THE EFFECT OF TYPES AND SIZES VARIATIONS OF MARKET ORGANIC WASTE IN COMPOSTING USING BLACK SOLDIER FLY LARVAE (BSFL)

Purpose: Organic waste processing can be done through composting. This study aims to see the effect of variations in the types and sizes of market organic waste in composting using Black Soldier Fly Larvae (BSFL). Theoretical framework : Market-generated organic waste needs to be handled without harming the environment. Composting is the proper method for treating organic waste from markets. BSFL is one of the organisms that can be utilized as a catalyst for the breakdown of organic waste. In many ways, using BSFL as an agent to break down organic materials is a profitable recycling technique. When it comes to waste management, BSFL can transform a variety of organic waste types, including animal manure, boosting the organic waste's value as a recyclable resource. Method/design/approach: Market organic waste composting using BSFL. This composting uses several variations. The variation of this study consisted of six variations. Variation 1 (100% of fruit waste with manual chopped), 2 (100% fruit waste with machine shredded), 3 (100% vegetable waste with manually chopped), 4 (100% vegetable waste with machine chopped), 5 (65% fruit waste + 35% vegetable waste with manual chopped), and 6 (65% fruit waste + 35% vegetable waste with machine chopped). Results and conclusion: Compost analysis was carried out on the maturity, quality, and quantity of compost produced. A scoring system selects the optimum variation with the best variations obtained from variations 1 and 5. The highest waste reduction index and reduction rate were obtained from variation 1 as 6.755 % and 94.571%. Research implications: Utilization of BSFL as a market organic waste decomposition agent into compost that has a selling value or is used to fertilize plants. Originality/value: Effect of variations in types of waste (fruit waste and vegetable waste) and waste size on composting using BSFL.


INTRODUCTION
Solid waste is a matter that becomes a major problem in various countries. The projection of world waste in 2050 is predicted to reach 3.40 billion tons (Kaza et al., 2018). The increase in this problem is in line with the growth in the country, both population growth, economy, and technology (Minghua et al., 2009). As much as 93% of the waste generated by developing countries mostly contains >50% biodegradable waste. Inadequate management of biodegradable waste will have a negative impact on the environment such as producing greenhouse gas emissions that contributes to climate change (Ferronato and Torretta, 2019).
In Indonesia, the amount of waste in 2020 reached 67 million tons and was dominated by 60% (40 million tons) of organic waste originating from market waste, as much as 17.94% (7 million tons) (KemenLHK, 2020). The market is one of the sources of urban waste. Buying and selling activities in the market contribute to the increase in the volume of waste. The total waste originating from traditional markets is 17.18% of 33 million tons (KemenLHK, 2020). 3 The generated waste needs to be processed, not just dumped in landfills. Organic waste has chemical and biological characteristics that are suitable for processing by the composting method (Dewilda et al., 2019;Dewilda et al., 2022;. Composting is a decomposition process of organic material by utilizing microorganisms in a controlled environment with the final result as hummus and compost (Jurado et al., 2015). One method of treatment organic waste that has been widely used in Indonesia is composting using Black Soldier Fly Larvae (BSFL) or Hermetia illucens (Sastro, 2016;Muhayyat et al., 2016;Nirmala et al., 2020;Mursaid et al., 2004;Nursaid et al., 2019;Pathiassana et al., 2020). The advantages of composting using BSFL are that they can convert various organic materials and can live in environments with a wide pH range. BSFL are also easy to breed because they are not easily affected by the season. BSFL are able to consume food quickly into compost and biomass rich in protein and fat (Sastro, 2016). BSFL flies are also not classified as pests and are not founded in residential areas so they are safe for human health .
Composting using BSFL has a mechanism for efficiently converting organic waste into compost (Sheppard et al., 1994;Setti et al., 2019), besides this process produces fat-rich larvae which are suitable for animal feed (Newton et al. al., 1977;St-Hilaire et al., 2007) and biodiesel production Zheng et al., 2011). BSFL has the advantage of being able to be reared on different substrates , such as fruit waste (Nguyen et al., 2013) and food waste (Diener et al., 2011;Nguyen et al., 2015), as well as fish waste (Lalander et al., 2013;Bank et al., 2014).
Several studies have been conducted using different methods to increase the biodegradability of substrates to increase conversion by BSFL Li et al., 2015;Rehman et al., 2017;Pathiassana, 2020;Dormans, 2015). Such as adding other substrates such as rice straw and restaurant waste (Zheng et al., 2012;Li et al., 2015). Moreover, variations in the type of waste in bioconversion using BSFL affect the compost yield (Pathiassana, 2020). BSF larvae more easily break down waste into small pieces or even slurry (Dormans, 2015).
Biological handling of market waste using BSFL is a new invention in waste management (Cˇicˇková et al., 2015). The use of BSFL can be a quick way to deal with biodegradable waste (Kumar et al., 2018), so the BSFL method is a waste treatment method that is feasible to apply . Therefore, this study was conducted to determine which types and sizes of waste produce better compost in terms of composting time, quality, and quantity of BSFL composting.

Market Waste
Market waste is waste originating from all activities in the market. Market waste is according to Law Number 18 of 2008 concerning Management of Household Waste and Household-like Waste is classified as household-like waste. Of the many sources of waste generation in Indonesia, the percentage of generation generated by the market sector reaches 17.1% of the total 28.69 million tonnes of waste generated (SIPSN, 2021). Market waste has an organic waste composition of up to 90%, with a compostable organic waste composition of 82.6%. The dominance of organic material in market waste will affect the characteristics of the waste, such as the water content reaching 73.31% (Fadhil, 2017). The composition of the waste and the resulting characteristics affect the waste processing method (Iswadianto, 2018).
The processing of market waste in Indonesia can be said to be not optimal. Research by (Arifin, 2018), regarding waste management at Kurai Taji Market, South Pariaman, explained that the organic waste produced is only stacked in a container and then transported to the TPA 4 without any processing. The existence of organic waste that is not managed can cause problems ranging from aesthetics, smell and emergence of disease vectors (Axmalia & Mulasari, 2020). Proper processing of market organic waste is through composting. In addition to avoiding aesthetic, odor and environmental health problems, composting also has economic benefits from the final product it produces.

Composting Using Black Soldier Fly Larvae (BSFL)
One of the organisms that can be used as an agent for decomposing organic waste is BSFL. Organic waste is used by BSFL as a food source during the larval phase. The bioconversion process uses a reactor container as well as a larva breeding vessel. Organic waste can be given every day until the larvae are not actively eating or reach the stage (pre-pupae). The results of decomposition by BSFL are also called maggot residues (kasgot), which can be used as compost (Dortmans et al., 2017). Composting using BSFL is able to convert 100% of organic waste by producing 60-70% compost and 30-40% into protein-rich larval body weight (Sastro, 2016).
The use of BSFL as an agent for decomposing organic matter is a profitable recycling method in various aspects. When viewed in terms of waste management, BSFL can convert various types of organic waste, even animal manure, thus increasing the recycle value of the organic waste (Kim et al., 2011). Research by (Diener, 2011), shows that BSFL are able to reduce organic waste by up to 78.9%, depending on the amount of waste given and the availability of a drainage system in the decomposition reactor.
The ability of BSFL to decompose organic matter is supported by their digestive enzymes. This ability is obtained due to the high levels of digestive enzymes found in the mouth of BSFL compared to their digestive glands (Kim et al., 2011). BSFL have more varied digestive enzymes, such as the enzymes leucine arylamidase, α-galactosidase, β-galactosidase and α-mannosidase so they are able to process organic waste properly. The use of BSF larvae in reducing organic waste must pay attention to the following factors (Sipayung, 2015): 1.
Dietary habit of BSF BSFL generally have the characteristic of eating in a horizontal direction with their food. Sometimes the BSFL also move vertically to extract nutrients in the leachate resulting from the decomposition of the given organic waste.
2. Availability of sufficient oxygen in the reactor BSFL equire sufficient amounts of oxygen and cannot live in conditions with high CO2 levels. This causes the BSFL to leave the reactor and look for a source of oxygen even though the BSFL have not yet reached the pre-pupae phase.
3. Moisture content The water content of the waste affects the consumption time of the larvae for the given waste. The optimum range of water content for BSF larvae is between 60-90%. Likewise with the presence of CO2, high water content will cause the larvae to leave the reactor to find a drier place. The low water content in the reactor also inhibits the process of decomposition of organic matter by BSFL.
4. Availability of light BSFL are classified as photophobic animals. During the larval phase, BSF tends to stay away from light sources and in the pre-pupa stage BSF will naturally come out of the reactor and look for a dark, dry place before turning into a cocoon.

Compost Quality Standards
Compost quality standards in Indonesia refer to SNI 19-7030-2004 concerning Compost Specifications from Domestic Organic Waste. Compost quality is assessed from several aspects consisting of physical elements, macro elements, micro elements, other elements and bacteria. Details can be seen in Table 1 SNI 19-7030-2004

Materials
The tools and materials used in this study include plastic containers measuring 42 cm x 32 cm x 14 cm, digital balance, sitting balance, a knife, a chopping machine, and stationery. The materials needed are market organic waste with a total of 3.5 kg for each research variation and 7-day-old BSF larvae weighing 50 grams for each reactor. Plastic containers can be seen in Figure 1.

Methods
The research was conducted in duplicate for each data collection and testing. The input process of market organic waste was carried out for 14 days. This study used six variations of composting using BSF larvae. The design of the research variation can be seen in Table 2. The amount of organic waste added to each reactor is based on a feeding rate of 100 mg/larvae/day (Diener, 2010), so using a weight of 1 larva is 0.02 grams, the amount of waste used is 250 grams per day. Composting using BSF larvae is done by placing seven days old BSF larvae in a composting reactor in the form of a box-shaped plastic container. The number of larvae in each reactor was 50 grams. Then the waste is given daily for 14 days at 250 grams/day. Then check for the first and last days regarding the temperature and pH of the compost. The residue produced after 14 days is composted, then weighed and tested for compost quality.
Compost quality testing is carried out to see whether the compost produced has met the requirements of the Indonesian standard for compost specifications from domestic organic waste (SNI 19-7030-2004). The compost quality test is carried out on several parameters. Measurement of C-Organic with the Walkey Black method, Nitrogen by Titrimetric, Phosphorus (P2O5) using the Spectrophotometric, and Potassium using the Atomic Absorption Spectrophotometer (AAS).
The compost quantity test was carried out by weighing the compost produced from each variation. Several aspects related to the calculation of the compost quantity can be seen as follows: Waste reduction index (WRI): Where D is total feed reduction(gram), W is total feed (gram), R is total feed remaining after a specific time (gram), WRI is waste reduction index (%/day), and t is total time larvae eat feed (days).
Reduction rate: Where A is the initial raw material weight (gram), and B is the final raw material weight (gram).
Data processing and analysis were carried out after all data was obtained, starting from the maturity, quantity, and quality tests of the compost produced. The selection of the best compost variation was carried out by a scoring method. The scoring system includes three criteria. Criterion 1, score 1, is given if the variation meets the quality standard of SNI 19-7030-2004. Parameters of criterion 1 are the parameters of the quality and maturity of the compost. For criterion 2, a score of 0 is given if the variation does not meet the quality standard of SNI 19-7030-2004. Parameters of criterion 2 are the parameters of the quality and maturity of the compost. Lastly, criterion 3 is used for parameters that do not have quality standards. Scoring is given based on ranking. The maximum score (6) is given to the variation with the highest and The value of the waste reduction index resulting from composting market organic waste using BSF larvae can be seen in Table 3. WRI values in each variation with composting using BSF larvae ranged from 6.694-6.755%. The highest WRI value was obtained from variation 1 of 6.755%. In terms of type, this study found that the type of waste did not significantly affect WRI. As for the size of the waste, the manual cutting process gave a higher WRI value than machine cutting. The higher moisture content influences the higher WRI in waste with manual cutting in machine cutting, so the process of larvae consuming organic waste is disrupted (Muhayyat et al., 2016).

Figure 2. BSF composting reactor condition variation 3 (left) and 4 (right)
The absence of WRI values produced by waste with 100% vegetables, either manually chopped or machine chopped, is due to the high amount of leachate produced in the reactor. The production of leachate in the reactor triggers a flooded condition. The high moisture content in the reactor inhibits larval body movements, so much energy is drained to move. The high waterlogging in reactors 3 and 4 resulted in a lack of oxygen supply. Moreover, it triggered the formation of CO2 so that the composting conditions turned anaerobic (Diener, 2010). This condition caused many larvae to die in variations 3 and 4, so the composting process could not continue. Reactor conditions 3 and 4 can be seen in Figure 2. The reduction rate shows the percentage reduction in the compost's initial and final weight. Data on the level of reduction of all research variations can be seen in Table 4. The percentage of waste reduction in each composting variation using BSFL did not show a significant difference. The highest reduction rate was in variation 1, with a value of 94.571%. The reduction rate in this study ranged from 93.714-94.571%. It is in line with the results of previous studies, which resulted in a reduced rate of 85-97% with the same type of waste (Nirmala et al., 2020). The higher level of reduction in the composting variation with BSF larvae indicates that the BSF method has advantages in processing market organic waste in terms of reducing organic waste.

Compost quantity scoring
The scoring on the quantity of compost produced can be seen in Table 5.

Composting Temperature Analysis
Temperature testing was carried out on each variation's first day, the last days of the composting process. Compost is declared mature according to SNI 19-7030-2004 if it has the same temperature as groundwater, which is <30℃. Changes in temperature from the first to the last day can be seen in Table 6. using BSF larvae ranged from 27-30℃. This condition is due to the addition of market organic waste carried out continuously daily (Nursaid, 2019). The addition of new organic waste also affects the composting temperature. BSF larvae will not survive at temperatures >36℃ (Tomberlin et al., 2009).

Analysis of pH
Measurements of pH were carried out every day during the composting process. Measurements were made before adding waste the next day. Changes in pH during composting can be seen in Table 7. The pH value in each study variation for 14 days of composting ranged from 4.5 to 7. Regarding the type and size of composting raw materials, there was no significant difference between the type of waste and the size of the organic waste used for the change in the pH of the composting. Measurement of pH for 24 days was carried out because there was no change in pH within three days.
The pH range of composting that resembles the pH of fresh waste is caused by the addition of organic waste carried out daily (Nursaid, 2019). The decrease in pH occurs due to the formation of organic acids during composting, which indicates the degradation process of organic matter into organic acids (Saragi dan Bagastyo, 2015). The change of organic acids causes an increase in the pH of composting into CO2 and the presence of alkaline cations resulting from the mineralization of organic matter (Li et al., 2007). Changes in pH during the composting process did not affect the growth of BSF larvae. BSF larvae have a wide pH tolerance of 0.7-13.7 (Fadhillah dan Bagastyo, 2020;Alattar, 2012).

Analysis of Texture
Composting texture analysis was carried out every day until the compost had a soil-like texture, following SNI 19-7030-2004. The results of the observation of the composting texture can be seen in Figure 3. Textures resulting from composting using BSF larvae tend to take a long time to reach the loose stage. This condition is due to the high moisture content stored in the reactor, and the drying method is carried out by aerating in a roofed room. The results showed that the variation of waste chopped by a machine took longer to achieve a soil-like texture. This condition is due to the high moisture content caused by machine cutting (Muhayyat et al., 2016).

Color Analysis
Color analysis was observed every day during the composting process. It stopped when the compost was declared ripe in color following SNI 19-7030-2004. The color change during composting can be seen in Figure 4.  Figure 3, the color change occurs from the color of the initial waste to brown. It is known that in variation 3, the color of the reactor only pays in the range of waste color (green) and brownish-green. This situation is due to the high moisture content of leachate waste production. The decomposition process and reduced moisture content cause color change during the composting process.

Odor Analysis
Analysis of the odor during the composting process was carried out every day until the smell of the compost resembled the odor of soil, following SNI 19-7030-2004. Observation of the smell of all variations can be seen in Figure 5. Each variation's odor during composting showed changes ranging from smelling fresh garbage, smelling bad, starting to smell of earth, and smelling like earth. Variations 1 and 2 had a fruity odor for 14 days of composting. This condition is caused by the frequency of feed that is done every day. The rotten odor produced in variations 3, 4, 5, and 6 is influenced by the composition of vegetables, which are dominated by cabbage, which will emit an unpleasant pungent odor when rotting. The high levels of nutrients in cabbage accelerate the decomposition of the vegetable (Rahmadi, 2003).

Composting Time
The length of time for composting is influenced by the method used and the type and size of organic raw material for organic waste. The composting time of each variation can be seen in Figure 6.  The longest composting time occurs in variation 2, with fruit waste and shredded machine variations. The time required for composting using BSF larvae is caused by changes in texture that take a long time due to the high moisture content produced using BSF larvae.

Compost Maturity Scoring
The recapitulation of the compost maturity score can be seen in Table 8. Variations 5 and 6 have the highest score regarding the compost maturity level compared to other variations, worth 10 points. Meanwhile, the lowest variation resulted from variations 3 and 4, with a score of 2. Regarding maturity level, the optimum variation between the composting method and BSF larvae was obtained from variations 5 and 6.

Compost Quality Result
The parameters of the compost quality test were carried out on the content of nitrogen, carbon, C/N ratio, potassium, and phosphorus. The results of this study indicate that all variations have met the standard of SNI 19-7030-2004. The details can be seen in Table 9. The C/N ratio is one of the critical aspects of nutrient balance (Purnomo et al., 2017). The C/N ratio in this study has met the standard, which means it can be used as compost. Compost with a C/N ratio greater than 30 will interfere with the nitrogen content when applied to the soil. On the other hand, compost with a C/N ratio below 20 will mineralize organic nitrogen into inorganic, suitable for plants (Sarpong et al., 2019).
The quality standard for Potassium, according to SNI 19-7030-2004 is 0.2. Meanwhile, the minimum value of phosphorus in compost is 0.1. The measurement of P and K levels in all variations showed that the results had met the SNI quality standard. The content of N influences the high level of P in the compost produced. The higher the value of N, the higher the microbial multiplication in remodeling P, and the higher the P content of the compost produced (Hidayati et al., 2011). Potassium plays an essential role for plants as an enzyme activator (Baroroh et al., 2015). The scoring of compost quality can be seen in Table 10. The compost quality score shows a 1 for the overall variation in each parameter. This condition happens because all variations have met the parameters required by SNI 19-7030-2004 related to C, N, C/N, P, and K levels.

Determination of Optimum Compost Variation
The scoring system determines the optimum compost variation. The variation with the highest total value is the optimum variation. The recapitulation can be seen in Table 11. Based on Table 11, the highest scores were obtained by variations 1 and 5. Meanwhile, the lowest score was obtained from variations 3 and 4 as 9. This situation was influenced by the treatment of variations 1 and 5 with manual cutting, which resulted in lower moisture content than the variation with machine cutting. Meanwhile, the type of waste affects the quality of the compost produced. The composting process in variations 3 and 4 is disrupted due to the vegetable waste used, which decomposes quickly to produce leachate, triggering aerobic conditions in the reactor. The result of variation 6 showed that it is promising to mix the waste material of vegetables and fruits with machine cutting. The results of this study can be applied in the processing of market waste produced. In addition to plastic waste (Massuga et al., 2022) and food waste (Salim et al., 2021) which have negative impacts if not managed properly, market waste can also cause negative impacts, so composting using BSFL is a recommended solution in processing market organic waste. Because BSFL has been proven to be able to process organic waste well (Sarpong et al., 2019;Wang et al., 2020;Isibika et al., 2021;Liu et al., 2019).

FINAL CONSIDERATIONS
By the research results, all research variations have complied with the national standard of Indonesia for compost specifications from domestic organic waste. Except for the pH and textures for various types of vegetable waste, both manually and by machine. The best composting variation was obtained from variations 1 and 5. The type of waste affects the composting process, especially the physical elements. Vegetable waste is easily decomposed, so the composting reactor has a strong smell and cannot produce compost. Lastly, the size of the waste also affects the composting process, where machine-chopped waste produces a higher moisture content which causes BSF larvae not to be optimal in consuming waste. For further research, high water content can be anticipated by adding rice bran and it would be interesting to compare the BSFL composting with other composting methods, such as the Takakura bin method, which is also popular in the community because it is easy to practice. This research is useful in the academic field in scientific development in the treatment of market organic waste. If this waste is treatment using BSFL, it will produce economic value or for plant nutrition, and can reduce waste that goes to landfill.