Construction of hollow fiber nanofiltration separation layer with bridging network structure by polymer-anchored co-deposition for high-concentration heavy metal ion removal

Tannic acid as a green chemical for the removal of various heavy metals: A critical review of recent developments

Heavy metals are persistent, bioaccumulative, and toxic pollutants that greatly challenge the environment. Pursuing green and efficient methods to remove these contaminants from wastewater has become a key focus in environmental research. Tannic acid (TA), a natural plant-derived secondary metabolite, has demonstrated exceptional potential for heavy metal removal. This review provides a comprehensive analysis of TA-based materials, focusing on their performance, influencing factors, underlying mechanisms, thermodynamic models, and regeneration in the removal process. Enhancing the adsorption capacity of TA-based materials for targeted heavy metals remains a priority, requiring further modifications and optimizations. Expanding the operational range of pH and temperature and minimizing interference from coexisting substances are also crucial for practical applications. Additionally, kinetic and adsorption models offer valuable insights into removal mechanisms while providing predictions and guidance for real-world implementations. By offering an in-depth overview, this review serves as a critical resource for advancing the development of sustainable and effective TA-based adsorbents for wastewater treatment.

Manufacturing sulfated cellulose nanofibers using a unique combined DES-based pretreatment-functionalization protocol for metal ion decontamination through porous adsorbents

This study confirms the efficacy of a unique combined pretreatment-functionalization protocol based on the use of deep eutectic solvent (DES) to obtain sulfated lignocellulose and cellulose nanofibers (SLNF or SNF) hydrogels, which have been successfully shaped as sponge-based adsorbents and fruitfully assessed for the removal of heavy metals from water. A comprehensive characterization study was conducted, demonstrating an excellent degree of sulfation (0.62) in DES-treated wheat straw-derived nanofibers. The direct use of SLNF or SNF hydrogels and their application as porous sponges exhibited highly favorable characteristics for successful ion decontamination. Cu2+ removal was up to 70 % higher using DES-sulfated nanocellulose hydrogels compared to conventional treated-nanocellulose. Various isotherm models were studied, and the analysis of the kinetic and diffusion studies confirmed the influence of the sample format in the removal behavior. SLNF and SNF-sponges proved to be the most effective in adsorption, achieving Cu2+ removal rates of up to 60 %. More profitable decontamination processes with lower run times could be guessed when the application of nanocellulose is led through the processing of advanced formats. The easy handling of sponges would avoid the extra costs of the downstream unit operations which are sometimes needed to separate the hydrogel of the decontaminated media.

Microbial strategies for copper pollution remediation: Mechanistic insights and recent advances

Environmental contamination is aninsistent concern affecting human health and the ecosystem. Wastewater, containing heavy metals from industrial activities, significantly contributes to escalating water pollution. These metals can bioaccumulate in food chains, posing health risks even at low concentrations. Copper (Cu), an essential micronutrient, becomes toxic at high levels. Activities like mining and fungicide use have led to Copper contamination in soil, water, and sediment beyond safe levels. Copper widely used in industries, demands restraint of heavy metal ion release into wastewater for ecosystem ultrafiltration, membrane filtration, nanofiltration, and reverse osmosis, combat heavy metal pollution, with emphasis on copper.Physical and chemical approaches are efficient, large-scale feasibility may have drawbackssuch as they are costly, result in the production of sludge. In contrast, bioremediation, microbial intervention offers eco-friendly solutions for copper-contaminated soil. Bacteria and fungi facilitate these bioremediation avenues as cost-effective alternatives. This review article emphasizes on physical, chemical, and biological methods for removal of copper from the wastewater as well asdetailing microorganism's mechanisms to mobilize or immobilize copper in wastewater and soil.

Removal of Copper Ions from Wastewater: A Review

Copper pollution of the world's water resources is becoming increasingly serious and poses a serious threat to human health and aquatic ecosystems. With reported copper concentrations in wastewater ranging from approximately 2.5 mg/L to 10,000 mg/L, a summary of remediation techniques for different contamination scenarios is essential. Therefore, it is important to develop low-cost, feasible, and sustainable wastewater removal technologies. Various methods for the removal of heavy metals from wastewater have been extensively studied in recent years. This paper reviews the current methods used to treat Cu(II)-containing wastewater and evaluates these technologies and their health effects. These technologies include membrane separation, ion exchange, chemical precipitation, electrochemistry, adsorption, and biotechnology. Thus, in this paper, we review the efforts and technological advances made so far in the pursuit of more efficient removal and recovery of Cu(II) from industrial wastewater and compare the advantages and disadvantages of each technology in terms of research prospects, technical bottlenecks, and application scenarios. Meanwhile, this study points out that achieving low health risk effluent through technology coupling is the focus of future research.