bluuebunny/crossref_metadata_2025 huggingface dataset:
The contribution of Andreas Mayer for the natural history of the State of Paraná, Brazil: V. Reptiles: relevant addenda and corrigenda
Authors: Bérnils Renato Silveira , Moura-Leite Julio Cesar de
Published: April 2010

A study about the herpetological legacy of the German naturalist Andreas Mayer (1907-1986) (Bérnils & Moura-Leite, 1990) raised 83 specimens from 20 reptile species captured in the Brazilian states of Paraná and Mato Grosso do Sul (years 40, 50, and 60) and currently housed at the Museu de História Natural Capão da Imbuia (Curitiba). Just in Mayer's birth centenary, 15 more snakes collected by him and not presented in the former publication were founded. This material is relevant because (1) came from areas currently under human-altered environments; (2) was collected in areas that were poorly sampled at that time; and (3) embraced some species hard to find in Paraná, including the first occurrence of Phimophis cf. guerini for the state. Label data for the added snakes and some important corrections to the former article, with taxonomic and geographic updates, are being presented.
Design of a three-dimensional hand/forearm model to apply computational fluid dynamics
Authors: Marinho Daniel Almeida , Reis Victor Machado , Vilas-Boas João Paulo , Alves Francisco Bessone , Machado Leandro , Rouboa Abel Ilah , Silva António José
Published: April 2010

The purpose of this study was to develop a three-dimensional digital model of a human hand and forearm to apply Computational Fluid Dynamics to propulsion analysis in swimming. Computer tomography scans of the hand and forearm of an Olympic swimmer were applied. The data were converted, using image processing techniques, into relevant coordinate input, which could be used in Computational Fluid Dynamics software. From that analysis, it was possible to verify an almost perfect agreement between the true human segment and the digital model. This technique could be used as a means to overcome the difficulties in developing a true three-dimensional model of a specific segment of the human body. Additionally, it could be used to improve the use of Computational Fluid Dynamics generally in sports and specifically in swimming studies, decreasing the gap between the experimental and the computational data.
Biodegradation of erythrosin B dye by paramorphic Neurospora crassa 74A
Authors: Jesus Gisele Jane de , Corso Carlos Renato , Campos Adriana de , Franchetti Sandra Mara Martins
Published: April 2010

The present work used paramorphic forms of Neurospora crassa 74A to remove erythrosine. The fungus culture was grown in medium containing the dye, as only carbon source for 2 and 90 h of interaction. A washing process using distilled water isolated the cellular mass mycelia was dried for 12 h at 105ºC and transformed in fine powder and analyzed in FTIR. The supernatant was analyzed through spectrophotometer UV-Vis and FTIR. Significant differences in the spectrum of UV-VIS and FTIR were observed between the control and the supernatant and between wall control and the walls colored by red, in FTIR for 2 and 90 h. Some significant bands were modified, suggesting the possibility of enzymatic biodegradation in proportion to the time of contact between the dye and fungal biomass.
Catechol biodegradation kinetics using Candida parapsilopsis
Authors: Rigo Maurício , Alegre Ranulfo Monte , Bezerra José Raniere Mazile Vidal , Coelho Narjara , Bastos Reinaldo Gaspar
Published: April 2010

This study evaluated the biodegradation of catechol by a yeast strain of Candida parapsilopsis in standard medium in Erlenmeyer flasks. Results shown that the highest concentration of catechol caused the longer lag period, demonstrating that acclimatized cultures could completely degrade an initial catechol concentration of 910 mg/L within 48 h. Haldane's model validated the experimental data adequately for growth kinetics over the studied catechol concentration ranges of 36 to 910 mg/L. The constants obtained for this model were µmax = 0.246 h-1, Ks = 16.95 mg/L and Ki = 604.85 mg/L.
New aspects on atrazine biodegradation
Authors: Sene Luciane , Converti Attilio , Secchi Geslaine Aparecida Ribeiro , Simão Rita de Cássia Garcia
Published: April 2010

The world practice of using agrochemicals for long periods, in an indiscriminated and abusive way, has been a concern of the authorities involved in public health and sustainability of the natural resources, as a consequence of environmental contamination. Agrochemicals refer to a broad range of insecticides, fungicides and herbicides, and among them stands out atrazine, a herbicide intensively used in sugarcane, corn and sorghum cultures, among others. Researches have demonstrated that atrazine has toxic effects in algae, aquatic plants, aquatic insects, fishes and mammals. Due to the toxicity and persistence of atrazine in the environment, the search of microbial strains capable of degrading it is fundamental to the development of bioremediation processes, as corrective tools to solve the current problems of the irrational use of agrochemicals. This review relates the main microbial aspects and research on atrazine degradation by isolated microbial species and microbial consortia, as well as approaches on the development of techniques for microbial removal of atrazine in natural environments.
Manipulating Crop Row Orientation to Suppress Weeds and Increase Crop Yield
Authors: Borger Catherine P. D. , Hashem Abul , Pathan Shahab
Published: April 2010

Crop rows oriented at a right angle to sunlight direction (i.e., east–west within the winter cropping system in Western Australia) may suppress weed growth through greater shading of weeds in the interrow spaces. This was investigated in the districts of Merredin and Beverley, Western Australian (latitudes of 31° and 32°S) from 2002 to 2005 (four trials). Winter grain crops (wheat, barley, canola, lupines, and field peas) were sown in an east–west or north–south orientation. Within wheat and barley crops oriented east–west, weed biomass (averaged throughout all trials) was reduced by 51 and 37%, and grain yield increased by 24 and 26% (compared with crops oriented north–south). This reduction in weed biomass and increase in crop yield likely resulted from the increased light (photosynthetically active radiation) interception by crops oriented east–west (i.e., light interception by the crop canopy as opposed to the weed canopy was 28 and 18% greater in wheat and barley crops oriented east–west, compared with north–south crops). There was no consistent effect of crop row orientation in the canola, field pea, and lupine crops. It appears that manipulation of crop row orientation in wheat and barley is a useful weed-control technique that has few negative effects on the farming system (i.e., does not cost anything to implement and is more environmentally friendly than chemical weed control).
Rapid and Effective Methods for Breaking Seed Dormancy in Buffalobur (Solanum rostratum)
Authors: Wei Shouhui , Zhang Chaoxian , Chen Xuezheng , Li Xiangju , Sui Biaofeng , Huang Hongjuan , Cui Hailan , Liu Yan , Zhang Meng , Guo Feng
Published: April 2010

The spread of buffalobur in China poses a serious threat to existing ecosystems, and control and eradication of this species have become increasingly important. Studies were carried out to ascertain the seed production, morphological characterization, dormancy behavior, and methods for breaking dormancy of buffalobur. The results showed that a single buffalobur plant could produce 1,600 to 43,800 seeds with an average weight of 3.0 mg. Average seed length, width, and thickness were 2.5, 2.0, and 1.0 mm, respectively. Newly ripened buffalobur seeds were innately dormant and exhibited combinational dormancy, which involves a hard seed coat (physical dormancy, PY), a partial dormant embryo (physiological dormancy, PD), and a dark requirement to germinate. PY of buffalobur seeds could be broken by dehusking or acid scarification by 14 M H2SO4for 15 min, with germination rates of 55 or 50%, respectively. PD was effectively broken by KNO3or gibberellic acid (GA3). The optimum concentration for KNO3was between 20 and 40 mM, which resulted in over 70% seed germination. When presoaked with GA3at 30 C in dark for 24 h, maximum germination (> 98%) was obtained at 2.4 mM, the corresponding germination speed (85%) and germination index (16) were also highest at this concentration. Synergistic effects were observed in seed germination when H2SO4and GA3were combined. The most rapid and effective combination in breaking dormancy was when the seeds were immersed in H2SO4(14 M) for 20 min and presoaked with 2.4 mM GA3for 24 h. Germination index for this combination was over 35, and 95% of the seeds germinated within 7 d. Knowledge gained in this study will be useful in increasing germination of buffalobur and facilitating further laboratory studies.
Growth and Reproduction of Junglerice (Echinochloa colona) in Response to Water Stress
Authors: Chauhan Bhagirath S. , Johnson David E.
Published: April 2010

Junglerice is one of the most serious grass weeds of rice in the tropics. Greenhouse studies were conducted to evaluate growth and reproduction of junglerice in response to water stress. Plant height, biomass, and seed production of junglerice grown alone were reduced with increasing water stress. However, most stressed plants (irrigated at 12.5% of field capacity) still produced considerable biomass (8.5 g plant−1) and seeds (>1,600 seeds plant−1). When junglerice and rice were grown together under water-stressed condition, junglerice was taller than rice. The junglerice-to-rice biomass ratio also increased from 4.7 at 100% of field capacity to 7.6 at 12.5% of field capacity, indicating the greater junglerice vigor in water-stress conditions. In another study, the influence of the duration of water stress at intervals between 3 and 15 d on growth and seed production of junglerice was evaluated. Plant height, biomass, and seed production decreased with increasing water-stress duration. However, the weed produced an average of 400 seeds plant−1 in the most stressed treatment (i.e., when irrigation was applied at 15-d intervals). Water-stressed treatments did not affect germination of junglerice seeds in the laboratory. Growth and seed production of junglerice at all moisture levels ensures survival of the population in an unpredictable environment and contributes to the weedy nature of this species. The joint effect of enhanced weed competition and drought stress could severely harm crop yield; therefore, it is important to control such weeds in the early stages of crops and save stored moisture for the crops.
Growth, Phenology, and Intraspecific Competition between Glyphosate-Resistant and Glyphosate-Susceptible Horseweeds (Conyza canadensis) in the San Joaquin Valley of California
Authors: Shrestha Anil , Hanson Bradley D. , Fidelibus Matthew W. , Alcorta Marisa
Published: April 2010

Experiments were conducted in 2006 to 2008 to study growth, phenology, and competitive ability of glyphosate-resistant (GR) and -susceptible (GS) biotypes of horseweeds from San Joaquin Valley (SJV), CA. When grown alone, in pots, the GR horseweeds consistently developed more rapidly than the GS weeds, as evidenced by their earlier bolting, flowering, and seed set; the GR horseweeds set seeds nearly 25 d (approximately 190 fewer growing degree days) sooner than the GS horseweed. At seed set, the relatively slow-developing GS horseweeds had amassed 40% more shoot dry matter than the GR weeds at the same phenological stage, but neither biotype was consistently more fecund than the other. Although the GR biotype had lower shoot dry mass than the GS biotype when grown alone, in mixed populations under increasing levels of competition (in a replacement series design) and limited resources (mainly moisture), the GR weeds were not only taller, but also accumulated more dry matter than the GS weeds. Thus, the GR biotype was more competitive than the GS biotype, particularly when grown at high densities and under moisture-deficit stress. Therefore, under California conditions there is no apparent fitness penalty for this particular GR horseweed biotype, and it is likely to persist in the environment and outcompete the GS biotypes regardless of further glyphosate selection pressure. If so, this biotype of GR horseweed is likely to become increasingly common in the SJV until effective management strategies are developed and adopted.
Functional Genomics Analysis of Horseweed (Conyza canadensis) with Special Reference to the Evolution of Non–Target-Site Glyphosate Resistance
Authors: Yuan Joshua S. , Abercrombie Laura L. G. , Cao Yongwei , Halfhill Matthew D. , Zhou Xin , Peng Yanhui , Hu Jun , Rao Murali R. , Heck Gregory R. , Larosa Thomas J. , Sammons R. Douglas , Wang Xinwang , Ranjan Priya , Johnson Denita H. , Wadl Phillip A. , Scheffler Brian E. , Rinehart Timothy A. , Trigiano Robert N. , Stewart C. Neal
Published: April 2010

The evolution of glyphosate resistance in weedy species places an environmentally benign herbicide in peril. The first report of a dicot plant with evolved glyphosate resistance was horseweed, which occurred in 2001. Since then, several species have evolved glyphosate resistance and genomic information about nontarget resistance mechanisms in any of them ranges from none to little. Here, we report a study combining iGentifier transcriptome analysis, cDNA sequencing, and a heterologous microarray analysis to explore potential molecular and transcriptomic mechanisms of nontarget glyphosate resistance of horseweed. The results indicate that similar molecular mechanisms might exist for nontarget herbicide resistance across multiple resistant plants from different locations, even though resistance among these resistant plants likely evolved independently and available evidence suggests resistance has evolved at least four separate times. In addition, both the microarray and sequence analyses identified non–target-site resistance candidate genes for follow-on functional genomics analysis.
Absorption and Translocation of Glyphosate, Metsulfuron, and Triclopyr in Old World Climbing Fern (Lygodium microphyllum)
Authors: Hutchinson Jeffrey T. , Langeland Kenneth A. , MacDonald Gregory E. , Querns Robert
Published: April 2010

Old World climbing fern is one of the most invasive plants in natural areas of central and southern Florida. The fern spreads across the landscape by wind-blown spores and invades isolated and undisturbed habitats such as interior portions of the Florida Everglades. Land managers in Florida have reported that multiple herbicide treatments are required to control the fern, which could indicate that herbicides do not translocate throughout the plant in long-established populations. We conducted a greenhouse study to determine the absorption and translocation patterns in Old World climbing fern using the three herbicides most commonly used for management of this plant by land managers in Florida. Using14C-labeled herbicides, we evaluated absorption and translocation of glyphosate (2.25 kg ai ha−1), metsulfuron (0.10 kg ai ha−1), and triclopyr (1.68 kg ai ha−1) in Old World climbing fern using five different application scenarios (cut-and-spray, basal spray, 25% foliar spray, 50% foliar spray, and 100% foliar spray). Triclopyr was absorbed to the greatest extent (60.3%) of applied radioactive compounds compared to glyphosate (31.2%) and metsulfuron (19.8%). The majority of radioactivity remained in treated leaves for all herbicides with only small percentages of the absorbed radioactivity being detected in other plant parts. All three herbicides translocated acropetally and basipitally to some extent. Radioactivity, for the most part, translocated evenly throughout the plants but the greatest amount of radioactivity derived from triclopyr occurred in rhizomes when the cut-and-spray and basal applications were used. The radioactivity in rhizomes derived from glyphosate was greater in those treated using cut-and-spray. Based on autoradiographs, there was limited horizontal movement of any herbicide in the rhizomes of Old World climbing fern which could explain why resprouts are observed several weeks following treatment.
Time Requirement from Pollination to Seed Maturity in Waterhemp (Amaranthus tuberculatus)
Authors: Bell Michael S. , Tranel Patrick J.
Published: April 2010

Experiments were conducted to determine the amount of time required for waterhemp to produce mature seeds after pollination. Female waterhemp plants were pollinated over a 24-h time period and then isolated from males. Two branches, each containing at least 500 flowers, were harvested from each female at the time of the initial pollination, designated as 0 d after pollination (DAP), as well as at multiple other times after pollination up to 62 DAP. One branch from each harvest was stored at 30 C for 48 h, while the other branch was stored at −20 C for 48 h. Branches were then stored at room temperature until all harvests were complete, at which time seeds from each branch at each time after pollination were collected, weighed, and stratified. Germination tests were then conducted to determine the time at which seeds become viable after pollination. Seeds that had not germinated by the end of the germination tests were subjected to tetrazolium testing for viability. Germination tests were also conducted on nonstratified seeds to investigate changes in seed dormancy that were expected to occur over the amount of time the seeds were allowed to remain on the plants. Seeds stored initially at 30 C postharvest became viable 7 to 9 DAP, whereas seeds stored initially at −20 C postharvest did not become mature until 11 DAP. Seed coat color was white soon after pollination and became dark brown to nearly black by 12 DAP, and seed weight increased until 12 DAP. Tetrazolium tests for seed viability correlated well with the germination tests. Germination tests on nonstratified seeds indicated that dormancy level was initially high in the population used, but began to decrease between 15 and 30 DAP. Results of this study have implications both for waterhemp management and research.
Appearance of the pituitary factor Pit-1 increases chromatin remodeling at hypersensitive site III in the human GH locus
Authors: Yang Xiaoyang , Jin Yan , Cattini Peter A
Published: April 2010

Expression of pituitary and placental members of the human GH and chorionic somatomammotropin (CS) gene family is directed by an upstream remote locus control region (LCR). Pituitary-specific expression of GH requires direct binding of Pit-1 (listed as POU1F1 in the HUGO database) to sequences marked by a hypersensitive site (HS) region (HS I/II) 14.6 kb upstream of the GH-N gene (listed as GH1 in the HUGO database). We used human embryonic kidney 293 (HEK293) cells overexpressing wild-type and mutant Pit-1 proteins as a model system to gain insight into the mechanism by which Pit-1 gains access to the GH LCR. Addition of Pit-1 to these cells increased DNA accessibility at HS III, located 28 kb upstream of the human GH-N gene, in a POU homeodomain-dependent manner, as reflected by effects on histone hyperacetylation and RNA polymerase II activity. Direct binding of Pit-1 to HS III sequences is not supported. However, the potential for binding of ETS family members to this region has been demonstrated, and Pit-1 association with this ETS element in HS III sequences requires the POU homeodomain. Also, both ETS1 and ELK1 co-precipitate from human pituitary extracts using two independent sources of Pit-1 antibodies. Finally, overexpression of ELK1 or Pit-1 expression in HEK293 cells increased GH-N RNA levels. However, while ELK1 overexpression also stimulated placental CS RNA levels, the effect of Pit-1 appeared to correlate with ETS factor levels and target GH-N preferentially. These data are consistent with recruitment and an early role for Pit-1 in remodeling of the GH LCR at the constitutively open HS III through protein–protein interaction.
Climatic influence on demographic parameters of a tropical seabird varies with age and sex
Authors: Oro Daniel , Torres Roxana , Rodríguez Cristina , Drummond Hugh
Published: April 2010

In marine ecosystems climatic fluctuation and other physical variables greatly influence population dynamics, but differential effects of physical variables on the demographic parameters of the two sexes and different age classes are largely unexplored. We analyzed the effects of climate on the survival and recruitment of both sexes and several age classes of a long‐lived tropical seabird, the Blue‐footed Booby (Sula nebouxii), using long‐term observations on marked individuals. Results demonstrated a complex interaction between yearly fluctuations in climate (both local and global indexes, during both winter and breeding season) and the sex and age of individuals. Youngest birds' survival and recruitment were commonly affected by local climate, whereas oldest birds' parameters tended to be constant and less influenced by environmental variables. These results confirm the theoretical prediction that sex‐ and age‐related variation in life‐history demographic traits is greater under poor environmental conditions, and they highlight the importance of including variability in fitness components in demographic and evolutionary models. Males and females showed similar variation in survival but different recruitment patterns, in relation to both age and the spatial scale of climatic influence (local or global). Results indicate different life‐history tactics for each sex and different ages, with birds likely trying to maximize their fitness by responding to the environmental contingencies of each year.
Probabilistic risk evaluation for triclosan in surface water, sediments, and aquatic biota tissues
Authors: Lyndall Jennifer , Fuchsman Phyllis , Bock Michael , Barber Timothy , Lauren Darrel , Leigh Katrina , Perruchon Elyse , Capdevielle Marie
Published: April 2010

Triclosan, an antimicrobial compound used in personal care products, occurs in the aquatic environment due to residual concentrations in municipal wastewater treatment effluent. We evaluate triclosan-related risks to the aquatic environment, for aquatic and sediment-dwelling organisms and for aquatic-feeding wildlife, based on measured and modeled exposure concentrations. Triclosan concentrations in surface water, sediment, and biota tissue are predicted using a fugacity model parameterized to run probabilistically, to supplement the limited available measurements of triclosan in sediment and tissue. Aquatic toxicity is evaluated based on a species sensitivity distribution, which is extrapolated to sediment and tissues assuming equilibrium partitioning. A probabilistic wildlife exposure model is also used, and estimated doses are compared with wildlife toxicity benchmarks identified from a review of published and proprietary studies. The 95th percentiles of measured and modeled triclosan concentrations in surface water, sediment, and biota tissues are consistently below the 5th percentile of the respective species sensitivity distributions, indicating that, under most scenarios, adverse affects due to triclosan are unlikely. Integr Environ Assess Manag 2010;6:419–440. © 2010 SETAC
Living in Utility Scarcity: Energy and Water Insecurity in Northwest Alaska
Authors: Eichelberger Laura Palen
Published: April 2010

This study explored the links between energy and water insecurity in rural Iñupiaq Eskimo villages in Alaska's Northwest Arctic Borough. High energy costs and the need for fuel-based transportation are 2 significant factors in domestic water access for these communities. Dramatic increases in the costs of energy have led to decreased domestic water access, with adverse effects on household hygiene practices. I traced the ways in which the high costs of energy determine water consumption from production to household acquisition and use. Improving sanitation and access to domestic water requires considering the water–energy nexus: the amount and cost of energy required to treat and distribute water as well as manage waste. I use the term utility scarcity to underscore the relationship between domestic water, energy, and health.
Using an Event-Triggered Video Intervention System to Expand the Supervised Learning of Newly Licensed Adolescent Drivers
Authors: Carney Cher , McGehee Daniel V. , Lee John D. , Reyes Michelle L. , Raby Mireille
Published: April 2010

Objectives. We examined whether feedback from an event-triggered video intervention system reduced the number of safety-relevant driving errors made by newly licensed adolescents.

Methods. We used a 1-group pretest–posttest quasi-experimental design to compare the rate of coachable error events per 1000 miles for 18 drivers who were aged 16 years. The intervention consisted of immediate visual feedback provided to the drivers and weekly event reports and videos provided to the drivers and their parents.

Results. The number of coachable events was reduced by 61% overall during the intervention (χ2= 11.42; P = .001) and did not significantly increase during the second baseline, which was assessed after the intervention ended (χ2= 1.49; P = .223). The greatest reduction was seen in the category of improper turns or curves and for drivers identified at the first baseline as “high-event” drivers.

Conclusions. Our results show that immediate visual feedback for adolescents and cumulative video feedback for parents and adolescents during the early period of independent driving can have a dramatic influence on the rate of safety-relevant driving events. To the extent that such events are a proxy for crash risk, we suggest that feedback can enhance adolescent driving safety.
Investigation of the solution initial pH effects on the performance of UV/Fe-ZSM5/H2O2 process
Authors: Kasiri M. B. , Aleboyeh A. , Aleboyeh H.
Published: April 2010

Effect of the solution initial pH was investigated on the performance of photo-Fenton process using Fe-ZSM5 zeolite as a heterogeneous catalyst for degradation of azo dye Acid Red 14. All experiments were performed in a 1.0 L tubular closed circulation batch photo-reactor. The dye degradation quantum yield was maximal when the solution initial pH was about 5. An amount of about 0.3 mg L−1 of Fe ions leached out of the zeolite. However, monitoring Fe ion concentration during the experiments showed that the efficiency of the process is not due to the leached Fe ions. The effect of pH on decomposition rate of hydrogen peroxide in different systems such as H2O2 alone, UV/H2O2, UV/Zeolite and UV/Zeolite/H2O2 was explored in detail to explain the results obtained.
Determination of water quality index by fuzzy logic approach: a case of ground water in an Indian town
Authors: Jinturkar A. M. , Deshmukh S. S. , Agarkar S. V. , Chavhan G. R.
Published: April 2010

The paper proposes fuzzy logic model that deals with the physico-chemical water analysis of ground water of Chikhli town for determination of Water Quality Index (WQI). The study was carried by collection of ground water samples from about eleven hand pumps located in this town. Ground water quality is studied by systematic collection and analysis of samples. The fuzzy logic is used for the deciding the water quality index on the basis of which, water quality rankings are given to determine the quality of water. The Water Quality Index presented here is a unitless number ranging from 1 to 10. A higher number is indicative of better water quality. Around 81% of samples were found suitable for drinking purpose. It is also observed that all the parameters fall within the permissible limits laid by WHO, ISI, and ICMR, except Total Hardness, Calcium and Magnesium. The quality parameters were compared with standards laid by the World Health Organization (WHO), Indian Standards Institute (ISI) and Indian Council of Medical Research (ICMR) for drinking water quality.
Behaviour and adsorptive removal of siloxanes in sewage sludge biogas
Authors: Oshita K. , Ishihara Y. , Takaoka M. , Takeda N. , Matsumoto T. , Morisawa S. , Kitayama A.
Published: April 2010

We investigated the behaviour of siloxanes, which adversely affect biogas engines, as well as their concentration levels in sewage sludge biogas in Japan. We also performed experiments on the absorptive removal of siloxanes using various adsorbents and determined the main adsorbent characteristics required for the removal of siloxanes. The results of our study on the concentration and composition of siloxanes in biogas were similar to previous reports. Moreover, we found that the concentration of siloxanes changes in relation to the outside air temperature based on real-time measurements of siloxanes using a continuous analyser. We further speculated that the continuous analyser would accurately indicate the siloxane concentration in model biogas but overestimate the siloxane concentration in actual biogas because of positive interference by VOCs and other biogas components. In the siloxane adsorption experiment, the equilibrium uptake of both cyclic siloxanes, D4 and D5, was positively related to the BET-specific surface area of the adsorbents and the fraction of the external surface area taken up by relatively large diameter pores. We attributed the adsorption results to the fact that the siloxane molecules are generally larger than micropores; therefore, they are less susceptible to adsorption to micropores. Based on these results, we concluded that adsorbents with large BET-specific surface areas, especially those with a high external specific surface area and pores of relatively large diameters, are desired for the removal of siloxanes.
Desalination of brackish groundwater by direct contact membrane distillation
Authors: Hou D. Y. , Wang J. , Qu D. , Luan Z. K. , Zhao C. W. , Ren X. J.
Published: April 2010

The direct contact membrane distillation (DCMD) applied for desalination of brackish groundwater with self-made polyvinylidene fluoride (PVDF) membranes was presented in the paper. The PVDF membrane exhibited high rejection of non-volatile inorganic salt solutes and a maximum permeate flux 24.5 kg m−2 h−1 was obtained with feed temperature at 70°C. The DCMD experimental results indicated that the feed concentration had no significant influence on the permeate flux and the rejection of solute. When natural groundwater was used directly as the feed, the precipitation of CaCO3 would be formed and clog the hollow fibre inlets with gradual concentration of the feed, which resulted in a rapid decline of the module efficiency. The negative influence of scaling could be eliminated by acidification of the feed. Finally, a 250 h DCMD continuous desalination experiment of acidified groundwater with the concentration factor at constant 4.0 was carried out. The permeate flux kept stable and the permeate conductivity was less than 7.0 μS cm−1 during this process. Furthermore, there was no deposit observed on the membrane surface. All of these demonstrated that DCMD could be efficiently used for production of high-quality potable water from brackish groundwater with water recovery as high as 75%.
An experimental study on the effect of spacer on concentration polarization in a long channel reverse osmosis membrane cell
Authors: Mo H. , Ng H. Y.
Published: April 2010

This study was to experimentally investigate the performance and organic fouling behaviour in a 1-m long RO membrane channel with or without spacer for desalting. It was found that local permeate flux distributed heterogeneously along the long membrane channel without a spacer inserted due to exponential growth of concentration polarization, which also resulted in decreasing salt rejection and increasing organic fouling along the membrane channel in the downstream direction. This heterogeneity could be lessened by inserting a spacer into the channel, which mitigated concentration polarization due to the enhanced turbulence caused by a spacer, especially at the downstream portion of the channel. However, in the upstream of the channel, inserting a spacer exerted an additional vertical resistance which might counteract the effect of concentration polarization mitigation by a spacer and caused a lower permeate flux. This suggests that it is necessary to consider the integral effect of spacer for designing an RO membrane module and an overall RO system in order to prevent extra resistance, reduce concentration polarization and membrane fouling.
Surface hydrophilisation and antibacterial functionalisation for microporous polypropylene membranes
Authors: Yang Y. F. , Wan L. S. , Xu Z. K.
Published: April 2010

The surface properties of polymer membranes are crucial to their separation performances. For the microporous polypropylene membranes, the high hydrophobicity and lack of functionality easily cause protein adsorption and subsequent microorganism attachment and biofilm formation, i.e. biofouling. Thus, their applications in water treatment, bioseparation and biomedical fields are largely limited. Surface hydrophilisation and antibacterial functionalisation are, therefore, reasonably necessary. This review provides a concise summarisation of related studies according to the surface modification strategies. Especially, the interfacial crosslinking approach developed in our previous studies is presented in detail.
Electrochemical degradation of PAH compounds in process water: a kinetic study on model solutions and a proof of concept study on runoff water from harbour sediment purification
Authors: Muff J. , Søgaard E. G.
Published: April 2010

The present study has investigated the possibility to apply electrochemical oxidation in the treatment of polycyclic aromatic hydrocarbon (PAHs) pollutants in water. The reaction kinetics of naphthalene, fluoranthene, and pyrene oxidation have been studied in a batch recirculation experimental setup applying a commercial one-compartment cell of tubular design with Ti/Pt90-Ir10 anode. The rate of oxidation has been evaluated upon variations in current density, electrolyte composition and concentration. All three PAHs were degraded by direct anodic oxidation in 0.10 M Na2SO4 electrolyte, and the removal rates were significantly enhanced by a factor of two to six in 0.10 M NaCl due to contribution from the indirect hypochlorite oxidation. Second order reaction kinetics was observed for the degradation of naphthalene in all electrolytes whereas fluoranthene and pyrene followed first order kinetics. Decreased current densities from 200 to 15 mA cm−2 in the NaCl electrolyte also decreased the removal rates, but significantly enhanced the current efficiencies of the PAH oxidation, based on a defined current efficiency constant, kq. This observation is believed to be due to the suppression of the water oxidation side reaction at lower applied voltages. A proof of concept study in real polluted water demonstrated the applicability of the electrochemical oxidation technique for larger scale use, where especially the indirect chloride mediated oxidation approach was a promising technique. However, the risk and extent of by-product formation needs to be studied in greater detail.
Urban flooding: one-dimensional modelling of the distribution of the discharges through cross-road intersections accounting for energy losses
Authors: Lipeme Kouyi G. , Rivière N. , Vidalat V. , Becquet A. , Chocat B. , Guinot V.
Published: April 2010

Many investigations have been carried out in order to develop models which allow the understanding of complex physical processes involved in urban flooding. The modelling of the interactions between overland flows on streets and flooding flows from rivers and sewer networks is one of the main objectives of recent and current research programs in hydraulics and urban hydrology. However, the modelling of the discharge distribution in the street network with crossroad needs further research due to the complexity of the flow through junctions. This paper outlines the ability of the improved one-dimensional CANOE software to simulate the street flows through the virtual network (developed under the Hy2Ville French National project framework) with several cross-roads. The improvements are done by adding in CANOE the energy losses coefficients deriving from the calibration phase based on the experimental study of the flow through small scale physical model of cross-road channels. Comparisons between 1D and 2D simulated distribution of discharges through the virtual network show a good agreement for the global distribution. However, large differences are observed focusing on the individual cross-road intersections in the virtual network.
The use of deconvolution techniques to identify the fundamental mixing characteristics of urban drainage structures
Authors: Stovin V. R. , Guymer I. , Chappell M. J. , Hattersley J. G.
Published: April 2010

Mixing and dispersion processes affect the timing and concentration of contaminants transported within urban drainage systems. Hence, methods of characterising the mixing effects of specific hydraulic structures are of interest to drainage network modellers. Previous research, focusing on surcharged manholes, utilised the first-order Advection-Dispersion Equation (ADE) and Aggregated Dead Zone (ADZ) models to characterise dispersion. However, although systematic variations in travel time as a function of discharge and surcharge depth have been identified, the first order ADE and ADZ models do not provide particularly good fits to observed manhole data, which means that the derived parameter values are not independent of the upstream temporal concentration profile. An alternative, more robust, approach utilises the system's Cumulative Residence Time Distribution (CRTD), and the solute transport characteristics of a surcharged manhole have been shown to be characterised by just two dimensionless CRTDs, one for pre- and the other for post-threshold surcharge depths. Although CRTDs corresponding to instantaneous upstream injections can easily be generated using Computational Fluid Dynamics (CFD) models, the identification of CRTD characteristics from non-instantaneous and noisy laboratory data sets has been hampered by practical difficulties. This paper shows how a deconvolution approach derived from systems theory may be applied to identify the CRTDs associated with urban drainage structures.
Recycling of spent filter backwash water using coagulation-assisted membrane filtration: effects of submicrometre particles on membrane flux
Authors: Huang Chihpin , Lin Jr-Lin , Wu C. L. , Chu C. P.
Published: April 2010

Membrane separation technology has been widely used for recycling of spent filter backwash water (SFBW) in water treatment plant. Membrane filtration performance is subject to characteristics of the particles in the SFBW. A bench-scale microfiltration (MF) coupled with pre-coagulation was set up to evaluate the recovery efficiency of SFBW. Effect of particle size distribution and zeta potential of the coagulated SFBW on the membrane filtration as well as the coagulation strategies were investigated. Pore clogging was more severe on the membrane with 1.0 μm pore size than on the membrane with 0.5 μm pore size due to the fact that submicrometre particles are dominant and their diameters are exactly closed to the pore size of the MF membrane. Pre-settling induced more severe irreversible fouling because only the submicrometre particles in the water become predominant after settling, resulting in the occurrence of more acute pore blocking of membrane. By contrast, pre-coagulation mitigates membrane fouling and improves membrane flux via enlarging particle size on membrane surface. The variations of zeta potential in response to coagulant dosing as well as fractal dimension were also compared with the performance of the subsequent filtration. The result showed that pre-coagulation induced by charge neutralization at the optimum dosage where the zeta potential is around zero leads to the optimal performance of the subsequent membrane filtration for SFBW recycling. At such condition, the fractal dimension of coagulated flocs reached minimum.
CWPO of 4-CP and industrial wastewater with Al–Fe pillared clays
Authors: Molina C. B. , Zazo J. A. , Casas J. A. , Rodriguez J. J.
Published: April 2010

Catalysts based on pillared clays with Al–Fe have been synthesised from a commercial bentonite and tested for catalytic wet peroxide oxidation (CWPO) of aqueous 4-Chlorophenol (4-CP) solution and industrial wastewater from cosmetics manufacture. The effect of the synthesis procedure, the iron load and reaction temperature on the catalytic activity was studied using 4-CP as target compound. A lower temperature in the preparation of the pillaring solution, as well as a higher Fe load, gave rise to a higher catalytic activity, but also a higher leaching of the active phase. The best catalyst, in terms of catalytic activity, was also tested for treating cosmetic wastewater by CWPO. Experiments were carried out at 90°C and atmospheric pressure and the influence of Fe load, catalyst concentration and H2O2/COD ratio (between 0.5 and 2 times the stoichiometric ratio) were analysed. Higher values of these parameters favour COD reduction. The Fe leaching in all cases was lower than 1.2 mg/L, indicating that these catalysts have a high stability under these experimental conditions.
Catalytic oxidation and spectroscopic analysis of simulated wastewater containing acid chrome blue K by using chlorine dioxide as oxidant
Authors: Yu Fengjun , Shi Laishun
Published: April 2010

An activated carbon-MnO2 catalyst was prepared by the dipping-calcination method using activated carbon as catalyst support. The catalyst was used for the catalytic oxidation of simulated acid chrome blue K wastewater. The COD removal efficiency and decolor efficiency by catalytic oxidation are 72.0% and 87.8%, respectively, at the condition of wastewater's COD is 2,418 mg/L, the optimum pH value is 1.2, the dosage of chlorine dioxide is 1,200 mg/L, the dosage of activated carbon-MnO2 catalyst is 4 g by reacting 50 min. The COD removal efficiency by catalytic oxidation is great than that of chemical oxidation. The COD removal efficiency only decreased a little after the catalyst used 8 times. The FTIR spectra indicate that the active ingredient of manganese dioxide is linked with activated carbon by chemical bond, not merely mechanical blending. The intermediates during the degradation process were obtained by using online infrared spectrum analysis. The degradation reaction mechanism of acid chrome blue K by chlorine dioxide oxidation was proposed based upon the experiment evidence.
Evaluation of chitosan as a natural coagulant for drinking water treatment
Authors: Fabris R. , Chow C. W. K. , Drikas M.
Published: April 2010

Chitosan, a natural biopolymer, was evaluated for its ability to be used as a coagulant to treat water for potable use both in isolation and in combination with other water treatment technologies, specifically ion-exchange and activated carbon. Chitosan was found to be very effective for particle removal at doses far below those required for equivalent turbidity removal by inorganic coagulants. However in the water sources tested, chitosan was not particularly efficient for dissolved organic carbon (DOC) removal when applied as the sole treatment step. When applied as the final clarification stage of a multi-step treatment process, chitosan exhibited limited turbidity reduction due to specific flocculation requirements. This combination of treatment technologies was also unable to further reduce secondary water quality parameters, such as disinfectant demand and trihalomethane (THM) formation.
Combining partial nitritation and heterotrophic denitritation for the treatment of landfill leachate previous to an anammox reactor
Authors: Ganigué R. , Gabarró J. , López H. , Ruscalleda M. , Balaguer M. D. , Colprim J.
Published: April 2010

Landfill leachate can present extremely elevated concentrations of ammonium (up to 6,000 mg N-NH4+ L−1) and a low biodegradable organic matter fraction. As an alternative to conventional systems, this wastewater can be treated on a more sustainable way by a fully autotrophic partial nitritation–anammox system. The operation of the first step of this system, the partial nitritation, is critical since the elevated concentrations of ammonium and nitrite in the reactor can severely inhibit ammonium oxidizing bacteria (AOB) activity. In this way, the inclusion of anoxic phases during the feeding events to promote the denitrification via nitrite can be a good option for upgrading the process performance and increasing the stability of the system. This paper deals with the evaluation of an anoxic–aerobic step-feed strategy for the operation of a partial nitritation SBR. Results of this study have revealed a decrease on the total nitrogen inside the reactor of more than 200 mg N L−1 without prejudice on the partial nitritation process. Furthermore, this study has also allowed detecting an AOB activity reduction at the end of aerobic phases due to bicarbonate limitation and/or free nitrous acid inhibition.
Syntrophy of aerobic and anaerobic ammonia oxidisers
Authors: Wett B. , Hell M. , Nyhuis G. , Puempel T. , Takacs I. , Murthy S.
Published: April 2010

Deammonification is known as an efficient and resource saving sidestream process option to remove the nitrogen load from sludge liquors. The transfer of the intermediate product nitrite between both syntrophic groups of organisms – aerobic and anaerobic ammonia oxidizers (AOB) – appears very sensitive to process conditions such as temperature, dissolved oxygen (DO) and operating nitrite level. Growth kinetics for aerobic and anaerobic AOBs differ by one order of magnitude and require an adequate selection of sludge retention time. This paper provides measurement- and model-based results on how selected sludge wasting impacts population dynamics in a suspended growth deammonification system. Anammox enrichment up to a doubled portion in mixed liquor solids can substantially improve process stability in difficult conditions. A case-study on low temperature operations outlines two possible strategies to balance syntrophic consumption of ammonium and nitrite.
Impact of ionic strength on adsorption capacity of chromatographic particles employed in separation of monoclonal antibodies
Authors: Wrzosek Katarzyna , Gramblička Michal , Tóthová Darina , Antošová Monika , Polakovič Milan
Published: April 2010

The influence of ionic strength on the adsorption capacity of seven commercial adsorbents used in downstream processing of monoclonal antibodies was examined. Affinity (MabSelect, Poros 50A High Capacity, ProSep-vA High Capacity), hydrophobic charge-induction (MEP HyperCel), and cation exchange adsorbents (FractoGel EMD SE Hicap (M), SP Sepharose Fast Flow, Ceramic HyperD F) were used to study the adsorption of polyclonal human immunoglobulin G at optimal pH values. The ionic strength, adjusted by sodium chloride concentrations in the range of 0–225 mM, strongly decreased the adsorption capacity of the cation exchangers. Equilibrium data were described in the form of the dependence of the ratio of protein concentrations in the solid and liquid phases on the total concentration of cation counter ions. They were successfully fitted and interpreted through a stoichiometric ion-exchange model.
Vibrational spectroscopic and conformational studies of 1-(4-pyridyl)piperazine
Authors: Alver Özgür , Şenyel Mustafa
Published: April 2010

Possible stable conformers of the 1-(4-pyridyl)piperazine (1-4pypp) molecule were experimentally and theoretically studied by FT-IR and Raman spectroscopy. FT-IR and Raman spectra were recorded in the region of 4000–200 cm−1. Optimized geometric structures related to the minimum on the potential energy surface were investigated by the B3LYP hybrid density functional theory method using the 6-31G(d) basis set. Comparison of the experimental and theoretical results indicates that the density functional B3LYP method provides satisfactory results for the prediction of vibrational wavenumbers and structural parameters and equatorial-equatorial (e-e) isomer is supposed to be the most stable form of the 1–4pypp molecule.