Search results for "WASTE"

Assessment of wastewater treatment plant design for small communities: Environmental and economic aspects

2012

The preliminary design and economic assessment of small wastewater treatment plants (less than 2000 population equivalent) are issues of particular interest since wastewaters from most of these agglomerations are not covered yet. This work aims to assess nine different technologies set-up for the secondary treatment in such type of facilities embracing both economic and environmental parameters. The main novelty of this work is the combination of an innovative environmental decision support system (EDSS) with a pioneer approach based on the inclusion of the environmental benefits derived from wastewater treatment. The integration of methodologies based on cost-benefit analysis tools with th…

Assessment of wastewater treatment alternatives for small communities: An analytic network process approach

2015

The selection of the most appropriate wastewater treatment (WWT) technology is a complex problem since many alternatives are available and many criteria are involved in the decision-making process. To deal with this challenge, the analytic network process (ANP) is applied for the first time to rank a set of seven WWT technology set-ups for secondary treatment in small communities. A major advantage of ANP is that it incorporates interdependent relationships between elements. Results illustrated that extensive technologies, constructed wetlands and pond systems are the most preferred alternatives by WWT experts. The sensitivity analysis performed verified that the ranking of WWT alternatives…

Pollutant removal efficiency of a pilot-scale Horizontal Subsurface Flow in Sicily (Italy) planted with Cyperus alternifolius L. and Typha latifolia …

2016

Constructed wetland systems (CWs) are developed biological technologies for the treatment and reuse of wastewater. The aims of this study were to evaluate the treatment performance of a pilot Horizontal Subsurface Flow system (HSSFs), to evaluate the reuse of treated wastewater (TWW) from CWs for the irrigation of giant reed (Arundo donax (L.)) and to assess the effects of TWW on the biomass yield of giant reed grown for pellet production. The research was carried out in Sicily (Italy) in a pilot-scale HSSFs which was fed with urban-treated urban wastewater following secondary treatment from an activated sludge wastewater treatment plant. Giant reed plots were irrigated with TWW from plante…

The use of constructed wetlands for the treatment and reuse of urban wastewater for the irrigation of two warm-season turfgrass species under Mediter…

2017

Constructed wetlands (CWs) represent low-cost technology for the treatment and reuse of wastewater in urban areas. This study aimed to evaluate the pollutant removal efficiency of a CW system and to assess the effects of irrigation using treated urban wastewater on soil and on two warm-season turf species. The research was carried out in Sicily (Italy) on a pilot-scale horizontal subsurface flow system which was fed with treated urban wastewater following secondary treatment from an activated-sludge wastewater treatment plant. The pilot system was located in an open urban park and comprised two separate parallel planted units. Experimental fields of Cynodon dactylon (L.) Pers. and Paspalum …

How much should customers be compensated for interruptions in the drinking water supply?

2017

Water supply interruptions directly affect customers, and customers should be compensated accordingly. However, few water regulators have applied compensation policies given the difficulty of estimating the economic value of compensation to customers. In this study, a pioneering approach based on the concept of shadow prices is proposed to determine the compensation that customers should receive for unplanned water interruptions. The Chilean water industry was selected as a case study because there is an ongoing policy discussion between the use of penalties or compensation as an incentive to prevent water supply interruptions. The estimated results indicate that for 2014, the value of comp…

Measuring the eco-efficiency of wastewater treatment plants under data uncertainty

2018

Abstract Eco-efficiency assessment is a useful tool for improving the sustainability of wastewater treatment plants (WWTPs). However, it is a complex task that requires the integration of several performance indicators into a single index. Data envelopment analysis (DEA) is established as a highly effective methodology for achieving this as it permits the integration of the service value, resource consumption and environmental impact variables as the desirable outputs, inputs and undesirable outputs, respectively. However, traditional DEA models omit uncertainties in the data that are likely to result in biased conclusions. This study pioneers the assessment of the eco-efficiency of WWTPs w…

Estimating the cost of improving service quality in water supply: A shadow price approach for England and wales

2015

Service quality to customers is an aspect that cannot be ignored in the performance assessment of water companies. Nowadays water regulators introduce awards or penalties to incentivize companies to improve service quality to customers when setting prices. In this study, the directional distance function is employed to estimate the shadow prices of variables indicating the lack of service quality to customers in the water industry i.e., written complaints, unplanned interruptions and properties below the reference level. To calculate the shadow price of each undesirable output for each water company, it is needed to ascribe a reference price for the desirable output which is the volume of w…

Expert control of DO in the aerobic reactor of an activated sludge process

2000

Abstract An expert control structure is proposed for the control of dissolved oxygen (DO) in a Nitrification Denitrification Biological Excess Phosphorus Removal (NDBEPR) plant to account for the several processes that are influenced by the DO concentration in the aerator. In the scheme a supervisory fuzzy controller determines the set point of an inner DO control loop where an Adaptive Robust Generic Model Control (ARGMC) controller is used. The fuzzy supervisory control has a hierarchical structure. Off-line measurements of biological parameters of influent and effluent streams can be used to periodically update the set points of the fuzzy controllers. The complete control scheme has been…

Organic waste materials for Bioengineering works

2016

Bioengineering uses plant and biodegradable materials of natural origin, stones, steel, additives and synthetic products in various combinations and as support for the growth of plants. The lack of available resources and progressive increasing of desertification in Sicily, led to the search for alternative materials. Objective of the work is testing organic waste materials for the realization of bioengineering works in the several areas of application: terrestrial, fluvial and coastline. To this aim, is proposed the use of innovative techniques that involve the construction of low-cost brushwood, environmentally friendly materials made: the pruning of vines and the oceanic Posidonia oceani…

From wastes to resources: citrus hydrolatesas natural biostimulants of soil microorganisms

The hydrolates result from the industrial extraction process of the essential oils through cold pressing of the citrus peels. Today, they are considered a waste to be disposed of. However, due to the presence of water soluble compounds (sugars, polyphenols, acids), hydrolates could be reused instead of being, due to the high economic burden, a problem in the disposal of the same, charged to the company.The aim of this work was to evaluate the effects of citrus hydrolate when directly applied as irrigation water on soil microbial biomass, activity and structure community. The soil used for the experiment was collected from the topsoil (0-10 cm) of a citrus orchard, air-dried and sieved at 2 …