Nano-zero-valent particles synthesized with agroindustry wastes for pesticide degradation under real conditions

Abstract

Nano-zero-valent particles (NZVP) had exhibited high degradation activity. NZVP synthesized from agroindustry residues align with circular economy principles. They generate hydroxyl radicals (4.6 µM) that effectively degraded chlorpyrifos-methyl pesticide under real conditions. Bimetallic NZVP, specifically NZVP-Fe:Mn and NZVP-Fe:Ag, show superior pesticide degradation. The metal ratio within NZVP influences their activity (optimal at 0.12:0.12 mM and 0.12:0.19 mM for respectively, NZVP-Fe:Mn and NZVP-Fe:Ag). NZVP characterization includes TEM, SEM-EDS, PZC, FTIR, XRD, and electrochemical analysis, confirming their acid nature, favorable electrochemical behavior, and uniform metal distribution. The impact of different natural extracts on NZVP synthesis and pesticide degradation was explained through extensive extract characterization, revealing the presence of altering pro-oxidants and scavenger species. Blueberry pruning extract yields the highest pesticide degradation (85% in 5 min) due to its stronger antioxidant activity and lower scavenger compound content. NZVP demonstrates efficacy across various pH ranges. Real wastewater samples were treated under optimal conditions, resulting in a pesticide degradation efficiency of approximately 60% within 5 min. The most effective approach for enhancing the treatment process involved the sequential addition of reagents, as opposed to the conventional method of increasing reagent concentration