bluuebunny/crossref_metadata_2025 huggingface dataset:
On-line determination of sludge settling velocity for flux-based real-time control of secondary clarifiers
Authors: Lynggaard-Jensen A. , Lading L.
Published: September 2006

The state diagram for operation of secondary clarifiers is used to design a control algorithm for the return sludge pumping and determination of the actual hydraulic capacity of the biological step of a wastewater treatment plant. On-line input for the control algorithm is derived from a sludge volume sensor and a suspended solids sensor in the form of software sensors giving values for the sludge settling characteristics – settling velocity, sludge volume index, initial settling velocity and the exponent in the Vesilind equation – allowing the control to accommodate the ever changing settling characteristics and thereby keep the suspended solids flux in the clarifiers in balance for both dry weather flows and during rain events. The control algorithm has been implemented, tested and set into normal operation on a full scale wastewater treatment plant.
Rain events and their effect on effluent quality studied at a full scale activated sludge treatment plant
Authors: Wilén B.-M. , Lumley D. , Mattsson A. , Mino T.
Published: September 2006

The effect of rain events on effluent quality dynamics was studied at a full scale activated sludge wastewater treatment plant which has a process solution incorporating pre-denitrification in activated sludge with post-nitrification in trickling filters. The incoming wastewater flow varies significantly due to a combined sewer system. Changed flow conditions have an impact on the whole treatment process since the recirculation to the trickling filters is set by the hydraulic limitations of the secondary settlers. Apart from causing different hydraulic conditions in the plant, increased flow due to rain or snow-melting, changes the properties of the incoming wastewater which affects process performance and effluent quality, especially the particle removal efficiency. A comprehensive set of on-line and laboratory data were collected and analysed to assess the impact of rain events on the plant performance.
Novel TiO2 nanocatalysts for wastewater purification: tapping energy from the sun
Authors: Liu Y. , Li J. , Qiu X. , Burda C.
Published: September 2006

Water treatment using TiO2 semiconductor as a durable heterogeneous photocatalyst has been the focus of environmentalists in recent years. Currently, we developed an inexpensive and highly efficient approach for synthesizing nitrogen-doped TiO2 with lower band-gap energy that can respond to visible light. Doping on the molecular scale led to an enhanced nitrogen concentration of up to 21.8%. Reflectance measurements showed the synthesized N-doped TiO2 nanoparticles are catalytically active with the absorbance that extends into the visible region up to 600 nm. The water purification potential of this new class of compound was evaluated by studying the photodegradation of Acid Orange 7 (AO7) and E. coli. Experiments were conducted to compare the photocatalytic activities of N-doped TiO2 nanocatalysts and commercially available Degussa P25 power under identical solar light exposure. N-doped TiO2 demonstrated superior photocatalytic activities in both chemical compound degradation and bactericidal reactions. The result of this study shows the potential of applying new generations of catalyst for wastewater purification and disinfection.
Effects of exposure times on the toxic response of ammonia oxidizing mixed culture (AOMC) to phenol and chlorinated phenols
Authors: Tantasut J. , Satoh H. , Parkpian P. , Mongkolsuk S.
Published: September 2006

This study investigated the effect of exposure times on the response of ammonia oxidizing mixed culture (AOMC) to phenolic compounds while having the future goal to develop a biosensor using AOMC for toxicity monitoring. AOMC was used instead of purified nitrifying culture because of the ease of culture development. The oxygen utilization rate (OUR) was measured during three exposure periods; 0–15, 25–40 and 50–65 min. It was found that phenolic compounds have a strong inhibitory effect on AOMC. The percentage of OUR reduction increased with higher concentrations and the extended exposure times improved the toxic response of AOMC, especially to the lower concentrations (0.25, 0.50, 1.0 mg/L). Further, AOMC detoxifying mechanisms might result in the reduction of toxic response when the longest exposure time was applied. However, at the higher concentrations (2.5 and 5.0 mg/L), the extended exposure times did not have a critical effect on the response pattern of AOMC, especially for phenol and mono-chlorinated phenols. It was illustrated that AOMC is very sensitive to phenolic compounds and its sensitivity is high enough for the detection of phenolic compounds at the level of effluent standard in Thailand and Japan with a rapid response time of 15 min. To improve the sensitivity of AOMC to low phenolic compound concentrations, an extended exposure time of 25–40 min would be recommended.
Evaluation of the ReVAQ project to achieve safe use of wastewater sludge in agriculture
Authors: Malmqvist P.-A. , Kärrman E. , Rydhagen B.
Published: September 2006

The use of wastewater sludge on arable land in Sweden has been limited for some years due to the low quality, in some respects, of the sludge and to the reluctance of farmers and the food industry to use it. To improve the quality of the sludge, the ReVAQ project has been started, and it now involves seven municipal wastewater organisations. The goal of the project is to introduce a process in which the quality is successively improved by a series of actions taken by society. These actions include tracking and eliminating sources of heavy metals and other substances. As there are numerous sources of some of the substances, the work concentrates on the major sources. Another important activity is to provide information to the users of the wastewater system. The project is being evaluated by Urban Water AB. The results from the first two years indicate that it may be possible to reach the primary technical goal: to obtain a sludge quality that corresponds to that of household wastewater. The more ambitious goal of reaching a quality corresponding to that of WC water (the sum of urine and faeces) does not seem realistic without far-reaching changes in society. The organisations involved, which take the work seriously and are goal-oriented, have achieved measurable results in a short time. The work is also accepted and supported by the board members. More effort is needed, however, to inform the users about the system, and to [motivate them to] change their behaviour regarding matters such as the purchase of everyday products and the use of the toilet facilities.
Use of citric acid for heavy metals extraction from contaminated sewage sludge for land application
Authors: del Mundo Dacera D. , Babel S.
Published: September 2006

Recent studies revealed that organic acids such as citric and oxalic acids seemed to be more promising as chemical extracting agents for removal of heavy metals from contaminated sludge, since they are biodegradable and can attain a higher metal extraction efficiency at mildly acidic pH compared to other extracting agents. Results of a lab-scale study on the efficiency of citric acid in the extraction of chromium (Cr), copper (Cu), lead (Pb), nickel (Ni) and zinc (Zn) from anaerobically digested sludge, revealed that citric acid seemed to be highly effective in extracting Cr (at 100%), Cu (at 88%), Ni (at 98%) and Zn (at 100%) at pH 2.33, mostly at 5 days leaching time except for Cu and Zn, which are at 1 day and 2 h contact times respectively. Lead removal at the same pH was also high at 95% but at a longer leaching time of 11 days. At pH 3, citric acid seemed to be highly effective in extracting Pb (at 100%) at 1 day leaching time, although higher removals were also attained for Ni (70%) and Zn (80%) at only 2 h leaching time. Chemical speciation studies showed that Cr, Cu and Ni in the sludge sample seem to predominate in residual fractions, while Pb and Zn were found mostly bound to organic and inorganic matter forms, hence the potential of the sludge for land application.
Removal of nitrogen, phosphorus and other priority (hazardous) substances from WWTP effluent
Authors: Miska V. , Menkveld H.W.H. , Kuijer L. , Boersen M. , van der Graaf J.H.J.M.
Published: September 2006

More stringent effluent criteria will be required in the near future for the so-called priority substances listed in the Annex of the European Water Framework Directive (WFD) 2000/60/EC. This includes heavy metals, volatile and semi-volatile organic substances, pesticides and polychlorinated biphenyls. The Fraunhofer Institute suggested FHI values for these substances in water. National Dutch legislation, the Vierde Nota WaterHuishouding (NWH) introduced in 1998 ‘maximum tolerable risk concentrations’ (MTR). These include requirements for nutrients: Ptot<0.15 mg/l and Ntot<2.2 mg/l. The MTR values are being used until the FHI values become effective. Investigation into possible effluent polishing techniques is required in order to reach these objectives. During pilot research with tertiary denitrifying multi-media and biological activated carbon filtration at the WWTP Utrecht in the Netherlands, simultaneous nutrient removal to MTR quality was observed. Furthermore, simultaneous removal of heavy metals, 17β-estradiol, bisphenol A and nonylphenols to extreme low concentrations by denitrifying activated carbon filtrated is achieved.
Performance of high-rate sludge digesters fed with sonicated sludge
Authors: Mao T. , Show K.-Y.
Published: September 2006

A major limitation of anaerobic sludge digestion is the long hydraulic retention time (HRT) required for satisfactory stabilization which results in large digester size. This study explored a possibility of operating digesters at shortened HRTs by sonication pretreatment of secondary sludges. Four identical digesters designated D1, D2, D3 and D4 were fed with untreated and sludge sonicated at densities of 0.18 W/ml, 0.33 W/ml and 0.52 W/ml, respectively. All digesters were operated at three HRTs of 8-day, 4-day and 2-day. Comparing with the control digester (D1), total solids removal efficiencies improved by 12–19%, 17–36% and 20–39% in digesters D2, D3 and D4, respectively. The volatile solids removal was also increased by 11–21%, 17–33% and 19–36% in the respective digesters. The improved solids degradation corresponded with increase in biogas production by 1.4–2.5, 1.9–3.0 and 1.6–3.1 times, respectively. Increase in methane composition by 2–17% was also noted in all digesters fed with sonicated sludge. An analysis indicated that sonication pretreatment could enhance degradation of carbon, nitrogen and sulfur substances in the digestion. The study suggested that sonication of sludge is a possible pretreatment to shorten the digester operating HRT with improvement in solids degradation, biogas production and methane content. It can be deduced that to maintain a consistent solids loading at a desire performance, sludge digester with smaller size can be designed.
Comparison of two types of inocula during acclimation and stable operation for nitrophenol biodegradation in an anaerobic-aerobic SBR
Authors: Vargas A. , González D. , Estival A. , Buitrón G.
Published: September 2006

This work presents a comparison of two inocula used for the acclimation of two anaerobic-aerobic sequencing batch bioreactors used for toxic wastewater treatment. The bioreactors were acclimated with different types of sludge: one coming from an anaerobic wastewater treatment plant and the other one from a conventional aerobic activated sludge plant. The model toxic compound was p-nitrophenol, which is reduced to p-aminophenol during the initial anaerobic phase of the reaction, and later mineralized during a posterior aerated reaction phase. Biodegradation of the compounds was monitored using UV/Vis spectrophotometry. After acclimation stabilization of the sludge and of the process was also monitored. Results show that there is no significant difference in acclimation times and stability of the process between the two employed inocula, and thus an originally anaerobic inoculum presents no apparent advantage over a more easily accessible aerobic one.
Study on performance of granular ANAMMOX process and characterization of the microbial community in sludge
Authors: Yang Y. , Zuo J. , Quan Z. , Lee S. , Shen P. , Gu X.
Published: September 2006

Anaerobic Ammonium Oxidation (ANAMMOX) is a novel biological nitrogen removal process, which is regarded as the most economical process at present. In this paper, two lab-scale UASB reactors, one of which was inoculated with the mixture of anaerobic sludge and aerobic sludge, the other with river sediments, were started up, using the inorganic synthetic water containing ammonium and nitrite as influent. After 421 days' and 356 days operation respectively, the ammonium removal efficiencies in two reactors reached 94% and 86% respectively, the total nitrogen volumetric loading rates were 2.5 and 1.6 kgN/m3.d. ANAMMOX granules were obtained in both reactors; the color of most granules was brown, but some of them were red. Based on the observation and studies on the microstructure of the granules, three kinds of ANAMMOX granular sludge formation mechanisms were proposed: adhering biofilm and disintegrated granular core mechanism, adhering biofilm and inorganic core mechanism and the self-coherence mechanism. For phylogenetic characterization of anaerobic ammonium oxidizers,16S rDNA approach was performed using Planctomycetales-specific PCR amplification. The dominant anammox bacteria occupied more than 90% of Planctomycetales-specific bacteria, and 27% of all bacteria in reactors. The dominant anammox bacteria distantly related to all currently reported candidate anammox genera. Functional gene of amoA was analyzed to investigate the ‘aerobic’ ammonium-oxidizing bacteria in β-Proteobacteria. The ‘aerobic’ ammonium-oxidizing bacteria were more diverse than anammox bacteria, but most of them clustered in anoxic ammonium-oxidizing Nitrosomonas eutropha/europaea groups. The composition of ‘aerobic’ ammonium-oxidizing bacteria is only 2% of all of bacteria in reactors.
Effect of bubble flow velocity on drag-force and shear stress working on submerged hollow fibre membrane
Authors: Nagaoka H. , Kurosaka M. , Shibata N. , Kobayashi M.
Published: September 2006

This study is aimed at elucidating the mechanism by which rising air bubbles induce shear stress on hollow fibre membrane surfaces. Shear stress on hollow fibre membrane surfaces (laterally-set and vertically-set) caused by aeration was measured directly using a two-direction load sensor. In the laterally-set hollow fibre module, time-averaged upward-direction shear stress on the membrane surface was compared to theoretical shear stress values considering the effect of water flow on membrane surface. Measured time-average shear stress values were almost 200 times larger than theoretical values implying strong interactions between bubbles and solid surface. In the vertically-set membrane module, velocity measurement of bubble flow using laser Doppler velocimeter revealed that drag force working on membrane surface was closely related to upward-direction water velocity. Also fluctuation of drag force and shear force on membrane surface was found to be related to velocity fluctuation (turbulence).
Plant-wide (BSM2) evaluation of reject water treatment with a SHARON-Anammox process
Authors: Volcke E.I.P. , Gernaey K.V. , Vrecko D. , Jeppsson U. , van Loosdrecht M.C.M. , Vanrolleghem P.A.
Published: September 2006

In wastewater treatment plants (WWTPs) equipped with sludge digestion and dewatering systems, the reject water originating from these facilities contributes significantly to the nitrogen load of the activated sludge tanks, to which it is typically recycled. In this paper, the impact of reject water streams on the performance of a WWTP is assessed in a simulation study, using the Benchmark Simulation Model no. 2 (BSM2), that includes the processes describing sludge treatment and in this way allows for plant-wide evaluation. Comparison of performance of a WWTP without reject water with a WWTP where reject water is recycled to the primary clarifier, i.e. the BSM2 plant, shows that the ammonium load of the influent to the primary clarifier is 28% higher in the case of reject water recycling. This results in violation of the effluent total nitrogen limit. In order to relieve the main wastewater treatment plant, reject water treatment with a combined SHARON-Anammox process seems a promising option. The simulation results indicate that significant improvements of the effluent quality of the main wastewater treatment plant can be realized. An economic evaluation of the different scenarios is performed using an Operating Cost Index (OCI).
Linking watershed and eutrophication modelling for the Shihmen Reservoir, Taiwan
Authors: Liu W.C. , Chen H.H. , Hsieh W.H. , Chang C.H.
Published: September 2006

The Shihmen Reservoir, located in northern Taiwan, features the second storage volume of impoundments on the island. The watershed of the Shihmen Reservoir has been subjected to serious pollutants due to anthropogenic interference. This study applies a watershed model, BASINS, to simulate the flow and nutrients loads from the watershed. BASINS then drives the CE-QUAL-W2 model for water quality predictions in the reservoir. The watershed modelling results are compared with field data. They reveal that significant nutrient loads were generated from the watershed during storms. The model calibration and verification were achieved with water surface elevation, temperature, and water quality constituents including nutrients, dissolved oxygen, and chlorophyll a in the reservoir using the eutrophication model.
Water quality assessment and apportionment source of pollution from neighbouring rivers in the Tapeng Lagoon (Taiwan) using multivariate analysis: a case study
Authors: Liao S.-W. , Sheu J.-Y. , Chen J.-J. , Lee C.-G.
Published: September 2006

Factor analysis was conducted to explain the characteristics and variation in the quality of water during the disassembly of oyster frames and fishery boxes. The result shows that the most important latent factors in the Tapeng Lagoon are the ocean factor, the primary productivity factor, and the fishery pollution factor. Canonical discriminant analysis is applied to identify the source of pollution in neighbouring rivers outside the Tapeng Lagoon. The two constructed discriminant functions (CDFs) showed a marked contribution to all the discriminant variables, and that total nitrogen, algae, dissolved oxygen, and total phosphate combined in the nutrient effect factor. The recognition capacities in these two CDFs were 95.6% and 4.4%, respectively. The water quality in the Kaoping river most strongly affected the water quality in the Tapeng Lagoon. Disassembling the oyster frames and fishery boxes improved the water quality markedly. However, environmental topographic conditions indicate that strengthening stream pollution prevention and constructing another entrance to the ocean are the best approaches for improving the quality of water in the Tapeng Lagoon by reducing eutrophication. These approaches and results yield useful information concerning habitat recovery and water resource management.
An integrated system for nonpoint source pollution modelling and management
Authors: Zhang D. , Chen J. , Du P. , He W.
Published: September 2006

Modelling the impact of nonpoint source pollution (NSP) is a complex problem that has troubled water resource managers for many years when trying to set up proper management practices in catchment areas. In this paper, an integrated decision support system, NPSDSS (nonpoint source decision support system), was introduced to resolve this problem in a relatively easy way. The system was developed in a unique platform and integrated with the IMPULSE (integrated model of nonpoint source pollution processes) model, a stand alone geographic information system (GIS) toolbox, a well-structured database, a measure screening model, and an expert system, as well. The system has been applied in the Dianchi Lake catchment area and shown to give a good perspective on providing useful recommendations for appropriate NSP management.
Calibration of CE-QUAL-W2 for a monomictic reservoir in a monsoon climate area
Authors: Chung S.W. , Oh J.K.
Published: September 2006

The impact of inflow mixing on reservoir stratification is significant for reservoirs situated in a monsoon climate area. It cause difficulty in the calibration of a two-dimensional hydrodynamic and water quality model, CE-QUAL-W2 that was recently adopted for a real-time turbidity monitoring and modelling system (RTMMS) for a reservoir in Korea. This paper presents a systematic calibration and verification processe of the model for the reservoir. A sensitivity analysis showed that wind sheltering, Chezy, and sediment heat exchange coefficients are most sensitive to stratification structure. Inflow temperature was very sensitive during a year of normal precipitation, but it is not significant during a year of drought. Residual analysis revealed that the model has shortcomings in the simulation of water temperature near the metalimnetic zone without calibration. After calibration, however, the absolute mean errors between observed and simulated values were placed within 0.116–1.190 °C. Its performance was maintained under heavy flood events during the verification stage, which implies that the model is ready to use for the simulation of turbidity plume in the RTMMS under various hydrologic conditions. The suggested model calibration strategy and relevant results may be adopted for other reservoirs located in a monsoon climate area.
Sustainable and integrated water resources management for the coastal areas of Shandong Province, China
Authors: Kutzner R. , Zhang B. , Kaden S. , Geiger W. F.
Published: September 2006

Water scarcity and water pollution are severe problems in the Northern part of China, strongly affecting socio-economic development and standards of living and environment. The Shandong province is specifically plagued by water scarcity. In the coastal catchments of the Shandong province the water scarcity is even increased due to saltwater intrusion, reducing the usability of water resources available. The pressing water problems in the costal catchments in the Shandong province and resulting socio-economic troubles forced the Chinese authorities to implement a variety of measures to relieve water scarcity and abate saltwater intrusion. But not much has been achieved so far as the measures are not coordinated in their effects and cost-benefit relations have not been considered sufficiently. Such a situation calls for good, which means integrated, sustainable water management. The assessment of this situation in the project “Flood Control and Groundwater Recharge in Coastal Catchments” financed by the German Ministry of Research and Education is presented. Further objectives and first ideas for an IWRM-concept are explained. These ideas are based on concepts developed in Germany in the context of the fulfilment of the European Water Framework Directive.
Integrated faecal sludge treatment and recycling through constructed wetlands and sunflower plant irrigation
Authors: Koottatep T. , Polprasert C. , Hadsoi S.
Published: September 2006

Faecal sludge (FS) from the on-site sanitation systems is a nutrient-rich source but can contain high concentrations of toxic metals and chemicals and infectious micro-organisms. The study employed 3 vertical-flow CW units, each with a dimension of 5×5×0.65 m (width×length×media depth) and planted with cattails (Typha augustifolia). At the solid loading rate of 250 kg total solids (TS)/m2.yr and a 6-day percolate impoundment, the CW system could achieve chemical oxygen demand (COD), TS and total Kjeldahl nitrogen (TKN) removal efficiencies in the range of 80–96%. A solid layer of about 80 cm was found accumulated on the CW bed surface after operating the CW units for 7 years, but no clogging problem has been observed. The CW percolate was applied to 16 irrigation sunflower plant (Helianthus annuus) plots, each with a dimension of 4.5×4.5 m (width×length). In the study, tap water was mixed with 20%, 80% and 100% of the CW percolate at the application rate of 7.5 mm/day. Based on a 1-year data in which 3 crops of plantation were experimented, the contents of Zn, Mn and Cu in soil of the experimental plots were found to increase with increase in CW percolate ratios. In a plot with 100% of CW percolate irrigation, the maximum Zn, Mn and Cu concentrations of 5.0, 12.3 and 2.5 mg/kg, respectively, were detected in the percolate-fed soil, whereas no accumulation of heavy metals in the plant tissues (i.e. leaves, stems and flowers) of the sunflower were detected. The highest plant biomass yield and oil content of 1000 kg/ha and 35%, respectively, were obtained from the plots fed with 20% or 50% of the CW percolate.
Evaluation of phytotoxic elements, trace elements and nutrients in a standardized crop plant, irrigated with raw wastewater treated by APT and ozone
Authors: Orta de Velásquez M.T. , Rojas-Valencia M.N. , Reales-Pineda A.C.
Published: September 2006

This project studied the benefits of applying Advanced Primary Treatment (APT) and ozone (O3) to raw wastewater destined for reuse in agriculture. The ozone was applied directly to raw wastewater, as well as to wastewater already treated with APT, and the results compared against a control sample of potable water. The experimental conditions that reported the best results was wastewater treated with O3 (at a dose of 4.8 mg/L, at pH 7, temperature 23°C, for 1 hr), given that it met standards in force in México with regard to micro-organism and heavy metal content. Under these conditions, after 15 min of ozonation, 100% destruction of the following bacteria was observed: V. cholerae, S. typhi as well as total and faecal coliforms. Destruction of helminth eggs and Giardia sp. took one hour. No phytotoxic elements or heavy metals were found. The balance of nutrients N:P:K (300:100:200 mg/kg) required for lettuce growth, was found in wastewater subjected to both treatment plans. However, ozone favoured the nitrification and assimilation of the nutrients, by contributing oxygen to the soil. Therefore, these conditions produced the greatest lettuce growth, the entire plant averaging 38 cm in length and 125 g. in weight. Moreover, a better appearance of the leaves was also noted.
Role of extracellular exopolymers in biological phosphorus removal
Authors: Liu Y. , Yu S. , Xue G. , Zhao F.
Published: September 2006

Three sequencing batch reactors (SBRs) supplied with different carbon sources were investigated. The system supplied with glucose gained the best enhanced biological phosphorus removal (EBPR), although all of them were seeded from the same sludge. With the measurement of poly-β-hydroxyalkanoate (PHA) concentration, phosphorus content in sludge and extracellular exopolymers (EPs) with scanning electron microscopy (SEM) combined with energy dispersive spectrometry (EDS), it was found that the biosorption effect of EPs played an important role in phosphorus removal and that the amount of PHA at the end of anaerobic phase was not the only key factor to determine the following phosphorus removal efficiency.
Boosting nitrification by membrane-attached biofilm
Authors: Wu C.Y. , Ushiwaka S. , Horii H. , Yamagiwa K.
Published: September 2006

Nitrification is a key step for reliable biological nitrogen removal. In order to enhance nitrification in the activated sludge (AS) process, membrane-attached biofilm (MAB) was incorporated in a conventional activated sludge tank. Simultaneous organic carbon removal and nitrification of the MAB incorporated activated sludge (AS+MAB) process was investigated with continuous wastewater treatment. The effluent TOC concentration of AS and the AS+MAB processes were about 6.3 mg/L and 7.9 mg/L, respectively. The TOC removal efficiency of both AS and AS+MAB were above 95% during the wastewater treatment, indicating excellent organic carbon removal performance in both processes. Little nitrification occurred in the AS process. On the contrary, successful nitrification was obtained with the AS+MAB process with nitrification efficiency of about 90%. The volumetric and surface nitrification rates were about 0.14 g/Ld and 6.5 g/m2d, respectively. The results clearly demonstrated that nitrification in the conventional AS process was boosted by MAB. Furthermore, the microfaunal population in the AS+MAB process was different from that in the AS process. The high concentration of rotifers in the AS+MAB process was expected to decrease the generation of excess sludge in the process.
Calcium effect on fermentative hydrogen production in an anaerobic up-flow sludge blanket system
Authors: Chang F.-Y. , Lin C.-Y.
Published: September 2006

The effects of calcium ions on a granular fermentative hydrogen production system were investigated in four lab-scale UASB reactors that fed on sucrose (20 g COD/L). The reactors were seeded with anaerobic sewage sludge microflora and operated at a temperature of 35±1°, pH of 6.7 with hydraulic retention times (HRTs) of 24–6 h. The experimental results indicated that calcium ion addition (75∼150 mg/L) could enhance the granulation and elevate hydrogen production efficiency. However, an overly-high calcium concentration (300 mg-Ca+2/L) deteriorated the hydrogen productivity. A calcium concentration of 150 mg-Ca+2/L resulted in a peak HP of 3.6 mol H2/mol-sucrose and HPR of 807 mmol-H2/L-d at HRTs of 8 and 6 h, respectively. The EPS concentration of biohydrogenic biomass was higher than that of the aerobic or methanogenic biomass. The protein/carbon-ratio ranged from 0.17 to 0.26%. The multinomial regression analysis shows that the 75∼150 mg-Ca+2/L calcium concentrations and HRT of 6 h were the optimal operating conditions to efficiently produce hydrogen.
Disruption of granules by hydrodynamic force in internal circulation anaerobic reactor
Authors: Wu J. , Lu Z.Y. , Hu J.C. , Feng L. , Huang J.D. , Gu X.S.
Published: September 2006

A process of granule disruption by hydrodynamic force is discussed in this paper. Shear force and attrition among granules originated from hydrodynamic force are the main causes of the disruption. Since it is positively correlated to the attrition force, the shear force is utilized to describe the effect of hydrodynamic force on granule disruption. In the experiment, when increase rate of average shear rate (IRγ) of the 1st stage is about 0.2 s−1·d−1, the granules are disrupted; while re-granulation could develop when IRγ is about 0.07 s−1·d−1; even when the shear rate is as high as about 30 s−1, the granulation rate keeps stably at a relatively high level, which shows that granules could bear the high hydrodynamic force only if it increases by low increase rate. The experimental results would be valuable for the operation and controlling of the upflow reactors.
Evaluation of a MF membrane system composed of pre coagulation-sedimentation and chlorination for water reuse
Authors: Lee S.H. , Lee B.C. , Moon S.Y. , Choi Y.S. , Jang N.Y. , Watanabe Y.
Published: September 2006

In this research, we investigated the variation of transmembrane pressure and permeate water quality in pre-coagulation and sedimentation with iron based coagulant, and chlorination of feed water for PVDF (Polyvinylidene fluoride) based MF membrane filtration. NaClO was fed to the membrane module at a dosage of 0.5 mg/L and maintained during filtration. To observe the effect of raw water, three types of raw and processed waters, including river surface water, coagulated water and coagulated-settled water, were employed. In the case of river surface water, the transmembrane pressure increased abruptly in 500 hours operation. On the contrary, no significant increase in transmembrane pressure was observed for coagulated water and coagulated-settled water for 1200 hours operation. The turbidity of permeate was lower than the detection limit for all applied waters. The removal efficiency for humic substances in coagulated water and coagulated-settled water was approximately ten times higher than that in surface river water. And, the removal efficiency for TOC and DOC was approximately two times higher than that in surface river water. From the results of the operation, it can be observed that it is possible to maintain stable operation at 0.9 m3/m2-day filtration flux through a combination of pre-coagulation and pre-chlorination. However, the water quality of permeate was the best when the pre-coagulation-sedimentation process was combined with pre-chlorination. With respect to fouling reduction and operation efficiency increase in membrane filtration, the pre-coagulation/sedimentation process is a promising alternative.
Behaviour of heavy metals during tertiary bio-filtration
Authors: Miska V. , Gorter K. , Menkveld H.W.H. , Neef R. , van der Graaf J.H.J.M.
Published: September 2006

More stringent water quality parameters in the Annex of the Water Framework Directive 2000/60/EC led to the introduction of “Maximum Tolerable Risk concentrations” (MTR-values) in the national legislation in The Netherlands (Vierde Nota Waterhuishouding). The MTR-values give limitations for the concentrations of e.g. heavy metals (HM's) but also for nutrients: Ntot <2.2 mg/l, Ptot <0.15 mg/l. Investigations of HM removal during denitrifying flocculation filtration are conducted on the effluent of a typical modern Dutch WWTP. Because of low concentrations of HM's in the feed water, a cocktail of copper, nickel and zinc chloride (≈150–200 μg/l) is dosed before filtration. Preliminary jar tests and filtration tests with media filtration in pilot-scale and lab-scale are conducted. The results show high removal of nickel and zinc during jar tests with dosing of powdered activated carbon. During filtration tests at pilot-scale the bounded fraction of copper and zinc is highly removed. All three HM's are removed in the lab-scale activated carbon filter. After dosing, nickel is found mainly in the dissolved form, but it is removed in the lab-scale activated carbon filter. The removal of HM's via adsorption subsequently leads to a discussion on the toxicity of HM's and their bio-availability.
Treatment of the butadiene washing stream from a synthetic rubber industry and recovery of p-TBC
Authors: Loss C.F. , Azevedo E.B. , Dezotti M.
Published: September 2006

Butadiene is marketed containing p-tertbutylcatechol (p-TBC), a polymerization inhibitor that should be removed before butadiene utilization in synthetic rubber production. p-TBC can be removed from butadiene by washing with sodium hydroxide (NaOH) solution, producing a wastewater with pH 14, which contains high amounts of p-TBC, a toxic chemical compound. The aim of this work was to develop a treatment process that could reduce the content of p-TBC from the wastewater. Since p-TBC is very soluble in basic, but not in neutral and acid solutions, acidification tests were performed with phosphoric acid (H3PO4) to precipitate p-TBC. Reaction between NaOH and H3PO4 can result in crystallization of large amounts of salt without p-TBC precipitation. Under selected acidifying conditions p-TBC precipitates and the wastewater COD is highly reduced (>90%). Chromatographic determinations showed that the precipitated p-TBC could be recovered with 99% purity.
Successful solution for high nitrogen content wastewater treatment from rendering plants
Authors: Auterská P. , Novák L.
Published: September 2006

Specific composition of wastewater from rendering plants requires a sophisticated approach to treatment. COD content up to 10 g/l and nitrogen up to 2.5 g/l leads to many difficulties during treatment with activated sludge process. Performance of such wastewater treatment plants is generally very unstable: severe problems with filamentous and viscous sludge bulking occur due to macronutrient deficiency, nitrification is often inhibited by high ammonia and nitrite content, no sufficient carbon source for denitrification is available, and high temperatures up to 40 °C negatively influence treatment processes. Appropriate control of pH, temperature, biocatalytic nutrient dosage, suitable external carbon source and restriction of inhibitory effects led to the successful operation of four wastewater treatment plants in the region reaching required effluent standards TIN=60 mg/l and COD=200 mg/l.
Comparative toxicity of nano-scale TiO2, SiO2 and ZnO water suspensions
Authors: Adams L.K. , Lyon D.Y. , McIntosh A. , Alvarez P.J.J.
Published: September 2006

TiO2, SiO2 and ZnO are common additives with improved applications at the nanoscale. The antibacterial activity of TiO2, which has important ecosystem health implications, is well understood. However, less attention has been paid to the antibacterial activity of SiO2 and ZnO despite them also producing reactive oxygen species. This paper explores the relative toxicity of TiO2, SiO2 and ZnO water suspensions towards bacteria (B. subtilis, E. coli) and the eukaryotic Daphnia magna. These three photosensitive nanomaterials were hazardous to all test organisms, with toxicity increasing with particle concentration. Toxicity of the three compounds decreased from ZnO to TiO2 to SiO2 and Daphnia were most susceptible to their effects. Nominal particle size did not affect the toxicity of these compounds. Antibacterial activity was noted under both dark and light conditions indicating that mechanisms additional to ROS production were responsible for growth inhibition. These results highlight the need for caution during the use and disposal of such manufactured nanomaterials to prevent unintended environmental impacts, as well as the importance of further research on the mechanisms and factors that increase toxicity to enhance risk management.
Geospeciation of arsenic using MINTEQA2 for a post-mining lake
Authors: Sari S.A. , Ujang Z. , Ahmad U.K.
Published: September 2006

The objective of this study was to investigate the cycling of arsenic in the water column of a post-mining lake. This study is part of a research project to develop health risk assessment for the surrounding population. Inductively Coupled Plasma-Mass Spectrophotometer (ICP-MS) and Capillary Electrophoresis (CE) have been used to analyze the total amount and speciation, respectively. A computer program, called MINTEQA2, which was developed by the United States Environmental Protection Agency (USEPA) was used for predicting arsenic, iron, and manganese as functions of pH and solubility. Studying the pH values and cycle of arsenic shows that the percentage of bound arsenate, As(V) species in the form of HAsO−4 increases with range pH from 5 to 7, as well as Fe(II) and Mn(II). As expected phases of arsenic oxides are FeAsO4 and Mn3(AsO4), as a function of solubility, however none of these phases are over saturated and not precipitated. It means that the phases of arsenic oxides have a high solubility.
Dynamic Evaluation of Matisse's 1935 Large Reclining Nude
Authors: Kozbelt Aaron
Published: September 2006

Forty non-artists and 16 art students rated the 22 in-progress states of Henri Matisse's great 1935 painting, Large Reclining Nude, on 26 survey items measuring several constructs: quality, originality, technique, arousal potential, and primordial thought. Factor analyses revealed differences in aesthetic judgment criteria consistent with previous research: non-artists value technique and realism, while art students emphasize originality. Changes in quality and other items were evident as the painting progressed. Non-artists judged the painting as getting generally worse over time, consistent with the increasing abstraction of the image. In contrast, art students' judgments showed a jagged trajectory with several peaks (including the finished version), suggesting an interactive hypothesis-testing process that gradually transformed the image.
Human versus Computer: The Effect of a Statement concerning a Musical Performance's Source on the Evaluation of its Quality and Expressivity
Authors: Ziv Naomi , Moran Ohad
Published: September 2006

The evaluation of the quality of a musical performance is not just a result of what we hear, but may be influenced by what we believe we hear. Ninety-six participants listened to two synthesized versions of a Chopin prelude, differing slightly in overall tempo, and were told that one version was played by a pianist, while the other was played by a computer. They evaluated the quality of the two versions, and rated the degree to which each version expresses various emotions. The “human” version was rated as a better performance, but no differences were found in degree and type of emotion expressed. It is suggested that attention was focused on different factors in answering the two types of questions.
Surface‐Enhanced Infrared Absorption Spectroscopy
Authors: Osawa Masatoshi
Published: September 2006

The sections in this article are

Introduction

Nature of Surface‐Enhanced Infrared Absorption

Enhancement Mechanisms

Electromagnetic Mechanism

Chemical Mechanisms

Experimental Procedures

Sample Preparation

Preparation of Surface‐Enhanced Infrared Absorption‐Active Metal Surfaces

Spectral Acquisition

Determination of Molecular Orientation

Applications

Analysis of Trace Chemicals

Biological Applications

Characterization of Thin Organic Films and Solid Surfaces

InsituStudy of Electrochemical Dynamics

Conclusion
Forced convection heat transfer from a sphere to non‐Newtonian power law fluids
Authors: Dhole S. D. , Chhabra R. P. , Eswaran V.
Published: September 2006

The effects of Reynolds number (Re), Prandtl number (Pr), and power law index (n) on the heat‐transfer characteristics of an unconfined sphere submerged in an isothermal and incompressible power law fluid, for different thermal boundary conditions (isothermal and isoflux) on the sphere surface, have been investigated numerically for the 2‐D axisymmetric and steady flow by using a finite volume method over the ranges of conditions as 5 ≤ Re ≤ 200, 1 ≤ Pr ≤ 400 (the maximum value of the Peclet number is 2000), and 0.5 ≤ n ≤ 2. Based on the numerical results obtained herein, simple heat‐transfer correlations are developed for the constant‐temperature and the constant heat‐flux boundary conditions to estimate the value of the Nusselt (Nu) number in a new application. Furthermore, the variation of the local Nu over the surface of the sphere has been studied to delineate the effects of Re, Pr, and n on heat transfer from a sphere, thereby showing the extent of heat transfer from the front and the rear parts of the sphere. © 2006 American Institute of Chemical Engineers AIChE J, 2006
4q35 deletion and 10p15 duplication associated with immunodeficiency
Authors: Cingoz S. , Bisgaard A.M. , Bache I. , Bryndorf T. , Kirchoff M. , Petersen W. , Ropers H.‐H. , Maas N. , Van Buggenhout G. , Tommerup N. , Tümer Z.
Published: September 2006

We report a familial cryptic reciprocal translocation between 4q35 and 10p15 leading to deletion of the terminal long arm of chromosome 4 and duplication of the terminal short arm of chromosome 10 in two family members who both have immunological disturbances and a similar facial appearance. The precise location and extent of the deletion and duplication was determined by fluorescence in situ hybridization (FISH). Furthermore, we investigated the deletion breakpoint of a previously reported patient with 4q34.3‐qter deletion [Van Buggenhout et al. (2004); Am J Med Genet Part A 131A:186–189]. © 2006 Wiley‐Liss, Inc.
Inheritance of sutural pattern at the pterion in rhesus monkey skulls
Authors: Wang Qian , Opperman Lynne A. , Havill Lorena M. , Carlson David S. , Dechow Paul C.
Published: September 2006

Five of the bones that characteristically comprise the cranial vault articulate on the lateral aspect of the skull at or near the cephalometric landmark referred to as the pterion. The pattern of articulation in the sutures associated with these bones varies among and within primate species and has been used as a criterion for classification in taxonomic studies, as well as in archeological and forensic studies. Within species, the sutural patterns found within the region of the pterion have remarkable consistency, which lead to the hypothesis that these patterns have a genetic basis. Sutural pattern variations were investigated at the pterion in 422 skulls from 66 rhesus monkey families with known genealogies from the long‐standing colony on Cayo Santiago. Four specific types of articulation patterns were recorded. The results demonstrated that the most common suture pattern at the pterion of Cayo Santiago rhesus monkeys (86%; similar to that seen in some other anthropoid species but not humans and some apes) was characterized by an articulation between the temporal bone and parietal bone. Articulation between the sphenoid and parietal bones (type SP) accounted for 14% of the specimens and was concentrated in a dozen families. Mothers with the SP phenotype had a high incidence of offspring with SP phenotypes. Most non‐SP mothers having SP offspring had siblings or family members from previous generations with the SP type. This is the first study to examine variation in sutural patterns at the pterion in pedigrees. Variation of sutural patterns shows familial aggregation, suggesting that this variation is heritable. Future work will be focused on defining the inheritance patterns of variation at the pterion, with the ultimate objective of identifying the specific genes involved and their mechanism of action. Anat Rec Part A, 288A:1042–1049, 2006. © 2006 Wiley‐Liss, Inc.
Tuning the Formation of Cadmium(II) Urocanate Frameworks by Control of Reaction Conditions: Crystal Structure, Properties, and Theoretical Investigation
Authors: Zou Ru‐Qiang , Zhong Rui‐Qin , Jiang Ling , Yamada Yusuke , Kuriyama Nobuhiro , Xu Qiang
Published: September 2006

The reaction of cadmium(II) perchlorate with urocanic acid under different conditions created three novel coordination compounds: [Cd2(L2)2‐(L3)2(H2O)8] (1), {[Cd(L)(L2)](H2O)1/2}n (2), and {[Cd(L3)2](H2O)3/2(EtOH)}n (3), in which L, L2, and L3 are three urocanate tautomers. Complex 1 consists of two separate mononuclear units with different urocanate tautomers, which self‐assemble into a 3D hydrogen‐bonding network constructed by alternating 2D layers, whereas complexes 2 and 3 self‐assemble into 3D alpha‐polonium and four‐fold interpenetrated diamondoid networks, respectively. The tautomerism of the urocanate ligands and the enormous structural diversity of their complexes are present in this system, which illustrates that the reaction temperature, pressure, and the metal ions themselves act cooperatively to tune the tautomerism of the ligands and the frameworks of their metal coordination compounds. The fluorescence‐emission and nitrogen‐adsorption properties of these complexes are also investigated.