Municipal sewage sludge as a source of microelements in sustainable plant production: a laboratory lysimeter study

Vanda Adamcová,Marcela Gubišová,Jozef Gubiš,Silvia Dulanská,Katarína Ondreičková,Miroslav Horník,Martin Valica

doi:10.36547/nbc.1258

Abstract

The aim of the work was to characterize the samples of sewage sludge (SSL) originated from the Wastewater Treatment Plant Piešťany (TAVOS, a.s., Trnava, Slovakia) in terms of their potential application into the soils. Within the physico-chemical characterization of SSL, the samples were analysed in terms of the values of pH, cation exchange capacity (CEC), total organic carbon (TOC), water holding capacity (WHC), as well as the presence of heavy metals. It was found that SSL contained significant amounts of microelements Zn (1,269 mg.kg-1, d.w.) and Cu (224 mg.kg-1, d.w.). Laboratory lysimeter experiments involving the application of SSL into the top layer of agriculturally used soil (0 – 10 cm) forming a soil column, in which seedlings of tobacco (Nicotiana tabacum L.) were cultivated, showed that in the case of SSL application in the highest permitted amounts (15 t.ha-1) only 0.11 % Zn and 0.07 % Cu were released into the soil eluate during a 28 day of exposure, while in tobacco plants 0.13 % Zn and 0.05 % Cu were accumulated from the total amount of Zn and Cu originated from the application of SSL (Zn – 133 mg and Cu – 23.5 mg). When applying SSL in amount 30 t.ha-1 i.e., in the dose exceeding the permitted limits, only 0.02 % Zn and 0.04 % Cu were released into the soil eluate and 0.16 % Zn and 0.09 % Cu were accumulated in tobacco plants from the applied amount of SSL (Zn – 267 mg and Cu – 47.0 mg).

Highlights

Sewage sludge (SSL) represent large-volume wastes annually produced in the whole world
From the comparison of the values of physicochemical parameters pH, cation-exchange capacity (CEC) and total organic carbon (TOC) (Table 1) it is clear that the samples of sewage sludge (SSL) and samples of agriculturally used soil (AUS) differed significantly in these evaluated parameters
It can be assumed that the addition of the studied SSL to soils can have a positive effect in terms of increasing the CEC and TOC values of soils, as well as improving the characteristics of the soils important, especially from the point of view of agricultural production

Summary

Introduction

Sewage sludge (SSL) represent large-volume wastes annually produced in the whole world. Nova Biotechnol Chim (2021) 20(2): e1258 terms of the type of wastewater treatment, and is variable and unpredictable as well In this way the public concern and definition of regulations or directives are primarily associated with toxic metals, organic xenobiotics or pathogens occurrence in this type of wastes (Zhang et al 2017). All these factors play an important role in decision with regard to the ultimate SSL disposal, which can involve: composting, landfilling, agricultural application, as well as sea or surface waters disposal and incineration (Donatello and Cheeseman 2013). Subsequent laboratory lysimeter experiments were focused on the total balance of the movement of metals – microelements Zn and Cu occurring in significant amounts in the obtained samples of SSL within the soil biosystem defined by SSL/AUS – soil solution – root system and aboveground parts of tobacco (Nicotiana tabacum L.) plants as a model of fast-growing crops

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