Towards A New Decision Support System for Design, Management and Operation of Wastewater Treatment Plants for the Reduction of Greenhouse Gases Emission

Donatella Caniani,Giovanni Esposito,Giorgio Mannina,Riccardo Gori

doi:10.3390/w7105599

Abstract

The increasing attention paid to the environment has led to a reduction in the emissions from wastewater treatment plants (WWTPs). Moreover, the increasing interest in the greenhouse gas (GHG) emissions from WWTPs suggests that we reconsider the traditional tools used for designing and managing WWTPs. Indeed, nitrous oxide, carbon dioxide and methane can be emitted from wastewater treatment, significantly contributing to the greenhouse gas (GHG) footprint. The reduction of energy consumption as well as GHG emission are of particular concern for large WWTPs which treat the majority of wastewater in terms of both volume and pollution load. Nowadays, there is an increasing need to develop new tools that include additional performance indicators related to GHG emissions and energy consumption as well as traditional effluent quality parameters. Energy consumption, in fact, can be considered as an indirect source of GHGs. This paper presents the development of an ongoing research project aiming at setting-up an innovative mathematical model platform for the design and management of WWTPs. The final goal of the project by means of this platform is to minimize the environmental impact of WWTPs through their optimization in terms of energy consumptions and emissions, which can be regarded as discharged pollutants, sludge and GHGs.

Highlights

In recent years, studies about greenhouse gas (GHG) emissions show that wastewater treatment plants (WWTPs) are anthropogenic GHG potential sources, contributing to climate change and air pollution [1]
Experimental results of the UO1 are reported in Figure 5, which shows the N2O concentration in the off-gas withdrawn from the aerobic and anoxic tank for an membrane bioreactor (MBR) pilot plant
In case of civil wastewater, the effect of the low C/N leads to the increase of N2O production during the nitrification process

Summary

Introduction

Studies about greenhouse gas (GHG) emissions show that wastewater treatment plants (WWTPs) are anthropogenic GHG potential sources, contributing to climate change and air pollution [1]. The reduction of energy consumption as well as monitoring and reduction of GHG emission are of particular concern for large WWTPs which treat the majority of wastewater in terms of both volume and pollution load. WWTPs produce the three major GHGs [2]: carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), from both wastewater and sludge treatment lines, and additional amounts of CO2 and CH4 from the energy demands. GHGs are produced during sludge disposal or reuse (transportation and off-site degradation of biosolids) and off-site production of energy and chemicals. The latest are due to the production of electricity required for pumping, aeration, heating and mixing, production and transportation of fuel and chemicals, as well as transportation, reuse and disposal of solids, and degradation of remaining constituents in the effluent [2]

Objectives

Results

Conclusion