Handling leachate from glass cullet stockpiles

Mixed glass cullet (crushed recycled glass containers) is stockpiled uncovered before use as roadway construction aggregate or daily cover in landfills. Rainwater that leaches through the stockpiles dissolves and suspends contaminants such as those from food residuals and paper labels. The objective of this study was to determine leachate quantity and quality from cullet stockpiles as a basis for development of Best Management Practices (BMPs). Four 35-tonne field stockpiles were set up for leachate analysis and to determine the effects of mechanical turning treatment on the leachate. Field-collected leachate and laboratory-generated washwater of cullet (water:cullet = 3:1 by weight) were both analyzed for basic wastewater parameters, which showed pollutant levels comparable to or higher than those of untreated domestic wastewater or urban stormwater. While organic contamination decreased substantially (e.g., washwater BOD > 95% reduction), TKN and total-phosphorus levels in leachate ranged between 11.6–154 mg L^?1 and 1.6–12.0 mg L^?1, respectively, and remained comparable to levels found in untreated domestic wastewater after four months. Turning enhanced the degradation of the organic constituents inside the stockpiles, which was confirmed by elevated temperatures. Based on this study, leachate from glass cullet stockpiles should not be released to surface water. For leachate from long-term cullet stockpiles, release to groundwater should be only done after treatment to reduce nitrogen levels.     

Uranium and thorium in soils,mineral sands,water and food samples in a tin mining area in Nigeria with elevated activity

The activity concentrations of uranium and thorium have been determined in soils and mineral sands from the Nigerian tin mining area of Bisichi, located in the Jos Plateau, and from two control areas in Nigeria (Jos City and Akure) using high-purity germanium detectors (HPGe). High resolution sector field inductively coupled plasma mass spectroscopy (HR-SF-ICP-MS) was used to determine uranium and thorium in liquids and foodstuffs consumed locally in the mining area. The activities of uranium and thorium measured in the soils and mineral sands from Bisichi ranged from 8.7 kBq kg⁻¹ to 51 kBq kg⁻¹ for ²³⁸U and from 16.8 kBq kg⁻¹ to 98 kBq kg⁻¹ for ²³²Th, respectively. These values were significantly higher than those in the control areas of Jos City and Akure and than the reference values reported in the literature. They even exceeded the concentrations reported for areas of high natural radioactive background. Radionuclide concentrations in samples of the local foodstuffs and in water samples collected in Bisichi were found to be higher than UNSCEAR reference values. The results reveal the pollution potential of the mining activities on the surrounding areas.     

Kinetics of uranium uptake in soft water and the effect of body size,bioaccumulation and toxicity to Hyalella azteca

The kinetics of uptake and the effect of body size on uranium (U) bioaccumulation and toxicity to Hyalella azteca exposed to water-only U concentrations in soft water were evaluated. The effect of body size on U bioaccumulation was significant with a slope of ?0.35 between log body concentration and log body mass. A saturation kinetic model was satisfactory to describe the uptake rate, elimination rate and the effect of gut-clearance on size-corrected U bioaccumulation in H. azteca. The one-week lethal water concentrations causing 50% mortality for juvenile and adult H. azteca were 1100 and 4000 nmol U/L, respectively. The one-week lethal body concentration causing 50% mortality was 140 nmol U/g for juvenile H. azteca and 220 nmol U/g for adult H. azteca. One-week bioaccumulation studies that properly account for body-size and gut-clearance times can provide valuable data on U bioavailability and toxicity in the environment.     

Introduction to project MIDTAL: its methods and samples from Arcachon Bay, France

Microalgae worldwide regularly cause harmful effects, considered from the human perspective, in that they cause health problems and economic damage to fisheries and tourism. Cyanobacteria cause similar problems in freshwaters. These episodes encompass a broad range of phenomena collectively referred to as “harmful algal blooms” (HABs). For adequate management of these phenomena, monitoring of microalgae is required. However, effective monitoring is time-consuming because cell morphology as determined by light microscopy may be insufficient to give definitive species and toxin attribution. In the European Union FP7 project MIDTAL (Microarrays for the Detection of Toxic Algae), we achieved rapid species identification using rRNA genes as the target. These regions can be targeted for probe design to recognise species or even strains. We also included antibody reactions to specific toxins produced by these microalgae because, even when cell numbers are low, toxins can be present and can accumulate in the shellfish. Microarrays are the state-of-the-art technology in molecular biology for the processing of bulk samples for detection of target RNA/DNA sequences. After 36 months, we have completed RNA-cell number–signal intensity calibration curves for 18 HAB species and the analysis of monthly field samples from five locations from year 1. Results from one location, Arcachon Bay (France), are reported here and compared favourably with cell counts in most cases. In general, the microarray was more sensitive than the cell counts, and this is likely a reflection in the difference in water volume analysed with the volume filtered for the microarray an order of magnitude greater.     

Studies of the effects of temperatures and solar radiation on volatilization,mineralization and binding of 14c‐DDT in soil under laboratory conditions

Abstract

The effects of temperatures and solar radiation on the dissipation of ¹⁴C‐p,p'‐DDT from a loam soil was studied by quantifying volatilization, mineralization and binding. The major DDT loss occurred by volatilization, which was 1.8 times more at 45^oC than at ambient temperature (30°C). Mineralization of DDT slowly increased with time but it decreased slightly with increase in temperature. Binding of DDT to soil was found to be less at higher temperatures (35 and 45°C) as compared to ambient temperature. Degradation of DDT to DDE was faster at higher temperatures.

Exposure of non‐sterilized and sterilized soils treated with ¹⁴C‐DDT to sunlight in quartz and dark tubes for 6 weeks resulted in significant losses. Volatilization and mineralization in quartz tubes were more as compared to dark tubes. The volatilized organics from the quartz tubes contained larger amounts of p,p'‐DDE than the dark tubes. Further, higher rates of volatilization were found in non‐sterilized soils than in sterilized soils. The results suggest that faster dissipation of DDT from soil under local conditions relates predominantly to increased volatilization as influenced by high temperature and intense solar radiation.     

Organochlorine burdens in blood of ringed and bearded seals from north-western Svalbard.

Ringed seal (Phoca hispida) and bearded seal (Erignathus barbatus) are the main prey of polar bears (Ursus maritimus), and information on organochlorines (OCs) in these pinniped species is important to understand the transport, fate and effects of persistent organic pollutants in the Arctic ecosystem. Thus, OCs were analysed in blood samples of bearded and ringed seals from the coastal ecosystem of the north-western Svalbard archipelago (Kongsfjorden, 78.55degrees N). The relative contribution of OCs could be ranked as follows: Ringed seal females: sigmaPCB > sigma DDT > sigma CHL > sigma HCH > HCB > Mirex. Ringed seal males: sigma PCB > or = sigma DDT > sigma CHL > sigma HCH > or = HCB > Mirex. Bearded seal females: sigma PCB > sigma HCH > or = sigma CHL > sigma DDT > Mirex > HCB. Bearded seal males: sigma PCB > sigma DDT > or = sigma CHL > sigma HCH > Mirex > or = HCB. The concentrations of sigmaPCB and sigma DDT were higher in ringed seals than in bearded seals, whereas sigma HCH was higher in bearded than in ringed seals. In ringed seal females and males sigma PCB was 337 +/- 95 ng/g (n= 6) and 625 +/- 443 ng/g (n=6), whereas sigma DDT was 165 +/- 47 ng/g (n=6) and 621 +/- 559 ng/g (n = 6), respectively. In bearded seal females and males, sigmaPCB was 159 +/- 132 ng/g (n = 6) and 248 +/- 93 ng/g (n = 5), whereas sigmaDDT was 46 +/- 41 ng/g (n = 6) and 161 +/- 71 ng/g (n = 5), respectively. The inter-species differences are caused by a higher trophic position of ringed seals in the Svalbard ecosystem compared to bearded seals. OC levels in ringed seals at Svalbard are similar to those reported from the North-American Arctic and in the lower range compared to previously reported data from Svalbard.