METAL GEOCHEMISTRY OF NERUS RIVER,TERENGGANU.

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1 METAL GEOCHEMISTRY OF NERUS RIVER,TERENGGANU. Poh Seng Chee 1*, Suhaimi Suratman 1, Chew Choon Keat 1, Noor Azhar Mohamed Shazili 2 and Norhayati Mohd Tahir 1. 1 Environmental Research Group (ERG)/ Department of Chemical Sciences, Faculty Science and Technology 2 Institute of Oceanography, University Malaysia Terengganu, Mengabang Telipot, Kuala Terengganu, Terengganu *Corresponded author: hayati@umt.edu.my Abstract The Nerus River passes through the Setiu and Kuala Terengganu districts, on the east coast of Peninsular Malaysia. It passes through the populated urban area of northeastern Kuala Terengganu and receives and carries different kinds of agricultural and urban solid and liquid wastes produces by agricultural based industries and domestic sewage. The objective of this study is to investigate trace metal concentration in suspended particulate and water of the Nerus River and relate this to the anthropogenic activities. Water samples were collected from nine sites during dry and pre monsoon seasons (from May to October). Water ph, temperature, electric conductivity and salinity were measured in-situ. The suspended particulate was separated from water by using 0.45 µm pore size acetate cellulose membrane filter. Water (filtered) samples were subjected to APDC-MIBK pre-concentration and particulate samples were totally digested by using strong acids. Cd, Cu, Zn and Pb were analyzed using GFAAS and ICP-OES. Although the overall concentration of the metals obtained were still within Class I limit of the INWQS, however the results indicated that there is an increasing trend of Cu and Zn concentration in Nerus River water compared to previous study done in High Cu and Zn concentration in suspended matter sampled at downstream station which received effluent from nearby factories. Keywords: urban river, dissolved metals, particulate metals Introduction The changes in quality and quantity of river water resources are accelerating due ever increasing humaninduced pollution and shift in land use. Population and economic growth continue to increase the demand on clean water; hence protecting high quality water resources has become local authorities foremost concern. It is well known that, river pollution is most commonly associated with the discharge of effluents from the sewers, drains or factories (Yuce et al., 2006). Apart from point sources, diffuse sources such a storm water and agricultural runoff and atmospheric fallout also significantly contributed to water pollution. Off the list of the river pollutants, heavy metals continue to be one of the most frequently occurring and toxic group of contamination. Their compounds are not subjected to destruction in the water body. Furthermore, the ability of some organism to accumulate heavy metals in their tissues would potentially lead to movement of these metals to higher tropic in the food chain (Chapman, 1997). The present study, carried out at the Nerus river basin, is aimed at compiling the spatial and temporal trends of heavy metals concentration in both dissolved and particulate forms in their river system. This work forms part of the long term water quality project for main river basins in Terengganu carried out by UMT researchers since Methods and Materials Sampling sites The Nerus River passes through the Setiu and Kuala Terengganu district, east coast of Peninsular Malaysia. The river basin extends about 77km and stretches between latitude 103º00 E to 103º06 E and longitude of 05º13 N to 05º23 N. Its catchments area totals 851 km 2. Its source is at Gunung Sarut and flows southeastern in towards the mouth of Nerus River which discharges its water into Terengganu River estuary before finally discharging into the South China Sea. Nerus River basin comprises of tributaries namely Tepuh River, Pelung River, Telemong River, Las River, Tong River, Linggi River, Tayur River, Temiang River and Semelang River (Shazili et al., 2004). The river flows through villages, farms and palm oil factories. It also passes through the populated urban area of northeastern Kuala Terengganu and receives and carries different kinds of agricultural and urban solid and liquid wastes produces by agricultural based industries and domestic sewage. 593

2 Poh Seng Chee et al: METAL GEOCHEMISTRY OF NERUS RIVER,TERENGGANU. Sampling procedure Water samples were collected in polyethylene bottles from nine stations along the waterway (Figure 1). All sampling bottles were cleaned using detergent followed by soaking in diluted nitric acid for one week and finally thoroughly rinsed with double deioned water. A total of 5 sampling trips were carried out at each sampling stations, between May to October ph, salinity and electrical conductivity were measured in-situ with YSI Multiparameter Hydrolab. During water sampling, the pre-cleaned sampling bottle was first rinsed with the river water before collecting the actual sample. Upon collection, samples were temporarily stored in an ice cooled container and transported back to the laboratory for further chemical analysis. Fig. 1: Location of sampling sites in Nerus River. Samples preparation and analysis Total suspended solid was analyzed by filtering a know volume of water through a pre-weighed 0.45 µm pore size Milipore filter paper and the resultant filter paper dried at 105ºC till constant weight (APHA, 1992). Samples were vacuum-filtered through 0.45 µm Millipore filter paper in a class 100 laminar flow hood. Both filter papers and filtrates were retained for particulate and dissolved metals analysis respectively. For particulate metals, the filtered suspended particulates were digested with a mixture of HNO 3 -HCl-HF acids (4:3:2 ml ratio) in a microwave digestion system (Ethos Plus, Milistone) at 210ºC for 30 min. Excess HF in samples were neutralized using 10 ml of saturated H 3 BO 3 (Hussain et al and Pruseth et al., 2005). For dissolved metals, the filtrate samples were preconcentrated and the matrix removed from water using APDC-MIBK solvent extraction method. A 200ml aliquot of the sample was placed in a 250ml teflon separatory funnel and the ph adjusted to with ammonia solution and nitric acid. Then, 5ml of 1% (w/v) APDC (ammonium pyrrolidine dithiocarbamate) was then added, shaken for 1 min and left to settle for 2 min. 594

3 Later, 6 ml of MIBK (methyl isobutylketone) was added, the separatory funnel shaken for 1 min and the aqueous and solvent layers left to separate for 2 min. The aqueous layer was then transferred to another separatory funnel and the extraction procedure repeated. The aqueous layer was discarded and the MIBK layers from the first and second extractions were then combined. Trace metals were back-extracted into 5ml 2M HNO 3 by shaking the acid with the MIBK for 30 s and the acid layer collected after 2 min of standing. This method provided a 40-fold preconcentration factor. Additionally, to check the accuracy efficiency of the extraction method, standard solutions with known concentrations were analyzed. In general, recoveries for Cd were 84.7 ± 0.87%, Cu ± 0.38%, Pb 82.6 ± 1.17% and Zn 80.3 ± 0.51%. Cd, Cu, Zn and Pb in the acid extracts were analyzed by inductively coupled plasma optical emission spectroscopy (Vista Pro, Varian).The Vista Pro features a custom designed charge coupled device (CCD) detector, which provided true simultaneous measurement and full wavelength coverage from 167 to 785 nm. The CCD detector contains continuous angled arrays that are matched exactly to the two-dimensional image from the echelle optics (Calderon, 2000). These features allowed both trace and major levels analytes to be measurement in the same measurement. The radio-frequency (RF) robustness of the instrument also permits the analysis of difficulty samples up to 5% total dissolved solids, using axially viewed plasma (Bridger and Knowles, 2000). The instrument also equipped with a concentric glass nebulizer and a glass cyclonic spray chamber and the entire system was controlled by ICP Expert software (Varian, Australia). The practical limit of detection for Cd, Cu, Pb and Zn were 0.5µgL -1, 0.06µgL -1, 0.6µgL -1 and 0.6µgL -1 representatively. Results and Discussion Table 1 presents the results obtained for dissolved and particulate metals analyzed in this study. Selected physical parameter measurements were also included in the table. Figure 2 and Figure 3 shows the spatial and temporal distribution of metals for the nine sampling stations respectively. The concentrations for dissolved fractions were in the range of µgl -1 Cd, µgl -1 Pb and µgl -1 Zn. The levels for particulate Cd, Pb, Cu and Zn varied from 0.23 to 0.97 µgl -1, 0.15 to1.85 µgl -1, 0.53 to 5.29 µgl -1 and 0.84 to 12.5 µgl -1 respectively. Generally, higher concentrations of Cd in particulate form compared to dissolved form were observed in Nerus River. Similarly for Cu, with exception of S1 and S6, particulate Cu is the dominant species in Nerus River. Zn on the other hand showed the reverse trend, where higher Zn concentration in the dissolved forms was found in all stations compared to the particulate form. In the case of Pb and Cu, no obvious trend could be seen between dissolved and particulate forms, some sampling sites like S1, S3 and S9 showed high contents of Pb in particulate forms whereas the remaining sites showed opposite trends. Table 1. Statistical results of ph, salinity, electric conductivity and metals concentrations in water of the Nerus River. Parameter Mean Median Std.Dev. Minimum Maximum ph Salinity EC (mv) TSS (mg/l) Dissolve form (µgl -1 ) Cd Pb Cu Zn Particulate form (µgkg -1 ) Cd Pb Cu Zn

4 Poh Seng Chee et al: METAL GEOCHEMISTRY OF NERUS RIVER,TERENGGANU. Assessment of metals concentration with sampling sites revealed that all metals with the exception of Pb showed a slowly increasing trend in going from S1 to S8 stations and then decrease again at S9. The gradual increased in concentration at downstream of the river is expected as more pollutants from upstream were introduced into the river system. Relatively higher levels of metals were determined at S7 and S8; these two sampling sites were near to the areas with more extensive development compared to other sites. Land use in the surrounding areas of S7 and S8 include sawmill, palm oil and rubber plantation and village settlements. The results thus indicated that anthropogenic sources may account for a sudden increased in metals content at both S7 and S8 relative to other stations. S8 in particular received additional loading of industrial wastes from Gong Badak industrial park via Lingai River. A sudden decrease at S9 could be due to water intrusion from Terengganu River. S9 is situated about a km upstream of the mouth of Nerus River before the river flows into Terengganu River and this station is also influenced by tidal movement. The water intrusion from Terengganu River could results in significant dilution at S Cd in ppb 1.4 Pn in ppb 0.7 Cd (Dissolved) Cd (Particulate) 1.2 Pb (Dissolved) Pb(Particulate) Cu in ppb 9 Zn in ppb Cu(Dissolved) Cu(Particulate) 8 Zn(Dissolved) Zn(Particulate) Fig. 2: Comparison studies between dissolved and particulate form of metals concentration for different stations. Apart from Cd, variations in dissolved and particulate form of all metals showed contrasting patterns at upstream and downstream stations of Nerus River. The pattern of Cd was relatively uniform along Nerus River system. The proportion of Cd in the particulate form was always greater at least 10 fold compared to dissolved form. In general, particulate Cu was found higher compared to dissolved form in all stations except at S1 and S6. Dissolved Zn on the contrary was the dominant species at all stations of Nerus Rivers with the exception of S2 and S5. Interestingly, dissolved Zn and particulate Cu illustrated similar pattern along Nerus River. Both species showed fluctuation pattern at upstream but exhibited a gentle increasing trend downstream. These relations can be related to the existing agricultural and industrial drainages around station S7, S8 and S9. For Pb, both dissolved and particulate form showed not much variation within sampling stations. The contrasting behavior of Pb might be related to historical Pb residues emitted from automobile exhaust that had accumulated in riverbed sediment. In this study, almost all water samples were collected from the road bridges. Particulate Pb in water 596

5 column could be contributed from both road dust on the bridges or re-suspension of riverbed sediment, whereas the dissolved Pb might be the result of re-dissolution of riverbed sediment or particulate Pb. 7 6 concentration (ppb) legend Cd(dissolved) Cd(Particulate) Pb(dissolved) Pb(Particulate) Cu(dissolved) Cu(Particulate) Zn(dissolved) Zn(Particulate) May June July September October Month Fig. 3: Temporal variations of metals concentrations for both particulate and dissolved forms in Nerus River It is noted that, the sampling period for the study fell within pre-monsoon (May to September) and north-east wet monsoon period (October to February). In general higher concentrations of all metals were observed during month of September and October (figure 3). During monsoon season, heavy rainfall has potentially increased the chances of terrestrial runoff. As reported by Göbel et al., (2007), storm water runoff from urban area is a major source of addition heavy metals to the river system. In additional, according to Lawson and Mason (2001), atmospheric suspended particle is washed out during raining episode, resulting in an increase in the concentration of certain trace metals into rivers. Figure 4 displays a 3D plot comparing the dissolved trace elements concentration in this study with 2001 study done by Shazili et al., (2004). In general, dissolved Cu and Zn concentration in this study has significantly increased at all stations within the 3 year periods. At downstream stations, dissolved Zn concentration in this study has increased at least doubled to tripled compared with the earlier study. As mentioned before, the possible contribution of dissolved Zn to rivers might come from Lingai River and it s tributaries that carry industrial and agricultural effluents surrounding the sampling station. On the contrary, Pb showed the opposite pattern. Where, the dissolved Pb in general showed a decreasing trend from 2001 to This observation could well be related to the phasing out of leaded gasoline since 1999 in resulting reduction of the Pb input to the environment. In the case of Cd, student T-test results (t-value= 4.93, p<0.05) showed that the differences in concentration of dissolved Cd for current and previous studies was not significant statistically. 597

6 Poh Seng Chee et al: METAL GEOCHEMISTRY OF NERUS RIVER,TERENGGANU. Conclusion According to Malaysian Interim National Water Quality Standards (INWQS), the levels of dissolved heavy metals in Nerus River are still within class I (natural level). However, results clearly illustrated that concentration of dissolved Cu and Zn showed an increasing trend within year of monitoring from 2001 to The present status of heavy metal geochemistry in Nerus River is still considered unpolluted, however, results in this study clearly showed that urbanization and human activities around Nerus River has resulted in an increasing trend of heavy metals monitored in going from upstream to downstream stations, particularly at stations that received waste discharges from nearby industrial and urban areas. Fig. 4: A 3D plots illustrated a comparison study of dissolved metals within stations in Nerus River. Acknowledgement The authors would like to thank the Department of Chemical Sciences, UMT and the Ministry of Higher Education (FRGS grant vot number 59066) for the financing this study (CCR) and supporting (PSC) in attending the 12 th Asian Chemical Congress. References 1. Yuce G., Pinarbasi A., Ozcelik S. and Ugurluoglu D Soil and water pollution derived from anthropogenic activities in the Porsuk River Basin, Turkey. Environ. Geol. 49,pp Chapman, P.M., Is bioaccumulation useful for predicting impacts. Mar. Pollut. Bull. 34, pp APHA, American Public Health Association, Standard methods for the examination of water and wastewater, 18 th Edition. Edited by Greenberg A.E., Lenore S. C., and Andrew D.E. American Public Health Association, American Water Works Association, and Water Environment Federation. 4. Husain L., Yang K.X., Swami K Determination of trace metals in atmospheric aerosols with a heavy matrix of cellulose by microwave digestion-inductively coupled plasma mass spectroscopy. Journal of Spectrochimica Acta Part B: Atomic Spectroscopy 57,pp Pruseth K.L., Yadav S., Mehta P., Pandey D. and Tripathi J.K Problem in microwave digestion of high-si and high-al rocks. Journal of Current Science 89:

7 6. Calderon V Rapid measurement of major, minor and trace levels in soils using the Varian 730-ES. Varian ICP-OES application note. 7. Bridger S. and Knowles M A complete method for environmental samples by simultaneous axially viewed ICP-AES following USEPA guidelines. Varian ICP-AES at work. Accessed on 1 November Göbel P., Dierkes C. and Coldewey W.G Storm water runoff concentration matrix for urban areas. Journal of Contaminant Hydrology 91,pp Lawson N.M. and Mason R.P Concentration of Mercury, Methylmercury, Cadmium, Lead, Arsenic, and Selenium in the Rain and Stream Water of Two Contrasting Watersheds in Western Maryland. Water Research 35,pp Shazili N.A.M., Sharipudin H., M.Tahir. N. and Yunus K Dissolved Cd, Cu, Pb and Zn concentration in sungai Nerus, Terengganu. Malaysian Journal of Analytical Sciences 8,pp