Treatment of poultry slaughterhouse wastewater in upflow anaerobic filter under low upflow velocity

The wastewater discharged by poultry slaughterhouse industries are characterized mainly by high biochemical oxygen demand, high suspended solids and complex mixture of fats, proteins and fibers requiring systematic treatment prior to disposal. In this study, the performance of an upflow anaerobic filter reactor for treating Indian poultry slaughterhouse wastewater under low upflow velocity of 1.38 m/day at mesophilic temperature (29-35 °C) was investigated. The reactor was inoculated with anaerobic non-granular sludge from an anaerobic reactor treating the poultry slaughterhouse wastewater. The reactor took 147 days for complete start-up with removal efficiencies of total chemical oxygen demand and soluble chemical oxygen demand of 70 and 79 % respectively. The maximum total chemical oxygen demand removal efficiency of 78 % was achieved at an organic loading rate of 10.05 kg/m³/day and at an hydraulic retention time of 12 h. The average methane content varied between 46 and 56 % and methane yield at maximum removal efficiency was 0.24 m³ CH₄/kg COD_removed·day. Sludge granules of 1–2 mm were observed in between the packing media. Scanning electron microscope analysis revealed that sludge granules are composed of clumps of Methanosarcina clustered with less intertwined Methanosaeta fibre of granules. The lower velocity used in this study has achieved better performance of the reactor by creating active microbial formation with stable pH upto an organic loading rate of 14.3 kg/m³/day. This has proved that the poultry slaughterhouse wastewater can be treated using anaerobic filter reactor under low upflow velocity.     

Microbial community analysis for aerobic granular sludge reactor treating high-level 4-chloroaniline wastewater

A laboratory-scale sequencing airlift bioreactor continuously treating high-level 4-chloroaniline (4-ClA) wastewater was used for studying the effect of 4-ClA on the characteristics and microbial community of aerobic granular sludge. The granulation of aerobic sludge and efficient pollutant removal performance were developed via shortening sludge settling time and gradually increasing influent 4-ClA concentration to around 400 mg L^?1. However, the granular sludge reactor deteriorated with the 4-ClA loading rate above 0.8 kg m^?3 d^?1. Denaturing gradient gel electrophoresis and real-time quantitative PCR were applied to investigate the microbial community succession during the start-up and recovery of bioreactor. The results showed that the performance of granular reactor was significantly influenced by the microbial community of aerobic granule, and stable aerobic granule was dominated with β-Proteobacteria (61.28 %), Flavobacteriales, Planctomycetales, Clostridiales, and Acidobacteria. Since Thauera (21.55 %) related to the genus β-Proteobacteria was abundant in the stable 4-ClA-degrading granular sludge, it was speculated as the main 4-ClA-degrading bacteria. Under high chloroaniline level, the sludge granulation may maintain the stability of the bioreactor via adjusting the composition of microbial community and abundance of functional microorganism. This paper provided useful information for better understanding the change of microbial community characteristics under high-level toxic organic pollutants and process optimizing.     

A novel pilot scale multistage semidry anaerobic digestion reactor to treat food waste and cow manure

An innovative two-stage AD system to treat food waste with cow manure is presented to address the problem of ammonia inhibition and improve the stability of methanogenic reactor. The liquid digestate recirculation in the first phase was adopted to enhance the hydrolysis rate and the solubilization of organic matter. A stable long-term run (80 days) was found. The reactor configuration and the digestate post-treatment with natural zeolite led to a low ammonia concentration in reactor outlet. The biogas production in the methanogenic reactor was very stable and high: The specific biogas production in the second phase was equal to 0.68–0.92 Nm³/kg_TVSadded and the average methane concentration was equal to 85%. Good performances were also found for the first-stage digestate, with 75% soluble COD removal efficiency. The high reactor performances were related to two-stage configuration, no ammonia and VFA inhibition.     

Evaluating the production and bio-stimulating effect of 5-methyl 1, hydroxy phenazine on microbial fuel cell performance

The role of endogenous redox mediators has considerable importance in electron shuttling reactions and associated performance of microbial fuel cell. Single-chamber microbial fuel cell-II with dual air-cathode assembly (area = 18.84 cm²) supported highest bacterial (Pseudomonas aeruginosa) density (6.7 × 10⁹) and active biomass [4.4 ± 0.3 mg cm^?2 (carbon content = 0.48 ± 0.1 mg cm^?2)] on anode thereby resulting in maximum production of redox metabolite, 5-methyl 1, hydroxy phenazine (301 ppm) and voltage (595 ± 5 mV) than similar cells with relatively less surface area of cathode. It was further revealed that 5-methyl 1, hydroxy phenazine production was positively correlated with chemical oxygen demand removal rate (77 ± 2.5%) and power generation (66.6 ± 2.2 mW cm^?2) efficiency of single-chamber microbial fuel cell-II. Maximum power density of 258 ± 4.5 mW cm^?2 was generated when reactor was supplemented with 2 ml crude extract of 5-methyl 1, hydroxy phenazine metabolite, whereas power output was about 229 ± 2.5 mW cm^?2 when reactor was bio-stimulated with 1 ml pure extract of 5-methyl 1, hydroxy phenazine. With this concentration, the electrochemical response of mixed culture biofilm (sediment) was enhanced by 99.3%. However, further increase in concentration of endogenous mediator proved to be limiting on reactor performance. Pyrosequencing and phylogenetic analysis on the basis of partial 16S rRNA sequences demonstrated both culturable and unculturable bacterial species in anodic biofilm and relative abundance of family Pseudomonadaceae was found to be maximum, i.e., 61.7% followed by Rhodocyclaceae 19.2%, Xanthomonadaceae 6.3% and Opitutaceae 3.18%.     

The dominant acetate degradation pathway/methanogenic composition in full-scale anaerobic digesters operating under different ammonia levels

Ammonia is a major environmental factor influencing biomethanation in full-scale anaerobic digesters. In this study, the effect of different ammonia levels on methanogenic pathways and methanogenic community composition of full-scale biogas plants was investigated. Eight full-scale digesters operating under different ammonia levels were sampled, and the residual biogas production was followed in fed-batch reactors. Acetate, labelled in the methyl group, was used to determine the methanogenic pathway by following the ¹⁴CH₄ and ¹⁴CO₂ production. Fluorescence in situ hybridisation was used to determine the methanogenic communities’ composition. Results obtained clearly demonstrated that syntrophic acetate oxidation coupled with hydrogenotrophic methanogenesis was the dominant pathway in all digesters with high ammonia levels (2.8–4.57 g NH₄ ⁺-N L^?1), while acetoclastic methanogenic pathway dominated at low ammonia (<1.21 g NH₄ ⁺-N L^?1). Thermophilic Methanomicrobiales spp. and mesophilic Methanobacteriales spp. were the most abundant methanogens at free ammonia concentrations above 0.44 g NH₃-N L^?1 and total ammonia concentrations above 2.8 g NH₄ ⁺-N L^?1, respectively. Meanwhile, in anaerobic digesters with low ammonia (<1.21 g NH₄ ⁺-N L^?1) and free ammonia (<0.07 g NH₃-N L^?1) levels, mesophilic and thermophilic Methanosaetaceae spp. were the most abundant methanogens.     

Impact of recent lake eutrophication on microbial community changes as revealed by high resolution lipid biomarkers in Rotsee (Switzerland)

The effects of eutrophication on short term changes in the microbial community were investigated using high resolution lipid biomarker and trace metal data for sediments from the eutrophic Lake Rotsee (Switzerland). The lake has been strongly influenced by sewage input since the 1850s and is an ideal site for studying an anthropogenically altered ecosystem. Historical remediation measures have had direct implications for productivity and microbial biota, leading to community composition changes and abundance shifts. The higher sewage and nutrient input resulted in a productivity increase, which led predominantly to a radiation in diatoms, primary producers and methanogens between about 1918 and 1921, but also affected all microorganism groups and macrophytes between about 1958 and 1972. Bacterial biomass increased in 1933, which may have been related to the construction of a mechanical sewage treatment plant. Biomarkers also allowed tracing of fossil organic matter/biodegraded oil contamination in the lake. Stephanodiscus parvus, Cyclotella radiosa and Asterionella formosa were the dominant sources of specific diatom biomarkers. Since the 1850s, the cell density of methanogenic Archaea (Methanosaeta spp.) ranged within ca. 0.5–1.8 × 10⁹ cells g⁻¹ dry sediment and the average lipid content of Rotsee Archaea was ca. 2.2 fg iGDGTs cell⁻¹. An altered BIT index (BIT_CH), indicating changes in terrestrial organic matter supply to the lake, is proposed.     

Do Spartina maritima Plantations Enhance the Macroinvertebrate Community in European Salt Marshes?

Ecological restoration of salt marshes using plantations may enhance the macroinvertebrate community, but little is known about the development of benthic macroinvertebrates after ecological engineering projects in European salt marshes. This study analyzed the environment and the macroinvertebrate community in European salt marshes 3 years after restoration using Spartina maritima plantations in comparison with non-restored and preserved marshes in Odiel Marshes (Southwest Iberian Peninsula). We hypothesized that planting Spartina maritima on intertidal mudflats would increase species richness and diversity (Shannon–Weaver index) of the benthic macroinvertebrate community by increasing environmental heterogeneity, providing feeding resources and improving sediments characteristics. Benthic macrofauna samples (composed mainly of annelids, crustaceans, and mollusks) were sampled in plots of 20 cm?×?25 cm to 5 cm depth between +1.8 and +3.0 m above Spanish Hydrographic Zero. Sediment organic matter content, bulk density, pH, and redox potential were the variables that best explained macroinvertebrate distribution. Restored marshes achieved similar diversity and even higher specific richness than preserved marshes, although with differences in species composition. Non-restored marshes showed the lowest diversity. Restored and preserved marshes did not differ in total abundance or biomass of macroinvertebrates, both being higher than in non-restored marshes. The macroinvertebrate communities in preserved and non-restored marshes showed the largest difference in taxa composition, with restored marshes occupying an intermediate position. Salt marsh restoration using S. maritima increased the complexity (ecological diversity and species richness) and abundance of the benthic macroinvertebrate community. Our study offers new information about the role of salt marsh plants in mediating faunal communities via ecological engineering projects.     

Comparison of fluid geochemistry and microbiology of multiple organic-rich reservoirs in the Illinois Basin, USA: Evidence for controls on methanogenesis and microbial transport

Microbial methane in sedimentary basins comprises approximately 20% of global natural gas resources, yet little is known about the environmental requirements and metabolic rates of these subsurface microbial communities. The Illinois Basin, located in the midcontinent of the United States, is an ideal location to investigate hydrogeochemical factors controlling methanogenesis as microbial methane accumulations occur: (1) in three organic-rich reservoirs of different geologic ages and organic matter types - Upper Devonian New Albany Shale (up to 900 m depth), Pennsylvanian coals (up to 600 m depth), and Quaternary glacial sediments (shallow aquifers); (2) across steep salinity gradients; and (3) with variable concentrations of . For all three organic-rich reservoirs aqueous geochemical conditions are favorable for microbial methanogenesis, with near neutral pH, concentrations <2 mM, and Cl⁻ concentrations <3 M. Also, carbon isotopic fractionation of CH₄, CO₂, and DIC is consistent with microbial methanogenesis, and increased carbon isotopic fractionation with average reservoir depth corresponds to a decrease of groundwater flushing rates with average depth of reservoir. Plots of stable isotopes of water and Cl⁻ show mixing between a brine endmember and freshwater, suggesting that meteoric groundwater recharge has affected all microbial methanogenic systems. Additionally, similar methanogenic communities are present in all three reservoirs with comparable cell counts (8.69E3-2.58E6 cells/mL). TRFLP results show low numbers of archaea species with only two dominant groups of base pairs in coals, shale, and limestone aquifers. These results compare favorably with other methanogen-containing deep subsurface environments. Individual hydrogeochemical parameters that have a Spearman correlation coefficient greater than 0.3 to variations in methanogenic species include stable isotopes of water (δ¹⁸O and δD), type of substrate (i.e. coals versus shale), pH, and Cl⁻ concentration. The matching of variations between methanogenic TRFLP data and conservative tracers suggests that deep circulation of meteoric waters influenced archaeal communities in the Illinois Basin. In addition, coalification and burial estimates suggest that in the study area, coals and shale reservoirs were previously sterilized (>80 °C in nutrient poor environments), necessitating the re-introduction of microbes into the subsurface via groundwater transport.     

Microbial communities in karst groundwater and their potential use for biomonitoring

The structure, diversity and dynamics of microbial communities from a swallow hole draining agricultural land and two connected karst springs (Switzerland) were studied using molecular microbiological methods and related to hydrological and physicochemical parameters. Storm responses and an annual hydrological cycle were monitored to determine the short- and long-term variability, respectively, of bacterial communities. Statistical analysis of bacterial genetic fingerprints (16S rDNA PCR-DGGE) of spring water samples revealed several clusters that corresponded well with different levels of the allochthonous swallow hole contribution. Microbial communities in spring water samples highly affected by the swallow hole showed low similarities among them, reflecting the high temporal variability of the bacterial communities infiltrating at the swallow hole. Conversely, high similarities among samples with low allochthonous contribution provided evidence for a stable autochthonous endokarst microbial community. Three spring samples, representative for low, medium and high swallow hole contribution, were analysed by cloning/sequencing in order to identify the major bacterial groups in the communities. The autochthonous endokarst microbial community was mainly characterized of δ-Proteobacteria, Acidobacteria and Nitrospira species. A high percentage of unknown sequences suggested further that many karst aquifer bacteria are still undiscovered. Finally, the potential use of groundwater biomonitoring using microbial communities is discussed.     

Simultaneous nitrification–denitrification of wastewater: effect of zeolite as a support in sequential batch reactor with step-feed strategy

One of the technologies used for wastewater nitrogen removal consists in simultaneous nitrification–denitrification. The low microbial growth rate and the low availability of organic material for the denitrification stage make it necessary to study new operational conditions and the use of microbial supports. The aim of this study was to evaluate the operational behavior of a simultaneous nitrification–denitrification process in a sequential batch reactor utilizing zeolite as a biomass support and step-feed strategy. Two reactors of 2 L were used, one with zeolite and another without zeolite, both operated at constant temperature (31 °C), varying nitrogen loading rate (NLR) from 0.041 to 0.113 kg total Kjeldahl nitrogen (TKN/m³/day). After 209 days, removals higher than 86 and 96 % in nitrogen compounds and organic matter were obtained, respectively. There was not accumulation of nitrate and nitrite in any case; this means that there was a simultaneous nitrification–denitrification in the reactors. The incorporation of zeolite in the system held higher concentration of biomass in the reactor; this led to reduce start-up to 21 days and to improve 11.31 % removal kinetic. The use of a step-feed strategy prevents events of inhibition by substrate, even duplicating tolerance to higher NLR for the same operation time.     

Tidal Habitats Support Large Numbers of Invasive Blue Catfish in a Chesapeake Bay Subestuary

The introduction of a non-native freshwater fish, blue catfish Ictalurus furcatus, in tributaries of Chesapeake Bay resulted in the establishment of fisheries and in the expansion of the population into brackish habitats. Blue catfish are an invasive species in the Chesapeake Bay region, and efforts are underway to limit their impacts on native communities. Key characteristics of the population (population size, survival rates) are unknown, but such knowledge is useful in understanding the impact of blue catfish in estuarine systems. We estimated population size and survival rates of blue catfish in tidal habitats of the James River subestuary. We tagged 34,252 blue catfish during July–August 2012 and 2013; information from live recaptures (n = 1177) and dead recoveries (n = 279) were used to estimate annual survival rates and population size using Barker’s Model in a Robust Design and allowing for heterogeneity in detection probabilities. The blue catfish population in the 12-km study area was estimated to be 1.6 million fish in 2013 (95% confidence interval [CI] adjusted for overdispersion: 926,307–2,914,208 fish). Annual apparent survival rate estimates were low: 0.16 (95% CI 0.10–0.24) in 2012–2013 and 0.44 (95% CI 0.31–0.58) in 2013–2014 and represent losses from the population through mortality, permanent emigration, or both. The tagged fish included individuals that were large enough to exhibit piscivory and represented size classes that are likely to colonize estuarine habitats. The large population size that we estimated was unexpected for a freshwater fish in tidal habitats and highlights the need to effectively manage such species.     

Stable carbon isotopic compositions of intact polar lipids reveal complex carbon flow patterns among hydrocarbon degrading microbial communities at the Chapopote asphalt volcano

Seepage of asphalt forms the basis of a cold seep system at 3000 m water depth at the Chapopote Knoll in the southern Gulf of Mexico. Anaerobic microbial communities are stimulated in the oil-impregnated sediments as evidenced by the presence of intact polar membrane lipids (IPLs) derived from archaea and Bacteria at depths up to 7 m below the seafloor. Detailed investigation of stable carbon isotope composition (δ¹³C) of alkyl and acyl moieties derived from a range of IPL precursors with distinct polar head groups resolved the complexity of carbon metabolisms and utilization of diverse carbon sources by uncultured microbial communities. In surface sediments most of the polar lipid-derived fatty acids with phosphatidylethanolamine (PE), phosphatidylglycerol (PG) and diphosphatidylglycerol (DPG) head groups could be tentatively assigned to autotrophic sulfate-reducing bacteria, with a relatively small proportion involved in the anaerobic oxidation of methane. Derivatives of phosphatidyl-(N)-methylethanolamine (PME) were abundant and could be predominantly assigned to heterotrophic oil-degrading bacteria. Archaeal IPLs with phosphate-based hydroxyarchaeols and diglycosidic glyceroldibiphytanylglyceroltetraethers (GDGTs) were assigned to methanotrophic archaea of the ANME-2 and ANME-1 cluster, respectively, whereas δ¹³C values of phosphate-based archaeols and mixed phosphate-based and diglycosidic GDGTs point to methanogenic archaea. At a 7 m deep sulfate-methane transition zone that is linked to the upward movement of gas-laden petroleum, a distinct increase in abundance of archaeal IPLs such as phosphate-based hydroxyarchaeols and diglycosidic archaeol and GDGTs is observed; their δ¹³C values are consistent with their origin from both methanotrophic and methanogenic archaea. This study reveals previously hidden, highly complex patterns in the carbon-flow of versatile microbial communities involved in the degradation of heavy oil including hydrocarbon gases that would not have been evident from classical compound-specific isotope analyses of either bulk IPL or apolar lipid derivatives.     

Treatment of septic tank effluent using moving-bed biological reactor: kinetic and biofilm morphology

Septic tanks are very commonly used wastewater collection systems throughout the world, and especially in rural areas. In this study, the use of moving-bed biological reactors (MBBR) for the treatment of septic tank effluent (STE) was examined. The study was conducted in two phases. In Phase I, the performance of septic tanks from four projects working under different operational conditions and with different service lives was followed to determine the parameters that required further treatment. In Phase II, four specially designed continuous flow pilot-plant MBBRs and one laboratory-scale batch reactor were tested for their efficiency in treating STE. Experiments were carried out at various temperatures (8–25 °C) and with different hydraulic retention times (HRTs). MBBR effectively reduced STE’s nutrients and chemical oxygen demand by 90 and 85 %, respectively, over 180 days of operation. The average ammonia removal rate at 25 °C increased from 0.279 to 0.540 kg N/m³ when the reactor HRT changed from 5.7 to 13.3 h. Under these conditions, the ammonia removal kinetics were successfully correlated with a theta model with an average θ value of 1.054. The biofilm morphology showed a stable and global biomass coverage (>70 %) and a high percentage of live cells. A thinner biofilm was observed when the MBBR operated at high temperatures. The results of this study showed that MBBR is a promising technology for post-treatment of septic tank effluent.     

Kinetics of urease mediated calcite precipitation and permeability reduction of porous media evidenced by magnetic resonance imaging

The enzyme urease drives the hydrolysis of urea leading to the release of ammonium ions and bicarbonate; in the presence of calcium, the rise in pH leads to increased calcium carbonate saturation and the subsequent precipitation of calcite. Although such alkalinizing ureolysis is widespread in nature, most studies have focussed on bacteria (i.e. indigenous communities or urease-active Sporosarcina pasteurii) for calcite precipitation technologies. In this study, urease-active jack bean meal (from the legume Canavalia ensiformis) was used to drive calcite precipitation. The rates of ureolysis (k _urea ), determined from measured NH₄ ⁺, enabled a direct comparison to microbial ureolysis rates reported in literature. It is also demonstrated that a simple single reaction model approach can simulate calcite precipitation very effectively (3–6 % normalised root-mean-square deviation). To investigate the reduction of permeability in porous media, jack bean meal (0.5 g L^?1) and solutions (400 mM urea and CaCl₂) were simultaneously pumped into a borosilicate bead column. One-dimensional magnetic resonance profiling techniques were used, non-invasively, for the first time to quantify the porosity changes following calcite precipitation. In addition, two-dimensional slice selective magnetic resonance images (resolution of ~0.5 × 1.0 mm) revealed that the exact location of calcite deposition was within the first 10 mm of the column. Column sacrifice and acid digestion also confirmed that 91.5 % of calcite was located within the first 14 mm of the column. These results have important implications for the design of future calcite precipitation technologies and present a possible alternative to the well known bacterial approaches.     

Response of sediment-dwelling annelida community in relation to geochemical parameters in the Gorgan Bay,Caspian Sea

This study aimed to investigate the population of annelida communities in relation to environmental factors and heavy metals accumulated in sediments of the Gorgan Bay. The pollution load index and potential ecological risk (PER) were calculated. The results indicated mean concentrations (ppm) of heavy metals were (mean ± SD) Pb: 11.5 ± 4.88, Cu: 18 ± 8.83, Zn: 42 ± 22.15, Ni: 29.20 ± 14.68, Co: 10.56 ± 14.68, As: 7.77 ± 2.12, Sr: 1,449 ± 902.59 and V: 26.64 ± 10.25. Considering PER, sediments of the Gorgan Bay had low ecological risk. Based on abundance data, dominant species were Streblospio gynobranchiata, Nereis diversicolor, Tubificoides fraseri and Tubificidae unknown, respectively. Results of redundancy analysis displayed that T. fraseri and N. diversicolor were associated with high values of Sr. All the species were negatively correlated with As. There were positive correlation between S. gynobranchiata and N. diversicolor with values of clay, salinity, depth and silt. The present study provided the relative importance of heavy metals and environmental variables which partly assist in structuring assemblages of annelida in a transitional area.     

Soil microbial community changes as a result of long-term exposure to a natural CO2 vent

The capture and geological storage of CO₂ can be used to reduce anthropogenic greenhouse gas emissions. To assess the environmental impact of potential CO₂ leakage from deep storage reservoirs on the abundance and functional diversity of microorganisms in near-surface terrestrial environments, a natural CO₂ vent (>90% CO₂ in the soil gas) was studied as an analogue. The microbial communities were investigated using lipid biomarkers combined with compound-specific stable carbon isotope analyses, the determination of microbial activities, and the use of quantitative polymerase chain reactions (Q-PCR). With this complementary set of methods, significant differences between the CO₂-rich vent and a reference site with a normal CO₂ concentration were detected. The δ¹³C values of the plant and microbial lipids within the CO₂ vent demonstrate that substantial amounts of geothermal CO₂ were incorporated into the microbial, plant, and soil carbon pools. Moreover, the numbers of Archaea and Bacteria were highest at the reference site and substantially lower at the CO₂ vent. Lipid biomarker analyses, Q-PCR, and the determination of microbial activities showed the presence of CO₂-utilising methanogenic Archaea, Geobacteraceae, and sulphate-reducing Bacteria (SRB) mainly at the CO₂ vent, only minor quantities were found at the reference site. Stable carbon isotopic analyses revealed that the methanogenic Archaea and SRB utilised the vent-derived CO₂ for assimilatory biosynthesis. Our results show a shift in the microbial community towards anaerobic and acidophilic microorganisms as a consequence of the long-term exposure of the soil environment to high CO₂ concentrations.     

Spatial heterogeneity of soil moisture, microbial biomass carbon and soil respiration at stand scale of an arid scrubland

Studying the influence of plants on soil biological variables in an arid zone is important to the understanding of soil processes and relationships between above and below ground. The objective of this study was to quantify the pattern and degree of soil heterogeneity for soil moisture and its relationship with microbial biomass carbon and soil respiration using geostatistical techniques at stand scale of an arid scrubland. The experiment was conducted in a scrubland landscape using a 2 × 2 m grid within a 16 × 14 m plot in the lower reach of Sangong River watershed in Xinjiang, northwest China. The results revealed the following: (1) Soil moisture and soil microbial biomass carbon had moderate spatial variation, but soil respiration had strong variation. Spatial variability of soil moisture in the study plot decreased when soil moisture changed from wet in April to dry in June. In addition, correlations of soil moisture with microbial biomass carbon and soil respiration were positive and significant (p < 0.005). (2) Variation of soil microbial biomass carbon and soil moisture had a strong spatial autocorrelation in the study plot, mainly induced by structural factors, and the spatial autocorrelation of microbial biomass carbon and soil respiration was mainly determined by soil moisture. (3) The location of the high-value positions of soil moisture, soil microbial biomass carbon and soil respiration were clearly around the positions of scrubs in the study plot. Such information provided some insights to explain the spatial heterogeneity of soil properties at stand scale in an arid region.     

Metal distributions in seawater,sediment and marine benthic macroalgae from the South Australian coastline

Algal species which are ubiquitous along the coastlines of many countries reflect the environmental conditions of the coastal seawater and may serve as useful biomonitors of anthropogenic pollution. Heavy metal concentrations of ten elements (As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) of potential environmental concern were determined in seawater, sediments and twelve species of benthic marine macroalgae from four locations (Glenelg, Port Adelaide, Port Broughton and Port Pirie) along the South Australian coastline. The four sites chosen represented varying degrees of metal contamination, where the capacity for benthic macroalgae to accumulate heavy metals from the environment was evaluated. Spatial differences in heavy metal concentration in both seawaters and sediments were observed at all sites with the highest concentrations of heavy metals including Cd (125 μg g^?1), Pb (2,425 μg g^?1) and Zn (7,974 μg g^?1) found in the finer sediment fractions (<250 μm) of Port Pirie. While all algal species studied (Acrosorium polyneurum, Anotrichium tenue, Cystophora Cephalornithos Cystophora monillifera, Cystophora monilliformis, Dictyopteris australis, Gelidium micropterum, Gracilaria, Hormophysa Cuneiformis, Sargassum cinctum, Scaberia agardhii and Ulva lactuca) accumulated metals to varying degrees, Blindigia marginata was a good biomonitor species for a number of metals including Cd, Co, Cr, Fe, Pb and Zn, exhibiting both relatively high total metal concentrations and significant concentration factors.     

Distribution of cadmium among multimedia in Lake Qinghai,China

Lake Qinghai in the Qinghai-Tibet plateau is the largest lake in China. This study firstly reported the geochemistry of Cd in the lake. Water samples were collected from Lake Qinghai (n = 69) and Buha River (n = 12), while sediment (n = 22) and topsoil (n = 45) samples were collected from the lake and around the lake area, respectively. In addition, pore water samples (n = 20) were separated from sediment samples. Water samples were analyzed for pH, K, Na, Ca, Mg, Cl, S, and Cd, while sediment and topsoil samples were analyzed for K, Na, Ca, Mg, Al, Fe, Mn, S, Sc, and Cd. The average concentration of Cd was 0.014 μg L^?1 in the water of Lake Qinghai and 0.007 μg L^?1 in the water of Buha River. However, the average concentration of Cd was 0.320 μg L^?1 in the sediment pore water, much higher than that in the lake water and river water. Cadmium concentration in the lake water might be mainly controlled by salinity, while it in the pore water might be mainly controlled by carbonate minerals. Cadmium concentration in the river water might be controlled by alkalinity and pH. The average concentration of Cd in the sediment was 0.284 mg kg^?1. The enrichment of Cd in the lake sediment was significantly higher than that in the topsoil around the lake. Anthropogenic atmospheric deposition of Cd did not led to the increase in dissolved Cd level in the lake water, but led to its enrichment in the lake sediment.     

Coral reefs as a tool for monitoring environmental and radiation hazards

Analysis of coral reef species enables characterization of the coral reefs and the degree to which human activities influence the reef composition. Geochemical characteristics, X-ray diffraction, and natural radionuclides analyses of four common coral reef species representing the branching and massive forms were conducted at the three areas under threat (Quseir Harbor, Safaga Harbor, and El-Esh area) along the Red Sea coast. Branching recorded higher carbonates and lower organic matter than the massive forms. Stylophora pistillata at Safaga Harbor and El-Esh area and Acropora humilis at Qusier Harbor recorded the highest carbonate percentages (96.88, 96.24, and 96.89%, respectively) meanwhile Platygyra daedalea at Safaga Harbor recorded the highest organic matter contents (5.07 and 4.91%). The highest Ca contents were observed in S. pistillata and Porites solida (65.87 and 64.87%), the highest Mg was in Acropora humilis and P. daedalea (1.06 and 0.88%) at Qusier Harbor, whilst the highest Sr was in S. pistillata and P. daedalea at Safaga Harbor. Then highest value of ²²⁶Ra recorded in A. humilis and P. solida (71 ± 3.5 Bq/kg and 63 ± 3.1 Bq/k) and ²³²Th in S. pistillata at El-Esh area may attribute to petroleum exploration activities. A. humilis and P. daedalea at Safaga Harbor recorded significant high ⁴⁰K values (505 ± 30 and 472 ± 13 Bq/kg, respectively) relative to the other localities. The low Ca and High Sr as well as the highest averages of ²³²Th and ⁴⁰K at Safaga Harbor indicated that the coral reef communities were highly affected by the terrestrial inputs from phosphate shipments.