Complexity of Waste Handling Technology at Final Disposal Site of Bantargebang, Bekasi City

Major problems at final waste processing sites (TPAs) include leachate, groundwater pollution, public health, and social aspects. Landfills are a major contributor to environmental damage in the world with effects on warming, acidification, smog formation, eutrophication, ecotoxicity and cancer to human health and non-cancer categories. Waste management in D.K.I Jakarta Province is currently facing a shortage of Integrated Waste Management Site (TPST) space with waste production reaching 7,000 to 7,500 tons/day. The main challenge in today’s municipal solid waste management is the selection of the most appropriate waste processing scenario, where the chosen method must be efficient and effective in minimizing leaching and emissions and reducing landfill waste, so that the service life of final disposal will be longer. Final disposal Bantargebang is the largest final disposal in Indonesia with an area of 132,5 Ha, where 80% is used for waste management and 20% of the land is used for support facilities. Final disposal Bantargebang implements various technologies in waste management including landfill, PLTSA, composting, and refuse-derived fuel (RDF) and involves scavengers in waste management at final disposal Bantargebang. The most dominant type of waste is food waste which reaches 39%. Various current technologies are still not effective, the implementation of sanitary landfills in final disposal Bantargebang is still very difficult to meet the planned design criteria, and tends to implement open dumping. This increases the potential for groundwater and surface water pollution and contributes to increased GHGs. Surface water in final disposal Bantargebang is highly polluted with COD and BOD parameters that exceed quality standards. Therefore, the multi-technology applied at final disposal Bantargebang only achieves an efficiency of 8% of incoming waste and the rest is still landfill waste in the landfill zone which is 92%.


Introduction
Globally nearly 2 billion metric tons of waste are generated daily [1], Nearly 70% of the world's solid waste is disposed of directly into landfills, while only 14% of the world's solid waste is managed by reuse and recycling [2].In developing countries, most of the waste management still uses conventional methods which are not environmentally friendly, that is, they are burned directly in open areas and some of the waste is still dumped directly into landfills without sorting and processing [1].After deposition, MSW undergoes physico-chemical decomposition due to microbial processes and then, produces leachate and landfill gas (LFG) [3].The main challenge in current municipal waste management is the selection of the most appropriate method, where the method chosen must be efficient and effective to minimize leachate and emissions and can reduce waste accumulation, so that the service life of final disposal site will be longer [4] Bantargebang final disposal site 'is the largest' final disposal in Indonesia and is adjacent to Sumur Batu final disposal [5].Bantargebang final disposal site located in Bekasi City with its main service area D.K.I Jakarta.Currently the final disposal Bantargebang receives 7,000 -7,500 tonnes of waste per day (upstdlh.id).Final disposal Bantargebang has been operating for 34 years since 1989, currently has an area of 132.5 Ha and has 5 landfill zones.At final disposal Bantargebang there are various types of waste processing that are already in operation including landfill, composting, incinerator, and refuse derived fuel (RDF), "as well as the role of scavengers in waste management at Bantargebang final disposal".
The operation of the final disposal has had an impact on the environment around the Bantargebang final disposal [6].The Bantargebang final disposal waste pile if simulated with the current situation will reach 36, 861, 653 tons in 2030.[7] the various technologies applied at Bantargebang final disposal have not been able to have a significant impact on reducing waste piles at Bantargebang final disposal, this must be supported by a thorough study to obtain the most suitable multi-technology scenario to be applied in Bantargebang final disposal management.This research will provide an overall picture regarding the existing state of Bantargebang final disposal which includes the technological capabilities available at Bantargebang final disposal to reduce waste generation and also its impact on the environment.As a reference for developing the most effective and efficient policies for the management of Bantargebang final disposal in the future.

Methodology and sampling
The research location is located at Bantargebang final disposal site in Bekasi City, final disposal Bantargebang "is located at 06•15′ South Latitude and 106•30′ East Longitude" [3].The Bantargebang final disposal area is located on an area of 132.5 Ha under the control of the DKI Jakarta government, covering 3 Sub-Districts namely Ciketingudik Sub-District, Cikiwul Sub-District and Sumurbatu Sub-District, as shown in figure 1. [1] The total area of the final disposal Bantargebang is 132.5 ha which consists of five areas or zones.The effective area of final disposal, namely the area used for landfilling waste, is 80% or 106 ha of the total land area, 20% or 26.5 ha is used for final disposal infrastructure such as entrances, roads, offices and leachate processing installations.This preliminary study was carried out through field observations and literature studies.Observations were carried out directly at each Bantargebang final disposal technology unit and literature studies were carried out by collecting reports from the Bantargebang Service Technical Implementation Unit, as well as literature studies in the form of journals from previous research.Interviews with scavengers dan final disposal Bantargebang manajement.The primary data needed in this study is data on the ability of each technology to manage waste at the final disposal Bantargebang, which then confirms the design criteria set by real operations in the field.Literature studies from this research were obtained from the final report on waste management at final disposal Bantargebang in 2022 and literature studies from various studies that have been carried out at final disposal Bantargebang."Primaryand secondary data collection were done by several methods, such as interviews, observation, and literature study.Table 1 shows the details of the data required during the study took place".The largest composition of waste is produced from 39% food waste, 33% plastic, 9% cloth, 4% hazardous waste, 4% wood and grass, 4% paper, 2% PET, and others 2%.Garbage at Bantergebang final disposal has a specific gravity of 0.20 kg/liter and a moisture content of 10.39%.Garbage at the Bantargebang final disposal has a specific gravity of 0.20 kg/liter with a moisture content of 10.39%.

Waste handling at final disposal Bantargebang
Waste management at final disposal Bantargebang implements various technologies such as landfills, composting, incinerators, and refuse derived fuel (RDF), as well as scavengers in reducing waste generation.Bantargebang final disposal also has supporting facilities for waste management at Bantargebang final disposal such as weighing bridges, power houses to capture methane gas from landfills and waste water treatment plants (WWTP).The following are the results of a literature review and direct data verification in the field regarding waste handling at the Bantargebang final disposal.

Landfill Final Disposal Bantargebang
Final disposal Bantargebang consists of 5 landfill zones, which have an area of 83.91 ha.final disposal Bantargebang implements a sanitary landfill system based on design criteria.[3], although in practice Sanitary landfill at final disposal Bantargebang is very difficult to do, because the red soil covering is difficult to obtain, so the landfill management system at final disposal Bantargebang implements more open dumping by covering using 30 cm red soil only when the landfill zone is closed.The final disposal Bantargebang receives 7,000 -7,500 tons of waste per day.Analysis results based on field data show that from 2019 to 2022, 36,861,653 tons of waste are generated.Thus the use of the final disposal Bantargebang should end in 2022 [2].
Improper management of landfills can have an impact on the environment, the most visible of which is groundwater and surface water pollution.The result of study [3] show that shallow groundwater pollution due to final disposal leachate in an area with a radius of 2km from Bantargebang final disposal reaches 33%.The surface water in Asem River, which is a surface runoff that crosses the Bantargebang final disposal, shows a heavily polluted status with COD and BOD values that exceed the quality standards.Landfill activity has the potential to produce landfill gas (LFG) such as methane (CH4) and carbon dioxide (CO2).The gas can cause an unpleasant odor and can disturb the environment [4].The landfill of final disposal Bantargebang is equipped with supporting landfill facilities including methane gas traps, a sanitation system for draining leachate and a wastewater treatment installation (IPAS).

"Landfill Gas (LFG)"
LFG "is gas produced from the drying process or anaerobic process of organic matter.Such as animal waste, human waste, domestic (household) waste, agricultural waste, plantation waste, etc.The main content (LFG) is methane (CH4) and carbon dioxide (CO2)" [3].At the final disposal Bantargebang, methane gas from the landfill is captured and used as fuel to drive a generator that stops being used as electricity in the powerhouse unit.The final disposal Banargebang powerhouse is a waste management support unit at final disposal Bantargebang where methane gas is taken from collective pipes planted in Zones I, II and V.The following is the gas produced from TPA with an anaerobic process which"can be seen in table"2.

Component
Composition % Methane (CH4) 45 -60 "Carbon Dioxide" 35 -40 "Nitrogen" 10 -25 "Oxygen" 0,1 -1 "Ammonia" 0,1 -1,1 "Hydrogen" 0 -0,2 "Carbon Monoxide" 0 -0,2 Based on the evaluation results of efforts to improve the power generation system using capping and also vertical pipes to accommodate methane gas at the final disposal Bantargebang, it can produce 19.6 MW in the first year and eventually decrease in the following years, until the twentieth year it only reaches 0.191 MW.This is caused by a damaged gasoline engine.the machine needs to be repaired by installing spare parts and carrying out further maintenance to minimize damage in the future [4].
CO2 reduction from the operation of the Powerhouse is 3.4 × 106 Mt/year.Revenue from sales of electricity is US$1.2×106 in the first year and 7.7×107US$ in year 15, respectively.Modeling studies at the Bantargebang TPA using LFG extraction data show that LFG production ranges from 0.05 to 0.40 m3 per kg of domestic waste stockpiled [1].Table 3. is the production data for Powerhouse units in 2022 of final disposal Bantargebang.based on the data above, the average electricity production from January to June 2022 generated from power houses is 678.853,333kWH.

WWTP (waste water treatment plant) final disposal Bantargebang
Final disposal Bantargebang has 3 WWTP units which are used to treat waste water from 5 landfill zones.leachate from zone 1 all flows into wwtp 1. wwtp 1 has an IPAS area of 1.7 Ha. leachate from zone 2, zone 4, and zone 5 flows into IPAS 2. wwtp 2 has an area of 1.0 Ha. leachate from zone 3 flows into WWTP 3 with an area of 1.2 Ha. Figure 8. shows the distribution of WWTP locations.The WWTP final disposal Bantargebang system uses an activated sludge system, which is a pond that is aerated with an agitator (high-powered stirrer).WWTP operations and drainage cleanliness need to be properly controlled every day so that there are no claims from the public about the quality of wastewater.Every day, WWTP final disposal Bantargebang manages leachate with an inflow of ± 150 m3/day and an outflow of ± 80 m3/day.The leachate comes from a landfill consisting of several zones at the final disposal Bantargebang.Each Landfill is installed with an underground pipe to drain leachate in the zone to the IPAS area.The following is a figure 9,10,11. of the state of IPAS I, II and III.

Refuse Derived Fuel (RDF)
Refuse Derived Fuel (RDF) is a product of flammable Municipal Waste fuel which has a high calorific value fraction to produce energy [5].The waste generated by DKI Jakarta has the potential to be used as RDF.The calorific value (CV) analysis between briquettes and RDF has a difference of 1815.8 cal/g.where briquettes have a calorific value of (8051.25 cal/g) and RDF has a calorific value of (9867.12cal/g).
The total amount of DKI Jakarta waste that can be made into briquettes is 5,253 tons/day in 2017.
Assuming an electricity production efficiency of 25% by using RDF, the electricity that can be produced is 12,288,529 kWh/day or can meet the electricity needs of 573,480 middle class household with electricity usage is 642.85 kWh/month [6].Population growth in 2021 the value of waste that can be used as RDF will also increase.In 2021, based on research conducted, it can meet the electricity needs of 905, 213 middle class household [10].In the final disposal Bantargebang the implementation of RDF is still on a pilot project scale where the waste that can be processed through RDF is 100 tons/day or 1.33% of the waste that enters final disposal Bantargebang every day.Figure 12 shows the results of the RDF pilot project scale with a size smaller than 10 mm or called wisteria and Figure 13 is a better RDF result after copped with a size smaller than 3mm or called metso.Final disposal Bantargebang plans to process 2,000 tons of waste per day in 2023.The Manning and RDF landfill units are located in an area of 7 ha.The waste processed at the unit consists of 1,000 tons from landfills and 1,000 tons from new waste from domestic activities.Landfill manning and RDF activities are expected to produce 700-750 tonnes/day of fuel as a substitute for coal which is utilized by the cement industry.

Waste to Energy (WTE)
PLTSa is a new division at final disposal Bantargebang which is a pilot project of the Agency for the Assessment and Application of Technology (BPPT).The electricity generated by PLTSa is used for electricity needs in the PLTSa Building.PLTSa in principle is a waste incinerator that uses combustion heat to produce steam which will drive a turbine that produces electricity (steam turbine gas).WTE final disposal Bantargebang is "planned to be able to burn 100 tons of segregated waste/day with an average calorific value of 1,500 kcal/kg and the electricity generated reaches 700 kW".This factory is also equipped with pre-treatment facilities to reduce moisture content and air pollution control devices so that the air quality produced does not exceed national standards.At the time this study was conducted, the WtE generator's electricity production was around 350 kW which was only used for the internal operational needs of the WTE generator.Under these conditions, the WtE plant burns an average of 65 tonnes of waste per day [4].During 2020, the plant burned 9,878 tons of waste and produced 784 MWh of electricity or an electricity conversion of 110.66 kWh/tonne of waste.exhaust gas and liquid waste emissions do not exceed national standards, Bantargebang WTE final disposal is an environmentally friendly WtE generator.Bantargebang WTE final disposal also produces fly ash and bottom ash of around 19.41% of the weight of the waste that is burned.
"the performance of the final disposal Bantargebang power plant.By using the Modified Triangular Method, the result is that the potential for electrical energy is 4.5 GWh.The calculation also estimates the emission reduction potential of 4325.88 tCO2/year" [8].
"Emission measurement data was analyzed using the Indonesian air pollution standard index regulations (PermenLHK P.14/2020).The CO, O3, NO2, PM10, and SO2 indices are in the good category (1-50), while the PM2.5 index is moderate (65,992).The results show that the air quality at the WTE final disposal Bantargebang"is still acceptable for human health [7].WTE electricity production in 2022 is shown in Table 4. Figures 14 and 15 show the WTE unit and pre-treatment WTE final disposal Bantargebang.

Composting
Organic waste from food scraps is the highest contributor to waste entering the final disposal Bantargebang.Food waste that enters the bantargebang landfill is up to 39% of the total incoming waste [2].Based on the type of incoming waste, waste processing with a composting system is considered effective in reducing the amount of waste in final disposal Bantargebang.Organic waste has a great impact on the final disposal Bantargebang landfill, organic waste can produce high levels of leachate and methane gas.The main problem with the composting unit is that the waste that goes to the final disposal Bantargebang is not segregated.The organic waste that is processed and processed at the final disposal Bantargebang is waste from the Kramatjati fruit and vegetable market.The composting facility at final disposal Bantargebang has not been running effectively, only running 10% of its capacity.By design the composting unit can reduce 1.428% of the total incoming waste or around 100 tonnes/day, but currently it is only capable of processing 10 tonnes/day of waste.Compost production currently running is only capable of producing 1-1.5 tons/day.The results of the existing compost production are used for greening the surrounding land, given to institution that need it.Based on Table 5, the production of the composting unit at the Bantargebang landfill in 2022 will be able to reduce an average of 284,200 tons/month of waste with a compost production of 42,630 tons/month.The final disposal Bantargebang composting unit also produces a residue of 241,570 tons/month which is then taken to the final disposal unit.

Bantargebang final disposal scavenger
There are 6,000 scavengers working at the Bantargebang final disposal, the majority of whom come from the people of Bantargebang District, and the area around Bekasi City, such as Indramayu Regency and Karawang Regency.There are 10% of those who are under 15 years of age or younger [14].[16].This income is still below the average minimum wage in Bekasi district.Bantargebang final disposal management collect data and provide insurance facilities to scavengers in final disposal Bantrgebang with BPJS Insurance [17].

Conclusion
The amount of waste that enters the final disposal Bantargebang every day reaches 7000-7500 tons / day.Leftover food waste is the dominant waste, reaching 39%.The final disposal Bantargebang land area is 132.5 ha with an effective area for use as a waste dump is 80% or 106 ha of the total land area, 20% or 26.5 ha is used as supporting facilities.Multi-technology applied at final disposal Bantargebang such as Landfill, RDF, Composting, PLTSA and the participation of scavengers in reducing waste generation at final disposal Bantergebang.The landfill system implemented at the final disposal Bantargebang is a sanitary landfill, but in practice it is still open dumping which is equipped with methane gas capture and leachate treatment facilities, one of the three existing WWTP has stopped operating.The effectiveness of the multitechnology applied at the final disposal Bantargebang has only reached 8% and the remaining 92% is still dominantly dependent on the landfill process.

Figure 5 .
Figure 5. landfill cover after operating using soil Figure 4. Landfill management final disposal Bantargebang

Figure 16 .
shows the location of the compost processing in the Bantargebang final disposal.

Figure 16 .
Figure 16.Compost area final disposal BantargebangFinal disposal Bantargebang processes organic waste by producing compost and implementing urban farming.The compost produced is processed from zone waste piles and waste sourced from fruit and vegetable markets.The composting process uses the aerobic method (open windows), the processing carried out by TST Bantargebang includes sorting, chopping, turning, sifting, temporary storage, and packaging.Table5shows compost production in 2022.

Figure 16 .
Figure 16.Bantargebang final disposal ScavengersScavengers at Bantargebang final disposal sort inorganic waste including plastic, paper and other inorganic waste.Scavengers at Bantargebang final disposal are able to reduce waste by as much as 4% of the total incoming waste or around 280 -300 tons/day.Scavengers at the Bantargebang fina disposal can produce 3,617.6tonnes of waste per month[15] with an average monthly income of a scavenger

composition of waste entering Bantargebang final disposal as shown in the following figure 2. Figure 2. Waste
[2]position Bantargebang final disposal[2]

Table 3 .
Electricity production from power house installations, January to June 2022

Table 4 .
Electricity production unit WTE

Table 5
shows compost production in 2022.

Table 5 .
Compost Production in 2022