Hydrodynamic Controls of Particulate Metals Partitioning Along the Lower Selenga River—Main Tributary of The Lake Baikal

In this study, the downstream effects of pollutants spreading due to hydromorphological gradients and associated changes in sediment transport conditions along the braided-meandering and deltaic distributary reach of a large river downstream section are discussed. We demonstrate the significance of hydrodynamic control for sediment-associated metal partitioning along the river. Typically, the downward decline of the sediment and metals spreading towards Lake Baikal is observed due to buffer effects in the delta. During peak flow, the longitudinal gradients in heavy metal concentration along the distributary delta reach are neglected due to higher concentrations delivered from the upper parts of the river. In particular, significant variations of heavy metal concentrations associated with the river depth are related to sediment concentration and flow velocity profiles. Various particulate metal behavior in silt-sand delta channels and the sand–gravel Selenga main stem emphasize the importance of near-bottom exchange for particles spreading with the river flow. Using empirically derived Rouse numbers, we found quantitative relationships between the ratio of particulate metals sorting throughout depth in a single river channel and the hydrodynamic conditions of sediment transport.

Particulate trace metal dynamics in response to increased CO₂ and iron availability in a coastal mesocosm experiment

Rising concentrations of atmospheric carbon dioxide are causing ocean acidification and will influence marine processes and trace metal biogeochemistry. The importance of the combined impacts of elevated CO2 and changes in trace metal availability on marine plankton remain largely unknown. A mesocosm experiment was performed to study changes in particulate trace metal concentrations during a bloom dominated by the coccolithophore Emiliania huxleyi. We employed a full-factorial experimental design, comprising all combinations of ambient and elevated pCO2 and dissolved iron (dFe). Particulate metal concentrations (Fe, Cu, Zn, Co, Mn, Cd, Mo, Ti and Pb) were determined by high-resolution inductively coupled plasma mass spectrometry (HR-ICPMS). We examined biogenic and lithogenic sources of particulate metals, and their evolution during the experiment. Biogenic metal concentrations were estimated from bulk particle measurements by comparing phosphorus (P)-normalised quotas with published ratios, as well as concentrations of particulate trace metals in the presence and absence of an oxalate-EDTA wash. Our results demonstrate that particulate Ti and Fe concentrations were dominated by lithogenic material in the fjord. In contrast, particulate Cu, Co, Mn, Zn, Mo and Cd concentrations correlated with P concentrations and phytoplankton biomass, indicative of their strong biogenic character. Furthermore, ocean acidification changed the relative concentrations of particulate metals; a result mainly driven by the effects of ocean acidification on the growth of different phytoplankton phyla. This study demonstrates the utility and robustness of combining trace metal analyses of particles in a controlled mesocosm experiment with manipulations of CO2 and Fe concentrations using natural assemblages of marine phytoplankton.

ANALISIS KIMIA LIMBAH B3 UNTUK MENENTUKAN EFISIENSI PENGHANCURAN DALAM UJI BAKAR DI INSINERATOR

Salah satu cara efektif mengurangi limbah bahan berbahaya dan beracun (B3) yaitu dengan membakarnya dalam insinerator. Berbagai keuntungan pembakaran limbah dalam insinerator mendorong usaha memanfaatkannya untuk menghacurkan limbah B3 di Indonesia. Keputusan Menteri Lingkungan Hidup (Men-LH) no. 18/2009memungkinkan orang mendapat ijin pengolahan limbah B3 melalui insinerator, tetapi berdasarkan Keputusan Kepala BAPEDAL No.: Kep-03/1995, mereka harus memenuhi persyaratan efisiensi penghancuran (DRE) sebesar 99,99% atau lebih, dan juga persyaratan lainnya. Pembuktian efisiensi penghancuran dilakukan melalui kegiatanuji bakar (TBT). Sebelum uji bakar dilakukan, analisis kimia limbah harus dilakukan di laboratorium. Senyawa yang paling sulit terbakar dalam uji bakar dapat dipilih berdasarkan nilai bakar senyawa dari hasil analisis tersebut. Dalam penelitian ini analisis kimia dari tiga jenis limbah B3, sarung tangan terkontaminasi, lumpur dari instalasi pengolahan limbah dan limbah infeksius rumah sakit, telah dilakukan. Hidrokarbon organic utama (POHC) yang dianalisis dari ketiga limbah ini adalah 1.1 Dichlorethylene, 1.1.1 Trichloroethylene dan Tetrachloroethylene dengan konsentrasi masing-masing sebesar 1.411, 0.311, dan 0.166 mg/kg. Hasil perhitungan indek panas pembakarannya masing-masing adalah 38.45, 57.78 and 84.20. Jadi, Tetrachloroethylene merupakan POHC yang paling sulit terbakar sehingga terpilih sebagai wakil semua POHC yang mungkin terkandung dalam limbah B3 tersebut dalam uji bakar. Sampling untuk emisi Tetrachloroethylene menggunakan metode baku US EPA No. 30. Dalam uji bakar disarankan untuk mengukur emisi partikulat, logam-logam berat, asam khlorida (HCl) dan gas-gas emisi lainnya ((O2, CO, CO2, laju alir gas emisi, kadar air gas) dengan metode sampling baku. Data-data ini dapat digunakan untuk melakukan koreksi dan membantu dalam perhitungan hasil sampling. Kata Kunci: Limbah Bahan Berbahaya dan Beracun (B3), Uji Bakar (TBT), Efisiensi Penghancuran (DRE), Indek Panas Pembakaran (I), Senyawa Hidrokarbon Organic Utama (POHC). AbstractOne effective way to reduce industrial hazardous wastes is to burn them in the incinerators. A variety of advantages of the waste incineration has caused businesses on employing incinerator for hazardous waste destruction in Indonesia. Regulation of the State Minister for the Environment No. 18/2009 allows business people to have licensesto treat hazardous waste through incinerator but according to the Decree of the Head of the Environmental Management Agency (BAPEDAL) No.: Kep-03/1995 they must meet requirement of achieving 99.99% or more destruction removal efficiency (DRE) and other requirements. A demonstration of achieving DRE is done through a trial burn test (TBT). Prior to TBT, the chemical analyses of the wastes need to be done in the laboratory.Themost difficult compund to be burned in the TBT can be selected based on concentrations and heating values of those results. In this research, chemical analyses of three kinds of waste, contaminated gloves, wasterwater treatment sludge, and infectious medical wastes, have been carried out. The principal organic hydrocarbons (POHCs) analyzedare found to be 1.1 Dichlorethylene, 1.1.1 Trichloroethylene and Tetrachloroethylene with the respective average concentrations of 1.411, 0.311, and 0.166 mg/kg. The respective calculated heat of combustion indexs are 38.45, 57.78 and 84.20. Thus, Tetrachloroethylene is a POHC that is most difficult to be burned and therefore it ischosen to be a representation of all POHCs of the wastes for TBT. Sampling method of Tetrachloroethylene emission uses US EPA Method 30 –Volatile Organic Sampling Train (VOST). During TBT it is also suggested to measure particulate, metals, chloride acid (HCl), and other emitted gases (O2, CO, CO2, gaseous emission rate, gas watercontent) with standard sampling methods. These data could be use to standarize and support the calculationn of the sampling results. Key words: Hazardous wastes, Trial Burn Test (TBT), Destruction Removal Efficiency (DRE), Heat of Combustion Index (I), Principal Organic Hydrocarbons (POHCs).

Seasonal influences on the levels of particulate Cd, Cr and Pb in Kuantan River, Pahang

Introduction: Temporal and spatial variations of selected toxic element distributions were studied in the Kuantan River waters. Methods: Water samples from 9 sampling stations were taken from downstream of the estuary towards the upstream of the Kuantan River during the rainy and dry season. Particulate Cd, Cr and Pb were filtered, dried, weighed and analyzed using Teflon Bomb digestion processes. Results: The concentration of particulate Cd, Cr and Pb were in the range of ND to 14.480 mg L-1 , 6.047 to 271.497 mg L1 and 0.646 to 174.859 mg L-1 , respectively. The distribution of the elements in suspended particulate matter was found influenced by the rainy season and dry season. Particulate metals obtained mostly higher in May 2012 (dry season) while Cd and Cr were found above the limits authorize by the International Commission for the Protection of the Rhine against Pollution (ICPR). Conclusions: Correlation matrix between various parameters revealed that most of the parameters were found to bear a statistically significant correlation with each other.