Table of contents

Proceeding of The 5^th International Symposium on Green Technology for Value Chains

(GreenVC) 2021

October 11 - 12, 2021

Bandung, West Java

Indonesia.

Organized by:

Research Unit for Clean Technology

National Research and Innovation Agency (BRIN)

Preface

The fifth International Symposium on Green Technology for Value Chains (GreenVC) 2021 was held on October 11-12, 2021 virtually in Bandung, West Java, Indonesia. The fundamental goals of this symposium are to exchange ideas and information, encourage technology in development, and strengthen networking and collaboration among all attendees. The symposium was organized by the Research Unit for Clean Technology, National Research and Innovation Agency (BRIN).

The proceedings of GreenVC 2021 presents the original and unpublished results in all areas of interest. Totally 31 papers have been selected to be published based on the originality and suitability with the symposium topics. Waste treatment and management, green materials and processes, environmental monitoring and assessment, life cycle and socio-technology of green production, environmental nanotechnology, and Covid-19 waste treatment are among the subjects covered in this symposium.

We would like to express our sincere gratitude to our Advisory Board, Scientific Reviewer and Editorial Board for their positive contribution to keeping the quality of the articles presented in this proceeding. We also would like to appreciate all participants attending this symposium as well as to the Organizing Committee, who made the symposium successful.

Dian Andriani, M.Eng.

Editor in Chief

List of titles Venue and Date, Organized by:, Committee, Editorial Board, List of Participants, Sponsorship, Conferences Documentation, Table of Contents are available in this Pdf.

All papers published in this volume have been reviewed through processes administered by the Editors. Reviews were conducted by expert referees to the b rofessional and scientific standards expected of a proceedings journal published y IOP Publishing.

• Type of peer review: Double Anonymous

• Conference submission management system: Morressier

• Number of submissions received: 44

• Number of submissions sent for review: 44

• Number of submissions accepted: 31

• Acceptance Rate (Submissions Accepted / Submissions Received × 100): 70.45

• Average number of reviews per paper: 2

• Total number of reviewers involved: 38

• Contact person for queries: Name: Dewi Nilawati

Email: greenvc@mail.lipi.go.id

Affiliation: National Research and Innovation Agency

WHO declared a novel coronavirus in humans as Coronavirus Disease 2019 (COVID-19) on February 2020, and Indonesia as well as Bandung City have been suffering from COVID-19 since the first case in March, 2020. Currently, the outbreak of COVID-19 has occurred for more than a year. The COVID-19 pandemic had a severe impact on the environment, like the enhancement of household solid waste as a result of work and school from home policies to decrease the rates of COVID-19 cases. This study aimed to predict the amount of household solid waste generation and analyze the waste management during COVID-19 in Bandung City using a system dynamics model. Data for model input was obtained from questionnaire to 200 respondents from Bandung spread across the sub-districts. The results revealed that the household solid waste generation was increased by 1.3 to 3.8% compared to the year before the COVID-19 pandemic. The composition of household solid waste was dominated by food and plastic waste, which have increased to 76.43% and 25.81%, respectively. The system dynamics model has predicted the household waste generation from three management scenarios for 30 years of model simulation. Scenario I: the household solid waste was totally managed by a local sanitary agency (existing condition); Scenario II: each household manage their waste by recycling; and Scenario III: the utilization of a local waste bank to manage the waste. The scenario III showed the most effective waste management to reduce the amount of household solid waste generation up to 24% by using waste bank. This scenario can be applied for more prolonged landfill operations up to 17 years.

There are indications that Artisanal Small-Scale Gold Mining (ASGM) in Banyumas Regency is still using mercury for gold extraction. Mercury is a persistent and toxic compound for numerous organisms and human health. This research aims to describe the gold processing using mercury in Banyumas Regency based on an investigation in the location of the mining site and gold processing site. Further, monitoring the mercury level in several places was also conducted, such as water drain at gold mining area in Ajibarang District, Tajum River water, mercury waste reservoir and well water in the gold processing area, and water from processor lavatory. Our investigation showed that the extraction process takes place in a gold processor located in a populated area. Gold mercury amalgam is separated from the remaining mercury during this process, and the mercury waste is collected in a mercury waste reservoir. Usage of mercury must be a concern for gold processors and the local government because the Indonesian government is targeting that by 2025, ASGM will no longer use mercury-based on the National Action Plan for Reduction and Abolishment of Mercury Use. Furthermore, mercury levels from mercury waste reservoirs exceeded the quality standard according to Government Regulation No. 82 of 2001, and the Regulation of the Minister of Health No. 32 of 2017, reached 673 ppb. It was because the sampling location was directly linked to the main activity of gold processing. However, attention and effort are required to treat mercury waste in reservoirs not to pollute groundwater in the future. Furthermore, several strategic programs are necessary to implement good traditional gold mining under government monitoring.

Economic agglomeration is the concentration of many firms and industries in close proximity that is considered effective in urging growth across developing countries. Despite the advantages, limited studies are examining negative externalities as a result of economic agglomeration towards the environment, including on water quality. Indonesia as an island country has experienced notable economic growth in the last 20 years, but at the same time currently contains some of the worst polluted rivers in the world. Using the linear regression method, this study measured the effect of economic agglomeration on water quality index (WQI) across 34 provinces in Indonesia between 2013-2018 using random effect on panel data sourced from The Ministry of Environment and Forestry and Statistics Indonesia. The results reveal that economic agglomeration had a significant and negative effect on water quality by 0.2% on the index. The relationship was consistent even when controlled for other variables like population, sanitation access, foreign direct investment (FDI), the proportion of secondary industries, and gross regional domestic product (GRDP). Furthermore, there was also a significant effect of FDI on WQI. These results call for a sound regulatory framework to protect the water quality from economic agglomeration in order to avoid environmental degradation.

Liquid waste from spent-battery recycling contains heavy metals that are harmful to the environment. This study aimed to eliminate the dissolved cobalt, cadmium, nickel, manganese, mercury, and arsenic in the liquid waste. A combination of the chelation method and electrocoagulation method using monopole parallel circuit with aluminum electrodes was tested. The influence of specific chelating agents (citric acid and chitosan) concentration and contact time on the removal efficiency were investigated. Electrical energy consumption and the specific number of dissolved electrodes were calculated from the optimum condition. The method with the chelation followed by electrocoagulation gave the best result than the other way around. The best removal efficiency for all elements was above 99.5% using chitosan at a concentration of 6 g/L, a current density of 25 A/m², and a contact time of 30 minutes. Energy consumption and dissolved electrodes were 0.0429 kWh/m³ and 0.4074 g, respectively. The output of this method meets the Indonesian water quality standard and can be a novel wastewater treatment technology.

Air pollution is directly proportional to the rate of economic growth. With the growing economic life, more people will use high-tech materials, which can cause air pollution. The main problem of this pollution is decreasing air quality. This decrease in air quality is caused by many things, including excessive environmental exploitations, industrial activity, energy use, and vehicles exhaust emissions, all of which trigger pollution problems. Bandung Regency is surrounded by many industries, i.e., textile, garment, metal, printing, metal, food, furniture, and plastic. Thus, monitoring air pollution is imperative. The air parameters measured were Carbon monoxide and Nitrogen dioxide. The measurement duration is every 14 days, from June to July 2021. The sample location is divided into four regions, Margahayu, Kopo Katapang, Baleendah, and Dayeuh Kolot. The method used was the MCU 6814 sensor which has been calibrated by IQAir. Carbon monoxide measurements were taken every 8 hours, while nitrogen dioxide was measured every hour of the day. The average measurement for the four areas in the morning and evening was relatively good, 3-5 g/m³ for CO in the morning and 10-14 g/m³ at peak activity during the day. These results indicated the unhealthy air category.

The water's acidity level will impact the water's suitability for fish survival. Fish waste and food residue, on the other hand, can reduce the acidity of the water and produce toxic ammonia, which is damaging to fish. Biofloc technology (BFT) can transform toxic ammonia into floc protein, which can be used as an alternative diet. However, the acidity of the pond water must be monitored to ensure that biofloc techniques are implemented successfully. Tilapia is a popular fish among Indonesians, although it is difficult to farm using biofloc technology, which is important for public food preservation. This research aims to build technology for monitoring and validating waters acidity levels in tilapia biofloc ponds. Observing the quality of pool water acidity is carried out automatically through a microcontroller. The pH powder calibrator provides accurate validation of water acidity sensor measurements. The monitoring results of pH by around 7.38±0.15 showed that the average level of acidity of the biofloc water was still following the pH tolerance of Tilapia. This proposed monitoring method is highly beneficial for supporting national food security through BFT fisheries, particularly to avoid the mass mortality of Tilapia because of poor water acidity conditions.

The widespread use of nonylphenol (NP) in various industries, in turn, give a negative impact on the environment and living organisms since it has had several harmful effects on the aquatic organism. Hence, its level of contamination should be regularly monitored. However, due to its low concentration level, the determination of NP is challenging. Solid-phase extraction (SPE) could be utilised to detect a low NP dose in water. One of the most important factors for SPE extraction is selecting the proper adsorbent, and molecular-imprinted polymers (MIP) are considered the appropriate adsorbent in SPE extraction. This study aimed to synthesise and characterise the MIP for NP by precipitation polymerisation. Methacrylic acid (MAA), ethylene glycol dimethacrylate (EGDMA), benzoyl peroxide, acetonitrile, and NP were used as a functional monomer, a crosslinker, an initiator, a porogenic solvent, and a template molecule, respectively. The MIP was characterised using FTIR, SEM, and TGA. The results showed that the precipitation polymerisation method produced larger adsorbent particles and the polymerisation process was faster compared to bulk polymerisation. Based on the large particle size of the adsorbent and the fast polymerisation process, synthesis using the precipitation polymerisation method can be used for rapid routine analysis.

Indonesian Presidential Regulation No. 21 of 2019 to reduce and eliminate mercury has increased the intensity of monitoring activities of mercury levels in various matrices, and it should be supported by the high quality of analytical data. The analytical method's performance characteristics, i.e., the limit of detection, linear range, precision, trueness, have been successfully carried out, and the method was shown to be fit for purpose. The limit detection, LoD and LoQ, were found to be 0.003 and 0.010 mg/kg, respectively, adequate to reach the applicable regulatory limit. The examined linearity range up to100 µg/L has been found suitable for its application since the regulatory limit for mercury in sediment is relatively higher (2 mg/kg). Precision and trueness aspects of the method were shown to have satisfying performance, with CV of 3.28% and recovery of 81.5%. All possible uncertainty sources have been identified in this study. Since no reference material was available, the uncertainty of bias was evaluated through the recovery of the spiked sample. Evaluation of compliance of measurement results with the regulatory limit was performed for each corresponding uncertainty. Out of four, two results were far above the limit, and the other was clearly below the limit.

Carbon nanodots (CNDs) are considered as potential materials for photothermal applications and can be used as solar absorbers to enhance the absorption and conversion efficiency of solar energy to heat. To meet the criteria as solar absorbers, CNDs were synthesized via microwave heating and dried by two different drying processes, namely freeze drying and oven drying, obtaining CNDs powder with the labeled of CND-FD and CND-OD, respectively. The effect of these two drying methods on the optical and photothermal properties of CNDs was investigated. It was observed that soft and light powders were obtained from freeze drying, while oven drying resulted in shiny and agglomerate particles. Oven drying did not alter the absorption profile of CNDs, but freeze-drying resulted in broader and slightly red-shift absorption compared with that of CNDs colloid before drying. Photoluminescence intensity of CND-FD was only half of that of CND-OD. FTIR analysis revealed that CND-FD contained fewer hydroxyl and hydrophilic amine groups, leading to less hygroscopic nature of CND-FD than CND-OD. Because of its better absorption capability, the presence of CND-FD in water significantly increased the water evaporation rate and evaporation efficiency up to 2.2 kg/m².h and 84%, respectively, three times higher than that of water without CNDs. With a similar photothermal testing condition, CND-OD resulted in a evaporation rate of only 0.9 kg/m².h and evaporation efficiency of 36%. It can be noticed that freeze drying is more suitable to dry CNDs powder over oven drying to obtain excellent optical and photothermal properties of CNDs.

The widespread application of titanium dioxide nanoparticles (TiO₂ NPs) in consumer products impact the environment, especially the aquatic ecosystem. The more nano TiO₂ products used due to human needs, the more negative impact. Herein, we report a preliminary toxicity study of two types of TiO₂ NPs (rutile and anatase) on bacterial from sediment of Citarum River through the cell viability determination. A total of 10 bacteria has been successfully isolated and identified through 16S rRNA gene sequencing. For toxicity testing, the isolated bacteria were then exposed to 100 mg/L of TiO₂ NPs suspension at 30 °C for 24 hours under natural light conditions. The results show that isolates bacterial in the samples were identified as Proteobacteria phylum belonging to the Actinobacteria, Betaproteobacteria, and Gammaproteobacteria classes. TiO₂ NPs exhibited the highest growth inhibition to Citrobacter freundi (71.94% for rutile phase) and Enterobacter asburiae (79.24% for anatase phase). Rutile and anatase showed different effects in cell growth for the Actinobacteria (closely associated with Streptomyces sp.). Anatase induces cell growth (112.39%, cell viability), while the rutile phase is the other way around (74.35%, cell viability).

A rare-earth element (REE) is one of the minerals with many resources in Indonesia and lanthanum is one of REE. Lanthanum is widely used as a material for x-ray screens, glass lenses, optical fiber, capacitor batteries, and ceramics. Electrodeposition is a metal deposition process. The advantages of electrodeposition are easy and inexpensive. The method is simple since it can be done at room temperature, and it is inexpensive because it only requires basic equipment. However, there is a drawback to conventional electrodeposition: the roughness of the resultant layer (non-uniform crystal growth). Magnetoelectrodeposition (MED) is a solution for solving this problem. We employed the MED method in this study, which is the electrodeposition procedure under the influence of a magnetic field, and there has been no previous research on lanthanum MED. The electrode area, magnetic field strength, electroactive concentration, diffusion coefficient, and kinematic electrolyte viscosity were variables used in this study. The lanthanum MED in this study used 98% lanthanum (III) chloride heptahydrate (LaCl₃.7H₂O) for analysis from Merck, which was leached at a particular concentration of sulfuric acid (H₂SO₄), using platinum electrodes in three electrochemical cells, and varying the magnetic field strength from 0 to 0.08 Tesla. The results showed that the stronger the magnetic field, the greater the limiting current for lanthanum electrodeposition. The effect of electrode area and electroactive concentration also gives rise to the limiting current. Meanwhile, the viscosity of the solution and the diffusion coefficient will cause a reduction in limiting the current value.

Chitosan is a natural product of chitin deacetylation, and low molecular weight chitosan (oligo chitosan) can be produced in the liquid phase by irradiation technique. Due to the long molecular chain and high molecular weight, the application of chitosan is limited. This study aimed to prepare oligo chitosan by irradiation technique in liquid phase at a capacity of 1000 L. Irradiation was carried out with gamma rays from a C0-60 source. The first stage of this study was to standardize chitosan properties (viscosity and molecular weight) to be pumped and flowed to the irradiation tank. In large-scale liquid phase chitosan irradiation, the chitosan solids must be standardized to lower the viscosity and enable flow by pumping or gravity. The experimental results show that for the chitosan liquid to flow from the mixing tank to the irradiation tank, the initial chitosan must have a molecular weight of 12-15 kDa to obtain a viscosity of 100-200 cps. The irradiation method was very effective in reducing molecular weight and viscosity. Irradiated chitosan had a low decrease in thermal properties and a molecular weight of 9.2 kDa. Functional group analysis shows that there were still functional groups of chitosan in irradiated chitosan.

Indonesia is a maritime country that is rich in seaweed. However, seaweed fermentation into lactic acid is not yet usually. Seaweed fermentation has outstanding potential because it has the most abundant polysaccharides compared to other sources. This research aims to synthesize lactic acid by fermentation using a single culture of Lactobacillus plantarum (L. plantarum) and two substrates, namely seaweed flour and refined salt Kappa-Carrageenan (RKC). Lactic acid was analyzed by fourier-transform infrared (FT-IR) spectroscopy and its concentration was determined by gas chromatography-mass spectrometry (GC-MS). The proximate analysis showed that crude Fiber and starch levels in seaweed are 25.37% and 14.66% (w/w) and also in RKC are 16.45% and 1.07% (w/w), respectively. The highest reducing sugar was attained at H₂SO₄ 2% (w/w), which were 51,184 mg/L in RKC and 24,824 mg/L in seaweed flour. Based on FT-IR data, lactic acid characteristic signals were found at broadband approximately 3000 - 3500 cm⁻¹, which indicated the presence of OH band, a band at 1656 cm⁻¹ revealed C=O stretching of carbonyl groups, and a band at 1118 cm⁻¹ for C-O stretching of alcohol. Based on GC-MS data, the highest lactic acid production was 42,267 mg/L in RKC and 37,130 mg/L in seaweed flour. In this study, we can conclude that the efficiency of hydrolysis and fermentation of RKC was better than seaweed flour. However, the substrate concentration for optimum lactic acid production was unknown, so a more in-depth study was needed.

The sorghum bagasse (SB) particle was used as a filler for the manufacture of rigid polyurethane foam composites (RPUFC). The purpose of this research was to investigate the effect of SB particle content and variation of composite density on the physical, mechanical, and morphological properties of RPUFC. The RPUFC was created with five different volume fractions of SB particles (0, 2.5, 5, 7.5, and 10 wt.%) and three different composite densities (40, 50, and 60 kg/m³). The SB particles, polyols, and isocyanate were mixed, poured, and formed in a closed mould. The physical and mechanical properties of the RPUFC were determined according to standard methods. The physical properties (moisture content, water absorption, thickness swelling) were increased with increasing SB particle content in the RPUFC. Meanwhile, the mechanical properties (flexural and compressive strengths) tended to decrease with increasing SB particles but increase with increasing density of RPUFC. The best RPUFC, which had properties equivalent to RPUFC without the addition of particles, was produced with the addition of 2.5% particles at densities of 50 and 60 kg/m³.

Gerrit Augustinus Siwabessy (GAS) multipurpose reactor has been utilized for various purposes, such as radioisotopes production, material testing, and trace metals analysis. The operation of this reactor generated high-level radioactive waste in the form of spent nuclear fuels. For safe and secure means of the storage of the spent fuels, the data of radionuclides inventory in the spent fuels is critical. The purpose of this study is to determine the inventory of spent fuel generated from the research reactor operated at a power level of 15 MW. This power level was selected because the reactor has been operated at this power level value. The calculation was carried out using Origen 2.1. The calculation results show that a spent fuel freshly discharged from the reactor contained radionuclides with a total activity of 52083.15 Ci, which decreased dramatically within five years. The decay heat generated by the spent fuel was 200.726 W which decreased as the storage time increased. The spent fuel generated neutrons emission of 8.86 × 10³ n/s and photon emissions of 5.356 × 10¹¹ p/s. Similar to the total activity, these neutron and photon emissions decreased dramatically within five years after being discharged from the reactor. These calculation results are necessary for further use in assessing the management of the spent fuel.

Sodium bicarbonate (NaHCO₃), known as baking soda, can be used as a baking powder, disinfectant, fire extinguisher, mild disinfectant, antiseptic to help prevent infections, acid neutralizer, cleaning agent, odor control, and antacid to treat acid indigestion and heartburn in medical and health use. Sodium bicarbonate is commonly produced using the Solvay process that uses brine (seawater), ammonia (NH₃) gas, and carbon dioxide. To reduce the costs of sodium bicarbonate production, this study used ammonium hydroxide (NH₄OH) solution, a byproduct of sodium cyclamate factory, to replace the NH₃ gas. Hence, this modified Solvay process is more environmentally friendly. Ammonium hydroxide is a weak base suitable to produce food-grade sodium bicarbonate because it does not contain heavy metal impurities. The following parameters were studied and optimized namely reaction time, NaCl concentration, and CO₂ flow rate. The appearance of the microstructure, particle size, percentage of elements, and phase composition of the material was examined X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy with Energy Dispersive X-Ray Spectroscopy (FESEM-EDX).

Synthesis and characterization of magnetite-nanoparticles (MNc) were successfully carried out by coprecipitation of both Fe³⁺ and Fe²⁺ ions for the potential use in the environmental application. The obtained MNc was characterized by VSM (Vibrating Sample Magnetometer), X-Ray Diffraction, and Scanning Electron Microscopy, and then it was compared to the commercially available magnetite (MNo). Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) is also carried out to investigate the adsorption efficiency of the obtained MNc towards various types of heavy metals. The resulting MNc was superparamagnetic, as noted by a zero coercivity value. The pure MNc synthesized in this study showed X-Ray Diffraction patterns of several peaks in the 2θ range of 5° to 70°, which were the main characteristic peaks of the crystal plane indicating the formation of magnetite nanoparticles. These results show a higher purity of magnetite than that of MNo. Based on the Scherrer method, the main crystal size of magnetite nanoparticles was around 9.859958 nm. Further, the SEM results showed that the morphology of Fe₃O₄ was spherical nanoparticles, but they tended to agglomerate into large particles with a size of about 1.5 ± 0.9 μm. The ICP analysis showed that the obtained MNc could adsorb several types of heavy metal ions, such as Cd, As, Cr, Se, Ti, Ni, Pb, Be with a percentage of efficiency in the range of 3-64%. As expected, the MNc also afforded better metal ions adsorption performances compared to commercially available magnetite (MNo).

The gate-to-gate system boundary was employed to determine the greenness of sample preparation methods for simultaneous pyrethroids analysis using life cycle assessment (LCA). The LCA of an established QuEChERS method was assessed and compared to the proposed modified QuEChERS method. A comparative LCA was carried out with a functional unit defined as the amount of pyrethroid recovered (80-110%) from a 5 g soil. The life cycle inventory and life cycle impact assessment (LCIA) were performed on Open LCA 1.10.3 software. The inventory analysis shows that the amount of equipment, material, and energy input were greater in the proposed modified QuEChERS method than the established QuEChERS method, except for chemicals used. The life cycle assessment impact shows that among the nine impact parameters generated, the established QuEChERS method was more environmentally benign than the proposed modified QuEChERS method. However, in term of carcinogenic toxicity impact on humans, the proposed modified QuEChERS method outperformed the established QuEChERS method. This study confirmed the contribution of life cycle assessment to assess the environmental impact for the analytical procedure.

Polypropylene (PP) is one of the most frequently used polyolefins, with applications in a wide range of industries. PP is the most often used plastic in Indonesia. However, because to its resistance to microbial breakdown, it persists in the environment, causing environmental issues. In this study, Lysinibacillus macroides isolated from the coastal area of Muara Angke in Jakarta was screened for the ability to degrade polypropylene film and beads using Bushnell Hass media. After 50 days of incubation, biodegradation of polypropylene film and beads were examined. Both inoculated PP beads and film were examined by the percentage of weight loss, SEM analysis, and TG/DTA analysis. FTIR analysis and XRD analysis were also used to evaluate PP film degradation. Lysinibacillus macroides showed 1.33% PP film degradation and 2.93% PP beads degradation by weight loss in 50 days, respectively. Compared with the PP film, the degradation efficiency of the PP beads was significantly improved. This study can be used to assess the efficiency of different types of plastics in terms of bacterial decomposition. It also paves the way for the development of a more efficient screening approach for determining the most effective microbe for various types of plastic biodegradation. Despite the many optimizations that are required, the isolated strain demonstrated positive potential for polypropylene biodegradation of both films and beads.

On the main aquatic system, the nutrients even essential for ecological balance it could contribute the adverse effect in excessive quantities. These nutrients are related to the activities along the river. To prevent further effect, the biological treatment has been developed to control the river quality. Biofiltration system as low maintenance cost technology could be conducted to handle the excessive nutrient. This study would discuss and construct the assessment framework of biofilter application on various types of advance packing material and system from ecological aspect. The systematic literature review was conducted to understand which predominant nutrient would affect the river quality, how the parameters interact in the aquatic system, and the effect of material on biofilter system. This framework would strengthen the understanding of biofilter application on the river water.

Observations were carried out on the vetiver plant (Chrysopogon zizanioides L. Roberty) that functioned as a biofilter in a modified floating net cage (KJA) system in the Cirata Reservoir, West Java, Indonesia. The plant was designed to filter the residual organics and nutrients from the fish feed residue. In this study, the vetiver was planted in 30 L containers and fed continuously with water containing fish feed residue. Observations were made once a week for 75 days, focusing on the physical growth of the shoots or tillers, roots and leaves of the plants. Parameters that affected the environmental conditions were also analysed, namely pH, temperature, turbidity, dissolved oxygen, chemical oxygen demand (COD) and nitrate. The results show that the maximum root length was 110 cm and the maximum leaf length was 140 cm. The water pH was in the neutral range of 6–8 and the temperature was stable in the range of 28-30 °C. Vetiver could decrease the COD concentration from 24–28 mg.L⁻¹ to 14–18 mg.L⁻¹. This shows that the vetiver could utilize nutrients from organic waste derived from fish feed residue and act as a biofilter in the KJA system.

The electroplating industry is one of the industries producing various kinds of pollutant waste. One of the pollutants is Copper (Cu). It can cause environmental problems such as soil pollution that endanger microorganisms and other living beings and shift its ecological balance. Phytoremediation is a way to improve polluted land by using plants. This study aimed to investigate the reduction of Cu after the treatment of vetiver (Chrysopogon zizanioides (L.) Roberty). Plants were grown on contaminated soil for 28 days (absorption condition), then transferred to the soil without contamination and allowed to live for 28 days (elimination condition). In this study, the concentration of Cu heavy metal was analyzed in plants using Atomic Absorption Spectrophotometer (AAS). Phytoremediation potential was evaluated through absorption rate, elimination rate, along with Bioconcentration Factor (BCF), Biological Absorption Coefficient (BAC), and Translocation Factor (TF). The results showed that C. zizanioides could absorb Cu with the highest absorption rate of 1.45 mg.kg⁻¹.d⁻¹ and the highest elimination rate of 0.36 mg.kg⁻¹.d⁻¹. The absorption rate tends to be higher than the elimination rate. In this case, C. zizanioides can be used as an alternative for phytoremediation of Cu contaminated soil in the lightly to heavily polluted category.

Textile effluent could endanger human health and the water environment, but it is very challenging to be treated due to its complex composition. Biological methods for textile wastewater treatment by using fungi has been extensively studied in a lab-scale yet the investigation on a larger scale is still limited. In this study, a preliminary investigation of immobilized Trametes hirsuta D7 in light expanded clay aggregate (myco-LECA) application was conducted to treat the real textile wastewater in a rotating drum biological contactor. The undiluted wastewater without any addition of carbon and nutrients was used in the experiment and treated for 72 hours in the batch-mode bioreactor. The results revealed the maximum decolorization of 74.62% along with the highest laccase activity observed at 107 UL⁻¹. Moreover, the pH was successfully reduced from 12.94 to 8.57 while the chemical oxygen demand still fluctuated. In terms of nutrients, 57.4% of phosphorus (PO₄-P) removal was achieved but no observation of the nitrification process. Based on the toxicity assay using Artemia salina larvae, the treatment could reduce the toxicity level and performed a total chromium removal up to 36.5%. These findings showed the promising abilities of myco-LECA for textile wastewater treatment prior to the full-scale application.

Palm oil mill effluent (POME) is one of the major issues in the palm oil industry. POME contains high organic materials that can be used as a growth medium for microalgae. This study investigated the performance of immobilized Nannochloropsis oculata in a down-flow hanging sponge (DHS) reactor for the treatment of POME. The reactor was inoculated with N. oculata and continuously supplied with POME that operated in 2 phases for 42 days. The reactor shows excellent performance for the pollutants removal efficiency. In Phase 1, the reactor has successfully removed COD, colour, ammoniacal nitrogen (NH₃-N), and phosphate at the highest removal efficiency of 63%, 89%, 75%, and 65%, respectively. In Phase 2, when the influent flow rate was reduced, the removal efficiencies of COD, NH3-N, and phosphate enhanced to 73%, 80%, and 83%, respectively. Meanwhile, the colour removal efficiency was slightly decreased to 80%. These results revealed that N. oculata cultivated in a DHS reactor was able to remove pollutants in POME. The organic contents in POME were utilized as nutrients to support microalgae growth through photosynthesis. In addition, this method could be an alternative method to cultivate microalgae for biofuel production.

The study of Fe, Ca, and Mg removal from wastewater using the electrocoagulation method in the Center for Accelerator Research and Technology (CART) has been carried out. Electrocoagulation is one of the effective wastewater treatment methods, especially for metal removal. The main purpose of this study was to evaluate the effectiveness of the electrocoagulation method in CART wastewater treatment, especially Fe, Ca, and Mg removal, before being released into the environment. The electrocoagulation reactor operates continuously using aluminium electrodes. Several parameters were used to obtain the optimal condition for Fe, Ca, and Mg removal: operational time, flow rate, and electrode distance. The result showed that the optimum condition is on the operational flow rate 1 mL/s, the processing time 2 minutes, and the distance between electrodes is 1 cm. The optimum efficiency for Mg, Fe, and Ca removal was 96.0%, 95.2%, and 79.15%, respectively; meanwhile, Total Suspended Solid (TSS) decreased by 87.5%. In addition, the kinetic model in this study was carried out by determining the reaction rate constant (k) as a function of time for three variations of flow rate. The k value for Ca and Fe removal followed the second-order kinetic model, while the Mg removal fitted the first-order kinetic model.

Antibiotic contamination is an ever more dire problem due to the massive usage of antibiotics, removal complexity, and detrimental impacts on the environment. The consumption of antibiotic contaminated food and water bring negative impact on biota and human health, and further promote the development and dissemination of antibiotic resistance. Therefore, the establishment of an effective antibiotic waste treatment platform is important. Presently, there are few reviews about antibiotic bioremediation using microorganisms. The present review highlights the alternative approach of antibiotic bioremediation using microorganisms, factors affecting the degradation processes, and the challenges in the bioremediation using microbes. This review utilises a web-based purposive search for literature published from 2010 to 2021. Studies reported that either bacteria, yeast, or fungus have the ability to degrade antibiotic compounds. The biodegradation can use pure isolate or microbe consortia. The degradation efficiencies were affected by the species or strain of microbe, inoculum size, antibiotic structure, media composition, and the fermentation condition. The limitation and future perspective of the antibiotic bioremediation using microorganisms also will be discussed. We conclude that bioremediation is a prospective technique to overcome antibiotic pollution.

Indigosol blue (IB) is a synthetic dye with good durability and is usually used in the batik industry. However, due to its toxicity, carcinogenicity, and mutagenicity, this compound negatively impacts the environment and humans. Herein, the local Basidiomycota, Lepiota sp., isolated from the Baturraden Botanical Garden on Mount Slamet, Central Java, Indonesia, was utilized to decolorize the IB. It is considered an alternative method because it can degrade dyes efficiently and environmentally friendly through adsorption and enzymatic mechanisms. The purpose of this study is to investigate the capability of Lepiota sp. to decolorize IB batik industry effluent with different incubation periods and glucose concentrations. In addition, the optimum condition for the biological treatment was also determined. The potential of Lepiota sp. was by calculating the level of decolorization of the IB batik industry effluent. It was grown in a liquid medium and then exposed to IB batik industry effluent. Decolorization was studied using fungal mycelium that had been incubated for 7 × 24 hours. The experimental results were then expressed as the percentage decolorization and the total dry weight of the mycelium. The Lepiota sp. exhibits its potential to decolorize IB with % degradation in the range of 45.29% to 85.78%. The highest percentage was shown at 72 hours incubation period and a 1% glucose concentration.

Hungary is a country in Central Europe with the population of 10 million people. In the second half of the last century, it belonged to the so-called communist block with the typically poor municipal waste and wastewater treatments. After the change of the political regime in 1989 and joining the European Union in 2004, there has been a huge development in these areas. The management of municipal solid waste now-a-days implements effective, countrywide separative collection, sorting plants for separately collected packaging materials, composting and biogas plants for biowaste, as well as facilities on the mechanical-biological treatment of residual fraction. As a result, the recycling rate of materials and energy is rather high. The municipal wastewater treatment system has been developing since, the wastewater sewerage system covers now over 80% of the population. The wastewater treatment in all treatment plants incorporates three stages: mechanical, biological and advanced chemical one. Nevertheless, there are newer and newer targets and challenges. One of the most important tasks is to develop a sustainable sewage sludge treatment system aiming at the converting of this by-product into agricultural or energetic values. In Indonesia with 270 million people, according to the Indonesian Ministry of Environment and Forestry, 66.4% of municipal solid waste generated is simply landfilled, with 57% of landfills operating as open dumpsites, and 19.62% of waste is unregulated. Centralised wastewater treatment operates only in big cities and consists of only two stages. There are a huge number of targets to be met both in research and development, as well as in legislative and engineering fields. To create the sustainable municipal waste and wastewater treatment system in Indonesia, the Hungarian example and experience can be highly motivating and useful.

Iron has an essential role in forming hemoglobin in the blood, transporting oxygen from the lungs to the tissues, and transporting electrons during energy formation in cells. Iron deficiency can cause anemia that can lead to death. One of the methods to overcome iron deficiency is through iron supplements and micro quantities of iron in the diet. This study aimed to process industrial iron waste into ferrous sulfate through leaching with sulfuric acid. The resulting ferrous sulfate can be used as a material for iron fortification. Iron waste from a local workshop was dissolved in 20% sulfuric acid for six hours. The filtrate was filtered and crystallized to form ferrous sulfate. The product was analyzed for purity using the XRF. The results showed that the ferrous sulfate product had a purity of 99.01%.

Microalgae cultivation on a large scale requires large amounts of water and nutrients; this causes the cultivation process to be less economical. Tofu wastewater anaerobic digestion effluent (TWADE) from an anaerobic wastewater treatment plant (WWTP) contains nutrients that can be used as an alternative medium for microalgae cultivation to reduce cultivation costs. This study aimed to utilize non-sterilized TWADE as a low-cost cultivation medium for Chlorella vulgaris. Microalgae cultivation was carried out for ten days using TWADE 50% and 100%, with and without NaHCO₃ addition. Walne medium was used as a positive control, and tap water was used as a negative control. All mediums were diluted and prepared without sterilization, only cloth-filtered. The physicochemical characterization of non-sterilized TWADE showed that TWADE contained nitrogen, phosphate, potassium and some trace minerals such as Fe, Cu, B, Mo, which were potential nutrients for microalgae growth. The results revealed that Chlorella vulgaris cultivated in TWADE had higher cell counts, protein, chlorophyll a, chlorophyll b and carotenoids than the negative control. However, microscopic observations found some protozoa, which was suspected of causing Chlorella vulgaris growth disorders. In general, TWADE has potential as an alternative cultivation medium, but further studies are required to find an easy and inexpensive strategy for contaminant removal.

Municipal solid waste management is one of the biggest challenges in many world cities today. Indonesian government policies through Presidential Regulation No. 35/2018 to process waste into electricity through environmentally friendly technology should be supported. Waste-to-energy (WTE) incineration can destroy waste quickly and significantly and has the opportunity to create a circular economy through recycling efforts and the use of renewable energy. Bantargebang WTE plant was built as a learning center for national experts to master the thermal conversion technology. The plant was designed to process 100,000 kg of waste per day with an electricity output of 700 kW. This paper describes the results of research on the circular economy potential of Bantargebang WTE by observing operational data between August and November 2020. During the period, the plant combusted a total of 4,212,300 kg or 52,000 kg/day of waste with an electricity output of 7179.3 kWh/day. In addition to electricity, the circular economy potential was obtained from recycled waste materials, the use of fly ash as paving blocks, and carbon credit from the avoided carbon emissions. The circular economy model at the Bantargebang WTE plant would be useful in developing a circular economy in other WTE plants to be built in Indonesia.