Using Wind To Power a Groundwater Circulation Well—Preliminary Results

In areas of the country where the U.S. Department of Energy has classified the available wind resources as Class 3 or greater, the use of wind turbines to provide power to relatively small remediation systems such as groundwater circulation wells may be technically and economically feasible. Groundwater circulation wells are a good candidate technology to couple with renewable energy, because the remediation system removes contamination from the subject aquifer with no net loss of the groundwater resource, while the wind turbine does not create potentially harmful air emissions. Wind data collected in the vicinity of the former Nebraska Ordnance Plant Superfund site were used to select a wind turbine system to provide a portion of the energy necessary to power a groundwater circulation well located in an area of high trichloroethylene groundwater contamination. Because utility power was already installed at the remediation system, a 10 kW grid inter-tie wind turbine system supplements the utility system without requiring batteries for energy storage. The historical data from the site indicate that the quantity of energy purchased correlates poorly with the quantity of groundwater treated. Preliminary data from the wind turbine system indicate that the wind turbine provides more energy than the remediation system treatment components and the well submersible pump require on a monthly average. The preliminary results indicate that the coupling of wind turbines and groundwater circulation wells may be an attractive alternative in terms of the system operation time, cost savings, and contaminant mass removal

Life cycle assessment of biosolids land application and evaluation of the factors impacting human toxicity through plants uptake

Due to the increasing environmental concerns in the wastewater treatment sector, the environmental impacts of organic waste disposal procedures require careful evaluation. However, the impacts related to the return of organic matter to agricultural soils are difficult to assess. The aim of this study is to assess the environmental impacts of land application of two types of biosolids (dried and composted, respectively) from the same wastewater treatment plant in France, and to improve the quantification of human toxicity. A Life Cycle Assessment (LCA) was carried out on a case study based on validated data from an actual wastewater treatment plant. Numerous impacts were included in this analysis, but a particular emphasis was laid on human toxicity via plant ingestion. For six out of the height impact categories included in the analysis, the dried biosolids system was more harmful to the environment than the composting route, especially regarding the consumption of primary energy. Only human toxicity via water, soil and air compartments and ozone depletion impacts were higher with the composted biosolids

Haloalkane hydrolysis by Rhodococcus erythropolis cells: Comparison of conventional aqueous phase dehalogenation and nonconventional gas phase dehalogenation

Biofiltration of air polluted by volatile organic compounds is now recognized by the industrial and research communities as an effective and viable alternative to standard environmental technologies. Whereas many studies have focused on solid/liquid/gas biofilters, there have been fewer reports on waste air treatment using other biological processes, especially in a solid/gas biofilter. In this study, a comparison was made of the hydrolysis of halogenated compounds (such as 1-chlorobutane) by lyophilized Rhodococcus erythropolis cells in a novel solid/ gas biofilter and in the aqueous phase. We first determined the culture conditions for the production of R. erythropolis cells with a strong dehalogenase activity. Four different media were studied and the amount of 1-chlorobutane was optimized. Next, we report the possibility to use R. erythropolis cells in a solid/gas biofilter in order to transform halogenated compounds in corresponding alcohols. The effect of experimental parameters (total flow into the biofilter, thermodynamic activity of the substrates, temperature, carbon chain length of halogenated substrates) on the activity and stability of lyophilized cells in the gas phase was determined. A critical water thermodynamic activity (aw) of 0.4 is necessary for the enzyme to become active and optimal dehalogenase activity for the lyophilized cells is obtained for an aw of 0.9. A temperature of reaction of 40jC represents the best compromise between stability and activity. Activation energy of the reaction was determined and found equal to 59.5 KJ/mol. The pH effect on the dehalogenase activity of R. erythropolis cells was also studied in the gas phase and in the aqueous phase. It was observed that pH 9.0 provided the best activity in both systems. We observed that in the aqueous phase R. erythropolis cells were less sensitive to the variation in pH than R. erythropolis cells in the gas phase. Finally, the addition of volatile Lewis base (triethylamine) in the gaseous phase and the action of the lysozyme in order to permeabilize the cells was found to be highly beneficial to the effectiveness of the biofilter

Refinement of arsenic attributable health risks in rural Pakistan using population specific dietary intake values

Background: Previous risk assessment studies have often utilised generic consumption or intake values when evaluating ingestion exposure pathways. If these values do not accurately reflect the country or scenario in question, the resulting risk assessment will not provide a meaningful representation of cancer risks in that particular country/scenario. Objectives: This study sought to determine water and food intake parameters for one region in South Asia, rural Pakistan, and assess the role population specific intake parameters play in cancer risk assessment. Methods: A questionnaire was developed to collect data on sociodemographic features and 24-hour water and food consumption patterns from a rural community. The impact of dietary differences on cancer susceptibility linked to arsenic exposure was evaluated by calculating cancer risks using the data collected in the current study against standard water and food intake levels for the USA, Europe and Asia. A probabilistic cancer risk was performed for each set of intake values of this study. Results: Average daily total water intake based on drinking direct plain water and indirect water from food and beverages was found to be 3.5 L day-1 (95% CI: 3.38, 3.57) exceeding the US Environmental Protection Agency’s default (2.5 L day-1) and World Health Organization’s recommended intake value (2 L day-1). Average daily rice intake (469 g day-1) was found to be lower than in India and Bangladesh whereas wheat intake (402 g day−1) was higher than intake reported for USA, Europe and Asian sub-regions. Consequently, arsenic-associated cumulative cancer risks determined for daily water intake was found to be 17 in children of 3-6 years (95% CI: 0.0014, 0.0017), 14 in children of age 6-16 years (95% CI: 0.001, 0.0011) and 6 in adults of 16-67 years (95% CI: 0.0006, 0.0006) in a population size of 10000. This is higher than the risks estimated using the US Environmental Protection Agency and World Health Organization’s default recommended water intake levels. Rice intake data showed early life cumulative cancer risks of 15 in 10000 for children of 3-6 years (95% CI: 0.0012, 0.0015), 14 in children of 6-16 years (95% CI: 0.0011, 0.0014) and later life risk of 8 in adults (95% CI: 0.0008, 0.0008) in a population of 10000. This is lower than cancer risks in countries with higher rice intake and elevated arsenic levels (Bangladesh and India). Cumulative cancer risk from arsenic exposure showed the relative risk contribution from total water to be51%, from rice to be44% and wheat intake 5%. Conclusions: The study demonstrates the need to use population specific dietary information for risk assessment and risk management studies. Probabilistic risk assessment concluded the importance of dietary intake in estimating cancer risk, along with arsenic concentrations in water or food and age of exposed rural population

International Frameworks Dealing with Human Risk Assessment of Combined Exposure to Multiple Chemicals

The development of harmonised terminology and frameworks for the human risk assessment of combined exposure to multiple chemicals (“chemical mixtures”) is an important area for EFSA and a number of activities have already been undertaken, i.e. in the fields of pesticides and contaminants. The first step prior to a risk assessment of combined exposure to multiple chemicals is problem formulation defining the relevant exposure, hazard and population to be considered. In practice, risk assessment of multiple chemicals is conducted using a tiered approach for exposure assessment, hazard assessment and risk characterisation. Higher tiers require increasing knowledge about the group of chemicals under assessment and the tiers can range from tier 0 (default values, data poor situation) to tier 3 (full probabilistic models). This scientific report reviews the terminology, methodologies and frameworks developed by national and international agencies for the human risk assessment of combined exposure to multiple chemicals and provides recommendations for future activities at EFSA in this area

Low Carbon Development for Cities: Methods and Measures

Cities consume more than 60% of global energy and that share is expected to rise with the rapid rate of urbanization now underway (van der Hoeven, 2012). Cities\u27 energy consumption, along with the reshaping and resurfacing of land and the food and other resources they demand, lead to a similarly large share of global greenhouse gas (GHG) emissions, carbon-based and otherwise. With cities playing a crucial role in sustainable energy and climate systems, this chapter examines emerging efforts by cities around the world to shift to a development pattern with less energy and less carbon