Combining passive sampling and toxicity testing for evaluation of mixtures of polar organic chemicals in sewage treatment plant effluent

Effluent from sewage treatment plants has been associated with a range of pollutant effects. Depending on the influent composition and treatment processes the effluent may contain a myriad of different chemicals which makes monitoring very complex. In this study we aimed to monitor relatively polar organic pollutant mixtures using a combination of passive sampling techniques and a set of biochemistry based assays covering acute bacterial toxicity (Microtox), phytotoxicity (Max-I-PAM assay) and genotoxicity (umuC assay). The study showed that all of the assays were able to detect effects in the samples and allowed a comparison of the two plants as well as a comparison between the two sampling periods. Distinct improvements in water quality were observed in one of the plants as result of an upgrade to a UV disinfection system, which improved from 24x sample enrichment required to induce a 50% response in the Microtox assay to 84x, from 30x sample enrichment to induce a 50% reduction in photosynthetic yield to 125x, and the genotoxicity observed in the first sampling period was eliminated. Thus we propose that biochemical assay techniques in combination with time integrated passive sampling can substantially contribute to the monitoring of polar organic toxicants in STP effluents.     

Designing effective community relations programs

• Cleanup of a contaminated site is halted as community residents launch a legal challenge against the method that those responsible for the site have selected for remediation.
• Parents and teachers at a public school call for an investigation to determine if substances in the building are making students and staff sick. Midway into the investigation, they also become concerned as to whether the right tests are being performed to detect contamination that may be present, and how they will know what the test results mean.
• Industrial neighbors of a facility oppose its air permit application out of concern for the effects the facility's emissions might have on their own workers.

Virtually no business enterprise or government entity is immune from the potential for public interest in or concern about environmental issues. Within the public arena, environmental issues are rarely viewed only in terms of their scientific, technical, or regulatory merits. Instead, they are invariably intertwined with other issues and perceptions regarding health and safety, property values, social justice, and overall quality of life. As such, environmental issues have the potential to create significant controversy, concern, and opposition among community residents. Fortunately, in many cases, much, if not all, of the anger and fear that community residents feel can be relieved through a substantive dialogue that either corrects misinformation or provides a platform for discussing actions that could, should, or are taking place to remedy a situation. Promoting and sustaining such dialogues is the goal of community relations. This article covers the process of designing and implementing a community relations program plan to address serious or long-term environmental issues surrounding facilities, sites, or projects.     

Comparative toxicity of a zinc salt, zinc powder and zinc oxide to Eisenia fetida, Enchytraeus albidus and Folsomia candida

The pore water zinc concentration and the calcium chloride extracted zinc fraction are higher in the soils spiked with a zinc salt (ZnCl2) compared to soils spiked with zinc oxide or zinc powder. Based on total zinc concentrations in the soil, the acute toxicity of zinc salt to the compost worm Eisenia fetida, the potworm Enchytraeus albidus and the springtail Folsomia candida was lower compared to zinc oxide and zinc powder. However, when expressed on the basis of pore water concentrations or calcium chloride extracted fractions, acute toxicity was higher for zinc salt, which indicated that dermal uptake via the pore water is not the only route of uptake. Chronic toxicity of zinc salt, zinc oxide and zinc powder was similar when based on total concentrations in the soil which again indicates that the pore water route of uptake is not the only route of exposure but that oral uptake is also important.     

The relationship between recruitment processes, familiarity, trust, perceived risk and safety

Introduction and Method

Participants′ perceptions of the safety-related aspects of their organization′s recruitment processes were examined, as were their perceptions of safety aspects associated with new recruits.

Results

One hundred and fifty-four professional fire fighters indicated the trust they held in the safety-related aspects of their organizations′ selection and pre-start training. Perceived trust in pre-start training was negatively correlated (r = -.24, p < .01) with the risk associated with new recruits, and positively correlated (r = .50, p < .01) with ratings of trust in recruits to immediately work safely. Furthermore, trust in recruits to immediately work safely was negatively correlated (r = -.21, p < .01) with crews′ safety behavior toward recruits.

Conclusions

These results are interpreted as particularly dangerous for workers, as new recruits lack familiarity with aspects of their new workplace that cannot be addressed by either selection or pre-start training, making them a risk.

Impact on Industry

Organizations should actively identify new recruits, and encourage existing team members not to immediately trust new recruits to work safely.     

CO2 Capture and Storage with Leakage in an Energy-Climate Model

Geological CO₂ capture and storage (CCS) is among the main near-term contenders for addressing the problem of global climate change. Even in a baseline scenario, with no comprehensive international climate policy, a moderate level of CCS technology is expected to be deployed, given the economic benefits associated with enhanced oil and gas recovery. With stringent climate change control, CCS technologies will probably be installed on an industrial scale. Geologically stored CO₂, however, may leak back to the atmosphere, which could render CCS ineffective as climate change reduction option. This article presents a long-term energy scenario study for Europe, in which we assess the significance for climate policy making of leakage of CO₂ artificially stored in underground geological formations. A detailed sensitivity analysis is performed for the CO₂ leakage rate with the bottom-up energy systems model MARKAL, enriched for this purpose with a large set of CO₂ capture technologies (in the power sector, industry, and for the production of hydrogen) and storage options (among which enhanced oil and gas recovery, enhanced coal bed methane recovery, depleted fossil fuel fields, and aquifers). Through a series of model runs, we confirm that a leakage rate of 0.1%/year seems acceptable for CCS to constitute a meaningful climate change mitigation option, whereas one of 1%/year is not. CCS is essentially no option to achieve CO₂ emission reductions when the leakage rate is as high as 1%/year, so more reductions need to be achieved through the use of renewables or nuclear power, or in sectors like industry and transport. We calculate that under strict climate control policy, the cumulative captured and geologically stored CO₂ by 2100 in the electricity sector, when the leakage rate is 0.1%/year, amounts to about 45,000 MtCO₂. Only a little over 10,000 MtCO₂ cumulative power-generation-related emissions are captured and stored underground by the end of the century when the leakage rate is 1%/year. Overall marginal CO₂ abatement costs increase from a few €/tCO₂ today to well over 150 €/tCO₂ in 2100, under an atmospheric CO₂ concentration constraint of 550 ppmv. Carbon costs in 2100 turn out to be about 40 €/tCO₂ higher when the annual leakage rate is 1%/year in comparison to when there is no CO₂ leakage. Irrespective of whether CCS deployment is affected by gradual CO₂ seepage, the annual welfare loss in Europe induced by the implementation of policies preventing “dangerous anthropogenic interference with the climate system” (under our assumption, implying a climate stabilisation target of 550 ppmv CO₂ concentration) remains below 0.5% of GDP during the entire century.

Alternative antimicrobial compounds to control potential Lactobacillus contamination in bioethanol fermentations

Antibiotics are commonly used to control microbial contaminants in yeast-based bioethanol fermentation. Given the increase in antibiotic-resistant bacteria, alternative natural antimicrobials were evaluated against the potential contaminant, Lactobacillus. The effects of nisin, ?-polylysine, chitosan (CS) and lysozyme were screened against 5 Lactobacillus strains. A standard broth- microdilution method was used in 96-well plates to assess the minimal inhibitory concentration (MIC). L. delbrueckii subsp lactis ATCC479 exhibited maximal MICs with CS, ?-polylysine and nisin (1.87, 0.3125 and 0.05 mg/mL, respectively). Nisin reduced most Lactobacillus strains by 6 log CFU/mL after 48 hours with the exception of L. casei. Synergism occurred when ethylenediaminetetraacetic acid (EDTA) was added with nisin. An MIC of 0.4 mg/mL of nisin combined with the EDTA at an MIC of 1 mg/ml markedly suppressed L .casei by 6 log CFU/mL. In conclusion, alternative antimicrobials proved to be a potential candidate for controlling bacterial contamination in the fermentation process. Synergistic effect of nisin with EDTA successfully inhibited the nisin-resistant contaminant, L. casei.