Heavy Metal Migration Through Clay Below A Domestic Waste Site

Migration of contaminants from a domestic waste landfill overlying a 30 m thick natural clay deposit is presented. Profiles for Na(\u27+), Mg(\u272+), DOC and other soluble species indicate that, at 16 years, contaminants have migrated up to 130 cm from the waste. Profiles for conservative species suggest that Cl(\u27-), (\u273)H, (\u2718)O and (\u272)H fronts are ahead of those of species such as Na(\u27+), K(\u27+) and DOC. In comparison, the heavy metals, Fe, Mn, Cu, Zn and Pb, have migrated only 10-20 cm.;Batch equilibrium studies involving Fe(\u272+), Cu(\u272+), Zn(\u272+) and Pb(\u272+) result in classical adsorption-pH curves which show increasing adsorption at higher pH levels and vice versa. The presence of soil carbonates is shown to significantly increase the mass of Pb and Cu removed from domestic landfill leachate.;Highly reducing conditions in the top 50 cm of the contaminated barrier clay are inferred from laboratory-measured redox potentials. Reduced species of nitrogen (NH(,4)(\u27+)-ammonium) relative to oxidized species (NO(,2)(\u27-)(nitrite) and NO(,3)(\u27-)(nitrate)) is also much more abundant in this zone. Corresponding pH values show little variation in the profile, increasing from about 7.8 at the clay-waste interface to 8.2 in the rest of the profile. Soil bacteriological studies suggest that a higher microbial population exists in the interface region probably due to increased availability of nutrients. It is suggested that a greater depletion of oxygen has, consequently, occurred near the interface.;Combination of E(,h)-pH and selective dissolution data with thermodynamic calculations lead to the evidence that carbonates may be controlling the solubilities of heavy metals in the clay pore water. With the exception of Cu(OH)(,2), the pore water is found to be undersaturated with respect to metal hydroxides. The presence of insoluble metal-organic complexes is also inferred from the selective dissolution analysis.;Volume estimates based on chemical precipitates indicate that soil porosity decreases only slightly from 0.39 at 20 cm and greater depths to 0.375 at the interface. This represents a 4% reduction in porosity. Na(\u27+) and K(\u27+) retardation factors calculated from the porosities, show only slight increases at the interface. From these it is concluded that metal precipitation, higher microbial population and adsorbed Na(\u27+) are possibly all responsible for small decreases in hydraulic conductivity near the interface

ENV-636: SOIL AQUIFER TREATMENT OF SECONDARY EFFLUENTS AND CSOS IN SOUTHWESTERN ONTARIO

Wastewater reclamation is becoming an important alternative for sustainable water resources management and building climate change resiliency in many regions around the world. The purpose of this research was to investigate the polishing of secondary effluents and Combine Sewer Overflows (CSOs) by a laboratory scale Soil Aquifer Treatment (SAT) considering local sub-surface geology and wastewater characteristics. Results show that characteristic soils of southwestern Ontario can effectively polish secondary effluents in terms of BOD5 (64.9% to 100%), e-coli (100%) and total coliforms (100%). However, low removals of DOC (22.81%) and Nitrate (15.17 %) were achieved. Furthermore, low to moderate improvements of CSOs quality were observed with maximum removals of 54.26 % for BOD5, 36.67% for e-coli, 58.15% for total coliforms and 44.83 % for Total Nitrogen. Additionally, de-nitrification of secondary effluents was greatly improved (46.1 % to 100%) by the addition of readily available organic matter, which supports the importance of protecting recharge wetlands for groundwater quality protection. SAT in southwestern Ontario is a feasible alternative for the recharge of non-potable and potable aquifers with secondary effluents. However, for potable aquifers further treatment of wastewater effluents may be required

Geotechnical properties of clay soils in a brine environment.

Dept. of Geological Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1982 .Y364. Source: Masters Abstracts International, Volume: 40-07, page: . Thesis (M.A.Sc.)--University of Windsor (Canada), 1982

Enhancement of Bioremediation and Phytoremediation Using Electrokinetics

This chapter discusses the use of bioremediation and phytoremediation coupled with electrokinetics and presents the elements contributing to the success of the remediation process. A deep discussion and an overview of the current advancement in the biotechnologies are outlined in details. Innovative solutions for challenges facing the field application of the new technology are presented and new directions are proposed. A careful review for contaminated site conditions including pH, temperature, and other factors influencing the behavior of microbial community are presented. Great deal of discussion is around overcoming the adverse effect of electrolysis reactions, which is a by-product of electrokinetics. The discussion includes prolonging the survival of the indigenous bacteria, increase of microbial enzyme secretion, improvement of the indigenous bacteria metabolism, and exploration of metagenomics resources from soil biota. The challenges facing the field application of bioremediation and phytoremediation including the delivery of the electron donors and/or acceptors and nutrients to microorganisms involved in the biodegradation, particularly in clay soils, which has very low hydraulic conductivity, is discussed. The use of electrokinetics in biostimulation application to enhanced degradation of organic pollutant is reviewed. The implementation of bioaugmentation in bioremediation coupled with electrokinetics to enhance the outcome of bioremediation is presented

Equilibrium and Kinetic Studies of Cu(Ii) Removal from Aqueous Solutions Using a Kenyan Micaceous Mineral.

Copper (II) sorption on a Kenyan micaceous mineral (Mica-K) was studied in the batch mode. The effects of different experimental parameters such as; initial concentration, contact time, sorbent dose, pH, particle size, agitation speed, competition and temperature on the kinetics of copper removal were studied. The sorption pattern of copper onto Mica-K followed Langmuir and Freundlich isotherms. Thermodynamic parameters for copper sorption on Mica-K were also determined. X-ray photoelectron spectroscopic (XPS) analysis of metal ion-equilibrated Mica-K, demonstrated that copper, cadmium and Zinc containing nodules existed on the surface of Mica-K

Soil aquifer treatment of secondary effluents and combined sewer overflows in highly permeable soils typical of southwestern Ontario

Wastewater reclamation is becoming an important alternative for sustainable water resources management and building climate change resiliency in many regions around the world. This research investigated the polishing of secondary effluents and combined sewer overflows (CSOs) by a laboratory-scale soil aquifer treatment considering local soils and wastewater characteristics of southwestern Ontario. Results show that high permeability soils of southwestern Ontario, have the ability to polish secondary effluents in terms of dissolved organic carbon, Escherichia coli, and total coliforms. Regarding the simulated CSOs, low to moderate improvements of wastewater quality were observed. Denitrification of secondary effluents improved significantly by the addition of readily available organic matter, which supports the importance of protecting recharge wetlands for groundwater quality protection. Soil aquifer treatment in southwestern Ontario is a feasible alternative for the recharge of non-potable and potable aquifers with secondary effluents. However, for potable aquifers further treatment of wastewater effluents may be required.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Soil cover research to mitigate potential ARD in combined dry and wet closure of tailings storage facility

Non UBCUnreviewedOthe