Keith Kim Hung Choy

The prediction of sorption from a binary mixture of acidic dyes using single- and mixed-isotherm variants of the ideal adsorbed solute theory

Abstract Equilibrium isotherms have been determined for the adsorption of two single-component and one binary acid dye solutions on carbon. The ideal adsorbed solute theory (IAST) has been used to predict isotherm data for the binary system using the single-component dye sorption data alone. A detailed analysis has been carried out to investigate the effect of different error criteria for determining single-component isotherm parameters and their influence on the results of IAS model simulations using the Langmuir and Freundlich isotherm equations. It was found that the “best-fit” single-component isotherm based on the minimum error criteria did not result in the “best-fit” IAS model predictions. Furthermore, the IAS model producing the closest fit to the binary experimental data did not use the same isotherm model as the single-component data for one dye. Reasons for this apparently anomalous behaviour have been discussed and the most likely cause appears to be dye–dye interactions in the binary system.

Municipal Solid Waste Utilization for Integrated Cement Processing with Waste Minimization: A Pilot Scale Proposal

A novel design of an integrated process for cement production incorporating municipal solid waste (MSW) separation and combustion has been developed. The novel design offers significant opportunities for waste minimization. The MSW combustion system design incorporates the use of supplementary fuel from waste marine oil. Very high temperature, 1200C, high turbulence and high residence time, >4 s, are achieved. This results in very high burnout of MSW, resulting in negligible particulate organic matter to form dioxin by de-novo synthesis. The energy produced is used for the cement process calcination of limestone and residual heat is converted into energy to drive the cement plant. The calcination process itself is used as a large scrubber to remove SO x and HCl, the latter minimizing the chance of dioxin formation further. A front end materials recovery and recycling facility, MRRF, is used to remove valuable recyclable components, chlorine-based plastics and metal-containing materials, such as batteries. The combustion of the MSW achieves a 85–90% volume reduction and the MSW ash is used as a feedstock for the production of the cement clinker.

Synergistic Multilayer Adsorption for Low Concentration Dyestuffs by Biomass

Abstract Due to the high cost of adsorbents and their thermal regeneration in recent years, much research has focused on the search for cheaper adsorbents for treating wastewater from textile industry. The single component adsorption of an acidic dye, Acid Yellow 117, and a basic dye, Methylene Blue, onto several adsorbents—bamboo, waste wood, bamboo char, waste wood char, bamboo activated carbon, wood activated carbon and active carbon F400 were conducted. Based on a Langmuir analysis, the monolayer adsorption capacities were determined. Three of the adsorbents were selected for binary layer adsorption to check the multilayer concept and the potential application for better adsorbent usage. The two cheapest adsorbents, bamboo and wood are compared with the commercial activated carbon F400, and all three systems were successful.