Vol. 1 No. 1 (2026)

Emerging contaminants (ECs) including pharmaceuticals, microplastics, per- and polyfluoroalkyl substances (PFAS), modern pesticides, and endocrine-disrupting chemicals pose growing threats to Indonesian aquatic ecosystems and human health. This comprehensive review examines the occurrence, sources, environmental impacts, and management approaches for ECs across Indonesia's diverse aquatic environments. Analysis of published research reveals pervasive contamination in Indonesian surface waters, sediments, and biota, with particularly severe pollution documented in Java's industrialized river basins and coastal zones. The Citarum River Basin and Jakarta Bay exemplify critical hotspots where pharmaceutical loads reach hundreds of tons annually (426.1 tons paracetamol, 343.7 tons amoxicillin in Upper Citarum), microplastic abundances rank among the world's highest, and complex industrial chemical mixtures fundamentally alter ecosystem function. PFAS contamination in breast milk samples (average 84 ppt PFOS) exceeds international health advisory limits, while pesticide residues from intensive agriculture contaminate lakes and reservoirs. Indonesia's regulatory framework faces critical gaps, as Government Regulation No. 22 of 2021 addresses conventional pollutants but lacks specific standards for most ECs. Wastewater treatment infrastructure serves less than 10\% of the population, with conventional technologies achieving incomplete EC removal. Monitoring capacity remains constrained by limited analytical infrastructure concentrated in Java, creating substantial geographic data gaps. Despite these challenges, opportunities exist through the Citarum Harum restoration program, growing research capacity, and context-appropriate technologies including nature-based treatment systems and locally-produced activated carbon. Priority interventions include phased regulatory development for well-documented substances, establishment of national monitoring programs with strategic geographic coverage, accelerated wastewater infrastructure deployment emphasizing decentralized solutions, targeted research on tropical-specific fate and effects, and strengthened governance through improved inter-agency coordination. This review provides the first comprehensive synthesis of EC contamination across Indonesia's archipelago, identifying critical knowledge gaps and actionable pathways for protecting aquatic biodiversity, safeguarding fisheries, and achieving sustainable development goals.

Antibiotics are frequently detected in aquatic environments due to incomplete removal in conventional wastewater treatment plants, contributing to the spread of antimicrobial resistance and ecological risks. However, the widespread application of commercial activated carbon for antibiotic removal is limited by its high cost and reliance on non-renewable precursors, creating a need for low-cost, sustainable adsorbents derived from abundant agricultural wastes such as cassava stems (Manihot esculenta). In this work, cassava stem waste from Indonesia was converted into hydrochar via hydrothermal carbonization and subsequently activated by thermal treatment to produce cassava stem--derived activated carbon (CS-AHC). The materials were systematically characterized by XRD, FTIR, Raman spectroscopy, and SEM-EDS, and their adsorption performance toward selected antibiotics in aqueous solution was evaluated through batch experiments. The optimized CS-AHC exhibits a hierarchically porous structure with increased surface area, enhanced graphitic domains, and abundant oxygen-containing functional groups originating from the cassava stem precursor and activation process. These structural and chemical features provide a high density of accessible adsorption sites and favorable interactions with antibiotic molecules, enabling efficient removal from water while valorizing a locally abundant agricultural residue.

Acid mine drainage (AMD) is characterized by low pH, elevated dissolved metals, and high total dissolved solids (TDS), posing long-term risks to receiving waters and creating a need for robust yet practical treatment trains. This study evaluates a hybrid electrocoagulation--adsorption/filtration system for AMD treatment, combining rapid metal removal and pH correction in the electrocoagulation (EC) stage with downstream polishing by silica sand, activated carbon, and zeolite media. Electrocoagulation was carried out using aluminum electrodes at 1, 2, and 3 V with treatment times of 10--120 min. Effluent quality was assessed by Fe concentration, TDS, and pH to capture both metal removal and overall ionic strength reduction. The best overall performance was achieved at 3 V and 120 min, followed by filtration, reducing TDS from 2605 to 612 mg/L and Fe from 12.36 to 1.23 mg/L while increasing pH from 1.98 to 8.7. The EC step primarily destabilized and removed dissolved metals through hydroxide formation and sweep flocculation, whereas the filtration media provided additional adsorption sites for residual ions and colloids, yielding a clearer and more stable effluent. Overall, the hybrid system delivered substantial improvements in AMD quality using simple, low-energy unit operations and locally available media, indicating its potential as a scalable option for mine-impacted waters requiring simultaneous metal removal and pH normalization.

Clean water scarcity remains a critical challenge in many regions of Indonesia, particularly in rural areas such as Sungai Langka Village, Pesawaran Regency, Lampung Province. This study investigates rainwater harvesting (RWH) as an alternative clean water source by developing a combined filtration-adsorption treatment system consisting of three sequential columns—silica sand, activated carbon, and filter membrane—operated in continuous-flow mode. The research objectives include determining rainwater harvesting potential, optimizing the treatment system through artificial water testing, and evaluating treated rainwater quality against regulatory standards. Analysis of rainfall data from 2015–2024 using the Gumbel distribution method yielded a 2-year return period design rainfall of 99.86 mm, corresponding to harvesting potentials of 7.12 m³/hour and 2.94 m³/hour for galvanized iron and asbestos roofs, respectively. System optimization with artificial water demonstrated effective contaminant removal under extreme conditions, achieving up to 62.54% TDS removal and 82.19% Fe removal. Treatment of actual rainwater successfully adjusted pH from 6.83 to 7.65, reduced TDS from 37 to 22 mg/L (40.54%), and decreased Fe concentration from 0.64 to 0.07 mg/L (89.06%), with an Fe adsorption capacity of 0.252 mg/g. All treated water parameters met the Indonesian Minister of Health Regulation No. 2/2023 standards for sanitary hygiene water, confirming the system as a practical and affordable point-of-use solution for improving clean water access in water-scarce rural communities.

Illegal temporary waste disposal (TWD) sites represent a critical challenge in Indonesian cities, driven by inadequate waste management infrastructure. This study develops an integrated GIS-based methodology for identifying illegal TWD sites and formulating evidence-based solutions in Sukarame Sub-district, Bandar Lampung City. Comprehensive field surveys across the 1,771-hectare area documented GPS coordinates and volumes of illegal TWD sites, followed by spatial analysis using overlay and buffer techniques to identify service gaps and evaluate optimal facility locations. Results identified 19 illegal TWD sites containing approximately 129~m³ of waste, with only one legal facility serving the entire sub-district (ratio 1:19). Spatial clustering analysis revealed highest concentrations in Korpri Raya, Sukarame, and Way Dadi Baru villages (5 sites each), while Korpri Jaya village with private collection services had zero illegal sites. Key influencing factors include land use patterns, population density, inadequate government services, and accessibility. The research proposes a dual-strategy solution framework: (1) service enhancement through 20 additional motorized carts to improve collection coverage, and (2) strategic infrastructure expansion with 9 new TWD facilities positioned using 500~m service radius optimization to ensure comprehensive sub-district coverage. This integrated approach advances beyond conventional problem-identification studies by providing actionable, spatially-justified recommendations that address both service delivery and facility placement. The methodology offers a replicable framework for evidence-based waste management planning applicable to other Indonesian cities facing similar urban waste challenges.