Comparison between two reactors using Trametes versicolor for agricultural wastewater treatment under non-sterile condition in sequencing batch mode

Kaidi Hu,Montserrat Sarrà,Gloria Caminal

doi:10.1016/j.jenvman.2021.112859

Kaidi Hu, Montserrat Sarrà + Show 1 more

Open Access

https://doi.org/10.1016/j.jenvman.2021.112859

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Abstract

Agricultural wastewater is a major source of herbicides, which pose environmental and health concerns owing to their substantial use and poor elimination rate in conventional wastewater treatment plants. White-rot fungi are versatile in degrading xenobiotics; however, the key problem encountered with their application in actual scenarios is competition with indigenous microorganisms, mainly bacteria. To address this barrier, two different strategies were implemented in the present study. One strategy was to set up a trickle bed with Trametes versicolor immobilized on pine wood, and another strategy was to employ a T. versicolor-pelleted, fluidized-bed reactor to remove diuron and bentazon from actual wastewater under non-sterile conditions. The residence time in the trickle bed was estimated using three methodologies. With 10 batches of a 3-day cycle operation, although the trickle-bed reactor possessed a shorter contact time (8.5 h per cycle) and lower laccase activity compared with those of the fluidized-bed reactor, it demonstrated a higher removal yield and lower bacterial counts. In addition, the utilization of pine wood as a carrier obviously reduced the cost since no additional nutrients were required. Hence, after evaluating all advantages and limitations of both bioreactors, for the purpose of treating over the long term and scaling up, a trickle-bed reactor is the preferred choice.

Highlights

In recent decades, diverse micropollutants that demonstrate persis tence, partly because of their high volumes of production and con sumption resulting from anthropogenic activities and partly because of their poor elimination rates in conventional wastewater treatment plants (WWTPs), have represented a severe global concern, and these micropollutants include pesticides, pharmaceuticals, personal care products, steroid hormones, industrial chemicals and many other emerging compounds (Luo et al, 2014)
To determine the residence time of the trickle-bed reactor (TBR), three different strategies were adopted in this study, and the responses and calculated results are presented in Fig. 2 and Table 1
Similar profiles were ob tained by Saand Boaventura (2001) using siliceous granular material to support the biomass in the TBR

Summary

Introduction

Diverse micropollutants that demonstrate persis tence, partly because of their high volumes of production and con sumption resulting from anthropogenic activities and partly because of their poor elimination rates in conventional wastewater treatment plants (WWTPs), have represented a severe global concern, and these micropollutants include pesticides, pharmaceuticals, personal care products, steroid hormones, industrial chemicals and many other emerging compounds (Luo et al, 2014). Pesticides are considered the main trigger of environmental deterioration, their use addresses the increasing food demand and population explo sion (Meftaul et al, 2020; Rani et al, 2020). As a key component of modern global agricultural systems, herbicide sales account for the largest proportion of agrochemicals and currently for more than 40% of their consumption (Carvalho, 2017).

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