Integrated EM4-based anaerobic and aerobic wastewater treatment for sustainable tofu industry effluent management

Background: The Tahu Sehat Sari industrial area in Cokro Village is one of the largest tofu manufacturers, processing 3 tons of soybeans daily with 88 employees. However, wastewater quality tests reveal that the effluent exceeds regulatory limits set by Central Java Regional Regulation No. 5 of 2012, with BOD at 422.5 mg/L, COD at 845 mg/L, and TSS at 1940 mg/L. Effective wastewater treatment is necessary to ensure compliance with environmental standards and minimize pollution. Methods: This study evaluates wastewater treatment alternatives, including Anaerobic Digester, Anaerobic Biofilter, and Aerobic Biofilter, with the addition of Effective Microorganisms 4 (EM4) to enhance organic waste degradation. Wastewater samples were tested for COD, BOD, and TSS levels before and after treatment to assess removal efficiency. Findings: The implementation of EM4 significantly improved wastewater quality, achieving an 86% reduction in COD with a 0.3% EM4 concentration in aerobic treatment. EM4’s fermentation bacteria effectively minimized organic contaminants. The selected treatment methods—Anaerobic Digester, Anaerobic Biofilter, and Aerobic Biofilter—proved suitable for treating tofu wastewater, with final effluent concentrations of COD at 2.4 mg/L, BOD at 0.3 mg/L, and TSS at 35 mg/L, meeting regulatory standards. The estimated cost for the construction of a Wastewater Treatment Plant (WWTP) is IDR 1,177,378,400, with monthly operation and maintenance expenses of IDR 6,110,297. Conclusion: The study confirms that an integrated wastewater treatment system using anaerobic and aerobic biofilters combined with EM4 is effective in reducing organic waste contamination in tofu industry effluent. Further assessment of land use and distribution systems is recommended to optimize wastewater management. Novelty/Originality of this article: This research contributes to sustainable wastewater treatment in tofu production by integrating EM4 technology with anaerobic and aerobic filtration, achieving high pollutant removal efficiency. The study also provides a financial analysis of WWTP implementation, highlighting its feasibility for similar small and medium enterprises

Assessing plastic waste management performance: Insights from the waste management performance index

Background: In 2015, Indonesia was the second-largest contributor to marine debris worldwide, with an estimated 0.48-1.29 million metric tons of marine waste. In Jakarta, the marine waste generation reached 303.6 tons per day. Government programs such as JAKSTRADA and JAKSTRANAS aim to reduce plastic waste by 30% and manage 70% of waste by 2025. These policies promote circular economy-based waste management, but household participation remains low, with only 1.6% contributing to the 3R (reduce, reuse, recycle). Methods: This study employs both quantitative and qualitative approaches to measure the performance of circular economy-based plastic waste management in Jakarta. The population includes both formal and informal sectors, such as waste banks and waste pickers. Data is analyzed using the Waste Management Performance Index (IKPS) from SIPSN and BPS, comparing plastic waste management achievements with JAKSTRADA targets up to 2025. Findings: In Jakarta, per capita waste generation is 0.7 kg/day, mainly organic and plastic. Despite a decline in collected waste, plastic waste is rising. Management follows Law No. 18/2008 and Presidential Regulation No. 97/2017, involving formal (TPS 3R, waste banks) and informal (collectors, vendors) sectors. The informal sector aids recycling by collecting plastic from inaccessible areas. JAKSTRADA targets waste reduction, handling, and recycling until 2025. The Waste Management Performance Index (IKPS) evaluates policy, effectiveness, and efficiency. Conclusion: Waste management in Central Jakarta is still low with an index of 26% and a recycling rate of 12.6%, despite achieving 99.98% of the collaboration target. Novelty/Originality of this article: This study highlights the integration of formal and informal sectors in plastic waste management in Central Jakarta, emphasizing the use of the Waste Management Performance Index (IKPS) to assess policy effectiveness and recycling progress toward JAKSTRADA targets

Utilization of used lubricating oil for anfo-emulsion production: A study on blasting activities in the copper mining area

Background: Copper is crucial for the development of electric vehicles and renewable energy technologies. In Indonesia, PT ABC's open-pit mining operations are expanding, leading to increased waste generation, particularly used lubricating oil, which is contaminated with water and metal particles but has caloric value comparable to diesel. This study explores the potential of using this oil as a diesel substitute in explosives, focusing on economic and environmental benefits. Method: The study used data collection methods to measure the annual volume of waste oil, cost savings from using it as a fuel substitute, and compliance with hazardous waste utilization regulations. The research analyzed the impact of substituting up to 80% of diesel fuel requirements with used lubricating oil. Findings: PT ABC utilizes approximately 2,699,850 liters of used lubricating oil annually. The company achieves a 99.99% compliance rate with hazardous waste permits. Substituting up to 80% of diesel with used oil resulted in an economic gain of IDR 38,885,321,437 in 2023 and diesel procurement savings of IDR 2,473,012,791. These findings highlight the economic and environmental advantages of waste management practices in mining operations. Conclusion: The integration of used lubricating oil as an alternative fuel in mining operations reduces operational costs, enhances environmental sustainability, and aligns with circular economy principles. This approach contributes to sustainable mining practices by transforming waste into reusable resources, offering significant economic and environmental benefits. Novelty/Originality of this article: This study is original in demonstrating the use of used lubricating oil as a substitute for diesel fuel in mining, showing its potential to reduce costs, improve sustainability, and support circular economy practices in the mining sector

Optimizing sustainable consumption: Understanding reusable lunch box usage intentions through the theory of planned behavior

Background: The shift from using single use to reusable lunch boxes presents a challenge for college students. The economic circular framework is now applied not only to industrial processes but also to consumption behavior. This study aims to examine how the Theory of Planned Behavior (TPB) model, including attitude, subjective norms, perceived behavioral control, moral norms, descriptive norms, and self-identity, influences the intention to use reusable lunch boxes. Method: The study involved 110 undergraduate students from a college campus in Denpasar City. Participants completed questionnaires distributed using a snowball sampling technique. Data analysis was conducted using Partial Least Squares Structural Equation Modeling (PLS-SEM). Findings: The study found that perceived behavioral control and self-identity significantly affect the intention to use reusable lunch boxes. The R-square analysis indicated that 31.1% of students' intention to use reusable lunch boxes was influenced by subjective norms, while 26.4% was influenced by self-identity. Conclusion: The study concludes that perceived behavioral control and self-identity play key roles in students' intention to use reusable lunch boxes. Future research should focus on making reusable lunch boxes more convenient and integrating them into a system that encourages behavior change on college campuses. Novelty/Originality of this article: This study applies the Theory of Planned Behavior to understand college students' intentions to adopt reusable lunch boxes, offering valuable insights for promoting sustainable consumption behavior in a campus setting

Potential of nanotechnology-based nanomaterials and biochar for tofu wastewater filtration: A review on clean water sustainability

Background: Water pollution, driven by industrial activities and population growth, increasingly contaminates water sources, threatening clean water supply. Tofu wastewater, rich in organic pollutants, exacerbates this issue, highlighting the need for sustainable, effective water treatment solutions. Methods: This study uses a literature review method, analyzing journals, articles, and scientific publications to explore nanomaterials and biochar for efficient tofu wastewater treatment and improving water quality in Semarang City. Findings: The filtration system using biochar, CNT, TiO₂, and ZVI significantly reduces contaminants in water, enhancing water quality. Each material contributes uniquely, improving adsorption, photocatalysis, and overall filtration efficiency for heavy metals and organic compounds. Carbon nanotubes (CNTs), zero-valent iron (ZVI), and titanium dioxide (TiO2) exhibit high efficiency in environmental remediation, offering cost-effective, sustainable solutions despite challenges like toxicity and mobility. The study demonstrates the potential of nanomaterials like CNTs, ZVI, and TiO2 for enhanced environmental remediation, particularly in wastewater treatment. Their synergistic use improves contaminant removal, offering sustainable solutions with significant efficiency gains. Conclusion: In conclusion, integrating nanotechnology and biochar for tofu wastewater treatment presents a sustainable, scalable solution that advances both environmental remediation and technological innovation, aligning with SDGs and enhancing water quality management efforts. Novelty/Originality of this article: The novelty lies in combining nanomaterials and biochar for efficient tofu wastewater treatment, enhancing filtration and sustainability in water quality management

Comparison of combustion emissions between manual and machine set methods to reduce carbon monoxide (CO) in briquette manufacturing

Background: Renewable energy from biomass is one solution to reduce dependence on fossil fuels and the impact of carbon emissions. One form of renewable energy from biomass is briquettes. This study aims to analyze the effectiveness of using modern technology in the form of a briquette production machine set consisting of a grinder, extruder, and burner integrated with a wet scrubber innovation to reduce carbon monoxide (CO) emissions from rice husk combustion in the burner machine compared to the manual method. Methods: The research process was carried out through the stages of needs identification, CAD (Computer Aided Design)-based machine design, prototype production, and briquette performance testing using a Non-Dispersive Infrared (NDIR) analyzer. Findings: The test results showed that briquettes produced using the manual method had a higher density of 0.8 g/cm³ and produced an average CO emission of 220 ppm. These findings prove that mechanizing the process improves the physical quality of the briquettes while reducing CO emissions by around 39%. The integration of wet scrubber technology proved to be effective in absorbing additional exhaust gases and strengthening the environmentally friendly aspects of the combustion process. Conclusion: The conclusion of this study confirms that the use of integrated machinery not only improves briquette quality and energy efficiency, but also makes a significant contribution to carbon emission control efforts at the local level. Novelty/Originality of this Article: The novelty of this study lies in its comprehensive analysis comparing manual and mechanized methods using burner machines with integrated wet scrubbers in the context of rice husk briquette production

Strategi pengelolaan sampah kota terintegrasi menuju zero waste

The Sustainable Development Goals (SDGs), declared by 193 countries at the UN on September 25, 2015, serve as the foundation for global development. Building upon previous agendas, the SDGs emphasize three pillars of sustainable development: social, economic, and environmental. Cities, as centers of economic growth, face complex challenges in waste management. Urban waste, especially organic waste, requires special handling as it tends to decompose and create adverse environmental impacts if not managed properly. In the context of Indonesia, more than 65% of urban waste is organic, primarily food leftovers. To mitigate its impact, waste management is not sufficient merely with collection, transportation, and disposal at final disposal sites (TPA). Waste must be processed into useful goods, such as through recycling. This research proposes a Zero Waste approach to urban waste management. This concept involves waste prevention from the outset, reduction, reuse, recycling, and minimal waste residual management. Many cities worldwide, such as Canberra, Adelaide, and Stockholm, have successfully implemented Zero Waste strategies. In the Indonesian context, Surabaya is a successful example of effective urban waste management, involving various programs from waste banks to electricity generation from landfill gas. However, challenges in urban waste management persist. There is a need for new initiatives, such as involving more stakeholders from private to public sectors in the Zero Waste concept, and strengthening the government's role in implementing regulations supporting sustainable waste management. Additionally, education and public campaigns are crucial to raise awareness among the public about the importance of responsible waste management. Thus, this research highlights the importance of Zero Waste strategies in addressing urban waste management issues to achieve sustainable development goals

Spatial analysis of zinc (Zn) heavy metal distribution in the waters of Staring Bay, Southeast Sulawesi

Background: A spatial study of the distribution of heavy metal zinc (Zn) in the waters of Staring Bay, Southeast Sulawesi, has been conducted. This research aims to determine the spatial distribution of heavy metal Zn in the waters of Staring Bay. Methods: Sampling was carried out at 12 stations in the bay using a purposive sampling method. The concentration of heavy metal Zn in seawater samples was determined using an Atomic Absorption Spectrophotometer (AAS). Spatial analysis was performed using the Inverse Distance Weight (IDW) interpolation method (power = 2) with data processing software (ArcGIS 10.1). Findings: The results of the study indicate that the Zn metal concentration at the 12 research stations ranges from 0.0141 to 0.2085 ppm, with an average of 0.0668 ppm. The highest concentration of Zn metal is found at station 1. The results of the spatial analysis, with 12 stations, show that the area from the open sea to the coast of Tanjung Tiram Village has been contaminated with Zn heavy metal, ranging from 0.0132 to 0.2085 ppm. The same contamination is observed in the northern part of Wawosunggu Island, from the river mouth near Rumbia-rumbia Village to Lara Island, which has also been contaminated with a range of 0.0572 to 0.2085 ppm. Conclusion: Based on the contaminant factor (CF) values, the highest contamination by Zn metal occurs at station 1. Environmental variables (salinity, pH, temperature) show no significant effect on the concentration of Zn heavy metal. Novelty/Originality of this article: This study provides a comprehensive spatial analysis of zinc (Zn) contamination in Staring Bay, highlighting critical areas of pollution. It uniquely employs the Inverse Distance Weight interpolation method, revealing significant contamination patterns with minimal influence from environmental variables

Evaluation of waste composition for biochar production as a sustainable waste management approach

Background: To meet human life needs, fuel energy is obtained from fossil sources, such as coal, found in the Earth's crust. However, non-renewable energy sources in the Earth's crust will eventually run out. One alternative fuel is the production of biobriquettes from various types of waste. Methods: Using a literature review method, this study aims to determine which waste is most suitable for use in the production of biobriquettes. The samples taken are journals sourced from Google Scholar ranging from 2017 to 2022 that align with the discussion topic. Findings: Among various raw materials, the best waste for biobriquette production is found to be a mixture of dacron waste and corn cob, with a moisture content of 3.45% and a carbon value of 7986.45 cal/g. Conclusion: The results of the above study indicate that the production of biobriquettes from dakron waste and corn cobs is the best option because it yields the highest calorific value and the lowest moisture content, in accordance with SNI 01/6235/2000. Novelty/Originality of this article: This study presents a novel approach by identifying a specific combination of dacron waste and corn cob for biobriquette production, showcasing its superior calorific value and low moisture content, thus contributing to sustainable energy solutions and waste management practices

Microplastic as an written composition in bottled water: Implications for waste management

Background: Microplastics are the smallest particles of plastic measuring about 4.8 milliliters and are dangerous to the body due to the chemicals they contain, such as PCBs (Polychlorinated Biphenyls). Microplastics have been identified in various studies, both in aquatic and terrestrial environments, raising concerns about contamination in seafood, beverages (like beer), and more recently, bottled mineral water. Methods: This publication compiles and discusses currently available literature data on microplastic particles found in bottled mineral water. Findings: The discovery of microplastics in bottled mineral water highlights the widespread contamination of microplastics in consumable products, emphasizing the importance of water intake for supporting body metabolism. Conclusion: The identification of microplastics in bottled mineral water underscores the need for greater awareness of the dangers of microplastic contamination and its potential health risks. Novelty/Originality of this article: This article uniquely highlights the underexplored presence of microplastics in bottled mineral water, emphasizing the health risks associated with chemical contaminants like PCBs, and calls for increased awareness and regulatory measures to protect consumer safety