Operation of a 27‐m3 biopile for the treatment of petroleum‐contaminated soil

Soil and groundwater contamination due to petroleum hydrocarbon spills is a frequent problem worldwide. In Mexico, even when programs oriented to the diminution of these undesirable events exist, in 2000, a total of 1,518 petroleum spills were reported. Exploration zones, refineries, and oil distribution and storage stations frequently are contaminated with total petroleum hydrocarbons (TPH); diesel fraction; gasoline fraction; benzene, toluene, ethyl benzene, and xylenes (BTEX); and polycyclic aromatic hydrocarbons (PAHs). Among the many methodologies available for the treatment of this kind of contaminated soil, bioremediation is the most favorable, because it is an efficient/low‐cost option that is environmentally friendly. This article discusses the capability of using a biopile to treat soils contaminated with about 40,000 mg/kg of TPH. Design and operation of a 27‐m³ biopile is described in this work, including microbiological and respirometric aspects. Parameters such as TPH, diesel fraction, BTEX, and PAHs considered by the U.S. Environmental Protection Agency were measured in biopile samples at 0, 2, 4, 6, 8, 10, and 22 weeks. A final average TPH concentration of 7,300 mg/kg was achieved in 22 weeks, a removal efficiency of 80 percent. © 2007 Wiley Periodicals, Inc.     

Assessment of heavy metals in the particulate matter of two Brazilian metropolitan areas by using <Emphasis Type="BoldItalic">Tillandsia usneoides</Emphasis> as atmospheric biomonitor

Purpose  

The aims of this paper were to quantify the heavy metals (HM) in the air of different sites in Rio de Janeiro (RJ) and Salvador (SA) using Tillandsia usneoides (Bromeliaceae) as a biomonitor, and to study the morphology and elemental composition of the air particulate matter (PM) retained on the Tillandsia surface.     

Subsoil TPH contamination in two oil pipeline pumping stations and one pipeline right-of-way in north Mexico

This investigation deals with the characterization carried out in zones around two pipeline pumping stations and one pipeline right-of-way in the north of Mexico. In particular those areas where contamination was evaluated: (a) south area of the separation ditch in the Avalos station, (b) the area between the separation ditch at the Avalos station, (c) km 194 + 420 of the Moctuzma station, and (d) km 286 + 900 in the Candelaria station. Results of this investigation showed that only four samples showed TPH values higher than the Mexican limit for 2004: AVA 1B, with 21,191 mg kg^?1; AVA 1C, with 9348 mg kg^?1; AVA 2B, with 13,970 mg kg^?1; and MOC 2A, with 4108 mg kg^?1.None of the sampled points showed the presence of PAHs at values higher than those found in the Mexican or American legislations. PAH were detected in the range of 0.0004 and 13.05 mg kg^?1.It is suggested to implement surfactant soil washing as a remediation technique for the approximately 600 m³ that need to be treated.     

Heavy Metals in Macroalgae of Havana's Northern Littoral, Cuba

Copper, iron, lead, manganese, and zinc contents were determined in various phyla of macroalgae typical of the rocky mesolittoral zone of Cuba and widely distributed in the Caribbean Region. the samples were collected in different zones along the shores of Havana City which are more or less influenced by anthropogenic activities. Differences in metal contents were observed due to seasonal variations and differences between sampling sites. of the analyzed species, only one brown alga, Padina vickersiae is considered as a suitable candidate for the monitoring of metal contamination.     

Toxicity of the nerve agent tabun to Daphnia magna, a new experimental species in military toxicology

Daphnia magna, a freshwater microcrustacean, is currently tested as an alternative experimental species in research dealing with nerve agents poisonings treatment. Because of this, the toxicity of the nerve agent tabun (a cyanide-group containing organophosphate) to Daphnia had to be examined by estimating the EC₅₀ values. The immobilization of daphnids was chosen as the end-point. It was found that D. magna is sensitive to small amounts of tabun, even after 15 min exposure, and tabun toxicity increases with time. The estimated EC₅₀ values for 15, 30, 45, and 60 min exposure were as follows: 67.39, 38.10, 26.95, and 21.9 μg l^-1. In addition, the toxicity of media to which tabun was added 24 h before the start of experiments was examined. The results obtained indicate that daphnids can be used in experiments with nerve-agent intoxication treatment.