Conditional Order-m Efficiency of Wastewater Treatment Plants: The Role of Environmental Factors

The growing economic and environmental importance of managing water resources at a global level also entails greater efforts and interest in improving the functioning and efficiency of the increasingly more numerous wastewater treatment plants (WWTPs). In this context, this study analyzes the efficiency of a uniform sample of plants of this type located in the region of Valencia (Spain). The type of efficiency measure used for this (conditional order-m efficiency) allows continuous and discrete contextual variables to be directly involved in the analysis and enables the assessment of their statistical significance and effect (positive or negative). The main findings of the study showed that the quality of the influent water and also the size and age of the plants had a significant influence on their efficiency levels. In particular, as regards the effect of such variables, the findings pointed to the existence of an inverse relationship between the quality of the influent water and the efficiency of the WWTPs. Also, a lower annual volume of treated water and more modern installations showed a positive influence. Additionally, the average efficiency levels observed turned out to be higher than those reported in previous studies.

Quality management, environmental management and firm performance in the Spanish hotel industry

Comunicación presentada en el XVI Simposio Internacional de Turismo y Ocio, ESADE, 23 mayo 2007.

Reduction of emerging micropollutants, organic matter, nutrients and salinity from real wastewater by combined MBR–NF/RO treatment

To study the possibility of producing better water quality from municipal wastewater, a membrane bioreactor (MBR) pilot plant with flat sheet (FS) and hollow fiber (HF) membranes coupled with another pilot plant equipped with nanofiltration (NF)/reverse osmosis (RO) membranes were operated to treat municipal wastewater from the wastewater treatment plant (WWTP) Rincón de León, Alicante (Spain). This study was focused on improving the quality of the permeate obtained from the MBR process when complemented by NF or RO stages with respect to salinity, organic matter and nutrients. Furthermore, the removal efficiencies of 10 EMPs were evaluated, comparing the reductions achieved between the wastewater treatment by MBR (adsorption to sludge and biodegradation) and the later treatment using NF or RO (mainly size exclusion). The results showed that the high quality of water was obtained which is appropriate for reuse with salinity removal efficiencies higher than 97%, 96% for total organic carbon (TOC), 91% for nitrates View the MathML sourceNO3- and 99% for total phosphorous (TP). High removal efficiencies were obtained for the majority of the analyzed EMP compounds.

Biodiesel production by transesterification of sludge in supercritical conditions

In this study wastewater treatment plant (WWTP) sludge was subjected to a reactive pyrolysis treatment to produce a high quality pyro-oil. Sludge was treated in supercritical conditions in the presence of methanol using hexane as cosolvent in a high pressure lab-autoclave. The variables affecting the pyro-oil yield and the product quality, such as mass ratio of alcohol to sludge, presence of cosolvent and temperature, were investigated. It was found that the use of a non-polar cosolvent (hexane) presents advantages in the production of high quality pyro-oil from sludge: increase of the non-polar pyro-oil yield and a considerable reduction of the amount of methanol needed to carry out the transesterification of fatty acids present in the sludge.

Donación voluntaria de sangre de cordón umbilical en el Hospital Universitario Virgen de la Arrixaca (2010-2011). Situación actual e influencia de las variables obstétrico-fetales

Objetivos: A principios de 2010 el Hospital Universitario Virgen de la Arrixaca puso en marcha, en el servicio de partos, el protocolo de donación voluntaria de sangre de cordón umbilical (SCU). Desde la reflexión y la autoevaluación, planteamos un análisis de nuestra situación actual a través del estudio de la influencia de las variables obstétrico-fetales en la calidad de las muestras. Métodos: Con este fin hemos planteado un trabajo de tipo observacional, descriptivo, retrospectivo y de corte transversal desde mayo de 2010 a noviembre de 2011, con el objetivo de aumentar la calidad de las unidades de SCU y optar por una gestión eficiente que haga sostenible el proyecto. Resultados: Se obtuvieron 123 donaciones potenciales de sangre de cordón y del análisis multivariable de las mismas obtuvimos una correlación positiva significativa entre el número de leucocitos, las semanas de gestación y el parto vaginal. El peso inicial de la unidad se incrementó significativamente a mayor peso del recién nacido y paridad de la donante. Conclusiones: Como conclusiones del estudio nos planteamos esbozar posibles factores predictivos que permitan seleccionar las muestras de mayor calidad y sean complemento de los actuales estándares elaborados por el Banco Público de Málaga. En este sentido nuestros resultados sugieren que en los partos con más semanas de gestación, paridad de la gestante y peso del recién nacido, así como en los partos vaginales, encontramos mayores posibilidades de obtener muestras de alta calidad.

Quality Management, Environmental Management and Organizational Design in the Hotel Industry: A Qualitative Study

The purpose of this paper is twofold. First, the paper analyzes the relationship between quality management and environmental management and their effects on hotel performance. Second, the article examines the relationship between these two management systems and organizational design. The paper uses an exploratory, qualitative approach based on interviews with managers and experts in the hotel industry. Based on a content analysis of interviews, the results lead to several propositions. Specifically, quality and environmental management influence hotel performance through mediating variables. Moreover, the implementation of quality management facilitates the implementation of environmental management. Furthermore, the implementation of these two management systems is associated with an increase of formalization and decentralization. The paper contributes to the analysis of quality management, environmental management, organizational design and performance in a joint manner, which has not been attempted before in the hotel industry. In addition, it helps extend the findings about these links in manufacturing and service organizations to the hotel industry.

Quality certification, performance and size in hotel chains

This paper examines the relationship between quality certification and performance, and quality certification and size in hotel chains operating in Spain. In an initial phase, a quantitative study is made with secondary and objective data to analyse these relationships. In a second phase, a qualitative analysis is applied to reach a better understanding of the quantitative results. The findings show that chains with certified hotels achieve better performance levels; that better performance levels increase with the percentage of certified hotels within the chain; and that quality certification has positive effects on some performance variables. In addition, size is not a key factor for certification, although it could be an enabler.

A three-stage DEA model to evaluate learning-teaching technical efficiency: Key performance indicators and contextual variables

This study evaluates the technical efficiency of the learning-teaching process in higher education using a three-stage procedure that offers advances in comparison to previous studies and improves the quality of the results. First, it utilizes a multiple stage Data Envelopment Analysis (DEA) with contextual variables. Second, the levels of super efficiency are calculated in order to prioritize the efficiency units. And finally, through sensitivity analysis, the contribution of each key performance indicator (KPI) is established with respect to the efficiency levels without omission of variables. The analytical data was collected from a survey completed by 633 tourism students during the 2011/12, 2012/13 and 2013/14 academic course years. The results suggest that level of satisfaction with the course, diversity of materials and satisfaction with the teacher were the most important factors affecting teaching performance. Furthermore, the effect of the contextual variables was found to be significant.

Organizational design, quality management and competitive advantage in hotels

Purpose – The aim of this study is to examine the relationship between practices of quality management (QM) and the characteristics of organizational design, and QM and competitive advantage. Design/methodology/approach – The study uses a partial least squares approach to test these relationships in 350 hotels in Spain. Findings – The findings show that QM influences specialization, formalization and interdepartmental interactions, and that QM practices influence both cost and differentiation competitive advantage. The results also indicate the importance of QM strategic and operational systems as practices that have a key impact on the characteristics of organizational design. Similarly, the QM operational system is key in the relationship between QM and cost competitive advantage. Finally, the QM operational, information and strategic systems positively influence differentiation competitive advantage. Practical implications – When hotels adopt QM practices, there will be significant changes in a number of organizational variables, including specialization, formalization and interdepartmental interactions. This paper provides empirical evidence that QM practices improve both cost and differentiation competitive advantage in the hotel industry. Originality/value – There has been little research on the effects of QM on organizational design in the hotel industry. The contribution of this paper is that analyze the effects of QM on organizational design and competitive advantage, extending knowledge about these issues in a specific sector.