Vol. 16 | No. 3 |1396-1402| July - September | 2023 ISSN: 0974-1496 | e-ISSN: 0976-0083 | CODEN: RJCABP http://www.rasayanjournal.com http://www.rasayanjournal.co.in Rasayan J. Chem., 16(3), 1396-1402(2023) http://doi.org/10.31788/RJC.2023.1638318 This work is licensed under a CC BY 4.0 license. PHOTOCATALYTIC DEGRADATION OF LAMBDA- CYHALOTHRIN (PYRETHROID) IN WASTEWATER USING ZINC OXIDE NANOPARTICLE Mahadi Danjuma Sani 1 , V. D. N. Kumar Abbaraju 1 and N. V. S. Venugopal 2, 1 Department of Environmental Science, GITAM School of Science, GITAM (Deemed to be a University), Visakhapatnam, A.P. India 2 Department of Chemistry, GITAM School of Science, GITAM (Deemed to be a University), Visakhapatnam, A.P. India  Corresponding Author: vnutulap@gitam.edu ABSTRACT Accumulating synthetic pesticides in the living system has brought about several critical alerts from researchers as it interferes with the essential processes in the body. Metal oxide nanoparticles possess suitable properties including band gap and have played an important role in the photocatalytic degradation of toxic chemicals in wastewater and the environment under natural solar radiation. This research aims at the photocatalytic degradation of Type II Pyrethroid Pesticide (Lambda-cyhalothrin) in wastewater and agricultural runoff using Zinc Oxide Nanoparticles. The synthesized ZnO Nanoparticle (NP) was ascertained by characterization using XRD for material crystallinity and crystallite size, SEM, and particle size analysis for surface morphology and size. The EDAX spectra confirmed the presence of Zinc elements and showed that the synthesized zinc oxide nanoparticles were pure. The degradation experiment was conducted under natural solar irradiation. The initial and final/equilibrium concentration of Lambda-cyhalothrin residue were determined using High-performance liquid chromatography (HPLC) followed by computation of degradation capacity. Photocatalytic degradation of LCY was successful following the application of Zinc oxide NPs as nanocatalysts with an efficiency of about 87% as compared to the control. The synthesized Nanoparticle was found to degrade a large percentage of Lambda-cyhalothrin residue in wastewater. Exploiting its application in the remediation of pesticides in agricultural runoff may be crucial at this point. Keywords: Lambda-Cyhalothrin, Photocatalytic Degradation, Magnetic Nanoparticle, Wastewater, and Agricultural Runoff. RASĀYAN J. Chem., Vol. 16, No. 3, 2023 INTRODUCTION Continued application of synthetic or chemical pesticides in agriculture, households, and commercial activities made them a case of concern for society and human health. Pesticides are crucial to day in day out activities because they play an important role in food productivity and maintenance of livelihood. However, as a result of the wide application of pesticides in agricultural activities and households, residues of such particles are frequently found in water bodies which directly or indirectly affect the quality of water and disrupt the aquatic ecosystem. In other cases, such particles find their way into the food chain affecting various organisms at different levels. Accumulating synthetic pesticides in the living system has brought about several critical alerts from researchers as it interferes with the essential processes in the body. Studies have shown that the deposition of pesticides into non-target areas including water bodies is one of the major issues regarding pesticides. 1-4 Lambda-cyhalothrin (LCY) is a type II pyrethroid pesticide and is a synthetic insecticide made up of 2 stereoisomers of cyhalothrin with long- term action against pests. 5 It is a neurotoxin that disrupts the functioning of the nervous system in insects, leading to paralysis and later death. 6 It has a wide application across several anthropogenic activities including; agricultural activities 7-9 households and public health and is also considered among the most widely used synthetic pesticides in the whole world as a result of its low persistency as compared to other classes of pesticides, in addition to low toxicity to humans, wide insecticidal activity and spectrum. 10 However, extensive use of LCY pesticide had made it another pollutant/contaminant in the environment. Residues of such synthetic chemical pesticides were found to be present in water bodies, 11-15 vegetables, food, and the living system.