Synthesis and characterisation of silica adsorption platforms for use in environmental remediation

In this work a new method of production of MCM-41 was used which involved synthesis under mild conditions (room temperature) and shorter reaction times as well as reduced surfactant removal times (15 min) compared to the previously published methods that take approximately 10 h. This material was functionalised with an amine-based functional group to study the feasibility of separation of chromium (III) and chromium (VI) from aqueous solution. A maximum adsorption capacity calculated using Langmuir isotherms of 111.1 mg g-1 was achieved, which was higher than previously reported for competitive sorbents. Moreover, adsorbents containing silica nanoparticles with different porosity parameters were synthesized and evaluated for Cr (VI) uptake. The adsorption mechanism was defined by a two step adsorption mechanism for AP-MCM-41 while other sorbent exhibited a fast one step adsorption mechanism. The regeneration of MP-MCM-41 loaded with Hg (II) ions was also investigated with batch and dynamic methods using thiourea that was acidified using HNO3, H2SO4, or HCl; with HCl being the most efficient with recovery efficiency of over 90 %.A simple, rapid, bio-inspired green silica material was then developed producing a silica material with iron nanoparticles being incorporated into the framework (Fe-GN). The efficiency of Fe-GN material for the removal of arsenic ions from contaminated solution was evaluated. The material was found to be effective for the removal of arsenate ions with a maximum adsorption capacity of 69 mg/g of Fe-GN. Moreover, a method was developed to regenerate the Fe-GN allowing for full recovery and reuse of the adsorbent in subsequent extractions. Finally, the Fe-GNs material, along with other conventionally available materials, was assessed for the removal of naphthalene from aqueous solutions. The Fe-GN material was found to only have a slight affinity for the adsorption of naphthalene.

Name dc:type.qualificationname

phd

Level dc:type.qualificationlevel

doctoral-pg

Grantor dc:publisher.institution

University of Strathclyde

Year dc:date.issued

2014

Author dc:creator

• Alotaibi, Khalid Mohammed

DOI

10.48730/jdvb-cd09

Identifier

T13970

OAI identifier oai:identifier

oai:strathclyde:jm214p12r