BACKGROUND: Lotus root beverage is commonly made from raw lotus root (RLR). However, RLR production is strictly limited, because it is prone to decomposition and browning after its short harvest season. In this study an innovative beverage was prepared from full lotus root powder (FLRP) as a substitute for RLR in an attempt to solve this problem.RESULTS: The components of FLRP basically corresponded to those of RLR, but there was some loss of heat-labile compounds. Using differential scanning calorimetry, a gelatinisation temperature range of 57.08-67.80 degrees C was determined for FLRP with an average particle size distribution of 70 microm. The optimal conditions for enzymatic treatment of FLRP beverage were determined by response surface methodology as an enzyme concentration of 2.2 g kg(-1) at 53 degrees C for 86 min. Turbidity decreased from 1082 to 280 nephelometric turbidity units following enzymolysis. Properties of FLRP beverage were also studied and a qualitative comparison of flavour compounds between RLR and FLRP beverages was made by electronic nose.CONCLUSION: Basic flavour compounds were consistent and flavour radar plots had approximately the same shape, area and proportion when all ingredients were identical apart from FLRP and RLR. Therefore, in terms of flavour, FLRP beverage appears to be a feasible substitute for RLR beverage. Copyright (c) 2010 Society of Chemical Industry.

The bacterial community in a partial nitrification reactor was analyzed on the basis of 16S rRNA gene by cloning-sequencing method, and the percentages of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) in the activated sludge were quantified by three independent methods, namely, denaturing gradient gel electrophoresis (DGGE), terminal restriction fragment length polymorphism (T-RFLP) and Double Monod modeling. The clone library results suggested that there were only a dominant AOB and a dominant NOB species in the reactor, belonging to Nitrosomonas genus and Nitrospira genus, respectively. The percentages of NOB in total bacterial community increased from almost 0% to 30% when dissolved oxygen (DO) levels were changed from 0.15 mg/L to 0.5 mg/L, coinciding with the accumulation and conversion of nitrite, while the percentages of AOB changed little in the two phases. The results confirmed the importance of low DO level for inhibiting NOB to achieve partial nitrification. Furthermore, the percentages of AOB and NOB in the total bacteria community were estimated based on the results of batch experiments using Double Monod model, and the results were comparable with those determined according to profiles of DGGE and T-RFLP.

Increasing anthropogenic influence on lotic environments as a result of civilisation has captured public interest because of the consequent problems associated with deterioration of water quality. Various biological monitoring methods that provide a direct measure of ecological integrity by using the response of biota to environmental changes have been developed to monitor the ecological status of lotic environments. Diatoms have been used extensively in this regard and this review attempts to summarise the basic concepts associated with biological monitoring using benthic diatoms. Where possible, examples from work carried out in Brazil are used.

Abstract Objective: Adequate fluoride exposure is especially important for those experiencing disproportionately high prevalence of dental caries, such as rural Latino farmworkers and their children. Water is an important source of fluoride. This qualitative study examined water consumption beliefs and practices among Latino parents of young children in a rural community. Methods: Focus groups and open-ended in-depth interviews explored parents' beliefs about tap water, beverage preferences, and knowledge of fluoride. A questionnaire documented socio-demographic characteristics and water consumption practices. Qualitative analysis revealed how water-related beliefs, social and cultural context, and local environment shaped participants' water consumption. Results: The vast majority of participants (n = 46) avoided drinking unfiltered tap water based on perceptions that it had poor taste, smell, and color, bolstered by a historically justified and collectively transmitted belief that the public water supply is unsafe. Water quality reports are not accessible to many community residents, all of whom use commercially bottled or filtered water for domestic consumption. Most participants had little knowledge of fluoride beyond a general sense it was beneficial. While most participants expressed willingness to drink fluoridated water, many emphatically stated that they would do so only if it tasted, looked, and smelled better and was demonstrated to be safe. Conclusions: Perceptions about water quality and safety have important implications for adequate fluoride exposure. For vulnerable populations, technical reports of water safety have not only to be believed and trusted but matched or superseded by experience before meaningful change will occur in people's water consumption habits.

The diverse physical and chemical aspects of graphene nanosheets such as particle size surface area and edge chemistry were combined to fabricate a new supercapacitor electrode architecture consisting of a highly aligned network of large-sized nanosheets as a series of current collectors within a multilayer configuration of bulk electrode. Capillary driven self-assembly of monolayers of graphene nanosheets was employed to create a flexible, multilayer, free-standing film of highly hydrophobic nanosheets over large macroscopic areas. This nanoarchitecture exhibits a high-frequency capacitative response and a nearly rectangular cyclic voltammogram at 1000 mV/s scanning rate and possesses a rapid current response, small equivalent series resistance (ESR), and fast ionic diffusion for high-power electrical double-layer capacitor (EDLC) application.

Bioreactors containing sessile bacteria (biofilms) grown on hollow fiber membranes have been used for treatment of many wastestreams. Real time operational control of bioreactor performance requires detailed knowledge of the relationship between bulk liquid water quality and physiological transport at the biofilm-liquid interface. Although large data sets exist describing membrane-aerated bioreactor effluent quality, very little real time data is available characterizing boundary layer transport under physiological conditions. A noninvasive, microsensor technique was used to quantify real time ( approximately 1.5 s) changes in oxygen and proton flux for mature Nitrosomonas europaea and Pseudomonas aeruginosa biofilms in membrane-aerated bioreactors following exposure to environmental toxins. Stress response was characterized during exposure to toxins with known mode of action (chlorocarbonyl cyanide phenyl-hydrazone and potassium cyanide), and four environmental toxins (rotenone, 2,4-dinitrophenol, cadmium chloride, and pentachlorophenol). Exposure to sublethal concentrations of all environmental toxins caused significant increases in O(2) and/or H(+) flux (depending on the mode of action). These real time microscale signatures (i.e., fingerprints) of O(2) and H(+) flux can be coupled with bulk liquid analysis to improve our understanding of physiology in counter-diffusion biofilms found within membrane aerated bioreactors; leading to enhanced monitoring/modeling strategies for bioreactor control.

This study describes the application of a noninvasive direct microscopic observation method for characterizing fouling of a forward osmosis (FO) membrane. The effect of the draw solution concentration, membrane orientation, and feed spacer on FO fouling was systematically investigated in a cross-flow setup using latex particles as model foulant in the feedwater. Higher draw solution (DS) concentrations (and thus increased flux levels) resulted in dramatic increase in the surface coverage by latex particles, suggesting that the critical flux concept might be applicable even for the osmotically driven FO process. Under identical draw solution concentrations, the active-layer-facing-the-feed-solution orientation (AL-FS) experienced significantly less fouling compared to the alternative orientation. This may be explained by the lower water flux in AL-FS, which is consistent with the critical flux concept. The use of a feed spacer not only dramatically enhanced the initial flux of the FO membrane, but also significantly improved the flux stability during FO fouling. Despite such beneficial effects of using the feed spacer, a significant amount of particle accumulation was found near the spacer filament, suggesting further opportunities for improved spacer design. To the best of the authors' knowledge, this is the first direct microscopic observation study on FO fouling.

A flood irrigation system was constructed to remove nutrient-based water pollutants through the various natural treatment mechanisms of plants and microorganisms. Species of plants were allowed to proliferate naturally within the system. The succession of flora was then utilized as an index to evaluate the water purification efficiency of the flood irrigation system. The natural growth of plants during the test period indicated what part of the irrigation system would recover most efficiently from nutrient-based contamination. From the first stage of observation (50 days) to the second stage (50 days), the average processing efficiencies of Nitrate Nitrogen (NO3(-)-N) and Ortho-phosphate (PO4(3-)) were improved 1.7% and 70.3%, respectively. After the 60th day, the Compositae family flourished in the system. At the same time, removal rate of Nitrate Nitrogen was increased dramatically which may be related to prevalence of the Compositae family. Trends indicate that the Ortho-phosphate concentration of the irrigated water was low, and Brachiaria mutica of Poaceae were dominant which may have lead to the phenomenon of phosphorus released in the flood irrigation system.

The amount and distribution of six pharmaceutical compounds belonging to distinct therapeutic classes were investigated along the navigation channel of the Douro River estuary. Distinct spatial and temporal trends were considered and a total of 87 water samples were pre-concentrated by solid-phase extraction (SPE) and analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS) with an ion trap (IT) analyzer and electrospray ionization (ESI). The maximum concentrations found were 178ng/L for carbamazepine, 3.65ng/L for diazepam, 70.3ng/L for fenofibric acid, 3.18ng/L for propranolol, 15.7ng/L for trimethoprim and 53.3ng/L for sulfamethoxazole. Carbamazepine was the most ubiquitous compound with 100% positive detection frequency followed by propranolol (38%), trimethoprim (34%) and sulfamethoxazole (33%). The pharmaceutical compounds were quantified at higher levels in the lower stretch of the estuary, especially near the wastewater treatment plant (WWTP). The data proves that pollution of the Douro River estuary by pharmaceuticals is consistent and is occurring in a fairly constant manner in time, covering a wide area and displaying hot-spots. Individually, the concentration levels are not likely to cause acute effects, based on reference experimental data. However, the fact that complex mixtures exist gives cause for concern as regards potentially relevant toxicological risks. The study points out the need for continuous monitoring of contamination levels not only in the Douro River estuary but also in other major estuaries. Finally, the scenario supports the need for experimental studies on toxicological impacts on aquatic organisms at environmentally relevant concentrations.

A novel bioreactor system, consisting of two biologically active carbon (BAC) reactors in series, was developed for the simultaneous removal of nitrate and arsenic from a synthetic groundwater supplemented with acetic acid. A mixed biofilm microbial community that developed on the BAC was capable of utilizing dissolved oxygen, nitrate, arsenate, and sulfate as the electron acceptors. Nitrate was removed from a concentration of approximately 50 mg/L in the influent to below the detection limit of 0.2 mg/L. Biologically generated sulfides resulted in the precipitation of the iron sulfides mackinawite and greigite, which concomitantly removed arsenic from an influent concentration of approximately 200 mg/L to below 20 mg/L through arsenic sulfide precipitation and surface precipitation on iron sulfides. This study showed for the first time that arsenic and nitrate can be simultaneously removed from drinking water sources utilizing a bioreactor system.

Disinfection byproducts (DBPs) in municipal supply water are a concern because of their possible risks to human health. Risk assessment studies often use DBP data in water distribution systems (WDS). However, DBPs in tap water may be different because of stagnation of the water in plumbing pipes (PP) and heating in hot water tanks (HWT). This study investigated occurrences and developed predictive models for DBPs in the PP and the HWT of six houses from three municipal water systems in Quebec (Canada) in a year-round study. Trihalomethanes (THMs) in PP and HWT were observed to be 1.4-1.8 and 1.9-2.7 times the THMs in the WDS, respectively. Haloacetic acid (HAAs) in PP and HWT were observed to be variable (PP/WDS = 0.23-2.24; HWT/WDS = 0.53-2.61). Using DBPs occurrence data from these systems, three types of linear models (main factors; main factors, interactions and higher orders; logarithmic) and two types of nonlinear models (three parameters Logistic and four parameters Weibull) were investigated to predict DBPs in the PP and HWT. Significant factors affecting DBPs formation in the PP and HWT were identified through numerical and graphical techniques. The R(2) values of the models varied between 0.77 and 0.96, indicating excellent predictive ability for THMs and HAAs in the PP and the HWT. The models were found to be statistically significant. The models were validated using additional data. These models can be used to predict DBPs increase from WDS (water entry point of house) to the PP and HWT, and could thereby help gain a better understanding of human exposure to DBPs and their associated risks.

Urban sources of water pollution have often been cited as the primary cause of poor water quality in receiving water bodies (RWB), and recently many studies have been conducted to investigate both continuous sources, such as wastewater-treatment plant (WWTP) effluents, and intermittent sources, such as combined sewer overflows (CSOs). An urban drainage system must be considered jointly, i.e., by means of an integrated approach. However, although the benefits of an integrated approach have been widely demonstrated, several aspects have prevented its wide application, such as the scarcity of field data for not only the input and output variables but also parameters that govern intermediate stages of the system, which are useful for robust calibration. These factors, along with the high complexity level of the currently adopted approaches, introduce uncertainties in the modelling process that are not always identifiable. In this study, the identifiability analysis was applied to a complex integrated catchment: the Nocella basin (Italy). This system is characterised by two main urban areas served by two WWTPs and has a small river as the RWB. The system was simulated by employing an integrated model developed in previous studies. The main goal of the study was to assess the right number of parameters that can be estimated on the basis of data-source availability. A preliminary sensitivity analysis was undertaken to reduce the model parameters to the most sensitive ones. Subsequently, the identifiability analysis was carried out by progressively considering new data sources and assessing the added value provided by each of them. In the process, several identifiability methods were compared and some new techniques were proposed for reducing subjectivity of the analysis. The study showed the potential of the identifiability analysis for selecting the most relevant parameters in the model, thus allowing for model simplification, and in assessing the impact of data sources for model reliability, thus guiding the analyst in the design of future monitoring campaigns. Further, the analysis showed some critical points in integrated urban drainage modelling, such as the interaction between water quality processes on the catchment and in the sewer, that can prevent the identifiability of some of the related parameters.

Quantitative risk analysis (QRA) is a systematic approach for evaluating likelihood, consequences, and risk of adverse events. QRA based on event (ETA) and fault tree analyses (FTA) employs two basic assumptions. The first assumption is related to likelihood values of input events, and the second assumption is regarding interdependence among the events (for ETA) or basic events (for FTA). Traditionally, FTA and ETA both use crisp probabilities; however, to deal with uncertainties, the probability distributions of input event likelihoods are assumed. These probability distributions are often hard to come by and even if available, they are subject to incompleteness (partial ignorance) and imprecision. Furthermore, both FTA and ETA assume that events (or basic events) are independent. In practice, these two assumptions are often unrealistic. This article focuses on handling uncertainty in a QRA framework of a process system. Fuzzy set theory and evidence theory are used to describe the uncertainties in the input event likelihoods. A method based on a dependency coefficient is used to express interdependencies of events (or basic events) in ETA and FTA. To demonstrate the approach, two case studies are discussed.

We investigated the effect of antibody solution conditions (ionic strength, pH, IgG concentration, buffer composition, and aggregate level (dimer content)) on filter performance for a virus removal filtration process using the Planova 20N, a virus removal filter. Ionic strength and pH affected the filter flux. A consistent high flux was maintained at an ionic strength greater than 10 mM and at pH 4-8 under a typical buffer composition (sodium chloride, citrate, acetate, and phosphate). Optimum IgG concentration was 10-20 mg/mL allowing for high throughput (kg/m(2) of IgG). Dimer content negligibly affected the flux level. Under high throughput conditions, virus spiking did not affect flux whereas a parvovirus logarithmic reduction value greater than 5 was maintained. From the results of zeta potential analyses for IgG and the membrane, we considered that electrostatic interactions between antibodies and the membrane affect filter performance (flux level and throughput). These results indicate that the Planova 20N filter is applicable for a wide range of solution conditions typically used in antibody processing.(c) 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010.

The aim of this study was to examine the performance of intermittently loaded, 150 mm-diameter stratified filter columns of 2 depths (0.65 and 0.375 m) comprising different media - sand, crushed glass and soil - in polishing the effluent from a laboratory horizontal flow biofilm reactor (HFBR) treating synthetic domestic-strength wastewater. The HFBR has been successfully used to remove organic carbon and ammonium-nitrogen (NH(4)-N) from domestic wastewater. In this treatment method, wastewater is allowed to flow over and back along a stack of polyvinyl chloride (PVC) sheets. Biofilms on the sheets reduce organic carbon, suspended matter, and nutrients in the wastewater, but to achieve the quality of a septic tank system, additional treatment is required. In all filters, at a hydraulic loading rate of 100 L m(-2) d(-1), 40-65% of chemical oxygen demand (COD) and practically 100% of total suspended solids (TSS) were removed, nitrification was complete, and bacterial numbers were reduced by over 80%, with best removals achieved in the soil filters (93%). Soil polishing filters with the depth of 0.65 m performed best in terms of organic carbon, total nitrogen (Tot-N) and bacterial removal. Data from this preliminary study are useful in the design of treatment systems to polish secondary wastewaters with similar water quality characteristics.

We investigated in solid medium, in water microcosm co-cultures and by light and transmission electron microscopy the influence of Legionella pneumophila Lp-1, Pseudomonas aeruginosa ATCC 27853, Burkholderia cepacia ATCC 25416 and Pseudomonas fluorescens SSD35 on the growth and survival of Acanthamoeba polyphaga. The infection with L. pneumophila was microscopically characterized by the presence of few bacteria inside protozoa at 4th h, and by the beginning of disruptive effects in late phase of trial. In water microcosm studies, performed at different temperature, the more significant interactions were observed at 30 degrees C. In these conditions, L. pneumophila caused a marked reduction in trophozoite and cyst counts from the 4th day until the end of incubation (11 days). B. cepacia showed, by microscopic observation, few and generally single rods within protozoan phagosomes and caused a light reduction of trophozoite viability and cyst formation in co-cultures. A more invasive type of endocytosis, characterized by an early invasion with the presence of a high bacteria number inside amoebae, was observed for Pseudomonas strains. P. fluorescens produced a violent lysis of the host, whereas P. aeruginosa did not cause lysis or suffering. These results underline that water bacteria other than legionella are capable of intracellular survival in Acanthamoeba, influencing the protozoa viable cycle.

A new and simple strategy for the dispersion of single-wall carbon nanotubes in aqueous media is presented which does not rely on hydrophobic interactions between the polypeptidic dispersing agent and the nanotubes, and allows the surface charge of the resulting conjugate materials to be controlled.

We design a novel nano-gap electrode to measure the current of DNA molecule, by which the current-voltage characteristics of individual native DNA, Ag-DNA and Ni-DNA molecules are obtained, respectively. The results show that the voltage gap of Ag- and Ni-DNA is higher than that of native DNA, and the conductance is lower than native DNA in neutral environment. The structure transition from B- to Z-DNA is observed in the presence of high concentrations of nickel ions and Ag-DNA appears chaos state by STM image and U-V spectra characterization. But in alkaline environment, the conductance of Ni-DNA rises and the voltage gap decreases with the increasing of nickel ion concentration denotes that the conductive ability of Ni-DNA is higher than that of native DNA.

Water shortages and water pollution are a global problem. Increases in population can have further acute effects on water cycles and on the availability of water resources. Thus, wastewater management plays an important role in mitigating negative impacts on natural ecosystems and human environments and is an important area of research. In this study, we modelled catchment-scale hydrology, including water balances, rainfall, contamination, and urban wastewater treatment. The entire water resource system of a basin, including a forest catchment and an urban city area, was evaluated synthetically from a spatial distribution perspective with respect to water quantity and quality; the Life Cycle Assessment (LCA) technique was applied to optimize wastewater treatment management with the aim of improving water quality and reducing CO(2) emissions. A numerical model was developed to predict the water cycle and contamination in the catchment and city; the effect of a wastewater treatment system on the urban region was evaluated; pollution loads were evaluated quantitatively; and the effects of excluding rainwater from the treatment system during flooding and of urban rainwater control on water quality were examined. Analysis indicated that controlling the amount of rainwater inflow to a wastewater treatment plant (WWTP) in an urban area with a combined sewer system has a large impact on reducing CO(2) emissions because of the load reduction on the urban sewage system.

The present paper shows the results obtained through an experimental activity carried out on a pilot-scale plant using an innovative technology which couples the granular aerobic sludge with the sequencing batch process. Treatment efficiency and operation costs were evaluated in order to assess feasibility of this new technology for the upgrading of the existing continuous flow activated sludge treatment plant located in Casal Monastero, a decentralized area of the City of Rome. During start-up (about 3 months), the granular aerobic sludge was developed by controlling the dissolved oxygen concentration, the value of pH and the up-flow velocity. Besides, the influent organic loading was progressively increased starting from 0.1 kg/m(3) d up to 0.9 kg/m(3) d. In order to improve nitrogen removal, an anoxic phase was temporary added to the operative cycle. Complete development of the granular sludge determined an appreciable improvement of the denitrification process which allowed to eliminate the anoxic phase. At regime conditions, the plant was operated with 3 daily cycles, each one of 8 h. The new system showed a reduced sludge production (of about 20-35%) as compared to the existing plant, along with high removal efficiency of both Chemical Oxygen Demand (COD) and nitrogen. However, the operation was discontinuous and strictly related to the strength of the granular sludge. Therefore, a careful monitoring is recommended in order to control operation and performance of this new system.