PERFORMANCE EVALUATION OF THE BIOLOGICAL UNIT PROCESS FOR FECAL SLUDGE SUPERNATE TREATMENT (CASE STUDY: IPLT MADUREJO SLEMAN REGENCY, SPECIAL REGION OF YOGYAKARTA)

: IPLT Madurejo is located in Sub-village Tinjon, Madurejo Village, Prambanan District, Sleman Regency, DIY. This IPLT was built in 2017 with a capacity design of 25 m3 /day. The existing condition shows that IPLT effluent from 2021-2022 has not met the quality standards of Minister of Environment and Forestry Regulation No. 68 of 2016. Therefore it is necessary to evaluate the technical processes so that the effluent meets quality standards. The method in this evaluation is carried out through evaluating existing conditions with design criteria and recommendations, both in terms of operational and process aspects of each stabilization pond unit, namely evaluating technical criteria, evaluating capacity, evaluating efficient removal of treatment, evaluating IPLT operations and planning on alternative unit designs. The average influent discharge of IPLT Madurejo from 2021-2022 is 29 m3 /day, of which the planning design capacity is 25 m3 /day. Therefore, IPLT Madurejo has an overload capacity of 4 m3 /day. The alternatives are to add similar pools with the same volume as well as adding Holding Tanks, Grease Traps, and disinfectant pools can be used as recommendations to increase the performance of IPLT and have a high probability of successful operation.


INTRODUCTION
In their daily lives, humans produce domestic wastewater.Domestic wastewater is wastewater produced from various forms of household activities (Sulistia & Septisya, 2019).Most Indonesians still use the local household wastewater treatment system (on site system) in the form of septic tanks.
The discharge of liquids and solids (feces) even though it has gone through processing in septic tanks but still has a high organic content as a material that has the potential to pollute the environment, considering that fecal waste has a BOD (Biological Oxygen Demand) value, TSS (Total Suspended Solid) value and a large amount of coliform bacteria.In addition, the presence of fecal waste can also cause social problems, namely in terms of aesthetics, unpleasant odors, and human health impacts.(Sefentry & Masriatini, 2021).
The Madurejo fecal sludge treatment installation (IPLT) operated in March 2019, this STP is located precisely in Sembir Hamlet, Madurejo Village, Prambanan District.Fecal sludge treatment is designed using a combination of solids-liquid separation units, liquid fraction treatment units and sludge drying units (solids fractions).The series of units in the IPLT consist of SAP (Sludge Acceptance Plant) units, equalization pools, dewatering units and stabilization ponds consisting of aeration, facultative and maturation pools, and mud drying basins.
This fecal sludge treatment plant has been operating but has not been optimally shown by the effluent value from laboratory test results obtained based on the latest analysis, which is December 16, 2022.Sample testing showed: aeration pond with BOD (101.4 mg/L), COD (199.1 mg/L), Total Coliform (5800 Jml/100 mL), facultative pool with BOD (91.8 mg/L), COD (180.5 mg/L), Total Coliform (5200 Jml/100 mL) maturation pool with BOD (56.3 mg/L), COD (113.5 mg/L), Total Coliform (3400 Jml/100 mL), while based on quality standards of the Minister of Environment and Forestry Regulation No.68 of 2016 concerning Domestic Wastewater Quality Standards states that BOD5 value of 30 mg/L, COD of 100 mg/L and Total Coliform 3000 Jml/100 mL and The volume of fecal sludge entering per day exceeds capacity, which is 29 m3/day based on the results of the author's survey on December 16, 2022, in which the planned discharge is 25 m3/day of Madurejo STP.Therefore, it is necessary to evaluate the stabilization pool.On this occasion, the author underlines the problems that arise in the fecal waste treatment system, namely effluent from the STP stabilization pond which is not in accordance with the quality standards of the Minister of Environment and Forestry Regulation No. 68 of 2016 concerning Domestic Wastewater Quality Standards.The construction of the STP is expected to accommodate depleted fecal waste before being discharged into the environment so that it does not cause health problems and environmental comfort and make efforts to improve the performance of the Fecal Sludge Treatment Plant (IPLT).The construction of this STP is useful to anticipate worse impacts due to an increase in the volume of fecal waste and is also expected to deal with the problem of fecal waste effectively.Therefore, this study raised the title "Performance Evaluation of the Biological Process Unit for the Treatment of Fecal Sludge Supernatants (Case Study) of the Madurejo Fecal Sludge Treatment Plant (IPLT), Sleman Regency, Special Region of Yogyakarta".

RESEARCH METHODS
The method used in this study is measurement and calculation, which is obtained through observations at the Madurejo STP including the data collection stage and the data analysis stage.These data will be processed further until the level of fecal sludge concentration is known in accordance with its existing conditions.Further analysis is carried out by comparing the calculation of existing conditions with the ideal calculation of the design of the processing unit because the incoming discharge conditions are not in accordance with the design of the processing unit.

Kondisi eksisting IPLT Madurejo
The research was conducted at IPLT Madurejo which is located in Tinjon Hamlet, Madurejo Village, Prambanan District, Sleman Regency, Yogyakarta Special Region.The sludge treatment at IPLT Madurejo applies a pond system treatment, using a combination of solids-liquid separation units, liquid fraction treatment units and sludge drying units (solids fractions).The series of units in the STP consist of SAP (Sludge Acceptance Plant) units, Equalization Pools, Dewatering Units, Liquids enter the stabilization pond consisting of Aeration, Facultative and Maturation Pools, while solids enter the Sludge Drying Bed.
The management of fecal sludge waste at IPLT Madurejo uses a local sanitation system (On site Sanitation) where fecal waste is handled using local government trucks and private assistance.The process of fecal sludge treatment at IPLT Madurejo can be seen in the scheme below in Figure 1 below:

Gambar 1. Diagram Unit Proses Pengolahan di IPLT Madurejo
These sludge samples were taken on March 6, 8, 10, 2023 (High entry truck variation) and March 20 -April 13, 2023 (residence time variation of each treatment unit).In a day, IPLT accommodates as many as 12-19 fecal truck tanks with a capacity of 2000-4000 liters originating from the Sleman Regency area covering the Kalasan, Berbah and Sleman areas.

Analysis of Discharge and Dimensions of IPLT Madurejo
The Madurejo Fecal Sludge Treatment Plant (IPLT) has a built-up capacity of 25 m3/day in 2017.The current condition in 2023 is that there are fecal suction trucks at the Madurejo STP, there are two (2) types of trucks, namely trucks from the private sector with a capacity of 2 m3, and Environmental Agency (DLH) trucks with a capacity of 4 m3.Within the Sleman Regency there are 49 suction truck entrepreneurs with the average ownership of suction trucks is 2 trucks with a suction truck capacity of 2 m3.While the Environmental Agency (DLH) fecal truck has 5 suction trucks with a suction truck capacity of 4 m3.

Analisa Unit Aerasi
The aeration unit at IPLT Madurejo is built in concrete with open conditions and is square-shaped has dimensions Length (m) : 6.92, Width (m) : 9.87 and depth (m) : 2.50 and freeboard 0.4 (m), For dimensional analysis of aeration ponds can be seen in the following table.

Biological Oxygen Demand (BOD)
The effluent value of BOD in the variation of the first sampling of the

Ammonia
Ammonia is sourced from urine, feces and microbiological oxidation of organol substances derived from nature (Patty et al., 2020).High ammonia levels cause unpleasant odors, can lead to excessive growth of lichens and microalgae called eutrification (Mariyana et al., 2015).In table

Maturation Pool
To optimize the performance of the maturation pool, several improvements are needed, among others.Periodic draining of the pool is carried out for at least 1 year accompanied by the installation of sludge draining pipes and the addition of a pump unit to suck sludge deposits and cleaning scum foam, organic and inorganic waste on the surface of the pond.

Addition of Processing Units
The addition of a processing unit in the form of a grease trap before the stabilization processing unit and the addition of a disinfection pool after the maturation pool.

Grease Trap
Oil and grease removal using grease traps is carried out at the beginning of the processing system to prevent interference with the next processing unit.In general, grease traps consist of two compartments (Dhuha, 2020).The first compartment serves to set aside different types of solids in the waste: solids with a specific gravity heavier than water will settle while solids with a specific gravity lighter than water Wastewater that comes out of the maturation basin is flowed into the chlorination bath and spiked with chlorine compounds at a certain dose and time so that all pathogenic microorganisms can be killed (Said et al., 2013).

CONCLUSION
From the research that has been done, it can be concluded as follows: The overall performance of the processing unit has not met the applicable criteria and is less than optimal, judging from: The allowance efficiency on the parameters of BOD, COD, TSS, Fatty oil and total coliform test still exceeds the quality standards of Minister of Environment and Forestry No. 68 of 2016.The discharge of fecal sludge entering the Madurejo STP is 29 m3 / day exceeding the capacity with the design of the fecal sludge treatment unit.The design of the Madurejo IPLT processing units mostly meets the design criteria, but the operation and maintenance of the processing units have not run well.Recommendations for improving the performance of the STP stabilization pool include: Carried out by adding SOPs or operating instructions for the IPLT unit.Briefing to workers about IPLT operations so that IPLT operations can run according to procedures.The addition of laboratory facilities or laboratory personnel in the IPLT area, so that monitoring the quality of processing of each unit can take place regularly.Addition of a pumping unit to drain sludge accumulated in the treatment unit.

BIBLIOGRAFI
Fecal sludge testing at each treatment unit is carried out to determine the effectiveness of the ability of IPLT to remove pollutants contained in fecal sludge.Effluent quality checks were carried out through sampling with two variations, namely carried out in the first week of March 2023 based on secondary data of many fecal trucks entering the Madurejo STP on March 6, 10 trucks, March 8, 13 trucks and March 10, 7 trucks and the third week, samples were taken based on the residence time of each unit of the Madurejo STP stabilization pool.Fecal sludge analysis was carried out at the Environmental Engineering laboratory of the Yogyakarta Institute of Technology to test wastewater parameters which include BOD, COD, TSS, pH, Fatty Oil and Total Coliform and refer to the quality standards of domestic waste Minister of Environment and Forestry No. 68 of 2016.Chemical Oxygen Demand (COD) The COD test was carried out with two variations of sampling, which was carried out in the first week of March 2023 (based on secondary data, namely when the most fecal trucks entered the Madurejo STP) and the third week, namely samples were taken (based on the residence time of each unit of the Madurejo IPLT stabilization pool).The efficiency of COD removal in the first sampling variation is the week of the most fecal trucks.On March 6, 2023 (10 trucks = 20 m3) shows that the Aeration Pool with non-peak hours has a removal efficiency of 71.23% and peak hours of 67.34%.Facultative pools with non-peak hours have a removal efficiency of 8.48% and peak hours of 24,55%.Maturation ponds with non-peak hours have a removal efficiency of 55.64% and peak hours of 57.60%.On March 8, 2023 (13 trucks = 26 m3) showed an aeration pond with non hours having a removal efficiency of 71.69% and peak hours of 58.50%.Facultative pools with non-peak hours have a removal efficiency of 29.70% and peak hours of 27.44%.Maturation ponds with non-peak hours have a removal efficiency of 56.34% and peak hours of 20.86%.On March 10, 2023 (7 trucks = 14 m3) showed an aeration pond with non hours having a removal efficiency of 49.65% and peak hours of 28.60%.Facultative pools with non-peak hours had a removal efficiency of 49.71% and peak hours of 63.17%.Maturation ponds with non-peak hours have a removal efficiency of 56.01% and peak hours of 59.97%.Based on the residence time of each processing unit (8 trucks = 16 m3) shows an aeration pond with a percentage of COD reduction of 5.67%.Facultative Pool has a removal efficiency of 79.12%.The Maturation Pool has a removal efficiency of 7.19%.It can be underlined the cause of the ineffective decrease in COD concentration caused by the capacity of incoming waste exceeding the planned discharge and characteristics of COD that are high or contain organic matter that is difficult to decompose (Suoth, 2016).However, the outlet results on the COD parameter are still above the quality standards of domestic waste Minister of Environment and Forestry No. 68 of 2016.

4. 13 .
The efficiency of ammonia removal in the variation of the first sampling of the aeration pond on March 6, 2023 (10 trucks = 20 m3) shows that the Aeration Pool with non-peak hours has a removal efficiency of -36.82% and peak hours of 0.02%.Facultative pools with non-peak hours have a removal efficiency of -71.74% and peak hours of 0%.Maturation ponds with nonpeak hours have a removal efficiency of -5.2% and peak hours of 0%.On March 8, 2023 (13 trucks = 26 m3) showed an aeration pond with non hours having a removal efficiency of -38.20% and peak hours of -4.5%.Facultative pools with non-peak hours had a removal efficiency of 13.01% and peak hours of 13.07%.Maturation ponds with non-peak hours have a removal efficiency of 39.26% and peak hours of 34.42%.On March 10, 2023 (7 trucks = 14 m3) showed an aeration pond with non hours having a removal efficiency of -155.87% and a peak hour of 1.9%.Facultative pools with non-peak hours had a removal efficiency of 30.87% and peak hours of -43.71%.Maturation ponds with non-peak hours have a removal efficiency of -19.98% and peak hours of 28.89%.Based on the residence time of each processing unit (8 trucks = 16 m3) shows an aeration pond with a percentage of ammonia reduction of -25.83%.Facultative Pool has a removal efficiency of 99.99%.The Maturation Pool has a removal efficiency of -6.22%.In the results of the ammonia concentration test in the processing of IPLT madurejo on average has a content below the quality standard, therefore although there are fluctuations in the results of ammonia laboratory tests, the laboratory test values are safe for the environment.Fatty Oils Oil and fat are the main components of foodstuffs that are also widely obtained in wastewater.The content of oil and fat substances is determined through wastewater samples with hexane (Arlina, 2018).Fats belong to organic matter that is fixed and not easily broken down by bacteria.Oil can get to wastewater, most of the oil floats in wastewater, but there is also oil that settles carried by sludge.The results of laboratory tests showed the results of testing oil and fat levels on a bribe of the fecal sludge treatment unit at the Madurejo STP.Oil and fat levels carried out with 2 variations of this experiment found a comparison of values with far different results.In variations based on the residence time of this experiment there was an increase in concentration in the facultative pool of high fat oil in the facultative pool indicated by the mud solids present on the surface of the pool But in the maturation pool there is a decrease in concentration.This high fat oil content is caused by the large amount of wastewater left over from kitchen activities that enter or are mixed into the septic tank which is then sucked up by the fecal tank truck so that there are high levels of oil and fat marked by deposits on the surface of the pool.High levels of oil and fat will interfere with the life of organisms in the water, this is because the oil film on the surface of the water will block the diffusion of oxygen from the air into the water so that jumlah oksigen terlarut didalam air menjadi berkurang aeration unit can operate optimally and sustainably, so from the evaluation of the aeration unit above, Performance Evaluation Of The Biological Unit Process For Fecal Sludge Supernate Treatment (Case Study: Iplt Madurejo Sleman Regency, Special Region Of Yogyakarta) Page 458 Asian Journal of Engineering, Social and Health Volume 2, No. 7 July 2023 the procedures for operating the aeration unit can be formulated as follows: Periodic draining of the pool for at least 1 year is carried out accompanied by the installation of sludge draining pipes and the addition of pumping units to suck sludge and cleaning scum foam, organic and inorganic waste on the surface of the pool, And in aeration ponds, aerators require full time operational time so that the mechanical aerator system functions properly.Facultative PoolTo optimize the performance of facultative pools, several improvements are needed, among others.Periodic draining of the pool for at least 1 year is carried out accompanied by the installation of sludge draining pipes and the addition of pumping units to suck sludge deposits as well as cleaning organic and inorganic waste on the pool surface and monitoring the cleanliness of the pool so that there is no accumulation of sediment on the pool surface caused by high oil and fat levels(Hendrawan & Murase, 2008)

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Gambar 2. Skematik Grease Trap Some examples of the application of chlorine compound contactor units in wastewater treatment can be seen in Figure 3Chlorine compounds injected into wastewater can be in the form of solutions (liquids) or in tablet form.An example of the cross-section of a chlorine contactor bath with chlorine compounds in the form of chlorine in tablet form can be seen in the following figure.