Application of adsorption methods to determine the effect of pH and Cu-stress on the changes in the surface properties of the roots

Abstract

A b s t r a c t. Rye plants were grown in a nutrient solution prepared according to Hoagland for 2 weeks at pH 7, next for 14 days at pH 4.5 (without Cu +2) and in the presence of 20, 50, or 100 mg dm -3 copper ions. The control plants were grown continuously at pH 7. The physicochemical surface properties of the roots were examined using two adsorbates -polar (water vapour) and non-polar (nitrogen). The surface properties of the roots grown at pH 4.5 without Cu +2 were apparently the same as those of controls. The roots of rye which grew in the presence of Cu +2 were characterized by lower (relative to controls) specific surface area values. Statistically significant differences in the size of the apparent surface area (determined by water vapour) were reported for roots incubated with copper ions at a concentration of 20 and 50 mg dm -3 . The average water vapour adsorption energy of the root surface decreased under the stress conditions. There were no statistically significant differences for the free surface area and characteristic energy of nitrogen adsorption.K e y w o r d s: adsorption energy, water vapour/nitrogen, apparent and free surface area, pH, roots, copper INTRODUCTION

Hepatocellular Effect of Copper Poisoning on the Liver and Kidney of Albino Rats (<i>Rattus norvicus</i>)

“…Metal toxicity is a challenging condition affecting the growth and well-being of living organisms globally which is triggered by anthropogenic activities in the environment [1] Copper is one of the prominent metals in which its continuity in the environment has led to toxic effects on many aqueous and terrestrial organisms (including invertebrates, birds, and mammals) due to the application of manure, sewage sludge and cupric pesticides [2,3,4]. Most soils all over the world contain an average of amount of copper ranging between 13 to 30mg/kg d.w. and the exceeding limit is 50mg/kg d.w. [5,6,7]. One of the essential metals required by the body is Copper (Cu) which is expedient for physical and mental health.…”

“…Copper has also been implicated in the inhibition of health, and well-being and adversely affects the growth, health, reproductive performance and life span of all living organisms. Copper has been shown to exhibit some properties; including protective abilities in plants preventing attack by diseases in plants, it also affects nitrogen metabolism and DNA/RNA synthesis [6,9]. At elevated concentrations, copper may become phytotoxic leading to metabolic disorders which could be a potential risk to animal health through the food chain [10].…”

Changes in the size of the apparent surface area and adsorption energy of the rye roots by low pH and the presence of aluminium ions induced

“…Measurement of adsorption -desorption isotherms of water vapour in roots has been performed in accordance with the procedure described in detail in Szatanik-Kloc (2014). The isotherms have been measured in three replicates.…”

“…Because the adsorption on organic material are different than with respect to minerals or soils, instead of the name 'surface area' used name the 'apparent surface area' in the method of adsorption-desorption of water vapour. (Szatanik-Kloc, 2014). The apparent surface area and adsorption energies have been calculated using the experimental adsorptiondesorption data for the p/p0 range between ca.…”