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Aerobic treatment units (ATUs) are used to enhance or replace traditional septic-tank/drainfield onsite sewage treatment and disposal systems (OSTDS). The objective of the study reported here was to assess the performance of ATUs under real-life conditions. Monroe County Health Department personnel in the Florida Keys sampled two-thirds of approximately 1,200 ATU systems on record during 2000 and 2001. Grab samples were analyzed for five-day carbonaceous biochemical oxygen demand (CBO[D.sub.5]), total suspended solids (TSS), total nitrogen (TN), and total phosphorus (TP). Results showed a non-normally distributed wide range of concentrations from less than 1 to thousands of milligrams per liter. In about half of the grab samples, TSS exceeded 30 mg/L, and in a quarter, CBO[D.sub.5] exceeded 25 mg/L. Concentrations differed significantly (p < .05) by sampling point location, with CBO[D.sub.5] and TSS more affected than TN and TP. These results reflected significantly higher concentrations at sampling ports and additional treatment occurring in system components after treatment by the ATU. Differences by day of week and by month were also significant (p < .05), but time of day was not associated with significant differences. No significant improvement was found with newer ATUs over older ones. The high variability of ATUs and the low frequency of sampling pose a challenge to monitoring and enforcement programs., Introduction The Florida Keys are an ecologically sensitive environment and a destination for growing numbers of permanent and transient visitors. To address the increasing negative ecological effects resulting from increased [...]

We report the [sup.13]C content of preserved organic carbon for a 150 million-year section of late Archean shallow and deepwater sediments of the Hamersley Province in Western Australia. We find a [sup.13]C enrichment of [approximately equal to] 10[per thousand] in organic carbon of post-2.7-billion-year-old shallow-water carbonate rocks relative to deepwater sediments. The shallow-water organic-carbon [sup.13]C content has a 29 [per thousand] range in values (-57 to -28 [per thousand]), and it contrasts with the less variable but strongly [sup.13]C-depleted (-40 to -45[per thousand]) organic carbon in deepwater sediments. The [sup.13]C enrichment likely represents microbial habitats not as strongly influenced by assimilation of methane or other [sup.13]C-depleted substrates. We propose that continued oxidation of shallow settings favored the expansion of aerobic ecosystems and respiring organisms, and, as a result, isotopic signatures of preserved organic carbon in shallow settings approached that of photosynthetic biomass. Facies analysis of published carbon-isotopic records indicates that the Hamersley shallow-water signal may be representative of a late Archean global signature and that it preceded a similar, but delayed, [sup.13]C enrichment of deepwater deposits. The data suggest that a global-scale expansion of oxygenated habitats accompanied the progression away from anaerobic ecosystems toward respiring microbial communities fueled by oxygenic photosynthesis before the oxygenation of the atmosphere after 2.45 billion years ago. organic carbon | isotopes | methanotrophy | oxygen

A gasoline release site at the Dept. of Defense Housing Facility (DODHF) in Novato, Calif., resulted in dissolved methyl tertiary-butyl ether (MTBE) in a shallow, thin, heterogeneous aquifer. Multiple methods were used to evaluate the stability of the MTBE plume, including concentration versus time plots, isoconcentration contour maps, total dissolved MTBE mass and center of mass (COM) estimates, total plume extent changes, and parametric and nonparametric statistical techniques. The COM evaluation revealed a small upgradient shift in COM relative to both total plume extent and total MTBE mass reduction over the period examined. The total mass removal received substantial contributions from both the southern and northern portions of the plume, and the only removal mechanisms active in the northern plume were natural attenuation mechanisms. The results indicate that there exists at DODHF Novato a dissolved MTBE plume at the approximate balancing point between groundwater advection, which is carrying MTBE downgradient, and natural attenuation processes including aerobic biodegradation, which are reducing MTBE concentrations at about the same rate. CE Database keywords: Risk management; Attenuation; Biodegradation; Heterogeneity; Ground water.

Results show that the purified catalase from the Vibrio rumoiensis S-1(sup)T is a 230 kilodalton molecular mass enzyme exhibiting four identical subunits. Data also indicate that the unique properties of the enzyme are consistent with bacterium's exposure to an environment of hydrogen peroxide.

Research performed on a strain of aerobic anoxygenic photosynthetic bacteria reveal the presence of bacteriochlorophyll a (Bchl). The abundance of the the bacteria despite isolation from a deep-ocean hydrothermal vent plume environment indicates that the ability to produce Bchl is of selective advantage. Further studies have to be done to differentiate between the evolution of photosynthesis at deep hydrothermal vents and that in sun-irradiated environments.

Two novel mechanisms are described for granule formation as observed in three laboratory scale sequencing batch reactors operating for biological phosphorus removal and treating two different types of wastewater. The application of the mechanisms and the associated microbial ecology has provided conceptual information benefiting start-up procedures for full-scale granular-sludge reactors.

The effect of experimental choices on the survey of microbial diversity in a sample taken from the aerobic basin of the activated sludge of a North Carolina wastewater treatment plant is studied. The studies have concluded that if the analysis is meant to probe the rare biosphere, both the experimental conditions and analysis choices will have a major impact on the observed results.

The analysis of an extensive partial 16S rRNA gene library of the bacterial community diversity from a single composite sample from an agricultural soil that is generated using very general primers and GC-fractionated DNA is reported. The data obtained indicated that GC fractionation or other prefractionation approaches for reducing complexity within total community DNA prior to PCR and cloning are useful for DNA-based phylogenetic surveys of microbial community diversity.

A new primer set was developed to specifically amplify aoxB genes encoding the As(III) oxidase catalytic subunit from taxonomically diverse aerobic As(III)-oxidizing bacteria. The results highlighted the conservation of essential amino acids and structural motifs and the usefulness of the aoxB gene as a functional marker of aerobic As(III) oxidizers.

A study was conducted to explore the abundance, vertical distribution, and diversity of aerobic anoxygenic phototrophic bacteria (AAP) at four basins of the Baltic Sea. The data obtained for the AAP assemblages showed a mixture of marine and freshwater taxa.

The distribution of the epoxyalkanecoenzyme M transferase in ten mycobacterial strains is presented. Results indicate that 6 strains can be isolated on vinyl chloride and 4 strains from that of ethene. All of the ten species possess enzyme activity and its cognate genes. Data reveal that in the former, the enzyme is encoded on linear megaplasmids.

Research has been conducted on Roseobacter clade strains from different marine habitats. The diversity of these strains has been investigated via the use of 16S rRNA gene as a phylogenetic marker in the effort to correlate phylogeny with ecology, and the results are discussed.

Current processing technology for the production of refuse-derived fuels from municipal solid wastes (MSW) often includes the removal of the high moisture organic fraction composed of food and yard wastes. Digestibility studies reveal that such processed MSW is nutrient deficient. Analysis of nutrient requirements for effective aerobic and anaerobic digestion was conducted in continuous stirred tank rector (CSTR) systems. The effects of nitrogen sources, phosphate, minerals, and complex organics on the ra rate and extent of cellulose polymer hydrolysis is reported.

Aerobic bacteria are very good at degrading waste, up to 50% of the waste becomes more bacteria that in it presents a disposal problem as sludge or biosolids. Anaerobic technology system offering two valuable by-products to companies that generate large volumes of highly concentrated carbohydrate waste is discussed.