bluuebunny/crossref_metadata_2025 huggingface dataset:
Non‐standard work schedules and retention in the entry‐level hourly workforce
Authors: Martin James E. , Sinclair Robert R. , Lelchook Ariel M. , Wittmer Jenell L. S. , Charles Kristin E.
Published: October 2010

Non‐standard work schedules involve work outside the Monday–Friday daytime hours. Although research has heavily studied the health and family effects of such schedules, few studies have investigated their relationship to retention. We draw from Maertz and Campion's discussion of motivational forces that influence turnover to propose that employees on non‐standard schedules are more likely to quit their employer because of general job dissatisfaction and because of normative pressures from family and/or friends. Specifically, we hypothesized that employees on day shifts or weekday only schedules would remain with their employer longer than those who work on nonday shifts or on the weekends. We also hypothesized that perceived employment mobility would moderate the effects of non‐standard schedules on retention length. Hypotheses were tested among 3,178 retail employees who worked five different distinct shift arrangements and different weekday/weekend schedules. Cox regression analyses indicated that, as hypothesized, employees working nonday shifts or schedules including weekends remained with their employer for a shorter duration of time than employees not on such schedules. Perceived mobility moderated the schedule–turnover relationship, though not in the hypothesized manner. We discuss the theoretical and practical implications of these findings for work schedule assignment and retention strategies.
Xylitol production from olive-pruning debris by sulphuric acid hydrolysis and fermentation with Candida tropicalis
Authors: García Martín Juan Francisco , Sánchez Sebastián , Bravo Vicente , Cuevas Manuel , Rigal Luc , Gaset Antoine
Published: October 2010

The debris of olive pruning is a renewable, low-cost and widely available agricultural waste. Its biochemical conversion by hydrolysis and fermentation was undertaken in the present study. Diluted acid hydrolysis was conducted in a heterogeneous stirred tank reactor at 90°C and at a low sulphuric acid concentration (0.0–1.0 N) for 300 min. To increase thed-xylose/d-glucose ratio into the hydrolysate, in another experiment amorphous cellulose and extracts were removed by means of a pretreatment in an extruder with 1 N H2SO4at 70°C before the acid hydrolysis. The fermentation of hydrolysates was performed under microaerobic conditions in a batch bioreactor at 30°C and pH 5 withCandida tropicalisNBRC 0618. The controlled fermentation parameters included maximum specific growth rate, biomass productivity, rate of the specific substrate uptake, rates of specific ethanol and xylitol production, and overall yield of ethanol and xylitol. In the presence of 1.0 N H2SO4, the fermentation of the pretreated hydrolysate led to specific xylitol production rates and overall xylitol yield (0.1 g g-1 h for t=25 h; 0.49 g g-1, respectively) higher than those achieved without pretreatment (0.03 g g-1 h for t=25 h; 0.39 g g-1, respectively). Under these conditions, 53 g xylitol kg-1of dry olive-pruning debris was obtained from the pretreated culture, whereas without pretreatment 70 g ethanol and 34 g xylitol were recovered.
Spherical PF resin beads prepared from phenol-liquefied Bambusa dolichoclada with suspension polymerization
Authors: Lee Wen-Jau , Yu Chao-Yun , Chang Kuo-Chun , Huang Ying-Pin , Chang Ching-Hui , Liu Cheng-Tzu
Published: October 2010

Bambusa dolichoclada Hayata (long-shoot bamboo) was liquefied in phenol with H2SO4 as a catalyst. The phenol-liquefied bamboo was then used as a raw material to prepare spherical phenol-formaldehyde (PF) resin beads by a suspension polymerization in a two-step process. The influence of the stirring speed (300, 350 and 400 rpm), the stabilizer dosage (3%, 4% and 5%) and the total molar ratio of formaldehyde to free phenol (F/P) (3.0/1, 3.5/1 and 4.0/1) on the properties of spherical PF beads was investigated. The results show that the yield, diameter and dimensional distribution of prepared PF beads were influenced by reaction conditions. The diameter of beads decreased as the stabilizer dosage increased. It had a more uniform dimensional distribution when stirred with a speed of 400 rpm. Differential scanning calorimetry analysis shows that PF beads obtained were not completely cured and the post-curing reaction took place at temperatures exceeded 150°C. As revealed by thermal gravimetric analysis, the char yield was over 60% after heating to 800°C.
Extraterrestrial Exegesis: The Raëlian Movement as a Biblical Religion
Authors: Gallagher Eugene V.
Published: October 2010

Interpretation of the Bible has played a central role in the origins and development of the Raëlian movement. Claude Vorilhon's first encounter with the "Elohim" was immediately followed by an intensive week of Bible study that gave him a new identity as the messianic prophet "Raël," a new direction for his life as the earthly ambassador of the Elohim, and a new doctrine that would serve as the intellectual foundation of a new religious movement. The Raëlian movement and other new religions in which interpretation of the Bible figure prominently do not originate one-sidedly in a "cultic milieu" or "occulture" that is divorced from the broad biblical tradition. Rather, they represent creative blendings of biblical and other sources. Part of the attractiveness of the Bible for new religions is that it contains and legitimizes multiple examples of successful religious innovation.
Bible Lessons with Raël: On Religious Appropriation in ET-Inspired Religions
Authors: Thomas Paul Brian
Published: October 2010

As an introduction to Nova Religio's special issue on ET-inspired (UFO) religions, this article maintains that despite less media attention since the furor surrounding the Heaven's Gate suicides, ET-inspired religions are still active. Moreover, increasing speculation linking extraterrestrials to 2012 apocalyptic scenarios, coupled with a significant percentage of the population who believe in extraterrestrial visitation, seems to indicate that purveyors of ET-inspired religious perspectives will continue to have a market. Rather than focusing upon the "strange" and seemingly "bizarre" nature of these religious groups, the articles in this special issue endeavor to demonstrate how members of ET-inspired religions appropriate materials and theological ideas from widely-accepted mainstream religious traditions. This article maintains that the value of such an approach lies in bridging the gulf between normalized religious perspectives and the marginalized religious "other."
Revisionism in ET-Inspired Religions
Authors: Thomas Paul Brian
Published: October 2010

By utilizing the textual products of extraterrestrial-inspired religious thinkers like George Van Tassel, Raël, and Patricia Cori, as well as related materials by Erich von Däniken and Zecharia Sitchin, this article explores the concept of revisionism in ET-inspired religions. The authors examined in this article reread ancient religious texts, especially the Bible, as containing evidence of extraterrestrial influence in the course of human history. The anatomy of this "drive to revise" human history is explored, including an examination of how an improvisational millenarianism combines with a cultic milieu suspicious of authority and hegemonic narratives, and the conspiratorial intellectual maverick willing to work with "stigmatized" knowledge to produce narratives that are highly critical and suspicious of established intellectual authorities and procedures.
"These Are They": ET-Human Hybridization and the New Daemonology
Authors: Flaherty Robert Pearson
Published: October 2010

This article examines how the myth of extraterrestrial (ET)-human hybridization reworks earlier traditions of superhumanhuman hybridity, how the ETs of current lore represent the morphological projection of the direction of human evolution, and how the myth of ET-human hybridization tracks current developments in reproductive technology and increased understanding of reproductive processes. The myth of ET-human hybridization mediates the tension between individualism and collectivism (one of the most basic concepts of cultural psychology). Whereas the ETs of 1950s-style ET-contactee myth promised salvation from nuclear war, the ETs of the current hybridization myth need us as much as we need them.
Variability in Chinese: The Case of a Morphosyntactic Particle
Authors: Li Xiaoshi
Published: October 2010

DE (?) is the most widely used morphosyntactic particle in Chinese and its most salient features are multifunctionality and optionality. Most existing research is prescriptive and very few studies investigate how speakers actually use DE. This study describes Chinese speakers’ DE use and the effects of linguistic functions, gender, and formality. Results show that contrary to prescriptive claims, speakers occasionally omit DE from clause as modifier environments. Multivariate analysis of DE tokens shows both DE functions and gender are significant. Females tend to use DE more than males. Finally, comparison results of DE use in formal vs. informal situations and oral vs. writing indicate that DE tends to be omitted more in informal speech than in formal situations and writings.
Las prácticas y estilos de literacidad de los adolescentes fuera de la escuela: una exploración cuantitativa de las relaciones entre literacidad, escolarización y origen familiar
Authors: Poveda David
Published: October 2010

Este artículo presenta el análisis de un cuestionario sobre formas de lectura y escritura extra-escolares aplicado a una muestra de 2.283 alumnos de Educación Secundaria Obligatoria de la ciudad de Madrid (España). El cuestionario explora tres ámbitos de la vida de los adolescentes, (a) sus prácticas de lectura y escritura, así como las de otros adultos de su familia, (b) sus características socio-demográficas y (c) sus expectativas y trayectorias académicas. Un análisis factorial sobre los ítems de lectura-escritura arroja ocho factores, identificables como diferentes prácticas de literacidad. Un análisis de conglomerados hecho sobre los factores produce tres agrupamientos, identificados como estilos de literacidad. Los resultados apoyan de manera cuantitativa una visión multidimensional de la literacidad en los adolescentes, congruente con los planteamientos de los Nuevos Estudios sobre la Literacidad. Igualmente, los datos no han permitido establecer una asociación clara entre estilo de literacidad y resultados académicos.
Mortalidade por doenças cardiorrespiratórias em idosos no estado de Mato Grosso, 1986 a 2006
Authors: Carmo Cleber Nascimento do , Hacon Sandra de Souza , Jacobson Ludmilla da Silva Viana , Mourão Dennys de Souza , Ignotti Eliane
Published: October 2010

OBJETIVO: Descrever a evolução temporal da mortalidade por doenças cardiorrespiratórias em idosos. MÉTODOS: Estudo epidemiológico descritivo com delineamento ecológico de séries temporais realizado no estado do Mato Grosso, de 1986 a 2006. Foram utilizados dados sobre doenças dos aparelhos respiratório e circulatório obtidos do Sistema de Informação sobre Mortalidade do Ministério da Saúde. Modelos de regressão linear simples foram ajustados para avaliar a tendência das taxas específicas de mortalidade por grupos específicos de idade (60 a 69, 70 a 79 e 80 ou mais anos) e sexo. RESULTADOS: Houve aumento na proporção de óbitos por doenças respiratórias e diminuição por doenças cardiovasculares. Na comparação de taxas entre os sexos, as mulheres apresentaram taxas 15% menores para as causas cardiovasculares e taxas similares ao sexo masculino para as causas respiratórias. Foi observada taxa elevada de mortalidade por doenças respiratórias e cardiovasculares, com importante tendência de incremento entre os grupos mais longevos. Em idosos com idade > 80 anos o aumento anual médio na taxa de mortalidade por doenças respiratórias foi de 1,99 óbitos e de 3,43 por doenças do aparelho circulatório. CONCLUSÕES: O estado de Mato Grosso apresenta elevada taxa de mortalidade por doenças respiratórias e cardiovasculares em idosos, com importante tendência de incremento entre os grupos mais longevos.
Symphysis-fundal height curve in the diagnosis of fetal growth deviations
Authors: Freire Djacyr Magna Cabral , Cecatti Jose Guilherme , Paiva Cláudio Sergio Medeiros
Published: October 2010

OBJECTIVE: To validate a new symphysis-fundal curve for screening fetal growth deviations and to compare its performance with the standard curve adopted by the Brazilian Ministry of Health. METHODS: Observational study including a total of 753 low-risk pregnant women with gestational age above 27 weeks between March to October 2006 in the city of João Pessoa, Northeastern Brazil. Symphisys-fundal was measured using a standard technique recommended by the Brazilian Ministry of Health. Estimated fetal weight assessed through ultrasound using the Brazilian fetal weight chart for gestational age was the gold standard. A subsample of 122 women with neonatal weight measurements was taken up to seven days after estimated fetal weight measurements and symphisys-fundal classification was compared with Lubchenco growth reference curve as gold standard. Sensitivity, specificity, positive and negative predictive values were calculated. The McNemar χ2 test was used for comparing sensitivity of both symphisys-fundal curves studied. RESULTS: The sensitivity of the new curve for detecting small for gestational age fetuses was 51.6% while that of the Brazilian Ministry of Health reference curve was significantly lower (12.5%). In the subsample using neonatal weight as gold standard, the sensitivity of the new reference curve was 85.7% while that of the Brazilian Ministry of Health was 42.9% for detecting small for gestational age. CONCLUSIONS: The diagnostic performance of the new curve for detecting small for gestational age fetuses was significantly higher than that of the Brazilian Ministry of Health reference curve.
Housing conditions as a social determinant of low birthweight and preterm low birthweight
Authors: Vettore Mario Vianna , Gama Silvana Granado Nogueira da , Lamarca Gabriela de Almeida , Schilithz Arthur Orlando Corrêa , Leal Maria do Carmo
Published: October 2010

OBJECTIVE: To assess the relationship between housing conditions and low birthweight and preterm low birthweight among low-income women. METHODS: A case-control study was conducted with post-partum women living in the city of Rio de Janeiro, Southeast Brazil, in 2003-2005. Two groups of cases, low birthweight (n=96) and preterm low birthweight infants (n=68), were compared against normal weight term controls (n=393). Housing conditions were categorized into three levels: adequate, inadequate, and highly inadequate. Covariates included sociodemographic and anthropometric characteristics, risk behaviors, violence, anxiety, satisfaction during pregnancy, obstetric history and prenatal care. RESULTS: Poor housing conditions was independently associated with low birthweight (inadequate - OR 2.3 [1.1;4.6]; highly inadequate - OR 7.6 [2.1;27.6]) and preterm low birthweight (inadequate - OR 2.2 [1.1;4.3]; highly inadequate - OR 7.6 [2.4;23.9]) and factors associated with outcomes were inadequate prenatal care and previous preterm birth. Low income and low maternal body mass index remained associated with low birthweight. CONCLUSIONS: Poor housing conditions were associated with low birthweight and preterm low birthweight.
Yellow fever in Brazil: thoughts and hypotheses on the emergence in previously free areas
Authors: Vasconcelos Pedro Fernando da Costa
Published: October 2010

This article describes and discusses factors associated to the reemergence of yellow fever and its transmission dynamics in the states of São Paulo (Southeastern Brazil) and Rio Grande do Sul (Southern) during 2008 and 2009. The following factors have played a pivotal role for the reemergence of yellow fever in these areas: large susceptible human population; high prevalence of vectors and primary hosts (non-human primates); favorable climate conditions, especially increased rainfall; emergence of a new genetic lineage; and circulation of people and/or monkeys infected by virus. There is a need for an effective surveillance program to prevent the reemergence of yellow fever in other Brazilian states.
The 11-year follow-up of the 1993 Pelotas (Brazil) birth cohort study: methods
Authors: Araújo Cora Luiza , Menezes Ana M. B. , Vieira Maria de Fátima A. , Neutzling Marilda B. , Gonçalves Helen , Anselmi Luciana , Dumith Samuel C. , Hallal Pedro C.
Published: October 2010

The aim of this study is to describe the methodology of the 2004-2005 follow-up visit of the 1993 Pelotas (Brazil) birth cohort. All children born in Pelotas in 1993 and whose mothers lived in the city at that time were eligible to be enrolled in a longitudinal study. Between July 2004 and March 2005, all cohort participants were sought for a follow-up visit. Several strategies were used to help trace cohort members, including a census of the city's schools and a census of all households in the municipality. The Mortality Information System was monitored in order to identify deaths among cohort members. Of the 5,249 cohort members, 4,452 were interviewed in 2004-5. When added to the 141 deaths, these represent 87.5% of the original cohort. In spite of the logistic and financial difficulties, it is possible to carry out prospective studies with long-term follow-up in the Brazilian context.
Well-being in adolescents: the 11-year follow-up of the 1993 Pelotas (Brazil) birth cohort study
Authors: Hallal Pedro C. , Dumith Samuel C. , Bertoldi Andréa D. , Scalco Diogo L. , Menezes Ana M. B. , Araújo Cora Luiza
Published: October 2010

Studies on well-being and its possible determinants are rare in the international literature, and almost non-existent in Brazil, particularly among youth. The present study focused on the epidemiology of well-being among adolescents belonging to a birth cohort. Well-being was measured using face-to-face interviews, with a question whose answer was based on a graphic scale of faces. 4,452 adolescents were interviewed. Approximately half (49.4%) classified themselves as very happy (face 1); this proportion was higher among girls than boys. Poorer adolescents were more likely than their wealthier peers to identify with the happiest face (number 1), but were also more likely to report moderate to low levels of well-being (faces 3-7). Body mass index was inversely associated with well-being. Among girls, physical activity was directly associated with well-being.
Factors associated with weight loss dieting among adolescents: the 11-year follow-up of the 1993 Pelotas (Brazil) birth cohort study
Authors: Madruga Samanta W. , Azevedo Mario Renato de , Araújo Cora Luiza , Menezes Ana M. B. , Hallal Pedro C.
Published: October 2010

Evidence has shown the negative effects of unsupervised diets and those with excessive calorie restriction. The aim of this study was to determine the proportion of adolescents engaging in weight loss dieting and associated factors. This was a cross-sectional study of 4,452 adolescents born in Pelotas, Rio Grande do Sul State, Brazil, in 1993. The outcome was defined as adolescents that reported having practiced some type of weight loss dieting in the previous 12 months. Prevalence of such dieting was 8.6% (95%CI: 7.7;9.4), and was higher in girls. Elevated maternal body mass index (BMI) was associated with dieting among girls. The adolescent's and parents' view of the adolescent's weight, excess weight, and consumption of diet or light soft drinks were associated with adolescent dieting. There was a positive association between dieting and socioeconomic status. The findings provide important backing for policies aimed at improving adolescents' diet, since they express a major concern over weight and thus a significant percentage of individuals with erroneous and unhealthy behaviors.
Experimental use of alcohol in early adolescence: the 11-year follow-up of the 1993 Pelotas (Brazil) birth cohort study
Authors: Noal Ricardo B. , Menezes Ana M. B. , Araújo Cora Luiza , Hallal Pedro C.
Published: October 2010

The aim of this study was to estimate the prevalence of experimental alcohol intake and associated factors in early adolescence. The overall sample consisted of 4,452 adolescents (mean age = 11.3 years; SD = 0.3) from the 1993 birth cohort in Pelotas, Rio Grande do Sul State, Brazil. Experimental use of alcohol was reported by 17.5% of the interviewees (95%CI: 16.3-18.6), and 5% reported having tried alcohol at nine years of age or younger. Prevalence of experimental alcohol use was higher among adolescents whose mothers had consumed alcohol during pregnancy, whose parents consumed alcohol, who worked outside the home themselves, and who had ever tried smoking. Family strife, parental alcohol intake, and adolescent smoking were strong predictors of experimental alcohol use in early adolescence. Special attention should be targeted to these groups in order to avoid heavy and premature alcohol use in early adolescence.
Resting pulse rate among adolescents: the 11-year follow-up of the 1993 Pelotas (Brazil) birth cohort study
Authors: Hallal Pedro C. , Menezes Ana M. B. , Bertoldi Andréa D. , Dumith Samuel C. , Araújo Cora Luiza
Published: October 2010

The aim of this study was to describe resting pulse rate and associated factors among adolescents. This was a cross-sectional analysis nested in a prospective cohort study, including 4,452 adolescents born in Pelotas, Rio Grande do Sul State, Brazil in 1993, representing 87.5% of the original cohort. Pulse rate was measured with an electronic device at the beginning and end of the interview, and the mean value was used in the analyses. Mean pulse rate was 78.4bpm (SD = 11.0) in the total sample, 76.5bpm (SD = 10.7) in boys, and 80.2bpm (SD = 10.9; p < 0.001) in girls. Black adolescents showed lower mean pulse rates. There was a direct association between pulse rate and blood pressure. Physical activity was inversely associated with pulse rate in the crude analysis only. Elevated pulse rate is strongly associated with high blood pressure, and both variables are predictors of risk of chronic disease in adulthood.
Concurrent determinants of blood pressure among adolescents: the 11-year follow-up of the 1993 Pelotas (Brazil) birth cohort study
Authors: Menezes Ana M. B. , Hallal Pedro C. , Araújo Cora Luiza , Barros Fernando C. , Victora Cesar G.
Published: October 2010

The aim of this study was to evaluate concurrent risk factors for high blood pressure in adolescents. This is a prospective cohort study including 4,452 adolescents born in Pelotas, Rio Grande do Sul State, Brazil, in 1993. Blood pressure was measured before and after the interview, and the mean value was used in the analyses. Mean systolic blood pressure was 101.9mmHg (SD = 12.3) and mean diastolic pressure was 63.4mmHg (SD = 9.9). Adolescents with black skin had higher blood pressure than those with white skin. Mean systolic pressure among subjects in the top quartile of body mass index (BMI) was 11.6mmHg higher than among those in the lowest quartile. Mean systolic pressure among postmenarcheal girls was 5.4mmHg higher than among premenarcheal girls. Similar trends were found for diastolic arterial pressure. Our findings suggest that blood pressure control must begin already in childhood and adolescence.
Hospital admissions from birth to early adolescence and early-life risk factors: the 11-year follow-up of the 1993 Pelotas (Brazil) birth cohort study
Authors: Menezes Ana M. B. , Noal Ricardo B. , Cesar Juraci A. , Hallal Pedro C. , Araújo Cora Luiza , Dumith Samuel C. , Barros Fernando C. , Victora Cesar G.
Published: October 2010

The aim of this prospective analysis was to describe the cumulative incidence of hospital admissions in the first year of life and between 1 and 11 years of age and to explore associated factors. Hospital admissions were collected through regular monitoring in the first year of life, and through maternal report on admissions between 1 and 11 years. Analyses were stratified by sex and adjusted for confounding factors. 18.1% of children were hospitalized in the first year of life, and 30.7% between ages 1 and 11 years. Among boys, hospital admission in the first year was associated with low family income, paternal smoking during pregnancy, preterm delivery, and low birthweight. Among girls, in addition to the variables described for boys, black/mixed skin color was also a risk factor for hospital admission. For admissions between 1 and 11 years of age, low family income and gestational age > 37 weeks were found to be significant risk factors.
Comparison of grey water treatment performance by a cascading sand filter and a constructed wetland
Authors: Kadewa W. W. , Le Corre K. , Pidou M. , Jeffrey P. J. , Jefferson B.
Published: October 2010

A novel unplanted vertical flow subsurface constructed wetland technology comprising three shallow beds (0.6 m length, 0.45 m width and 0.2 m depth) arranged in a cascading series and a standard single-pass Vertical Flow Planted Constructed Wetland (VFPCW, 6 m2 and 0.7 m depth) were tested for grey water treatment. Particular focus was on meeting consent for published wastewater reuse parameters and removal of anionic surfactants. Treatment performance at two hydraulic loading rates (HLR) of 0.08, and 0.17 m3 m−2 d−1 were compared. Both technologies effectively removed more than 90% turbidity and more than 96% for organics with the prototype meeting the most stringent reuse standard of <2 NTU and <10 mg/L. However, surfactant removal in the VFPCW was higher (76–85%) than in the prototype which only achieved more than 50% removal at higher loading rate. Generally, the prototype performed consistently better than the VFPCW except for surfactant removal. However, at higher loading rates, both systems did not meet the reuse standard of <1 mg L−1 for anionic surfactants. This observation confirms that shallow beds provide a more oxidised environment leading to higher BOD5 and COD removals. Presence of plants in the VFPCW led to higher anionic surfactant removal, through increased microbial and sorption processes.
Partial nitrification of non-ammonium-rich wastewater within biofilm filters under ambient temperature
Authors: Wang Hongyu , He Jiajie , Yang Kai
Published: October 2010

This study evaluated the partial nitrification performances of two biofilm filters over a synthetic non-ammonium-rich wastewater at a 20°C room temperature under both limited DO (∼2.0 mg/L) and unlimited DO (∼4.0 mg/L) conditions. The two filters were each of 80 cm long and used different biofilm carriers: activated carbon and ceramic granule. Results showed that partial nitrification was accomplished for both filters under the limited DO condition. However, the effluent NO2-N was higher in the ceramic granule filter than in the activated carbon filter, and was less susceptible to the influent COD/N changes. Further investigation into the water phase COD and NH4-N depth profiles and bacteria population within the two filters showed that by putting upper filter layer (upstream) to confront relatively higher influent COD/N ratios, the filtration process naturally put lower filter layers (downstream) relatively more favorable for nitrifying bacteria (ammonia oxidizing bacteria in this study) to prosper, making the filter depth left for nitrification a crucial factor for the effectiveness of nitrification with a filter. The potentially different porous flow velocities of the two filters might be the reason to cause their different partial nitrification performances, with a lower porous flow velocity (the ceramic granule filter) favoring partial nitrification more. In summation, DO, filter depth, and filtration speed should be played together to successfully operate a biofilm filter for partial nitrification.
Operating boundaries of full-scale advanced water reuse treatment plants: many lessons learned from pilot plant experience
Authors: Bele C. , Kumar Y. , Walker T. , Poussade Y. , Zavlanos V.
Published: October 2010

Three Advanced Water Treatment Plants (AWTP) have recently been built in South East Queensland as part of the Western Corridor Recycled Water Project (WCRWP) producing Purified Recycled Water from secondary treated waste water for the purpose of indirect potable reuse. At Luggage Point, a demonstration plant was primarily operated by the design team for design verification. The investigation program was then extended so that the operating team could investigate possible process optimisation, and operation flexibility. Extending the demonstration plant investigation program enabled monitoring of the long term performance of the microfiltration and reverse osmosis membranes, which did not appear to foul even after more than a year of operation. The investigation primarily identified several ways to optimise the process. It highlighted areas of risk for treated water quality, such as total nitrogen. Ample and rapid swings of salinity from 850 to 3,000 mg/l-TDS were predicted to affect the RO process day-to-day operation and monitoring. Most of the setpoints used for monitoring under HACCP were determined during the pilot plant trials.
Effect of chloride concentration on nitrogen removal from landfill leachate in sequencing batch reactor after MAP pretreatment
Authors: Chen M. , He S. , Yi Q. , Yang M.
Published: October 2010

Leachate generated from landfill is becoming a great environmental challenge to China as it contains high concentration of COD, ammonium and some other substances. Nitrogen removal through the conventional nitrification-denitrification process is hampered by the low C/N ratio especially for the old age landfill sites and the high energy consumption for aeration. In this study, the combination of magnesium ammonium phosphate (MAP) precipitation and Sequencing batch reactor (SBR) was suggested as a new process for the treatment of high strength ammonium, and the effect of high concentration of Cl− after MAP precipitation because of the use of MgCl2 was investigated on SBR performance. The practical upper limit of Cl− for nitrification was found to be 12,000 mg/L, above which resulted in significant accumulation of ammonium in SBR system. It is suggested that an ammonium removal of 70% was suitable for the MAP treatment to achieve a balance between increasing the C/N ratio and avoiding detrimental effect from high concentration of Cl− in the succeeding SBR system. DGGE analysis indicated that high diversity of Ammonium oxidizing bacteria (AOB) could be maintained at a Cl− concentration of 12,000 mg/L.
Effect of digester F/M ratio on gas production and sludge minimization of ultrasonically treated sludge
Authors: Köksoy Gözde T. , Sanin F. Dilek
Published: October 2010

Sludge pretreatment by mechanical, chemical or thermal methods before anaerobic digestion has been applied to increase the digestability of excess sludge. Pretreatment processes rely on their ability to disrupt cell membranes and to release organic materials from the cells into the aqueous phase. Pretreatment by mechanical disintegration has grown rapidly in recent years in parallel with the advances in technology. Ultrasonic sludge disintegration –one of the most commonly used mechanical pretreatment methods- enables the occurrence of cavitation bubbles for the break-up of microorganism cells to extract intracellular materials. The purpose of this study was to conduct disintegration experiments to optimize sonication parameters and to operate subsequent batch anaerobic digesters to examine the effect of food to microorganism ratio (F/M) in sonicated and unsonicated samples. Results showed that high sonication powers and longer treatment times were effective in sludge disintegration in terms of soluble chemical oxygen demand release. Sonicated sludge digested in batch reactors with higher initial F/M ratio caused higher methane generations, higher sludge reductions and had better dewatering characteristics.
Analysis of variation and relation of climate, hydrology and water quality in the lower Mekong River
Authors: Hanh Pham Thi Minh , Anh Nguyen Viet , Ba Dang The , Sthiannopkao Suthipong , Kim Kyoung-Woong
Published: October 2010

In order to determine the influence of climate and hydrology on water quality of the lower Mekong River, the long term monitoring data (from 1985 to 2004) of climatic, hydrological and water quality variables were analyzed. In general, water quality was ‘good’ or ‘very good’ for most of the investigated water quality parameters including DO, pH, conductivity, nitrate, phosphate and total phosphorus. All climatic and hydrological elements as well as most of the water quality parameters varied seasonally. Throughout the 18-year period, only evaporation, water level and TSS showed a significant pertinent trend. ARIMA models results reveal that among climatic and hydrological paremeters, water quality could be effectively predicted from the data of discharge flow and precipitation. The results showed good R2 (≥0.7) estimation between predicted and observed values for TSS, alkalinity and conductivity which are the chemically and biologically conservative parameters. For other water quality parameters such as Ca2 + , Mg2 + , Si, Cl−, NO3−, and SO42−, the predicting results by ARIMA model were reliable in shorter period than the above three mentioned variables.
On site flotation for recovering polluted aquatic systems: is it a feasible solution for a Brazilian urban river?
Authors: Cunha D. G. F. , Grull D. , Damato M. , Blum J. R. C. , Lutti J. E. I. , Eiger S. , Mancuso P. C. S.
Published: October 2010

Pinheiros River (Brazil) plays a pivotal role in supplying water to Billings Reservoir, which presents multiple uses (human drinking, energy generation, irrigation, navigation, fishing and leisure). An intense monitoring program was performed during the years 2007 and 2008 to find out whether on site flotation is a feasible solution or not for improving the water quality of this urban river, attenuating the pollutants load caused by the water pumping to the reservoir (approximately 10 m3 s−1). The monitoring of 18 variables (13,429 laboratorial analysis during the period of 490 days), suggested that despite the convenience of the on site approach for water treatment, especially for rivers located in fully urbanized areas, the flotation system is not enough itself to recover Pinheiros River water quality, given the several constraints that apply. Total phosphorus removal was high in percentage terms (about 90%), although the remaining concentrations were not so low (mean of 0.05 mg L−1). The removal efficiency of some variables was insufficient, leading to high final mean concentrations of metals [e.g. aluminium (0.29 mg L−1), chromium (0.02 mg L−1) and iron (1.1 mg L−1)] as well as nitrogen-ammonia (25.8 mg L−1) and total suspended solids (18 mg L−1) in the treated water.
Plasma degradation of Cationic Blue dye with contact glow discharge electrolysis
Authors: Xing-long Jin , Xiao-yan Wang , Qing-feng Wang , Jun-jie Yue , Ya-qi Cai
Published: October 2010

Contact glow discharge electrolysis (CGDE) of Cationic Blue SD-GTL (CB) was investigated by determining degradation rates and rate constants under different voltages, pH, temperature and initial concentrations. The results indicated that 500 V was the optimum voltage for CGDE of CB under experimental conditions. The effect of pH was not appreciable. Fe2 +  and Fe3 +  had a remarkable catalytic effect on the degradation of CB. The degradation rate was up to 99.7% after 3 minutes CGDE treatment when the concentration of Fe2 +  was 20.0 mg/L. And when the concentration of Fe3 +  was 5.0 mg/L, the degradation rate was only 68.6% after 10 minutes CGDE treatment. The reaction mechanisms were also well illustrated by relative reactions and their rate constants. It had been demonstrated that CB underwent oxidative degradation in CGDE.
A water sustainability index for West Java – Part 2: refining the conceptual framework using Delphi technique
Authors: Juwana I. , Perera B. J. C. , Muttil N.
Published: October 2010

In the first paper of this two-part series on the development of a water sustainability index for West Java, a conceptual framework of West Java Water Sustainability Index (WJWSI) was developed. It consists of three main parts: components, indicators/sub-indicators and threshold values. This second paper of the series presents the application of the Delphi technique, followed by in-depth interviews with selected key experts, to refine the conceptual WJWSI framework. The Delphi application includes the design of the questionnaires, the selection of respondents, the distribution and collection of the completed questionnaires and the analysis of data. After Round One of the Delphi application, the respondents reached consensus for all proposed components in the conceptual framework. However, some modifications to the components were also suggested by few respondents. Regarding the indicators/sub-indicators, consensus for 9 of the proposed 12 indicators was reached, and 5 new indicators were suggested. For the threshold values, consensus was reached for threshold values of 5 indicators. In Round Two of the Delphi application, respondents were asked questions related to results from Round One, which include the modification on the components, indicators/sub-indicators which have not been agreed, and newly suggested indicators/sub-indicators and threshold values. Results of Round Two show that modifications on the components were agreed, and consensus was reached for 8 out of the proposed 9 indicators/sub-indicators. In terms of its components and indicators, the framework was then finalised in the in-depth interview with four key experts, selected from different respondent categories. For the threshold values not yet finalised, further study will be carried out, as there was not much input from the respondents in the Delphi application and the in-depth interview.
Study on cement mortar and concrete made with sewage sludge ash
Authors: Chang F. C. , Lin J. D. , Tsai C. C. , Wang K. S.
Published: October 2010

This study investigated the feasibility of reusing wastewater sludge ash in construction materials to replace partial materials. Wastewater sludge sampled from thermal power plant was burned into sludge ash at 800°C in the laboratory. The sludge incineration ash has low heavy metal including Pb, Cd, Cr and Cu, so it belongs to general enterprise waste. The chemical composition of sludge incineration ash was summed up in SiO2, CaO, Fe2O3 and MgO. Then the wastewater sludge ash is also found to be a porous material with irregular surface. When the sludge ash was used to replace mortar or concrete cement, its water-adsorption capability will result in the reduction of mortar workability and compressive strength. Cement is being substituted for sludge ash, and 10 percent of sludge ash is more appropriate. Sludge ash is reused to take the place of construction materials and satisfies the requests of standard specification except for higher water absorption.
Combining multimedia models with integrated urban water system models for micropollutants
Authors: De Keyser W. , Gevaert V. , Verdonck F. , Nopens I. , De Baets B. , Vanrolleghem P. A. , Mikkelsen P. S. , Benedetti L.
Published: October 2010

Integrated urban water system (IUWS) modeling aims at assessing the quality of the surface water receiving the urban emissions through sewage treatment plants, combined sewer overflows (CSOs) and stormwater drainage systems. However, some micropollutants tend to appear in more than one environmental medium (air, water, sediment, soil, groundwater, etc.). In this work, a multimedia fate and transport model (MFTM) is “wrapped around” a dynamic IUWS model for organic micropollutants to enable integrated environmental assessment. The combined model was tested on a hypothetical catchment using two scenarios: on the one hand a reference scenario with a combined sewerage system and on the other hand a stormwater infiltration pond scenario, as an example of a sustainable urban drainage system (SUDS). A case for Bis(2-ethylhexyl) phthalate (DEHP) was simulated and resulted in reduced surface water concentrations for the latter scenario. However, the model also showed that this was at the expense of increased fluxes to air, groundwater and infiltration pond soil. The latter effects are generally not included in IUWS models, whereas MTFMs usually do not consider dynamic surface water concentrations,; hence the combined model approach provides a better basis for integrated environmental assessment of micropollutants' fate in urban environments.
Reducing the effect of cyanobacteria in the microfiltration of secondary effluent
Authors: Goh Y. T. , Harris J. L. , Roddick F. A.
Published: October 2010

Cyanobacterial blooms in the lagoons of sewage treatment plants can severely impact the performance of membrane plants treating the effluent. This paper investigates the impact of Microcystis aeruginosa in a secondary effluent on the microfiltration filterability and cleaning of the membrane. Alum coagulation and dissolved air flotation (DAF) were investigated to remove the algae and so enhance the volume of effluent processed, and their influence on reversible and irreversible fouling. Degree of fouling due to the algal components was found to be in decreasing order of algal cells, algal organic matter and extracellular organic matter. Alum coagulation with 5 mg L−1 as Al3 +  led to a substantial increase in permeate volume, an increase in dissolved organic carbon removal, and a foulant layer which protected the membrane from internal fouling but which was hydraulically removable resulting in full flux recovery. Pre-treatment by DAF or 1.5 μm filtration following alum coagulation enhanced the flux rate and permeate volume but exposed the membrane to internal irreversible fouling.
Model assisted startup of anaerobic digesters fed with thermally hydrolysed activated sludge
Authors: Batstone D. J. , Balthes C. , Barr K.
Published: October 2010

This paper presents the use of the IWA ADM1 to predict and interpret results from two full-scale anaerobic digesters fed with thermal hyrolysate (waste activated sludge with a long upstream sludge age) from a Cambi hydrolysis process operating at 165°C and 6 bar-g. The first digester was fed conventionally—though intermittently, while the second was heavily diluted through a substantial component of the evaluation period (110 days). There were a number of important outcomes—related to both model application, and model predictions. Input and inert COD: mass ratio was very important, and was considerably higher than the 1.42 g g−1 used for biomass throughout the IWA activated sludge and anaerobic digestion models. Input COD: VS ratio was 1.6 g g−1, and inert COD: VS ratio was 1.7 g g−1. The model succeeded on a number of levels, including effective prediction of important outputs (degradability, gas flow and composition, and final solids), clarification of the substantial data scatter, prediction of recovery times during operationally poor periods, and cross-validation of the results between digester 1 and digester 2. Key failures in model performance were related to an early incorrect assumption of the COD: VS ratio of 1.42 g g−1, and intermittent high acetate levels, most likely caused by inhibition, and rapid acclimatisation to ammonia. The acute free ammonia limit was found to be 0.008 M NH3–N, while the chronic inhibition constant (KI,NH3,ac) was 0.007 ± 0.001 M NH3–N. Overall, this is a complex system, and application of the model added significant confidence to the initial operational decisions during an aggressive startup on an atypical feed.
Effect of ozonation on activated sludge from pulp and paper industry
Authors: Gupta S. , Chakrabarti S. K. , Singh S.
Published: October 2010

Aerobic biological treatment with activated sludge is the predominant process all over the world for treatment of pulp and paper industry wastewater. 50–70% of the biodegradable organic material is oxidized to CO2 and the rest is converted to bacterial biomass, typically termed as excess sludge or waste activated sludge (WAS). Handling and disposal of WAS in general and in particular from the pulp and paper industry face different processing difficulties, regulatory stringency due to organochlorine contamination and reluctance of people for reuse. With an objective of reducing the net disposable biomass, ozonation of WAS from a pulp and paper mill and from a laboratory scale batch activated sludge process operated with the wastewater and bacterial seed of the same pulp and paper mill have been carried out. With the mill sludge having predominant filamentous organisms 18% MLSS was reduced at an ozone dosage of 55 mg O3/g dry MLSS solid (DS) resulting in 2.5 times COD increase. With the laboratory sludge which is well structured and flocculating, only 6% MLSS was reduced at an ozone dosage of 55 mg O3/g DS. Ozonation mineralizes 26% and 20% AOX compounds embedded in the secondary sludge in the mill and laboratory sludge respectively at an ozone dosage of 55 mg O3/g DS. During ozonation, absorbed/adsorbed lignin on biomass was released which resulted in increased colour concentration. Ozonation can be a potential oxidative pretreatment process for reducing the WAS and paving the way for cost effective overall treatment of WAS.
Electro-coagulation treatment efficiency of graphite, iron and aluminum electrodes using alum and wood ash electrolytes on a Kraft pulp and paper mill effluent
Authors: Orori O. B. , Etiégni L. , Senelwa K. , Mwamburi M. M. , Balozi K. B. , Barisa G. K. , Omutange E. S.
Published: October 2010

Specific power consumption and reduction of BOD, COD, TS, pH, and chemical elements were used to determine the treatment efficiency of Fe, graphite and Al electrodes with alum and wood ash as supporting electrolytes on the effluent from a Kraft pulp and paper mill in Kenya. Five sampling points were selected along mill's effluent treatment system: primary settling tank (SP1), first aerated lagoon (SP2), second aerated lagoon (SP3), stabilization pond (SP4), and at discharge point (SP5). Operating costs were also compared between treatments. Graphite electrodes combined with alum showed the lowest power consumption (0.5 to 3.9 mWh/m3), followed by Al and Fe. All the electrodes reduced color from a maximum of 3,200°H to the minimum local standard of 15°H. However Al electrode with alum was the most effective method for BOD and COD reduction by over 60% and 58.8% respectively and generated less sludge at all sampling points. The cost of treatment was lowest with graphite electrode (US$0.006 to 0.0008 per m3 of effluent), but highest with Al electrodes combined with wood ash (US$31.74 to 8.34 per m3). Further study is required for the effectiveness of increasing the concentration of wood ash leachate at higher concentration and current density.
Cost benefit analysis of measures to reduce industrial effluent discharges
Authors: Sivard Åsa , Ericsson Tomas , Hylander Nippe , Karlsson Magnus , Malmaeus Mikael
Published: October 2010

In an environmentally harmonized society the most cost effective measures to reduce the total effluent discharges should be taken into account. Generalised discharge values are presented for organic material and nutrients in this paper. Depending on conditions in the receiving water any of these parameters can be the determining factor for the eutrophication and oxygen demand. These parameters can be generalized into equivalent loads of TOC, nitrogen or phosphorus by recalculation according to the Redfield ratio. The cost for reduction of organic material and nutrients from a pulp and paper mill is calculated as a cost per unit pollutant (cost equivalent). This cost equivalent is compared with alternative costs, expressed in the same way, for reduction of organic material and nutrients in adjacent industries, municipal treatment plants, impact from transportation, farming, air deposits etc. In order to find where the most cost efficient measures for the society should be taken the cost equivalent for the mill is compared with the alternative measures and their equivalent costs.