Assessing the Quality of Surface Sediments in the Tajan River and Determining the Level of Ecological Pollution

Rivers, as the living artery of the watershed, have caused its life and have long determined the extent and establishment of civilizations, especially in the coastal plains. The Tajan River in the coastal plain of Sari has been directly polluted by water and sediment resources as a result of industrialization, agricultural development, and towns, and villages. The aim of this study was to determine the quality of surface sediments of Tajan River in the city to sea range based on the concentration of toxic elements As, Cr, Cd, Cu, Ni, Pb, Zn and to detect the level of pollution caused by them. The sampling strategy was designed to collect 25 surface sediment samples based on the distribution of point and non-point pollution sources and river morphology. Samples were conditioned and concentration of toxic elements and sulfur were measured using ICP-MS at dry weight with accuracy of mg/kg and percentage of total organic carbon. Using enrichment factor and sediment quality standards (ISQGs, PEL, SEL), the level of contamination caused by toxic elements was detected. The results well identified the polluted and clean ranges of the Tajan River. Accordingly, the southeast and downstream of the urban area of Sari were polluted by the toxic metal of As and upstream of the urban area, and adjacent to the effluent of industrial estates to the river were contaminated considerably by the toxic metal of chromium. Finally, superficial sediments of the Tajan River along the studied range were polluted significantly by the toxic metal of Ni at a risky level. Also, Pb enrichment was proven in the downstream sediments of the urban area due to fossil fuels. The research results emphasize the effect of urban-rural pollution (surface water drainage, construction waste and rubbish), industrial and agricultural effluents and sand mines on the pollution of water resources and sediment of Tajan River

Oil palm plantations are large sources of nitrous oxide, but where are the data to quantify the impact on global warming?

Oil palm plantations have rapidly expanded over the last 30 years, and now occupy 10% of the world’s permanent cropland. The growth of one of the world’s most efficient and versatile crop has alleviated poverty and increased food and energy security, but not without side effects. Losses of forest biodiversity hits the news. Although equally important, climate change issues have not reached this limelight. Data on greenhouse gas emissions associated with oil palm production is limited, especially for the potent greenhouse gas nitrous oxide (N2O). This paper provides an overview of the data availability, and identifies knowledge gaps to steer future research to provide the data required for climate change models and more accurate international and national nitrous oxide emission accounting

Sedimentation rate in Bera Lake and soil redistribution at its catchment using radioisotopes / Mohammadreza Gharibreza

The Bera Lake is a lacustrine system and the largest natural lake in Malaysia. Assessment of literature review has highlighted a clear gap in the evaluation of environmental impacts of anthropogenic activities on the soil and water resources and sedimentary regime. Accordingly, determination of soil and nutrient redistribution in the catchment area, and sedimentation rates, nutrients fate and sediment quality assessment at Bera Lake using fallout 210Pb and 137Cs radioisotopes and sediment quality guidelines have been defined as aims of the present research. A comprehensive methodology was formulated to perform an effective literature review, innovation of core sampler, field surveying, detailed experimental measurements, mapping, and an advanced modeling. A wide range of models and a geo-referenced “GIS-ready” data set have supported the designed methodology. Application of fallout 137Cs inventories and proportional model provide the mean of soil erosion of 914±345, 117±36, and 70±35, t h-1 y-1 in cleared lands, immature and mature oil palm plantations. A negative correlation between nutrient contents and the extent of land development was established in the study area Stratigraphic dates based on records of fallout 137Cs and 210Pb supply rates to Bera Lake sediment columns have remained relatively constant. As a result, the CRS model is applied for geochronology of Bera Lake sediments. The estimated maximum 210Pb flux and sedimentation rate were 159±2 Bq cm-2 y-1 and 2.56 cm y-1, respectively in the semi-closed area at the north of Bera Lake. The mean pre-1950 sedimentation rate was 0.08±0.02 g cm-2 y-1 (0.1±0.1cm y-1), which indicate a uniform accumulation trend prior to anthropogenic activities. Sedimentation rates raised were by 10 times since 1972 following deforestation. Accordingly, a white sandy mud layer was deposited between 1972 and 1993 at the south, middle, and the north of Bera Lake at mean rates of 0.48±0.48, 0.54±1.2 and 0.17±0.12 g cm-2 y-1. Establishment of mature oil palm plantations are promoting biomass productivity to 1.5 mil y-1, dominates organic matters in run-off and accumulation of organic-rich deposits at mean rate of 0.2±0.1 g cm-2 y-1 (1.3 cm y-1) at the uppermost layer of Bera Lake sediment sequence since 1994. Overall sedimentation rates in Bera Lake basin using 210Pb date and CRS model, fallout 137Cs and proportional model, and trap efficiency and sediment discharge values were 0.99, 1.025, and 1.11 cm y-1, respectively. Sediment quality guidelines have shown that lake deposits severely polluted by As and the north part polluted by Fe. Besides, Bera Lake sediment profiles are moderately polluted by Cu, Cr, and Ni. A clear eutrophication in Bera Lake has occurred due to deforestation phases in the catchment area. To sum up, achievements have confidently approved capability of selected methods to achieve the research objective. Present study has remarkably contributed in knowledge due to formulation of the suitable method to estimate soil erosion in oil palm plantations in Malaysia, and sedimentation rates and reconstruction history of a natural lake, assessment of sediment quality and an integrated management plan for a sustainable land use and conservation of water and soil

An Evaluation of Bera Lake (Malaysia) Sediment Contamination Using Sediment Quality Guidelines

Bera Lake is known as the first RAMSAR site and is the largest natural lake in Malaysia. Sediment quality guidelines (SQGs) and Geoaccumulation index were used to evaluate Bera Lake sediment contamination. Five undisturbed cores were collected from Bera Lake sediment. Major and trace levels of elements were determined for 132 subsamples using an inductively coupled plasma mass spectrometry (ICP-MS). The results marked two major groups of metallic elements bonded to the terrestrial and organic-rich sediments. Terrestrial sediments were strongly associated with accumulation of Li, Al, Pb, Cu, Cr, Na, Mg, Sr, and K during main fluxes of metals. However, a strong positive correlation was obtained between Fe, Mn, As, Zn, Cu, Ni, Ca, and Cd elements and TOC and TN. The Mn/Fe ratio revealed a long-term redox and acidic condition at Bera Lake. Geoaccumulation index for all individual metals has classified Bera Lake sediment as low to moderately polluted. However, elemental values when compared with thresholds limits of SQG indicated that Bera Lake sediments were contaminated by arsenic and iron. Results prove that deforestation during the five phases of land developments since 1972 has significantly contributed to the existence of metals fluxes into the area