The improvement of Cipunagara River quality (BOD parameter) based on pollution load analysis of domestic,
3. Results and Discussion
The methodology of this study includes data collection, river segment selection, river status assessment, pollution load calculation and BOD simulation.
3.1. Segment Selection
As mentioned earlier, the selection of the segments is required to provide better accuracy of the study.
The criteria used for selecting the segments were the total area of the segment, number of population, number of industries, area of agriculture and existing water quality [22].
For each criterion, a 1-5 scale was given based on the ranking for each segment on the criteria, as there are five segments in Cipunagara River. Thus, at the end of the selection, each segment received five values representing all the criteria. The results from the assessment are shown in Table 2 and Table 3.
Based on the comparison in Table 2, the selected segment to be further studied is Segment 3 of Cipunagara River, which catchment includes 13 regions in Subang, Sumedang and Indramayu Regencies, as illustrated in Figure 1.
This segment dominates other segments to be prioritised in this study. It is also important to be noted that in Cipunagara Catchment, the government plans to build Sadawarna dan Cilame Resevoirs which requires the better river quality. These reservoirs will be used as the source of raw water to supply water needs of some cities and regencies in Cipunagara Catchment.
7th Sustain Conference in conjunction with 3rd ICGDTR 2018
IOP Conf. Series: Earth and Environmental Science 361 (2019) 012031
IOP Publishing doi:10.1088/1755-1315/361/1/012031
Table 2. Segments comparison based on the identified criteria Segment
1 2 3 4
Segment (Ha) 3,835 (3) 1,125 (2) 38,406 (5) 19,397 (5) Population 19,887 (3) 5,683 (2) 216,316 (5) 164,737 (4)
Number of Industries 8 (3) - (1) 14 (4) 68 (5)
Agriculture area (Ha) 672 (3) 229 (2) 11,230 (5) 12,877 (4)
Water Quality Lightly
Polluted (2)
Highly Polluted(5)
Highly Polluted (5)
Highly Polluted (5) Total Value for Each
Segment 14 12 24 23
Note: The values in the bracket is the assessment values for each criteria and segment
3.2. Calculation of Maximum Pollutant Load
The maximum pollution load was calculated by multiplying the maximum concentration for respective parameter with its flow. The results of the calculation are shown in Table 3.
Tabel 3. Maximum pollutant load for segment 3 of Cipunagara River.
No Parameter Unit Threshold
Class I
Maximum Pollutant Load (kg/d) Juli Agustus Oktober
1 TSS mg/liter 50 207,792 58,881.6 738,720
2 BOD mg/liter 2 8,311.68 2,355.26 29,548.8
3 COD mg/l 10 41,558.4 11,776.32 147,744
4 Total fosfat as P mg/l 0.2 831.16 235.52 2,954.88
5 Nitrat (NO3-N) mg/l 10 41,558.4 11,776.32 147,744
6 Amonia (NH3-N) mg/l 0.5 2,077.92 588.81 7,387.2
7 Nitrit (NO2-N) mg/l 0.06 249.35 70.65 886.46
8 Flow m3/s -
3.3. Existing Pollutant Load
The example for calculating of existing pollutant load of BOD from the Domestic Sector (Ciater District, Subang Regency) is as follow:
=
7th Sustain Conference in conjunction with 3rd ICGDTR 2018
IOP Conf. Series: Earth and Environmental Science 361 (2019) 012031
IOP Publishing doi:10.1088/1755-1315/361/1/012031
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Table 4. Pollution loads from all sectors
Sector BOD (kg/d) COD (kg/d) TSS (kg/d)
Total-
N(kg/d) Total-P (kg/d)
Domestic 1,361.35 1,871.86 1,293.29 66.37 7.15
Agriculture 1,265.59 - 2.03 112.47 56.23
Livestock 1,668.76 4,053.74 - 8.72 1.75
Industry 2,095.50 - - - -
Total 6,391.12 5,925.6 1,295.32 187.55 65.13
3.4. Comparison of Calculated Pollutant Load with Respective Maximum Pollutant Load
The calculated pollutant loads from all sectors are then compared with their respective maximum pollutant load, as shown in Figure 7.
Figure 7. Comparisons of pollution loads for each parameter
In general, the chart shows that for the parameters of BOD, the pollution load in Segment 3 of Cipunagara Catchment in August was above the maximum pollution load. This shows that combination of all the sectors (namely domestic, livestock, industry and agriculture) has given contribution to the pollution of Cipunagara River. Thus, the government and other stakeholders should work together for preventing the pollution in the future.
The figure also shows that in the month of October the pollution to Cipunagara River was below the maximum threshold. This is caused by the fact that during October, there is more rainfall compared to August. Therefore, the maximum threshold is higher as the maximum level was determined by the flow of the river. As the rainfall is higher, the flow of the river also increases.
3.5. BOD Simulation Model
Modeling simulation is carried out by observing the flow of pollutants in every pollution source points for BOD parameters. This modeling use is limited to BOD parameters. After data requirements are
- 20.000,00 40.000,00 60.000,00 80.000,00 100.000,00 120.000,00 140.000,00 160.000,00
TSS BOD COD Total-P
Existing Polllutant Load (kg/d) Maximum August Maximum October
7th Sustain Conference in conjunction with 3rd ICGDTR 2018
IOP Conf. Series: Earth and Environmental Science 361 (2019) 012031
IOP Publishing doi:10.1088/1755-1315/361/1/012031
completed, a schematic description of river pollutant sources is necessary. Figure 8. 26 describes the main river, namely Cipunagara, with 62.7 km in length, has several pollutant sources, contributing to the pollution of the river in every certain distance.
The pollutant sources are from 4 sectors: the domestic, agriculture, farming, and industry sectors.
However, due to the limited data/information on pollutant debit and concentration from the industry sector, this pollutant source is not analyzed in this modeling. The model predicts the pollution condition in 2021, that without control, the river will have pollutant burden that exceeds the capacity, similar to the existing condition in 2016. Only 5 from 15 BOD mixing points correspond with Class 1 water standard. This prediction will be used in pollution control considerations in surrounding areas in which pollution is still exceeding the capacity.
Figure 8. BOD model of segment 3 Cipunagara catchment
3.6. Proposed strategies
In general, the proposed strategies to improve the conditions of Cipunagara River are presented in Tabel 5. Due to limited space, the strategies presented in this paper are related to domestic pollution, while strategies related to other sectors will be discussed in other papers.
Table 5. Proposed strategies for the improvement of Cipunagara River
No Issues Strategies Programs
1 The discharge of domestic waste to the river
Preventing households to discharge wastewater to river without treatment
- Enacting regulations related to river pollution - Dissemination of river
awareness to communities
surrounding the river 2
There is no wastewater treatment plant (WWTP) in place
Encouraging the cooperation of
government and households to Initiating community- based project on WWTP -
2,00 4,00 6,00 8,00 10,00 12,00 14,00 16,00 18,00 20,00
BOD (mg/l)
Segments
BOD (mg/l)
Maximum Threshold Class 1
7th Sustain Conference in conjunction with 3rd ICGDTR 2018
IOP Conf. Series: Earth and Environmental Science 361 (2019) 012031
IOP Publishing doi:10.1088/1755-1315/361/1/012031
11
No Issues Strategies Programs
3
River banks are used for settlements (Tanjung Siang Cibogo and Gantar
Regencies)
Law enforcement to restore the river banks
Design the river banks to support the river quality, as well as for recreation areas
4
The rapid growth of population, thus increasing the discharge to the river
Control the population growth, particularly in the areas where pollution is already high
Relocation of population to less-densed areas