Uncertainty Estimation in a Remediation Process: A Case Study

A case study concerning the reclamation of a brownfield for residential purposes is presented. Because a high contamination of Polycyclic Aromatic Hydrocarbons (PAHs) was detected in soil, a remediation process is necessary. Bench-scale treat-ability tests were carried out in order to evaluate performances of some remediation technologies on this specific matrix, and particularly for the removal of high-molecular-weight PAHs. Biodegradation studies allowed the evaluation of PAH abatement in a slurry phase treatment, the amount of abiotic losses and the effect of macronutri-ents and bioaugmentation on the removal efficiency. The experimental study was performed in compliance with a Quality System, based on ISO 9001:2000 and ISO/ EC 17025:1999; validation of the analytical method provided the expanded uncertainty of the removal efficiency, varying from nearly 13 to 21%, depending on the compound considered. Experimental results showed a high removal efficiency for all PAHs; the addition of nitrogen and phosphorous increased the removal rate and the efficiency for high-molecular-weight PAHs, whereas no remarkable differences were observed in total (abiotic + biotic) removal of light compounds.     

Remediation of Ammonium-Contaminated Abandoned Animal Waste Lagoon Soil: Physical Properties and Growth of Barley

Remediation of the soil beneath closed animal waste lagoons is an important issue, particularly for lagoons in environmentally sensitive regions. Few studies address the possibility of using plants to remediate these soils. The objectives of this research were to determine whether barley (Hor-deum vulgare L.), a salt-tolerant crop, would grow in lagoon soil and to determine the effect of plant residue amendments on barley growth and soil physical properties. The lagoon soil was collected from a closed swine lagoon. Oat-straw and corn-cob residues were added at rates of 0 (control), 15, 30, 45, 60, and 75?g/kg lagoon soil. Barley grew in all soils, including the soil with no residues. Average grain yield of plants in pots with oat straw was more than twice that of plants in pots with corn cobs (10.7?g/pot and 4.5?g/pot, respectively). Bulk density and oxygen diffusion rate decreased with increasing amounts of residue in the soil. Infiltration was lower in pots with oat straw than in pots with corn cobs. Irrigation water moved rapidly through macropores visible in the soil with corn cobs. The soil amended with corn cobs retained less water, causing poor growth of the barley. The results showed that corn-cob residue created preferential flow paths in the lagoon soil.     

Taxonomy of the Yeast Genus Metschnikowia: a Correction and a New Variety

Metschnikowia isolates from ponds on Chatham Island, New Zealand, previously erroneously reported as M. zobellii, are described herein as M. bicuspidata var. chathamia var. n.     

A Review on Heavy Metals Contamination in Soil: Effects,Sources, and Remediation Techniques

Soil heavy metal pollution has become a worldwide environmental issue that has attracted considerable public attention, largely from the increasing concern for the security of agricultural products. Heavy metals refer to some metals and metalloids possessing biological toxicity, such as cadmium, mercury, arsenic, lead, and chromium. These elements enter the soil agro-ecosystem through natural processes derived from parent materials, and through anthropogenic activities. Heavy metal pollution poses a great threat to the health and well-being of organisms and human beings due to potential accumulation risk through the food chain. Remediation using chemical, physical, and biological methods has been adopted to solve the problem. Phytoremediation has proven to be a promising alternative to conventional approaches as it is cost effective, environmentally friendly, and aesthetically pleasing. To date, based on the natural ability of extraction, approximately 500 taxa have been identified as hyperaccumulators of one or more metals. In addition, further research integrating biotechnological approaches with comprehensive multidisciplinary research is needed to improve plant tolerance and reduce the accumulation of toxic metals in soils. This review discusses harmful effects, sources of heavy metals, and the remediation technologies for soil contaminated by heavy metals.