A factorial experimental analysis of using wood fly ash as an alkaline activator along with coal fly ash for production of geopolymer-cementitious hybrids.

Alkaline activated materials such as geopolymers and cementitious materials derived from pozzolanic reactions offer several advantages over the currently widely used Portland cement, especially in terms of environmental sustainability and physiochemical properties. However due to the need of an alkaline activator, such as NaOH or KOH, which result in high production cost and requires skilled personnel, they have not been deeply explored and put to use. Here in this study, wood fly ash, a by product of wood combustion is used as an alternative source of alkaline activator for producing such alkaline activated materials along with coal fly ash, where the resulting geopolymer-cementitious hybrid (GCH) was characterized physico-chemically through electron microscopy, BET, FTIR, XRF & XRD.

Evaluation of sewage sludge incineration ash as a potential land reclamation material.

This study evaluated the potential of utilising sewage sludge incineration ash as a land reclamation material. Toxicity assessment of the leachate of the ash was carried out for both terrestrial and marine organisms. Both the fruit fly Drosophila melanogaster and barnacle Amphibalanus amphitrite showed that both bottom and fly ash leached at liquid-to-solid (L/S) ratio 5 did not substantially affect viabilities.

Effective Recovery of Vanadium from Oil Refinery Waste into Vanadium-Based Metal-Organic Frameworks.

Carbon black waste, an oil refinery waste, contains a high concentration of vanadium(V) leftover from the processing of crude oil. For the sake of environmental sustainability, it is therefore of interest to recover the vanadium as useful products instead of disposing of it. In this work, V was recovered in the form of vanadium-based metal-organic frameworks (V-MOFs) via a novel pathway by using the leaching solution of carbon black waste instead of commercially available vanadium chemicals.

Evaluation of the leaching behavior of incineration bottom ash using seawater: A comparison with standard leaching tests.

Batch and column tests were conducted on untreated incineration bottom ash (IBA) samples from two incineration plants in Singapore, using seawater as the leachant. The main objective of this study was to investigate the change in the leaching behavior of certain elements (i.e.

Influence of moisture content and temperature on degree of carbonation and the effect on Cu and Cr leaching from incineration bottom ash.

This study investigated the influence of moisture content and temperature on the degree of carbonation of municipal solid waste (MSW) incineration bottom ash (IBA) from two different incineration plants in Singapore. The initial rate of carbonation was affected by the nominal moisture content used. Carbonation temperature seemed to play a part in changing the actual moisture content of IBA during carbonation, which in turn affected the degree of carbonation.

Accelerated carbonation of different size fractions of MSW IBA and the effect on leaching.

Accelerated carbonation has been studied as a treatment method for MSW IBA, and the main advantage is that it can shorten the treatment duration from months to days, compared to natural weathering. This study investigated the effect of accelerated carbonation on different size fractions of IBA collected from two incineration plants in Singapore. The different size fractions were ground to <425μm to minimise the influence of morphological difference on carbonation efficiency from that of chemical and mineralogical differences.