Wednesday, June 5, 2019

Effect Of Heavy Metals On The Environment Environmental Sciences Essay

Effect Of Heavy Metals On The Env press outment Environmental Sciences EssayHeavy coats ar most abundant forms of pollution in Malaysia either in the forms of solid or liquid. With the vast industrial enterprise and economic development in coastal region, strained coats are continuing to be introduced to the estuarine and coastal environment which eventually devastation up into the river, runoffs and land based area (Yu et al., 2007). Metals diffuses into the aquatic environment pull up stakes settle down and be incorporated into sediments together with organic matters, Fe/Mn oxides, sulfides, and clay (Wang and Chen, 2000). However, baleful metal mobility or availability in begrime materials depends to large extent upon the different chemical and mineralogical forms that occurred (Song et al., 1999). Therefore, sediments seem to be an excellent medium in the assessment of the metals bound to the particulates. N unrivaledtheless, sediments are known to act as a sink for sl ow metals to be introduced into pees either from both natural and anthropogenic showtimes thus providing an excellent proof of mans impact (Pempkowiase et al., 1999 Guevara et al., 2005). In addition, they may withal act as traps for various types of pollutants including heavy metals (Poh and Mun, 1994). Indeed, changes in environmental conditions such as pH and redox potential should be monitored since it may results in remobilization of heavy metals. Unfortunately, due to the scarcity of information available to establish the heavy metal concentration in sediment utilise sequential origination, no data is presented concerning the heavy metal pollution in the rivers except for one author Shazili et al., 2008 on Langat River Basin. Heavy metals element is particularly crucial because any slight changes in availability may cause these elements to become either toxic or deficient to plant (Krishnamurti et al., 1995). In fact, sequential extraction analysis is a technique whi ch is used to investigate the geochemical partitioning of heavy metals amongst solid mineral and organic phases in sediment or other earth minerals (Howard and Vandenbrink, 1999). serial fractionation besides frequently used in approaches to evaluate metals distribution into different chemical forms present in solid phases. Although direct systems provide an unambiguous identification of the heavy metal forms and ways why they occur, they might non be sufficiently sensitive where heavy metals occur at relatively low levels and they do non provide quantitative information on heavy metal mobility and availability (Song et al., 1999). However, sequential extraction approach is undoubtedly useful since few attempts have immaculate and few modification have been make based on Tessier et al., (1979) such as Silviera et al., (2006) Krishnamurti et al., (1995) Song et al., (1999) Forghani et al., (2009), Poh and Mun, (1994).2.0 Problem StatementLangat river, Bernam River and Klang Riv er basin is located in the tell apart of Selangor in which known to be the most developing states in Malaysia other than Kuala Lumpur. All of these rivers are primarily strategic as water supply antecedent not only limited to supplying water to consumer but also for other purposes such as aquaculture and agriculture activity, fishing, effluent discharge, irrigation and even sand mining. With the vast industrialization held in the river such as sand mining it generate the release of metal bound in sediment into the water promoting metals diffussion into the aquatic organisms and eventually ends up into humans body. Moreover, from each one metals poses their own threat to human, particularly Cadmium (Cd) are known for causing adverse health effects, once ingest into our body it testament cause lung cancer moreover it seldom classic as a cause of phytotoxicity in paddy field (Chaney, 2010). On the other hand, Zinc (Zn) is a deficient and phytotoxic element in sediment which caus es abdominal pain to humans, the latter due to industrial contamination (Chaney, 2010). Copper (Cu) in sediments strongly adsorbs to clay minerals, iron and manganese oxides and organic material. In addition, it tends to remain in horizons that have a greater organic content whereas sandy sediment with low pH poses the superlative potential for Cu leaching. On contrary, lead (Pb) is considered to be one of the major environmental pollutants and has been incriminated as a cause of accidental poisoning in national animals more than any other substance. In a nutshell, these metals are emboldened to be analyses since this metal endured high up toxicity in the environment thus poses high potential threat and risk to humans and living organisms.3.0 Significance of StudyThis topic is prominent since in Malaysia there is only few attempted moot using sequential extraction as medium in determining the fate of metals in environment. Particularly, this study leave behind be useful as a b aseline data for goverment bodies to be more sensitive on the issues related to heavy metals. On the other hand, this study allow for provide a motion picture on the sources of metals which contribute the most anthropogenically or naturally to the environment since the major contributor on the environment deteroriation is a non point source. Therefore, identifying the potential sources is crucial in maintaining the environment. Nonetheless, by conducting this study it ables to generate a profound understanding on the sources and parent materials of which heavy metals are highly introduce to the estuary. Thus, contribute to the discovery of metals aptitude and percentage of binding to organic or inorganic pollutants. Hence, providing an illustration on the status of pollution in the selected rivers based on screening of the forms of metals associated in the river. In addition, the attempted method will utter a method development in assesing the metal in the environment. This study is beneficiary especially by the segment of Irrigation on the overview of the river status thus able to mitigate a scheme on reducing the metal accretion into the river by identifying the source of pollution.4.0 explore intentionTo ascertain the chemical and mineralogical forms of Pb, Cu, Cd and Zn in selected polluted river.To profile the metal speciation (Pb, Cd, Cu, Zn) in the sediment at selected polluted river in Selangor.To determine the heavy metals affinity for specific geochemical phases in the recently deposited sediments in the river.To identify the pollution sources and active component of heavy metals accumulate into the surficial sediment and its chemical port in the aquatic environment.5.0 Literature ReviewA river is component of water cycle. Mostly rainfall on land will passes by dint of a river on its way to the ocean and smaller side streams will joins the river forming a tributaries (DID, 2010). In Malaysia, the water within a river generally originates from precipitation through surface runoff, groundwater load (as seen at base flow conditions / during periods of lack of precipitation) and release of stored water in natural or man-made reservoirs, such as wetlands, ponds or lakes (DID, 2010). Therefore, the rainfall will generate the surface runoff and flows into the river. While the runoff will collect all the suspended particulates on the land surface into the river. This is why source of metal is very hard to trace since it is a non point sources elements which diffuse into the river Basin. Therefore, in this case sediments play an heavy role in identication of the metals since it acts as transport and store of potentially hazardous metals (Yu et al., 2008).Bernam River is approximately about 3335 km2 and it forms a boundary between States of Perak in the north and Selangor in the south. The undulating hills of Bernam River merge into an undeveloped peat swamp area where the downriver of the peat swamp is a obtusely populated c oastal strip along the Bernam River. Rice is courtly in the lower areas ad- jacent to peat swamps and rubber, oil palm, coconuts and cocoa are cultivated in estates and smallholder schemes. Agrochemicals (fertilizers and herbicides) used on agricultural lands suggest a potential non-point source of pollution and toxicity affecting the aquatic ecosystems (Yap and Ong, 1990). Logging generates pollution through soil erosion, siltation and sedimentation in the streams. On the other hand, Langat River basin covered an area of 1300 km2 in the south of Kuala Lumpur and the length of Langat River is approximately about 120 km long (Sarmani, 1989). Langat river known as an important water source not only limited to supplying water to consumer but also for other purposes such as recreation, fishing, effluent discharge, irrigation and even sand mining (Juahir, 2009). Whereas, Klang River is notable as a highly polluted river in Selangor which flows through Kuala Lumpur and suburban area of t he densely populated and highly industrialized Klang Valley (Tan, 1995). The upper reaches of the Klang River serve as an important source of water supply to an estimated population of two million population in this region, together with its growing industrial activities (Tan, 1995). According to the Environmental Quality Report (Department of Environment, 2007), the Klang River is regarded as one of the rivers which have been seriously affected by pollution. Discharges of sewer water from industrial activities in the Klang River basin have also contributed to increasing levels of organic chemical pollutants in the waterways.However, metals in sediment comes in various forms of elements. Therefore, each metals may give beneficiary and may also cause a potential threat to human. Once consumable in our body it might cause a significant imbalance thus causing deformities and poor health (Birungi et al., 2008). Sediment are an important features in the river any activities occured rel ated to sediment such shift or mining may cause the release of heavy metals into the river. This is because heavy metals may enter into natural water and become a part of the water sediment system and their distribution processes are controlled by a dynamic set of physical-chemical interactions and equilibrium (Jain, 2003). Therefore, the metals may bind to the aquatic organisms. Since these river is an inborn water source in the state of Selangor, any aquaculture activity held in the river may have a significant potential of heavy metals accumulate into the fish or prawns. On the other hand, the deposition of metals in sediments usually occurs through an interaction between sediment and water (Piron et al., 1990), whereby changes of metal contents of sediments and water depend on changes of water chemistry, such as, temperature, pH and solute concentration. That is why such study is prominent since metals interactions between bed sediment and water in aquatic environment play an important role on water quality and the fate and transport of metals.There are series of modification of sequential extraction technique have been made upon the suitability of the study. The recent modification are introduce by Silviera et al., 2006 which proposed to the studies specifically on the tropical soil. This method listed out seven fractionation steps which each illustrates the metal bound particulate in the sediments. The first three fractionation steps explains the geochemical condition of the sediment whereas the fourth to the seventh steps refers to the anthropogenic conditions. This method is an alternative way to determine the source of metals, because the anthropogenically sourced metals preferentially partition to the non-residual phase of the sediment while the residual phase generally reflects background geochemical conditions (Forghani et al., 2009). Moreover, this method were elect since it selectively extracts metal bound by specific sediment fractions with mi nimal effect on the other sediment components (Silviera et al., 2006). In addition, this method are an important tool for predicting the potential effects of environmental changes and land application of metals on the redistribution of chemical forms in tropical sediments (Silviera et al., 2006).6.0 Research MethodologySediment Sampling xxx representative surficial sediments (0-20cm depth) will be taken from selected polluted river in Selangor from upstream to downstream of the river. Surface sediments samples will be collected in triplicates and homogenized in a zip lock polyethylene bags. The sampling will be conducted during low tide to enable the source of pollution from the mainland to be find out without the influence of input from seawater compared to sampling during high tide. Sediment samples will be collected using plastic scoops, Eckman Grab or core taste-tester and place into acid-washed double zip-lock polyethylene bag. All samples will be stored in cool box at 4C du ring transportation to the laboratory precedent to analysis.Sampling preparationThe laboratory apparatus are also acid washed and rinsed thoroughly first with distilled water to ensure any contaminants and traces of clean and jerking reagent were outside before the analysis. Pre-clean polycarbonate spin tube with soaked overnight in 5 % (v/v) nitric acid rinsed with distilled water after 24 hours prior to analysis. It is performed in clean laboratory to minimize the potential risk of contamination.Laboratory AnalysisPhysicochemical parameters such as pH, redox potential, salinity and conductivity will be measured using the 12 ratio of sediment and double deionized water (DDW). In addition, cations exchange capacity (CEC) and loss on ignition (LOI) will also be determined in the study.Physicochemical ParametersThe sediment physicochemical analyses will be determined by mixing 10 g of air change sample (Cation Exchange Capacity (CEC)Sediment samples for CEC object will be prepar e in two 10 g portions, one for treatment with a 1 M NaCl solution and other with a 1 M NH4Cl solution. Approximately about 10 ml of 95% ethanol will be carefully poured on sediment sample and drawn through the sediment by suction. The ethanol remaining in the sediment will later be removed by overnight evaporation. Then, the sediment will be transferred to small 50 ml Polycarbonate centrifuge tubes. Hence, about 30 ml of 1M NaCl was applied to one set of sub samples and 1 M NH4Cl solution was added to other set. The centrifuge tubes contains with the sediment pre-treated with NaCl and NH4Cl therefore will be shaken end over end for about 10-20 minutes and subsequently centrifuged at 3000 rpm for 30 minutes in order to settle the fines. After the samples are centrifuged, the supernatant will be removed with syringe and filter through a 0.45 m filter. About 15 ml of sample will be used for the analysis of Ca, Mg, and K from the NaCl supernatant solution and preserved with 1% 7M HNO3 . Meanwhile, the solution from NH4Cl supernatant will be used for determination of Na and also preserved with 1% 7M HNO3. test analysis for Ca, Mg, Na and K adopted similar procedure as in the case of major cations determination.The exchangeable cation concentration are converted from milliequivalent/100g to equivalent fractions (T) as (Apello Postma, 2005)T = meqI-Xz_____I, J.. meqI-XzWhere I, J,. are exchangeable cations, meqI-Xi is normally given in meq/100 g dry sediment and meqI-Xz is essential equal to CEC, ignoring minor amounts of Fe, Mn, etc.Loss of Ignition (LOI)Dry a sample in an oven at 105C to constant consultt. Accurately weigh 1g of this dried sample and pour into a preweighed dry crucible. Optionally, a few drops of H2O2 may be added at this stage to promote oxidation. The samples will be transfered into gag furnace and gradually accession the temperature to 500C. Leave inside the oven at this temperature for at least 4h or overnight if convenient. Cool, trans fer to a dessicator and allow it to cool to manner temperature. Weigh and calculate loss on ignition in % asLOI (%) = 100 x (M1 M2)M1Where M1 is the initial weight (g) and M2 is the weight after ignition (g).Sequential Extraction ProcedureThe methods that will be used in this study are based on modification methods from (Silviera et al., 2006). The fractionation of heavy metals in sediments will be carried out in triplicate, using 1 g of air-dried sediment. Then, sediment samples will be placed in 50 ml polycarbonate centrifuge tubes, mixed in a stepwise fashion with various reagents as shown in figure 1, and the suspensions equilibrated. By following equilibration, the solution and solid phases will then be separated by centrifugation at 1225 g for 10 min. In between each successive extraction, the solid residues are suspended in 5 ml of 0.1 M NaCl, shaken by hand, and centrifuged to displace extracting solution remaining from the previous step. The supernatant will be added to t he former extractant. The steps are mean to reduce sample dispersion and to minimize read sorption of the metal. The supernatants will be filtered through a 0.45 m membrane, and the solid residues are preserved for the subsequent extractions. The concentrations of Cu, Zn, Pb and Cd in the various extracts will be determined by Inductive Couple Plasma-Mass Spectrometry (ICP-MS). Mass balances, calculated by summing individual Pb, Cd, Cu and Zn masses recovered from fractions, were compared with the independently determined total metal masses.Data AnalysisFurther data analysis will be conducted using the raw data obtained from the sample analysis. Descriptive analysis, cluster analysis, factor Analysis will be conducted using few softwares such as SPSS version 17 and Multivariate Statistical Package (MVSP) and AQUACHEM. Enrichment factors (EF) will be calculated to determine the level of trace metal contamination of the sediments.7.0 Project BenefitResearch Publications2 research jou rnal with impact factorOutput expected from the projectIt is expected that several publication can be produced from the data obtained in this study which useful as a reference for future research.It will provide the latest information on the level of metal pollution in Selangor which practicable for germane(predicate) authority to make the future planning and management purposes.Economic contribution of the projectBy using the information gathered in this research, the relevant government bodies can make better planning and take preventive measures to avoid further contamination of the river as it is crucial source for the nation fisheries and aquaculture activity. Moreover, important because a lot of the population which resides near the mangrove area depend on it for their livelihood. Since, the destruction or contamination of this area will affect their source of income. The reduction in fisheries produce from the mangrove area due to metal pollution will results in higher impo rts of fish products which in turn increase the outflow of money from the country.8.0 ReferencesApello, C.A.J Postma, D. 2005. Geochemistry, groundwater and pollution. 2nd edition. Roterdam Balkema.Birungi, Z., Masola, B., Zaranyika, M. F., Naigaga, I. and Marshall, B. (2008). Active biomonitoring of trace heavy metals using fish (Oreochromis niloticus) as bioindicator speciesthe case of Nakivubo wetland along lake victoria.Chaney, R. L., 2010. Cadmium and Zinc. Trace Element in Soils. Wiley Publication. United Kingdom.Department of Environment, 2007. DOE Annual Report 2007. Retrieved from http//www.doe.gov.my/files/multimedia141/AR_JAS.pdf on 10 October 2010.DID, 2010. Department of Irrigation. River Management-Activities. Retrieved on 5 October 2010 at http//www.water.gov.my/index.php?option=com_contenttask=Forghani et al., 2009. Geochemistry and speciation of metals in sediments of the Maharlu Saline Lake, Shiraz, SW Iran. Environment Earth Science (2009) 59173-184Guevara et al. , 2005. In Yu, R., Yuan, X., Zhao, Y., Hu, G., Tu, X., 2008. Heavy metal pollution in intertidal sediments from Quanzhou Bay, China. Journal of Environment Science 20, 664-669.Howard J. L., Vandenbrink W. J., 1999. Sequential extraction analysis of heavy metals in sediments of variable composition using nitrilotriacetic acid to counteract resorption.Jain, C. K., 2003. Metal fractionation study on bed sediments of River Yamuna, India. Water Research 38 (2004) 569-578Juahir, H., Zain, S., Yusoff, M., Hanidza, T., Armi, A., Toriman, M. and Mokhtar, M., 2010. Spatial water quality assessment of Langat River Basin (Malaysia) using environmetric techniques. Environmental Monitoring and Assessment.Krishnamurti, G. S. R., Huang, P. M., Van Rees, K. C. J., Kozak, L. M. and Rostad, H. P. W., 1995. Speciation of particulate-bound Cadmium of Soils and its bioavailability. Analyst, 120.851.Pempkowiase J., Sikora A., Biernacka E., 1999. Speciation of heavy metals in marine sediments vs their accu mulation by mussels. Chemosphere 199939(2)313-21.Piron, M., Pineau, A. and Mabele, R.M., 1990. Sediment, parameters and distribution of metals in fine sediments of the loire estuary. Water, Air, Amp Soil Pollution 50(3), 267-277.Poh E. L., Mun Y. K., 1994. Determination and speciation of heavy metals in sediments of the Juru river, Penang, Malaysia. Environmental Monitoring Assessment 3585-95, 1995.Sarmani, S., 1989. The determination of heavy metals in water, suspended materials andSediments from Langat River, Malaysia. Hydrobiologia 176/177 233-238, 1989 .Shazili, N.A.M., Yunus, K., Ahmad, A.S., Abdullah, N. and Rashid, M.K.A., 2006. Heavy metal pollution status in the Malaysian aquatic environment. Aquatic Ecosystem Health Management 9(2), 137-145.Silviera, M. L., Alleoni, L. R. F., OConnor, G. A., Chang, A. C., 2006. Heavy metal sequential extraction methods A modification for tropical soils. Chemosphere 64 (2006) 1929-1938.Song, Y., Wilson, M.J., Moon, H.S., Bacon, J.R. and Bain, D.C., 1999. Chemical and mineralogical forms of lead, zinc and cadmium in particle size fractions of some wastes, sediments and soils in Korea. employ Geochemistry 14(5), 621-633.Tan, G. H., (1995). Residue Levels of Phthalate Esters in Water and Sediment Samples from the Klang River Basin. Environment Contamination and Toxicology 54171-1769 1995 Springer-Verlag New York Inc.Tessier, A., Campbell, P. G. C., Bisson, M., 1979. Sequential Extraction Procedure for the Speciation of Particulate Trace Metals. Analytical Chamistry, Vol 51, No 7, June 1979.US EPA, 1996. Method 3050B. Acid digestion of sediments, sludges and soils. Available from http//www.epa.gov/osw/hazard/testmethods/sw846/pdfs/3050b.pdfviewid=16Itemid=395Yap, S.Y. and Ong, H.T. (1990) The effects of agrochemicals on an aquatic ecosystem a case study from the Krian River basin, Malaysia. The Environmentalist 10(3), 189202.Yu, R., Yuan, X., Zhao, Y., Hu, G., Tu, X., 2008. Heavy metal pollution in intertidal sedimen ts from Quanzhou Bay, China. Journal of Environment Science 20, 664-669.

No comments:

Post a Comment