Pyraclostrobin Removal in Pilot-Scale Horizontal Subsurface Flow Constructed Wetlands and in Porous Media Filters

Georgios D. Gikas,Zisis Vryzas,Ioannis Karametos,Vassilios A. Tsihrintzis

doi:10.3390/pr10020414

Abstract

Pyraclostrobin is a fungicide extensively used for the control of various fungal diseases and is frequently detected in environmental samples. Natural systems, such as constructed wetlands (CWs) and gravity filters, are effective and environmentally friendly treatment systems, which can reduce or eliminate pesticides from the environment. The aim of this study was to investigate the capacity of two pilot-scale CWs (porous media: cobbles and fine gravel, planted with Phragmites australis) and six gravity filters (filling material: bauxite, carbonate gravel and zeolite) to remove pyraclostrobin from polluted water originating from spraying equipment rinsing sites. For this, experiments were conducted to test the performance of the above natural systems in removing this fungicide. The results showed that the mean percent pyraclostrobin removal efficiencies for cobbles and fine gravel CW units were 56.7% and 75.2%, respectively, and the mean percent removals for HRTs of 6 and 8 days were 68.7% and 62.8%, respectively. The mean removal efficiencies for the bauxite, carbonate gravel and zeolite filter units were 32.5%, 36.7% and 61.2%, respectively, and the mean percent removals for HRTs 2, 4 and 8 days were 39.9%, 43.4% and 44.1%, respectively. Regarding the feeding strategy, the mean removal values of pyraclostrobin in gravity filter units were 43.44% and 40.80% for continuous and batch feeding, respectively. Thus, these systems can be used in rural areas for the treatment of spraying equipment rinsing water.

Highlights

Modern agriculture depends on the use of pesticides to increase crop yields, but their residues may pose a serious threat to aquatic and terrestrial ecosystems
Pyraclostrobin is a strobilurin fungicide discovered by BASF in 2000; it has been registered to protect grapes, peppers, tomatoes, wheat, potatoes, sugarbeets, carrots and soybeans against diseases caused by ascomycetes, basidiomycetes, deuteromycetes, and oomycetes [4]
The aim of this study was to investigate the removal efficiency of pyraclostrobin originating from spraying equipment rinsing sites by the use of the following: two mature pilot-scale constructed wetlands (CWs) containing fine gravel and cobbles as porous media, planted with common read (Phragmites australis); and six gravity filters with filling materials of bauxite, carbonate gravel and zeolite

Summary

Introduction

Modern agriculture depends on the use of pesticides to increase crop yields, but their residues may pose a serious threat to aquatic and terrestrial ecosystems. The amounts of fungicides applied to large-scale crops have increased rapidly over the last two decades [1]. Pyraclostrobin is a strobilurin fungicide discovered by BASF in 2000; it has been registered to protect grapes, peppers, tomatoes, wheat, potatoes, sugarbeets, carrots and soybeans against diseases caused by ascomycetes, basidiomycetes, deuteromycetes, and oomycetes [4]. The main mode of action of pyraclostrobin involves the inhibition of mitochondrial respiration by blocking the electron transfer at the outer side of the cytochrome-bc complex. Pyraclostrobin application is related to the activation of the physiological regulation of plants and the promotion of plant growth [5,6].

Objectives

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Results

Conclusion