Experimental investigation of Cd (II) ion adsorption on surface-modified mixed seaweed Biosorbent: A study on analytical interpretation and thermodynamics.

Despite advancements in wastewater treatment technologies, heavy metal contamination, especially cadmium (Cd), severely threatens human health and ecosystems. The purpose of this work is to compare the removal of Cd (II) ions from aqueous solutions by chemically modified mixed seaweed biosorbent (CMSB) and physically modified mixed seaweed biosorbent (PMSB). BET, SEM, EDAX, FTIR, and XRD techniques characterized the mixed seaweed biosorbents before and after adsorption. They are well-known for their sustainability, affordability, and biodegradability. The BET study revealed that CMSB had a surface area of 19.682 m2/g, while PMSB had a lower surface area of 14.803 m2/g. The optimum adsorption conditions were a temperature of 303 K, pH of 6.0, and biosorbent dosages of 1 g/L for CMSB and 2.5 g/L for PMSB. For CMSB and PMSB, the most efficient contact times were 40 and 80 min, respectively. The Langmuir model was demonstrated to be the best fit for the experimental data when compared to other isotherm models, with a coefficient of determination, or R2, of 0.9713 and a maximum monolayer capacity of 151.2 mg/g and 181.6 mg/g for physical and chemical activated mixed seaweed biomass. There was a significant relationship between the R2 values of chemically modified and physically modified biomass. The findings demonstrate that pseudo-second-order kinetics more accurately represent the adsorption process than pseudo-first-order and Elovich models. Thermodynamic experiments validated the endothermic, spontaneous and favourable characteristics of the removal process. According to the results of the current study, PMSB and CMSB may be used as effective adsorbents to remove Cd (II) from aqueous solutions.

A comprehensive review on immobilized microbes - biochar and their environmental remediation: Mechanism, challenges and future perspectives.

The environment worldwide has been contaminated by toxic pollutants and chemicals through anthropogenic activities, industrial growth, and urbanization. Microbial remediation is seen to be superior compared to conventional remediation due to its low cost, selectivity towards particular metal ions, and high efficiency. One key strategy in enhancing microbial remediation is employing an immobilization technique with biochar as a carrier. This review provides a comprehensive summary of sources and toxic health effects of hazardous water pollutants on human health and the environment. Biochar enhances the growth and proliferation of contaminant-degrading microbes. The combined activity of biochar and microbes in eliminating the contaminants has gained the researcher's interest. Biochar demonstrates its biocompatibility by fostering microbial populations, the release of enzymes, and protecting the microbes from the acute toxicity of surrounding contaminants. The current review complies with the immobilization technique and remediation mechanisms of microbes in pollutant removal. This review also emphasizes the combined utilization, environmental adaptability, and the potential of the combined effect of immobilized microbes and biochar in the remediation of contaminants. Challenges and future outlooks are urged to commercialize the immobilized microbes-biochar interaction mechanism for environmental remediation.