INOVASI TEKNOLOGI MODEL FILTRASI UNTUK MENGURANGI KANDUNGAN MIKROPLASTIK PADA AIR IRIGASI DAN DAMPAKNYA TERHADAP PERTUMBUHAN TANAMAN PADI

Plastic mulch and irrigation water contribute significantly to the accumulation of microplastics (MP) in fertile soils. The progressive enrichment of plastic fragments in mulched soils has been well documented. Agricultural lands covered with plastic mulch and irrigated with contaminated water may contain high levels of MP, indicating that irrigation water serves as a critical vector for the entry and distribution of MP. While several studies in Taiwan have examined MP distribution in marine and riverine environments, limited information is available regarding MP contamination in irrigation water. This study aimed to: (1) Identify and characterize MP present in irrigation water used by farmers to irrigate rice fields in Pamekasan Regency, (2) Analyze the physiological and biochemical effects of MP photoaged-contaminated water on rice plants (Oryza sativa L.), and (3) Provides efficiency of various activated carbon materials in reducing microplastic content in the air. The research was conducted from October 2023 to Desember 2024 at several laboratories: the Islamic University of Madura, Nahdlatul Ulama University of Surabaya, the Animal House Laboratory, and the Biomedical Laboratory at the Faculty of Medicine, Muhammadiyah University of Malang. The study was structured into three Stages: Stage I: Identification and Characterization of Microplastics in Irrigation Water Samples were collected from three distinct locations: reservoir dam (W1/S1), residential water source (W2/S2), and agricultural land (W3/S3). MP were characterized by their abundance, color, size, shape, and polymer type. The analysis revealed MP in all sampling points, both in water and sediment. MP concentrations ranged from 0.5 to 0.9 particles/L in water, and 0.14 to 0.23 particles/gram in sediment. Identified MP varied in color (black, blue, yellow), size (0.1–2.9 mm), and were primarily composed of polyethyleneimine (PEI) and polypropylene (PP) two common polymers used in household and industrial products. Stage II: Impact of Naturally Aged Microplastics on Rice Plants This Stage evaluated the effects of weathered microplastics on rice physiology by simulating three types of PS-MP (polystyrene microplastic) exposure: ULPS: Untreated plastic particles with intact additives, LPS: Aged particles with additive release, L: Leachate solution from weathered plastic Stage III focused on filtration using sand column systems enhanced with agricultural waste-derived activated biochar. Three biochar types rice husk, hardwood, and coconut shell—were compared, both with and without chemical activation. Four types of MP (PS10–15, PET6–9, PA5, PSnano) were used to assess filtration efficiency. Stage I found MP in all water and sediment samples, ranging from 0.5–0.9 particles/L in water and 0.14–0.23 particles/g in sediment. MP varied in color (black, blue, yellow), size (0.1–2.9 mm), and were predominantly polyethyleneimine (PEI) and polypropylene (PP) common household and industrial polymers. Stage II showed that photoaged PS-MPs significantly inhibited rice growth, with ULPS treatment having the most severe effects: root length decreased by 31%, fresh biomass by 30%, and chlorophyll a and b by 53% and 56%, respectively. A 23% increase in antioxidant enzyme activity indicated oxidative stress, reinforcing evidence of microplastic-induced metabolic disruption. MP were also detected in root tissues, suggesting both physical (pore blockage) and chemical (toxic leachate) pathways for plant contamination. Stage III demonstrated that integrating activated biochar into sand columns significantly improved MP removal efficiency to 95–97%, particularly with hardwood-based biochar. PS10–15 particles showed the highest removal rate (96.82%), and even nano-sized MP were filtered with >95% efficiency. The enhanced performance was attributed to the chemically activated biochar’s high surface area, strong adsorption capacity, and complex porous structure.