RIVER CLASSIFICATION BASED ON THE PHYSICO- CHEMICAL PROPERTIES IN THE PETANI RIVER BASIN

Transcription

1 RIVER CLASSIFICATION BASED ON THE PHYSICO- CHEMICAL PROPERTIES IN THE PETANI RIVER BASIN HAZZEMAN HARIS*, WAN MAZNAH W. O AND MASHHOR MANSOR School of Biology, Universiti Sains Malaysia, 118 Pulau Pinang, Malaysia. *ha33eman@yahoo.co.uk ABSTRACT Water samples collected from 6 sites along the Petani River Basin were analyzed for alkalinity, dissolved oxygen, biological oxygen demand, chemical oxygen demand, nitrite, nitrate, ammonia, orthophosphate, total dissolved solids (TDS) and total suspended solids (TSS). River classification was made possible by calculating the Water Quality Index (WQI) where 1 represent the highest water quality. The highest mean WQI was recorded at Petani River- (54.35) while the lowest mean was recorded at Petani River- (47.59). Generally the sampling stations that were located in the centre of the Sungai Petani town showed lower WQI value compared to the other sampling stations which were located near the Petani River source and near the confluence of the Merbok River. River recorded a higher concentration of nitrite and nitrate compared to other sites while Sungai has the highest alkalinity and TDS value throughout the whole sampling period. Sungai also showed the lowest ammonia concentration. The one-way ANOVA analysis conducted showed no significant differences in the amount of TSS and orthophosphate between all of the sites and sampling interval. Keywords: Water Quality Index; physico-chemical properties; nutrients INTRODUCTION Malaysia has an annual rainfall of 3 mm or 99 billion m 3 of which 566 billion m 3 appears as surface run-off, 64 billion m 3 becomes groundwater recharge and 36 billion m 3 return to the atmosphere through evapo-transpiration [1]. Being the nation with the highest water consumption, freshwater resources such as streams and rivers are of paramount importance to the development of the country since they contributed up to 98% of the total water used in Malaysia and the rest are from groundwater [2]. As the nation develops and increases in population, a serious water crisis such as pollution due to poor planning can cause environmental degradation and a decline in beneficial use of river [3]. Therefore regardless of the abundance of water, there is a shortage of clean water for human consumption of the population [3]. The major aim of this study was to evaluate the river surface water using the Water Quality Index and the classification used by the Malaysian Department of Environment (DOE). Other physico-chemical analyses were also done to determine the level of pollution in the river. Petani River Basin. Petani River is the main river that flows through the centre of the town of Sungai Petani. The commercial centre for the town is situated on both sides of the riverbanks between 45 m to 6 m from the confluence. The total length of Petani River is 12.5 km with a 35 ha of catchments area (including the catchments areas of its tributaries). Petani River is tidal in nature from the confluence until more than 6 km upstream

2 [4]. Industrial, commercial and residential areas are the main types of land use in the catchment areas of Petani River. The River, River and River are the main tributaries of the Petani River system. MATERIALS AND METHODS Water samples ware collected monthly from September 25 to February 26 using a home made water sampler and kept in polyethylene bottle which were later preserved at 4ºC. All the water quality analysis which comprised of nitrite, nitrate, ammonia, orthophosphate, alkalinity, biological oxygen demand (BOD), chemical oxygen demand (COD) and total suspended solids (TSS) were carried out according to APHA [5]. Total dissolved solids (TDS), conductivity, salinity and temperature were measured in-situ using sension5 conductivity meter. Dissolved oxygen (DO) was measured using YSI Model 57 oxygen meter while the ph value was determined using a CyberScan 5 ph meter. Water Quality Index (WQI) was calculated using the mean values of DO, BOD, COD, ph, ammonia-n (AN) and TSS. The values were converted to sub indices (SIs) using the best-fit equation and aggregated to compute the WQI according to the following equation [6]: WQI =.22 SI DO +.19 SI BOD +.16 SI COD +.15 SI AN +.16 SI SS +.12 SI ph, where SI is the sub index of each parameter. The descriptions of the water quality status related to the WQI are stated in Table 1 which is according to the values referred by the Malaysian Department of Environment [7]. Table 2 explains the type of uses associated with each class of water quality. Table 1: Water Quality Index Used by the DOE [7] Parameter Class Unit I II III IV V Ammoniacal mg/l < > 2.7 Nitrogen BOD mg/l < > 12 COD mg/l < > 1 DO mg/l > < 1 ph mg/l > < 5. > 5. Total Suspend mg/l < > 3 Solids Water Quality Index > < 31. Table 2: The Classification of Water Quality and Their Uses. Class I II A II B III IV Uses Conservation of natural environment water supply I- practically no treatment necessary. Water supply II conventional treatment required Recreational use with body contact Water supply III extensive treatment required Irrigation

3 RESULTS AND DISCUSSION The water classification for each sampling station is shown in Table 3. The lowest Water quality index (WQI) obtained was recorded at Petani River-, which means that it is the most polluted site and falls in Class 4 according to the river classification system by the DOE. The highest WQI was recorded at Petani River- with a value of and falls in Class 3. The water at Petani River- has the best water quality compared to the rest (Table 3). Table 3: Water Quality Index Values for Each Sampling Stations along Sungai Petani River Basin. Stations Water Quality Index Class The low WQI recorded in Petani River- may be due to the accumulation of waste from the upstream. This is in agreement with the report by the DOE [7] that the rivers in Malaysia were slightly polluted or polluted at the downstream [8]. The finding from this study is also similar to the findings made by Arienzo et al., [9]. The study conducted focused on the impact of land use and urban runoff on the contamination of the Sarno river basin in southern Italy and their results had indicated degradation in the river water quality especially near the river mouth. This can be attributed to several man induced activities such as urban runoff to surface river water due to direct or unregulated discharges in the Petani River or its tributaries. While the slightly better WQI recorded in Petani River- can be caused by the dilution of nutrients by the seawater from the confluence where Petani River joins the Merbok River. Generally the DO, BOD and ammonia level recorded at all sites falls into class 4 except Petani River- that was in class 3. The COD level in River, River, River and River were in class 4 while Petani River- and Petani River- were in class 5. The amount of TSS in River, River and River were in class 1, while River and Petani River- falls in class 2. Petani River- has the highest amount of TSS and falls into class 3. The ph level at all site were in class 2. The amount of nitrate in River and Petani River- was significantly different from the amount recorded in River (p<.5). The mean nitrate for River and Petani River- was.2 ±.2 mg/l and.17 ±.12 mg/l respectively, while the mean value obtain at River was 1.6 ± 1.42 mg/l. The highest concentration of nitrate was recorded in December at River (4.26 mg/l) while the lowest was also recorded in December at River (.4 mg/l) (Figure 1). There were significant differences in the concentration of nitrite between sites (p<.5). The Tukey HSD test showed that there were 2 homogenous subsets where the first group consisted of River, River and Petani River- while the second group was made up of the River. This means that there were significant differences between the sites that incorporate each group. The mean concentration of nitrite at River was.2 ±.2 mg/l,.6 ±.2 mg/l at River and.6 ±

4 .4 mg/l at Petani River-. The highest concentration was recorded at River (.77 mg/l) in September and the lowest concentration was recorded at River (.1 mg/l) also in September (Figure 2). The higher concentrations of nitrite and nitrate at each site in December compared to the other months can be explained by the higher rainfall reported by the Malaysian Meteorological Service for that particular month which was around 3 mm. The higher rainfall will increase urban runoff and surface runoff especially from the industrial and residential areas located at the Industrial Area, which will increased the amount of nitrite and nitrate in the Petani River and its tributaries. Nitric acid that was carried in rainfall as a result of high energy fixation between atmospheric nitrogen and oxygen can also contribute to the higher concentration of nitrite and nitrate in the river since high-energy fixation accounts for almost 1 Tg (or Teragram, where 1 Tg is the equivalent of 1 million metric tons) of nitrate entering the nitrogen cycle [1]. The highest concentration of orthophosphate was recorded at River (.864 mg/l) in October and the lowest concentration was recorded at Petani River- (.18 mg/l) (Figure 7) in February. Orthophosphate concentration was generally stable during the sampling period except for a few occasions where the reading fluctuated at the River, River and the River. The high concentration recorded at River can be due to runoff from agriculture sites. The area along River was being developed during the sampling period and the clearance of land in this area has made it more susceptible to soil erosion. The trees and shrubs cleared from this land were dumped near the river and this contributed to the enrichment of orthophosphate when it decomposed. Meanwhile the high orthophosphate concentration recorded at River (January) and River (October and February) can be due to untreated domestic sewage that contains high amount of phosphorus from detergent, toothpaste and etc. The clearing activities along the riverbanks of Petani River and its tributaries increased leaching of chemical and soluble that pollutes the river. This situation is similar to the findings made by Abdul Rahim and Zulkifli [11] which reported the removal of forest cover especially the undergrowth and litter layer induced erosion and enhanced leaching of chemical and other solutes. The additional source of organic matters in the form of shrubs and trees that had been cut down to clear the land, coupled with greater sunlight exposure enhanced microbiological activities leading to higher rates of decomposition, mineralization and nitrification [11]. The mean alkalinity in River (48.6 ± 24.5 mg/l) and River (55.23 ± 9. mg/l) was significantly different from the mean alkalinity of Petani River-jetty (9.49 ± 16.73mg/L) (ANOVA, p<.5). Comparison made between sampling intervals showed that the mean in December (47.5 ± 1.78 mg/l) was significantly different from the value recorded in September (81.32 ± mg/l) (ANOVA, p<.5). The highest alkalinity was recorded in September at Petani River- (18.7 mg/l) and the lowest was recorded at River (19.26 mg/l) in October (Figure 3). Alkalinity in December was also low. This phenomenon can also be attributed to the higher rainfall in that particular month. Rain water will dilute the bicarbonate in the river water and thus reduced its ability to resist the changes in ph [12]. Significant difference was found in the concentration of ammonia between the sampling months (Figure 4) (ANOVA, p<.5). The concentration of ammonia in February (.7 ±.4 mg/l) was significantly different from the value recorded in October (1.47 ±.61 mg/l), January (1.61 ± 1.2 mg/l), November (2.3 ±.63 mg/l) and December (2.18 ±.91 mg/l). The highest concentration was recorded at River (3.49 mg/l) in January, while the lowest concentration was recorded in Petani River- (.1 mg/l) in February. The high concentration of ammonia at River can be caused by the usage

5 of urea fertilizer by the local residents on their farms. Since these farms were located near the river, surface runoff washed the urea into the river. The low rainfall in January increased the concentration of ammonia in River. Since it is a small flowing water body, the nature of this river makes it more vulnerable to weather changes compared to other sampling stations. With no rain to dilute the water and low concentration of DO, the water inhibits the aerobic bacteria from processing the organic compound into something less dangerous, stable and less smelly such as nitrite and nitrate [13]. Three homogenous subsets existed when the amount of TDS was compared between sites. This shows that there is a significant difference between the three subset groups. The first group consisted of River (74.67 mg/l), River (95.5 mg/l), River ( mg/l) and River (3191.). The second group consisted of River, River and Petani River- ( mg/l) while the third group consisted of Petani River- ( mg/l) and Petani River- station. The highest TDS recorded was 17 mg/l at Petani River- while lowest TDS was 9 mg/l were recorded in both River and River (Figure 5). The sudden increase in TDS at almost every site in January can be attributed to the low monthly rainfall recorded in that particular month. The rainfall was below 5 mm in the northern area of peninsular Malaysia (source: Malaysian Meteorological Service). The low rainfall is suspected to increase the concentration of dissolved solids in the river water hence increasing the TDS value. The highest amount of TSS was recorded at Petani River- in January (17 mg/l) and the lowest TSS was recorded in February at River (4 mg/l) (Figure 6). The high TSS recorded in January at Petani River- and Petani River- station may be due to the boating activity in this part of the river. Since the sampling was done during high tide, boating activity by the local fisherman was high. As the boats move along the river, the waves created by these boats eroded the riverbank especially in areas that were not covered with mangrove forest. The high tide also might bring in suspended solids from the Merbok River. It can be concluded that the cause of pollution in Petani River were due to the anthropogenic sources from industries and urbanisation along the river bank. Nitrate Nitrate (NO3-N) mg/l Figure 1: The Concentration of Nitrate from September 25 to February 26 at All Sites.

6 Nitrite (NO2-N) mg/l Nitrite Figure 2: The Concentration of Nitrite at Each Site from September 25 to February 26. Alkalinity Alkalinity (HCO3) mg/l Figure 3: The Alkalinity at Each Site from September 25 to February 26.

7 Ammonia Ammonia (NH3-N) mg/l Figure 4: The Concentration of Ammonia at Each Site from September 25 to February 26. Total Dissolved Solids mg/l Total Dissolved Solids (TDS) Figure 5: Amount of TDS at Every Sampling Site from September 25 to February 26.

8 Suspended Solids (TSS) Suspend solids mg/l Figure 6: Amount of TSS at Every Sampling Site from September 25 to February 26. Ortho-Phosphate Ortho-phosphate (PO4-P) mg/l Figure 7: The Concentration of Orthophosphate at Each Site from September 25 to February 26.

9 REFERENCES [1] Azhar, M. G., Managing Malaysian Water Resources Development, Buletin Kesihatan Masyarakat Isu Khas, 2, pp [2] Abdullah, H. K. and J. Jusoh, An Appraisal of Malaysia s Water Resources: Problems and Prospects, State of the Environment in Malaysia, Consumers Association Penang [3] Madsen, L., M.E. Hansen, M.R. Gjerding, S. Pedersen. Implementation of a Water Vision- In The Case Of the Langat River, Malaysia. Universiti Kebangsaan Malaysia and Department of Environment, Technology and Social Studies Roskilde University Centre Denmark. 22. [4] Perunding Bakti Sdn. Bhd. Kajian Pelan Induk Saliran Bandar Dan Reka Bentuk Terpeinci Sungai Petani, Kedah Darul Aman: Executive Summary & Final Report (Volume I). Jabatan Pengairan dan Saliran Sungai Petani [5] APHA (American Public Health Association), Standard Methods for the Examination of Water and Wastewater. 18th edn [6] Wan Maznah, W. O. & M. Mashor, Aquatic Pollution Assessment Based on Attached Diatom Communities in the Pinang River Basin, Malaysia. Hydrobiologia 487: [7] DOE (Department of Environment Malaysia). Malaysia Environmental Quality Report 2. Department of Environment, Ministry of Science, Technology and Environment Malaysia. Maskha Sdn. Bhd. Kuala Lumpur, 86pp. 21. [8] Azrina M.Z., C.K. Yap, A. Rahim Ismail, A. Ismail, S.G. Tan, Anthropogenic Impacts on the Distribution and Biodiversity of Benthic Macroinvertebrates and Water Quality of the Langat River, Peninsular Malaysia. Ecotoxicology and Environmental Safety. 25. [9] Arienzo, M., P. Adamo, M.R. Bianco, P. Violante, Impact of Land Use and Urban Runoff on the Contamination of the Sarno River Basin in Southern Italy. Water Soil Pollut. 131, 21, [1] Vitousek. P. M, Chair, J. Aber, R.W. Howarth, G.E. Likens, P.A. Matson, D.W. Schindler, W.H. Schlesinger & D.G. Tilman, Human Alteration of the Global Nitrogen Cycle- Caused and Consequences. Issues in Ecology. No 1. Ecological Society of America [11] Abdul Rahim, N. and Y. Zulkifli, Hydrological Impact of Forestry and Land-Use Activities: Malaysian and Regional Experience. Water: Forestry and land use perspectives. Kuala Lumpur, Malaysia [12] Zarul Hazrin Hashim, Fish Assemblages in Disturbed Low-Order Headwater Streams in Temenggor Reservoir, Perak. Universiti Sains Malaysia. Unpublished MSc thesis. 26. [13] Wan Maznah W.O., Penggunaan Alga Perifiton di dalam Penilaian Status Kualiti Lembangan Sungai Pinang. Universiti Sains Malaysia. Unpublished PhD thesis. 22.