Identification of waste composition in Shopping Centre X in Central Jakarta City

Waste is an unavoidable by-product of most human activities. Central Jakarta City is one of the administrative cities in the centre of the Special Capital Region of Jakarta, where Shopping Centre X is situated, a place relied on by the local community to serve their needs and to facilitate community activities. Shopping Center X has ±4,478 active shops which occupy all of its 9 floors, built on an area of 47,760 m2 and the waste generated varies. The purpose of this study was to identify sources of waste, before analysing the waste generation and composition in Shopping Centre X. The waste composition is an illustration of each component contained in the waste produced, and it can be used as a basis for determining a proper waste management in Shopping Centre X. Sampling was carried out using the SNI 19-3694-1994 method, where the waste measurement was made using a sampling box for eight consecutive days. The results of field research showed that, the waste composition in Shopping Centre X consists of 77.42% nonorganic and 22.58% organic waste components. The average rate of waste generation in Shopping Centre X is 3.58 kg/shop/day. The primary data collection was done directly, through field surveys and sampling. Waste samples taken were based on store category grouping on all the 9 (nine) floors, representing the number of samples in Shopping Centre X.


Introduction
The waste problem in Indonesia is quite a serious concern, due to the lack of public understanding of its consequences.Waste is an unavoidable by-product of most human activities, which are main factor in the ever increasing volume of waste generation.Waste management is about all measure taken in handling waste, right from the time it is generated, until its final disposal [1].Waste is the result of the remains of human activities.Waste can also be said to be items that are considered unused and thrown away by the previous owner, but for some people, trash can still be reused if it is managed using the correct procedures [2] Sources of waste, besides from residential areas, are public facilities, for example, shopping centres and malls [3].Central Jakarta City is one of the administrative cities in the centre of the Special Capital Region of Jakarta, which has a total population of approximately 1.5 million, with a volume of waste generation of about 884 thousand tonnes/day, disposed of to the TPST Bantargebang.
Shopping Centre X is a retail store complex and facilities, planned as an integrated group to provide shopping convenience to customers, with a maximally exposed arrangement of merchandise [4].Central IOP Publishing doi:10.1088/1755-1315/1263/1/012068 2 Jakarta City has a shopping centre that is relied on by the surrounding community for their daily needs and it also facilitates the community activities.Hence, it is necessary to identify the source and composition of waste generated in Shopping Centre X, so that, the waste management system can be enhanced.
The composition of waste is a description of each physical component contained in the waste and its distribution.These components include food scraps, paper-cardboard, wood, fabric-textile, rubberleather, plastic, ferrous-non-ferrous metals, glass, soil, sand, stone, ceramics, etc. [5].Generally, the composition of waste is classified into organic type, namely waste that contains organic compounds and can be decomposed by microorganisms, and inorganic type, which is waste that contains inorganic compounds, which are not easily decomposed by microorganisms [6].

Determination of the number of samples
Determination of waste sample data will be carried out based on SNI 19-3964-1994, namely sampling for 8 (eight) consecutive days.Shopping Centre X has a total of 4,478 active stores, which have been classified into 6 (six) categories namely, FT (Fashion and Textiles), EJ (Electronics & Clocks), FF (Foodcourt and Fastfood), AK (Gold/ Silver and Glasses), MP (Multiproduct), FU (Public Facilities)..The number of samples for each type of waste is divided using the slovin equation in Equation 1.
where, n = sample size N = store population size e = critical value

Sampling location
The sampling location in this study was on all the 9 (nine) floors of Shopping Centre X which is located in the city of central Jakarta, with the selected sampling areas representing the number of samples in Shopping Centre X.

Sampling equipment and supplies
The sampling activities, lasted for eight consecutive days, were done based on SNI 19-3964-1994 guidelines [7], as follows: (1) Plastic bags with a volume of 40 litres which had been labelled, according to the identified shops and kiosks, (2) The sample volume measuring tool in the form of a box with a size of 0.62 m x 0.41 m x 0.24 m, (3) Scales, (0 -50) kg and (0 -100) kg, and a measuring tape for measurement, (4) Equipment in the form of a transfer tool (such as a shovel), ( 5) Personal protective equipment, such as masks and gloves, (6) Stationery.Sampling activities were carried out after the business hours, for 8 (eight) consecutive days.

Waste generation sampling method and waste composition
Sampling was done, according to SNI 19-3964-1994, as follows: (1) Sampling was carried out for 8 consecutive days at Shopping Centre X; (2) Plastic containers, labelled with the type and location of the shops were provided, the day before sampling took place; (3) All plastic containers filled with waste were collected; (4) The waste was segregated, according to its composition, and the percentage of each waste component was calculated.

Data processing methods
The waste generation and composition data processing methods were based on SNI 19-3964-1994.The steps taken for processing generation and composition data are as follows: (1) A sample of waste generated was calculated, for each store category using a scale, for the 8 days of sampling.The measurement result for the volume of waste are in l/day and in terms of weight are kg/day; (2) The rate of waste generation (kg/store/day) was calculated using Equation 2; (3) The percentage of waste composition was calculated to obtain the weight of each organic and inorganic component.Waste samples were sorted and weighed, according to their compositions.The types of waste sorted included organic waste, plastic, glass/glass, paper, styrofoam, and residue (materials, lights, cables) [5].The calculation of waste composition was obtained by comparing the weight of each type of waste with the total weight of waste generated, using Equation 3.

Sources of waste generation
The sources of waste generation in Shopping Centre X were from several categories, namely, commercial waste, public and social facilities, which have been subdivided into 6 categories, namely, FT (Fashion and Textiles), EJ (Electronics & Clocks), FF (Foodcourt and Fastfood), AK (Gold/ Silver and Glasses), MP (Multiproduct), FU (Public Facilities).In shopping center X, each floor has been classified based on the categories and types of products, which can be seen in Table 1.

Determination of sample points
The sampling locations in this plan involved all the 9 (nine) floors in Shopping Centre X, with the selected sampling areas representing the number of samples in Shopping Centre X, X Shopping Center has 4478 active stores that have been categorized into 6 (six) categories, which can be seen in Table 2.

Waste generation calculation results
Measurement of waste generation was made from the sampling results for 8 (eight) consecutive days.This waste generation was obtained from the calculation of the waste generation rate obtained from the calculation of the total sample weight per type of store divided by the number of currently active stores, namely, 4,478 units.The results of the measurement of the waste generated in Shopping Centre X can be seen in Table 3.Based on the sampling results in Table 2, the waste source that produces the largest amount of waste is the FT (Fashion and Textiles) type of shop as much as 183.34 kg/day while the AK (Gold/Silver and Glasses) type of shop produces the least amount of waste at 5.20 kg/day with an average Store Sample Waste Generation at 3.85 (kg/store/day).The generation generated from all active shops at the time of sampling was 17,238.22(kg/day) where the type of shop waste that produced the largest waste was FT (Fashion and Textiles) as much as 12,842.05(kg/day).

Waste composition calculation results
Waste composition is the percentage of the amount of each type, divided by the total waste.In this journal, the results of calculations from 6 (six) categories were calculated as a whole, based on results in the field and showed the types of organic waste divided into 2 (two) compositions, namely, food waste and wood.Meanwhile, the non-norganic waste types were divided into 5 (five) compositions, namely, plastic, glass, paper, styrofoam and resdue.The waste in Shopping Centre X consists of 22.58% and 77.42% of organic type and non-organic, respectively, as shown in Table 4 and Figure 1.Based on the results of the sampling carried out, the composition of the waste obtained at shopping center X is plastic waste which has great recycling potential.Plastic waste can be processed into raw materials for making Refuse Derived Fuel (RDF), this processing is used to process inorganic waste such as plastic (PET/PETE, PP, OPP, PVC, HDPE, LDPE), paper (tissue, HVS, Duplex, Cardboard, Tetrapak cardboard), streofoam where the waste is sorted and then the results of the sorting will immediately be chopped and dried to become alternative fuel and will be resold.Meanwhile, organic waste can be processed into fertilizer, compost, maggot feed and maggot cultivation activities.

Conclusion
Based on the results of the discussion that has been done, in the preparation of this thesis the following conclusions are obtained: The average rate of waste generation in Shopping Centre X is 3.58 kg/shop/day, while the sample waste generation rates based on the type of shops are, 2.51 (kg/shop/day), 2.26 (kg/shop/day), 47.07 (kg/shop/day), 2.60 (kg/shop/day), 13.55 (kg/shop/day) and 5.00 (kg/shop/day) for FT, EJ, FF, AK, MP, and FU, respectively.The composition of waste at Shopping Centre X is dominated by plastic waste, 34.29% of the total waste weight.Inorganic waste forms 77.42%, while organic waste forms 22.58% of the overall waste composition.Alternatives that can be used to process non-organic waste are to make RDF as a substitute for coal and for organic waste you can carry out maggot cultivation activities.

Table 1 .
Shopping Center X floor use

Table 2 .
Determination of sample points.

Table 3 .
Waste generation in Shopping Centre X.

Table 4 .
Waste composition in Shopping Centre X.