International Journal of Soil: Volume 2, Issue 3
No Thumbnail Available
Volume
Number
Issue Date
2009-17-12
Journal Title
Journal ISSN
Journal Volume
Articles
Analysis of Sulfur in the Copper Basin and Muddy River Sites
Berger, Michael; Zou, Ling; Schleicher, Robert
The feasiblity of using a portable analytical instrument, the Niton XRF XLt 500He, was tested as a technique for sulfur analysis of wet sediment samples in the field. The effect of sample preparation on the precision and accuracy of sulfur determination was specifically evaluated. The Niton XRF XLt 500He uses X-ray fluorescence (XRF) to detect different elements. This unit employs a helium purge to allow the analysis of elements lighter than potassium. Samples with sulfur varying from 0.3 to 2.0% were successfully measured with the instrument. The precision of the unit is excellent and the limit of detection can be extremely low with careful attention to sample preparation. The instrumental limit of detection for sulfur was estimated as 70 ppm.
Membrane Delivered Ethene to Stimulate Microbial Degradation of DCE
Saleh, Nash; Bandyopadhyay, Aditi; Kavathekar, Avanti; Patel, Kamal; Clapp, Lee
A significant obstacle to the application of microbial reductive dechlorination of PCE and TCE is the undesirable accumulation of cis-DCE and vinyl chloride. In this study, lab-scale aquifer sediment column experiments were conducted to evaluate the feasibility of using ethene to stimulate cometabolic and/or auxiliary aerobic degradation of DCE in aquifer sediments from Edwards Air Force Base (EAFB). A mixture of ethene in air was supplied to gas-permeable membranes installed in a test column to stimulate aerobic degradation of DCE by ethenotrophic populations. Membranes in a parallel column were supplied with air or nitrogen as a negative control. The experimental results indicated that simply supplying ethene and air to the EAFB aquifer sediments alone did not produce conditions favorable for growth of DCE-degrading ethenotrophs. Moreover, amending the aquifer sediments with nutrients and bioaugmenting with enriched and pure (Nocardioides strain JS614) ethenotrophic cultures failed to stimulate growth of DCE-degrading ethenotrophs. This may have been due to the presence of inhibitory substrates or the absence of requisite growth factors. Parallel microcosm studies demonstrated that both the enriched ethenotrophic culture and the Nocardioides strain JS614 culture rapidly cometabolized DCE in mineral salts media, but did not readily acclimate to the EAFB aquifer sediments. The results of the column study and microcosm study together indicated that achieving ethenotrophic degradation of cis-DCE may be more difficult under in situ conditions than under ideal microcosm conditions.
Comparison of Bacterial Levels from Water and Sediments among Upper and Lower Areas of Guion Creek
Yeung-Cheung, Anna K.
Harbor Island Park located in Mamaroneck Harbor was frequently closed due to the exceeding levels of enterococci found in the water. A filter system Gunderboom® BPSTM (Beach Protection System) was installed in 2002 at the beach to lower bacterial levels in the swimming area. Our previous studies in 2006 showed that the densities of E. coli and coliform bacteria recovered from water and sediment were significantly lower inside the Gunderboom® when compared to the outside and the surrounding watersheds: Mamaroneck River, Guion Creek, and Shore Acres Beach. However, higher densities of bacteria were found in Guion Creek which directly drains into the harbor. The current study focuses in the comparison of E. coli and enterococci levels from water and sediment samples collected from the upper areas of Guion Creek (Beaver Swamp, the stream at Rye Neck High School and Upper Guion Creek) and the lower areas of Guion Creek (Lower Guion Creek, outside and inside of the Gunderboom®). Water and sediment specimen were collected bi-weekly at these 6 sites from May to November of 2007, especially after heavy rainfall. The results showed that the densities of E. coli and enterococci were significantly lower inside the Gunderboom® which proved again the effectiveness of the filter in lowering bacteria in water. In addition, the densities of enterococci and E. coli were found significantly higher in water and sediment samples collected in Beaver Swamp, Rye Neck High School and Upper Guion Creek than the other 3 lower regions. In conclusion, our study suggests some non-point source bacterial contamination located in the upper areas of the Guion Creek and may contribute to the increased densities of E. coli and enterococci in the Mamaroneck Harbor.
Influence of Pharmaceutical Effluent on the Physico – Chemical Behavior and Geotechnical Characteristics of Clayey and Silty Soils
Murugaiyan, Vijayarangam; Saravanane, Raman
Single soil – column studies were carried out to understand the influence of pharmaceutical effluent (industrial type) on the physico – chemical behaviour and on the index and strength properties of five soils (two commercial and three natural soils) due to artificial contamination extending to nearly 250 days period. Two modes of operation, two HRTs and two concentrations of effluents, were the parameters considered. The unique role played by the above ‘organic and toxic’ effluent in influencing the physico – chemical behaviour and the index properties of soils are highlighted. It is found that the strengths of the soils have reduced by about 20%, within the period of concentration. Great caution need to be exercised by Geotechnical Engineers and by the various industries, when an ‘organic and toxic’ effluent, is allowed to discharge on a soil mass, containing at least 35% of clay content, when such soil/(s) are to be used for Engineering purposes.
Characterization and Low-Cost Remediation of Soils Contaminated by Timbers in Community Gardens
Heiger-Bernays, Wendy J.; Fraser, Alicia; Burns, Valerie; Diskin, Kerry; Pierotti, Diedre; Merchant-Borna, Kian; McClean, Michael; Brabander, Daniel; Hynes, H. Patricia
Urban community gardens worldwide provide significant health benefits to those gardening and consuming fresh produce from them. Urban gardens are most often placed in locations and on land in which soil contaminants reflect past practices and often contain elevated levels of metals and organic contaminants. Garden plot dividers made from either railroad ties or chromated copper arsenate (CCA) pressure treated lumber contribute to the soil contamination and provide a continuous source of contaminants. Elevated levels of polycyclic aromatic hydrocarbons (PAHs) derived from railroad ties and arsenic from CCA pressure treated lumber are present in the gardens studied. Using a representative garden, we 1) determined the nature and extent of urban community garden soil contaminated with PAHs and arsenic by garden timbers; 2) designed a remediation plan, based on our sampling results, with our community partner guided by public health criteria, local regulation, affordability, and replicability; 3) determined the safety and advisability of adding city compost to Boston community gardens as a soil amendment; and 4) made recommendations for community gardeners regarding healthful gardening practices. This is the first study of its kind that looks at contaminants other than lead in urban garden soil and that evaluates the effect on select soil contaminants of adding city compost to community garden soil.