bluuebunny/crossref_metadata_2025 huggingface dataset:
A study on the implementation of a circular economy in municipal solid waste management in the new capital city of Indonesia
Authors: Otivriyanti G , Fani A M , Yusuf N R , Haris K A , Alfatri P , Purwanta W
Published: June 2023

The new capital city of Indonesia is designed with the concept of a smart and sustainable city where waste management will implement a smart trash system with the concept of a circular economy. The key performance indicator (KPI) for waste management are 60% recycled and net zero emission. The waste management system is based on a projected population of 276,125 people in 2045 with a waste generation rate of 0.7 kg/cap/day. In this study, the calculation of KPI fulfillment was carried out in two scenarios. In the first scenario, 31 tpd of inorganic waste will be recycled, while 32 tpd of waste and 15 tpd of sludge will be processed in a waste-to-energy (WtE) incinerator. The second scenario is if the recycling ecosystem has not been established, the combustible waste will be burned in the WtE incinerator while the incombustible waste will be landfilled. WtE incinerator with a capacity of 2x50 tpd with an electrical output of 2x250 kW will recycle waste into energy. The global warming potential of both scenarios is negative, which means there is a net zero emission. Based on this study, both scenarios can meet KPI and have the potential to implement a circular economy.
The challenges in sustaining waste banks in Serang City: How far the circular economy can go?
Authors: Pratama R A , Wahyono S , Sahwan F L , Suryanto F , Suprapto  , Tilottama R D , Parlina I , Prasetiyadi  , Diyono  , Sarkiwan  , Arreza G
Published: June 2023

The existence of a waste bank is designed to reduce the municipal waste problem. However, not all regions can implement the waste banks program to deal with municipal solid waste. In 2019, Serang City managed only 51% of municipal waste out of 155,490 tons of waste/per year, including the contribution from the waste banks. This study aimed to determine the challenges of implementing waste banks and the impact of the circular economy in Serang. This study used a mixed approach which describes the results qualitatively-quantitatively. The study found: the positive response of the community to the existence of waste banks, the environmental motive behind the establishment of waste banks, waste banks in Serang dealing with infrastructures, human resources, and management, and the basic business model. Waste banks economically had not made a significant contribution to the members. The reduction ability was only 0.03% of total municipal solid waste. Another problem encountered was that cooperation with off-takers was not done on a contractual basis, which led to uncontrolled prices.
Potential quantity of liquid fuel from pyrolysis of plastic waste in Labuan Bajo
Authors: Haris K A , Tilottama R D , Robbani M H , Yuliani M
Published: June 2023

Labuan Bajo is one of the super-priority tourist destinations expected to attract more international tourists to increase foreign exchange. To make this a reality, a combination of programs that support tourism and master plans, including solid waste management, is needed. Private sectors have developed a circular economy to handle the plastic waste. However, this plan is constrained by the high cost of transporting plastic waste to recycling factories. Pyrolysis technology can be an alternative to treat solid waste without transporting it outside Labuan Bajo. A study of pyrolysis technology is needed before it can be applied, including the quantity of liquid fuel produced by the pyrolysis process. This liquid fuel can be utilised to fulfil the community demands, such as the demand for engine fuel. This research aimed to ascertain the potential quantity of liquid fuel produced by the pyrolysis process using plastic waste from Labuan Bajo. The calculation was carried out using two different scenarios: developed predictive theoretical model conversion and installed full-scale pyrolysis plant yield. The potential quantity of liquid fuel produced using the scenarios above is in the range of 3,075–2,763.83 L/day and can potentially supply 3.24–2.91% of Labuan Bajo’s liquid fuel demand.
Simulation of neutron shielding performance of Al-Cd alloy for radioactive waste container
Authors: Heriyanto K , Sudjadi U , Artiani P A , Rachmadetin J , Setyawan D
Published: June 2023

Neutron shielding material is necessary for the container of radioactive waste emitting neutrons, such as spent fuel from research reactor. This study aimed to determine the shielding performance of Al-Cd material for neutron radiation emitted by radioactive radiation. The calculations of neutron shielding were carried out using MNCP5 software. The Al-Cd shielding was simulated to withstand a neutron radiation source with 2.538×10−8 MeV energy and 4.5 MeV energy moderated with paraffin. The Al-Cd was simulated as a homogeneously-mixed alloy and Al coated with Cd. The results show that addition of Cd to Al increased the neutron shielding performance for thermal and fast neutron. With the addition of 10% Cd to Al, the neutron shielding performance increased by more than 90% for thermal neutron, and 30% for fast energy neutron moderated with 5 cm thick paraffin. It shows that Al-Cd alloy is potential for radioactive waste container which requires high neutron shielding performance.
Multi-criteria analysis for solid waste management system in Indramayu coastal area
Authors: Nurjayati R , Widyarsana I M W , Kurniasari O
Published: June 2023

Coastal area pollution in Indonesia does not only occur in one area but is spread over several points on the coastline of the Indonesian archipelago. Indramayu Regency, one of Indonesia’s coastal areas with significant marine resources and tourism assets, has experienced a worsening solid waste problem. This research activity was carried out in Cantigi District and Indramayu District; both areas were considered capable of representing the condition of Indramayu Regency which has various regional conditions but generally has resources and tourism assets in coastal areas. The analytical hierarchy process (AHP) is a decision-making model with multiple criteria that involves several alternatives that are selected based on consideration of all related criteria. In the analysis, five aspects became criteria: environmental, financial, social, technical, and institutional. This study aimed to formulate a solid waste management system in Indramayu Regency with the AHP approach. The study results are recommendations for solid waste management system alternatives that involve collaboration between the community and the regional technical implementation unit (UPTD). The alternatives are optimizing the function of the temporary waste shelters for waste reducing, reusing, and recycling (3R TPS) and socialization to the community about sorting waste activities.
Effect of rainfall on assessment of hydrologic sustainability in Citanduy sub-watersheds
Authors: Pramono I B , Basuki T M , Auliyani D
Published: June 2023

Hydrology is one of the criteria for monitoring and evaluation (monev) of watersheds management as stated in the Minister of Forestry Regulation Number P.61/Menhut-II/2014. So far, the use of various hydrological parameters for the monev of watersheds has not been evaluated whether these parameters truly reflect the condition of the watershed. This study aimed (1) to evaluate the effect of rainfall on the hydrological criteria of each sub-watershed, which include: flow regime coefficient, annual flow coefficient, sediment load, and water use index and (2) to evaluate the effect of rainfall on watershed carrying capacity. Regression analysis was used to see the relationship between annual rainfall and hydrological parameters used in watershed sustainability. This analysis was crucial to see the development of forest and land rehabilitation efforts in restoring degraded land. Data collection was carried out from 2008 to 2016 in each of the sub-watersheds of the Citanduy Watershed, namely Cijolang, Cikawung, Cimuntur, Ciseel, and Upper Citanduy. From this research, it is known that flow regime coefficient, annual flow coefficient, sediment load, water use index, and flood frequency are strongly influenced by rainfall so the result in evaluating watershed carrying capacity may vary depending on the rainfall. Besides being influenced by rainfall, flow regime coefficient, annual flow coefficient, and sediment load are also affected by land cover, while the slope affects the sediment load.
Benthic macroinvertebrates community to response environmental factors in a crater lake (Case study: Lake Menjer, Indonesia)
Authors: Imroatushshoolikhah  , Subehi L , Suryono T , Yoga G P , Sudarso J , Sari L , Ibrahim A , Samir O , Rustini H A
Published: June 2023

Lake Menjer is one of the crater lakes located in the highland of Central Java, Indonesia, which has received multiple stressors from anthropogenic activities. Benthic macroinvertebrates as a key indicator for water quality were little known there. Thus, this present research aimed to identify benthic macroinvertebrate structures and to understand the response of this community to water quality in Lake Menjer. Samplings were conducted twice, one week each in August and October 2019 at five sites. Sampling in August represented the condition of the dry season, while in October represented the rainy season. Some groups were identified into the family and others into the genus level. Water quality variables were measured directly on the site, including water clarity, pH, dissolved oxygen (DO), conductivity, total dissolved solids (TDS), and oxidation-reduction potential (ORP). Meanwhile, the level of total nitrate (TN), total phosphate (TP), nitrite, and chlorophyll-a were analyzed separately. A total of 4312 benthic macroinvertebrates composed of eleven taxa belonging to eight families were recorded, namely Chironomidae (22.85%), Tubificidae (73.50%), Lumbricullidae (0.68%), Thiariidae (0.21%), Planorbidae (0.45%), Lymnaeidae (0.21%), Unionidae (0.92%), and Corbiculidae (1.13%). The number of taxa varied between 1 to 3 in each station. Mollusk was the best-represented group with five families. Meanwhile, Tubificidae was shown as the predominant family in abundance both in August (3879 ind/m2) and October (2008 ind/m2). Shannon-Wiener index ranged nearly similar between the two seasons, 0.17 to 0.91 in August and 0.0 to 0.91 in October. ANOSIM CAP6 result illustrated that there was an insignificant difference in benthic macroinvertebrates abundance (P below 0.05) among sampling sites in Lake Menjer. This community was mostly homogenous. Bray-Curtis analysis using MVSP shows similarities in the taxa compositions between the sites. The analysis between water quality and macroinvertebrates which was performed by Canonical Correspondence Analysis shows that nine taxa tended to correlate with the level of TN, DO, and conductivity. Meanwhile, the other two taxa had a relationship with water clarity, temperature, level of TP, nitrite, and chlorophyll-a.
Groundwater nitrogen concentration changes in an urbanized area of Indonesia over ten years period
Authors: Rusydi A F , Setiawan T , Maria R , Firmansyah F , Damayanti R , Mulyono A , Rahayudin Y , Bakti H , Perdananugraha G M , Carrilo-Rivera J J
Published: June 2023

Nitrogen in groundwater poses environmental concerns in Bandung Region, Indonesia, due to natural and anthropogenic factors. The predominant component of the region’s aquifer is high-hydraulic-conductivity volcanic rock, one of the natural vital factors that make the aquifer vulnerable to contamination. Another factor is urbanization which has been reported to be an adverse effect of high nitrogen levels in the groundwater, particularly the unconfined system. This study’s objective was to evaluate urbanization’s impact on dissolved inorganic nitrogen concentrations over a 10-year period, which had not been explained by previous research. The evaluation focused on land-use changes in the southern part of the Bandung Region and their relation to dissolved inorganic nitrogen (DIN) in unconfined groundwater. A total of 88 samples were collected in 2009, 2015, and 2018 from three types of land-use: residential, plantations, and paddy fields. From 2009 to 2018, land use changes were visible, with an 8% and 6% increase in urban settlements and rice fields, respectively, and a 15% reduction in plantations. Furthermore, over a decade, agricultural and rice fields substantially impacted the NO3
− levels, contributing approximately 13.2 mg/L and 9.9 mg/L, respectively. In the meantime, the settlement area significantly contributed to the 3.25 mg/L increase in the NH4
+ levels.
Identifying environmental variables in potential flood hazard areas using machine learning approach at Musi Banyuasin Regency, South Sumatra
Authors: Handika R , Pratama R A , Ihsan I M , Adhi R P , Sabudin  , Sundari A , Sulistiawan I N , Nugraha Y W
Published: June 2023

Meteorological natural disasters are related to climate. Anomaly conditions in warm sea surface temperatures cause the water vapor to overflow into rain-forming clouds, gradually forming high integrated rainfall in some areas of Indonesia. High or extreme rainfall causes a hydro-meteorological disaster in the form of a flood. Musi Banyuasin Regency, South Sumatra, has a concave to flat topography, a swamp area with abundant large and small rivers prone to flood disasters. Between 2012 and 2022, the National Disaster Management Agency (BNPB) recorded 38 locations had been flooded. This study aimed to identify environmental variables that affect the potential flood hazards and areas with a high flood hazard level. This study used a maximum entropy model approach based on machine learning techniques. The model analyzed all the findings in the sample data to produce predictive information on the contributing environmental variables. The sample data was the 38 flood areas with each preliminary fact and topographic characteristic. Threat components were arranged based on environmental variables (aspect, slope, elevation, land cover, rainfall, and distance from the river). The results indicate that contribution of the average rainfall was 58%, elevation was 26.4%, slope angle was 8.6%, slope aspect was 5.8%, land cover was 1%, and river width was 0.1%. Then, the areas with high flood hazard levels were indicated in eight districts, namely Lais, Sekayu, Babat Supat, Keluang, Sungaililin, Lawang Wetan, Babatoman, and Sangadesa.
Application of PeCOD and dichromate methods for the analysis of chemical oxygen demand (COD) in the wastewater sample
Authors: Rosmalina R T , Wulan D R , Widyarani  , Hamidah U , Hidayat  , Azman S
Published: June 2023

Chemical oxygen demand (COD) is one of the critical environmental parameters in determining the organic matter in water matrices. The conventional dichromate method employs hazardous reagents and heat reflux. In order to reduce hazardous waste, several alternative methods have been proposed to replace the dichromate. The photoelectrochemical COD (PeCOD) method has become a promising one for being less time-consuming, environmentally friendly, and more reliable. To ensure the result, a comparison between PeCOD and dichromate methods should be conducted. In this study, we analyzed the technical features of the PeCOD method, especially for the accuracy in measuring certified reference material (CRM), and identify the advantages and disadvantages of this method. Afterward, we applied both PeCOD and dichromate methods to analyze tofu processing wastewater as a representative of environmental samples. The result showed that PeCOD gave a recovery of 113.1±4.8% whereas the dichromate method gave a recovery of 98.4±1.7%, which indicates that the PeCOD method had lower accuracy than the dichromate method. Meanwhile, the COD concentration of tofu processing wastewater using PeCOD and dichromate methods was 11516±669 mg/L and 9109±680 mg/L, respectively. This difference might be due to overestimation by the PeCOD method, the complex matrix of the wastewater, and chloride interference.
Mercury content in mining waste and its effect on the surrounding environment (Case study: Small-scale gold mining locations-West Sumbawa)
Authors: Garinas W , Hidayaturahman H , Majalis A N
Published: June 2023

This study was conducted to determine the content of mercury in the flowing river around small-scale gold mines. Mining wastes from the run of mining are dumped into the watersheds and potentially contaminate the water and sediment in the watershed near the gold mining area. We analyzed the characteristics of the waste and the result was compared with the water quality standards (Environment Minister Decision No.202 of 2004 and Government Regulation No.82 of 2001) and sediment quality standard (the Canadian sediment quality guidelines for the threshold effect level (TEL) and probable effect level (PEL)). We found that wastewater from the gold mining areas was categorized in class IV. The mercury content in the sediment samples did not meet the standards of Canadian sediment quality guidelines for TEL. The content of mercury in the sediment samples from the gold mine site was very high. The sediment mercury samples had been settled for a long time around the watershed. The content of mercury in the mining location indicated that mercury had been contaminating the area around the small-scale gold mining.
Water Quality Data Analysis from the Onlimo Monitoring System at 16 Stations in Priority Watersheds and Lakes
Authors: Yudo S , Wahyono H D , Alhasa K M , Warto  , Zulaikha S , Pandiangan Y S H
Published: June 2023

Currently, the decline in the quality of river and lake water continues, for this reason, activities to control pollution and improve river and lake water quality are required. One effort to prevent this problem is to implement online water quality monitoring technology continuously and in real time. The information generated from the water quality monitoring system can be used as a basis for planning watershed management and determining river and lake water management policies at the national and regional levels. The purpose of this activity is to analyze river and lake water quality data and evaluate the performance of the monitoring systems in 16 water quality monitoring stations that have been built. The data being analyzed is from 2016 to 2020 and includes the parameters of temperature, conductivity, TDS, DO, pH, and turbidity. The 16 station locations are spread over the Ciliwung River, Cisadane River, Citarum River, Serayu River, Bengawan Solo River, and Lake Toba. This research method uses descriptive statistical analysis and the STORET method, which refers to the Decree of the Minister of Environment and Forestry Number 115 of 2003 and Government Regulation of the Republic of Indonesia Number 82 of 2001. The results of this study indicate that most of the rivers monitored fall into the moderate to heavily polluted category, especially the rivers downstream of the Ciliwung, Cisadane, and Bengawan Solo rivers. The results of the analysis of DO, TDS, conductivity, and turbidity parameters from 16 monitoring stations, mostly met the Class II quality standards.
Microplastic occurrence and characteristics in a municipal wastewater treatment plant in Jakarta
Authors: Setiadewi N , Henny C , Rohaningsih D , Waluyo A , Soewondo P
Published: June 2023

Wastewater treatment plants (WWTPs) can act as both a barrier but also as an entrance route for microplastics (MPs) into aquatic environment. This study investigated the first occurrence and characteristics of MPs in Setiabudi Jakarta WWTP. Sampling technique, extraction methods, and quantification as well as characterization of MPs was carried out based on some related previous studies. The results showed that MPs concentration detected in the influent was 17.1 (± 5.65) items/L, and it was reduced to 1.41 (± 0.01) items/L in the effluent, indicating that approximately 91.29% of MPs in raw wastewater was removed during the treatment. Based on the daily effluent discharge, it is estimated that around 352.5 of MPs are released from the WWTP each day. The light microscopic method used for quantification and characterization revealed that MPs was widely distributed in the 100–5000 μm range. The color of MPs in both influent and effluent was mainly composed of white or transparent (35%) and black (17–25.4%). Based on shape category, fibers (68–70.17%) are the dominantly found in two sampling points, followed by fragments (23.68–26.24%), films (0.71–2.9%), microbeads (0.4–1.4%) and foams (1.4–2.8%). Our findings demonstrates that the presence of Setiabudi WWTP can significantly reduce the MPs pollution from raw wastewater, however, MPs discharged into the environment was still considerably high.
Study on properties of rigid polyurethane foam as a thermal building insulator at varied mixing conditions
Authors: Rifathin A , Dara F , Novriadi D , Radini F A , Vicarneltor D N , Burhani D , Sondari D , Septevani A A
Published: June 2023

The concept of zero-energy building is one of the promising ways to improve energy efficiency, resulting in the reduction of greenhouse gas emissions. The use of rigid polyurethane foam (RPUF) has been widely used as insulation material in building panels because of its excellent properties including light-weight, durability, and lower thermal conductivity. This study aimed to determine the effect of mixing conditions on the production of RPUF at varied mixing speeds (300, 500, 1000 rpm) corresponding to its density, mechanical, and insulation properties. It was observed that the well-defined physical structure of RPUF was obtained at the minimum mixing speed of 500 rpm. The foam density changed with the increasing mixing speed, from 39.8 kg/m3 at 500 rpm to 51.30 kg/m3 at 1000 rpm. This might be because of the possible loss of the blowing agent due to excessive mixing speed as noted by the constrained foam expansion and the shorter time for the free-rise process. The thermal insulation property of obtained RPUF was significantly lower than that of conventional building materials like concrete. This research is one of the key technologies to reduce the energy consumption for heating-cooling buildings and thus create a potential strategy for climate change mitigation.
Analysis of net-zero emission index for several areas in Indonesia using individual carbon footprint and land use covered
Authors: Mawardi M I , Winanti W S , Sudinda T W , Amru K , Saraswati A A , Sachoemar S I , Arifin Z , Alimin A
Published: June 2023

The issue of global warming continues to be a concern for the international world. One of the causes of global warming is the greenhouse gas (GHG) effect caused by an increase in the amount of emissions in the atmosphere. Indonesia has set targets for reducing GHG emissions in the Nationally Determined Contribution (NDC) by 31.89% on its own capability and 43.20% with international assistance in 2030. Therefore, to support the program, it is necessary to conduct research to inventory the emissions produced and emissions absorbed by each region in Indonesia. This study calculated the net-zero emission index in an area by comparing the value of carbon emission with the value of carbon sequestration based on land cover in an area. Regional emission data was obtained from Aksara Bappenas, while regional sequestration data was obtained from RAD-GRK and satellite imagery interpretation based on land cover. Meanwhile, to calculate emissions at the city/regency level, individual carbon footprint data was used and converted into city/regency emission data. The calculation of the carbon index was carried out nationally in all provinces of Indonesia. Several provinces were further tested as examples to determine sequestration based on land cover from imagery interpretation. The results show that the Indonesian net-zero emission index is lower than 1, but some provinces with dense populations have a net-zero emission index >1, namely: DKI Jakarta, DI Yogyakarta, North Sumatra, and Riau.
Exploring household flood resilience index using composite indicator method
Authors: Santosa B H
Published: June 2023

During a flood event, flood-affected households need adequate flood resilience. The efforts to increase household flood resilience require an adequate understanding of the factors affecting household flood resilience. This study aimed to explore the factors influencing household flood resilience in three flood-affected sub-districts in Tangerang City, Indonesia. The composite indicator method was applied to process data on economic, home environment, social capital, institutional, communication and information, and flood risk perception, using questionnaire data from 354 flood-affected households as respondents and in-depth interviews with local leaders. The results showed that the composite indicator method worked well for measuring the household flood resilience index (HFRI); in the Gembor sub-district, HFRI was 2.88; in Gebang Raya, it was 3.12; and in Periuk, it was 3.03. Analysis based on economic conditions, flood depth, period of residence, and flood risk perception also showed variations in HFRI, which could determine methods to increase household flood resilience. In conclusion, the composite indicator method is an adequate tool to measure flood resilience despite it being an abstract object. Furthermore, the local government can use the HFRI to develop planning efforts to increase household flood resilience based on influencing factors.
The effect of teak plantation growth on air temperature and oxygen level in green open spaces of the Research and Innovation Department of Perhutani Forestry Institute (PeFI)
Authors: Abdillah E , Muharyani N , Abror E M A
Published: June 2023

Urban land utilization for urban facilities construction continues to grow and impact the urban heat island making the city uncomfortable. Green open space (GOS) is a space within a city with its function in ecological, social, economic, and architectural functions. The purpose of the research was to determine the characteristics of GOS and the effect of teak plantation growth on air temperature and oxygen (O2) levels. The research was conducted from May to November 2021 using an observational design with a purposive sampling technique, considering the variations in measured variables: number of trees, daily climate, micro-climate difference, O2 level, and wind speed. The research analysis used a descriptive study approach relevant to the observed conditions. The teak arboretum and teak hedge orchard were the GOS at the Perhutani Forestry Institute (PeFI). Arboretum had a lower temperature and higher humidity than teak hedge orchard, making the arboretum in the cool-climate category with an ideal temperature of 26.9° C and dry humidity category. This means that the PeFi office was categorized as comfortable. The oxygen levels in PeFI were between 20.9 to 21.1%, meaning that the oxygen in the PeFI environment is highly available with the presence of GOS from the observed sites.
Uptake and translocation of lead and cadmium in wild-found plant species from Bekasi and Karawang, West Java, for phytoremediation
Authors: Davis L M M , Hidayati N , Firdaus A M , Talib C , Rini D S , Juhaeti T , Syarif F , Gunawan I
Published: June 2023

Environmental degradation due to lead (Pb) and cadmium (Cd) pollution has been increasing. One of the alternative cost-effective green technologies to clean up heavy metal contamination is phytoremediation. This research aims to determine the potential of wild-found plants that could be used as Pb and Cd bioaccumulators. Plant species in this study were collected from heavy metal-contaminated soil in Bekasi and Karawang, West Java. Five species, namely Saccharum spontaneum, Acorus calamus, Ipomoea fistulosa, Ludwigia hyssopifolia, and Eichhornia crassipes, were studied for Pb accumulation capacity. Furthermore, five plant species, namely Limnocharis flava, Colocasia esculenta, Ipomoea fistulosa, Commelina benghalensis, and Eichhornia crassipes, were studied for their Cd accumulation capacity. The experiment was done in a greenhouse for eight weeks. Pb and Cd concentration were analyzed using atomic absorption spectrometry (AAS) to determine the uptake and translocation of Pb or Cd. I. fistulosa accumulated the highest amount of Pb, with a growth rate of up to 27.07 g week−1, a bioconcentration factor (BCF) of 1.46, and a translocation factor (TF) of 0.87 upon 300 mg kg−1 Pb treatment. C. esculenta showed considerable Cd bioaccumulation, as indicated by a BCF of 0.95 and a TF of 0.65, accompanied by sustained relative biomass increase (124.9%) and the highest growth rate (36.96 g week−1) among tested plant species upon 75 mg kg−1 Cd treatment. With their capacities for bioaccumulating Pb and Cd, respectively, I. fistulosa and C. esculenta were identified as potential accumulator species for phytoremediation in heavy metal-contaminated sites such as former mining lands, landfills, and highly polluted agricultural lands.
Production of nanocellulose using controlled acid hydrolysis from large-scale production of micro-fibrillated cellulose derived from oil palm empty fruit bunches
Authors: Yurid F , Handayani A S , Maturbongs F D , Irawan Y , Sampora Y , Devy Y A , Septiyanti M , Ramdani D , Supriadi E , Amin K N M , Septevani A A
Published: June 2023

Nanocellulose is generally known as a versatile material, which is suitable for various applications due to its unique physicochemical properties, including light weight, ease of tunable surface functionalization, and excellent mechanical properties. This research aims to characterize and synthesize nanocellulose produced from acid hydrolysis of large-scaled micro-fibrillated cellulose (MFC) derived from oil palm empty fruit bunches by varying concentrations of H2SO4 from 20 to 35 v/v %. The obtained large-scaled MFC had a density of 1.01 kg/m3 and was dominantly composed of 71% cellulose. After acid hydrolysis of MFC, there were gradual changes in the colour of the obtained cellulose nanocrystals (CNC) dispersion from light white to a darker color with the increase of acid concentration, in which the over hydrolysis occurs at 35% of acid concentration. The use of 25-30% H2SO4 showed the optimum condition to avoid over-hydrolysis and resulted in bright white color of CNC dispersion with excellent stability at zeta potential value of -74.2±0.1 to -88.4±0.2 mV. It was supported by Fourier transform infrared (FTIR) due to the presence of negatively charged sulfonyl and hydroxyl groups upon CNC formation to offer excellent dispersion stability. Based on transmission electron microscope (TEM), rod-like shape CNC with a low aspect ratio of 11.8 at the dimension of 12.8 ± 6.7 nm in width and 151.9 ± 38.3 nm in length was successfully produced. Based on X-ray diffraction (XRD) analysis, the crystallinity of the sample was 76%.
Irradiation time dependent of the ZnO/GO composite formation on the photodegradation of Rhodamine B
Authors: Ezra  , Krismastuti F S H , Arutanti O , Aryana N , Hardiansyah A , Nugroho A
Published: June 2023

Rhodamine B (Rh B) is one of the dyes used in the dyeing of paints, acrylic, and fabrics as well as biological products. A high concentration of Rh B is highly toxic and dangerous to living organisms when directly discharged into water. Therefore, in this study, the degradation of Rh B in water by zinc oxide/graphene oxide (ZnO/GO) composite was investigated. The zinc oxide (ZnO) was recovered from zinc ash, waste from galvanization industries, by acid leaching process using hydrochloric acid (HCl), while the graphene oxide (GO) was synthesized by modified Hummers method. The nanocomposite of ZnO/GO was synthesized using microwave irradiation and characterized by means of Field Emission Scanning Electron Microscope (FE-SEM), X-Ray Diffraction (XRD), and Fourier Transform Infrared (FTIR). The effect of irradiation time during ZnO/GO nanocomposite formation on the photocatalysis activity of the ZnO/GO in degrading Rhodamine B under UV rays was studied. The irradiation time was varied for 6, 8, and 10 minutes. The characterization results confirm that ZnO, GO, and ZnO/GO have been successfully synthesized. The ZnO/GO nanocomposite was also responsive to UV rays and able to degrade Rh B, as one of the examples of water pollutants. The highest degradation of Rhodamine B is achieved by the ZnO/GO nanocomposite prepared at 10 minutes of irradiation. The results of this study demonstrate that microwave irradiation time affects the ability of the nanocomposite to degrade Rhodamine B.
Green Synthesis of Ag Nanoparticle-Decorated MgO Microspheres by Curcuma xantorrizha Extract and Its Potential Antimicrobial Activity
Authors: Purwajanti S , Nida V , Labanni A , Bahua H , Pongtuluran O B
Published: June 2023

Water pollution caused by bacteria is a significant global environmental issue that can pose serious risks to public health and ecological systems. Developing high-activity antibacterial agents is therefore crucial. This study describes the eco-friendly synthesis of Ag nanoparticle-decorated MgO microspheres, using C. xanthorrhiza extract as a reducing agent, without the use of stabilizers or surfactants. The Ag nanoparticles immobilized on the MgO microsphere support were analyzed using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The Ag/MgO microspheres exhibited antibacterial properties against both gram-positive and gram-negative bacteria. The findings suggest that Ag nanoparticle-decorated MgO microspheres could be a promising alternative for treating bacteria-contaminated wastewater, owing to their ease of preparation, low cost, environmentally friendly nature, and high antibacterial activity.
Protease production by soil bacteria for green technology: Screening and optimization
Authors: Ratnaningrum D , Kosasih W , Endah E S , Lathifa A K N , Diwan A M , Nida V , Saraswaty V , Risdian C
Published: June 2023

Protease is a type of enzyme that hydrolyzes proteins into peptides and amino acids. The demand for protease for green technology in some industries like detergent, food, and leather is increasing nowadays. Some soil bacteria, especially the Bacillus strains, are known to have the ability to produce protease. Compared to other sources like plant and animal origin, microbial protease has more advantages as it can be produced at an industrial scale, short cultivation time, and are easy to harvest. This research aimed to screen the proteolytic bacteria from the bulk soil samples collected under mango trees and to study the optimum condition for protease production using the response surface methodology (RSM). Three bacterial strains (SH2CR, SH3CR, and SC4CR) were isolated and shown to have proteolytic activity. Based on 16S rRNA gene analysis, the strain SH2CR was close to Priestia megaterium NBRC 15308T (96.97% similarity), while the strains SH3CR and SC4CR were related to Bacillus zanthoxyli strain 1433T (100% similarity). One of them, SH2CR, was further studied using a fermenter at a one-liter production scale with the medium containing skim milk at 30°C. The best condition for protease production by SH2CR was achieved at 48 h incubation time, 300 rpm of agitation, and 1.25% skim milk.
Determination of antioxidant activity, total phenolic, and total flavonoid contents from avocado seeds (Persea americana)
Authors: Kurniawan K , Rahmat A
Published: June 2023

In this study, the antioxidant activity, total phenolics, and total flavonoids of avocado seed extract were determined. The evaluation was observed towards methanol and ethyl acetate fractions by using the spectrophotometric method. The antioxidant activity of the avocado seed extract was determined by calculating the 50% of inhibition concentration of free radical scavenging activity towards DPPH radicals. The results showed that the IC50 of methanol and ethyl acetate fractions were 66 mg/mL and 63 mg/mL, respectively. The total phenolic content of the methanol fraction and the ethyl acetate fraction were almost similar at 48.6–48.7 mg/g dry weight of extract (gallic acid equivalent). Whereas the total flavonoid content of the methanol and ethyl acetate fractions was determined as 41.2–41.4 mg/g dry weight of the extract (quercetin equivalent). The phenolic and flavonoid compounds present in the fractions seemed to account for the antioxidant activity. Therefore, avocado seeds are a potential source of antioxidant compounds.
Preliminary study of microplastic in bottled drinking water
Authors: Syuhada  , Radini F A , Rusmana D , Liza C , Nur I M Z , Rifathin A
Published: June 2023

Microplastic is widely discussed and has become growing attention because of its negative impact on the environment and the well-being of living organisms. Some international studies have found microplastics in some foods and beverages, such as honey, beer, table salt, and drinking water. However, there are few accurate analytical techniques for identifying and analysing microplastics, especially in beverages and foods. This preliminary study investigates microplastics that might contaminate bottled drinking water, their physical properties, and their types of material. Five local brands of 120 ml bottled drinking water were used for this research, collected from a traditional market in South Tangerang. The samples were observed visually for microplastic’s presence, sizes, and shapes using a digital microscope. Furthermore, material identification using a Microscope - Fourier transform infra-red (μ-FTIR) was conducted to analyse the types of material present in the samples. The results show that all examined samples were contaminated, and the major pollutants were fibres with lengths between 0.042 and 3.668 mm. According to the material identification result using μ-FTIR, materials found in most samples are cellulose-based polymers, which are used widely for natural textiles (e.g., cotton) and synthetic fibres. In the five brands of the analysed bottled drinking water, neither the packaging material polypropylene nor the bottle caps made of polyethylene were detected. These findings indicate that the analysed bottled drinking water was not contaminated by microplastic, but by micro debris of natural cellulose-based polymers.
Distribution of Escherichia coli and coliform in groundwater at Leuwigajah and Pasirkoja Areas, West Java, Indonesia
Authors: Naily W , Sunardi S , Asdak C , Dida E N , Hendarmawan H
Published: June 2023

Escherichia coli and coliform are frequently detected in groundwater, and their abundant presence indicates that the groundwater has been contaminated. Several variables, including population density and well construction, contribute to the growth of E. coli and coliforms in groundwater. This is caused by domestic waste as a source of pollution being close to clean water sources (wells). This study aims to map the distribution of E. coli and coliform. The study was conducted at Pasirkoja and Leuwigajah in Greater Bandung, West Java, Indonesia. E. coli and coliform counts from 36 wells were carried out using the Petrifilm method with a 3MTM PetrifilmTM Rapid E. coli/Coliform Count Plate. The distribution of E. coli and coliform is represented by Quantum Geographic Information System (QGIS) software. The results showed that the number of E. coli and coliform mostly exceeded the quality standard. The distribution of E. coli and coliform is to the east of Leuwigajah and to the west of Pasirkoja.
Evaluation of ammonium issues in Indonesian groundwater: Potential sources and removal methods
Authors: Fahmi M A , Rohman A , Ahsan S A , Firmansyah F , Perdananugraha G M , Rusydi A F
Published: June 2023

Elevated concentration of ammonium (NH4
+) has been identified as one of the problems with groundwater because it indicates anthropogenic disturbance. In this study, we evaluated the NH4
+ presence in Indonesian groundwater and the land-use conditions possibly related to the issues. In addition, this research presents practical strategies for reducing NH4
+ concentrations in groundwater. The spatial distribution shows that high levels of NH4
+ are found in densely populated areas. Furthermore, land-uses analysis reveals that considerable concentrations of NH4
+ were found in several land-uses, including settlement, agricultural, fishpond, industrial, and garbage disposal, reaching 24.16, 7.73, 16.7, 7.42, and 84.9 mg/L, respectively. However, the statistical analysis shows that not all land-uses types significantly correlated with groundwater NH4
+ contents. Based on the p-value and confidence interval of 95%, NH4
+ concentrations are significantly correlated with settlements, brackishwater ponds, and garbage disposal. Similarly, industrial and agricultural land-uses have positive correlations with NH4
+ concentrations, although these correlations are insignificant. Finally, the promising methods for NH4
+ removal are the adsorption and ion exchange methods using zeolite or biochar, which could reduce NH4
+ levels by 90% and more. Furthermore, these methods do not require complicated application procedures.
Analysis of silica gel desiccant application in fuel storage tanks model to reduce palm oil-based biodiesel degradation
Authors: Azhad M F R , Fathallah A Z M
Published: June 2023

The need for a cleaner and more efficient engine arises as regulations on emissions become more stringent. besides increasing pollution and inefficiency concerns, manufacturing expenses are also on the upswing. As around 20% of all the energy used goes toward reducing friction, effective lubrication is a potential solution to the issues of efficiency, emissions, and engine wear. Several nanoparticles are being tried as potential performance-enhancing additions for engine oils. By sliding, polishing, rolling, and forming a third body, nanoparticles can improve liquid lubrication and lessen the contact between sliding surfaces. Because of its unusual characteristics, hexagonal boron nitride proven itself as a viable substitute for traditional inorganic solid lubricants. There has been a lot of study on how adding hBN nanoparticles to lubricating oil affects internal combustion engines. The impact of hBN as oil nano additions on engine fuel consumption, pollutants, and wear rate is the subject of this review study. Several studies show that hexagonal boron nitride, when added to engine oil, decreases the oil’s coefficient of friction (COF) and raises its thermal conductivity. From these improvements, lower fuel consumption, higher engine performance, lower exhaust gas emission, and prolonged moving parts wear rate are achieved for an internal combustion engine. This improvement will be beneficial to both operational and economic aspects.
Particulate Matter Concentration in Healthcare Facilities: The Influence of Natural Ventilation
Authors: Savanti Fisa , Wicaksono Dimas
Published: June 2023

Particulate Matter (PM) is an air pollutant that harms human health. Therefore, there is a particular concern about reducing indoor air pollutants. Natural ventilation supplies clean air into the room to reduce indoor pollutants and create good air quality. This research aims to determine the influence of natural ventilation on the particulate matter’s concentration in the room. First, the physical indoor air quality, including particulate matter, was measured using research instruments to obtain the primary data in healthcare facility buildings. Quantitative analysis is then carried out following the applicable recommended standards. The results indicate that natural ventilation can affect particulate matter concentration in the room and play an essential role in reducing it. Therefore, a building must consider good ventilation design to create better indoor air quality.
Characteristics and Antioxidant Activities of Three ‘Beras Kencur’ Effervescent Formulations
Authors: Astuti W , Hayati S , Dinata M A , Yonifasari C D , Wardania N R , Fitri Z A
Published: June 2023

This study aimed to evaluate the physical characteristics and antioxidant activities of beras kencur effervescent tablet formulations. Beras kencur was prepared in 7 different concentrations to assess the percent inhibition. The highest inhibition potency (76.2%) was found in beras kencur 10 mg/mL. This concentration was used to obtain the formulation of the effervescent tablet, which differed in definite proportions of citric acid (C6H8O7), tartaric acid (C4H6O6), and sodium bicarbonate (NaHCO3). When dispersed in water, the tablet produces a bubbling reaction by releasing CO2. The tablets were evaluated for pH, soluble time, total phenolic content (TPC), and antioxidant activity. These observations demonstrated that the higher proportion of NaHCO3 led to the higher solubility of the effervescent tablet. The antioxidant activity of formulations was evaluated using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and total phenolic content was determined using Folin-Ciocalteau. The outcomes suggested that the phenolics might become unstable at high acid conditions. In contrast, an increase in alkaline pH increased the ability of effervescent tablets to produce reactive oxygen species (ROS). The tablet with an equal proportion of acid and base showed the highest antioxidant activity (IC50 = 20.8), in line with the total phenolic content (5.772 mg GAE/mL).
Effect of Applying Strong Column Weak Beam to the Laboratory’s Artificial Lighting System
Authors: Hangga Arimaz , Nisa Alim Muanifatin , Triantino Septiandi Budi , Khoirunnisa Fitriana , Wulan Anissa Purnama , Khoerunnisa Anissa
Published: June 2023

Lighting is one of the crucial experiment factors in the laboratory. Laboratory’s lighting system that follows the Indonesian National Standard (SNI) can improve visual comfort during experiments. This research aims to determine the effect of strong column weak beam (SCWB) on illuminance in the laboratory according to SNI 6197:2011. The results were expected to provide recommendations for the implementation of SCWB in the laboratory so that the laboratory lighting system was more optimal. Digital Electronics Laboratory, E8 Building, Universitas Negeri Semarang had dimensions of 12m x 7m x 4m. The measurement of illuminance used general measurement and task measurements according to SNI 7062-2019. Illuminance data retrieval was carried out in two ways, namely observation and simulation. Measurement of laboratory’s illuminance by observation has been carried out for 10 days with repetition 10 times. The simulation of illuminance measurement used Dialux 10. Based on the results of observations and simulations, it can be seen that the Digital Electronics Laboratory did not follow SNI 6197:2011 with an illuminance of 31.3 – 137 lux. The simulation used the modifying lamp layout and applying TL LED (Philips Master LEDTube HO) so that the illuminance distribution of the Digital Electronics Laboratory followed SNI 6197: 2011 of 500 – 769 lux. The simulation results of the SCWB dimension variation showed that the recommended thickness of the SCWB was between 10 cm – 30 cm to obtain a more optimal illuminance.
Passenger’s Level of Satisfaction with and Loyalty to Trans Semarang Bus Services
Authors: Haryadi Bambang , Damayanti Ervina , Alam Monacella Lieta , Narendra Alfa , Purnomo Andi
Published: June 2023

The rapid development of motorization in the city of Semarang caused an increase in congestion. This prompted the City of Semarang Government to provide adequate, safe and comfortable public transportation for the community. The public transportation service introduced in 2009 was a rapid transit system called the Trans Semarang Bus Rapid Transit (BRT). This study aims to measure the passenger’s level of satisfaction with and loyalty to Trans Semarang bus services. We measured satisfaction using the Customer Satisfaction Index (CSI) method. The satisfaction index is based on five dimensions of service quality, namely: physical, reliability, responsiveness, assurance, and empathy. The results showed the value of the CSI of 69.17 percent. This means that overall passenger satisfaction with the Trans Semarang bus service is still low. The level of passenger loyalty to Trans Semarang buses was measured by their intention to use the service in a sustainable manner is 78 percent. This means that if there is another alternative, the probability of leaving the Trans Semarang bus is 22 percent. The quality of Trans Semarang bus services still needs to be improved to increase passenger satisfaction with and loyalty to the bus services.