Analysis of polycyclic aromatic hydrocarbons (PAHs) in airborne particles by direct sample introduction thermal desorption GC/MS

The technique of thermal desorption (TD)–GC/MS was evaluated for measuring airborne, 4–6 ring polycyclic aromatic hydrocarbons (PAHs) collected onto quartz filters. TD provides a more readily automated and sensitive alternative to traditional solvent extraction, decreasing the time/cost of analysis and reducing the risk of analyte loss or sample contamination. The developed method was successfully applied to the analysis of PAH standard solutions loaded on sorbent tubes packed with quartz wool and the graphitized carbon black sorbent Carbograph2. The optimized method showed high desorption efficiency over the whole range of target PAHs with good precision, linearity and sensitivity. The proposed method was verified on an urban dust Standard Reference Material (SRM 1649a); the experimentally determined concentrations agreed with the certified ranges (95% confidence limit) for all target compounds except benzo[a]anthracene, which fell just outside the narrow certified range. The desorption efficiency and the reproducibility of the method was evaluated by analysing pieces of real sample filters sampled from urban air for a period of 24 h. The results confirmed the homogeneity of the filter and showed high recovery efficiencies for all target PAHs.     

Drivers for innovation in waste-to-energy technology.

This paper summarizes developments made in the field of waste-to-energy technology between the 1980s and the present. In the USA, many waste-to-energy systems were developed in the 1980s and early 1990s. These plants generated power relatively efficiently (typically 23%) in 60 bar/ 443 degrees C boilers. Unfortunately, the development came to a stop when the US Supreme Court rejected the practice of waste flow control in 1994. Consequently, waste was directed to mega-landfills, associated with very negative environmental impacts. However, given landfill taxes and increased fuel prices, new waste-to-energy projects have recently been developed. Attractive premiums for renewable power production from municipal waste have been introduced in several European countries. This triggered important innovations in the field of improved energy recovery. Examples of modern waste-to-energy plants are Brescia and Amsterdam with net efficiencies of 24 and 30%, respectively. Incineration is traditionally preferred in Japan due to space constraints. New legislation promoted ash melting or gasification to obtain improved ash quality. However, these processes reduce the efficiency in terms of energy, cost and availability. A new oxygen-enriched waste-to-energy system is under development in order to better achieve the required inert ash quality.     

Disappearance of bromopropylate residues in artichokes, strawberries and beans

Residues of Bromopropylate were determine in artichokes, strawberries and beans after foliar spray of acaricide at two rates. The rates used were 1 g/l formulated product (normal recommended) and 1.5 g/l. The residue levels of bromopropylate in the three crops after 14 days were lower than 0.7 ppm and did not exceed the Maximum Residual Level (MRL) recommended by FAO. In the artichokes and strawberries, the total concentration of residues decreased by 50% of the initial level after 2-3 days. Only trace levels of the bromopropylate residues (less than 0.01 ppm) were detected in the "hearts" of the artichokes. Bromopropylate residues in the green beans were also less than 0.8 ppm after the first day of foliar spraying. The kinetic of degradation occurred in two different steps. In the first step (4-6 days) the dissipation of bromopropylate was faster whereas in the second step (7-14 days) the loss of residues was much slower.     

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.     

Diphenylamine and derivatives in the environment: a review

Diphenylamine (DPA) is a compound from the third European Union (EU) list of priority pollutants. It was assigned by the EU to Germany to assess and control its environmental risks. DPA and derivatives are most commonly used as stabilizers in nitrocellulose-containing explosives and propellants, in the perfumery, and as antioxidants in the rubber and elastomer industry. DPA is also widely used to prevent post-harvest deterioration of apple and pear crops. DPA is a parent compound of many derivatives, which are used for the production of dyes, pharmaceuticals, photography chemicals and further small-scale applications. Diphenylamines are still produced worldwide by the chemical industries. First reports showed that DPA was found in soil and groundwater. Some ecotoxicological studies demonstrated the potential hazard of various diphenylamines to the aquatic environment and to bacteria and animals. Studies on the biodegradability of DPA and its derivatives are very sparse. Therefore, further investigation is required to determine the complete dimension of the potential environmental hazard and to introduce possible (bio)remediation techniques for sites that are contaminated with this class of compounds. This is the first detailed review on DPA and some derivatives summarizing their environmental relevance as it is published in the literature so far and this review will recommend conducting further research in the future.