Social and Behavioral Sciences Commons^™

Fractionation Of Sedimentary Arsenic From Port Kembla Harbour, Nsw, Australia, Glennys A. O'Brien, William E. Price, Bryan E. Chenhall, Muhammad Damris

William E. Price

The binding of arsenic in sediments of the heavily industrialised Port Kembla Harbour, NSW, Australia, has been investigated. Both dredge and core samples have been used to develop a sieving/sequential extraction (SE) procedure. Dredge samples included oxic surficial and deeper anoxic sediment. The main core sample analysed was 18 cm deep, sliced at 2 cm intervals. Sediment was sieved to three size ranges (250 microm) and each of these was then subjected to a four step SE, sequentially solubilizing arsenic as ion exchangeable, 1 M HCl soluble, NH(2)OH.HCl soluble, and strong oxidising acid soluble. Concentrations of 50-500 mg As kg(-1) …

Arsenic Contamination In Groundwater In Vietnam: An Overview And Analysis Of The Historical, Cultural, Economic, And Political Parameters In The Success Of Various Mitigation Options, Thuy M. Ly

Pomona Senior Theses

Although arsenic is naturally present in the environment, 99% of human exposure to arsenic is through ingestion. Throughout history, arsenic is known as “the king of poisons”; it is mutagenic, carcinogenic, and teratogenic. Even in smaller concentrations, it accumulates in the body and takes decades before any physical symptoms of arsenic poisoning shows. According to the World Health Organization (WHO), the safe concentration of arsenic in drinking water is 10 µg/L. However, this limit is often times ignored until it is decades too late and people begin showing symptoms of having been poisoned.

This is the current situation for Vietnam, …

Inorganic Arsenic And Iron(Ii) Distributions In Sediment Porewaters Investigated By A Combined Dgt - Colourimetric Det Technique, William Bennett, Peter R. Teasdale, David T. Welsh, Jarad Panther, Ryan R. Stewart, Helen L. Price, Dianne F. Jolley

Faculty of Science - Papers (Archive)

No abstract provided.

Investigating Arsenic Speciation And Mobilization In Sediments With Dgt And Det: A Mesocosm Evaluation Of Oxic-Anoxic Transitions, William W. Bennett, Peter R. Teasdale, Jarad G. Panther, David T. Welsh, Huijun Zhao, Dianne F. Jolley

Faculty of Science - Papers (Archive)

Mobilization of arsenic from freshwater and estuarine sediments during the transition from oxic to anoxic conditions was investigated using recently developed diffusive sampling techniques. Arsenic speciation and Fe(II) concentrations were measured at high resolution (1−3 mm) with in situ diffusive gradients in thin films (DGT) and diffusive equilibration in thin films (DET) techniques. Water column anoxia induced Fe(II) and As(III) fluxes from the sediment. A correlation between water column Fe(II) and As(III) concentrations was observed in both freshwater (r_s = 0.896, p < 0.001) and estuarine (r_s = 0.557, p < 0.001) mesocosms. Porewater sampling by DGT and DET techniques confirmed that arsenic mobilization was associated with the reductive dissolution of Fe(III) (hydr)oxides in the suboxic zone of the sediment; a relationship that was visible because of the ability to measure the coincident profiles of these species using combined DGT and DET samplers. The selective measurement of As(III) and total inorganic arsenic by separate DGT samplers indicated that As(III) was the primary species mobilized from the solid phase to the porewater. This measurement approach effectively ruled out substantial As(V) mobilization from the freshwater and estuarine sediments in this experiment. This study demonstrates the capabilities of the DGT and DET techniques for investigating arsenic speciation and mobilization over a range of sediment conditions.