Application of nano iron in the remediation of Cr-contaminated soil and its effect on plant growth and soil bacteria

Other Title(s)

استخدام النانو حديد في تنظيف التربة الملوثة بعنصر الكروميوم و تأثير ذلك على نمو النبات و بكتيريا التربة

Dissertant

Zaydani, Shirin Tariq

Thesis advisor

Shahwan, Talal

Comitee Members

Awad, Hani
Harb, Jamil

University

Birzeit University

Faculty

Faculty of Science

Department

Department of Chemistry

University Country

Palestine (West Bank)

Degree

Master

Degree Date

2015

English Abstract

Recently, a huge amount of laboratory-scale research and field tests are being carried out internationally in order to assess the effectiveness of iron nanotechnology in environmental cleanup.

Published results have shown that nano iron is an effective tool for remediation of water and soil from various kinds of organic and inorganic pollutants.

Together with this, increasing attention is also paid to the impact of nano iron on the biosphere.

In this study, nano iron was applied to remediate soil samples contaminated with chromium.

Hexavalent chromium is a well known pollutant in water and soil, particularly in the vicinity of industrial regions.

In addition to this, the effect of nano iron on plant growth and soil bacteria was investigated.

This research was conducted in cooperation between Chemistry department and department of Biology and Biochemistry at Birzeit University.

Nano iron was synthesized, and its efficiency toward Cr(VI) removal was tested using laboratory scale experiments under various experimental conditions.

The assessment of nano iron impact on plant growth and soil bacteria was realized using the facilities found at the department of Biology and Biochemistry.

The results indicate that both of nZVI and Z-nZVI materials are very effective in Cr(VI) removal, as the percentage removal exceeded 90 percent for most of the studied concentrations.

For nZVI, equilibrium of Cr(VI) removal is approached in about one hour of contact between liquid and solid phases.

For Z-nZVI, the process was slower and more than four hours were required to attain equilibrium.

The data of Z-nZVI obeyed pseudo first order kinetics, with k1 (rate constant) calculated as min-1, and Qmax (maximum sorbable amount) found as mg/g.

The removal of Cr(VI) is high over a wide range of pH values, the removal was seen to decrease in the alkaline medium.

Generally, the removal of Cr(VI) by Z-nZVI is more pH-dependent than that of nZVI.

The results of EDX mapping analysis showed that the Cr signals are associated with the Fe signals, not with Si, indicating that Cr ions favors binding to iron nanoparticles more than soil.

No negative effect of nZVI and GT-Fe on Corn growth at the lower applied dose (0.1 mg/Kg) on soil fertility and plant nutrition was observed, however, high concentrations of Fe NPs can be harmful to the corn plants.

The results of bacteria tests showed that Cr(VI) solutions have little effect on the tested bacteria types at low concentrations, but detrimental effects at higher concentrations.

nZVI (and Cr-nZVI) demonstrated the highest detrimental effect, GT-Fe NPs had less detrimental effect than nZVI.

The extent of the effect will depend significantly on the applied concentration.

Main Subjects

Chemistry

No. of Pages

133

Table of Contents

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Language

English

Data Type

Arab Theses

Record ID

BIM-728298