Screening Life Cycle Environmental Impacts and Assessing Economic Performance of Floating Wetlands for Marine Water Pollution Control

Vasileios Takavakoglou,Eleanna Pana,Konstantinos V Plakas,Apostolos Georgiadis,Dimitrios K Karpouzos,Pantazis E Georgiou

doi:10.3390/jmse9121345

Abstract

The growing environmental awareness of society, the advancement of nature-based solutions (NbSs), and the need for reliable and cost-effective solutions create a favorable environment of opportunities for floating wetlands as alternative solutions for marine water pollution control. The aim of this work was to screen, through OpenLCA, the environmental impacts of floating wetlands for marine water pollution control at various life cycle stages of the system, and assess its economic performance and contribution to the welfare of society. The stage of raw materials production and acquisition was found to be responsible for the main environmental impacts of the floating wetlands, especially on global warming potential, whereas the main impact of the operational stage was related to the eutrophication potential due to N and P residuals in the effluent. The economic performance indicators of economic net present value (ENPV), economic rate of return (ERR), and benefits/costs ratio (B/C ratio) indicate, although marginally, that floating wetlands may constitute a viable investment with potential positive socioeconomic impacts. However, there are still several scientific challenges and technical issues to be considered for the operational application of such systems at full-scale in marine environments.

Highlights

Marine life is heavily threatened by pollution and habitat degradation, mostly due to human activities, such as ship traffic, fisheries, and coastal zone activities, whose impacts are exacerbated by climate change
The screening of environmental impacts at various life cycle stages of a floating wetlands system for marine water pollution control was based on the life cycle assessment approach, which consists of the following steps: system description; setting the goal and scope of Life cycle assessment (LCA); identification of the system boundaries; inventory of inflows and outflows; assessment of impacts; and sensitivity analysis of results
In the Floating wetlands (FWs) system under study, the characterization results (Table 3) indicate that abiotic depletion potential (ADP), acidification potential (AP), global warming potential (GWP), ozone layer depletion potential (ODP), and human toxicity potential (HTP) are mainly affected by the stage of raw materials production and acquisition

Summary

Introduction

Marine life is heavily threatened by pollution and habitat degradation, mostly due to human activities, such as ship traffic, fisheries, and coastal zone activities (agricultural, industrial, and urban), whose impacts are exacerbated by climate change. Conventional treatment plants and techniques offer feasible methods for treating saline wastewater These methods are ineffective in controlling diffuse pollution, and most of them use sophisticated equipment, which require large economic investments, and consume vast amounts of energy [2]. These drawbacks urge the scientific community to search for creative, cost effective, and environmentally sound ways to control marine water pollution [3]. Floating wetlands (FWs) are a promising and cost-effective eco-engineering tool to restore waterbodies [4] They are gaining acceptance as a type of constructed wetland that can be applied within an existing natural or artificial water body, and withstand water level fluctuations and adverse conditions. Compared to conventional types of constructed wetlands, the biological processes are more effective in FWs due to the free suspension of roots in the water column—this establishes direct contact between contaminants and the root-associated microbial community [7]

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Conclusion