Conditioning sulfidic mine waste for growth of Agrostis capillaris—impact on solution chemistry

Abstract

Contamination of the environment due to mining and mineral processing is an urgent problem worldwide. It is often desirable to establish a grass cover on old mine waste since it significantly decreases the production of leachates. To obtain sustainable growth, it is often necessary to improve several properties of the waste such as water-holding capacity, nutrient status, and toxicity. This can be done by addition of organic materials such as wood residues, e.g., compost. In this study, we focus on the solution chemistry of the leachates when a substrate containing historic sulfidic mine waste mixed with 30 % (volume) bark compost is overgrown by Agrostis capillaris. The pot experiments also included other growth-promoting additives (alkaline material, mycorrhiza, and metabolizable carbon) to examine whether a more sustainable growth could be obtained. Significant changes in the plant growth and in the leachates composition were observed during 8 weeks of growth. It was concluded that in this time span, the growth of A. capillaris did not affect the composition of the leachates from the pots. Instead, the composition of the leachates was determined by interactions between the bark compost and the mine waste. Best growth of A. capillaris was obtained when alkaline material and mycorrhiza or metabolizable carbon was added to the substrate.

Leachate and contact test with Lepidium sativum L. to assess the phytotoxicity of waste

“…Many substances in waste leachate may be phytotoxic (Sjöberg et al 2014;Machado et al 2016;Gu et al 2018;Sharma et al 2018). Their toxicity depends on the concentration in the leachate.…”

“…Although the physicochemical analyses of waste deliver much information about their toxicity, this information is not enough to evaluate the potential impacts on biota. Complementary phytotoxicity tests are usually used to assess the toxicity of waste (Sjöberg et al 2014;Machado et al 2016;Gu et al 2018;Sharma et al 2018). Phytotoxicity is defined Editorial responsibility: Agnieszka Galuszka.…”

UMBRELLA: Using MicroBes for the REgulation of heavy metaL mobiLity at ecosystem and landscape scAle

“…The soil conditions, microbial additions, Fig. 1 Conceptual drawing combining measures of integrated management of AMD sites and plant choice are decisive factors determining whether metal uptake or exclusion prevails (Sjöberg et al 2014).…”