with rising temperatures, the negative of ΔGo rise. The effectiveness of the recommended adsorbent was evaluated by filtering wastewater samples in a laboratory environment. It is hypothesized that V-MOF and MP will interact by pore filling, π-π interaction, H-bonding, electrostatic contact, and other possible methods. Considering the specifics of this interaction in great detail is essential to comprehending the nature of adsorption and effectively constructing the adsorbent for use in real-world applications. Water filtering and the treatment of industrial effluents were made simple and effective by the use of V-MOF adsorbent technology. The results indicated that 383.6 mg/g was the maximal adsorption capacity at pH = 6. To evaluate the renewal of the adsorbent, more tests were carried out, and the outcomes showed that the renewal continued even after more than six cycles. The stability of the adsorbent during regeneration was confirmed by using XRD and FT-IR. The Box Behnken design (BBD) was then employed to optimize the adsorption outcomes.

Investigating the efficacy of Palladium Doped Ceria for the Photodegradation of Azo Dyes

Ceria (CeO2) was prepared by microwave assisted precipitation method while sonothermal method was utilized for the synthesis of palladium doped ceria (Pd-CeO2) photocatalyst. HR-TEM analysis confirms the face centered cubic geometry (FCC) of CeO2. The particle size of Pd-CeO2 calculated from HR-TEM analysis (7.6±2.18 nm) is in close relation with XRD (8.25±0.25 nm). The SAED pattern of Pd-CeO2 shows the poly crystallinity where the d-spacing was 0.31 and 0.30 nm which corresponds to CeO2 and Pd crystal facets 111 and 100 respectively. The amount of dopant and existence of Pd, Ce and O was confirmed from EDX spectra and elemental mapping. BET surface area analysis of CeO2 (64.45 m2/g), Pd-CeO2 (60.20 m²/g) revealed that the decrease in the surface area of CeO2 due to Pd loading which is confirmed by pore volume (0.079 cm³/g) for CeO2 and pore volume for Pd-CeO2 (0.073 cm³/g). The photocatalytic activity of Pd-CeO2 was screened against a model azo dye Acid red-4 (AR-4). The fluctuation of the rate of photodegradation (PD) of AR-4 was observed under different reaction conditions. Therefore, the reaction parameters were optimized to achieve best catalytic activity up to PD; 98%. The kinetic study suggests that the PD of AR-4 follows 1st order kinetics with regression coefficient (R2=0.973) and rate constant (k=0.024/min). Recycling study revealed the prolong use of catalyst without significant loss of activity. DFT study and experiments revealed the synergism of Pd on the photo response of CeO2. Perhaps this synergistic effect due to metal support interaction, causes redistribution of charges and Fermi energy levels. The synthesized catalyst showed potential application for the treatment of textile industrial effluents.

Polymer-grafted silica based hybrid macrobeads for Pb(II) and Cr(VI) removal from water

The presence of heavy metals in water deters its usability for drinking purposes. Indiscriminate disposal of industrial effluent into water bodies further complicates the situation. Accordingly, there is a dire need for a treatment system that can effectively remove the contaminants from water. Although there are solutions like the utilization of membrane and other powder-based adsorbers, challenges like high cost, fouling, scaling, the generation of a new class of waste (post usage), and limited recyclability often limit their usage. Hence, there is a critical need to develop a system that demonstrates high adsorption capacity, is reusable, and is easy to develop. Accordingly, we synthesized silylated polyethyleneimine, grafted it onto silica particles, and tested its efficacy in removing heavy metal contaminants like lead and hexavalent chromium from water. The resultant modified polyethyleneimine modified silica particles (termed as SiEP) outperformed many adsorber materials, including metal–organic framework, zeolite, clay, etc., and it demonstrated a staggering adsorption capacity (Langmuir) of 442 mg/g (pH 6) and 182 mg/g (pH 5) for lead and chromium, respectively at 30 °C. The developed nanopowder was further encapsulated inside polyacrylonitrile macrobeads and tested for its efficacy. Although the encapsulation resulted in a decrease in adsorption capabilities, common problems like high-pressure build-up and inefficient contact associated with powder-based adsorber were avoided upon encapsulation. The macrobeads exhibited 37 mg/g and 20 mg/g adsorption capacities for lead and chromium, respectively. For both the powder and the macrobeads, the adsorption capacity was tested in the presence of mixed ions and both the adsorber demonstrated their unique capability to be selective against targeted ions. They were further tested against a real groundwater matrix synthetically spiked with lead and chromium. Such findings open up a new avenue to developing water treatment materials that demonstrate selectivity and recyclability, indicating their potential for large-scale water treatment applications in industrial settings.

Novel synthesis and application of zeolite-Y from waste clay for efficient CO2 capture and water purification

In the present study, the microwave-assisted hydrothermal method using sodium hydroxide (NaOH) has been used to synthesise zeolite-Y from three different waste clays (WC) from Teesside, Northeast of England, UK. The effects of microwave time intervals and WC type were investigated to produce crystalline zeolite-Y. All WCs and synthesised zeolites were characterised by scanning electron microscopy (SEM), X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and Brunauer–Emmett–Teller surface area measurement (BET). The characterisation results showed that the zeolite-Y samples synthesised at 6 min intervals exhibited larger total pore volumes, higher surface areas, and higher crystallinity compared to the samples synthesised at 4 min intervals. Especially, the synthesised zeolite-Y from Clay 1 displayed high CO2 adsorption capacity, achieving 5.23 mmol/g at 298 K and 1 bar, with a maximum methylene blue removal of 94.3 %. This sample showed a surface area of 485 m²/g and a pore volume of 0.24 cm³/g, alongside an Si/Al ratio of 3.7, highlighting its excellent thermal stability at elevated temperatures. The high CO2 adsorption capacity combined with the high methylene blue removal efficacy makes the synthesised zeolite-Y from WC an excellent candidate for efficient CO2 capture and removal of methylene blue from contaminated water. Additionally, this study illustrates the potential for waste valorisation through the conversion of low-value WC into high-performance, value-added materials. This transformation not only mitigates waste disposal issues but also contributes to sustainable resource management and environmental protection by offering a practical solution for treating industrial effluents and gas emissions.

Development and performance of microalgae-based symbiotic systems for high-strength chemical oxygen demand wastewater treatment from the sugar mills

Agricultural and agro-industrial activities have risen exponentially to meet the ever-growing demand for food, energy, and other important resources. High freshwater consumption occurs in these sectors and is discharged as effluent containing excessive organic loads that require treatment. In this study, microalgal, bacterial, and fungal (yeast) isolates native to the sugar industry effluent were screened for effective chemical oxygen demand (COD) removal from wastewater when co-cultured. The microalgae-bacteria consortium (MBC) comprised Chlorella sorokiniana A7 and three bacterial strains including Rhodococcus sp. B009, Bacillus sp. B010, and B013; whilst the microalgae-yeast consortium (MYC) consisted of Chlorella sorokiniana A7 and Saccharomyces cerevisiae Y2. When the Chlorella sorokiniana-based symbiotic systems were characterized in sugar industry wastewater, excellent COD removal efficiencies were achieved compared to the axenic Chlorella sorokiniana A7. The COD removal efficiencies were 86 %, and 71 % after 96 h of cultivation for MBC, and MYC, respectively. After 168 h of cultivation in wastewater, ≥90 % of COD removal efficiency was observed in both MBC and MYC systems. The MYC also showed improved chlorophyll-a content, photosynthesis, and respiration in Chlorella sorokiniana A7. This study has demonstrated the efficiency of Chlorella sorokiniana-based consortium systems that could be used as eco-friendly and sustainable bioremediation tools for high-strength COD wastewater streams. An insight into mechanisms of interactions between Chlorella sp., and co-cultured microbial strains grown in sugar industry wastewater still needs further studies.

Kinetics of the decomposition of reactive black 5 on carbon nanostructured adsorbents

Textile industry effluents, containing vast quantities of toxic organic pollutants and synthetic dyes like Reactive Black 5 (RB5), pose a significant environmental threat. RB5 contamination can harm ecosystems and human health, necessitating effective treatment for water recycling and compliance with quality standards. Traditional methods like filtration often fall short in removing dye chemicals. This study examines the efficiency of nanocarbon-based adsorbents in removing RB5 from textile industry effluents. RB5 solutions at concentrations of 10 µM, 30 µM, 60 µM and 100 µM were investigated and characterized using scanning electron microscopy (SEM) and UV-Vis spectrophotometry. Activated carbon (AC) demonstrated the highest degree of RB5 decomposition, outperforming graphene nanoplatelets (GNPs) and graphene oxide (GO) and offering a promising solution for mitigating textile wastewater pollution. Kinetic studies revealed that RB5 adsorption follows a pseudo-second-order model for all adsorbents. The rate constants were determined using PSO kinetics and they were comparable with the rate constants of prior studies, indicating the applicability of the model to the study of the kinetics of similar dye adsorption and decomposition processes.

Industrial Pollution in Patna City : Physico-Chemical Analysis of Effluents and Their Effects on Water and Soil

Industrial pollution is a significant concern in Patna City, with rapid urbanization and industrial growth contributing to the degradation of natural resources. This study focuses on the physico-chemical analysis of industrial effluents and their effects on the water and soil quality in and around Patna. Effluents from various industries, including textile, sugar, rice mills, and small-scale manufacturing units, are released into nearby water bodies and soils, posing serious environmental risks. The research aims to assess the levels of pollutants by analysing key physico-chemical parameters such as pH, total dissolved solids (TDS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), heavy metals (lead, chromium, cadmium), and organic contaminants in industrial effluents. Samples were collected from various locations near industrial zones and water bodies. The study also evaluated the impact of these pollutants on soil and groundwater quality. It was found that prolonged exposure to industrial effluents led to the accumulation of toxic metals in soil, reducing its fertility and altering its structure. Additionally, groundwater sources were contaminated with hazardous chemicals, making them unfit for drinking and irrigation purposes. The implementation of advanced treatment technologies and sustainable industrial practices is crucial for safeguarding the environment and public health in Patna City.