ABSTRACT
The work presented in this paper was carried out to statistically evaluate and quantify the material-source effect on the asphalt-binder's rheological properties using Analysis of Variance (ANOVA) and Tukey's Honestly Significant Difference (Tukey´s HSD) test. The study focused on the Asphalt-Binders' high-temperature rheological properties, namely, the G*, δ, G*/Sin(δ) and G*/(1 - (1/Tan(δ)Sin(δ))) parameters, measured using the Dynamic Shear Rheometer (DSR) device. The DSR data analyzed in the study were extracted from the Texas flexible pavements and overlays database, namely, the Texas Data Storage System (DSS), covering two Asphalt-Binders (ABs), performance grade (PG) 64-22 and PG 76-22 plant-mix extracted ABs that were treated as rolling thin film oven (RTFO) residue, and sourced from 14 different suppliers. The study findings substantiate that material-source has an effect on the high-temperature rheological properties of ABs. Additionally, it was also concluded that in as much as performance superiority and costs are crucial issues in deciding the AB source/provider, consistency and quality aspects cannot be disregarded. Therefore, material-source effects should be inclusively evaluated from both performance (rheological properties) and quality (consistence) standpoints as well as cost considerations when choosing a supplier. In general, the study contributes to the state-of-the-art enrichment on aspects of material-source effects on RTFO residue ABs' high-temperature rheological properties, consistency, variability, and data quality.
ABSTRACT
The volume of industrial and domestic wastewater is increasing significantly year by year with the change in the lifestyle based on mass consumption and mass disposal brought about by the dramatic development of economies and industries. Therefore, effective advanced wastewater treatment is required because wastewater contains a variety of constituents such as particles, organic materials, and emulsion depending on the resource. However, residual chemicals that remain during the treatment of wastewaters form a variety of known and unknown by-products through reactions between the chemicals and some pollutants. Chronic exposure to these by-products or residual chemicals through the ingestion of drinking water, inhalation and dermal contact during regular indoor activities (e.g., showering, bathing, cooking) may pose cancer and non-cancer risks to human health. For example, residual aluminium salts in treated water may cause Alzheimer's disease (AD). As for carbon nanotubes (CNTs), despite their potential impacts on human health and the environment having been receiving more and more attention in the recent past, existing information on the toxicity of CNTs in drinking water is limited with many open questions. Furthermore, though general topics on the human health impacts of traditional water treatment chemicals have been studied, no comparative analysis has been done. Therefore, a qualitative comparison of the human health effects of both residual CNTs and traditional water treatment chemicals is given in this paper. In addition, it is also important to cover and compare the human health effects of CNTs to those of traditional water treatment chemicals together in one review because they are both used for water treatment and purification.