An evaluation of olive-tree bark for the biological monitoring of airborne trace-elements at ground level

There is a need to start looking into the possibility of tree bark for biomonitoring. Bark from olive trees (Olea europaea Linn.) has been collected over an area in northwestern Portugal, featuring a blend of rural lands, industrial towns and coastal environments. Samples were analysed through INAA and PIXE for their elemental contents. Results from both techniques were reconciled and then compared with an extensive database on 46 trace elements in Parmelia spp. thalli from the same sites and mostly from the very bark substrates. Distribution-free, nonparametric statistics show that, despite signal magnitude, variation patterns of bark and lichen concentrations follow one another in a most significant way. Selected elements in bark also correlate to a superior extent. As far as this investigation goes, there is no reason whatsoever for discarding bark as an alternative to lower epiphytes.     

Removal of hydrocarbons from wastewater using treated bark

This paper explores the possibility of removing hydrocarbons (HCs) and trace elements from synthetic and industrial effluents using treated bark as biosorbent. Coniferous bark was treated either chemically (Tc) or biologically (Tb) to eliminate soluble organic compounds of bark. The removal efficiency (RE) of the HCs from a synthetic oil-water mixture containing spent diesel motor oil exceeds 95% using 2 g/L of treated bark mixed with a synthetic oil-water mixture containing 2 g/L of spent oil. Under these conditions, the retention capacity (RC) was approximately 1 g HC/g dry substrate. The sorption reaction seems to be quasi-instantaneous, and the retention capacity of spent oil on treated bark increases as the temperature augments. This implies that the retention mechanism is related to the capillary action. Results of Fourier transform infrared (FTIR) spectroscopy indicate that spent oil is mainly composed of alkanes. They also suggest that no chemical bonds between Tc and spent oil were established. Measurement of the surface tension of spent oil and the wetting index of the bark suggests that only spent oil will be retained by the substrate. Treatment of an industrial effluent containing 14.4 g/L of total HCs was performed using Tc. It was possible to remove 97% of HCs and retain some trace elements such as Al, Ca, Fe, Mg, S, and so on.     

Das neue Chemikalienprogramm von UNEP Chemicals

Zusammenfassung  UNEP International Register of Potentially Toxic Chemicals (IRPTC) wurde von der ersten VN-Umweltkonferenz 1972 geschaffen. Sein Einfu? und Zusammenwirken in den 80ziger Jahren mit anderen internationalen Programmen der WHO, FAO, OECD und EG in der Chemikalienkontrolle wird beschrieben. Nach dem Erdgipfel von Rio 1992 werden im VN-Rahmen drei neue Gremien gebildet, die das Fachprogramm des Kapitels 19 der Agenda 21 (umweltfreundliches Chemikalienmanagement) umsetzen sollen: die United nations Commission of Sustainable Development, das Intergovernmental Forum on Chemical Safety und das Interorganization Programme for the Sound Management of Chemicals. Der Erdgipfel brachte auch für IRPTC eine Neuorientierung. Seit 1996 hat UNEP Chemicals, wie sich IRPTC nunmehr nennt, drei Aufgaben in sein Arbeitsprogramm aufgenommen, die beschrieben werden: das internationale übereinkommen zum Prior Informed Consent, das internationale übereinkommen zur Kontrolle der Persistent Organic Pollutants, und schlie?lich sein traditionelles Arbeitsgebiet des Informations-austausches über Stoffe wird weitergeführt.

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Die Aussagen dieses Beitrages sind die Meinung des Autors. Sie müssen nicht mit der Auffassung des Umweitbundesamtes oder von UNEP Chemicals übereinstimmen.     

PBDF and PBDD from the combustion of bromine containing flame retarded polymers: A survey

The formation of polybrominated dibenzofurans (PBDF) and dibenzodioxins (PBDD) during the pyrolysis of different polymers containing brominated organic flame retardants was investigated. The pyrolyses were conducted at two different temperatures (600°C and 800°C) using three different oven configurations. Both the pyrolysis gases and the solid residues were analysed for PBDF and PBDD.

PBDF were found in almost all samples, but both the concentration and the degree of bromination varied greatly. The largest yields of PBDF in the percent range were measured in the pyrolysis products of polymers containing brominated diphenyl ethers. The other flame retardants generally yielded only a few ppm of PBDF. PBDD are formed only in a few samples and related to the PBDF in very low concentrations.     

Environmental chemistry of PCB-replacement compounds - V - the metabolism of chloro-isopropylbiphenyls in fish,frogs, fungi and bacteria

The metabolism of 2,5-dichloro-4'-isopropylbiphenyl and 4-chloro-4'-isopropylbiphenyl, two model compounds for alkylated chlorobiphenyls (Chloroalkylenes), has been investigated in fish, frogs, fungi and mixed cultures of bacteria. Fish (Carassius auratus) and frogs (Rana aesculenta) show a very limited metabolism of these compounds. A pure strain of fungus (Cunninghamella echinulata Thaxter) metabolized 2,5-dichloro-4'-isopropylbiphenyl both by stepwise oxidation of the isopropyl group to 2,5-dichloro-4'-biphenylcarboxylic acid and by hydroxylation of the chlorine substituted phenyl ring. A mixed culture of aerobic bacteria from activated sludge shows extensive degradation of 4-chloro-4'-isopropylbiphenyl to p-chlorobenzoic acid via stepwise oxidation of the isopropyl group when using the compound as sole carbon source. However, in the presence of D-glucose as additional carbon source, no metabolism is observed.     

Influence of the application of sewage sludge on the degradation of pesticides in the soil

A study was made of the influence of the application of sewage sludge on the degradation of pesticides in the soil. Two kinds of sludge were used, with different characteristics, one from an urban treatment plant and one from a food processing plant. Three organophosphorus insecticides, fenitrothion, diazinon and dimethoate, were studied. The relative importance was determined of the chemical and biological degradation processes, which involved experiments on soil and sterile soil samples. A comparative study was also made of the degradation of pesticide residues and the evolution of the microbial population. The application of sludge seems to have a complex effect on the degradation of pesticides, determined by the bioavailability and biodegradability of their active ingredient. The biodegradation of pesticide residues brings about alterations in the microorganism population of the soil.     

Comparison of supercritical fluid extraction and Soxhlet extraction for the determination of PCBs in seaweed samples

The efficiency of supercritical fluid extraction for the determination of 12 polychlorinated biphenyls from algae samples is compared to Soxhlet extraction. Analytical detection limits for the individual congeners ranged from 0.62 microgl(-1) to 19 microgl(-1). Recovery was tested for both methods using standard addition procedure. At maximum spike level of concentration, the mean recoveries were not significantly different (P>0.05) of all PCBs studied, with the exception of PCBs 28, 52, 77 and 169. Method precision for Soxhlet extraction (< or =3.9%) was slightly better than for SFE (< or =9.2%). Although both methods yield comparable results, SFE offers the advantage of detecting all PCBs studied at lower concentrations, reducing extraction time, and reducing the amount of solvents needed. The optimized methods were applied to the analysis of three real seaweed samples, except for PCB101 the concentrations of all PCBs were low or below the detection limits. The levels of PCB101 found in sample 1 were 6.6+/-0.54 ng g(-1) d.w., in sample 2 the levels were 8.2+/-0.86 ng g(-1) d.w. and in sample 3 they were 7.7+/-0.08 ng g(-1) d.w.     

Presence of nitro-chlorinated dioxins on fly ash from municipal incinerators and from laboratory production through reactions between NO2 and T4CDD on fly ash

Treatment of tetrachlorodibenzo-p-dioxin (T₄CDD) on municipal incinerator fly ash at 30 to 150°C for 10 minutes using 5% (Vol/Vol) NO₂ in air resulted in production of nitro-T₄CDD. Percent conversion was between 40% at 50°C to 100% at 150°C. Nitro-T₄CDD produced in the laboratory was unstable in hexane/methanol or hexane/acetone solutions and decomposed at ?5°C with half-lives of 8–10 days^?1 to the original T₄CDD.Fly ash from a municipal incinerator in Toronto, Ontario was extracted using toluene/methanol for 12 hrs in a Soxhlet extractor. Condensate of this extract was analyzed using capillary gas chromatography with flame ionization, nitrogen-selective, and mass spectrometric detectors. Retention times for nitro-T₄CDD, multi-ion selected ion monitoring, and nitrogen detector response were used as supporting evidence for the presence of nitro-chlorinated dioxins as naturally occurring in this sample.     

A new photodegradable molecule as a low impact ballast water biocide: efficacy screening on marine organisms from different trophic levels

Marine species carried by the ships’ ballast waters are a potentially serious environmental problem. Many strategies are being adopted to minimize the transfer of invasive or pathogenic marine species between different aquatic ecosystems. This problem is often addressed by using biocides for ballast water treatment; however, the biocide could be dangerous to native organisms once the ballast water is discharged. Chemical treatments such as chlorination and addition of glutaraldehyde could cause problems related to toxicity and application costs. The search for new effective molecules with a low environmental impact is pressing. This paper presents data from a preliminary efficacy screening of a promising molecule derived from alkylated naphtoquinones on a battery of ballast water model organisms. Results show that this new molecule is very effective in the absence of light and is extremely photodegradable (half-life <6 h). It can thus be easily degraded when released in the environment. Physical and Chemical Impacts on Marine Organisms, a Bilateral Seminar Italy-Japan held in November 2004.