The simple filtration unit in reducing parameters of restaurant wastewater

Restaurant wastes have high organic content that often pollute the environment. The filtration process is one method that can be done to reduce the restaurant wastes. The simple filtration process has been proven to be effective and capable of reducing contaminant contained in waste water. This study aims to determine the effectiveness of the simple filtration unit using some media for filtration and reducing some parameters of restaurant waste water. The Filtration experiment was carried out using variations in media with the thickness of 5, 10, and 15 cm. By using of media thickness with 15 cm given the best result in decreasing BOD, COD and turbidity (BOD was 93.4%, COD was 83.86%, and turbidity was 90.4%). The media thickness of 5 and 10 cm had given the best result of TSS parameter which was 99.22%. The media thickness of 5 cm also given the best result in oil and fat parameter, the result showed was 94.02%. The results of this study can be a solution in the treatment of restaurant liquid waste with the help of a filtration system.


Introduction
One of the environmental pollution comes from restaurant business activities [1].In accordance with consumer demand for ready-to-eat, varied and practical food, you can say that restaurant business activities are very developed in most big cities.The more the restaurant business develops, the more it increases waste generated.Therefore this will be one of the problems that must be considered.The most dominant pollutant in water bodies today is domestic wastewater, which is 60% to 70%.According to the Regulation of the Minister of Environment of the Republic of Indonesia Number 5 of 2014 concerning Wastewater Quality Standards, restaurant waste is classified as domestic liquid waste.
According to Government Regulation Number 82 of 2001 concerning Management of Water Quality and Control of Water Pollution, it is said that domestic waste needs to be treated first before being discharged into water bodies or into public canals so that it does not pollute the environment and must meet the quality standards set out in the Minister of Environment Regulation Life and Forestry of the Republic of Indonesia Number 68 of 2016 concerning Domestic Wastewater Quality Standards.In the restaurant waste to be treated, it was found that it contained parameter values that exceeded quality standards such as pH 6.1, BOD 500 mg/L, COD 1,500 mg/L, TSS 1,428 mg/L, oil and fats 9,308 mg/L, turbidity 1000 NTU.
The filtration system is one simple method that can be done in wastewater treatment.The filtration system is one of the tools in physical water treatment.The filtration process is a solidliquid separation by passing liquid through porous media or with materials that can remove or set aside fine suspended solids from the liquid [2].This physical filter functions to separate suspended particles (greater than 5 micrometers in size) from water by passing water through an 1263 (2023) 012053 IOP Publishing doi:10.1088/1755-1315/1263/1/012053 2 appropriate substrate so that it is able to capture the solids in the water before the water enters the holding container [3].The filtration system is able to remove suspended particles, one of which is by filtering assisted by a filter media as an absorbent for particles.In addition, the filtration unit is also able to remove odors in wastewater and remove bacteria effectively [4].

Methods
The samples taken in this study were at Pantai Perak Road, No.789, Kuta Alam, Kuta Alam District, Banda Aceh City.The process of checking the parameters of pH, COD, TSS, and turbidity is carried out at the UIN Ar-Raniry Multifunction Laboratory.The BOD and oil and grease measurements were conducted in the FMIPA Laboratory, Syiah Kuala University.

Reactor design procedure
The 3-inch PVC pipe has been cut into two parts (lengths of 44 and 37 cm).Each 3-inch PVC pipe was filled with filter media.The 3-inch PVC pipe measuring 37 cm was filled with filter media starting from the bottom, namely cotton and then activated carbon, while the 3-inch PVC pipe measuring 44 cm was filled with filter media starting from the bottom, namely zeolite and then silica sand [4].

Experiments
Restaurant waste water is first collected in jerry cans as much as 20 liters.Then, filter cotton media, activated carbon, zeolite, silica are filled vertically into the reactor with a predetermined media thickness.Variations in media thickness can be seen in Table 1.Samples of restaurant wastewater were put into a reactor.For each treatment, the contact time will be recorded.The filtered wastewater sample is then accommodated in a sample collection bottle for testing the parameters to be tested [5].

Data analysis
Data analysis in this study was carried out by measuring the effectiveness of reducing the parameters BOD, COD, TSS, oil and fats, and turbidity in restaurant wastewater after filtration treatment.According to [6], determining the effectiveness of parameter reduction will be calculated using the following formula: With : A0 = Pollutant level before processing An = Pollutant level after processing

pH value
If we see from the results of the initial pH measurement in Figure 2, the pH value is at 6.1 which indicates that it is still not in accordance with the quality standards in domestic wastewater.
Figure 2 shows the results after the filtration treatment, the water is still acidic at 6.0.

Figure 2. Graph of measurement of pH parameters.
Changes in the pH value that are not too far from each of these treatment variations are thought to be due to too high organic content in restaurant wastewater so that after measuring the wastewater the pH value does not increase to 7 (neutral).In the study of [7] the results of pH measurements before and after treatment using zeolite media and activated carbon did not affect changes in pH values either.So this shows that the treatment does not affect the pH value of the water.According to [8], acidic wastewater indicates that there are more hydrogen ions (H+) compared to OH-, the zeolite media has a negative charge which will bind to the positive charge in the wastewater so that the wastewater can become neutral.

BOD parameters
Based on Table 2 it shows that the results after the filtration treatment succeeded in reducing BOD levels.The results of the initial sample of wastewater before treatment were 500 mg/L which showed that it exceeded the quality standards about domestic wastewater.The BOD levels decreased that occurred was allegedly due to the influence of the use of several media, the high percentage of reduction in BOD levels was caused by the contact time and the thickness of the media used.According to [9], the contact time and media thickness affect the decrease in pollutant levels in wastewater.The longer the contact time in the filtration process, the better the attachment and absorption of particles will take place so that it can reduce BOD levels [10].In the study of [11], the thickness of 10 cm zeolite media can reduce BOD levels by 55.01%.
While in this study with a thickness of 10 cm zeolite media can reduce BOD levels by up to 80%.This is because the zeolite media can absorb solid particles in wastewater.Zeolite has a large surface area so it can absorb organic waste optimally [12].In addition, the decrease in BOD levels was also influenced by silica sand and activated carbon media.Both of these media have been proven capable of reducing pollutant levels in wastewater.According to [13], silica sand and activated carbon's ability as in doing processes of filtration, adsorption, and exchange of ions simultaneously to decompose and degrade organic matter in wastewater.

COD parameters
The COD content in restaurant wastewater decreased from variation 1 to variation 5 along with the addition of media in each variation.The percentage of reduction in COD values can be seen in Table 3.The decrease in COD in restaurant wastewater with variation 1 using 5 cm silica media, 5 cm zeolite, 5 cm activated carbon, 5 cm filter cotton has clearly seen a decrease with a value of 691 mg/L and an effective reduction of 53.93%.Meanwhile, the largest reduction with variation 5 used 15 cm silica media, 15 cm zeolite, 15 cm activated carbon, and 15 cm filter cotton produced a value of 242 mg/L and a reduction effectiveness of 83.86%.The COD levels were thought to be due to the zeolite and activated carbon media which work well.This was also revealed by [14], the use of activated carbon and zeolite filter media can absorb the pollutants contained in domestic wastewater (restaurants) so as to reduce COD levels.
In the filtration process, activated carbon and zeolite media function as separators and can remove micro pollutants from wastewater such as organic substances and detergents.The longer the waste is in the processing reactor, the greater the reduction in pollutant levels will be [15].In the study of [11] the percentage reduction in COD parameters using zeolite media with a thickness of 10 cm was obtained by a percentage of 51.04%.Whereas in this study in variation 3 which used zeolite media with a thickness of 10 cm, the percentage of reduction in COD levels produced was 75.13%.Although the final measurement results for variation 5 have not met the quality standards, the decline that has occurred has begun to appear to decrease from variation 1 to variation 5. COD levels that do not meet these quality standards are thought to be due to the effect of the medium used which is not thick enough.The thickness of the media greatly affects the decrease in COD levels, the thicker the media, the greater the decrease that occurs.This is presumably because the thicker the media, the more organic particles will be filtered by the media.According to [13], the thicker the use of silica sand and activated carbon media, the greater the

COD Effectiveness
reduction that occurs because the media has adsorb properties so that it is able to reduce COD levels.Activated carbon is able to reduce COD levels from 10% to 60% and zeolite is able to reduce COD levels from 10% to 40%, so that the efficiency of decreasing COD levels in activated carbon media is greater than in zeolite media [16].

TSS parameters
The TSS parameters showed that after the treatment there was a decrease in the thickness of the silka media 5 cm, 5 cm zeolite, 10 cm activated carbon, and 10 cm filter cotton (variation 2).The reduction in variation 2 has met the quality standard with a value of 11 mg/L and the percentage of effectiveness is 99.22%.In other media (variations 3 to 5), the TSS levels were higher and still above the quality standard.TSS levels are usually directly proportional to turbidity levels.According to [10], the higher the suspended solids content, the higher the content turbidity will also be higher.However, in this study it was not the case (Figure 5).Changes in the rise and fall of TSS levels are not always accompanied by a linear rise and fall in turbidity levels.The materials that cause turbidity consist of various materials whose properties and weights are different so that it does not really affect the weight of the TSS residue [17].The decrease in TSS levels in the restaurant's wastewater is thought to be due to the not too much TSS residue from organic waste.This is influenced by the media that works well.Cotton has the potential to reduce TSS levels because cotton is able to filter dirt/particles and small organisms in the water [18].

Oil and fat parameter
The initial yield of wastewater before treatment was 9.308 mg/L which was stated to still exceed the quality standards of domestic wastewater.After the filtration treatment was carried out, there was a decrease in the levels of Oil and Fat from variation 1 to variation 5 (Table 5).The decrease that occurred was visible from variation 1 and had met the quality standard, which was worth 0.556 with a percentage decrease of 94.02% so that it was declared to have met the quality standard ( 5 mg/L).Activated carbon is a medium that is often used in the filtration process and has been tested to be effective in reducing dissolved solids and organic matter in the form of oils and fats.According to [16] in accordance with the properties of activated carbon media that can adsorb organic matter so that it is capable in absorbing other molecules that have a smaller size than the pore size.The process of absorption of organic materials, especially oils and fats which have larger molecules, will cover the pores of activated carbon, making it difficult for smaller molecules to enter the pores [16].The decrease in the fatty oil content to meet these quality standards was also influenced by variations in the thickness of the media in each treatment, where the thicker the media the better the adsorption process that occurs.

Turbidity parameters
The decrease in turbidity levels is influenced by the media used, changes in odor and color also appear to be reduced.This is suspected by the silica sand media which can affect the decrease in turbidity levels and also odor.The final result obtained is 96.9 NTU with a reduction percentage of 90.4% (Table 6) and still exceeds the quality standards set by the Minister of Health Regulation Number 32 of 2017 with a value of 25 NTU.The turbidity level that does not meet the quality standard is thought to be due to the lack of thickness of the silica sand media used.According to [19], the thicker the media, the greater the decrease in turbidity, this is caused by the amount and duration of water passing through the media sand so that the thicker the silica sand media, the more pollutant substances will be filtered in the sand media.According to [18], grains in silica sand have pores and gaps so they are able to absorb and retain particles in water and can eliminate physical properties such as turbidity, mud and odor.Sludge trapped in silica sand can reduce odor and color in wastewater.Apart from silica sand, activated carbon is also known to be capable of removing contaminants and can reduce turbidity levels.

Conclusion
The final result of the pH parameter is acidic with a value of 6.The BOD parameter in variation 5 is 33 mg/L with a percentage of 93.04% and almost meets the quality standard (30 mg/L).The COD parameter does not meet the quality standard (100 mg/L), which is 242 mg/L with variation 5 and the percentage of effectiveness is 83.86%.The TSS parameter in variation 2 is 11 mg/L with a percentage of 99.22% and meets the quality standard (30 mg/L).The ML parameters in variation 1 with a value of 0.556 mg/L (percentage 94.02%) to variation 5 with a value of 0.092 (percentage 99.01%) have met the quality standard (5 mg/L).The turbidity parameter with a final value of 96.9 mg/L in variation 5 with a percentage of 90.4% and does not meet the quality standard (25 NTU).

Figure 3 .
Figure 3. Graph of measuring the effectiveness of the BOD parameter (%).

Figure 4 .
Figure 4. Graph of measuring the effectiveness of the COD parameter (%).

Figure 5 .
Figure 5. Graph of measuring the effectiveness of the TSS parameter (%).

Table 1 .
Variation of media thickness.

Table 2 .
The result of BOD parameters of restaurant wastewater before and after filtration treatments.After the treatment, there was a decrease in BOD levels from variation 1 to variation 5.The decrease that occurred in variation 5 almost met the quality standard, which was 33 mg/L with a reduction percentage of 93.4%.The quality standard stipulated in the Regulation of the Minister of Environment and Forestry of the Republic of Indonesia Number 68 of 2016 concerning Domestic Wastewater Quality Standards is 30 mg/L.

Table 3 .
The result of COD parameters of restaurant wastewater before and after filtration treatments.

Table 4 .
The result of TSS parameters of restaurant wastewater before and after filtration treatments.

Table 5 .
The result of oil and fat parameters of restaurant wastewater before and after filtration treatments.

Table 6 .
The result of turbidity parameters of restaurant wastewater before and after filtration treatments.
8 Figure 6.Graph of measuring the effectiveness of the turbidity parameter (%).