Abandoned coal mining sites: using ecotoxicological tests to support an industrial organic sludge amendment

Abstract

The different stages involved in coal mining-related activities result in a degraded landscape and sites associated with large amounts of dumped waste material. Remediation of these contaminated soils can be carried out by application of industrial organic sludge if the concerns regarding the potential negative environmental impacts of this experimental practice are properly addressed. In this context, the objective of this study was to use ecotoxicological tests to determine the quantity of organic industrial sludge that is required as a soil amendment to restore soil production while avoiding environmental impact. Chemical analysis of the solids (industrial sludge and soil) and their leachates was carried out as well as a battery of ecotoxicity tests on enzymes (hydrolytic activity), bacteria, algae, daphnids, earthworms, and higher plants, according to standardized methodologies. Solid and leachate samples of coal-contaminated soil were more toxic than those of industrial sludge towards enzyme activity, bacteria, algae, daphnids, and earthworms. In the case of the higher plants (lettuce, corn, wild cabbage, and Surinam cherry) the industrial sludge was more toxic than the coal-contaminated soil, and a soil/sludge mixture (66:34% dry weight basis) had a stimulatory effect on the Surinam cherry biomass. The ecotoxicological assessment of the coal-contaminated soil remediation using sludge as an amendment is very important to determine application rates that could promote a stimulatory effect on agronomic species without negatively affecting the environment.

Effect of the acclimation of a Streptomyces consortium on lindane biodegradation by free and immobilized cells

“…A phytotoxicity test using Lactuca sativa (lettuce) was performed since it is a versatile tool to assess the potential environmental impact, allowing the identification of the effect of pollutants present in the matrix, as well as to monitor the success of a remediation process [22]. For this purpose, 30 seeds were grown in Petri dishes containing sterile filter paper (Wattman No.…”

Enhanced lindane removal from soil slurry by immobilized Streptomyces consortium

“…Phytotoxicity tests are versatile tools for monitoring the success of a remediation process (Chiochetta et al 2013). For this purpose, lettuce seeds were cultured in aliquots of bioremediated diluted slurries, taken at different times.…”

Soil ecotoxicology in Latin America: Current research and perspectives

“…Furthermore, risk of runoff and possible toxic effects on adjacent aquatic ecosystems should be considered in risk assessments of soil disposal of these residues . Assessment endpoints should include the soil retention function using soil extracts/eluates and aquatic organisms . Freitas and Rocha highlighted the risks of sodium and potassium runoff for tropical freshwater biota, in areas next to soils with intensive application of fertilizers or ferti‐irrigation with vinasses (byproduct of the sugar‐cane industry used as a soil amendment).…”