Study of sustainable solid waste management system of Carocok Beach Painan tourism area using Life Cycle Assessment (LCA) method

This study aims to assess the environmental impact and compare two scenarios of the solid waste management system of the Carocok Beach Tourism Area using the Life Cycle Assessment method. System boundaries include operational and technical aspects of waste management, the energy required, and emissions generated. The functional unit is 30.546 kg/day of waste treated. Scenario 1 is the existing conditions using a city-scale approach with a 1% reduction of waste at the source by scavengers, using a collection of motorized pedicabs, applying transportation to landfills by arm roll truck, and processing Integrated Solid Waste Treatment Plant by composting and landfilling with controlled landfill operation. Scenario 2 is the planning system with different phases of waste processing at the Recycling Center by composting and recycling with plastic chopping machines, producing handicrafts, and practices of sanitary landfill on landfilling. The impact assessment method uses the CML-IA method. The impact categories studied are Global Warming Potential (GWP), Acidification Potential (AP), and Eutrophication Potential (EP). Scenario 2 showed the best scenario because it has a smaller impact value for the three impact categories. However, to become a more sustainable management system, some improvement options recommended include a substitution of collection and vehicle fuel and waste processing using the Takakura method.


Introduction
Population growth is one of the main factors in increasing the amount of waste generation.The waste problem seems simple and easy to solve.However, it turns out that the waste problem is a problem that needs special handling.This condition is because waste is related to all human, animal, plant, and biological activities-the more volume of waste increases, the more diverse the composition.The Ministry of Environment and Forestry stated that the national waste generation amount is 175,000 tonnes per day or the equivalent of 64 million tons per year if using the assumption that 0.7 kg of waste is generated per day per person [1].
IOP Publishing doi:10.1088/1755-1315/1306/1/012040 2 Solid waste will cause environmental pollution.According to [2], environmental pollution is the entry or inclusion of living things, substances, energy, and other components into the environment by human activities to exceed the established environmental quality standards.Environmental pollution can occur anywhere, such as in tourist objects.
In Pesisir Selatan Regency, a tourist attraction is Carocok Beach Painan with Cingkuak Island in IV Jurai District.The existence of these tourist objects has resulted in creating jobs around tourist attractions such as trading food or handicrafts.As a result of the emergence of these businesses, there is also the emergence of waste sources around tourist objects that will cause pollution.The attractiveness of visitors is reduced if waste is not a priority in managing tourist attractions.
Previous research has been conducted in the Carocok Coast and Cingkuak Island Tourism Area, analyzing data on generation, composition, recycling potential, and waste characteristics.The composition of the waste obtained is organic waste consisting of food, plastic, paper, textile, yard, and wood waste by 80.51% and inorganic waste consisting of glass waste, non-ferrous metals, and others by 19.49%.The potential for recycling of food waste is 47.454%, plastic 86.248%, paper 24.018%, non-ferrous metals 93.550%, glass 54.887%, and wood 10.984% [3].
Moreover, further study was conducted to plan sustainable solid waste management for the tourism area of Carocok Beach Painan.The existing condition of the Painan waste management system still applies to the collect-transport-waste system.The solid waste of the Tourism Area of Carocok Beach Painan has not received full attention from the Pesisir Selatan District Government and the limited facilities and infrastructure available.Therefore, the study conducted to design the management system of the Carocok Painan Beach tourism waste, which used a 120-liter volume bin, collection using a motorized pedicab with a capacity of 1.5 m 3 , the waste processing facility at the recycling center using a compost chopper, and 11 Takakura bins [4].To ensure sustainable solid waste management system practices, an assessment of the environmental impact is a requirement by Indonesian Constitution Number 18 of 2008 concerning Solid Waste Management.
One of the environmental management tools for impact assessment is Life Cycle Assessment (LCA).The LCA method has been used to assess the environmental impact of products and services in various sectors, including municipal solid waste management [5].LCA is a tool for evaluating the environmental impact concerning resource use, human health, and ecology.LCA can be used to design and develop commercial products and services in communities and countries [6].LCA is applied to analyze the better waste management strategies between landfill without biogas utilization; landfill with biogas combustion to generate electricity; sorting plants that split the inorganic waste fraction from the organic waste fraction, and direct incineration waste [7].Another study applied LCA to compare different scenarios of municipal solid waste technologies: landfilling, direct incineration, anaerobic digestion, and direct gasification.This study reveals that the direct gasification scenario had the best environmental profile [8].Therefore, it is necessary to assess the environmental impact of the existing solid waste management system and the planning system to address a better system for the future environment.This study aims to assess the environmental impact and compare two scenarios of the solid waste management system of the Carocok Beach Tourism Area using the Life Cycle Assessment method.

Methodology
The research analyzed the potential environmental impact on the Carocok Beach Painan Tourism Area's waste management system, the existing practice, and the improved planning system.This study is divided into several steps: literature reviews, primary and secondary data collection, and LCA study.
The literature review aims to learn the theoretical basis related and directly related to the study.Literature studies collect data from related agencies and study theories from various textbooks, journals, and associated regulations.
Primary data was collected through interviews with key informants to obtain information about existing waste management at Carocok Painan Beach and recommendations for waste management solutions.Related parties are the Head of the Section for Cleanliness at the Public Work Agency of Pesisir Selatan Regency, the Carocok Beach Area Cleanliness Supervisor, and landfill site employees.The secondary data collected include the technical and non-technical aspects of the Carocok Beach tourism waste management system, from [4]; Materials involved (energy and fuel requirements); and Equipment needed during the processing process; LCA consists of four stages [9].Firstly goal and scope definition.It guides the consistency of LCA research.The objective should indicate the reasons for the study and the purpose.If there is much data available, limitations must be carried out for the research to be more focused and on target.The second phase is the Life Cycle Inventory (LCI).This stage is carried out by collecting data that can support LCA analysis called inventory data.Some inventory data is already available in the SimaPro database.If information is not available in the SimaPro database, measurements can be carried out, such as generation, emissions, energy, and others.If both methods are not obtained, the data from other journals that discuss the same topic can be used.
Third, the Life Cycle Impact Assessment (LCIA).The impact assessment method used in this study is the CML-IA method.This step consists of impact classification and Impact characterization.Impact classification in this study includes Global Warming Potential (GWP), Acidification Potential (AP), and Eutrophication Potential (EP).This classification was chosen since many related studies use the same categories.Impact characterization provides a way to directly compare LCI results in each impact category.Impact characterization also determines the magnitude of the classified impacts, both quantitatively and qualitatively.This LCA analysis uses SimaPro 9.0 software as the popular software used by many researchers and industries globally.
The last step is Life Cycle Interpretation.Interpretation aims to identify, evaluate and conclude the environmental impact analysis of the waste management system in the Carocok Beach Painan Tourism Area assessed in the previous stage.Interpretation is carried out based on the analysis results of SimaPro software.Then, consider which set of the waste management system has a significant impact on all scenarios and compare several scenarios to determine the best scenario.Contribution analysis is to determine the contributors to the significant impacts at a system stage and improvement analysis contains recommendations for improving the existing system to become a more environmentally sound system.

Solid waste generation, composition, and recycling potential
The waste generation used was based on the projection done by Aziz et al. [4] as 30.546kg/day.The composition of the waste obtained is organic waste consisting of food, plastic, paper, textile, yard, and wood waste by 80.51% and inorganic waste consisting of glass waste, non-ferrous metals, and others by 19.49%.The potential for recycling food waste is 47.454%, plastic 86.248%, paper 24.018%, non-ferrous metals 93.550%, glass 54.887%, and wood 10.984% [3].The potential for recycling the waste in the Carocok Beach tourism area in Painan City that can be recycled is 52.857%, while the waste that is not suitable for recycling is 47.143%.The most significant recycling potential is found in iron waste due to iron waste.The second most significant potential for recycling waste is plastic waste in drink bottles from visitors and merchant waste.Meanwhile, compostable waste reached 6.71% of the total waste from food waste.3.2 Solid waste management scenarios 3.2.1 Scenario 1. Scenario 1 is the existing condition applied by Carocok Beach.In its implementation, the area and service level of waste in the Carocok Beach Tourism Area only reached 64.53% and 76.86% service level.Garbage in the Carocok beach area comes from the trash of visitors and traders around Cingkuak Island.Waste that can be recycled, segregated, and utilized by the informal sector, in this case, is the scavengers by 1%.This percentage is obtained from interviews with supervisors at Carocok Painan Beach, and calculations are carried out to get the percentage.The types of waste recycled by scavengers include plastic bottles, hard plastic, and cans.The existing waste management scheme is shown in Figure 1 Figure 1.Scenario 1 (Existing) waste management scheme.[4] research planning and adding some modifications.In planning, solid waste service in the Carocok Beach Tourism Area is 100%.The waste management plan is to build the recycling center near the communal container location of Carocok Beach containers.Compost processing using the Takakura method and inorganic waste in plastics, paper, and wood is resold and made into crafts and souvenirs.Transportation to the landfill site is only the residual waste from the recycling center using the same transportation equipment as the existing conditions.The landfill site is different from scenario 1, a sanitary landfill.An increase made from [4] research planning is the informal sector (scavengers), recycling with plastic chopper machines, and piling up waste at the landfill site using the sanitary landfill method.The recycling center's processing activities are added to plastic waste recycling with a plastic chopper to improve waste processing at the recycling center.Recyclable waste is segregated and utilized by the informal sector (scavengers) by 1% of the total waste generated.Types of waste recycled by the informal sector (scavengers) include plastic bottles, hard plastic, and cans.The planning waste management scheme shows in Figure 2.

Interpretation Impact Comparison.
The impact comparison of two scenarios of the three impact categories shows in Figure 5. Impact comparison of GWP shows that in considering global warming potential, scenario 1 is higher than scenario 2. This condition is mainly due to the high volume of CH4 discharged into the environment.The volume of CH4 comes from the waste in the landfill site.When considering air emissions between the controlled landfill and the sanitary landfill, the highest CH4 emissions are issued.Other impacts of global warming originate from emissions from transportation and collecting equipment and chopping machines.For total HC and total NMVOC emissions, this is due to the decomposition of organic matter in the landfill.Meanwhile, for AP, acidification in scenario 2 has the highest impact value than other scenarios because landfill site with the sanitary landfill method emits more air emissions such as HCl, HF, NH4, NOx, SOx, and metals.This value is due to the electricity generation process and more diesel fuel than in scenario 1.These emissions are also found in emissions from transportation means and collectors.The results of the EP comparison showed that in considering the eutrophication potential, scenario 1 is higher than scenario 2. The analysis indicates that scenario 1 has a significant contribution to the potential for eutrophication.This impact is due to the high amounts of nitrogen (N) and phosphorus (P) involved in eutrophication at the landfill site.Meanwhile, the number of PO4 in the sanitary landfill is higher than in the controlled landfill.The high PO4 emission is caused by the increased consumption of electric energy and diesel fuel.However, the amount of waste landfilled in the final disposal in scenario 2 is less, resulting in less impact of PO4.
Impact Contribution.From impact contribution, it can be seen that the emission contributors for each stage are described as follows: a. Stages of the collection process Emissions contributing to the transport collection process are CO, NO2, CH4, and NOx assessed in the impact categories GWP, AP, and EP.CO2 is the most considerable emission contributor to this process.Emissions in this collection transport impact the environment even though the impact value is not too large.Emissions released are in the form of air pollution caused by motorized pedicab engines.b.Informal sector process stages -collector dealer Emissions that contribute to the delivery of recycled waste from the informal sector are CO2, CO, NO2, and NOx, assessed in the impact categories of GWP, AP, and EP.Emissions from transportation by motorized pedicabs impact the environment even though the impact value is not too large.Emissions released are in the form of air pollution caused by motorized pedicab engines.c.The composting process stages Emissions that contribute to the composting process are CO2, CH4, and NO2, assessed in the impact category of GWP, AP, and EP.The more composted waste, the opportunity to contribute to emissions from composting is getting bigger because more and more waste is processed.Emissions from chopping engines and sieving machines also provide emissions of air pollution when the engine is started.d.Recycling process stages In Scenario 2, the recycling process is carried out by plastic processing waste into plastic ore with this process causing emissions into the air in the form of NOx, NO2, and a little from CH4. e. Stages of the transport process Not much different from the collection process.Emissions contributing to the transportation process include CO, NO2, CH4, and NOx, assessed in the impact categories GWP, AP, and EP.CO2 is the most considerable emission contributor to this process.Emissions from collection transport impact the environment even though the impact value is not too large.Emissions released are in the form of air pollution caused by truck engines.The distance between the trucks and the landfill will affect the size of the impact.f.Stages of compost-consumer-delivery and recycling-consumer-delivery processes Emissions that contribute to compost delivery and waste recycling include CO2, CO, NO2, and NOx, assessed in the impact category of GWP, AP, and EP.Emissions from transportation by motorized rickshaws and trucks also affect the environment even though the impact value is not too large.Emissions released are in the form of air pollution caused by motorized rickshaw engines and trucks.g.Landfill process stages The landfill process contributes the most significant environmental emission compared to the previous stages.The highest CH4 was emitted from the controlled landfill because there was no methane gas management.However, fossil CO2 emissions are released more in sanitary landfill.Air emissions such as HCl, HF, NOx, SOx, and metal are released into the environment more in the sanitary landfill because they are caused by generating electricity and diesel fuel, which includes heavy equipment and transportation.PO4 emissions are also primarily released in sanitary landfills due to high electrical energy consumption and diesel fuel.BOD and COD in leachate using the sanitary landfill method was less because leachate was well controlled.
IOP Publishing doi:10.1088/1755-1315/1306/1/01204010 Improvement Analysis.The characterization results in the previous stage show that scenario 2 is the best alternative because it has a smaller characterization value than other scenarios.Scenario 2 has carried out processing at the source, the recycling center, such as composting and waste recycling.After being analyzed using the LCA method of waste processing, which was initially expected to reduce environmental impacts, it still impacts every process that uses energy-generating equipment.So, it is necessary to increase improvements and alternative solutions in minimizing the impact on the environment.The following are some of the recommendations put forward for the selected alternatives:

Collection and transportation process
The collection and transportation process does not significantly impact all scenarios because it has a negligible impact characterization value for each impact category.The impact of the collection and transportation process contributes to consuming fuel from the collection and transportation.Long distances also cause the emission issue to be even more significant.
Recommendations for reducing the number of emissions generated are changing the route taken by finding the closest route to the landfill site or the recycling center.Garbage transportation uses arm roll trucks to replace fuel with B30 fuel.The quality of B30 is the same as 95% pure diesel, and it is more environmentally friendly because the efficiency of combustion and exhaust gas emissions is cleaner [10].In addition to changing fuel, it is also recommended to improve motorized rickshaw transportation and arm roll trucks, such as changing the oil regularly and checking the exhaust gas content every 6 or 12 months.

Processing at Recycling Center
Alternative processing carried out at the recycling center is composting.The more organic waste processing, the more composting emissions will be produced, with aerobic composting obtaining an odorless compost product faster than the anaerobic process.Aerobic composting can reduce the volume and produce less CH4 emissions.Composting using the Takakura method with an aerobic process is an alternative solution because it can reduce providing composting equipment.The compost results were obtained with a texture that is not wet, has volume shrinkage, brownish color, and is odorless.The application of the Takakura method can overcome land limitations.Communities around the coast can also apply this method because the compost processing method is easy and can be applied at a household scale.
Besides, Pertamina Dex fuel can replace compost and plastic chopper machines.[11] has analyzed this Pertamina Dex for diesel engines and obtained a comparison of the average emission produced by diesel fuel is higher than Pertamina Dex.There is an increase in the higher engine's power, and the engine acceleration is much lighter when using Pertamina Dex.So, from the results of this study, it is recommended to replace diesel fuel with Pertamina Dex.In addition to changing fuel, it is also recommended to improve diesel engine maintenance, such as changing the oil regularly to be used for the long term.

Landfill process
Reducing waste generation to landfills can be done by routinely socializing visitors, traders, and local communities instead of consuming plastic.Familiarize ourselves with the use of environmentally friendly materials and equipment.The recycling center is optimized for waste processing so that the waste generation that is carried and dumped to the landfill site is reduced.The sanitary landfill operation contributes less to eutrophication, global warming, and photochemical oxidation impacts.At the same time, open dumping has potential impacts in the categories of global warming, ozone layer depletion, photochemical ozone formation, and human toxicity through the soil because it does not apply techniques to control emissions of gas and leachate [12].To minimize environmental impacts in the form of GWP, AP, and EP on the sanitary landfill method, here are some improvement solutions, namely: a. Perform processing technology for the gas produced.Landfill gas processing uses processing technology with a flaring system or converting it to power plants.According to the [13] research, gas processing with an open flare and enclosed flare system can reduce methane gas by 50% and 90%.[14] stated that landfill gas processing technology with flaring is more feasible from economic and technical aspects than being left alone or used for power generation.It requires investment costs, operation, and higher maintenance.b.The application of leachate treatment technologies such as microfiltration and nanofiltration can be used to reduce the concentration of COD, TSS, and Fe [15].It is better than conventional processing methods (collecting ponds, anaerobic ponds, aerobic ponds, and sedimentation ponds).c.Another alternative is to increase leachate processing using a coagulation model of leachate treatment and anaerobic biofilter.According to [16], the COD parameters, BOD, TSS, and NH3 in leachate can be reduced by a significant amount from 90% for COD and BOD and less than 90% for NH3 and TSS parameters using coagulation and anaerobic biofilter models.

Conclusion
The conclusions of the research results of the LCA study on the waste management system in the Carocok Painan Beach Tourism Area are Classification of the potential impacts of the three selected scenarios, namely GWP, AP, and EP.The most significant impact value is GPW, and the smallest impact value is EP, and The best scenario is scenario 2 because it is environmentally feasible with the lowest potential impact value to other scenarios and the last Some improvements in solid waste management related to shorter transportation routes, truck fuel substitution, applying the Takakura method using an aerobic process, and replacing diesel fuel with Pertamina Dex, and the landfill process applies the sanitary landfill.

Figure 5 .
Figure 5. Impact comparison GWP (a), AP (b), EP (c).Impact comparison of GWP shows that in considering global warming potential, scenario 1 is higher than scenario 2. This condition is mainly due to the high volume of CH4 discharged into the environment.The volume of CH4 comes from the waste in the landfill site.When considering air emissions between the controlled landfill and the sanitary landfill, the highest CH4 emissions are issued.Other impacts of global warming originate from emissions from transportation and collecting equipment and chopping machines.For total HC and total NMVOC emissions, this is due to the decomposition of organic matter in the landfill.Meanwhile, for AP, acidification in scenario 2 has the highest impact value than other scenarios because landfill site with the sanitary landfill method emits more air emissions such as HCl, HF, NH4, NOx, SOx, and metals.This value is due to the electricity generation process and more diesel fuel than in scenario 1.These emissions are also found in emissions from transportation means and collectors.The results of the EP comparison showed that in considering the eutrophication potential, scenario 1 is higher than scenario 2. The analysis indicates that scenario 1 has a significant contribution to the potential for eutrophication.This impact is due to the high amounts of nitrogen (N) and phosphorus (P) involved in eutrophication at the landfill site.Meanwhile, the number of PO4 in the sanitary landfill is higher than in

Table 1 .
Life cycle inventory.Inventory data shows in Table 1.Inventory data 7 3.3.3ImpactAssessment.The impact category used is GWP, EU, and AP.Impact characterization determines the magnitude of the classified impacts.Impact characterization also compares the inventory analysis results in each impact category.The results of the impact characterization showed in Table2.

Table 2 .
Characterization of the impact of each scenario.