M. Farzadian, S. Hojati, Gh. A. Sayyad , N. Enayatizamir,
Volume 19, Issue 72 (8-2015)
Abstract
One of the major problems associated with petroleum-contaminated soils is water repellency, especially in arid regions of the world. Hence, a variety of methods such as clay addition has been proposed to improve the hydrophobicity of soils. This research was conducted to evaluate the influence of zeolite application on water repellency of an oil-contaminated soil from Khuzestan Province under various treatments including initial soil moisture content (0, 10, 20, and 30 weight %), the amount of applied zeolite (2, 4 and 8 weight %), size (25-53 and <2 μm), and exchangeable cation (Sodium and Calcium). The hydrophobicity of soil sample was determined using Water Drop Penetration Time (WDPT) method. The results showed that by increasing the amount of applied mineral WDPT decreased, where the application of 2 percent of zeolite led to the reduction of WDPT by about 27 percent less than the control. The results also indicated that soils treated with sodium-saturated zeolite had less WDPT than the calcium-treated samples, where the average of WDPT in sodium and calcium treatments decreased by 23% and 5% compared with the control, respectively. The initial moisture content of 30 percent showed the best performance with the decreasing WDPT of about 67 percent. Furthermore, the effect of mineral particle sizes showed a meaningless reduction in WDPT.
E. Sabbagh Tazeh,
Volume 26, Issue 1 (5-2022)
Abstract
The utilization of organic amendments in the reclamation of saline-sodic soils can reduce the necessity for the application of chemical Ca+2 sources. In this research, soil leaching experiments were conducted in CRD as split factorial. The main factors were 1) amendment type including manure and compost, 2) amendment rate including 1, 3, and 5 percentage w/w, and 3) leaching stage with 5 levels including without leaching, once, twice, three times, and four times leaching, every time with one pore volume and with 30 days’ intervals. All columns were incubated for 30 days after the addition of amendments and then were leached. The parameters in each column were studied in three depths as a subplot. After 120 days, EC and ESP of soils amended with both types of conditioners reduced under 5 dS m-1 and 15%, respectively. After 150 days, the exchangeable K and Mg were reduced by both conditioners. Exchangeable Ca increased significantly in both amendments at the end of the 5th month. The efficiency of 1% by weight of two conditioners in improving the salinity and sodicity characteristics of soils was the same as other rates. There was not a significant difference between leaching by 3 and 4 pore volume in both conditioners in the most of parameters. In leaching treatment with three pore volumes using 1 percentage w/w of manure and compost, soil EC decreased by 80% and 71% and soil ESP by 44.5% and 35%, respectively.
