Industrial Wastewater Research Articles

Efficient biodecolorization of direct black 22 Azo Dye by Aspergillus tamarii Kita UCP1279 isolated from caatinga soil

The textile industry is a major consumer of water, generating large volumes of wastewater contaminated with harmful substances, particularly azo dyes, which contain aromatic rings, amines, and sulfonic groups that contribute to their environmental toxicity. The use of microbial agents for wastewater treatment offers a cost-effective and sustainable solution, minimizing sludge production. Fungi from the Caatinga biome have demonstrated potential for bioremediation, especially under extreme environmental conditions. This study explores the ability of Aspergillus tamarii Kita to decolorize the azo dye Direct Black 22 (DB22) under varying conditions, including the use of both active and inactive fungal biomass, in static and agitated systems (120 rpm), at a controlled temperature of 30°C. Dye concentrations of 50, 125, and 250 mg/L were evaluated over time intervals of 75, 180, and 180 minutes, respectively. The influence of dissolved oxygen concentration and redox potential on the decolorization process was also investigated to identify optimal treatment conditions. Decolorization efficiency was quantified via spectrophotometric analysis. Results revealed decolorization rates of 100%, 97%, and 63% for the respective dye concentrations, with active biomass in agitated conditions achieving the highest removal rates. The study further demonstrated that dissolved oxygen levels and redox potential are critical factors in enhancing dye decolorization. These findings underscore the bioremediation potential of Aspergillus tamarii Kita in treating textile dye effluents, offering a promising approach to sustainable industrial wastewater management.

Innovative synthesis of ternary heterojunction CuInS2/BiOI/Bi2MoO6 for 2,4-DCP degradation and its dechlorination performance

This study focuses on a novel ternary heterojunction catalyst for the removal of 2,4-dichlorophenol (2,4-DCP), an organic pollutant that is difficult to degrade. An efficient CuInS2/BiOI/Bi2MoO6 ternary heterojunction photocatalyst was formed by constructing a CuInS2/BiOI composite layer on a Bi2MoO6 substrate using an in-situ growth technique. The microstructure and photoelectric conversion properties of the catalysts were comprehensively resolved by systematic material characterization, including scanning electron microscopy (SEM) observation, X-ray photoelectron spectroscopy (XPS) analysis and photoelectrochemical testing. The experimental results showed that the optimized catalyst at a loading of 2.0 g/L exhibited excellent photocatalytic degradation efficiency against 20 mg/L concentration of 2,4-DCP at neutral pH, reaching 80.3 % degradation rate in 120 min. This high performance was mainly attributed to the enhanced charge-carrier separation mechanism at the heterojunction interface, which effectively enhanced the utilization and transfer rate of photogenerated electron-hole pairs and enhanced the photocatalytic activity of the catalyst. In addition, the study also deeply explored the conversion pathway of elemental chlorine in the photocatalytic system, elucidated the mechanism of 2,4-DCP degradation and dechlorination, and provided a theoretical basis for further improving the environmental adaptability and dechlorination efficiency of the catalyst. Overall, the CuInS2/BiOI/Bi2MoO6 ternary heterojunction photocatalysts proposed in this study demonstrate a broad application prospect in the purification of 2,4-DCP and other organic pollutants, and open up a new way to solve the problems of industrial wastewater treatment, which is of great environmental significance and scientific value.

Electrocoagulation Treatment of Wastewater Collected from Haldia Industrial Region: Performance Evaluation and Comparison of Process Optimization

This study investigates the treatment of oil-contaminated wastewater with high levels of inorganic substances, suspended solids and turbidity, collected from the Haldia industrial region of India in February 2023. The wastewater, originating from industries such as chemical, petrochemical, textile, and battery manufacturing, presents a complex pollutant load that challenges traditional treatment methods. Electrocoagulation was employed as the treatment technique, with process optimization conducted using Box-Behnken design (BBD) and central composite design (CCD) for key parameters: pH, initial oil concentration, current density, and electrolysis time. The study comprehensively examined the effects of these parameters on turbidity removal. The optimal conditions were determined to be a pH of 7.5, an initial oil concentration of 275 mg/L, a current density of 17.5 mA/cm², and an electrolysis time of 20 min. Under these conditions, CCD outperformed BBD, achieving a desirability score of 93% compared to 80% for BBD. The process successfully reduced turbidity from 450 NTU to 56 NTU and total suspended solids (TSS) from 300 mg/L to 102 mg/L. The operation cost of the process was found to range from ₹0.904/m³ to ₹2.71/m³ as the electrolysis time increased from 0.17 to 0.5 h. The study presents a viable solution for industrial wastewater treatment in this region, aligning with the United Nations Sustainable Development Goal (UN SDG) 2030. Additionally, combining electrocoagulation with membrane filtration may enhance comprehensive pollutant removal.

Current regulates electron donors for heterotrophic and autotrophic microorganisms to enhance sulfate reduction in three-dimensional electrode biofilm reactors

The variability in industrial production often generates wastewater with an unstable carbon-to-sulfur ratio, challenging the concurrent removal of sulfate and organic compounds. Three-dimensional biofilm electrode reactor (3D-BER) technology offers a promising solution, compatible with both autotrophic and heterotrophic sulfate reduction. In this study, four up-flow 3D-BERs with gradient current levels were operated for nearly 400 days to treat simulated high-concentration sulfate wastewater. The effects of current intensity, hydraulic retention time (HRT), and influent carbon-to-sulfur ratio on sulfate and organic removal were investigated. The composition and functions of microbial communities were analyzed by metagenomic sequencing. The synergistic mechanism between heterotrophic and autotrophic sulfate reduction was examined by delineating their individual contributions to sulfate removal. Under optimized conditions (HRT 60 h, influent carbon-to-sulfur ratio of 1.7, and current intensity of 50 mA), the highest removal efficiencies for SO42- and COD reached 70.47 % and 85.58 %, respectively. Elevated current intensity increased the abundances of Desulfuromonadaceae, Desulfovibrionaceae and Methanobacteriaceae, while decreasing Anaerolineaceae and Geobacteraceae. Key genes involved in carbon fixation and hydrogen-relied sulfate reduction showed lower abundances at high current levels, whereas genes for direct electron uptake from the electrode were more abundant. Batch experiments demonstrated a synergistic effect between autotrophic and heterotrophic sulfate reduction, most pronounced at 50 mA. Our work successfully regulates electron donors for microbial reduction of high-concentration sulfate in 3D-BERs by manipulating current intensity, providing new insights into the application of bioelectrochemical technology for complex industrial wastewater treatment.

Unveiling Taro's (Colocasia esculenta) potential as a source of antioxidants and nutritional elements: Industrial impact on quantitative risk assessment of potentially toxic metals accumulation

With rapid industrialization and urbanization, persistent potential toxic elements in the human food chain have become a burning concern to international communities. The present study investigates the potential of an underutilized orphan root crop, Taro (Colocasia esculenta), as a possible source of bioactive compounds –phenolics (180.56-17.66 mg GAE/100g sample) and flavonoids (50.37-21.93 mg QE/100 g sample)–, antioxidants and minerals (Mg: 183.33-75, P: 203-73, Ca: 740-46 and Na: 393-133.33 mg/kg) to promote its utilization in food industries. In addition, this study estimated the levels of potential toxic metals in corm samples collected from industrially active: Jute industry sites (JTS), Textile sites (TXS), Tannery sites (TNS), Chemical industry sites (CMS), Feed industry sites (FDS), and inactive: Residential site (RDS) regions of Jashore, Bangladesh and assessed the associated human health risks. ICP-OES was used to analyze the samples, and the probable human health risk was evaluated using the estimated Hazard Index (HI) and Lifetime cancer risk (LcR). The concentration of the studied toxic metals, such as Cr, Cd, and Pb, and potentially toxic metals, such as Zn, Ni, Fe, Cu, and Mn, ranged as 1.8-19.33, ND, ND-6.33, 3.23-146.67, ND-29.16, 5.43-3583.33, 4.43-266.67, and 0.45-7.3 in taro corm samples and 2.76-42.33, ND-1.26, ND-153.33, 3.27-163.33, 32.67-55.67, 436.67-7666.67, 1.47-9.47, and 4.16-213.33 mg/kg, respectively, in the associated soil samples. HI values greater than unity in RDS, JTS, FDS, TNS, and CMS indicated the associated non-carcinogenic risk to adults. In addition, LcR showed that all the samples pose an associated cancer risk. Furthermore, multivariate analysis revealed three principal components explaining 86.69 % of the total variance, while there were two significant clusters of the taro samples. Overall, this study demonstrated the potential of taro corms as a valuable source of advantageous phytochemicals while confirming the effect of industrialization on the accumulation of potentially toxic metals and their phytochemicals. This study underscores the necessity of continuous monitoring by regulatory authorities to prevent metal deposition in farmlands from industrialization and urbanization through sewage, agrochemicals, and industrial wastewater to avoid adverse health consequences.

Study on PPTA/PEMs/PA composite NF membranes for highly efficient desalination of high-saline Kevlar® brine and long-term anti-scaling performance

It produces a large number of organic brine during the polymerization process of Kevlar®, which contains N-(1-Methyl-2-pyrrolidinone) (NMP) and high concentrations of CaCl2 and NaCl. The wastewater will cause serious pollution of water and soil resources if discharged directly. The separation and recycling of inorganic salts have been an industrial difficulty. In this paper, based on the novel concept of green self-recycling, we used Poly (p-phenylene terephthamide) (PPTA, resin of Kevlar®) ultrafiltration membrane as the substrate, composited the loose and curled polyelectrolyte multilayers (PEMs) as interlayers and formed a homogeneous polyamide separation layer through interfacial polymerization, from which we obtained the homogeneous reinforcement aramid composite nanofiltration (NF) membrane. The composite NF membranes with different interlayer numbers showed different advantages. For single-component brine, the retentions of PEMs-1/PA membrane were 93 % and 98.4 % for 10 g/L CaCl2 and MgSO4 respectively. For mixed brine of 20 g/L CaCl2 and NaCl, the retentions of PEMs-3/PA membrane were 87.13 % and 1.05 % for CaCl2 and NaCl respectively with the separation factor as high as 82.95. In the test of long-term service stability, PEMs-3/PA maintained stable performance in 4 cycles total of 160 h. And the permeance could almost fully recover after pure water backwash of only 0.5 h. In addition, the structural stability and anti-scaling performance of the PEMs-3/PA membrane were further verified in high-temperature brine. Surprisingly, the obtained PPTA NF membrane in this work could effectively treat the high-saline brine in the Kevlar® polymerization process and would have more promising prospects in the treatment of industrial wastewater of brine.

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.

Machine learning-assisted source tracing in domestic-industrial wastewater: A fluorescence information-based approach

An emergency water pollution incident poses a significant risk to the proper functioning of wastewater treatment plants, particularly in domestic-industrial integrated facilities. Source tracing is recognized as an effective method to mitigate ongoing impacts. Machine learning-assisted traceability is emerging as a more efficient and faster method compared to traditional methods. In this study, a total of 712 sets of characterization wastewater information from effluent samples from14 discharge enterprises across 6 different sectors, as well as domestic wastewater was collected using 3-dimensional fluorescence spectroscopy. After data cleaning and augmentation, a feature fingerprint database of wastewater was constructed to train a traceability model. Several machine learning algorithms, including Back Propagation neural network (BP), Random Forest (RF), Support Vector Machine (SVM), Naive Bayes (NB) and K-Nearest Neighbors (KNN), were selected for constructing the traceability framework. Subsequently, an advanced Particle Swarm Optimization Random Forest model (PSO-RF), capable of automatically optimizing model parameters, was proposed and applied to trace the sources of wastewater in integrated wastewater treatment plant. The PSO-RF achieved and accuracy of 96.55 % in sector identification and 94.25 % in manufacturer identification. As part of the validation process, laboratory simulations were conducted using blended wastewater with different volume ratios of domestic and industrial wastewater to evaluated the potential application of PSO-RF. The results consistently demonstrated PSO-RF's effectiveness, particularly in tracing pharmaceutical wastewater sources, maintaining an accuracy of over 85 %. This work presents a novel strategy for tracing abnormal sources during emergency pollutant incidents, providing essential support for integrating artificial intelligence (AI) into meticulous wastewater management.

Mussel-inspired co-deposition of catechol-amine and graphene oxide (GO) modified anion exchange membranes (AEMs) for antifouling

Mussel-inspired co-deposition has many applications in surface modification of polymer membranes. Organic fouling of ion exchange membranes is one of the common issues that hinder electrodialysis treatment of industrial wastewater. In this work, anion exchange membranes were surface-modified by the mussel-inspired co-deposition of catechol-amine and graphene oxide (GO) nanosheets. Results showed that co-deposition with catechol (CA) and m-phenylenediamine (MPD) as reactant monomers rapidly generated modifying layer on the AEM surface. And the addition of GO into co-deposition helped improve the homogeneity and reduce polymer particle aggregation. The synergistic effect of catechol-amine and GO nanosheets was beneficial to form uniform modifying layer with improved hydrophilicity and negative charge density of membrane surface. In eletrodialysis experiments with sodium dodecyl benzene sulfonate (SDBS) as model foulants, GO-CA-MPD-3h modified AEM maintained high desalination rate close to that without folants, indicating good modifying antifouling performance. Mussel-inspired co-deposition of catecholamines and functional materials give new insights into membrane modificatin through a feasible and cost-effective method

Pressure Monitoring of Disposal Reservoirs in North‐Central Oklahoma: Implications for Seismicity and Geostorage

AbstractDisposal of industrial wastewater and activities such as underground sequestration depend upon pressure conditions within deep geologic reservoirs. Sometimes, injection and storage are associated with induced seismicity, suggested to result from reservoir compartmentalization, leakage into faults, or other mechanisms in the subsurface. To understand subsurface pressure conditions within a major regional disposal reservoir, the Arbuckle Group of Oklahoma, we monitored the water levels in 15 inactive injection wells. The wells were monitored at 30‐s intervals, with eight wells monitored since September 2016, and an additional seven from July 2017. All the wells were monitored until early March 2020. Since 2016, hydraulic head decreased in 13 of the 15 wells, proportional to near‐borehole fluid pressure even considering decreasing regional injection volumes during this period. The well pressures respond to three types of perturbations: (i) gravitational fluctuations (a.k.a. solid‐earth tides) (ii) distal and proximal earthquakes, and (iii) injections into nearby wells. Parameterization of tidal responses illustrates that the near wellbore environments have negative fluid flux (i.e., are leaking). Earthquakes cause differing pressure responses from well to well, with some highly sensitive to proximal events, some to distal events, and some apparently insensitive. Injections have variable impacts in some cases masking tidal and earthquake pressure signals. Collectively, there appears to be a threshold injection rate above which well pressure becomes less sensitive to the volume of injections within 15 km. Multi‐scale geological structure and temporal permeability changes are likely controlling the pressure field, indicating leakage of fluids across the system.

Coupling adsorption and in-situ Fenton-like oxidation by iron-containing low-grade attapulgite clay towards organic pollutant removal: From batch experiment to continuous operation

Coupling adsorption and in-situ Fenton-like oxidation process was developed for Methylene blue (MB) using refined iron-containing low-grade attapulgite (ATP) clay, and the removal mechanism was investigated. The MB was initially adsorbed on the porous ATPs, and then the enriched MB was removed by the H2O2-assisted Fenton-like oxidation with the iron-containing ATP catalyst. Under optimal conditions, the ATP powder exhibits the maximum removal efficiency of 100% with negligible iron leaching (1.5 mg L-1) and no sludge formation. Furthermore, polysulfone/ATP (PSF/ATP) pellets were fabricated through a water-induced phase separation process to construct a fixed-bed reactor (FBR) for continuous contaminant removal. For the first cycle, the maximum adsorption capacity was 15.5 L with an outlet MB concentration of 1.973 mg L-1 (˂ 2 mg L-1, GB4287-2012) using the PSF/ATP pellets containing 50.0 g of ATP powders, and the maximum Fenton-like oxidation capacity was 35.5 L with the outlet concentration of 0.831 mg L-1. After five cycles, the total treated volume of the MB solution was ca. 255 L, and the efficiency remained above 99%. After 10 hours of continuous treatment towards practical resin industrial wastewater, the chemical oxygen demand (COD) removal efficiency was still measured at 83.05%, costing 0.398 $ m-3. These results demonstrate the practical applicability of iron-containing low-grade ATP clay for textile water treatment.

CsPbBr3 perovskite nanocrystals-based portable testing device for on-site detection of chloride ions from wastewater

The detrimental effects of chloride (Cl−) ions on industrial wastewater necessitate the in-situ monitoring of Cl−, which is challenging due to the limited availability of field-applicable analytical methodologies. Herein, a novel and compact apparatus (CPB-FC-Cl) was developed for the precise quantification of Cl− in wastewater. This innovative system utilizes the rapid halide exchange of cesium lead bromide (CsPbBr3) perovskite nanocrystals (NCs) with Cl−, a process marked by a pronounced wavelength blueshift and a vivid fluorescence transition from green to blue. The software in the CPB-FC-Cl system automatically identified the fluorescence emission peaks and displayed the Cl− concentration values on the user interface. The detection experiments conducted on actual hydrochloric acid wastewater confirmed the device’s ability to accurately measure Cl− concentrations within 5 min, achieving an accuracy of 98.98 %. The CPB-FC-Cl system exhibited high selectivity in the presence of various coexisting substances in hydrochloric acid wastewater, and its resistance to potential interferences supports its suitability for precise Cl− quantification. The stability of the CPB-FC-Cl system showed an average detection accuracy of 98.96 % over multiple cycles, which underscores its robustness for long-term monitoring applications.

Chloride-Salt Separation Type Nanofiltration Membranes for Efficient Crude Salt Refinement

Application of unrefined crude salt not only leads to a serious equipment scaling and a low product quality, but also increases operational risks and poses health hazards. Therefore, it is essential to refine crude salt prior to its use. However, traditional methods of crude salt refinement are energy-intensive and probably produce additional chemical by-products. In this work, membrane technology was used to accomplish the refinement of crude salt due to its unique characteristics, such as environmentally friendly and lower energy consumption. To improve the separation performance, the membranes were fabricated by simply adjusting the aqueous monomer concentration. For single-salt feed, the membrane (M10) prepared with a high ratio of 10 exhibited excellent salt rejection due to the formation of a thicker and denser PA layer. And it owned a superior MgCl2/NaCl selectivity of ∼22.0, demonstrating that the membrane can achieve outstanding selectivity for mono-/divalent ions. The selectivity of Mg2+/Na+ increased to ∼23.5 for bi-salt feed and further improved to 66.2 for multi-salt feed due to the stronger charge shielding effect. Most importantly, the membrane was also successfully applied in the refinement of crude salt. When using crude salt (NaCl 30 g/L, purity 0.90) as feed, the M10 exhibited both excellent retention of bivalent ions and permeation of univalent ions, resulting in the corresponding Mg2+/Na+ selectivity up to ∼251.6 and the tremendous enhancement in the Na+ purity of ∼0.997. This work offers a feasible strategy for crude salt refinement, and could expand to some other potential applications such as resource utilization in the salinization industry and zero-liquid discharge of industrial wastewater.

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.

Colour and COD Removal from Food and Beverages Industrial Wastewater by using Spent Alkalis Carbide Lime (SACL)

The abundant amount of water used in the food & beverages (F&B) industry has caused the wastewater from this industry to be one of the major sources of water pollution, due to its high content of colour and chemical oxygen demand (COD). In this study, spent alkalis carbide lime (SACL) was used in treating the colour and COD simultaneously from the F&B industrial wastewater. SACL was used to reduce the amount of landfill waste and because of its similar characteristic to lime. The SACL was characterized using X-ray Diffractometer (XRD) X-ray Fluorescence (XRF), Scanning Electron Microscope (SEM), and Fourier-Transform Infrared Spectroscopy (FTIR) while the F&B industrial wastewater was characterized by using HACH DR6000 and UV-Vis Spectrophotometers. Several series of chemical precipitation experiments were conducted through jar tests to evaluate the effects of SACL dosing, pH value, and contact time on the percentage removal of colour and COD. The optimum conditions obtained from this study are pH 7 and 20 minutes, with percentage removal of 99.5% and 89.8% for colour and COD. However, the percentage removal of colour and COD decreased as contact time increased. With the same value of pH and contact time, SACL managed to remove more colours compared to lime, which is 93.6% compared to 88.54%, respectively. According to the analyses of FTIR and UV-Vis, the wastewater sample was cleaner when using SACL compared to using lime during the treatment. Thus, the study proves that SACL is a reliable alternative to treat colour and COD from F&B industrial wastewater.

Detection of Essential Trace Element of Chromium by Electroanalytical Methods

A detailed study of essential ultra trace element of chromium present many of industrial waste lakes of western rajasthan. Aconvinent method of electroanlytical technique used for the essential trace element present in the industrial waste water as a polarography method for identification of essential trace element by using concentration of ppm to ppb. According to this method prepare solution of sodium chromate as a stock and identify electroanalytical potential by using as a supporting electrolyte 0.05 M HCl + 0.25 M NaCl give a sharp peak at ࡱ૚ ૛ ൗ = 0.91(V) and result compare with other electroanalytical instrument like UV-Vis Sprctrophotometer, Atomic absorption spectroscopy

STUDY OF THE BEHAVIOR OF ARSENIC IN COPPER ELECTROLYTE

Abstract. In industrial wastewater, arsenic is most often present in the trivalent state. An analysis of existing purification methods shows that in all cases, with a few exceptions, the most complete removal of arsenic is observed from solutions in which it is in the pentavalent state. This is explained by the significantly lower solubility of arsenates of heavy and alkaline earth metals compared to the corresponding arsenites. The chemical oxidation of As(III) in the following systems was studied: As(III)-H2SO4-H2O, As(III)-MeSO4-H2O, As(III)–H2SO4–MeSO4–H2O (where Me is Cu, Ni, Co, Mn, Zn). The influence of temperature, the amount of transition metal ions, the duration of the experiment, and the concentration of sulfuric acid on the degree of transition of As(III) to As(V) was studied. The effect of catalytic oxidation of As(III) in sulfuric acid solutions was discovered. The maximum degree of oxidation of trivalent arsenic (55-60%) is observed when transition metal salts are introduced into an arsenic solution in the presence of a platinum plate. It has been established that the nature of the studied transition metal salts (Cu2+, Ni2+, Co2+, Mn2+, Zn2+), process duration and temperature do not have a significant effect on the degree of As(III) conversion. The results obtained largely explain the predominance of pentavalent forms of arsenic in production solutions of non-ferrous metallurgy. Key words: copper electrolyte, arsenic, transition metals, catalytic role, instant oxidation effect, activated oxygen.

Industrial wastewater treatment from oil and petroleum products with carbonate sludge

In the modern world, pollution of industrial wastewater by oil and petroleum products is one of the most acute environmental problems. These pollutants have a significant negative impact on ecosystems and water quality. In this regard, there is a need to develop effective and environmentally safe methods of wastewater treatment. The aim of the study is to develop and evaluate the efficiency of using carbonate sludge as an adsorbent for removing oil and petroleum products from wastewater. The scientific and practical significance of the work lies in the proposal of an environmentally friendly treatment method that can not only improve the quality of wastewater, but also ensure the disposal of industrial waste. The use of carbonate sludge, a by-product of industry, makes the method cost-effective and reduces the environmental burden. The main results of the study showed that carbonate sludge has a high sorption capacity for petroleum products. The adsorption isotherm belongs to type I according to the Brunauer, Deming, Deming and Teller classification, which indicates the presence of monolayer adsorption on the sludge surface. It was found that the sludge is able to remove up to 95% of pollutants from wastewater. The value of the study lies in demonstrating that carbonate sludge is an effective and affordable material for solving environmental problems associated with water pollution by petroleum products. This research contributes to the development of industrial waste recycling technologies by offering a newapplication for carbonate sludge. The practical significance of this work lies in the possibility of introducing this method at industrial enterprises for wastewater treatment, which can lead to a reduction in waste disposal costs and an improvement in the environmental situation. The results of the study can be useful for enterprises of the petrochemical industry and wastewater treatment plants.

Application and Research Progress of Biochar in Environment Pollution Control

Biochar is a carbon-rich material with a wide range of raw materials, low cost, and environmental friendliness. It has a range of advantages such as high porosity and rich surface functional groups. Recently, the application of biochar to control environmental pollution and to improve soil quality have become increasingly widespread. To systematically summarize the application status, efficiency, shortage and development prospects of biochar in environmental pollution control, this article concludes the viewpoints from resent research of biochar materials in marine oil, soil pollution control and industrial wastewater, and made the prospect of biochar materials application in the environmental pollution control and remediation.

Adaptive Active Site Turning for Superior OER and UOR on Ir‐Ni3N Catalyst

AbstractRenewable energy‐based electrocatalytic oxidation for hydrogen production in complex reaction environments such as industrial wastewater and human urine demands high‐performing catalysts to conduct switchable urea oxidation reactions (UOR) and traditional oxygen evolution reactions (OER). Here, a novel bifunctional nanosheet electrocatalyst is reported, Ir‐Ni3N, which exhibits excellent electrocatalytic activity for both OER and UOR under alkaline conditions. Specifically, the overpotentials at 100 mA cm−2 for OER and UOR are 1.59 and 1.37 V vs. reversible hydrogen electrode (RHE) respectively, which are superior to most of the recently reported nickel‐based catalysts. Accordingly, a comprehensive mechanism for competitive catalytic activities of Ni and Ir sites in Ir‐Ni3N and the switch between OER and UOR that guarantees consistent hydrogen production is proposed. This study provides a feasible strategy for continuous hydrogen production aided by reagent‐adaptive electrocatalysts in urea‐containing wastewater.