Levels of Organic Pollution Indicators in Groundwater at the Old Landfill and Waste Management Site

Eugeniusz Koda,Anna Miszkowska,Anna Sieczka

doi:10.3390/app7060638

Eugeniusz Koda, Anna Miszkowska + Show 1 more

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https://doi.org/10.3390/app7060638

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Journal: Applied Sciences	Publication Date: Jun 20, 2017
Citations: 59	License type: CC BY 4.0

Affiliation: Warsaw University of Life Sciences

Abstract

The aim of this paper was to assess groundwater quality in a landfill and waste management site, with special regard to levels of organic pollution indicators: chemical oxygen demand (COD), biochemical oxygen demand (BOD), and total organic carbon (TOC). Analysis of specific indicators was conducted for piezometers located in the area of the Radiowo landfill, the composting plant and the facilities adjacent to the landfill. The article discusses the temporal and spatial changes of selected organic pollution indicators. Based on the results of groundwater monitoring, several maps of COD, BOD and TOC areal distribution were provided. Statistical distribution of monitoring data was presented using box-and-whisker plots. Pearson’s correlation coefficients between selected pollution indicators were measured with a significance level set at p < 0.01 and p < 0.05. The strongest correlation was observed between BOD and COD. The maximum BOD/COD ratio was observed at the level of 1.561 before the closure of the vertical barrier, whereas, at present, average values of this ratio are below 0.18. The results indicate significant improvement of groundwater quality in the landfill site after the closure of the vertical barrier. In particular, this refers to BOD values, which decreased even 160 times in the 1998–2016 monitoring period.

Highlights

Nowadays, landfilling is the most common practice of waste disposal all over the world [1,2].In 2015, a total of 10.9 million tons of municipal solid wastes were collected in Poland, of which 44.3%were landfilled in 347 operating landfills [3].Landfill leachate is considered the main source of groundwater and surface water contamination.In recent decades, the influence of leachates on water resources has attracted a lot of attention because of its high environmental significance [4,5]
According to Christensen et al [1], the components of leachates can be subdivided into the following groups: organic matter expressed as chemical oxygen demand (COD) and total organic carbon (TOC), specific organic compounds, inorganic compounds, and heavy metals
Owing to the fact that groundwater quality within the landfill site should be controlled by a monitoring system based on a network of piezometric wells and sampling points located along surface streams near the landfills, this study focuses on detailed analyses using data from a monitoring period of almost 20 years (1998–2016)

Summary

Introduction

Landfill leachate is considered the main source of groundwater and surface water contamination. The influence of leachates on water resources has attracted a lot of attention because of its high environmental significance [4,5]. Leachates mainly contain immense amounts of organic matter, ammonium, heavy metals, and salts [6,7,8]. According to Christensen et al [1], the components of leachates can be subdivided into the following groups: organic matter expressed as chemical oxygen demand (COD) and total organic carbon (TOC), specific organic compounds, inorganic compounds, and heavy metals. Leachates are commonly characterized by high chemical and biochemical oxygen demand values (COD and BOD, respectively) that reflect concentrations of soluble organic matter

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