Effect of dosage and particle size of natural zeolite on the survival of Escherichia coli in soil

Journal of Water and Environmental Nanotechnology

ARTICLE

Safari Sinegani, Ali Akbar¹  Noroozi, Omid¹ 

[1] Department of Soil Science, College of Agriculture, Bu-Ali Sina University

关键词: Escherichia coli;    Nanozeolite;    Zeolite;    Weibull survival model;   

DOI  :  10.22090/jwent.2019.04.004

学科分类：数学（综合）

来源: Iranian Environmental Mutagen Society

【 摘 要 】

Survival of enteropathogenic bacteria in soil is a key factor to control waterborne diseases. In this study, we evaluated the significance of zeolite nanoparticles (nano zeolite) in comparison with natural size particles on the survival of Escherichia coli in the soil incubated in sterile and unsterile conditions to examine the effectiveness of nanosizing on the behavior of natural amendments in the environment. The experimental mixtures prepared by adding zeolite and nano zeolite at levels of 0, 5, 15% w/w to various amounts of a loam textural soil that. Then every mixture inoculated by a nalidixic acid resistance Escherichia coli (E.coli NAR) at a rate of 106 cells per gr soil. Results showed that in the unsterile soils, adding 5% zeolite had no significant effect on survival of bacteria in soil and 15% nano zeolite reduced bacteria survival in soil especially at initial days of inoculation (about 3 log-unit). While adding 15% zeolite and 5% nano zeolite had a significantly positive effect on bacteria’s time need to reach the detection limit (td). Sterilization of soil mixtures significantly enhanced bacteria survival in all treatments. The highest value of td obtained in sterile soil amended with 15% zeolite (46 days). In sterile mixtures adding nano zeolite caused an increasing in bacteria population at initial days after inoculation (about 1-1.5 log-units). Decreasing in the size of natural zeolite particles to nano scale had a negative effect on survival of the studied bacterium in unsterile mixtures and E.coli NAR survived more in zeolite amended mixtures. While this negative effect was not observed in sterile soil. These results clearly showed that the negative biological interaction is the main factor that controls enteropathogenic bacteria’s survival in soil.

【 授权许可】

CC BY