Author: Liang, Chaofu
Title: Mitigation of copper phytotoxicity to maize and cucumber by TiO₂ nanoparticles
Advisors: Li, X. D. (CEE)
Degree: M.Sc.
Year: 2018
Subject: Hong Kong Polytechnic University -- Dissertations
Phytoremediation
Nanoparticles -- Environmental aspects
Plants -- Effect of heavy metals on
Heavy metals -- Environmental aspects
Department: Faculty of Construction and Environment
Pages: 57 pages : color illustrations
Language: English
Abstract: Severe heavy metal pollutants are widely present in soil around the world, and may pose risk on food safety and consequently human health. Simultaneously, continuous high production of engineered nanoparticles (NPs) has contributed to their large accumulation in agricultural soils. Therefore, it is important to reveal how nanoparticles may influence the geochemical fate and food chain of heavy metals in contaminated site, and may bring deep understanding on heavy metal remediation technologies. In this study, we selected copper, an essential micronutrient for plant, to investigate its interaction with TiO₂ nanoparticles during maize and cucumber vegetation in hydroponic system. After 10-day hydroponic culture, plant seedlings were transferred into 50 ml plastic centrifuge tubes for different treatments with free copper with or without TiO₂ nanoparticles for two days. In the study, the seeding growth, TOC content, chlorophyll content, and copper and titanium content in plant tissues were measured. Furthermore, the copper species in shoot and root were analyzed using XANES technique. The results showed that TiO₂ NPs can mitigate the poisoning effect of copper on plant seedling significantly evidenced by the plant mass content. In addition, copper stress induced sharp increase in TOC content of hydroponic solution. Titanium was only detected in root, with no detection in shoot tissue, which indicated no or very less TiO₂ nanoparticles assimilated into plant seedlings in such a short term. TiO₂ nanoparticles significantly decreased the content of copper in both root and shoot, e.g., 60% and 20% decline of copper content in maize shoot and cucumber shoot, respectively, coexisting with 250NPs + 16 mg/L Cu. Copper XANES analysis indicated a large amount of adsorbed copper species on TiO₂ nanoparticle in plant root samples, which consequently decreased the mobility of copper and alleviated its toxicity to plant. This results provide better proof for the mitigation mechanism of copper under NPs coexistence. Further study in a longer culture period of plants should be conducted.
Rights: All rights reserved
Access: restricted access

Files in This Item:
File Description SizeFormat 
991022244146003411.pdfFor All Users (off-campus access for PolyU Staff & Students only)2.92 MBAdobe PDFView/Open


Copyright Undertaking

As a bona fide Library user, I declare that:

  1. I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
  2. I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
  3. I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.

By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.

Show full item record

Please use this identifier to cite or link to this item: https://theses.lib.polyu.edu.hk/handle/200/10056