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

Abstract

The study evaluated the use of Lepidium sativum L. to assess the phytotoxicity of three types of waste such as hazardous waste (slags from zinc to copper smelters) and nonhazardous waste (mineral–organic composite). Previous studies evaluated heavy metal leaching and the environmental impact of the tested waste. The purpose of phytotoxicity studies was to increase knowledge about this waste. Two types of tests were used to assess the phytotoxicity of wastes: germination index and accumulation test. Both tests were carried out for leachate (leachate test) and waste (contact test). The results of both tests were compared to assess the phytotoxic effects of tested waste. Phytotoxicity tests have shown that the mineral–organic composite leachate was stimulated plant growth, copper smelter slag leachate was characterized by no phytotoxicity and zinc slag leachate inhibited the growth of plants. In contrast, contact test showed inhibitory effects from all tested waste. Wherefore, the contact test was indicated as more sensitive in the assessment of phytotoxicity. However, this is not a clear assessment, because the germination index values for both tests were a result of differences of root length for both control samples (deionized water and sand). The study confirmed the usefulness of L. sativum for the assessment of phytotoxicity of various types of waste. Additionally, it was found that L. sativum was resistant to high concentrations of heavy metals in the leachate, without causing any negative physiological effects.

Comparison of Landfill Leachate Properties by LPI and Phytotoxicity-A Case Study

“…Low contents of heavy metals (< 1 mg/l) in leachates from active landfills may indicate that the landfilled waste is mainly municipal waste, not containing these components (Naveen et al, 2017). Also in other studies, the authors reported low concentrations of heavy metals in leachates, emphasizing that their presence is not a major concern at present (Öman and Junestedt, 2008;Bożym et al, 2020). The clearly higher concentrations of chromium in the leachate (except for the landfill in Jawor) could have been caused (as in the case of chromium) by high precipitation in September 2019.…”

Changes of a Landfill Leachate Toxicity as a Result of Treatment With Phragmites australis and Ceratophyllum demersum–A Case Study

“…high phytotoxicity: GI < 50%, moderate phytotoxicity: GI 50-80%, no phytotoxicity: GI > 80%, stimulating effect for plants: GI > 100% (Zucconi et al, 1984;Bożym et al, 2020).…”

“…Figure 2 shows the GI values for the leachate from the four landfills, before and after the biological treatment, dosed at different concentrations. The graphs also show the classification of phytotoxicity based on the GI values, where: GI < 50% -medium high phytotoxicity, GI within 50-80% medium moderate phytotoxicity, GI > 80% no phytotoxicity, a GI > 100% -a plant stimulating effect (Zucconi et al, 1984;Bożym et al, 2020).…”

Assessment of Phytotoxicity of Landfilled Waste and Foundry Dust Based on The Direct Test

“…For this reason, the contact of seeds with the substrate reflects the real conditions. However, for GI tests directly on a substrate, root germination and root elongation may be more difficult to evaluate because the roots may penetrate the substrate, and consequently, a visual assessment may be more complicated (Bożym et al 2021 ). Selecting an appropriate species for the type of toxin and waste may be problematic because each of the species may be characterised by a different tolerance to contamination (Manas and De las Heras 2018 ).…”