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Introduction: While many national-level governments have worked to tighten atmospheric air quality standard, the Authors observe, Indoor Air Quality (IAQ) control as part of building-codes have remained understudied and not yet enforced in many national-level regulations. The COVID-19 pandemic seemed to trigger an immediate response worldwide for IAQ control. Indoor air pollutants need to be tightly regulated. International agencies have produced recommendations to cope with the pandemic, however, national level IAQ standards and building codes have been slow to adapt. Materials and methods: IAQ regulations from various nations worldwide were studied along with the international standards: The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), and World Health Organization (WHO). A comprehensive review was conducted comparing the national-level building codes and regulations as legal implementation instruments. Focus group discussions were also conducted to complement preliminary findings and further analysis. Results: Except for Indonesia, bacteria and fungi have been categorized as infectious aerosols in many national-level regulations that fare up to the international standards as indoor air pollutants with their acceptable levels. However, while they set thresholds for pollutants, their effectiveness regulating IAQ in public buildings remain unknown. It also found that there is a significant lack of national building codes in Indonesia. Conclusion: The COVID-19 epidemic raises awareness of IAQ. The health aspect is currently being prioritized, particularly in Indonesia, where the majority of related regulations are still fragmented and prioritize energy conservation over health. This study can inform policymakers with evidence of IAQ control and practices worldwide for applicable regulatory building and implementation, as well as for health emergency and disaster risk management.

Religious nationalism is interpreted differently in its application in various countries. The purpose of this study is to explore the development of the meaning of religious nationalism values according to religious figures in Indonesia. The research method used to analyze social phenomena is a qualitative approach, using direct interviews and observations as the main data collection instruments. The essential results of this study are the values of religious nationalism must be preserved as a binder of social harmony since the formation of the Indonesian state. Religious figures view that the values of religious nationalism in Indonesia reject the secular state and the idea of an Islamic state (caliphate). The critical implication of this research is that religious figures promote the implementation of universal religious values in the public sphere and urge freedom of expression of religious activities democratically without discrimination for adherents of all religions.

Many efforts have been made to reduce the energy consumption of household refrigerators. One method is to place the pipe condenser to increase the rate of heat release. This numerical study examines the effect of changing the gap ratio on the flow characteristics and natural convection heat transfer of 20 pipes attached vertically to the convection plate with aluminum foil coating. The gap ratio was varied between 1.05 and 4.20 using ANSYS-FLUENT software to obtain velocity vector, temperature contour, tangential velocity, and local Nusselt number, both inside and outside the channel. With the change in gap ratios from 1.05 to 2.10, the rate of heat transfer increased significantly, reaching 2.2% while tangential velocity also increased considerably. At gap ratios of 3.15 and 4.20, the rate of heat transfer increased more gradually, local Nusselt number increased slightly where the influence of convection walls was smaller, and tangential velocity showed a very small increase. Flow characteristics were similar, with air flowing upward across the inner and outer channels.

Microalgae harvesting is the stage of any microalgae-based activity that is the most inhibiting, providing it with an interesting issue of investigation that could be used in the field. Electrocoagulation (EC) is an effective alternative harvesting method because EC produces high efficiency, ease of operation, fast harvesting, and adaptability. Furthermore, the harvesting of microalgae results in producing renewable hydrogen gas, an excellent option for generating clean energy and lowering greenhouse gas emissions. This study aims to assess the effectiveness of harvesting Chlorella sp microalgae by electrocoagulation using stainless still &iron electrodes. We measure optical density and quantification of dissolved hydrogen gas. Chlorella sp was harvested using EC by adjusting the electrolysis period for 30 minutes, voltage 15 V, and stirring at 400 rpm, Interestingly, the dissolved hydrogen gas in the initial Chlorella sp substrate was 0 ppb, then increased to 509 ppb after being electrolyzed for two minutes and 1214 ppb at 30 minutes. Statistically, electrolysis time significantly affected the increase in hydrogen gas concentration (α< 0.05). Electrolysis time of two minutes can harvest up to 90% Chlorella sp. Adding electrolysis time up to 30 minutes did not significantly increase harvesting efficiency.

Many household refrigerator owners do not control their thermostat settings. However, doing this could save energy consumption and also maintain the quality of stored food. This study presents the effect of regulated thermostat settings on household refrigerator energy consumption. The experiment was performed in a room chamber conditioned to temperature control at 25oC. A household refrigerator was used as a test unit, with a cooling load placed inside the freezer component. The cooling load used was an M-package, in accordance with SNI IEC 15502: 2008. The test results reveal that household refrigerator energy consumption increases with higher thermostat settings. Increases in energy consumption range from 17.10% to 18.65%, depending on the thermostat setting.

One of the environmental problems in Diponegoro University is waste, because the number of people is directly proportional to the amount of waste produced. According to the Minister of Environment Regulation number 13 of 2012, a waste bank is a place for sorting and collecting waste that can be recycled and/or reused which has economic value. This study aims to implement the waste bank program realizing management, analyze information system in the implementation of the waste bank program and optimizing the program of waste bank at Diponegoro University. Waste bank operations consist of weighing, recording, selecting the type of waste, requirements for waste conditions, working hours and a profit-sharing system. The waste bank information system implemented on the website. Waste bank optimization is carried out in development periods with a duration of 3 months each period.

Cooling towers are required in building HVAC systems that use water as the cooling condenser fluid. Cooling towers used in this study are of the forced draft, counter flow, indirect/closed evaporative type. This study sought to demonstrate the performance characteristics of a closed system cooling tower by its effectiveness value, Number of Transfer Units (NTU), cooling capacity, and overall heat transfer and mass coefficient of the cooling tower. Experiments were performed on a heat exchanger coil intercrossed with ? inch diameter intersections on parallel lines. Results of the experiment were then compared with the heat and mass transfer correlations taken from previous studies, and also combined with Computational Fluid Dynamics (CFD) simulations to examine the physical processes that occur in the cooling towers. All the experimental results, theoretical calculations and CFD simulations used variations of warm water mass, cold air, and water spray to present a clear description of the performance characteristics of a closed system cooling tower. The results of this study have shown that an increase in the amount of water spray mass flow causes an increase in the effectiveness value, heat transfer and overall mass transfer, as well as the cooling capacity of the cooling tower. The waste heat typically utilizes up to 80% of latent evaporation heat, and 20% of sensible air heat; however, waste heat in the closed system cooling tower utilizes 100% of latent evaporation heat. The mass transfer coefficient rate tends to be stable for a small mass of water spray.

Currently, Diponegoro University has been composting dry leaves with conventional methods through a facility called TPST. Even so, the processing which have been carried out has not been able to process all the organic waste in the location. Seeing these conditions, it is necessary to look for alternatives that are better and more economical to apply. Bioactivators are used from the leaves of Pterocarpus indicus which serve to accelerate the composting process. The bioactivators was made by making a solution of the leaves of Pterocarpus indicus which has been mashed, then mixed with molasses and rice flour and then left for 15 days. By using experimental method, the composting process is observed. This study aims to analyze the quality of compost with applicable standards. The quality of compost is assessed by looking at the pH, temperature, and macro nutrient percentage such as C-organic, N-total, and C / N ratio. During the composting process, variations in the stirring frequency are carried out, which is once every 2 days, 4 days and 7 days. After doing laboratory test, not all reactors meet the standards for pH, temperature, C-organic, N-total, and C / N ratio according to SNI 19-7030-2004.

In some areas, compacted clay liner is chosen as leachate barrier for solid waste landfill. Due to the typical shape of the landfill, the compacted clay liner will be rested both in flat and sloping ground. Since clay has characteristics of low shear strength, improvement of shear stability of compacted clay liner is required. One of the stability methods to increase the shear strength of clay is by adding another material which has higher shear stability. In this study, bentonite is used to represent clay liner while zeolite is utilized as stabilizer material. Four compositions of bentonite with 0%, 5%, 10%, 15% addition of zeolite were prepared to investigate the stability performance of the mixtures. The results indicate that the addition of zeolite into bentonite has increased the friction angle of the bentonite. However, the addition of zeolite seems to alter the hydraulic performance of bentonite. The highest permeability is demonstrated by the bentonite with 15% of zeolite. Whether the permeability increases, the hydraulic performance of all the mixtures are still met the maximum permeability allowed for landfill liner.

Domestic waste from households is the biggest contributor to municipal waste management. Palangka Raya City is one of the cities that faces waste problems due to lack of awareness of the citizens. The culture of dumping garbage into river bodies is common for residents who live along the river banks. This study aims to determine waste generation and the factors affecting waste generation of household in the Palangka Raya City. The measurement of waste generation was carried out in accordance with the guidelines of SNI 19-3964-1994, while the variables that are suspected to influence the waste generation were collected by the questionnaire. To find out the factors affecting waste generation, data were analyzed by multiple linear regression. Based on the results of research conducted on 48 respondents obtained household waste generation in Palangka Raya City is 0.33 kg/person/day, while significant factors affecting waste generation are concern for the environment and income levels at a 95% confidence level and the number of family members at the 99% confidence level. While the recycling knowledge, education level, house size and installed electrical power did not significantly affect waste generation. With this information, it can be calculated the needs of TPS, the needs of the transport fleet, the needs of cleaning staff and plans for controlling household waste generation in the Palangka Raya City.

Energy balance analysis study for the production process of biodiesel needs to be done to find out whether a production process of biodiesel activity has a surplus energy or minus energy. This study aims to analyse the balance of energy of the plantation of palm, production of palm oil, and production process units of biodiesel with the life cycle assessment in Banyuasin - Indonesia. The results of this study indicate that the largest energy input in the plantation of palm, production of palm oil, and production process units of biodiesel sequentially is the use of urea as N-fertilizer, electricity, and methanol. The value of NEB and NER in the production process of palm biodiesel sequentially is 5871 MJ and 1.17. Finally, the production process of palm biodiesel in Banyuasin area has a positive energy balance. The activity of production of palm biodiesel is proper to operate because it produces an energy surplus.

Green campus is a concept, which integrates environmental science into policy, management and activities of the college. Green campus is also the implementation of the integration of environmental science in all aspects of management and sustainable development practices. Therefore, the standards for referral and encouragement to management in developing a green campus program are needed, one of which is UI GreenMetric. The purpose of this study are to determine how the program of UI GreenMetric is implemented at Diponegoro University and to provide recommendations in the category or indicator that has not been fulfilled. Optimizing the implementation of UI GreenMetric can be used as a further reference in the development of green campus concept in Indonesia. This study uses data in the form of a literature study of standards and guidelines used by UI GreenMetric which are considered in accordance with the strategy of increasing effectiveness in implementing green campus. The results showed the value obtained by Diponegoro University in the UI GreenMetric World University Rankings standards.

The waste generation increases along with the increase of population and then the percentage of waste services is increasing every year so the capacity of Sukoharjo landfill becomes decreasing. While to find a suitable location for new landfill sites that are completed requirements of regulation is difficult. It is needed some actions to extend the lifetime of Sukoharjo landfill, one of them is application 3R (Reduce, Reuse, Recycle) mechanism in waste management. This study aims to analyze the lifetime of Sukoharjo landfills with the mechanism of Reuse, Reduce and Recycle (3R). The method used in this research is quantitative and qualitative methods. Based on the calculation, the landfill only available until 2022. The existence of composting and recycling of anorganic waste, landfill lifetime will extend until 2025. Our results show that there is a significant comparison of the volume waste in landfills between untreated incoming trash with treated by Reduce, Reuse, Recycle (3R) mechanism. By 2028, the waste generation in a landfill will be 24,821,724 kg. During composting (30%) and recycling of anorganic waste (15%), the volume of waste in landfill is reduced to 14,401,796 kg.

Managing a modern university that applies various international standards (world class university) must pay attention to many important factors, including sustainability. Universitas Diponegoro (Undip) Semarang, Indonesia as a public university legal entity that also has a vision of becoming a research university is well aware of the importance of establishing sustainable campus. This paper describes sustainability program of Undip called UNITY, which stands for Undip Initiative for Sustainability. This program refers to five main factors, namely infrastructure, energy and climate, waste, water, and transportation. This paper briefly discuss planned activities of each factor. The program which is fully supported by all components of Universitas Diponegoro, aims to create a campus that is clean, healthy, comfortable, safe and sustainable.

One of the results of the water treatment process is the sludge. Generally, the processed sludge from the water treatment is collected and delivered to a landfil. With the delivery of sludge waste, it requires additional cost as a levy in handling sludge waste. Therefore, it is needed to innovate on the recycling of sludge. The waste recycling process is expected to minimize the residual impact of the Water Treatment Plant. The process of waste recycling can be done by utilizing sludge from water treatment, which is brick making process. The benefits can eliminate environmental problems and also some economic problems. This study aims to determine the potential of sludge from water treatment plant to be added for brick making by investigating the physical and characteristics of sludge. The research findings show that sludge waste has the potential to become a brick raw material depending on the nature and clay microstructure

Kegiatan ini bertujuan untuk membantu menyelesaikan rendahnya produktvitas UKM pengrajin tas œENDXEN dan tas œSYAFAAT di Gresik. Permasalahan urgen yang harus segera diselesaikan dalam upaya meningkatkan produktivitas kedua UKM pengrajin tas ini adalah perbaikan teknologi produksi melalui penerapan teknologi tepat guna (TTG) berupa mesin jahit elektrik untuk menggantikan mesin jahit manual. Metode untuk mengatasi permasalahan tersebut dilakukan melalui penerapan mesin jahit elektrik melalui kegiatan pelatihan dan pendampingan. Berdasarkan hasil kegiatan yang telah dilakukan maka dapat diketahui bahwa pengusaha kecil pengrajin tas ini telah dapat meningkatkan produktivitas produksinya dan karyawan meningkat penghasilannya, yakni untuk jenis tas rangsel laptop dari 7 tas/hari menjadi 14 tas/hari sehingga ada peningkatan produksi 100% dan upah untuk satu tas rangsel Rp.8.000 sehingga penghasilan karyawan meningkat dari Rp.56.000 menjadi Rp.112.000, dan untuk jenis tas sekolah dari 12 tas per hari menjadi 30 tas per hari, sehingga ada peningkatan produksi 150% dan upah untuk satu tas sekolah Rp.4.000 sehingga penghasilanya karyawan meningkat dari Rp.48.000 menjadi Rp.120.000.

The durability and strength of concrete in construction can be significantly compromised by permeability issues, which pose considerable challenges to its long-term effectiveness and reliability. By analyzing six selected articles from the Scopus database, this study meticulously synthesizes findings on the effectiveness of CAs in improving these essential properties of concrete. The research meticulously documents and analyzes key variables such as the CA dosage, water–cement ratio, evaluation duration, and treatment conditions, providing a thorough understanding of the factors that influence the performance of CAs in concrete. The results robustly indicate that CAs significantly reduce concrete permeability, thereby enhancing its resistance to water and other detrimental substances, and simultaneously boosts the compressive strength, leading to stronger and more durable concrete structures. However, the study also reveals that the impact of CAs can vary considerably depending on the specific conditions and methodologies employed in the individual studies. This underscores the importance of standardized testing procedures to ensure consistent and comparable results across different studies. This research provides valuable insights for optimizing the use of CAs in concrete formulations, ultimately aiming to improve the durability, performance, and sustainability of concrete in construction applications. [ABSTRACT FROM AUTHOR]

The rainwater that reaches the ground will enters the soil (infiltration) and some water are not absorbed by the soil will become surface runoff. The regional development tends to change water catchment areas by changing land functions and affecting surface runoff. The regional development in Kalibenda Village has cause problems related to the local community water supply. In 2019 some of the local community in Kalibenda Village have experienced difficulties in accessing clean water supply which has never happened in the past . This study provides an analyze of the impact of land use changes that occur in Kalibenda Village on surface runoff. This study uses a Rational method to calculating runoff discharge by using elevation profile analysis tool from Google Earth program to calculated sloop, Approb_4.1 program to process rain data and ArcSwat Tools in the ArcMap 10.2 program to water catchment analysis. The study results shows that Kalibenda Village divided into 6 (six) catchment water. There has been increased runoff from 2000 to 2021 by 6.44%. The most influential factors are changes in land cover change from rice fields to settlements, plantations and meadow grass.

In Indonesia, transportation sector, specifically road transport consumed most energy compared to other sectors. Eventually, the energy consumption will increase due to the growth of vehicle number that also escalate emission. Vehicle emissions had been recognized as a significant contributor to atmospheric greenhouse gas (GHG) pollution. Heavy-duty vehicles are considered as main sources of vehicular emissions in most cities. Therefore, it is crucial to take into account heavy-duty vehicle emission projections in order to support policymakers to identify vehicle emissions and develop pollution control strategies. The aim of this study is to forecast heavy-duty vehicle population, vehicle kilometers travelled (VKT), fuel consumption, and heavy-duty vehicle emissions using data of Semarang City to illustrate greenhouse gas emission of big cities in Indonesia. Business as Usual (BAU) and The Intergovernmental Panel on Climate Change (IPCC) method were incorporated to determine vehicle emission projection. Heavy-duty vehicle emissions increase from 2021 to 2030 by 12.317 to 22.865 Gg CO2/year with amount trucks and buses emissions of 21.981,5 Gg CO2/year and 884,2 Gg CO2/year, respectively.

Food waste needs to be processed immediately after disposal, because it causes leachate and unpleasant odors. The purpose of this study was to utilize food waste using a rotary kiln composter. Food waste was chopped and placed into a rotary kiln composter equipped with an aeration system (6 L/min), stirring mechanism, and remotecontrol functionality via mobile phone for automated operation. Further, a bulking agent was added with a ratio of food waste vs bulking agent of 70:30. The addition of microorganism mass was varied to speed up the composting process for 14 days. The results showed that the compost derived from food waste was stable within 3 days. The temperature of the food waste matrix reached 46 °C, and the pH value of the compost was close to neutral since day 4. In this study, no leachate was produced, either R1, R2, R3, or R4. The final total organic carbon (TOC) content was 12.12-15.22%, Total-N was 0.83-1.04%, phosphorus was 0.18%, and potassium was 1.05%. On the basis of the C / N value and the germination index (GI), the R2, R3, and R4 reactors produced mature and stable compost on the third day with C/N values < 20 and GI > 100%. This result is a good breakthrough because the rotary kiln composter can accelerate the composting process of food waste within 3 days. [ABSTRACT FROM AUTHOR]

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Agricultural waste recycling is crucial for sustainable farming operations and farming practices. Life cycle assessment has emerged as an innovative and comprehensive viewpoint that considers the entire recycling process to evaluate the potential and true implications of agricultural waste recycling. This study considered methods for recycling different agricultural waste streams, such as crop waste, animal manure, pruning materials, and by-products and subsequent uses. Furthermore, the life cycle assessment method was used to investigate the process of handling agricultural waste, from collection and recycling to final usage in the agricultural system. Environmental impact categories, including greenhouse gas emissions, energy usage, eutrophication, acidification, and land use, were evaluated to determine their potential effects on climate change, resource depletion, and ecosystem health. The results were compared with those of 31 studies that analyzed the potential environmental impacts of agricultural waste management. Various methods initially developed and implemented for agricultural waste landfilling methods have now changed to energy-generating sources, such as biochar, biogas, briquettes, and various energy production methods. Furthermore, composting, a popular method of recycling agricultural waste, significantly lowers greenhouse gas emissions and energy use compared to traditional waste disposal techniques. The study also examines cutting-edge technologies, such as anaerobic digestion and biomass-to-energy conversion, highlighting their potential to manage agricultural waste and being a sustainable energy source. These findings indicate potential environmental advantages in terms of decreased greenhouse gas emissions and fossil fuel consumption, leading to a circular economic approach for agriculture. When integrating agricultural waste, including composting, anaerobic digestion, and pyrolysis, biochar is highlighted as a waste recycling method that is promising for sustainable waste management. In addition to efficiently managing agricultural waste, these technologies help generate electricity and sequester carbon, thereby advancing the objectives of climate change mitigation and circular economy. Although life cycle assessment has been used to analyze several waste management strategies, including those specific to agricultural waste, certain significant gaps and discoveries still require attention for a more thorough analysis. It might be challenging to gather complete and accurate data to assess the entire lifecycle of agricultural waste management technology. The direct environmental effects of waste management are frequently the focus of life cycle assessment studies, but they may overlook secondary effects such as indirect land use change, habitat damage, and biodiversity effects. It is crucial to consider these secondary effects in a more comprehensive analysis. [ABSTRACT FROM AUTHOR]

Water has recently become a final disposal site for wastewater. Land use has evolved with the global population growth and is generally transformed into settlements and industrial areas. These land use changes could potentially increase wastewater generation from both domestic and non-domestic activities. The Garang watershed, one of the watersheds in Central Java, flows through the Semarang Regency, Kendal Regency, and Semarang City. This study analyzed the water quality conditions in the Garang watershed and designed a real-time water quality monitoring system. The methods used in this study included SWMM modeling, the national sanitation foundation water quality index (NSF-WQI), and the internet of things. Samples were collected from 10 points in the Garang Watershed, with a sampling frequency of five times at each point. The results of the data analysis demonstrated that the differences in land use resulted in varying water parameter levels. The results of the SWMM modeling demonstrated an acceptable model value (NOF between 0 and 1). On the other hand, the WQI analysis results demonstrated that the quality status at the Garang watershed is "medium" at nearly all location points. The designed real-time water quality sensor tool successfully transmitted water quality data online and in real-time, particularly for temperature, pH, turbidity, and DO. This water quality monitoring system offers a variable percentage error value, with the pH sensor ranging between 0.16% and 9.86% and the temperature sensor ranging between 0.64% and 1.72%. [ABSTRACT FROM AUTHOR]