Bioremediation of cadmium contaminated soil by tea waste and impact on the accumulation of Cd in Helianthus annuus

The work aimed to assess the restoration of metal-contaminated soil pH and EC and impacts on Cd accumulation in plants Helianthus annuus (Sunflower) through tea waste in a natural environment. Various doses of Cd metal treatment (1–5 ppm) were provided to the soil with two sets of organic matter (tea waste) in a dry and wet state. The soil and plants were analyzed using analytical procedures like AAS, SEM and EDS, while pH and EC were measured through pH and conductivity meter. The mitigating effect of tea waste was observed on the pH (6.2–6.9) and EC of the soil, which was reflected by the healthy growth of the plants. It was established that the movement of the Cd was successfully controlled with the restoration of essential nutrient elements in different parts of plants. It was strongly related to recovered soil pH and EC in two sets of tested H. annuus plant species. The healthy growth of the plants showed that tea waste acts as a safe, harmless and sound remediator of soil, which enhances the soil nutrient ionic activity from soil to roots of the plants in the presence of the Cd metal, effective for the use of agriculture purposes.