The escalating contamination of water resources by heavy metals, bicarbonates, seawater, and drain-wastewater intrusion is a multifaceted challenge, necessitating sustainable remediation strategies. A multi-objective bioremediation approach that acclimatizes and utilizes microalgae to mitigate pollutants concurrently is adopted. Twelve microalgae were acclimatized to heavy metals (copper, cadmium, and chromium) up to 100 mg/L, salinity similar to seawater up to 50% v/v, elevated bicarbonate levels up to 40.78 g/L, and drain-wastewater up to 50% v/v, simultaneously (sample not from an actual plant). This was carried out in batches using modified-Zarrouk's medium added with heavy metals, seawater, bicarbonate, and wastewater, with a four-step increment to reach the above concentrations and slowly acclimatize during microalgae cultivation and bioremediation. Bicarbonate in the medium was intermittently added with 3 g/L increments, gradually escalating to 13.5 g/L over a 15-day batch. Other operational conditions for mixotrophic microalgae cultivation were: illumination- red (680 nm, 45000 lx); initial sugar- 5.5 g/L; initial pH- 9.2; and temperature- 28 ± 2 °C. The microalgae demonstrated a synergistic capacity for multi-contaminant removal and production of value-added byproducts, achieving removal efficiencies exceeding 90% for heavy metals, a 100% reduction in bicarbonate levels, and a marked decrease in salinity. Lipids from Nannochloropsis sp., Arthrospira platensis, Scenedesmus obliquus, Chlorella vulgaris, Chlorococcum sp., and Navicula sp. 2 produced 3rd-generation quality biodiesel via transesterification, with high fatty acid methyl ester content and viscosity as per ASTM-D6751 standard. Eco-friendly wastewater treatment technology developed showed high bioremediation efficiency and also provided alternative energy as a sustainable solution, supporting UN-SDGs 6 and 7.

The rapid expansion of industrial activity has significantly increased sludge generation from wastewater treatment plants. Slaughterhouse sludge poses serious treatment challenges due to its high organic load, pathogenic microorganisms, and complex pollutant profile. The present work evaluates ultrasonic pretreatment as a strategy to enhance the anaerobic digestion (AD) of slaughterhouse sludge, using soluble chemical oxygen demand (sCOD) as an indicator of biogas production potential. A central composite design under response surface methodology (RSM) was employed to study the effects of ultrasonication power (223–650 W) and exposure time (13–52 min) on sCOD solubilization. The maximum sCOD of 9090 mg/L was achieved at 650 W and 32.5 min, indicating a notable enhancement in solubilization efficiency. Analysis of variance (ANOVA) confirmed the model’s robustness (R2 = 0.976), with ultrasound power exerting a stronger influence than exposure time. The ultrasonic pretreatment with RSM optimized conditions increased specific biogas yield by 7.15-fold during the AD process, compared to untreated sludge. The composition of biogas (especially methane) also improved due to ultrasound pre-treatment, possibly due to accelerated hydrolysis, particle size reduction, and enhanced biodegradability. The RSM findings were validated with the experimental biogas yields obtained from ultrasound-pre-treated Slaughterhouse sludge samples. Thus, the present work demonstrates ultrasonication as a promising and environmentally friendly pretreatment method, with strong potential to optimize industrial-scale biogas recovery from high-strength organic wastes such as slaughterhouse sludge.

Microalgal biorefineries are considered an extremely promising approach for achieving a circular and carbon-neutral bioeconomy by synergistically combining CO2 sequestration with wastewater utilization. The present research highlights an integrated experimental-computational framework to maximize carbon capture, utilization, and storage, along with bioremediation and the synthesis of precursors for biomass/biofuels production in the pre-acclimatized Scenedesmus obliquus. Continuous chemostat cultivations with dilution rates from 0.005 h−1 to 0.040 h−1 were operated using seawater-drain-wastewater containing externally-added heavy metals and bicarbonates. Measured extracellular fluxes, quantified with HPLC, GC–MS, and CHNS/O analyses, were used as experimental constraints in a novel genetic-algorithm metabolic-flux-analysis approach, implemented in MATLAB®. Employing a stoichiometrically balanced network of 185 reactions, the computational workflow resulted in precise measurement of intracellular carbon partitioning. The carbon was directed towards overflow metabolism at the low dilution rate, resulting in acetate (2.588C−mmol/gbiomass/h). At a high dilution rate (0.040 h−1), the co-utilization of carbon leads to the highest biomass (1.689C−mmol/gbiomass/h), a remarkable carbon capture efficiency of 98.5%, while simultaneously maximizing lipid productivity (181.15 mg/L/h). This concurrently sustained the co-production of high-value pigments, yielding intracellular productivity of 0.453 mg/L/h for ‘chlorophylla’ and 4.803 mg/L/h for phycocyanin. The steady-state at 0.025 h−1 achieved the highest heavy metal removal efficiency (reaching 99.04%, 99.17%, and 99.01% for Cu2+, Cr3+, and Cd2+, respectively). Through identifying key targets for metabolic engineering to reduce byproduct secretion while simultaneously maximizing biorefinery systems, this research presents an innovative, scalable solution that directly supports the climate-water-energy nexus and United Nations Sustainable Development Goals 6, 7, 12, and 13.

Aloe-vera Leaf Waste Magnetically Modified (AMNP) was prepared and applied as a bio-adsorbent for crystal violet (CV) dye removal from aqueous solution. The material was characterized by ultraviolet-visible spectroscopy (UV), field emission scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), Zeta potential analysis, Brunauer-Emmett-Teller surface area analysis (BET) and Vibrating sample magnetometry (VSM) confirming its porous structure, functional groups, and magnetic properties. Batch adsorption studies showed a maximum CV removal of 96.4% with a Maximum adsorption capacity of 58 +/- 5.75 mg/g at pH 8. The adsorption followed the Freundlich isotherm (R2 = 0.95), suggesting multilayer uptake, and the pseudo-second-order kinetic model (R2 = 0.99), indicating chemisorption. Thermodynamic analysis revealed the process to be spontaneous and endothermic with Delta H degrees = 11.5 +/- 0.94 kJ/mol. Desorption experiments confirmed that AMNP remained reusable over several cycles with moderate efficiency. Compared with other reported bio-adsorbents, AMNP exhibited competitive capacity, low cost, and reusability. These findings demonstrate AMNP as a sustainable and eco-friendly material for treating dye-contaminated wastewater.

This study introduces a seminal dual-phase valorization strategy for OPW, where sequential pectin extraction (6.3 % yield) and subsequent application as a biosorbent achieves 96.03 % removal efficiency of DV 35 dye, a previously understudied azo pollutant. Through Response Surface Methodology (RSM) with Central Composite Design, optimal conditions were identified as pH 2.28, 85 mg L-1 initial dye concentration, and 15.84 g L-1 OPW dose, validated by high model accuracy (R2 = 0.98, adjusted R2 = 0.96). The adsorbent demonstrated exceptional Freundlich isotherm compliance (R2 = 0.99), revealing heterogeneous multilayer adsorption with a favorable dimensionless separation factor (0.019-0.006), and achieved a monolayer capacity of 43.84 mg g-1 at 303 K, surpassing prior agricultural waste-based adsorbents. BET (30.276 m2/g surface area), SEM-EDX, and FTIR identified critical functional groups (-OH,-COOH) enabling electrostatic binding with DV 35's sulfonate groups, while pseudo-second-order kinetics (R2 = 0.99). Thermodynamic profiling revealed spontaneous (Delta G degrees =-25.02 kJ mol-1) and endothermic (Delta H degrees = 59.48 kJ mol-1) adsorption, driven by entropy (Delta S degrees = 0.29 kJ mol-1 K-1). The process exhibited dual-phase diffusion dynamics: rapid film diffusion (67 % removal within 4 min) followed by pore diffusion, with external film diffusion as the initial rate-limiting step. Present work aligned with circular economy principles by transforming waste into a high-value resource-first extracting pectin, then repurposing residues for dye remediation. This work establishes OPW as a cost-effective, eco-friendly solution for textile wastewater challenges, addressing a critical gap in azo dye adsorption research.

The method of using waste from A.barbadensis miller leaves powder as a biosorbent has shown promise in treating wastewater, there has not been much research done on magnetized biosorbent up to this extent. This study investigates the biosorption of anionic dyes Direct blue dyes-86 and Acid yellow-36 from aqueous solution by magnetic Modified A. barbadense Miller leaves derived (MMABL). The Synthesis of MMABL, physicochemical characteristics have been investigated by VSM, BET, XRD, SEM-EDX, FTIR. To study the effect of pH (1-9), Concentration (10-200 mg/l), Contact Time (10-60 min) Temperature (283-323 K), kinetics, isotherms and thermodynamics on the biosorption of dyes batch biosorption experiments were conducted. Optimum values of this conduct experiment at 100mg/l aqueous dye solution, 0.6 g of MMABL, pH 2, RPM 170, Temp 303 K, Time 40 min. The kinetic study demonstrated pseudo second order fitted well both the anionic dyes and Langmuir adsorption isotherm model best represented biosorption results with the maximum monolayer adsorption capacity of 75.18 mg/l for AY-36 and 312.5 mg/l for DB-86. According to the thermodynamics parameters biosorption process were spontaneous and favoured endothermic reaction. Regeneration and reusability of MMABL were investigated. The findings in this research are suggesting MMABL as an inexpensive biosorbent that demonstrates high efficacy for anionic dyes removal in a more realistic biosorption system.

Present study focuses on lipases from Candida rugosa fermentation using two carbon substrates (glucose and maltose) in synthetic medium and their characterization with activities against known standards, and additional application in biodiesel production from rubber seed oil to show their substrate specificity in transesterification. Synthetic medium with maltose and glucose produces the maximum lipase activities of 50,400 U/L and 11,520 U/L, respectively. The lipases loaded on SDS-PAGE are characterized with sizes 57 and 61 kDa. Specificity of produced lipase is tested, inedible rubber seed oil is biotransesterified, which exhibits high lipase specificity as acting on the long chain fatty acids (up to C25) to yield 94.6 % biodiesel. This study confirms the high potential of lipases in serving United Nations Sustainable Development Goal 7 (clean energy). Lipases transesterify saturated and unsaturated fatty acids and produce quality biodiesel assessed by its density-872 kg/m3, kinematic viscosity5.344 cS, and calorific value-9988 kcal/kg.

The objective of the present study was the biosynthesis of nonhazardous and cost-effective silver nanoparticles (AgNPs) using plant extracts of Azadirachta indica (neem), for the removal of hexavalent chromium [Cr (VI)] ions from an aqueous solution. Fourier transform infrared (FT-IR) and energy dispersive X-ray (EDX) spectroscopy characterization results confirmed successful biosynthesis and the presence of elemental silver in the AgNPs. Further, scanning electron microscopy (SEM) and particle size analysis indicated that AgNPs have an amorphous structure and are highly monodispersed. Batch adsorption studies were conducted to investigate the impact of parameters, like pH, time, and initial concentration on Cr (VI) removal efficiency at a fixed AgNP dose of 50 mg and 150 rpm. From the batch study, maximum chromium removal of 87.68% was achieved at an initial concentration of 5 mg/L, pH of 1, and time of 50 min. Results from equilibrium and kinetic study indicated pseudo-second-order reactions kinetics with monolayer coverage. The maximum adsorption capacity of 7.2 mg/g was obtained at an equilibrium time of 50 min and temperature of 30 degrees C. These synthesized AgNPs also displayed significant antibacterial activity against both Gram-positive Bacillus subtilis and Gram-negative Escherichia coli. Based on the results obtained, biosynthesized AgNPs from extracts of A. indica could be utilized for the removal of water pollutants.

The present study elaborates the electrocoagulation process for the removal of nitrates from synthetic and real groundwater. Electrocoagulation treatment has a positive effect on the quality of groundwater in general and the removal of nitrate in particular, which is one of the most potent pollutants found in groundwater. Moreover, it is supposed that nitrate removal mechanisms are likely to be dependent on operational parameters like applied current, electrode material, initial concentration of nitrates, and pH of the solution, etc. Therefore, in the present study various process parameters have been optimised in terms of nitrate removal efficiency. Experiments were performed using batch process at different initial concentration of nitrates (100-500 mg/L), pH (6.0-12), stirring speed (100-500 rpm), inter-electrode distance (0.5-2 cm) and electrolysis time (30-180 min). Further, the effect of co-existing ions using KNO3, Ca(NO3)(2) and Mg(NO3)(2) in the presence of NaCl and Na2SO4 was investigated. Maximum 98%, Nitrate removal efficiency was obtained at inter-electrode distance 1 cm, agitation speed 300 rpm, electrolyte concentration of 1.1688 (g/L) NaCl, current 1.5 A and time 180 min for initial nitrate concentration of 100 (mg/L). Isotherm and kinetics models have been studied and it was observed from the present investigation that the process follows pseudo-second-order kinetics. The Freundlich isotherm model simulations match satisfactorily with the experimental observations. Further, optimised parameters were used to remove nitrates from real groundwater and 92.5% removal efficiency was attained.

•Photocatalytic removal of Cd(II) by photo-catalysis was investigated.•Bi/S doped carbon dots with improved electron-hole availability were used as photocatalytic material.•Use of scavenger solvents was explored for consuming the holes for reducing electron-hole recombination.•Langmuir, Freundlich and Temkin isotherms were applied on the removal of Cd(II).•Gibbs energy change, enthalpy change and entropy change were estimated.

Lignocellulosic biomass is a promising form of renewable energy, and its exploitation is readily increasing due to the several challenges over the consumption of fossil fuels, that is, climate change, energy security, global warming, and their negative impacts on human health. Different sources of biomass are available, and each possesses different chemical compositions and properties which leads to variation in the yield and selectivity. The higher yield of bio-products can be achieved via effective conversion technologies (i.e., thermo-chemical, biochemical, and physicochemical conversions). Recent technological advancements in biomass exploitation have led to the development of potential methods for the efficient manufacture of biofuels from these readily available, low-cost natural resources. Hence, suitable optimization of process parameters including temperature, reaction time, feedstock selection, pretreatment strategy, and pressure effectively enhances the production of biofuels and promotes green and clean manufacturing along with circular economy.

The continuous destruction of the environment, the volatility of the oil market, and the poor performance of conventional sources derived from fuels have spurred the search for alternative fuels. The production of biofuels is driven by several important needs and considerations, primarily aimed at addressing environmental, economic, and energy security challenges. The valorization of agricultural waste biomass through effective pretreatment is a critical step in the biorefinery process, which aims to convert biomass into various value-added products, such as biofuels, bio-based chemicals, and bio-based materials. Effective biomass pretreatment offers several advantages including enhanced reactivity, increased enzymatic digestibility, reduced inhibitors, higher yield of products, faster reaction rates, energy efficiency, waste reduction, flexibility in feedstock choice, and reduced environmental impact. Transformation of biomass to value-added products does not compromise food security; it aids waste management, protects the environment, and ensures energy security.

Minimizing carbon footprints has become imperative to mitigate the adverse impacts of climate change and ensure a sustainable future. The synergistic combination of minimizing carbon footprints present in soil, water, and air by implementing bioremediation technologies using bio-systems is essential. Microalgae fermentation, a subset of bioremediation, has drawn a lot of interest considering the potential over other bio-approaches to utilize carbon for bringing environmental sustainability. Diverse microalgae in the environment are microscopic, photosynthetic organisms, which exhibit numerous qualities that make them an ideal biosystem for bioremediation. This review reveals the cohesive process of an exceptional microalgae system over and above other plant-based systems requiring land for growth. It presents and analyses microalgae fermentation and bioremediation highlighting the significance and applicability of microalgae culture for bringing a sustainable environment. It also encompasses detailed insight into the selection and cultivation of felicitous microalgae, different modes of operations to optimize fermentation conditions with metabolic engineering for enhanced CO2 sequestration, nitrogen utilization, heavy metals, and dye bioremediation to produce value-added products such as antioxidants, lipids, pigments, and proteins. Economic and financial aspects of low-carbon development and long-term transition to net zero are discussed. This review is offering an innovative solution for energy, via microalgae-based biodiesel, transitioning to microalgae-based systems having improved energy efficiency due to carbon capture and storage technologies promotes afforestation and reforestation results in sustainable land management, and engaging in carbon offsetting by adopting circular economy principles are vital strategies for reducing carbon footprints and mitigating climate change. Along with emphasizing the usage of such systems for industrial and commercial purposes in the future for achieving UN-SDGs.

Slaughterhouse sludge is a highly polluting waste generated by the meat processing industry. Its disposal poses significant environmental challenges due to its high organic content, unpleasant odour, and potential contamination risks. However, this waste can also be an excellent source of renewable energy in the form of biogas through anaerobic digestion. Microwave pretreatment is a promising technology to improve the biodegradability of slaughterhouse sludge and maximize biogas yield. In this study, we optimized the microwave pretreatment conditions by using response surface methodology (RSM) for slaughterhouse sludge to enhance sCOD value and hence biogas production. The results showed that microwave pretreatment enhances the maximum sCOD value by up to threefolds in the selected design space. Optimal microwave pretreatment conditions were a temperature of 59.8 °C, a treatment time of 4.9 min, and a power level of 343.8 W, which increased sCOD value by 2.13-folds. Biogas production of slaughterhouse sludge increased from 90 Nml/g-VS (untreated) to 490 Nml/g-VS (microwave pretreated) after microwave pretreatment. With a 5.44-fold increase in specific biogas yield production of microwave-pretreated sludge compared to untreated sludge, the microwave pretreatment method proved to be a suitable method for the enhancement of biogas production.

Diverse feedstocks utilized in anaerobic digestion (AD) pose challenges to enzymatic disintegration because of their nature and complex physical structures and thereby limiting biogas generation. To overcome this, the AD process is often combined with pretreatment techniques, which facilitate the breaking of organic feedstock into smaller molecules and eventually result in enhanced biogas production. Among several techniques, ultrasound-assisted pretreatment of AD feedstock remains promising because it is simple to implement, requires no chemicals, and combines physical (or cavitation) and biological phenomena for degrading AD feed. This review is primarily centered on the applications of ultrasound pretreatment for disintegrating various feedstocks and increasing biogas production during AD. Biogas generation is described in relation to the ultrasound-assisted disintegration of dairy industry waste, hybrid food and municipal wastes, olive mill wastewater, rice straw, tannery wastewater, meat processing sludge, hybrid industrial waste municipal sewage sludge, and lignocellulosic biomass. The disintegration schemes of feedstocks under ultrasound are proposed. COD is solubilized, and suspended solids (SS) are reduced upon ultrasonication. The impact of ultrasonic treatment on biogas production might be amplified if paired with alkali. Furthermore, the techno-economic commercial scopes of ultrasound pretreatment-based biogas production are discussed, and recommendations for future studies are suggested.

In the present study, hydrophilic silica aerogel (HPSA) was synthesized by ambient pressure drying method and was successfully used as an adsorbent for the removal of Cationic dyes (Crystal violet- CV) from the aqueous solution. The synthesized sample was characterized and examined by Fourier transform infrared spectroscopy (FTIR), Bruner – Emmett – Teller (BET), x-ray diffraction (XRD), Zeta potential pH zp, Nuclear Magnetic Resonance Spectrometer (NMR), and Scanning Electron microscope (SEM). The effect of different parameters such as pH, initial concentration of dyes, contact time, temperature, and their effect on the removal of CV dyes was studied. Silica aerogel synthesized was excellent and 96 % removal of CV dyes on the optimum value of the parameters of 30 min contact time, 303 K temp, 7 pH, 50 mg/l Conc., 0.3 g/l dose of HPSA was obtained. Langmuir, Freundlich, Temkin,and D-R models were applied in the equilibrium studies and obtained the maximum adsorption capacity 137.17 mg/g. pseudo-first, second-order, and intraparticle diffusion models were employed to indicate the chemisorption behavior in the kinetic study on the adsorption. Thermodynamic parameters showed the adsorption process as Exothermic and spontaneous. Sticking Probability (S*≪1) indicated HPSA as a good adsorbent for the removal of dyes. HPSA has demonstrated the potential for regeneration while affirming its remarkable removal efficiency, Cost effectiveness and Environmental compatibility.

The production of a wide range of value-added products is heavily dependent on conventional fuels. With an annual growth rate of around 7%, the waste to energy sector in India could reach 14 billion USD by 2025. Despite continuous increase in energy demands, several types of underutilized wastes are generated from energy crops, anthropogenic, forestry, and municipal, agricultural, and industrial activities in huge quantities to maintain the country’s growth. It is estimated that nearly 560 billion tons of biomass is available on Earth, while the total primary production is ~100 billion tons/year. There is a surplus of agricultural and forest land in India, which produces about 500 million metric tons of biomass every year. In the last 50 years, agricultural production has increased by more than three times due to the expansion of agricultural soil. As agricultural products become more popular, this demand is expected to increase. Agricultural wastes include crop waste, livestock waste, food processing wastes, and animal wastes. Also, in agriculture farm, 5.3 kg of manure is generated per 100 kg of live weight (wet weight) each day. Biofuels and aromatics can be produced from lignocellulosic biomass, which is an economical, renewable, and abundant alternative to fossil fuels. As part of a bio-based economy and a biorefinery, there is a significant opportunity for the development of biodegradable building blocks (monosaccharides, oligosaccharides, biofuels, and polymers) and materials (fiber products, cellulose nanofibers, starch derivatives, and furfurals). Bioenergy needs to be modernized to fit into a sustainable, environmentally friendly, economically viable, and socially responsible development pathway. Various conversion technologies and pathways are capable of solubilizing diverse chemical constituents and are used for the production of a wide range of bio-derived intermediates and end products. The efficiency of conversion technologies differs greatly and depends on the type of biomass used as raw material, which may contain different fractions and compositions of cellulose, hemicellulose, and lignin. With the rising demand, high cost, and emerging environmental concerns of fossil fuels, the monetization of biomass waste can provide significant benefits. This chapter explores the potential of waste biomass as a promising source for commercially viable industrial chemicals such as monosaccharides, biofuels, and oligosaccharides.

In this work boron and phosphorous co-doped carbon quantum dots were synthesized using hydrothermal and microwave assisted heating. Modified carbon dots were used for their applications in removal of methylene blue from waste water. Effect of photo-reactor design parameter (power of light source, distance between light source and reactor) and pH was investigated and was optimized at pH 11. It was observed that the carbon dots prepared by microwave assisted method were more efficient in terms of methylene blue degradation with higher Methylene blue removal upto 92.3%. Kinetics behind degradation of methylene blue by using pseudo first and pseudo second order models was studied with regression coefficient value 0.9934. Effect of diffusion parameter on the methylene blue removal was studied using intraparticle, film and Boyd models.

Present study focused on abundantwaste of Aloe. barbadense miller leaves treated with sodium bicarbonate(MABL) for the removal of Cd (II) from aqueous solution and industrial effluent using fixed bed continuous process.The experimentation data obtainedfrom breakthrough curves for different conditions (flow rate = 10--30 mL/min, Cd (II) concentration from 20 to 60 mg/L, Different bed height (Bio-adsorbent doses = 10-30 g).Uptake capacity ofCd(II) increased with increased bed depth but remained constant at any flow rate.The optimum conditions obtained were a flow rate 10 mL/min, bed height of 10 cm, and initial concentration of 20 mg/L at the maximum total adsorption capacity is 54.05 mg/g and removal efficiency is 56.3 %. Characterization of the scanning electron microscopy analysis-energy dispersive X-ray spectroscopy (SEM-EDX) analysis confirms the adsorption of Cd (II) in the bio-adsorbent surface. Column behaviors was predicted by mathematical model with desirable accuracy. Thomas model was the best Kinetics model in the biosorption process on the Cd(II) with good correlation coefficient of the experimental data in comparison of Yoon Nelson model,Bohart- Adam model (R2 > 0.90).The efficiency of bio-adsorbent regeneration achieved by 0.1 M HCl was very high, that was 50-33 % for Cd (II)during first to third reused cycle. MABL is also used to removal of Cd (II) by applying a semi-simulated real wastewater in fixed bed column So that it can be concluded that MABL is a good bio-adsorbent for treating wastewater having low concentrations of Cd (II) contamination.

In the present study, the decolorization of a solution containing four dyes--acid violet 17 (AV 17), malachite green (MG), methylene blue (MB), and Congo red (CR)--was performed using electrocoagulation (EC) with the help of aluminum electrodes. A Box-Behnken design with three factors--current, electrode spacing, and pH--was used to optimize the factors for greater dye removal efficiency. A reasonably good fit was obtained for acid (AV17 and CR) and basic (MG and MB) dye removal under optimized conditions (pH 5, electrode spacing 1 cm, and current 0.03 A/cm(2)). High coefficient-of-determination values was obtained for the acid and basic dyes (R-2 = 0.979 and 0.977, respectively), implying a good fit for both regression models. Maxima of 76.6% and 73.8% dye removal were obtained under optimized conditions, confirming that the EC process is a viable option for dye removal. (c) 2022 American Society of Civil Engineers.