有机碳对混合菌群亚硝酸盐氮氧化的影响

自养硝化过程在自然界氮素循环和污水处理系统脱氮过程中起着关键作用。因此，了解有机碳对硝化的影响和硝化菌与异养菌之间的竞争对微生物生态学和污水处理系统设计都很重要。目前对氨氧化到硝酸盐氮过程的研究文献很多，但对亚硝酸盐氧化过程在异养菌的存在下如何受到有机碳影响的研究甚少。本文从生理生化指标、基因组学、蛋白组学三方面考察了在实验室条件下有机碳（乙酸钠）对硝化细菌和异养菌组成的混合菌群的硝化性能、菌群结构及代谢功能的变化的影响。 全文分为两大部分： 第一部分为乙酸钠对游离态硝化混合菌群的硝化性能和菌群结构的短期影响。混合菌株先在自养条件下进行连续培养，两个月后硝化速率达到20 mg N/(L·d)；而后离心收集菌体进行批式实验。在批式反应器中，初始亚硝氮均为126mg N/ L，乙酸钠-C 与亚硝酸盐-N 的比分别为0，0.44，0.88，4.41，8.82。结果表明：在低C/N 比（0.44 和0.88）时，亚硝酸盐去除速率比C/N=0 下高，细菌呈现一次生长；而在高C/N 比（4.41 和8.82）时，出现连续的硝化反硝化，亚硝酸盐去除率仍比对照下高，细菌呈现二次生长。不同C/N 比下微生物群落明显不同，优势菌群从自养和寡营养细菌体系（包括亚硝酸盐氧化菌，拟杆菌门,α-变形菌纲,浮霉菌门和绿色非硫细菌下的一些菌株）过渡到异养和反硝化菌体系 （γ-变形菌纲的菌株尤其是反硝化菌Pseudomonas stutzeri 和P. nitroreducens 占主导）。 第二部分为乙酸钠对硝化混合菌群生物膜的硝化性能和菌群结构的长期影响。接种富集的硝化混合菌群于装有组合式填料的三角瓶中，于摇床中自养培养；两个月后填料上形成生物膜的硝化速率达到20 mg N/ (L·d)；而后进行长期实验，每12 小时更换混合营养培养基（亚硝氮约200 mg N/ L，C/N 比同上）。结果显示：相较于C/N 比=0 时的亚硝酸盐氧化反应来说，低C/N 比出现了部分的反硝化，而高C/N 比则是几乎完全的反硝化。与对照比，C/N=0.44 时亚硝酸盐氧化速率并未受乙酸钠的影响，反而上升了，但C/N=0.88 时亚硝酸盐氧化速率有所下降。菌群结构分析表明自养对照与混合营养下微生物群落的不同；PCR-DGGE未检测出混合营养下硝化杆菌的存在，而显示异养菌尤其是反硝化菌的大量存 在。荧光定量PCR 结果表明随C/N 比上升，硝化杆菌数量从2.42 × 104 下降到1.34× 103 16S rRNA gene copies/ ng DNA，反硝化菌由0 增加至2.51 × 104 nosZgene copies/ ng DNA。SDS-PAGE 的结果表明不同C/N 比下的蛋白组较为复杂且呈现一定的差异性。 有机碳对亚硝氮氧化及微生物群落的影响很复杂，本文分别讨论了对游离态和生物膜固定态两种状态的混合菌群相应的短期和长期影响研究。研究发现，有机碳并非一定带来硝化的负影响，如果控制在适当的C/N 比范围，有机碳是有利于亚硝氮氧化的。这些发现阐明了有机碳和硝化反硝化的关系，填补了硝化微生物生态学上的空白，对污水处理系统中减少异养菌的影响并提高氮去除率有一定理论指导意义。 Nitrification plays a key role in the biological removal of nitrogen in both nature and wastewater treatment plant (WWTP). So, understanding of the effect of organic carbon on nitrification and the competition between nitrifying bacteria and heterotrophic bacteria is important for both microbial ecology and WWTP design and operation. Despite the fact that the nitrification process of ammonia to nitrate has been extensively investigated, it is not known how the process of nitrite oxidization is affected by organic carbon when heterotrophic bacteria are present. By measuring different physiological and biochemical parameters, as well as using genomic DNA and proteome analysis, we investigated the influence of organic (acetate) on nitrite oxidizing performance, community structure and metabolic function of nitrite-oxidizing and heterotrophic bacteria under laboratory conditions. The dissertation involves two parts: Part one deals with the effect of organic matter on functional performance and bacterial community shift of nitrite-oxidizing and heterotrophic bacteria under suspended state. The bacteria were prepared in a continuous-flow stirred reactor under autotrophic condition; after two months, the nitrification rate of the culture reached about 20 mg N/ (L·d); then the bacteria were harvested for the next batch experiments. The initial concentrations of nitrite were 126 ± 6 mg N/ L in all flasks, and sodium acetate (C) to nitrite (N) ratios were 0, 0.44, 0.88, 4.41, and 8.82, respectively. The results showed that at low C/N ratios (0.44 or 0.88), the nitrite removal rate was higher than that obtained under autotrophic condition and the bacteria had single growth phase, while at high C/N ratios (4.41 or 8.82), continuous aerobic nitrification and denitrification occurred besides higher nitrite removal rates, and the bacteria had double growth phases. The community structure of total bacteria strikingly varied with the different C/N ratios; the dominant populations shifted from autotrophic and oligotrophic bacteria (NOB, and some strains of Bacteroidetes, Alphaproteobacteria, Actinobacteria, and green nonsulfur bacteria) to heterotrophic and denitrifying bacteria (strains of Gammaproteobacteria, especially Pseudomonas stutzeri and P. nitroreducens). Part two describes the influence of acetate on nitrite oxidizing performance, community structure and metabolic function of nitrite-oxidizing and heterotrophic bacteria in biofilms. Bacterial enrichments was transferred into flasks with polypropylene carriers and cultured under agitated and autotrophic condition. After two month, the biofilms grown on the carriers had a nitrification rate of about 20 mg N/ (L·h); then the biofilms were refreshed with mixotrophic medium (nitrite were 200 mg N/ L in all flasks, and C/N ratios was the same as above) every 12 h. the results show: normal nitrite oxidization reactions were performed when C/N = 0, but nitrite oxidization and partial denitrification occurred with low C/N ratios (0.44 or 0.88). At high C/N ratios (4.41 or 8.82), we mainly observed denitrification. In contrast to C/N = 0, the nitrite oxidization rate was unaffected when C/N = 0.44, but decreased with C/N = 0.88. The structure of bacterial communities varied significantly between autotrophic and mixotrophic conditions. Nitrobacter was hard to detect by PCR-DGGE while heterotrophs and especially denitrifiers were in the majority under mixotrophic conditions. Real-time PCR indicated that the Nitrobacter population decreased from 2.42 × 104 to 1.34 × 103 16S rRNA gene copies/ ng DNA, while the quantity of denitrifiers obviously increased from 0 to 2.51×104 nosZ gene copies/ ng DNA with an increasing C/N ratio. SDS-PAGE indicated the complexity of and a certain difference between the proteome of nitrite-oxidizing and heterotrophic bacteria at different C/N ratios. We conclude that the influence of organic matter on nitrite oxidation and the community structure of NOB and heterotrophic bacteria is complex. In this dissertation, we focused on how sodium acetate influenced the system both under suspended state and in biofilms. We observed that acetate did not necessarily have a negative impact on nitrification. Instead, an appropriate amount of acetate benefited both nitrite oxidization and denitrification. These findings provide a greater understanding about the relationship between organics and nitrification; they fill the gaps in the field of microbial ecology of nitrifying bacteria; they also provide insight into how to minimize the negative impact of heterotrophic bacteria and maximize the benefit of nitrogen removal in biological treatment systems.

Enhancing the Performance of the Organic Light-emitting Device (OLED) by Thermal Treatment

A comparative study on the annealing of the ITO substrates and the organic layers were conducted on Organic light-emitting device (OLED). We fabricated four devices with the structure of Al/Alq(3)/TPD: PVK/NiO/ITO/Glass, and investigated the effect of heat on device performance by selectively annealing. When the TPD: PVK layers were annealed at 90 degrees C with 30 min annealing time and the ITO substrates were annealed at 300 degrees C with a constant annealing time (100 min). We find the OLED shows obvious performance improvement in brightness and current efficiency, which is attributable to the fact that annealing reduces defects and improves the interface structures of the organics and the organic/ITO interfaces. On the other hand, an appropriate annealing would slow the transportation of the hole, thus finally leads to more balanced electron and hole.

Ultrasound-promoted chiral fluorescent organogel

In this paper, we have described a chiral binaphthyl-based fluorescent organogel. Very interestingly, similar to sonocrystallisation of organics, ultrasound can promote the gelation while it cannot occur spontaneously at relatively high temperature or low concentration. The fluorescence enhancement of the gel obtained via ultrasound irradiation is observed. In solution there exist rapid dynamic equilibria between (S)-1 oligomers. The association interactions both between gelator molecules and between solvent and gelator molecules could together effect the helical growth of distorted (S)-1 nanocrystals.

Involvement of incipient hydrous oxide species in electrocatalysis at some metal electrode surfaces

In this thesis a novel theory of electrocatalysis at metal (especially noble metal)/solution interfaces was developed based on the assumption of metal adatom/incipient hydrous oxide cyclic redox transitions. Adatoms are considered as metastable, low coverage species that oxidise in-situ at potentials of often significantly cathodic to the regular metal/metal oxide transition. Because the adatom coverage is so low the electrochemical or spectroscopic response for oxidation is frequently overlooked; however, the product of such oxidation, referred to here as incipient hydrous oxide seems to be the important mediator in a wide variety of electrocatalytically demanding oxidation processes. Conversely, electrocatalytically demanding reductions apparently occur only at adatom sites at the metal/solution interface - such reactions generally occur only at potentials below, i.e. more cathodic than, the adatom/hydrous oxide transition. It was established that while silver in base oxidises in a regular manner (forming initially OHads species) at potentials above 1.0 V (RHE), there is a minor redox transition at much lower potentials, ca. o.35 v (RHE). The latter process is assumed to an adatom/hydrous oxide transition and the low coverage Ag(l) hydrous oxide (or hydroxide) species was shown to trigger or mediate the oxidation of aldehydes, e. g. HCHO. The results of a study of this system were shown to be in good agreement with a kinetic model based on the above assumptions; the similarity between this type of behaviour and enzyme-catalysed processes - both systems involve interfacial active sites - was pointed out. Similar behaviour was established for gold where both Au(l) and Au(lll) hydrous oxide mediators were shown to be the effective oxidants for different organic species. One of the most active electrocatalytic materials known at the present time is platinum. While the classical view of this high activity is based on the concept of activated chemisorption (and the important role of the latter is not discounted here) a vital role is attributed to the adatom/hydrous oxide transition. It was suggested that the well known intermediate (or anomalous) peak in the hydrogen region of the cyclic voltanmogram for platinum region is in fact due to an adatom/hydrous oxide transition. Using potential stepping procedures to minimise the effect of deactivating (COads) species, it was shown that the onset (anodic sweep) and termination (cathodic sweep) potential for the oxidation of a wide variety of organics coincided with the potential for the intermediate peak. The converse was also shown to apply; sluggish reduction reactions, that involve interaction with metal adatoms, occur at significant rates only in the region below the hydrous oxide/adatom transition.

In situ concentration of semi-volatile aerosol using water-condensation technology

The effect of concentrating semi-volatile aerosols using a water-condensation technology was investigated using the Versatile Aerosol Concentration Enrichment System (VACES) and the Aerodyne Aerosol Mass Spectrometer (AMS) during measurements of ambient aerosol in Pittsburgh, PA. It was found that the shape of the sulfate mass-weighed size distribution was approximately preserved during passage through the concentrator for all the experiments performed, with a mass enhancement factor of about 10-20 depending on the experiment. The size distributions of organics, ammonium and nitrate were preserved on a relatively clean day (sulfate concentration around 7μg/m3), while during more polluted conditions the concentration of these compounds, especially nitrate, was increased at small sizes after passage through the concentrator. The amount of the extra material, however, is rather small in these experiments: between 2.4% and 7.5% of the final concentrated PM mass is due to "artifact" condensation. An analysis of thermodynamic processes in the concentrator indicates that the extra particle material detected can be explained by redistribution of gas-phase material to the aerosol phase in the concentrator. The analysis shows that the condensation of extra material is expected to be larger for water-soluble semi-volatile material, such as nitrate, which agrees with the observations. The analysis also shows that artifact formation of nitrate will be more pronounced in ammonia-limited conditions and virtually undetectable in ammonia-rich conditions. © 2004 Elsevier Ltd. All rights reserved.

Characterisation of the South West European Marine Sites: Summary Report. Occasional Publication of the Marine Biological Association 14

The UK and EU have recently committed to an ecosystem-based approach to the management of our marine environment. In line with the requirements of the Habitats regulations, all consents likely to significantly affect Special Areas of Conservation (SACs) and Special Protection Areas (SPAs) are to be reviewed. As part of this process, 'site characterisation' is seen as an important first step towards the improved management of designated sites. This characterisation series, undertaken by the Marine Biological Association of the United Kingdom and funded by the Environment Agency and English Nature, sets out to determine the current status of designated marine sites in South West England, and how vulnerable (or robust) they are to contaminants (metals, organics, nutrients) and other anthropogenic pressures. Using published information and unpublished data-sets from regulatory agencies, conservation bodies and research institutes (particularly those of the PMPS*), evidence is compiled on the links between potentially harmful 'activities', environmental quality, and resultant biological consequences. This includes an evaluation of long-term change. The focus is the effect of water and sediment quality on the key interest features of European Marine sites in the South West of England, namely: - Fal and Helford cSAC (MBA Occasional Publication 8) - Plymouth Sound and Estuaries cSAC/ SPA (MBA Occasional Publication 9) - Exe Estuary SPA (MBA Occasional Publication 10) - Chesil and the Fleet cSAC/ SPA (MBA Occasional Publication 11) - Poole Harbour SPA (MBA Occasional Publication 12) - Severn Estuary pSAC/SPA (MBA Occasional Publication 13) Detailed analysis for each of these sites is provided individually. The summary report contains an overview of physical properties, uses and vulnerability for each of these sites, together with brief comparisons of pollution sources, chemical exposure (via sediment and water) and evidence of biological impact (from bioaccumulation to community-level response). Limitations of the data, and gaps in our understanding of these systems are highlighted and suggestions are put forward as to where future research and surveillance is most needed. Hopefully this may assist the statutory authorities in targeting future monitoring and remedial activities. * PMSP: Plymouth Marine Sciences Partnership, comprising the Marine Biological Association (MBA), University of Plymouth (UoP), the Sir Alister Hardy Foundation for Ocean Science, and Plymouth Marine Laboratories (PML)

Emissions of CH3Br, organochlorines, and organoiodines from temperate macroalgae

The production rates of a range of low molecular weight halogenated organics have been determined in cultures of five temperate species of macroalgae collected from the north coast of Norfolk, England. Compounds studied included CH3Br, the chlorinated organics CH3Cl, CH2Cl2 and CHCl3, and the iodinated organics CH3I, C2H5I, and CH2ClI. Measurements of a wider range of halocarbon concentrations in an isolated rockpool and in air over the seaweed bed were also conducted to evaluate the local impact of the seaweeds on halocarbon concentrations in the natural environment. Estimates for the global emissions of some of the key halogenated compounds from macroalgae have been derived. In general macrophytes appear not to be globally significant producers of the particular halocarbons studied. In coastal regions, however, the impact on local atmospheric composition and chemistry could be greater.

Air–sea fluxes of oxygenated volatile organic compounds across the Atlantic Ocean

We present air-sea fluxes of oxygenated volatile organics compounds (OVOCs) quantified by eddy covariance (EC) during the Atlantic Meridional Transect cruise in 2012. Measurements of acetone, acetaldehyde, and methanol in air as well as in water were made in several different oceanic provinces and over a wide range of wind speeds (1-18 m s(-1)). The ocean appears to be a net sink for acetone in the higher latitudes of the North Atlantic but a source in the subtropics. In the South Atlantic, seawater acetone was near saturation relative to the atmosphere, resulting in essentially zero net flux. For acetaldehyde, the two-layer model predicts a small oceanic emission, which was not well resolved by the EC method. Chemical enhancement of air-sea acetaldehyde exchange due to aqueous hydration appears to be minor. The deposition velocity of methanol correlates linearly with the transfer velocity of sensible heat, confirming predominant airside control. We examine the relationships between the OVOC concentrations in air as well as in water, and quantify the gross emission and deposition fluxes of these gases.

A web-based overview of semiconductor photochemistry-based current commercial applications

The major current commercial applications of semiconductor photochemistry promoted on the world wide web are reviewed. The basic principles behind the different applications are discussed, including the use of semiconductor photochemistry to: photo-mineralise organics, photo-sterilise and photo-demist. The range of companies, and their products, which utilise semiconductor photochemistry are examined and typical examples listed. An analysis of the geographical distribution of current commercial activity in this area is made. The results indicate that commercial activity in this area is growing world-wide, but is especially strong in Japan. The number and geographical distribution of patents in semiconductor photocatalysis are also commented on. The trends in the numbers of US and Japanese patents over the last 6 years are discussed. (C) 2002 Elsevier Science B.V. All rights reserved.

Toxicity assessment of xenobiotic contaminated groundwater using lux modified Pseudomonas fluorescens

A bacterial bioassay, suitable for rapid screening to assess the relative toxicity of xenobiotic contaminated groundwater has been developed. The quantitative bioassay utilizes a decline in luminescence of the lux marked soil bacterium Pseudomonas fluorescens on exposure to contaminated groundwaters from which effective concentration (EC) values can be assessed and compared. P. fluorescens was most sensitive to semi-volatile organics in groundwaters but there was no correlation between EC value and chemical content. The sensitivity and reproducibility of the P. fluorescens bioassay was compared with that of Microtox and results showed that mean EC₅₀ values for diluted ground water replicate samples were 20% and 18% respectively. This suggested that the P. fluorescens bioassay was as applicable to groundwater screening as the widely used Microtox bioassay.

A geochronologic framework for the Ziegler Reservoir fossil site, Snowmass Village, Colorado

The Ziegler Reservoir fossil site near Snowmass Village, Colorado, provides a unique opportunity to reconstruct high-altitude paleoenvironmental conditions in the Rocky Mountains during the last interglacial period. We used four different techniques to establish a chronological framework for the site. Radiocarbon dating of lake organics, bone collagen, and shell carbonate, and in situ cosmogenic Be and Al ages on a boulder on the crest of a moraine that impounded the lake suggest that the ages of the sediments that hosted the fossils are between ~ 140 ka and > 45 ka. Uranium-series ages of vertebrate remains generally fall within these bounds, but extremely low uranium concentrations and evidence of open-system behavior limit their utility. Optically stimulated luminescence (OSL) ages (n = 18) obtained from fine-grained quartz maintain stratigraphic order, were replicable, and provide reliable ages for the lake sediments. Analysis of the equivalent dose (D) dispersion of the OSL samples showed that the sediments were fully bleached prior to deposition and low scatter suggests that eolian processes were likely the dominant transport mechanism for fine-grained sediments into the lake. The resulting ages show that the fossil-bearing sediments span the latest part of marine isotope stage (MIS) 6, all of MIS 5 and MIS 4, and the earliest part of MIS 3.

MarcoPolo-R near earth asteroid sample return mission

MarcoPolo-R is a sample return mission to a primitive Near-Earth Asteroid (NEA) proposed in collaboration with NASA. It will rendezvous with a primitive NEA, scientifically characterize it at multiple scales,and return a unique sample to Earth unaltered by the atmospheric entry process or terrestrial weathering. MarcoPolo-R will return bulk samples (up to 2 kg) from an organic-rich binary asteroid to Earth for laboratory analyses, allowing us to: explore the origin of planetary materials and initial stages of habitable planet formation; identify and characterize the organics and volatiles in a primitive asteroid; understand the unique geomorphology, dynamics and evolution of a binaryNEA. This project is based on the previous Marco Polo mission study,which was selected for the Assessment Phase of the first round of Cosmic Vision. Its scientific rationale was highly ranked by ESA committees andit was not selected only because the estimated cost was higher than theallotted amount for an M class mission. The cost of Marco Polo-R will be reduced to within the ESA medium mission budget by collaboration withAPL (John Hopkins University) and JPL in the NASA program for coordination with ESA's Cosmic Vision Call. The baseline target is a binary asteroid (175706) 1996 FG3, which offers a very efficient operational and technical mission profile. A binary target also providesenhanced science return. The choice of this target will allow newinvestigations to be performed more easily than at a single object, andalso enables investigations of the fascinating geology and geophysics ofasteroids that are impossible at a single object. Several launch windows have been identified in the time-span 2020-2024. A number of otherpossible primitive single targets of high scientific interest have beenidentified covering a wide range of possible launch dates. The baselinemission scenario of Marco Polo-R to 1996 FG3 is as follows: a singleprimary spacecraft provided by ESA, carrying the Earth Re-entry Capsule, sample acquisition and transfer system provided by NASA, will be launched by a Soyuz-Fregat rocket from Kourou into GTO and using two space segment stages. Two similar missions with two launch windows, in 2021 and 2022 and for both sample return in 2029 (with mission durationof 7 and 8 years), have been defined. Earlier or later launches, in 2020 or 2024, also offer good opportunities. All manoeuvres are carried out by a chemical propulsion system. MarcoPolo-R takes advantage of three industrial studies completed as part of the previous Marco Polo mission (see ESA/SRE (2009)3, Marco Polo Yellow Book) and of the expertise of the consortium led by Dr. A.F. Cheng (PI of the NASA NEAR Shoemaker mission) of the JHU-APL, including JPL, NASA ARC, NASA LaRC, and MIT.

Comet C/2012 S1 (ISON): Observations of the Dust Grains from SOFIA and of the Atomic Gas from NSO Dunn and McMath-Pierce Solar Telescopes (Invited)

Comet C/2012 S1 (ISON) is unique in that it is a dynamically new comet derived from the Oort cloud reservoir of comets with a sun-grazing orbit. Infrared (IR) and visible wavelength observing campaigns were planned on NASA's Stratospheric Observatory For Infrared Astronomy (SOFIA) and on National Solar Observatory Dunn (DST) and McMath-Pierce Solar Telescopes, respectively. We highlight our early results. SOFIA (+FORCAST [1]) mid- to far-IR images and spectroscopy (~5-35 μm) of the dust in the coma of ISON are to be obtained by the ISON-SOFIA Team during a flight window 2013 Oct 21-23 UT (r_h≈1.18 AU). Dust characteristics, identified through the 10 μm silicate emission feature and its strength [2], as well as spectral features from cometary crystalline silicates (Forsterite) at 11.05-11.2 μm, and near 16, 19, 23.5, 27.5, and 33 μm are compared with other Oort cloud comets that span the range of small and/or highly porous grains (e.g., C/1995 O1 (Hale-Bopp) [3,4,5] and C/2001 Q4 (NEAT) [6]) to large and/or compact grains (e.g., C/2007 N4 (Lulin) [7] and C/2006 P1 (McNaught) [8]). Measurement of the crystalline peaks in contrast to the broad 10 and 20 μm amorphous silicate features yields the cometary silicate crystalline mass fraction [9], which is a benchmark for radial transport in our protoplanetary disk [10]. The central wavelength positions, relative intensities, and feature asymmetries for the crystalline peaks may constrain the shapes of the crystals [11]. Only SOFIA can look for cometary organics in the 5-8 μm region. Spatially resolved measurements of atoms and simple molecules from when comet ISON is near the Sun (r_h<0.4 AU, near Nov-20--Dec-03 UT) were proposed for by the ISON-DST Team. Comet ISON is the first comet since comet Ikeya-Seki (1965f) [12,13] suitable for studying the alkalai metals Na and K and the atoms specifically attributed to dust grains including Mg, Si, Fe, as well as Ca. DST's Horizontal Grating Spectrometer (HGS) measures 4 settings: Na I, K, C2 to sample cometary organics (along with Mg I), and [O I] as a proxy for activity from water [14] (along with Si I and Fe I). State-of-the-art instruments that will also be employed include IBIS [15], which is a Fabry-Perot spectral imaging system that concurrently measures lines of Na, K, Ca II, or Fe, and ROSA (CSUN/QUB) [16], which is a rapid imager that simultaneously monitors Ca II or CN. From McMath-Pierce, the Solar-Stellar Spectrograph also will target ISON (320-900 nm, R~21,000, r_h

Biosensor based toxicity dissection of tannery and associated environmental samples

Kenyan tannery and associated environmental samples were selected for ecotoxicological assessment. A tool-kit of techniques was developed, including whole-cell biosensor and chemical assays. A luminescence based bacterial biosensor (Escherichia coli HB101 pUCD607) (via a multi-copy plasmid) was used for toxicity assessment. Samples were manipulated prior to biosensor interrogation to identify the nature of the toxic contaminants. Untreated samples (before any manipulations) showed a strong toxic effect at the discharge point in comparison to other sampling points. Sparging was used to identify toxicity associated with volatile organics. The toxicity of contaminants, removed by treatment with activated charcoal was identified for all the sampling points except for those upstream of effluent discharges. Filtration identified toxicity associated with suspended solids. Changes in availability of toxic contaminants due to pH adjustment of most samples from the tannery effluent treatment pits were also associated with the extreme pH values (4.0 and 8.0). The approach used has highlighted the complexicity of toxic pollutants in effluent from the tanning industry and the dissection of toxicity points to possible remediation strategies for effluents from the tanning industry.

Comparison of granulometric methods and sampling strategies used in marine habitat classification and Ecological Status assessment

Sediment particle size analysis (PSA) is routinely used to support benthic macrofaunal community distribution data in habitat mapping and Ecological Status (ES) assessment. No optimal PSA Method to explain variability in multivariate macrofaunal distribution has been identified nor have the effects of changing sampling strategy been examined. Here, we use benthic macrofaunal and PSA grabs from two embayments in the south of Ireland. Four frequently used PSA Methods and two common sampling strategies are applied. A combination of laser particle sizing and wet/dry sieving without peroxide pre-treatment to remove organics was identified as the optimal Method for explaining macrofaunal distributions. ES classifications and EUNIS sediment classification were robust to changes in PSA Method. Fauna and PSA samples returned from the same grab sample significantly decreased macrofaunal variance explained by PSA and caused ES to be classified as lower. Employing the optimal PSA Method and sampling strategy will improve benthic monitoring. © 2012 Elsevier Ltd.