bluuebunny/crossref_metadata_2025 huggingface dataset:
Simple wastewater treatment (UASB reactor, shallow polishing ponds, coarse rock filter) allowing compliance with different reuse criteria
Authors: von Sperling M. , de Andrada J.G.B.
Published: September 2006

UASB reactors followed by polishing ponds comprise simple and economic wastewater treatment systems, capable of reaching very high removal efficiencies of pathogenic organisms, leading to the potential use of the effluent for unrestricted irrigation. However, for other types of reuse (urban and industrial), ponds are limited in the sense of producing effluents with high suspended solids (algae) concentrations. The work investigates a system with coarse rock filters for polishing the pond effluent. The overall performance of the system is analyzed, together with the potential for different types of reuse. The excellent results obtained (mean effluent concentrations: BOD: 27 mg/L; SS: 26 mg/L; E. coli: 450 MPN/100 mL) indicate the possibility of unrestricted use of the effluent for agriculture and restricted urban and industrial uses, according to WHO and USEPA.
Simultaneous removal of ammonium-nitrogen and sulphate from wastewaters with an anaerobic attached-growth bioreactor
Authors: Zhao Q.-l. , Li W. , You S.-j.
Published: September 2006

Some industrial wastewaters may contain ammonium-nitrogen and/or sulphate, which need to be removed before their discharge into natural water bodies to eliminate their severe pollution. In this paper, simultaneous removal of ammonium-nitrogen and sulphate with an anaerobic attached-growth bioreactor of 3.8 L incubated with sulphate reducing bacteria (SRB) was investigated. Artificial wastewater containing sodium sulphate as electron acceptor, ammonium chlorine as electron donor and glucose as carbon source for bacteria growth was used as the feed for the bioreactor. The loading rates of ammonium-nitrogen, sulphate and COD were 2.08 gN/m3·d, 2.38 gS/m3·d, 104.17 gCOD/m3·d, respectively, with a N/S ratio of 1:1.14. The results demonstrated that removal rates of ammonium-nitrogen, sulphate and COD could reach 43.35%, 58.74% and 91.34%, respectively. Meanwhile, sulphur production was observed in effluent as well as molecular nitrogen in biogas, whose amounts increased with time substantially, suggesting the occurrence of simultaneous removal of ammonium-nitrogen and sulphate. This novel reaction provided the possibility to eliminate ammonium-nitrogen and sulphate simultaneously with accomplishment of COD removal from wastewater, making wastewater treatment more economical and sustainable.
Tracking influent inorganic suspended solids through wastewater treatment plants
Authors: Ekama G.A. , Wentzel M.C. , Sötemann S.W.
Published: September 2006

From an experimental and theoretical investigation of the continuity of influent inorganic suspended solids (ISS) along the links connecting the primary settling tank (PST), fully aerobic or N removal activated sludge (AS) and anaerobic and aerobic sludge digestion unit operations, it was found that the influent wastewater (fixed) ISS concentration is conserved through primary sludge anaerobic digestion, activated sludge and aerobic digestion unit operations. However, the measured ISS flux at different stages through a series of wastewater treatment plant (WWTP) unit operations is not equal to the influent ISS flux, because the ordinary heterotrophic organisms (OHO) biomass contributes to the ISS flux by differing amounts depending on the active fraction of the VSS solids at that stage.
Olive mill wastewater treatment: an experimental study
Authors: Bettazzi E. , Morelli M. , Caffaz S. , Caretti C. , Azzari E. , Lubello C.
Published: September 2006

Olive oil production, one of the main agro-industries in Mediterranean countries, generates significant amounts of olive mill wastewaters (OMWs), which represent a serious environmental problem, because of their high organic load, the acidic pH and the presence of recalcitrant and toxic substances such as phenolic and lipidic compounds (up to several grams per litre). In Italy, traditional disposal on the soil is the most common way to discharge OMWs. This work is aimed at investigating the efficiency and feasibility of AOPs and biological processes for OMW treatment. Trials have been carried out on wastewaters taken from one of the largest three-phase mills of Italy, located in Quarrata (Tuscany), as well as on synthetic solutions. Ozone and Fenton's reagents applied both on OMWs and on phenolic synthetic solutions guaranteed polyphenol removal efficiency up to 95%. Aerobic biological treatment was performed in a batch reactor filled with raw OMWs (pH =4.5, T=30 °C) without biomass inoculum. A biomass rich of fungi, developed after about 30 days, was able to biodegrade phenolic compounds reaching a removal efficiency of 70%. Pretreatment of OMWs by means of oxidation increased their biological treatability.
Pb(II) biosorption on reed biosorbent derived from wetland: effect of pretreatment on functional groups
Authors: Southichak B. , Nakano K. , Nomura M. , Chiba N. , Nishimura O.
Published: September 2006

Reed biomass harvested from wetland constructed for water purification was modified into a biosorbent for Pb(II) removal from aqueous solution. The enhancement of Pb(II) adsorption by reed biosorbent depended not only on the types of reagent used for pretreatment, but also on the pH during the pretreatment process. The mechanisms, as elucidated using relational data obtained from Boehm titration, Fisher esterification and FTIR, involved the conversion of carboxylic groups into carboxylate groups, and proved the role of the carboxylate group, which occupied more than 80% in binding Pb(II). The Langmuir sorption isotherm of Pb(II) by R-NaOH-12 showed Qmax and b values of 0.082 mmol/g and 312.5 g/mmol, suggesting enough adsorption performance to reduce the concentration of Pb(II) to meet the range of WHO guidelines. The salinity of aqueous solution containing NaH2PO4 and NaNO3 promoted the adsorption of Pb(II), while NaCl and Na2SO4 suppressed the adsorption capacity of Pb(II). The adsorption mechanism of reed biosorbent provides valuable insight on the pretreatment effects and the advantages of utilizing this plant as biosorbent for Pb(II) and other heavy metals.
Anaerobic treatment of organic chemical wastewater using packed bed reactors
Authors: Mijaylova-Nacheva P. , Peña-Loera B. , Cuevas-Velasco S.
Published: September 2006

The studied organic chemical wastewater had a high COD, 20–45 g/L, and low TSS, less than 200 mg/L, making anaerobic bio-filtration a suitable treatment method. The organic matter consisted of alcohols, amines, ketones and aromatic compounds, such as toluene and phenol. Granulated activated carbon (GAC) and a porous stone called tezontle, widely available in Mexico, were used as a bio-film support. Once inoculated, the mesophilic reactors with granulated activated carbon (GAC-BFs) reached stability with 80% COD removal in 40 days, while the reactors with tezontle material (tezontle-BF) required 145 days. Biodegradation of more than 95% was obtained with both support media: at organic loads less than 1.7 kg m−3 d−1 in tezontle-BF and with loads of up to 13.3 kg m−3 d−1 in GAC-BFs. The bio-filters with GAC allowed COD removal efficiency of 80% at a load as high as 26.3 kg m−3 d−1, while the same efficiency with tezontle was obtained at loads up to 4.45 kg m−3 d−1. The use of GAC as support material allows greater biodegradation rates than tezontle and it makes the bio-filters more resistant to organic increases, inhibition effects and toxicity. Methanogenic activity was inhibited at loads higher than 1.7 kg m−3 d−1 in bio-filters with tezontle and 22.8 kg m−3 d−1 in bio-filters with GAC. At loads lower than the previously mentioned, high methane production yield was obtained, 0.32–0.35 m3CH4/kg CODremoved. The biomass growth rates were low in the bio-filters with both kinds of material; however, a sufficiently high biomass holdup was obtained.
A comparison of continuous flow and sequencing batch reactor plants concerning integrated operation of sewer systems and wastewater treatment plants
Authors: Simon J. , Wiese J. , Steinmetz H.
Published: September 2006

Integrated operation strategies for combined sewer and WWTP are becoming more and more popular because of numerous benefits. One can find many examples in literature, but many of these studies deal with partly fictitious systems and/or were accomplished within the planning. Hence most of these studies do not have to deal with the restrictions given by already built constructions. The authors, who worked on several integrated projects, will discuss the requirements of SBR and CFR plants concerning an implementation of integrated operation.
An inventory analysis of rural pollution loads in China
Authors: Chen M. , Chen J. , Du P.
Published: September 2006

Rural pollution has attracted increasing attention over the past decade for its important consequences on surface and groundwater quality. This is particularly so in China due to the wide and effective control of industrial and municipal wastewater discharges over the past decade. Based on the discussion of rural activities in China, this paper develops a new method of inventory analysis through the definition of elementary unit (EU). This inventory analysis approach is then applied to estimate the total rural pollution loads of COD, TN and TP, as well as their spatial distributions in China. Further analysis is also conducted to investigate the correlations between rural pollution loads and agricultural production outputs, as well as population. It is found that China's agriculture is developing largely at the cost of environment quality, and a high population, as well as the increasing demand for agricultural products, is one of the dominant driving forces. The constructed EKC, which describes the relationship between rural pollution loads and agricultural income, also reveals that current agricultural development in China is mostly far from de-locked from the environmental problem.
Prediction of flood abnormalities for improved public safety using a modified adaptive neuro-fuzzy inference system
Authors: Aqil M. , Kita I. , Yano A. , Nishiyama S.
Published: September 2006

It is widely accepted that an efficient flood alarm system may significantly improve public safety and mitigate economical damages caused by inundations. In this paper, a modified adaptive neuro-fuzzy system is proposed to modify the traditional neuro-fuzzy model. This new method employs a rule-correction based algorithm to replace the error back propagation algorithm that is employed by the traditional neuro-fuzzy method in backward pass calculation. The final value obtained during the backward pass calculation using the rule-correction algorithm is then considered as a mapping function of the learning mechanism of the modified neuro-fuzzy system. Effectiveness of the proposed identification technique is demonstrated through a simulation study on the flood series of the Citarum River in Indonesia. The first four-year data (1987 to 1990) was used for model training/calibration, while the other remaining data (1991 to 2002) was used for testing the model. The number of antecedent flows that should be included in the input variables was determined by two statistical methods, i.e. autocorrelation and partial autocorrelation between the variables. Performance accuracy of the model was evaluated in terms of two statistical indices, i.e. mean average percentage error and root mean square error. The algorithm was developed in a decision support system environment in order to enable users to process the data. The decision support system is found to be useful due to its interactive nature, flexibility in approach, and evolving graphical features, and can be adopted for any similar situation to predict the streamflow. The main data processing includes gauging station selection, input generation, lead-time selection/generation, and length of prediction. This program enables users to process the flood data, to train/test the model using various input options, and to visualize results. The program code consists of a set of files, which can be modified as well to match other purposes. This program may also serve as a tool for real-time flood monitoring and process control. The results indicate that the modified neuro-fuzzy model applied to the flood prediction seems to have reached encouraging results for the river basin under examination. The comparison of the modified neuro-fuzzy predictions with the observed data was satisfactory, where the error resulted from the testing period was varied between 2.632% and 5.560%. Thus, this program may also serve as a tool for real-time flood monitoring and process control.
Effects of effluent recirculation in vertical-flow constructed wetland on treatment efficiency of livestock wastewater
Authors: Lian-sheng He , Hong-liang Liu , Bei-dou Xi , Ying-bo Zhu
Published: September 2006

Enhancing the treatment efficiency of livestock wastewater by effluent recirculation is investigated in a pilot-scale vertical-flow constructed wetland. The wetland system is composed of downflow and upflow stages, on which narrow-leaf Phragmites communis and common reed Phragmites typhia are planted, respectively; each stage has a dimension of 4 m2 (2 m×2 m). Wastewater from the facultative pond is fed into the system intermittently at a flow rate of 0.4 m3/d. Recirculation rates of 0, 25%, 50%, 100% and 150% are adopted to evaluate the effect of the recirculation rate on pollutants removal. This shows that with effluent recirculation the average removal efficiencies of NH4-N, BOD5 and SS obviously increase to 61.7%, 81.3%, and 77.1%, respectively, in comparison with the values of 35.6%, 50.2%, and 49.3% without effluent recirculation. But the improvement of TP removal is slight, only from 42.3% to 48.9%. The variations of NH4-N, DO and oxidation–reduction potential (ORP) of inflow and outflow reveal that the adoption of effluent recirculation is beneficial to the formation of oxide environment in wetland. The exponential relationships with excellent correlation coefficients (R2>0.93) are found between the removal rates of NH4-N and BOD5 and the recirculation rates. With recirculation the pH value of the outflow decreases as the alkalinity is consumed by the gradually enhanced nitrification process. When recirculation rate is kept constant at 100%, the ambient temperature appears to affect NH4-N removal, but does not have significant influence on BOD5 removal.
Nitrogen mass balance and microbial analysis of constructed wetlands treating municipal landfill leachate
Authors: Polprasert C. , Sawaittayothin V.
Published: September 2006

Experiments were conducted to investigate the feasibility of applying constructed wetlands (CW) to treat a sanitary landfill leachate containing high nitrogen (TN) and bacterial contents. Under the tropical conditions (temperature of about 30 °C), the CW units operating at a hydraulic retention time (HRT) of 8 days yielded the best treatment efficiencies with BOD5 removal of 91%, TN removal of 96%, total and fecal coliforms (TC and FC) removal of more than 99%. Cadmium removal in the in the SFCW bed was found to be 99.7%. Mass balance analysis, based on TN contents of the plant biomass and dissolved oxygen (DO) and oxidation - reduction potential (ORP) values, suggested that 88% of the input TN were uptaken by the plant biomass. Fluorescence in situ hybridization (FISH) results revealed the predominance of bacteria including the heterotrophic and autotrophic bacteria responsible for BOD5 removal. Nitrifying bacteria was not found to be present in the SSFCW beds.
Ammonia recovery from anaerobically digested cattle manure by steam stripping
Authors: Zeng L. , Mangan C. , Li X.
Published: September 2006

Ammonia recovery from anaerobically digested cattle manure effluents through steam stripping was studied at a stripping tower temperature of 98–99 °C and a steam–water ratio approximately 56–72 g/L. The digested manure effluents were first treated by microfiltration and then the permeate was used as feed in steam stripping. The stripping performance was evaluated under different feed pH values, ammonia concentrations and temperatures. The increase of the initial feed pH does not significantly improve ammonia stripping efficiency due to the fact that the stripped effluent pH is increased during steam stripping. This suggests that steam stripping of anaerobically digested manure effluents for ammonia recovery may not need pre-raised pH. In contrast, the pH value of the synthetic ammonia wastewater containing NH4Cl dramatically decreases after steam stripping. Increasing the feed temperature slightly improves ammonia stripping efficiency, but reduces the concentration of the recovered ammonia in the condensate due to an increased condensate volume at a higher feed temperature. Therefore, the feed temperature should be controlled at an optimum point that can compromise the condensate ammonia concentration and the ammonia stripping efficiency. Experimental results indicate that recovery of ammonia from anaerobically digested cattle manure effluents as NH4OH is technically feasible.
Resource recovery and nitrogen removal from piggery waste using the combined anaerobic processes
Authors: Hwang I.S. , Min K.S. , Choi E. , Yun Z.
Published: September 2006

The combined ADEPT (Anaerobic Digestion Elutriated Phased Treatment)- SHARON (Single reactor system High Ammonium Removal Over Nitrite) – ANAMMOX (Anaerobic Ammonium Oxidation) processes were operated for the purpose of resource recovery and nitrogen removal from slurry-type piggery waste. The ADEPT operated at acidogenic loading rates of 3.95 gSCOD/L-day, the SCOD elutriation rate and acid production rate were 5.3 gSCOD/L-day and 3.3 gVFAs(as COD)/L-day, respectively. VS reduction and SCOD reduction by hydrolysis were 13% and 0.19 gSCODprod./gVSfeeding, respectively. Also, the acid production rate was 0.80 gVFAs/gSCODproduction. In the methanogenic reactor, the gas production rate and methane content were 2.8 L/day (0.3 m3CH4/kgCODremoval@STP) and 77%, respectively. With these operating condition, the removal of nitrogen and phosphorus were 94.1% as NH4-N (86.5% as TKN) and 87.3% as T-P, respectively.
Application of a combined process of moving-bed biofilm reactor (MBBR) and chemical coagulation for dyeing wastewater treatment
Authors: Shin D.H. , Shin W.S. , Kim Y.-H. , Ho Han Myung , Choi S.J.
Published: September 2006

A combined process consisted of a Moving-Bed Biofilm Reactor (MBBR) and chemical coagulation was investigated for textile wastewater treatment. The pilot scale MBBR system is composed of three MBBRs (anaerobic, aerobic-1 and aerobic-2 in series), each reactor was filled with 20% (v/v) of polyurethane-activated carbon (PU-AC) carrier for biological treatment followed by chemical coagulation with FeCl2.In the MBBR process, 85% of COD and 70% of color (influent COD=807.5 mg/L and color=3,400 PtCo unit) were removed using relatively low MLSS concentration and short hydraulic retention time (HRT=44 hr). The biologically treated dyeing wastewater was subjected to chemical coagulation. After coagulation with FeCl2, 95% of COD and 97% of color were removed overall. The combined process of MBBR and chemical coagulation has promising potential for dyeing wastewater treatment.
Population dynamics of anaerobic microbial consortia in thermophilic methanogenic sludge treating paper-containing solid waste
Authors: Tatsuzawa T. , Hao L. , Ayame S. , Shimomura T. , Kataoka N. , Miya A.
Published: September 2006

To maintain a stable thermophilic (55 °C) anaerobic digestion treating toilet paper-containing garbage, it is necessary to operate the digester at long hydraulic retention time (HRT) and low organic loading rate (OLR). Critical conditions of the digestion were investigated by operating the digester at HRT 23 days and OLR 3.4 gCODCr/L/d (R1) or HRT 14 days and OLR 5.6 gCODCr/L/d (R2) separately. Characteristics of methanogenesis of the two digesters were examined by measuring gas generation volume and volatile fatty acids (VFA) concentration, and the populations of four anaerobic acidogens and three methanogens were analyzed using quantitative PCR method. In digester R1, methanogenic activity was unstable but it could be recovered by stopping feeding as though VFA accumulation occurred. The population of acidogens and two methanogens were maintained at 1011–1013 copies/L, however, the population of Methanoculleus could not be recovered after methanogenesis recovering. In digester R2, the period of methanogenesis was significantly shorter than that in digester R1. Both the acidogens and the methanogens could not be maintained at a stable concentration. It is suggested that the critical HRT to sustain the population of acidogens in this process should be longer than 14 days and for all kinds of methanogens, HRT should be longer than 23 days.
Solid mining residues from Ni extraction applied as nutrients supplier to anaerobic process: optimal dose approach through Taguchi's methodology
Authors: Pereda I. , Irusta R. , Montalvo S. , del Valle J.L.
Published: September 2006

The use of solid mining residues (Cola) which contain a certain amount of Ni, Fe and Co, to stimulate anaerobic processes was evaluated. The effect over methane production and chemical oxygen demand (COD) removal efficiency was analysed. The studies were carried out in discontinuous reactors at lab scale under mesophilic conditions until exhausted. 0, 3, 5 and 7 mgCola l−1 doses were applied to synthetic wastewater. Volatile fatty acids (VFA) and sucrose were used as substrate, sulphur and nitrogen concentration, being the noise variable. Cola addition at dose around 5 mg l−1, turned out to be stimulating for the anaerobic process. It was the factor that most influenced on methane production rate together with VFA and high content of volatile suspended solids. In the case of methane yield, pH was the control factor of strongest influence. Higher values of COD removal efficiency were obtained when the reactors were operated with sucrose at relatively low pH and at the smallest concentration of nitrogen and sulphur. Solid residues dose and the type of substrate were the factors that had most influence on COD removal efficiency.
Extracellular polymers in partly ozonated return activated sludge: impact on flocculation and dewaterability
Authors: Dytczak M.A. , Londry K. , Siegrist H. , Oleszkiewicz J.A.
Published: September 2006

The purpose of this study was to evaluate the influence of partial ozonation of return activated sludge on settling properties and dewaterability of sludge. Sequencing batch reactors with two sets of aerobic and alternating anoxic/aerobic conditions were used. In each set, one reactor served as a control and the other was subject to the ozone treatment (doses in the range of 0.016–0.080 mg O3/mg TSS of initial excess sludge). The level of total suspended solids (TSS) in each reactor was controlled at 1,800 mg/l. To evaluate settleability and dewaterability, settling kinetic studies, sludge volume index (SVI) and capillary suction time test (CST) were used. For extraction and quantifying sludge biopolymers, thermal-ethanolic extraction was employed. The ratio of bound-to-total extracellular polymer substances (EPS) was higher for the strictly aerobic reactor than for the alternating anoxic/aerobic one, indicating the stronger structure of the aerobic flocs. After ozone treatment, the fraction of bound EPS was released and solubilized, increasing soluble EPS. Increased apparent food-to-microorganism (F/M) ratio favoured production of EPS in ozonated reactors, enhancing flocculation, which had potential to improve settling. Dewaterability, measured by CST test, was better in alternating anoxic/aerobic reactors than in aerobic ones, indicating that incorporation of an anoxic zone for biological nutrient removal leads to improvement in sludge dewatering. The negative impact of ozonation on dewaterability was minimal in terms of the long-term operation.
Optimal performance of an immersed membrane bioreactor equipped with a draft tube for domestic wastewater reclamation
Authors: Yang F. , Bick A. , Shandalov S. , Oron G.
Published: September 2006

One of the options to prevent membrane fouling is to implement air lifting that can improve the cake removal from the membrane surface. This study presents the results of tests that were carried out at the Institutes for Desert Research, Kiryat Sde-Boker, Israel, and focused on the influence of hydrodynamic conditions on fouling in a pilot-scale immersed membrane bioreactor (IMBR) using a hollow fiber membrane module of ZW-10 (Zenon Environmental, Canada) under ambient conditions. In this system, the cross-flow velocities across the membrane surface were induced by one conical and four cylindrical draft-tubes. The relationship between the crossflow velocity and the aeration intensity, the influence of the crossflow on fouling rate under various hydrodynamic conditions were investigated and optimal operating conditions were obtained. Optimal operating conditions were reached during the long-term experiment period (70 days) for the treatment of domestic wastewater. The system was stable without external chemical cleaning. The results showed that the permeate was of high quality, and the removal of COD and BOD was 94.0% and 98.8%, respectively.The crossflow near the membrane surface reveals a major contribution for minimizing membrane fouling, and could offer guidelines for future design of similar systems.
Anaerobic biodegradation of chlorinated aliphatic compounds using packed bed reactors
Authors: Mijaylova-Nacheva P. , Canul-Chuil A.
Published: September 2006

The feasibility of anaerobic packed bed reactors with tezontle (volcanic stone widely available in Mexico) and mineral granular activated carbon (GAC) was explored for the degradation of the main chlorinated aliphatic compounds present in the effluent from chemical industry for ethylene and polyvinyl chloride production. The biofilm on the support materials was developed using as inoculums anaerobic sludge. The biodegradation of the halogenated aliphatic compounds (1,2-dichloroethane; 1,1,1-trichloroethane; trichloroethylene and carbon tetrachloride) was possible without addition of external electron donors. High COD removal was obtained in the reactors with both materials. The use of GAC as a biomass support allows a complete biodegradation of the chlorinated aliphatic compounds at organic loads up to 1.24 kgCOD.m−3.d−1, with 94% of COD removal and with a biodegradation rate of 2.062 gCOD.kgGAC−1.d−1. The reactor with tezontle also had high biodegradation capacity, but the biodegradation of the 1,1-dichloroethene, which appeared as intermediate product, was not reached at the required level in the studied range of organic loads.
Closing the water loop in a maltery: reuse tests at pilot-scale
Authors: De Wever H. , Boënne W. , Danau M. , Vanderspiegel N. , Hardy K. , Limbos J.
Published: September 2006

This paper reports on the potential for water reuse in the malting sector. Core unit of a treatment train to close the water loop was a membrane bioreactor (MBR). We compared three different commercial submerged membranes for their fouling potential in this application and related this to the presence of extracellular polymeric substances (EPS). In a second step, we subjected MBR permeate to reverse osmosis and several (advanced) oxidation processes to evaluate the water quality achieved. Finally we performed a set of water reuse tests with waters obtained through different scenarios. The optimal scenario was then tested in a closed water loop over several malting cycles at pilot scale and the effect on water and malt quality was investigated.
Seasonal profiles of human noroviruses and indicator bacteria in a wastewater treatment plant in Tokyo, Japan
Authors: Haramoto E. , Katayama H. , Oguma K. , Yamashita H. , Tajima A. , Nakajima H. , Ohgaki S.
Published: September 2006

The seasonal profiles of microorganisms in raw sewage, secondary-treated sewage, and final effluent at a wastewater treatment plant in Tokyo, Japan, were quantitatively determined each month for one year, from July 2003 to June 2004. Human noroviruses, which were determined by real-time PCR, in raw sewage varied from 0.17–260 copies/mL for genotype 1 and from 2.4–1900 copies/mL for genotype 2, showing much higher values in winter, the epidemic season. The concentration of total coliforms, Escherichia coli, or F-specific phages in raw sewage was almost constant throughout the year. Human noroviruses of genotype 2 were removed most effectively (3.69 log10 on average) at the wastewater treatment plant, followed by E. coli (3.37 log10), total coliforms (3.05 log10), F-specific phages (2.81 log10), and human noroviruses of genotype 1 (2.27 log10). The removal ratio of human noroviruses was almost constant, independent of the initial concentration of the viruses in raw sewage, which led to the increasing concentration of human noroviruses in final effluent in winter. None of the tested bacteria was judged to be a reliable indicator of human noroviruses in final effluent.
Microbiological quality of groundwater sources used by rural communities in Limpopo Province, South Africa
Authors: Potgieter N. , Mudau L.S. , Maluleke F.R.S.
Published: September 2006

A survey of the microbiological quality of water from 194 boreholes (97 privately owned and 97 communal boreholes) in the rural Thitale-Hlanganani area of the Limpopo Province, South Africa was carried out between August 2002 and August 2003. Very little information on the microbiological quality of privately-owned boreholes in rural communities is available raising concerns about the safety of these groundwater supplies. In this study, levels of total coliforms, thermotolerant (faecal) coliforms, faecal enterococci, Clostridium perfringens (vegetative cells and spores) and somatic coliphages were determined for community and privately-owned borehole water. The average counts for total coliforms, faecal coliforms, faecal enterococci and Clostridium perfringens exceeded the South African recommended guideline limits of 0–10 counts.100 ml−1 for total coliforms and 0 counts.100 ml−1 for faecal coliforms, faecal enterococci and Clostridium perfringens respectively. Comparisons between the levels of indicator bacteria present in private and communal boreholes during dry seasons indicated a statistical difference for faecal enterococci bacteria (p=0.005) and Clostridium perfringens (p=0.08). Comparisons between the levels of indicator bacteria present in private and communal boreholes during rainy seasons indicated statistical differences between total coliforms (p=0.05), faecal coliforms (p=0.03) and Clostridium perfringens (p=0.009) bacteria. No significant differences in the presence of somatic coliphages in both private and communal borehole water were see. The results indicated the need for environmental impact assessment studies to monitor the microbiological quality of groundwater sources in rural communities.
Transport of antibiotic-resistant bacteria and resistance-carrying plasmids through porous media
Authors: Rysz M. , Alvarez P.J.J.
Published: September 2006

Microbial antibiotic resistance has emerged as not only a major medical problem but also as an environmental engineering challenge, with antibiotic resistance genetic elements as environmental pollutants. The transport characteristics of a tetracycline-resistant bacterium (B. cepacia) and plasmids carrying tetracycline-resistance genes were investigated using flow-through columns packed with porous media. Higher influent cell concentrations (1.1×108 CFU mL−1) resulted in higher breakthrough (C/C0=0.596±0.055) than a solution with lower cell concentration (2.0×106 CFU mL−1, C/C0=0.461±0.037). This decreased extent of filtration suggests fast initial cell deposition and strong subsequent blocking of binding sites, resulting in less-hindered microbial transport through the sandy medium. The addition of a bromide tracer (NaBr) prior to the plasmid solution resulted in DNA retardation and increased filtration in a zirconia-silica bead matrix. Apparently, Na+ binding to the beads decreased electrostatic repulsion between the negatively charged DNA and zirconia-silica surface. In contrast, plasmid breakthrough preceded that of the tracer when the plasmids were added first, possibly due to size exclusion chromatography coupled with stronger electrostatic repulsion. This implies that efforts to characterize the dynamics of resistance vector propagation in aquifers should consider the effect of groundwater chemistry and the surface characteristics of the porous media on vector transport.
The Historical Development of Experimental Techniques in Vibrational Spectroscopy
Authors: Sheppard Norman
Published: September 2006

The sections in this article are

Introduction

The Laying of the Foundations: the Period to 1945

Infrared Spectroscopy: the Development of Experimental Techniques

The Origins and Interpretation of Infrared Spectra

Applications of Infrared Spectroscopy

Atmospheric Studies

Blackbody Radiation and Quantum Theory

High‐Resolution Vibration–Rotation Spectra

Molecular Structure Analysis by Vibrational Spectroscopy

TheRaman Effect and Its Applications

The Period, since 1945, of Multiple Applications of the Infrared andRaman Spectroscopies

The Evolution of Commercial Infrared Spectrometers

Dispersion Spectrometers

Infrared Interferometers; theFourier‐Transform Revolution

Tunable Lasers as Infrared Sources

Near‐Infrared Spectroscopy

Far‐Infrared Spectroscopy

Additional Experimental and Theoretical Techniques in Infrared Spectroscopy and their Applications

Attenuated Total (Internal) Reflection

Depth Profiling of Samples

Detectors

Diamond Anvil (High‐Pressure) Cell

Diffuse Reflection Spectroscopy

Digitization of Spectra

Emission Spectroscopy

Gas Chromatography

Infrared Microscopy

Long‐Pathlength Gas Cells

KBrDisks

Low‐Temperature Matrix Isolation

Nujol Mulls

Photoacoustic Spectroscopy

Polarization and Polarization‐Modulation Spectroscopy

Quantum‐Mechanical Calculations of Vibrational Spectra

Reflection Spectroscopy

Reflection‐Absorption Infrared Spectroscopy and the Metal–Surface Selection Rule

Sum Frequency Generation

Surface Spectroscopy

Vibrational Circular Dichroism Spectroscopy

TheRaman Spectroscopies from 1945

Raman Spectroscopy

ResonanceRaman Spectroscopy

Coherent Anti‐StokesRaman Spectroscopy(CARS)

Hyper‐Raman Spectroscopy

InverseRaman Spectroscopy

StimulatedRaman Effect

Additional Techniques inRaman Spectroscopy and their Applications

Raman Optical Activity

Optical Fiber Sampling

SurfaceRaman Spectroscopy

Surface‐EnhancedRaman Spectra

The Newer Vibrational Spectroscopies

High‐Resolution Electron Energy Loss Spectroscopy

Inelastic Electron Tunneling Spectroscopy

Inelastic Neutron Scattering

Inelastic Molecular Beam Scattering

Epilog

Biomolecular Spectroscopy

Crystal Spectra

Double‐Minima Spectroscopic Phenomena

Hydrogen Bonding and Intermolecular Interactions

Inorganic Spectroscopy

Intensities in Vibrational Spectra

Internal Rotation within Molecules: Conformational (Rotational) Isomerism

Molecular Force Fields and Vibration Frequencies

Conclusion

Acknowledgments
Infrared Spectroscopy: Theory
Authors: Steele Derek
Published: September 2006

The sections in this article are

Introduction

Factors that Control Absorption

The Effects of Symmetry on Molecular Vibrations

Quantization and Anharmonicity in Real Vibrating Molecules

Intensities of Absorption

Band Shapes in Liquids

Calculation of Vibrational Spectra

Revisiting the Ethyne Spectrum

Product Rule

Sum Rule

Quantum‐Theoretical Calculations of Spectra

Vibration–Rotation Spectra

Appendix 1
Raman Spectroscopy of the Condensed Phase
Authors: Everall Neil J.
Published: September 2006

This article discusses the general factors that influence the appearance of Raman spectra of materials in the condensed phase. The same material, when presented in different physical forms, can have significantly different Raman spectra. This must be taken into account when interpreting condensed phase spectra. After considering the main differences between the spectra of gases and liquids or solids, some effects peculiar to the solid state are discussed in detail. The influence of site and factor group splitting and phonon dispersion is described, as are the practical consequences of polymorphism. The effects of crystal and particle size, lattice defects, and the presence of amorphous domains are discussed, as is the influence of molecular orientation in crystals or drawn polymers. Finally, some artefacts that are prone to occur with condensed phase samples (self‐absorption of radiation, fluorescence, and degradation) are mentioned along with ways to minimise their impact.
Miniature Spectrometers
Authors: Kruzelecky Roman V. , Ghosh Asoke K.
Published: September 2006

The sections in this article are

Introduction

Review of Fabrication Technologies for Miniature Spectrometers

Slab Waveguide Spectrometers

Micromachining of Spectrometer Optics

Injection‐Molded Spectrometers

Miniature Bulk‐Optic Spectrometers

The Optics of Miniature Spectrometers

Performance Considerations

Optical Layout

Input Optics

Spectral Dispersion and Resolution

Output Focal Plane and Imaging

Linear Detector Arrays

Review of the Performance of Miniature Spectrometers

Applications of Miniature Spectrometers

Conclusions

Acknowledgments
Polarization Interferometers for Infrared Spectrometry
Authors: Polavarapu Prasad L.
Published: September 2006

Principles and applications of interferometers based on polarization division of incoming light are described in this article. The applications of interferometers include polarization division of incoming light using either a Wollaston prism or a wiregrid beamsplitter. The interferometers with wiregrid beam splitters utilizing flat mirrors are referred to as polarizing Michelson interferometers; those utilizing roof‐top mirrors are referred to as Martin–Puplett interferometers; and those utilizing cube corner mirrors are referred to as polarization division interferometers with cube corner mirrors. There are distinct advantages offered by each of these interferometers, which hopefully will renew interest in developing commercial products.
Time‐Resolved Mid‐Infrared Spectrometry Using an Asynchronous
F
ourier Transform Infrared Spectrometer
Authors: Masutani Koji
Published: September 2006

A novel asynchronous time‐resolved Fourier transform infrared (FT‐IR) spectrophotometer based on a conventional continuous‐scan interferometer for repetitive phenomenon is introduced. In contrast to the others, this method does not require the synchronization between the signal for time resolving and that for the sampling of the analog‐to‐digital (A/D) converter. The signal‐processing assembly for time‐resolved measurements consists of a pulse generator, a pulse delay circuit, a gate circuit, and a low‐pass filter. This assembly can be attached to any conventional FT‐IR spectrophotometer. Furthermore, the system with the plural assemblies enables to measure a set of time‐resolved spectra with different time delays simultaneously. The time‐resolved spectra do not have any spectral distortion or artifacts, and the multi‐channel system improves the reliability of the data. As for the application, the reorientation process in a ferroelectric liquid crystal induced by the reversal of external electric field has been studied with a time resolution of 0.5
μ
s or less.
Optical Materials for Infrared Spectroscopy
Authors: Vidrine D. Warren
Published: September 2006

The sections in this article are

Introduction

Families of Transparent Materials

Composite Materials

Material Properties of Transmissive Optical Materials

Reflective Materials

Surface Figuring of Reflective Optics

Internet References
Fast Time‐Resolved Mid‐Infrared Spectroscopy Using Grating Spectrometers
Authors: Hashimoto Mamoru , Yuzawa Teturo , Kato Chihiro , Iwata Koichi , Hamaguchi Hiro‐o
Published: September 2006

The sections in this article are

Introduction

Instrumentation

Transient Infrared Absorption

AC
‐Coupling Detection

System Configuration

Infrared Light Source

Stimulation Source

Flowing Sample Cell

Infrared Monochromator

Detector and Pre‐Amplifier

Signal Processing

Commercial Time‐Resolved Infrared Spectrometer

Spectral Data Analysis with

SVD

Applications

Photoexcited States of

DMABN

Photoisomerization of All‐

trans

‐Retinal

Electric‐Field‐Induced Reorientation Dynamics of Liquid Crystals

Future Perspective
Tunable Filter and Discrete Filter Near‐Infrared Spectrometers
Authors: Wetzel David L. , Eilert Arnold J. , Sweat Joseph A.
Published: September 2006

The sections in this article are

Near‐Infrared Filter Spectrometers

Acousto‐Optic Tunable Filters

Introduction

Background and Theory

Features of an Acousto‐Optic Tunable Filter Spectrometer

A Typical Acousto‐Optic Tunable Filter Spectroscopy Scheme

Operation of an Acousto‐Optic

TFS

Performance of an Acousto‐Optic

TFS

Designed for Quantitative Analysis

Temporal Resolution with an Acousto‐Optic

TFS

Liquid Crystal Tunable Filters

Introduction

Nematic Liquid Crystal Tunable Filter Theory

Imaging with Liquid Crystal Tunable Filters

Discrete Multilayer Interference Filter Photometers
Infrared‐Emitting Diodes for Near‐Infrared Spectrometry
Authors: Rosenthal Todd C.
Published: September 2006

The sections in this article are

The Early Days of Near‐Infrared Spectrometry

NIR

Spectrometers Based on Infrared‐Emitting Diodes

Applications of
IRED
Spectrometers
R
aman Monochromators and Polychromators
Authors: Pelletier Michael J.
Published: September 2006

The sections in this article are

Introduction

Terminology

Article Layout

Critical Performance Needs

Efficient Use of Photons

Stray Light

Spectral Resolution

Calibration Stability

Data Acquisition Speed

Operational Flexibility

Cost

Key Components

Diffraction Gratings

Mirrors

Multielement Lenses

Focal Reducers

Laser Blocking Filters

Bandpass Filters

Slits

Properties Common to Both Dispersive Monochromators and Spectrographs

Optimal Slit Width

Dispersion

Focusing Tolerance

Polarization Effects

Monochromators

Nondispersive Monochromators

Dispersive Single‐Stage Monochromators

Dispersive Multiple‐Stage Monochromators

Polychromators

Multiple‐Filter Polychromators

One‐Dimensional Dispersive Spectrographs

Two‐Dimensional Spectrographs
Resonance
R
aman Spectroscopy
Authors: McHale Jeanne L.
Published: September 2006

The theory and practice of resonance Raman spectroscopy is discussed in this article. In this technique, laser radiation resonance with an allowed electronic transition is employed to excite the vibrational light scattering spectrum. The frequency shifts of the scattered light reveal vibrational transitions within the ground electronic state, while the intensity of each Raman band as a function of exciting frequency, called the Raman excitation profile, depends on the dynamics in the resonant excited electronic state. This chapter considers the experimental and theoretical aspects of determining absolute Raman intensities for the purpose of studying the dynamics of excited electronic states. Experimental considerations for the determination of absolute Raman cross sections include the polarization of incident and scattered light, and corrections for self‐absorption and instrument response. Theoretical approaches include the sum‐over‐state expression, transform theory, and time‐dependent theory. Applications of resonance Raman spectroscopy in the study of electron transfer and solvent dynamics are described.
Introduction to Nonlinear Raman Spectrometry
Authors: Zheltikov A.M.
Published: September 2006

The sections in this article are

Introduction

The Basic Principles

Excitation of
R
aman Vibrations

Wave Mixing in
R
aman‐Active Media

Nonlinear Polarization and Nonlinear Susceptibilities

Phase Matching

The Main Schemes of Nonlinear
R
aman Spectroscopy

Stimulated
R
aman Scattering

Coherent Anti‐Stokes
R
aman Scattering

Four‐Wave Mixing with a Hyper‐
R
aman Resonance

R
aman‐Induced Kerr Effect

Degenerate Four‐Wave Mixing

Polarization Technique

Polarization Properties of the Coherent Four‐Wave Mixing Signal

Suppressing the Nonresonant Background

Coherent Ellipsometry

Time‐Resolved Coherent Anti‐Stokes
R
aman Scattering

Conclusions and Outlook

Appendix 1

Glossary of Widely Used Nonlinear
R
aman Acronyms and Abbreviations
Coherent Anti‐Stokes
R
aman Spectroscopy
Authors: Ujj Laszlo , Atkinson George H.
Published: September 2006

Coherent anti‐Stokes Raman spectroscopy (CARS) has been shown to be one of the most powerful experimental methodologies for obtaining vibrational information from both stable and transient molecular species. The general theoretical and experimental principles associated with CARS, together with specific examples of its applications to important biological systems, are presented. A concise theoretical formalism of CARS, and its electronically resonant variant, is presented with an emphasis on points relevant to the interpretation of experimental spectra. Particular attention is given to deriving vibrational signatures from the Raman resonances observed in CARS data. The instrumental components required for obtaining typical CARS data are illustrated in a brief description of an experimental system used to record CARS spectra from biophysical molecules (photoactive protein reactions). Specific examples of CARS data are taken from measurements of stable and transient intermediates comprising the photoreactions of the bacteriorhodopsin (BR) and rhodopsin (Rh) proteins. Finally, an overview of developments to be anticipated in this field is presented.
Linear Dichroism in Infrared Spectroscopy
Authors: Buffeteau Thierry , Pézolet Michel
Published: September 2006

The absorption of linearly polarized infrared radiation by oriented samples is sensitive to the state of polarization of the incident radiation. This phenomenon is known as the infrared linear dichroism (IRLD). The degree of optical anisotropy in oriented samples can be characterized by measuring two spectra using light polarized parallel and perpendicular to a reference direction. In this chapter, the theoretical expressions allowing the quantitative determination of molecular orientation from IRLD measurements for systems showing both uniaxial and biaxial symmetry of orientation are described. In addition, typical examples of the use of IRLD to determine the orientation of polymers and biological membranes are presented. These results were obtained from either static measurements using normal or oblique incidence or dynamic measurements using a rotating polarizer or a photoelastic modulator (PM‐IRLD). The high sensitivity of PM‐IRLD allows following the kinetics of orientation over a short timescale.
Surface‐EnhancedRaman Scattering
Authors: Ewen Smith W. , Rodger Caroline
Published: September 2006

The sections in this article are

Introduction

Mechanisms of Surface Enhancement

Electromagnetic Enhancement

Charge Transfer Mechanism

SERS‐Active Substrates

Electrodes

Colloids

Silver Colloid

Applications

Surface EnhancedRaman Scattering

Surface Enhanced ResonanceRaman Spectroscopy

Advantages ofSERRS

Biology

Medicinal Chemistry

Surface Chemistry

Analysis

Polymers

Conclusions
Sum‐Frequency Spectroscopy
Authors: Beattie David A. , Bain Colin D.
Published: September 2006

Sum frequency spectroscopy (SFS) is one of the most versatile and powerful tools for obtaining surface vibrational spectra. SFS is a non‐linear optical technique that uses overlapping visible and infrared lasers to generate a signal from molecules aligned at an interface. The technique is both sensitive and selective; sub‐monolayer detection is routine and signal is only generated from molecules on the surface and not from the bulk media on either side of the interface. This article outlines the experimental and theoretical basis for the technique. In addition, a number of applications of SFS in surface and interface science are highlighted, including the study of interfacial water structure, surfactants at air–liquid interfaces, catalysis, and boundary lubrication.