Sonochemical remediation of Mercury from contaminated sediments

Sonochemical remediation of Mercury from contaminated sediments

Bibliographic Details
Main Author: He, Ziqi
Language:English
Published: The Ohio State University / OhioLINK 2006
Subjects:
sonochemistry
ultrasound
mercury
sediment
remediation
desorption
biomass
humic acid
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=osu1155666284
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spelling ndltd-OhioLink-oai-etd.ohiolink.edu-osu11556662842021-08-03T05:51:19Z Sonochemical remediation of Mercury from contaminated sediments He, Ziqi sonochemistry ultrasound mercury sediment remediation desorption biomass humic acid <p>In this study, the development of sonochemistry as an alternative remediation technology of Hg contaminated sediments was investigated. Experiments were conducted in model (Al <sub>2</sub>O <sub>3</sub>and HgS) and field-contaminated sediments (certified PACS-2 marine sediments from NRC) to fundamentally and mechanistically understand how ultrasound will work with Hg and metal contaminated sediments. Ultrasound was able to enhance Hg release from model and real sediments. In the Al <sub>2</sub>O <sub>3</sub>system doped with Hg(II), ultrasound accelerated initial Hg(II) release at pH 4.0 compared to hydrodynamic mixing. With cinnabar (HgS), ultrasonic release of Hg from HgS occurred through oxidizing S into sulfur oxidation products (S <sub>ox</sub>) including S <sub>2</sub>O <sub>3</sub> <sup>2-</sup>, SO <sub>3</sub> <sup>2-</sup>and SO <sub>4</sub> <sup>2-</sup>. Ultrasonic acceleration of Hg release from PACS-2 marine sediments compared to mechanical shaking was also observed.</p> <p>Experimental factors including sonication power intensity and reaction time were observed to affect Hg desorption. The higher the power intensity of sonication, the higher the desorption of Hg(II). Although ultrasound enhanced initial Hg desorption, decreases in Hg desorption occurred with prolonged sonication due to ultrasonic changes to sediment particles. For example, ultrasound dramatically reduced Al <sub>2</sub>O <sub>3</sub>particle size, changed surface morphology and decreased the point of zero charge (PZC). Hg(II) occlusion by aluminum hydroxide re-precipitates was proposed as the primary reason for Hg(II) resorption with longer sonication times. Through the comparison of a series of metals of Hg(II), Pb(II), Ni(II) and Cr(III), the net ultrasonic desorption of metals from Al <sub>2</sub>O <sub>3</sub>was related to metal binding strength, ultrasonic conditions and metal water exchange rates. Besides ultrasonic factors, the effects of sediment matrix parameters including pH, chloride, and organic matter were examined.</p> <p>A transgenic C. reinhardtii (2AMT-2) expressing a plasmamembrane-anchored metallothionein polymer was tested to quickly uptake Hg(II) from aqueous phase due to its higher binding capacity and broader pH range than wild type alga. The combined technique of ultrasound and 2AMT-2 was effective to remove Hg from solids and sediments, especially from Al <sub>2</sub>O <sub>3</sub>and HgS with no natural organic matter.</p> 2006-09-20 English text The Ohio State University / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=osu1155666284 http://rave.ohiolink.edu/etdc/view?acc_num=osu1155666284 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic sonochemistry
ultrasound
mercury
sediment
remediation
desorption
biomass
humic acid
spellingShingle sonochemistry
ultrasound
mercury
sediment
remediation
desorption
biomass
humic acid
He, Ziqi
Sonochemical remediation of Mercury from contaminated sediments
author He, Ziqi
author_facet He, Ziqi
author_sort He, Ziqi
title Sonochemical remediation of Mercury from contaminated sediments
title_short Sonochemical remediation of Mercury from contaminated sediments
title_full Sonochemical remediation of Mercury from contaminated sediments
title_fullStr Sonochemical remediation of Mercury from contaminated sediments
title_full_unstemmed Sonochemical remediation of Mercury from contaminated sediments
title_sort sonochemical remediation of mercury from contaminated sediments
publisher The Ohio State University / OhioLINK
publishDate 2006
url http://rave.ohiolink.edu/etdc/view?acc_num=osu1155666284
work_keys_str_mv AT heziqi sonochemicalremediationofmercuryfromcontaminatedsediments
_version_ 1719426645349105664

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