BACKGROUND AND AIMS Natural regeneration of white spruce (Picea glauca) after disturbance has been reported to be very poor. Here a study was made to determine whether C compounds released from understorey species growing together with white spruce could be involved in this regeneration failure, either by (1) changing soil nutrient dynamics, (2) inhibiting germination, and/or (3) delaying seedl...

A comprehensive assessment of heavy metals and organic content was performed for leachates produced from a number of old and new landfills in Jordan over 9 month in efforts to set a framework for treatment regulations. All leachates were basic (pH = 7 9) and have high electric conductivity and high organic contents (COD = 3000 500,000 mg/L, TOC= 500 21,000 mg/L). The organic content was inverse...

Landfill leachates are often treated on-site before disposal to municipal wastewater treatment plants, although variations in leachate composition and organic loading continue to have negative impacts on downstream treatment processes. Leachate samples were collected from four landfills both before and after on-site treatment to evaluate the extent of biological treatment. The samples vary in a...

In spite of their low concentrations in soil solutions, low–molecular weight organic substances (LMWOS) such as amino acids, sugars, and uronic acids play a major role in the cycles of C and N in soil. With respect to their low concentrations and to possible matrix interferences, their analysis in soil leachates is a challenging task. We established two HPLC (high-performance liquid chromatogra...

This research describes the use of a toxicity assay for the identification of metal toxicity, bioavailability and heavy metal binding capacity (HMBC) of municipal solid waste (MSW) landfill leachates. MetPLATE, an assay specific for heavy metal toxicity, was used to determine the HMBC of MSW leachates collected from 14 sites in Florida, with a wide range of chemical and physical characteristics...

We have identified a natural clay mixture that exhibits in vitro antibacterial activity against a broad spectrum of bacterial pathogens. We collected four samples from the same source and demonstrated through antibacterial susceptibility testing that these clay mixtures have markedly different antibacterial activity against Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA)...

OBJECTIVE The aim of the study was to investigate the ability of two organic dusts, wool and grain, and their soluble leachates to stimulate secretion of tumour necrosis factor (TNF) by rat alveolar macrophages with special reference to the role of lipopolysaccharide (LPS). METHODS Rat alveolar macrophages were isolated by bronchoalveolar lavage (BAL) and treated in vitro with whole dust, dus...

Several factors were studied to determine their effects on hatch and emergence of second-stage juveniles (J2) from cysts of Heterodera zeae. The optimum temperature for emergence of J2 from cysts of H. zeae was 30 C. No juveniles emerged from cysts at 10 or 40 C. Immersion of cysts in 4 mM zinc chloride solution stimulated 10% greater emergence of J2 than occurred in tap water controls during 2...

Few studies have considered the environmental impacts of impurities and byproducts associated with low-efficiency nanomanufacturing processes. Here, we study the composition and aquatic toxicity of low-purity, as-produced fullerenes (C60) and metallofullerene waste solids, both of which were generated via arc-discharge synthesis. Scanning electron microscopy with energy dispersive X-ray spectro...

Introduction: We report the Cr isotope compositions of differential dissolution steps (leachates) of Murchison, as a companion report to the results on the partial dissolution residues of Orgueil and Murchison in [1, 2]. We also present preliminary results on Ni measurements on the first two Murchison leachates. There has been extensive Cr isotope work on leachates of carbonaceous chondrites, s...