Temporal Dynamics of Total Organic Matter in the Brantas River, Kediri City, Indonesia

Mas&#039;ud, Faisol; Zamzami, Ilham Misbakudin Al; Ristyanadi, Bhiaztika

doi:10.21608/ejabf.2025.434692.6851

Temporal Dynamics of Total Organic Matter in the Brantas River, Kediri City, Indonesia

Document Type : Original Article

Authors

¹ Departement of Aquatic Resources Management, Faculty of Fisheries and Animal Science, Lamongan Islamic University

² Coastal and Marine Research Center Brawijaya University, Brawijaya University, Malang 65145, Indonesia

10.21608/ejabf.2025.434692.6851

Abstract

This study aimed to analyze the temporal dynamics of total organic matter (TOM) and to assess the level of organic pollution relative to water quality standards in the Brantas River ecosystem, Kediri City, Indonesia. The research was conducted in the downstream section of the Brantas River using a descriptive exploratory approach. The measured parameters included TOM, total suspended solids (TSS), turbidity, total solids (TDS), nitrate (NO₃⁻), ammonia (NH₃), total oxygen (DO), pH, and temperature. Data were analyzed based on the classification system of the Indonesian Government Regulation No. 82/2001 concerning water quality management and pollution control. Results showed that the average concentration of TOM increased from 22.1mg/ L in the morning to 24.3mg/ L in the afternoon, indicating a 9.95% rise. TDS levels exhibited a minor change between morning (419mg/ L) and afternoon (423mg/ L) with a 0.95% increase. Nitrate concentrations slightly decreased from 3.5 to 3.8mg/ L, while TSS increased from 8.9 to 11.8mg/ L during the same period. These variations reflect the influence of diurnal anthropogenic activities such as TOMestic wastewater discharge, small-scale industrial effluents, and agricultural runoff on the temporal fluctuations of water quality. The findings highlight the importance of continuous monitoring of organic matter dynamics as an indicator of pollution in the Brantas River to support sustainable watershed management in Kediri City.

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