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Water Quality Index and Sediment Loading Analysis in Pelus River, Perak, Malaysia
Available online at www.sciencedirect.com
ScienceDirect Procedia Environmental Sciences 30 (2015) 133 – 138
International Conference on Environmental Forensics 2015 (iENFORCE2015)
Water quality index and sediment loading analysis in Pelus River, Perak, Malaysia Hasrul Hazman Hasana, Nor Rohaizah Jamila*, Norfadilah Ainia a
Department of Environmental Science, Faculty of Environmental Studies, Universiti Putra Malaysia, 43400 UPM Serdang, Malaysia
Abstract River can be considered as one of the main water, food source and habitat for all life forms. It is important to keep the health of river at an acceptable level for optimum function to support living being. The water quality index is used to assess the water quality condition in the river. Water quality index (WQI) and JPS River Index (JRI) can be used to monitor the health of the river. In this study, a total of eight stations along the main river were used for sampling. Six selected parameters (biological oxygen demand, chemical oxygen demand, dissolved oxygen, pH, suspended solid, and ammoniacal nitrogen) were used to calculate the water quality index. Parameters used to calculate JRI are specific flow, total suspended solid, total dissolved solid, and turbidity. Since sedimentation is a major threat in Pelus River, suspended solid concentration is used to find the sediment load in Pelus River. From the analysis, mean WQI in dry season (71.73) is higher compared to mean WQI in wet season (59.90). This indicates that the water quality during wet season (Class III-polluted) is a bit lower than the water quality during dry season (Class IIISlightly polluted). The sediment load in Pelus River per year is estimated to be 7.056 kg.ha/year during dry season and it is expected to be higher during wet season. The anthropogenic activities such as deforestation and agriculture were expected to influence the stability of the water quality in Pelus River. © Published by Elsevier B.V This ©2015 2015The TheAuthors. Authors. Published by Elsevier B.V.is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of organizing committee of Environmental Forensics Research Centre, Faculty of Peer-review underStudies, responsibility of organizing committee of Environmental Forensics Research Centre, Faculty of Environmental Studies, Environmental Universiti Putra Malaysia. Universiti Putra Malaysia. Keywords: Pelus River; Water Quality Index (WQI); JPS River Index (JRI); sediment loading; seasonal
* Corresponding author. Tel.: 03-89468499; fax: 03-89466766. E-mail address: [email protected]
1878-0296 © 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of organizing committee of Environmental Forensics Research Centre, Faculty of Environmental Studies, Universiti Putra Malaysia. doi:10.1016/j.proenv.2015.10.024
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Hasrul Hazman Hasan et al. / Procedia Environmental Sciences 30 (2015) 133 – 138
1. Introduction Pelus River is a cascading river; hence, the Tenaga Nasional Berhad (TNB) considered it as potential area to build a mini hydroelectric dam. Construction of hydroelectric dams can change the ecology of aquatic life, both at the upstream and downstream of the river and as well as give adverse effect in water quality [1]. Poor water quality may cause disturbance to the natural ecosystem, affecting the food chain, and can degrade population of aquatic life and wildlife [2]. Thus, it is crucial to keep the health of the river at an acceptable level. However, the actual condition of water quality in Pelus River need to be determined before any construction or development can be done. The essential of determining the health status of a river is by measuring the water quality of the river according to water quality index and JPS river index. The calculation of sediment loading is also important in estimating the amount of sediment in the future. There are many approaches that can be used to classify a river’s health. The most common analysis used are Water Quality Index (WQI) and Sediment Loading Analysis [3]. WQI is used in order to classify the river’s health status and sediment loading can be calculated by using the concentration of suspended solid [4]. Therefore, this study was carried out to fulfil two objectives: (i) To analyze the river quality status and classify the health of the river according to WQI and JPS River Index, (ii) To estimate the sediment loading of Pelus River, Perak. 2. Methodology 2.1 Study area The Pelus River catchment is a sub-catchment of the Upper Perak River, which flows from its source near the Thailand boarder, southwards through Perak State. The area has a humid tropical climate which is affected by the northeast and southwest monsoons, tropical winds that alternate during the course of the year. The humidity is about 80 % all year round and temperature range from 21 to 32 OC. The northeast monsoon blows from November to March, and the southwest monsoon from May to September. The periods between the monsoons are marked by heavy rainfall. The location of the study is taken along 22.11 km with 328.18 km2 of catchment area in Pelus River, Perak (Fig. 1). There were total of 8 stations cut across the downstream, middle stream, and as well as the upper stream. All these stations were served as the control stations to represent the actual condition of Pelus River. The samplings were conducted during two seasons; dry season (June 2014) and wet season (August 2014).
Fig. 1. Pelus River catchment Area and sampling stations
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Hasrul Hazman Hasan et al. / Procedia Environmental Sciences 30 (2015) 133 – 138
2.2 Sampling and Preservation Water samples were collected approximately 10 cm below the water surface using HDPE bottle. The samples were preserved by a few drops of nitric acid (to reduce pH until below 2) for COD and stored in an icebox and transported to laboratory for analysis within 48 hours. 2.3 Water Quality Index Analysis Water Quality Index method that is similar to Malaysia’s Water Quality Index method has been practiced in various countries. National Water Quality Standard (NWQS) is used as a tool for guidelines in maintaining Malaysia’s river water quality. The objective of NWQS is to create a benchmark of water quality for the protection and management of the surface water [5]. Six water quality parameters include dissolve oxygen (DO), Biological oxygen demand (BOD5), chemical oxygen demand (COD), suspended solid (SS), pH, and ammoniacal nitrogen (AN) were used to determine the Water Quality Index (WQI) for Pelus River. All of the parameters were multiply with their specific index: WQI=[0.22*SIDO]+[0.19*SIBOD5]+[0.16*SICOD]+[0.16*SISS]+[0.12*SIpH]+[0.15*SIAN]
(1)
The results from WQI were used to classify the water quality according to NWQS for Malaysia and the range for classes in WQI. 2.4 Sediment Loading Sediment loading can be calculated by multiplying the concentration of total suspended solid with the area of the watershed and the discharge from the watershed: Sediment Loading ሺ
୩Ǥ୦ୟ ୢୟ୷
ሻ= Concentration (mg/L)* Area (ha)* Discharge (m3/day)
(2)
2.5 JPS River Index (JRI) JRI can further classify the status of the river because the measurement of the river water flow and the catchment area of the river were taken into consideration in analyzing the JRI. Four sub-indexes include specific flow (SF), turbidity (Turb), total suspended solid (TSS), and total dissolve solid (TDS) were used for JRI calculation by using Sub- index of each parameters: JRI = 0.30*(SISF) + 0.13*(SITurb) + 0.35*(SITSS) + 0.22*(SITDS) Where, Specific flow, SF = flow (m3/s) / catchment area (km2)
(3)
3. Results and discussion 3.1 Water Quality Index (WQI) The status of water quality at sampling site was reflected on land activities within the catchment area. The calculated value of mean WQI for all sampling stations for each condition are shown (Table 1). Stations 1 2 3 4
WQI 73.93 72.7 71.98 74.58
Class III III III III
Table 1 River class and status Dry Status WQI Slightly polluted 88.60 Slightly polluted 54.57 Slightly polluted 57.24 Slightly polluted 54.06
Wet Class II III III III
Status Clean Polluted Polluted Polluted
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Hasrul Hazman Hasan et al. / Procedia Environmental Sciences 30 (2015) 133 – 138 5 6 7 8 Mean WQI
68.95 70.94 67.15 73.64 71.73
III III III III III
Slightly polluted Slightly polluted Slightly polluted Slightly polluted Slightly polluted
41.76 59.76 62.15 61.09 59.9
IV III III III III
Polluted Polluted Slightly polluted Slightly polluted Polluted
Index Value
WQI In Wet And Dry Season Limit for Clean River Status (81-100)
100 90 80 70 60 50 40 30 20 10 0
Limit for Slightly Polluted River Status (60-80) Limit for Polluted River Status (0-59)
1
2
3
4
5
6
7
8
Sampling Station WQI Dry Season
WQI Wet Season
Fig. 2. Comparison of WQI in dry and wet season
The calculation of WQI showed the water class for all station during dry season and wet season falls within the class III except stations 1 and 5 in the wet season which falls within class II and class IV respectively (Table 1). The lowest water quality during dry season was in station 7 (67.15) while the lowest water quality during wet season was in station 5 (41.76). The mean WQI, it showed during dry and wet season was class III respectively. However, the status of the river during dry season was considered as slightly polluted while the status of the river during wet season was considered as polluted. The water quality during wet season was more polluted compared to dry season. The main reason is that the pollutants had been washed away into the river by surface runoff [6]. Moreover, the land use activities such as land clearing and forest fire, and soil erosion usually take place before the wet season, thereby increasing the pollutants load in to river by flash out during wet season. This indicates that seasonal variation will affect the water quality of Pelus River [7]. 3.2 JPS River Index, JRI Since the class of JRI can be extrapolated by using the time factor in the calculation of specific flow, the JRI was conducted only in dry season. Downstream sampling station (station 8) was selected in the calculation of JRI. This is because station 8 believed to represent the concentration of all parameters in JRI for the whole catchment area.
Hasrul Hazman Hasan et al. / Procedia Environmental Sciences 30 (2015) 133 – 138 Table 2. River class and status according to JRI Parameter Unit Value JRI 87.51 Specific Flow, Non-rainy day (SF) m3/s.km2 91.12 Turbidity, Non-rainy day NTU 103.48 TSS mg/L 70.62 TDS mg/L 100.04
Class IIA I V IIIB IIB
137
River status Good Clean Very poor Fair Good
3.3 Sediment loading analysis The concentration of total suspended solid in station 8 was used as pollutant because suspended solid is closely related with sedimentation. Since the estimation of sediment loading was done for the whole catchment area of the river, the concentration of suspended solid at downstream (station 8) was used because eventually all of the suspended solid will accumulate at downstream, thus it represent the suspended solid for the whole catchment area[8]. The sediment load that Pelus River produced during dry season was 7.056 kg.ha/year. 3.4 Biodegradability (BOD/COD ratio) The biodegradability of Pelus River can be calculated by using BOD/COD ratio. BOD/COD ratio is considered as a good indicator of the proportion of biochemically degradable organic matter to total organic matter because BOD is a biochemical parameter and it will reflect the biodegradability of organic matter in the water [9]. The BOD/COD ratio during dry season was 0.2 and the BOD/COD ratio during wet season was 0.05 (Table 3). This indicated that the organic matter during dry season was slowly biodegraded while the organic matter during wet season was not biodegraded. Weather Dry Wet
Table 3 BOD/COD ratio for dry and wet season BOD/COD ratio Biodegradability Level 0.2 Biodegradable 0.05
Toxic zone
4. Conclusion Pelus River is considered as a rather clean river. This was supported by the slow development of the landuse in Pelus River. Since there were less anthropogenic activities in Pelus River, the good water quality was remained intact. However, with the construction of hydroelectric dam that might happen in the future, the water quality is expected to become lower than the present state. Water Quality Index analysis shows that, Pelus River status is slightly polluted (class III) during the dry season and polluted (class III) during the wet season. The pollution sources were transported during heavy rainfall through water surface runoff along different land use on the upstream. According to JRI, Pelus River status is considered as clean (class IIA). Since the surface runoff will wash away the pollutants and soil into the river during wet season, the water quality of Pelus River is expected to be lower during wet season. In the sediment loading analysis, the estimated sediment loading per year was 7.056 kg.ha/year. Sediment will be a major problem for the generation of electricity if the concentrations become too high. Sedimentation will make the river shallow and reduce the velocity of the water, thus making the production of electricity low. Thus, it is important to keep the level of sedimentation at an acceptable level. However, the present sediment load can be considered as low. Acknowledgements This study was supported by Ministry of Science, Technology and Innovation of Malaysia under Science Fund (No. 04-01-04-SF1784). Cordial appreciation goes to all staff from Faculty of Environmental Studies, Universiti Putra Malaysia (UPM), Malaysia.
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Hasrul Hazman Hasan et al. / Procedia Environmental Sciences 30 (2015) 133 – 138
References 1. Helland-Hansen, Holtedahl, E. T., & Liye, K. A.. Environmental Effects. Vol. 3. Hydropower Development. Norwegian Institute of Technology; 1995. 2. Thorne, C. R., Parker, C., & Simon, A.. The Effects of Variability in Bank Material Properties on Riverbank Stability: Goodwin Creek, Mississippi. Geomorphology 101; 2008; 533-543. 3. Amneera, W. A., Najib, N. W., Yusof, S. R., & Ragunathan, S.. Water Quality Index of Perlis River, Malaysia. International Journal of Civil & Environmental Engineering IJCEE-IJENS; 2013; Vol 13; 55-59. 4. Brezonik, P. L., & Stadelmann, T. H.. Analysis and Predictive Models of Stormwater Runoff Volumes, Loads, and Pollutant Concentrations From Watersheds In the Twin Cities Metropolitan Area, Minnesota, USA. Water Research; Vol 36 (7); 2002; 1743-1757. 5. Othman, F., & Eldin, M. E.. Assesement of the Klang River Quality Using the Water Quality Indices. Advance Materials Research; 2012; Vol 599; 101-150. 6. Webb, W. B., & Nobilis, F.. Long-term Changes in River Temperature and the Influence of Climatic and Hydrological Factors. Hydrological Sciences; 2007; 74-85. 7. Singh, T. A., Meetei, N. S., & Meitei, L. B.. Seasonal Variation of Some Physicochemical Characteristics of Three Major Rivers In Imphal, Manipur: A Comparative Evaluation. Current World Environment; 2013; Vol 8(1), 93-102. 8. Said, A., Stevens, K. D., & Shelke, G.. An Innovative Index For Evalauting WaterQuality In Streams. Environmental Management; 2004. 9. Meals, D. W., Richards, R. P., & Dressing, S. A.. Pollutant Load Estimation for Water Quality Monitoring Projects. Tech Notes 8. Tetra Tech, Inc; 2013.
ScienceDirect Procedia Environmental Sciences 30 (2015) 133 – 138
International Conference on Environmental Forensics 2015 (iENFORCE2015)
Water quality index and sediment loading analysis in Pelus River, Perak, Malaysia Hasrul Hazman Hasana, Nor Rohaizah Jamila*, Norfadilah Ainia a
Department of Environmental Science, Faculty of Environmental Studies, Universiti Putra Malaysia, 43400 UPM Serdang, Malaysia
Abstract River can be considered as one of the main water, food source and habitat for all life forms. It is important to keep the health of river at an acceptable level for optimum function to support living being. The water quality index is used to assess the water quality condition in the river. Water quality index (WQI) and JPS River Index (JRI) can be used to monitor the health of the river. In this study, a total of eight stations along the main river were used for sampling. Six selected parameters (biological oxygen demand, chemical oxygen demand, dissolved oxygen, pH, suspended solid, and ammoniacal nitrogen) were used to calculate the water quality index. Parameters used to calculate JRI are specific flow, total suspended solid, total dissolved solid, and turbidity. Since sedimentation is a major threat in Pelus River, suspended solid concentration is used to find the sediment load in Pelus River. From the analysis, mean WQI in dry season (71.73) is higher compared to mean WQI in wet season (59.90). This indicates that the water quality during wet season (Class III-polluted) is a bit lower than the water quality during dry season (Class IIISlightly polluted). The sediment load in Pelus River per year is estimated to be 7.056 kg.ha/year during dry season and it is expected to be higher during wet season. The anthropogenic activities such as deforestation and agriculture were expected to influence the stability of the water quality in Pelus River. © Published by Elsevier B.V This ©2015 2015The TheAuthors. Authors. Published by Elsevier B.V.is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of organizing committee of Environmental Forensics Research Centre, Faculty of Peer-review underStudies, responsibility of organizing committee of Environmental Forensics Research Centre, Faculty of Environmental Studies, Environmental Universiti Putra Malaysia. Universiti Putra Malaysia. Keywords: Pelus River; Water Quality Index (WQI); JPS River Index (JRI); sediment loading; seasonal
* Corresponding author. Tel.: 03-89468499; fax: 03-89466766. E-mail address: [email protected]
1878-0296 © 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of organizing committee of Environmental Forensics Research Centre, Faculty of Environmental Studies, Universiti Putra Malaysia. doi:10.1016/j.proenv.2015.10.024
134
Hasrul Hazman Hasan et al. / Procedia Environmental Sciences 30 (2015) 133 – 138
1. Introduction Pelus River is a cascading river; hence, the Tenaga Nasional Berhad (TNB) considered it as potential area to build a mini hydroelectric dam. Construction of hydroelectric dams can change the ecology of aquatic life, both at the upstream and downstream of the river and as well as give adverse effect in water quality [1]. Poor water quality may cause disturbance to the natural ecosystem, affecting the food chain, and can degrade population of aquatic life and wildlife [2]. Thus, it is crucial to keep the health of the river at an acceptable level. However, the actual condition of water quality in Pelus River need to be determined before any construction or development can be done. The essential of determining the health status of a river is by measuring the water quality of the river according to water quality index and JPS river index. The calculation of sediment loading is also important in estimating the amount of sediment in the future. There are many approaches that can be used to classify a river’s health. The most common analysis used are Water Quality Index (WQI) and Sediment Loading Analysis [3]. WQI is used in order to classify the river’s health status and sediment loading can be calculated by using the concentration of suspended solid [4]. Therefore, this study was carried out to fulfil two objectives: (i) To analyze the river quality status and classify the health of the river according to WQI and JPS River Index, (ii) To estimate the sediment loading of Pelus River, Perak. 2. Methodology 2.1 Study area The Pelus River catchment is a sub-catchment of the Upper Perak River, which flows from its source near the Thailand boarder, southwards through Perak State. The area has a humid tropical climate which is affected by the northeast and southwest monsoons, tropical winds that alternate during the course of the year. The humidity is about 80 % all year round and temperature range from 21 to 32 OC. The northeast monsoon blows from November to March, and the southwest monsoon from May to September. The periods between the monsoons are marked by heavy rainfall. The location of the study is taken along 22.11 km with 328.18 km2 of catchment area in Pelus River, Perak (Fig. 1). There were total of 8 stations cut across the downstream, middle stream, and as well as the upper stream. All these stations were served as the control stations to represent the actual condition of Pelus River. The samplings were conducted during two seasons; dry season (June 2014) and wet season (August 2014).
Fig. 1. Pelus River catchment Area and sampling stations
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Hasrul Hazman Hasan et al. / Procedia Environmental Sciences 30 (2015) 133 – 138
2.2 Sampling and Preservation Water samples were collected approximately 10 cm below the water surface using HDPE bottle. The samples were preserved by a few drops of nitric acid (to reduce pH until below 2) for COD and stored in an icebox and transported to laboratory for analysis within 48 hours. 2.3 Water Quality Index Analysis Water Quality Index method that is similar to Malaysia’s Water Quality Index method has been practiced in various countries. National Water Quality Standard (NWQS) is used as a tool for guidelines in maintaining Malaysia’s river water quality. The objective of NWQS is to create a benchmark of water quality for the protection and management of the surface water [5]. Six water quality parameters include dissolve oxygen (DO), Biological oxygen demand (BOD5), chemical oxygen demand (COD), suspended solid (SS), pH, and ammoniacal nitrogen (AN) were used to determine the Water Quality Index (WQI) for Pelus River. All of the parameters were multiply with their specific index: WQI=[0.22*SIDO]+[0.19*SIBOD5]+[0.16*SICOD]+[0.16*SISS]+[0.12*SIpH]+[0.15*SIAN]
(1)
The results from WQI were used to classify the water quality according to NWQS for Malaysia and the range for classes in WQI. 2.4 Sediment Loading Sediment loading can be calculated by multiplying the concentration of total suspended solid with the area of the watershed and the discharge from the watershed: Sediment Loading ሺ
୩Ǥ୦ୟ ୢୟ୷
ሻ= Concentration (mg/L)* Area (ha)* Discharge (m3/day)
(2)
2.5 JPS River Index (JRI) JRI can further classify the status of the river because the measurement of the river water flow and the catchment area of the river were taken into consideration in analyzing the JRI. Four sub-indexes include specific flow (SF), turbidity (Turb), total suspended solid (TSS), and total dissolve solid (TDS) were used for JRI calculation by using Sub- index of each parameters: JRI = 0.30*(SISF) + 0.13*(SITurb) + 0.35*(SITSS) + 0.22*(SITDS) Where, Specific flow, SF = flow (m3/s) / catchment area (km2)
(3)
3. Results and discussion 3.1 Water Quality Index (WQI) The status of water quality at sampling site was reflected on land activities within the catchment area. The calculated value of mean WQI for all sampling stations for each condition are shown (Table 1). Stations 1 2 3 4
WQI 73.93 72.7 71.98 74.58
Class III III III III
Table 1 River class and status Dry Status WQI Slightly polluted 88.60 Slightly polluted 54.57 Slightly polluted 57.24 Slightly polluted 54.06
Wet Class II III III III
Status Clean Polluted Polluted Polluted
136
Hasrul Hazman Hasan et al. / Procedia Environmental Sciences 30 (2015) 133 – 138 5 6 7 8 Mean WQI
68.95 70.94 67.15 73.64 71.73
III III III III III
Slightly polluted Slightly polluted Slightly polluted Slightly polluted Slightly polluted
41.76 59.76 62.15 61.09 59.9
IV III III III III
Polluted Polluted Slightly polluted Slightly polluted Polluted
Index Value
WQI In Wet And Dry Season Limit for Clean River Status (81-100)
100 90 80 70 60 50 40 30 20 10 0
Limit for Slightly Polluted River Status (60-80) Limit for Polluted River Status (0-59)
1
2
3
4
5
6
7
8
Sampling Station WQI Dry Season
WQI Wet Season
Fig. 2. Comparison of WQI in dry and wet season
The calculation of WQI showed the water class for all station during dry season and wet season falls within the class III except stations 1 and 5 in the wet season which falls within class II and class IV respectively (Table 1). The lowest water quality during dry season was in station 7 (67.15) while the lowest water quality during wet season was in station 5 (41.76). The mean WQI, it showed during dry and wet season was class III respectively. However, the status of the river during dry season was considered as slightly polluted while the status of the river during wet season was considered as polluted. The water quality during wet season was more polluted compared to dry season. The main reason is that the pollutants had been washed away into the river by surface runoff [6]. Moreover, the land use activities such as land clearing and forest fire, and soil erosion usually take place before the wet season, thereby increasing the pollutants load in to river by flash out during wet season. This indicates that seasonal variation will affect the water quality of Pelus River [7]. 3.2 JPS River Index, JRI Since the class of JRI can be extrapolated by using the time factor in the calculation of specific flow, the JRI was conducted only in dry season. Downstream sampling station (station 8) was selected in the calculation of JRI. This is because station 8 believed to represent the concentration of all parameters in JRI for the whole catchment area.
Hasrul Hazman Hasan et al. / Procedia Environmental Sciences 30 (2015) 133 – 138 Table 2. River class and status according to JRI Parameter Unit Value JRI 87.51 Specific Flow, Non-rainy day (SF) m3/s.km2 91.12 Turbidity, Non-rainy day NTU 103.48 TSS mg/L 70.62 TDS mg/L 100.04
Class IIA I V IIIB IIB
137
River status Good Clean Very poor Fair Good
3.3 Sediment loading analysis The concentration of total suspended solid in station 8 was used as pollutant because suspended solid is closely related with sedimentation. Since the estimation of sediment loading was done for the whole catchment area of the river, the concentration of suspended solid at downstream (station 8) was used because eventually all of the suspended solid will accumulate at downstream, thus it represent the suspended solid for the whole catchment area[8]. The sediment load that Pelus River produced during dry season was 7.056 kg.ha/year. 3.4 Biodegradability (BOD/COD ratio) The biodegradability of Pelus River can be calculated by using BOD/COD ratio. BOD/COD ratio is considered as a good indicator of the proportion of biochemically degradable organic matter to total organic matter because BOD is a biochemical parameter and it will reflect the biodegradability of organic matter in the water [9]. The BOD/COD ratio during dry season was 0.2 and the BOD/COD ratio during wet season was 0.05 (Table 3). This indicated that the organic matter during dry season was slowly biodegraded while the organic matter during wet season was not biodegraded. Weather Dry Wet
Table 3 BOD/COD ratio for dry and wet season BOD/COD ratio Biodegradability Level 0.2 Biodegradable 0.05
Toxic zone
4. Conclusion Pelus River is considered as a rather clean river. This was supported by the slow development of the landuse in Pelus River. Since there were less anthropogenic activities in Pelus River, the good water quality was remained intact. However, with the construction of hydroelectric dam that might happen in the future, the water quality is expected to become lower than the present state. Water Quality Index analysis shows that, Pelus River status is slightly polluted (class III) during the dry season and polluted (class III) during the wet season. The pollution sources were transported during heavy rainfall through water surface runoff along different land use on the upstream. According to JRI, Pelus River status is considered as clean (class IIA). Since the surface runoff will wash away the pollutants and soil into the river during wet season, the water quality of Pelus River is expected to be lower during wet season. In the sediment loading analysis, the estimated sediment loading per year was 7.056 kg.ha/year. Sediment will be a major problem for the generation of electricity if the concentrations become too high. Sedimentation will make the river shallow and reduce the velocity of the water, thus making the production of electricity low. Thus, it is important to keep the level of sedimentation at an acceptable level. However, the present sediment load can be considered as low. Acknowledgements This study was supported by Ministry of Science, Technology and Innovation of Malaysia under Science Fund (No. 04-01-04-SF1784). Cordial appreciation goes to all staff from Faculty of Environmental Studies, Universiti Putra Malaysia (UPM), Malaysia.
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Hasrul Hazman Hasan et al. / Procedia Environmental Sciences 30 (2015) 133 – 138
References 1. Helland-Hansen, Holtedahl, E. T., & Liye, K. A.. Environmental Effects. Vol. 3. Hydropower Development. Norwegian Institute of Technology; 1995. 2. Thorne, C. R., Parker, C., & Simon, A.. The Effects of Variability in Bank Material Properties on Riverbank Stability: Goodwin Creek, Mississippi. Geomorphology 101; 2008; 533-543. 3. Amneera, W. A., Najib, N. W., Yusof, S. R., & Ragunathan, S.. Water Quality Index of Perlis River, Malaysia. International Journal of Civil & Environmental Engineering IJCEE-IJENS; 2013; Vol 13; 55-59. 4. Brezonik, P. L., & Stadelmann, T. H.. Analysis and Predictive Models of Stormwater Runoff Volumes, Loads, and Pollutant Concentrations From Watersheds In the Twin Cities Metropolitan Area, Minnesota, USA. Water Research; Vol 36 (7); 2002; 1743-1757. 5. Othman, F., & Eldin, M. E.. Assesement of the Klang River Quality Using the Water Quality Indices. Advance Materials Research; 2012; Vol 599; 101-150. 6. Webb, W. B., & Nobilis, F.. Long-term Changes in River Temperature and the Influence of Climatic and Hydrological Factors. Hydrological Sciences; 2007; 74-85. 7. Singh, T. A., Meetei, N. S., & Meitei, L. B.. Seasonal Variation of Some Physicochemical Characteristics of Three Major Rivers In Imphal, Manipur: A Comparative Evaluation. Current World Environment; 2013; Vol 8(1), 93-102. 8. Said, A., Stevens, K. D., & Shelke, G.. An Innovative Index For Evalauting WaterQuality In Streams. Environmental Management; 2004. 9. Meals, D. W., Richards, R. P., & Dressing, S. A.. Pollutant Load Estimation for Water Quality Monitoring Projects. Tech Notes 8. Tetra Tech, Inc; 2013.