Acid soil amendment by zeolite, sepiolite and diatomite

Abstract

The aim of this research was to reduce the heavy metal movement to the biosystem using clay minerals including zeolite, sepiolite, and diatomite. The clay soil and sandy loam soil were made contaminated with 200, 350, 700, and 250 mg of Zn, Cu, Cr, and Ni per kg of soil, respectively. The ratio of clay minerals added to soils was 2.5%, 5%, and 7.5%. The determination of various forms of heavy metals bound to soil mixed with clay minerals and left for a period of 30 and 60 days was carried out using the sequential extraction method. The results indicated that Ni and Zn were mostly in an exchangeable form, while Cu and Cr were mostly in an oxide bound form and an organically bound form. The pH of the soils increased after adding clay minerals. Diatomite caused the smallest change in the pH value. Chromium had the best adsorption capacity by bonding with various elements in the soil, followed by Cu, Zn, and Ni, respectively. The addition of sepiolite caused more heavy metals in a stable form than adding zeolite and diatomite. When adding clay minerals to both types of soil, the highest impact was on Ni, followed by Zn, Cu, and Cr, respectively. The bioavailable index (BI) value was the least when adding sepiolite. The risk of heavy metals moving to the biosystem was lower when increasing the incubation time. Without adding any clay mineral, the BI value of metals in the sandy clay loam soil was higher than that in the clay soil.

Effect of fly ash amendment on sandy soil properties and peanut yields

“…Soil amendment has been a topic of interest in agriculture using various treatments including addition of inorganic [23] and organic materials from industrial or agricultural wastes [24]. In this study, the amendment of FA alone into sandy soil increased significantly the proportion of silt-sized particles from 6.92% to 16.15% in 10% FA.…”

Adding manure and zeolite to improve soil chemical properties and increase soybean yield

“…Gupta, Aneja, & Rana (2016) noted that cow manure has the ability to increase soil fertility through its organic matter compounds. The combination of manure and zeolite has the greatest positive effect on soil productivity: zeolite increases pH, cation exchange capacity, and soil organic matter (Chaiyaraksa & Tumtong, 2019;Li et al, 2009), and its effects persist despite the decomposition of organic matter contained in manure (Truc & Yoshida, 2011), a process that positively contributes N, P, and K to the soil.…”

Contaminated soil amendment by diatomite: chemical fractions of zinc, lead, copper and cadmium

“…According to Ye et al (2015), diatomite immobilized heavy metals in contaminated acidic soil. Chaiyaraksa and Tumtong (2019) reported the bioavailable index (BI) values of Zn, Cu, Cr and Ni decreased in contaminated acidic soils amendment by adding sepiolite, zeolite and diatomite. Huang et al (2020) represented that modified diatomite can be applied for the immobilization of some metals in polluted soil.…”