Identification and Assessment of Groundwater and Soil Contamination from an Informal Landfill Site

Abstract

Landfills are a potential source of local environmental pollution of all kinds, and the gradual destruction of seepage-proof structures in informal landfills will lead to contamination of the surrounding soil and groundwater environment. In this study, an informal landfill site in eastern China is used as the research object. Using technologies such as unmanned vessels and monitoring well imaging to delineate the amount and distribution of polluting media, sampling of the surrounding soil, sediment, groundwater, and surface water for testing, analysis, and evaluation is carried out visually and finely for heavy metals, petroleum hydrocarbons, volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), and other indicators. The test results show that volatile phenols are the main contaminant species in the shallow groundwater, chlorinated hydrocarbons and benzene were prevalent in the deep groundwater, hexachlorobenzene and lead in the surface soil, and di(2-Ethylhexyl) phthalate in the deep soil (5.5 m), with a maximum exceedance of 1.24 times. Nearly 10 years have passed since the waste dumping incident at the landfill, but characteristic contaminants are still detected in the topsoil of the dumping area, which shows the long-term nature of the environmental impact of illegal dumping on the site. The study recommends that when developing a comprehensive remediation plan, the persistence of the environmental impact of the waste should be considered and appropriate remediation measures should be screened.

Carbon and Sulfur Isotope Methods for Tracing Groundwater Contamination: A Review of Sustainable Utilization in Reclaimed Municipal Landfill Areas

“…When collecting a water sample is possible, the simplest way is to measure the physicochemical composition of water (i.e., its specific electrical conductivity (SEC)), mineralization, the concentration of major ions (HCO 3 − , Cl − , NO 3 − , Ca 2+ , Mg 2+ , Na + , and K + ), other components (e.g., heavy metals), and some minor and trace elements (multivariate analysis). These are then compared with the hydrogeochemical background range, the quality standards for groundwater, or assessments of human health risk [13,14,[43][44][45][46][47][48][49][50]. Evidence of contamination is the presence of BTEX, PAHs, pesticides, micro-and nanoplastics, xenobiotic organic compounds, pharmaceutical compounds, specific substances (per-/polyfluoroalkyl substances), and other components that do not form in the natural environment [19,47,[51][52][53][54][55].…”

Enhanced Soil Decontamination via Electrokinetic Removal of Organic Pollutants

“…Bioremediation is a process that makes use of microbes in soil to treat or degrade the organic contaminants into low toxic or unharmful through biostimulation and bioaugmentation. Biostimulation is a method that stimulates the native microorganisms or microbes in soil by adding or introducing oxygen (bioventing), water, nutrients, or electron acceptors [42]. Other than that, bioaugmentation is a method that increases the existing microbes in soil by adding the existing microbes or non-indigenous to improve the remediation in contaminated areas [42].…”

“…Biostimulation is a method that stimulates the native microorganisms or microbes in soil by adding or introducing oxygen (bioventing), water, nutrients, or electron acceptors [42]. Other than that, bioaugmentation is a method that increases the existing microbes in soil by adding the existing microbes or non-indigenous to improve the remediation in contaminated areas [42]. In short, biostimulation is to add external factors to stimulate the microbes whereas bioaugmentation is to increase the concentration of microbes through the addition of native or non-native microbes.…”

Critical Study Quality Management for the Anti-Seepage System in Macau’s Landfill Area

“…In landfill anti-seepage system projects, environmental factors and engineering conditions may change. Adopting agile methods can better address these variations [7].…”