• RAMPRAKASH PRAJAPATI
• RASHMI SINGHAI

Green chemistry perceives the concept of developing innovative environmental benign technologies and improving the resource intensity. In order to explore this concept for minimizing the industrial waste and for reducing the environmental impact of hazardous chemicals. The paper focuses on green approach to extract metals like Ni,Cu,Mo, Fe, Zn, Rh and Pd from spent catalyst, which contain substantial quantity of heavy metals and may affect the ecosystem. The chelation technology is an ecofriendly process for extraction of heavy metals from spent catalyst obtained from fertilizer industry. Green chemistry recognizes the concept of developing innovative environmentally benign technologies to protect human health and ecosystems. In order to explore this concept for minimizing industrial waste and for reducing the environmental impact of hazardous chemicals, new greener approaches need to be adopted for the extraction of heavy metals from industrial waste. In this review, new green approaches employed for metal extraction are discussed in brief. Chelation technology, a modern research trend, has shown its potential to develop sustainable technology for metal extraction from spent catalysts and various metal-contaminated sites. However, the interaction mechanism of ligands with metals and the ecotoxicological risk associated with the increased bioavailability of heavy metals due to the formation of metal–chelate complexes. Therefore, a need felt to provide a comprehensive state-of–the-art of aspects associated with chelation technology to promote this process as a green chemistry approach. Chelation technology elucidates the mechanism associated with metal–ligand complexation in order to have a better understanding of the metal extraction process. The effects of various process parameters on the formation and stability of complexes have been elaborately discussed with respect to optimizing the chelation efficiency. Therefore, biotechnological approaches have been assessed to illustrate the possibility of ligand degradation, which will help to look for new environmentally safe mobilizing agents. Chelation technology as a potential ecofriendly method to extract heavy metals from spent catalysts. Chelation technology have been carried out for extraction of transition metals from spent catalyst samples obtained from fertilizer and petrochemical industries using different biodegradable chelating agents(NTA ,EDDS,IDSA ,MGDA & GLDA ).

Spent catalysts, chelation technology, chelating agents, biodegradability, solid wastes minimization, fertilizer industry, metal extraction, pollution, ecofriendly approaches,

"ECO-FRIENDLY CHELATING AGENTS FOR EXTRACTION OF METAL FROM SPENT CATALYSTS OF FERTILIZER INDUSTRY", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.7, Issue 10, page no.3717-3729, October-2020, Available :http://www.jetir.org/papers/JETIR2010484.pdf

"ECO-FRIENDLY CHELATING AGENTS FOR EXTRACTION OF METAL FROM SPENT CATALYSTS OF FERTILIZER INDUSTRY", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.7, Issue 10, page no. pp3717-3729, October-2020, Available at : http://www.jetir.org/papers/JETIR2010484.pdf