A Comparison of Waste Stability Indices for Mechanical⁻Biological Waste Treatment and Composting Plants.

Andrzej Jędrczak,Monika Suchowska-Kisielewicz

doi:10.3390/ijerph15112585

Abstract

Achieving high efficiency of biological waste treatment in mechanical–biological treatment (MBT) plants requires reliable methods for measuring the degree of biodegradation of organic substances. For this purpose, several physical, chemical, and biological indices are used. This paper presents respirometric activity (AT4), biogas potential (GB21), total and dissolved organic carbon (TOC and DOC, respectively), and loss on ignition (LOI) values, as well as the correlations between the indices selected for stabilized waste produced in 18 MBT plants in Poland, which use various technologies for biological processing of the organic fraction of municipal solid waste. The study confirms that there is a linear relationship between AT4 and GB21 for stabilized waste produced in MBT plants, regardless of the waste treatment technology used. It has also been found that there is a linear relationship between AT4 and the concentration of dissolved carbon in water extract from stabilized waste. This indicates that DOC can be used for monitoring the organic matter stabilization process in mechanical–biological waste treatment plants. Its advantage is a shorter time needed for measurements in comparison to AT4 and GB21 tests.

Highlights

The main objective of the biological process that municipal solid waste (MSW) goes through in mechanical–biological treatment plants (MBT) is the stabilization of biodegradable organic fractions.The purposes of the stabilization are (i) volume reduction, (ii) minimization of structural changes occurring in a landfill, (iii) reduction of biogas production, and (iv) susceptibility to washing out or settling after being deposited
The non-biological methods used for monitoring the course of biological processes include such parameters as the content of organic matter (LOI), total and dissolved organic carbon (TOC and DOC, respectively), chemical oxygen demand (COD), and C/N [1,2,3,4]
The waste samples used in this study consisted of the organic fraction of municipal solid waste (OFMSW) that was produced in a full-scale MBT plant and directed for biological treatment, and the final product of this treatment is called stabilized waste (SW)

Summary

Introduction

The main objective of the biological process that municipal solid waste (MSW) goes through in mechanical–biological treatment plants (MBT) is the stabilization of biodegradable organic fractions.The purposes of the stabilization are (i) volume reduction, (ii) minimization of structural changes occurring in a landfill, (iii) reduction of biogas production, and (iv) susceptibility to washing out or settling after being deposited. Analysis of the efficiency of waste treatment in MBT plants requires reliable methods for measuring the degree of biodegradation of organic substances. This parameter provides valuable information for landfill operators on the acceptability of substrates for final disposal, and makes it possible to assess the efficiency of operating plants, as well as improving biological treatment, designing optimized plants, and determining the potential environmental impact of stabilized waste produced in them. The non-biological methods used for monitoring the course of biological processes include such parameters as the content of organic matter (LOI), total and dissolved organic carbon (TOC and DOC, respectively), chemical oxygen demand (COD), and C/N [1,2,3,4]. LOI, TOC, and DOC are indicators that have traditionally been used to determine the content of organic matter in waste [5]

Objectives

Methods

Conclusion