Chemistry Scholarships

Lignite for waste water remediation

This project will investigate the use of the use of run-of-mine (ROM) lignite and chemically modified lignites for the adsorption of high colour contaminants from industrial wastewater streams, particularly those derived from pulp and paper mills..

Background: Local paper manufacturers, together with water authorities are interested in developing economic approaches to the removal of highly coloured contaminants in waste water streams that result from wood pulping processes.  Such contaminants cause fouling on filtration and reverse osmosis membranes and are, thus, a significant obstacle to increased recycling of industrial wastewater.

Cumulative adsorption of Dissolved Organic
Carbon by various lignite samples

Prior work1-2 at Monash University demonstrated the ability of ROM lignite to adsorb significant quantities of organic contaminants found in the wastewater expressed from thermally-dewatered lignite.  It is envisaged that a similar approach can be applied treat wastewater produced by local paper mills.
The research program will involve the characterisation of wastewater provided by local companies Gippsland Water (GW) and KCA. The purification of these waters using a variety of adsorbents will then be investigated:  activated carbon will be used as a model adsorbent, which will be compared with various ROM lignites and chemically modified lignites.  Amongst the key parameters to be determined will be the loading capacity of the adsorbents together with aspects of the chemical and physical structure which control this capacity.  The viability of desorption (regeneration) will also be investigated.  The solid product, which is lignite with adsorbed organic contaminants, will have a positive net energy value and so it could be used as a combustion fuel, or possibly, as a useful fertiliser. In later stages of the project it is envisaged that a process model based on the laboratory data can be developed and an industry scale test pursued (in collaboration with industry partners).
The project will be carried out jointly across the School of Chemistry and the Dept Chemical Engineering (Australian Pulp and Paper Institute).

Funding: This project is supported by a research grant from the Energy Technology Innovations Scheme (ETIS) of the Victorian state government.

References:
CJ Butler, AM Green and AL Chaffee – Remediation of Mechanical Thermal Expression product waters using raw Latrobe Valley brown coals as adsorbents. Fuel, 86, 1130–1138 (2007).
2 CJ Butler, AM Green, AL Chaffee, Remediation of Mechanical Thermal Expression product waters using raw Latrobe Valley brown coals as adsorbents, Fuel, in press, corrected proof available on-line (2007)