Synthesis of poly(hydroxyalkanoate) from hydrolyzed linseed oil

Pseudomonas putida was grown on a mixture of long-chain fatty acids obtained by hydrolysis of linseed oil. A poly(3-hydroxyalkanoate) containing 51.2% of unsaturated monomers was obtained. A considerable percentage (13.6%) was constituted by C₁₄ and C₁₆ monomers containing three double-bonds in the side chains. The polymer showed a high tendency to crosslink when it was kept in presence of air. In the crosslinked polymer no polyunsaturated monomers could be detected.     

Environmental Auditing and the Role of the Accountancy Profession: A Literature Review

This review of the literature on environmental auditing and the potential role of accountants distinguishes between compliance audits and audits of the environmental management system. After an extensive introduction to the concept, this review focuses on the similarities and differences between an environmental audit and a financial statement audit. The general approach to both types of audits is similar, except that environmental audits are largely unregulated. Both audits place an emphasis on the evaluation of control systems, which is an argument in favor of external auditors playing a role in environmental audits. Another argument for including external accountants is their code of ethics. However, these professionals seem to be reluctant to enter the field of environmental auditing. It is argued that this reluctance is because of a lack of generally accepted principles for conducting environmental audits. If external accountants are engaged in environmental auditing, they should be part of multidisciplinary teams that also include scientists and engineers to avoid a too strong focus on procedures. Rather than treating these audits as totally different, it is proposed that there be a move towards integrated, or even universal, audits.     

Comparative effects of mine wastes on the benthos of an acid and an alkaline pond

Benthic invertebrates collected from an acid (pH 3.2) and an alkaline (pH 7.9) tailing pond in the Rouyn-Noranda mining region were compared with those of a control pond in order to assess the effects of the pH on the benthic community structure and on metal accumulation by invertebrates. The acid pond showed high mean soluble concentrations of aluminium (2600 ppb), copper (230 ppb), iron (6500 ppb) and zinc (4900 ppb) in the water and high mean concentrations of copper (340 ppm), iron (15,238 ppm) and zinc (445 ppm) in the sediments. The benthic fauna was dominated by Chironomus spp and the water beetle Ilybius sp. The Shannon-Weaver diversity index was 0.04. The alkaline pond had high mean sediment concentrations of cadmium (21 ppm), iron (15,823 ppm), manganese (658 ppm) and nickel (146 ppm). A total of 37 insect genera and a diversity index of 3.4 were recorded for this pond. Of the seven metals studied only copper and aluminium showed greater accumulations in the biota of the contaminated ponds than in that of the control. Insects dominated the benthic fauna in both contaminated ponds and crustacea in the control.     

Dissipation of DDT in a heavily contaminated soil in Mato Grosso, Brazil

After the prohibition of organochlorine-pesticide use in Brazil for controlling insect vector diseases, Mato Grosso State gathered the exceeding DDT and stored it irregularly in an open air area that belongs to the National Health Foundation, causing soil contamination. This study aimed to evaluate the contamination level and dissipation of p,p'-DDT and p,p'-DDE in this area. For that, surface soil samples were collected on 19 September 2000, 15 December 2000, 4 April 2001 and soil samples 30-40 cm; 60-70 cm and 90-100 cm deep were taken from five points in the studied area on 17 July 2001. The contaminants were determined by a small scale method which consists on extraction and clean-up steps combined into one step by transferring soil samples mixed with neutral alumina to a chromatographic column prepacked with neutral alumina and elution with hexane:dichloromethane (7:3 v:v). The eluate was concentrated and the analytes were quantified by gas chromatography with an electron-capture detector. p,p'-DDT at surface soil ranged from 3,800 to 7,300 mg kg(-1). 30-40 cm deep soil sample concentrations varied from 0.036 to 440 mg kg(-1) while 90-100 cm deep samples varied from 0.069 to 180 mg kg(-1). Volatilization is probably the main dissipation process. The p,p'-DDT is moving slowly downward in the soil profile, however, the levels of this contaminant are high enough to present risk to underground waters.     

Influence of aeration rate on nitrogen dynamics during composting

The paper aimed to study the influence of aeration rate on nitrogen dynamics during composting of wastewater sludge with wood chips. Wastewater sludge was sampled at a pig slaughterhouse 24h before each composting experiment, and mixtures were made at the same mass ratio. Six composting experiments were performed in a lab reactor (300 L) under forced aeration. Aeration flow was constant throughout the experiment and aeration rates applied ranged between 1.69 and 16.63 L/h/kg DM of mixture. Material temperature and oxygen consumption were monitored continuously. Nitrogen losses in leachates as organic and total ammoniacal nitrogen, nitrite and nitrate, and losses in exhaust gases as ammonia were measured daily. Concentrations of total carbon and nitrogen i.e., organic nitrogen, total ammoniacal nitrogen, and nitrite and nitrate were measured in the initial substrates and in the composted materials. The results showed that organic nitrogen, which was released as NH4+/NH3 by ammonification, was closely correlated to the ratio of carbon removed from the material to TC/N(org) of the initial substrates. The increase of aeration was responsible for the increase in ammonia emissions and for the decrease in nitrogen losses through leaching. At high aeration rates, losses of nitrogen in leachates and as ammonia in exhaust gases accounted for 90-99% of the nitrogen removed from the material. At low aeration rates, those accounted for 47-85% of the nitrogen removed from the material. The highest concentrations of total ammoniacal nitrogen in composts occurred at the lowest aeration rate. Due to the correlation of ammonification with biodegradation and to the measurements of losses in leachates and in exhaust gases, the pool NH4+/NH3 in the composting material was calculated as a function of time. The nitrification rate was found to be proportional to the mean content of NH4+/NH3 in the material, i.e., initial NH4+/NH3 plus NH4+/NH3 released by ammonification minus losses in leachates and in exhaust gases. The aeration rate was shown to be a main parameter affecting nitrogen dynamics during composting since it controlled the ammonification, the ammonia emission and the nitrification processes.     

Amelioration of physical strength in waste foundry green sands for reuse as a soil amendment

To avoid increasing costs of landfill disposal, it has become increasingly important for U.S. foundries to identify beneficial reuses for the 8 to 12 million tons of waste foundry sand (WFS) generated annually. A major drawback to the reuse of some WFSs as a soil amendment is their high soil strength, under dry conditions, where root growth may be limited. Fifteen WFSs were analyzed for strength to rupture using lab-formed clods, exchangeable cations (Na, Mg, Ca), metal oxide concentration (Fe, Mn, Al, Si), cation exchange capacity (CEC), and % clay. Several WFS samples from gray iron foundries demonstrated high strength to rupture values (> 1.5 MPa), and could potentially restrict root growth in amended soils. The percentage of Na-bentonite exhibited a positive correlation (R(2) = 0.84) with strength to rupture values. When WFSs containing more Na-bentonite were saturated with 1 mol L(-1) Ca ions, strength values decreased by approximately 70%. Waste foundry sands containing less Na-bentonite were saturated with 1 mol L(-1) Na ions and exhibited a threefold increase in strength. Additions of gypsum (up to 9.6 g kg(-1) sand) to high strength waste foundry sands also caused decreases in strength. These results indicate that high strength WFSs have properties similar to hardsetting soils which are caused by high Na(+) clay content and can be ameliorated by the addition of Ca(2+).     

What is needed to improve tropical conservation? Appropriate education, training, and encouragement

Currently, there is a need for a better multidisciplinary education system for tropical conservation, as well as a need for more people from developing countries to receive such improved education and training. If this combination is achieved, universities in both developed and developing nations will likely produce graduates who are better prepared for jobs involving non-academic tropical conservation initiatives and, simultaneously produce graduates who may be better accepted as conservationists in tropical destinations.     

Effective EU and Member State policies for stimulating CCS

Although CO₂ capture and storage (CCS) is widely recognised as an option to mitigate climate change, consistent and effective EU policies to advance CCS are still absent. This paper discusses policy instruments for advancing large-scale deployment of CCS in the European Union, and evaluates them in a multi-criteria analysis. The EU Emissions Trading Scheme (EU-ETS) is a cost-effective instrument for limiting greenhouse gas emissions, but it is questionable whether its currently limited time horizon and short-trading periods will lead to substantial CCS diffusion. Complementary policies at the EU and the Member State level may repair this and provide sufficient incentives for CCS. Potential policies include financial instruments such as investment subsidies, a feed-in scheme, or a CO₂ price guarantee, as well as a CCS mandate or a low-carbon portfolio. These policy options differ with respect to their environmental effectiveness, possible interaction with the EU-ETS, costs and financial risk involved, and their competition with other mitigation options. Interactions between Member State policies and the EU-ETS are smaller in scope than those of EU-wide policies, but they are more likely to lead to displacement of financial resources from other low-carbon technologies. In addition, national policies may pose a significant part of the financial risk of CCS operations with Member States, reducing the operator's incentive to innovate. Overall, structural policies at the EU level, such as a mandate or a low-carbon portfolio standard would be more conducive for realising large-scale deployment of CCS across the EU as well as more acceptable to environmental organisations.