The effects of natural zeolite on ions adsorption and reducing solution electrical conductivity II) Cl and NO3 solutions

Abstract

Zeolites can change soil solution compositions due to having high capacity of adsorption as well as water holding capacity. Zeolite are able to decrease fertilizer losses and their leaching from the soil and also able to adsorb the environmental pollutants such as heavy metals and toxic elements from the wastewaters. Some soil solutions are rich of different metals as well as anions which may potentially be harmful for the organisms and the environment. Natural zeolites such as clinoptilolite, analcime, laumomtite, phillipsite, mordenite are crystalline alominosilicate minerals and are effective minerals to decrease the risk of toxic cations as well as anions. In a series of experiments different mixtures of soil with zeolite were prepared using 0, 0.5, 1, 5, 10 and 100 percent of zeolite by weight. The constant amounts of mixtures were treated with constant volumes of solutions containing NaCl, NaNO3, KCl and KNO3. The electrical conductivity of each solution was 0, 5, 10, 15 and 20 dS/m. All samples were replicated two times and each batch of experiment was containing 60 samples with total number of 240 samples for the whole experiment. Mixtures of soil with zeolite were treated with different salt solutions and were shake for two hours prior to analysis. All suspensions were filtered and their electrical conductivity was measured at constant temperature. The results showed that electrical conductivity of filtered solutions was lower in mixtures containing zeolite compared to soil. Also the electrical conductivity of the filtered solutions was considerably lower in NO3 – solutions compared to Cl–. It concluded that zeolite could probably reduce the electrical conductivity of soil solutions by adsorption of ions from the primary solutions and it seems that zeolite would tend to adsorb more NO3 – ions compared to Cl– ions from the solutions resulting lower electrical conductivity of NO3 – containing compared to Cl– containing solutions.