Sedimentary hydrocarbon compositions of Estuary-River-Wetland complex system; application of forensic environmental chemistry to assess river ecosystem health
Application of forensic chemistry to assess the health condition of an ecosystem is an alternative method where dominant chemical compounds are considered from various sources. Rivers and related ecosystems such as attached wetlands and estuaries are important environmental compartments for wildlife and marine organisms in reproduction and daily life. A complex of river-wetland-estuary system was evaluated in this study from Mengkabong district of Sabah where southern South China Sea meets the land in North Borneo. Sediment samples were collected using Ekman dredger from 11 study locations consist of a river, an estuary and several attached wetlands. Samples were freeze dried, Soxhlet extracted, cleaned and fractioned in hand packed silica gel glass column and spiked into a Gas Chromatography – Mass Spectrometry instrument for analysis of aliphatic hydrocarbons ranging from C16 to C36. Results have shown that the estuary accumulates the highest amount of normal alkane either from natural or from anthropogenic sources where values reach over 90,000 μg/g d.w. The second highest value of 14 to 26 thousands of μg/g d.w. was observed in attached wetlands near the estuary. The river body where water performs its highest velocity demonstrated a low value of 3417 μg/g d.w. A bridge in which connects vehicle traffic load of the riversides were supposed to show a maximum concentration due to the trap-delay fact of particles has demonstrated a medium level equal to upstream wetlands of the study area. The low concentration of aliphatic hydrocarbons in river and Bridge stations was accompanied by highest low over high molecular weight (L/H) ratio to confirm freshness of either allochthonous or autochthonous input into the study area while other stations revealed old hydrocarbons. The Carbon Preference Index (CPI) values among stations stated that the River station follows the same chemical composition pattern of upstream wetlands where the values of CPI fluctuate from 0.65 to 0.70. The values of Average Chain Length of hydrocarbons (ACL) indicated that downstream environment such as estuary and attached wetlands are more affected by contaminant. The ACL was observed an average of 27.33 in downstream where compared with 28.13 of the upstream. Interestingly, the River station itself has shown the highest value of 29.12 that reveals the lowest effect of anthropogenic sources as the water flow pushes the particles to move towards downstream. Although anthropogenic input has made the downstream environment slightly affected, the aquatic inputs which come from marine and fresh water algae and microorganisms were observed dominant throughout stations with the presence C17 and C19 has been examined. Manmade affects such as petroleum contamination in the study area was examined by the dominance of C16, C18 and C20 that showed the ubiquitous dispersion of this contaminant in negligible concentration might be delivered from the atmospheric influence of surrounding environment such as cars and the presence of only petroleum product processing plant near the study area. The study area in overall showed similar trends of health comparing to some other studied rivers elsewhere.
Chemical Composition Sediment aliphatic environmental health forensic approach
M.Sakari K.M.Kalimin F.A.F.Adnan R.Taira K.Budin S.A.M.Ali
Water Research Unit, School of Science and Technology, Universiti Malaysia Sabah, Jalan UMS, 88400 K School of Science and Technology, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah,
国际会议
The 3rd Biennial ISRS Symposium Achieving Healthy and Viable Rivers (ISRS)第3届国际河流大会
北京
英文
390-397
2013-08-05（万方平台首次上网日期，不代表论文的发表时间）