27 research outputs found

    Integrity Model Application: A Quality Support System for Decision-makers on Water Quality Assessment and Improvement

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    In this paper, a mathematical model has been applied to a river in North-East Italy to describe vulnerability scenarios due to environmental pollution phenomena. Such model, based on the influence diagrams theory, allowed identifying the extremely critical factors, such as wastewater discharges, drainage of diffuse pollution from agriculture and climate changes, which might affect the water quality of the river. The obtained results underlined how the water quality conditions have improved thanks to the continuous controls on the territory, following the application of Water Framework Directive 2000/60/EC. Nevertheless, some fluvial stretches did not reach the "good ecological status" by 2015, because of the increasing population in urban areas recorded in the last years and the high presence of tourists during the summer months, not balanced by a treatment plants upgrade

    Discharge quality from municipal wastewater treatment plants and the Sludge Biotic Index for activated sludge: integrative assessment

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    Abstract Wastewater treatment plants (WWTPs) are scrutinized by Environmental Authorities particularly regarding the compliance to discharge limit values fixed by national and local regulations. An integrated approach is necessary to achieve the objectives established with Directive 2000/60/EC (WFD) considering the ecological status of the receiving water body and the quality of the discharge. Specifically, documentary, technical, management and analytical controls should be developed. Moreover, integrative information on the behaviour of the activated sludge in the aeration tank can be useful for plant managers as well as for the regulating Authorities. The study presents the experience concerning WWTP regulation considering the analytic assessment of the discharge as well the monitoring of the Sludge Biotic Index (SBI) for activated sludge. Data from monitoring during the period 2008–14 on SBI values and chemical and microbiological data on the discharges of a sample of 35 WWTPs in the province of Venice (north-east Italy, Veneto region) are presented and discussed. Together with chemical and microbiological analysis, the SBI appears to be a highly useful index for the integrative assessment of plant functionality, in particular when monitoring and identifying critical situations that can determine the exceedance of discharge limit values. The SBI method, in an integrated control approach, can be used for small and medium sized WWTPs that only treat domestic wastewaters. In a case by case assessment this may even substitute part of the analytical monitoring carried out in the WWTPs' control process

    Trace elements: critical insights from 15 years of monitoring in the Venice Lagoon catchment basin (Italy)

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    The study focused on selected trace elements (As, Cd, Cr, Hg, Ni, Pb) monitored in surface waters of the Venice Lagoon catchment basin (North East Italy) over the period 2000-2015. The monitoring was undertaken to verify the achievement of the quality objectives set by the European and national legislations. The available results have been analyzed to evaluate the chemical status of water bodies. The limit of quantification (LOQ) of the applied analytic techniques appears critical for the adequate water monitoring; for some parameters, the percentage of not visible values due to non-satisfactory LOQ was higher in the beginning of the period; the subsequent improvement of LOQ allowed assessing the respect of environmental quality standards (EQSs). The study analyzes time trends in single stations and the differences between detected concentrations in the considered stations. Moreover, maximum concentrations and water flows have been considered to understand the potential correlation. Cumulated frequency curves for the most critical parameters have been built to identify situation of potential overtaking of the EQSs in force. The most polluted sampling stations of the drainage basin for the six trace elements were found in Cuori and Fiumazzo rivers. Although LOQs changed over time, the recorded trends show a quality improvement and a good compliance with respect to EQSs set by European legislation, while considering EQSs set by local special legislation, the objectives are not yet satisfied. Arsenic is ubiquitous; thus, it can be supposed to be originated as a background environmental concentration, while nickel appears of industrial origin according to its point and local presence

    MIMR criterion application: Entropy approach to select the optimal quality parameter set responsible for river pollution

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    Surface water quality has a vital role when defining the sustainability of the ecological environment, public health, and the social and economic development of whole countries. Unfortunately, the rapid growth of the worldwide population together with the current climate change have mostly determined fluvial pollution. Therefore, the employment of effective methodologies, able to rapidly and easily obtain reliable information on the quality of rivers, is becoming fundamental for an efficient use of the resource and for the implementation of mitigation measures and actions. TheWater Quality Index (WQI) is among the most widely used methods to provide a clear and complete picture of the contamination status of a river stressed by point and diffuse sources of natural and anthropic origin, leading the policy makers and end-users towards a more and more correct and sustainable management of the water resource. The parameter choice is one of the most important and complex phases and recent statistical techniques do not seem to show great objectivity and accuracy in the identification of the real water quality status. The present paper offers a new approach, based on entropy theory and known as the Maximum Information Minimum Redundancy (MIMR) criterion, to define the optimal subset of chemical, physical, and biological parameters, describing the variation of the river quality level in space and time and thus identifying its pollution sources. An algorithm was implemented for the MIMR criterion and applied to a sample basin of Northeast Italy in order to verify its reliability and accuracy. A comparison with the Principal Component Analysis (PCA) showed how the MIMR is more suitable and objective to obtain the optimal quality parameters set, especially when the amount of investigated variables is small, and can thus be a useful tool for fast and low-cost water quality assessment in rivers

    Surface water vulnerability assessment applying the integrity model as a decision support system for quality improvement

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    The implementation of the Water Framework Directive (WFD) 2000/60/EC, aimed at achieving a “Good” Ecological Status of surface water bodies by 2015, indicates the adoption of a River Basin Management approach by using a model which works as a support for decision making. This work has applied the suggestions put forward by the WFD by means of a mathematical model called the Integrity Model. This represents valid support when assessing the efficiency of planned interventions which may directly or indirectly play a role in enhancing the quality of surface waters at the basin scale. Herein the results of a preliminary application limited to just two indexes on the Bacchiglione river basin, located in Northern Italy, are both presented and compared with the results of institutional monitoring activities in compliance with set technical regulations. The proposed model appears to be useful when carrying out Strategic Environmental Assessment (SEA) procedures in accordance with Directive 2001/42/EC concerning water management and protection plans as well as for the Environmental Impact Assessment (EIA) procedure to be carried out on the interventions identified

    Modello di integrità per le acque superficiali: applicazione al bacino del fiume Bacchiglione

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    L’implementazione della direttiva 2000/60/CE (WFD) per raggiungere un stato ecologico buono per i corpi idrici superficiali entro il 2015 suggerisce di seguire un approccio di gestione a livello di pianificazione di bacino utilizzando un modello che funzioni come supporto alle decisioni (ad esempio modello DPSIR – Forzanti, Pressioni, Stato, Impatti, Risposte). Lo stato delle acque dovrebbe essere monitorato in funzione del modello e le sorgenti di pressione sul corpo idrico dovrebbero essere controllate sulla base degli impatti antropici identificati. In questo lavoro le indicazioni della WFD sono state interpretate sviluppando un modello matematico definito “Modello di Integrità” che rappresenta un valido supporto per valutare l’efficacia degli interventi pianificati che possono giocare, direttamente o indirettamente, un ruolo nel miglioramento della qualità delle acque superficiali a scala di bacino. Nel lavoro vengono presentati i risultati di una applicazione preliminare limitata all’analisi di un solo indice al bacino del fiume Bacchiglione (Italia)
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