The increasing demand for high-performance activated carbon necessitates applying sustainable and cost-effective production methods. This study explores the use of biochar derived from renewable biomass. The primary feedstock for biochar consisted of woody residues from composting, along with pre-dried sunflower seed shells that had a moisture content of around 10% as a precursor for the production of activated carbon. The process started with carbonization followed by potassium hydroxide (KOH) activation. Key parameters such as the impregnation ratio, temperature, and activation time were optimized to enhance the physicochemical properties of the activated carbon. Under optimized conditions, namely a KOH-to-biochar impregnation ratio of 3:1, an activation temperature of 800 °C, and an activation duration of 5 h, the yield of activated carbon was 58% and the specific surface area was 498 m²/g. A significant enhancement in surface area, with a maximum value of 709 m²/g, was achieved after increasing the time to 24 h of activation. Differential Scanning Calorimetry (DSC) analysis was applied to evaluate the CO₂ adsorption performance of both biochar and activated biochar at 30 °C, demonstrating a 30% improvement in adsorption efficiency following activation. This study underscores the potential of biochar as a renewable and sustainable precursor for the production of high-performance activated carbon. This study underscores the potential of biochar derived from agro residue as a source for the production of high-performance activated carbon. The findings contribute to the advancement of environmentally friendly production technologies and highlight the potential applicability of biochar-derived activated carbon in gas adsorption and environmental remediation.

Lactic acid (LA) is an organic acid produced by fermentation or chemical synthesis. It plays a crucial role in the pharmaceutical, food and plastic industries. In the fermentation of, for example, grass silage, LA and different compounds are produced. To purify lactic acid, researchers have tried to investigate membrane technology to achieve a high yield of lactic acid permeance. This study tested four commercially available nanofiltration membranes (NF270, MPF-36, Toray NF, and Alfa Laval NF). Nanofiltration experiments were performed to investigate the rejection levels of lactic acid from a binary solution by using distinct molecular weight cut off membranes. All of the experiments were conducted with a lab-scale cross-flow membrane unit. Different operating conditions (pH, temperature) were studied for each membrane; the optimal process condition was found at 25 °C and pH 2.8. With higher temperatures and pH, an increase in LA rejection was observed. The MPF-36 membrane shows the lowest lactic acid rejection yield of 7%, while NF270 has the highest rejection yield of 71% at 25 °C and pH 2.8. These results will be helpful in the future to understand both the interaction of lactic acid permeance through nanofiltration membranes and process scale-up.

The increasing demand for high-performance activated carbon necessitates applying sustainable and cost-effective production methods. This study explores the use of biochar, derived from renewable biomass. The primary feedstock for biochar consisted of woody residues from composting, along with pre-dried sunflower seed shells that had a moisture content of around 10% as a precursor for the production of activated carbon. The process started with carbonization followed by potassium hydroxide (KOH) activation, key parameters such as the impregnation ratio, temperature, and activation time were optimized to enhance the physicochemical properties of the activated carbon. Under optimized conditions, namely a KOH-to-biochar impregnation ratio of 3:1, an activation temperature of 800 °C, and an activation duration of 5 hours, the yield of activated carbon is 58% and a specific surface area of 498 m²/g. A significant enhancement in surface area, with a maximum value of 709 m²/g achieved after increasing the time to 24 hours of activation. differential scanning calorimetry (DSC) analysis was applied to evaluate the CO₂ adsorption performance of both biochar and activated biochar at 30°C, demonstrating a 30% improvement in adsorption efficiency following activation. This study underscores the potential of biochar as a renewable and sustainable precursor for the production of high-performance activated carbon. The findings contribute to the advancement of environmentally friendly production technologies and highlight the potential applicability of biochar-derived activated carbon in gas adsorption and environmental remediation.

Sugar production generates wastewater rich in dissolved solids and organic matter, and improper disposal poses severe environmental risks, exacerbates water scarcity, and creates regulatory challenges. Conventional treatment methods, such as evaporation and chemical precipitation, are energy-intensive and often ineffective at removing fine particulates and dissolved impurities. This study evaluates membrane-based separation as a sustainable alternative for water reclamation and sugar recovery from sugar industry effluents, focusing on replacing evaporation with membrane processes, ensuring high permeate quality, and mitigating membrane fouling. Cross-flow filtration experiments were conducted on a lab-scale membrane system at 70 °C to suppress microbial growth, comparing direct reverse osmosis (RO) of the raw effluent to an integrated ultrafiltration (UF)–RO process. Direct RO resulted in rapid membrane fouling. A tight UF (5 kDa) pre-treatment before RO significantly mitigated fouling and improved performance, enabling 28% water recovery and 79% sugar recovery, maintaining permeate conductivity below 0.5 mS/cm, sustaining stable flux, and reducing membrane blocking. Additionally, the UF and RO membranes were tested via SEM, EDS, and FTIR to elucidate the fouling mechanisms.

Sugar production generates wastewater rich in dissolved solids and organic matter, and improper disposal poses severe environmental risks, exacerbates water scarcity, and creates regulatory challenges. Conventional treatment methods, such as evaporation and chemical precipitation, are energy-intensive and often ineffective at removing fine particulates and dissolved impurities. This study evaluates membrane-based separation as a sustainable alternative for water reclamation and sugar recovery from sugar industry effluents, focusing on replacing evaporation with membrane processes, ensuring high permeate quality, and mitigating membrane fouling. Cross-flow filtration experiments were conducted on a lab-scale membrane system at 70 °C to suppress microbial growth, comparing direct reverse osmosis (RO) of the raw effluent to an integrated ultrafiltration (UF)–RO process. Direct RO resulted in rapid membrane fouling, which was characterized via SEM, EDS, and FTIR to elucidate the fouling mechanisms. A tight UF (5 kDa) pre-treatment before RO significantly mitigated fouling and improved performance, enabling 75 % water recovery, maintaining permeate conductivity below 0.5 mS/cm, sustaining stable flux, and reducing membrane blocking.