Thesis

Biochar for assisted phytomanagement of contaminated soils : short term effects on contaminant availability and plant growth

Creator
Awarding institution
  • University of Strathclyde
Date of award
  • 2014
Thesis identifier
  • T13797
Qualification Level
Qualification Name
Department, School or Faculty
Abstract
  • There has been much interest in using biochar as a low cost sorbent amendment to reduce the risk posed by contaminated sites but an understanding of biochar interactions with plants in a contaminated soil context is still in its early stages. This thesis is based on the overall hypothesis that biochar amendment would improve soil health and plant growth in addition to reducing the availability of organic and inorganic contaminants.Biochars from three different feedstocks (maize stover, olive tree pruning and pine woodchip) and coal-derived activated carbon were used in experimental studies designed to test the thesis hypothesis. Soils contaminated with copper and arsenic (Chapters 2 and 4), mercury (Chapter 3), and polycyclic aromatic hydrocarbons (Chapters 4 and 5) were used in experiments designed to investigate the different effects biochar amendment had on specific contaminant behaviour and mobility in soils.Innovative passive sampling techniques were used to monitor changes in freely dissolved concentrations of the contaminants studied. Rhizon samplers extracted porewater from soil for selected inorganic contaminant analysis while polyoxymethylene (POM) samplers were used in laboratory equilibrium tests to determine freely dissolved concentrations of organic contaminants in soil.Biochars consistently reduced plant uptake (in plant species maize and Italian ryegrass) for both organic and inorganic contaminants. Biochars had a generally beneficial effect on plant growth. Freely dissolved concentrations were reduced for inorganic contaminants copper and arsenic (with the exception of arsenic with olive tree pruning in Chapter 2). Limited to no effects on porewater concentrations were observed for mercury (Chapter 3) and organic contaminants. Activated carbon was more effective at removing organic contaminants from porewater than biochar.By defining the conditions in which sorbent amended soils successfully reduced contaminant bioavailability and improved plant growth, this thesis demonstrates how biochar may prove a valuable tool in the phytomanagement of contaminated soils.
Resource Type
Note
  • This thesis was previously held under moratorium from 29th August 2014 until 29th August 2016.
DOI
Date Created
  • 2014
Former identifier
  • 9910369233402996

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