The effect of the incorporation of treated waste pressed palm oil fruit fibre (PPOFF) as additives on the mechanical properties of sandcrete masonry blocks (SMBs) was investigated in this study. Taguchi-grey relational analysis (T-GRA) optimization technique was employed to optimize the applied process parameters that involved treated PPOFF, water to cement (W/C) ratio and mould volume (MV). The percentages of PPOFF added were 0.00%, 0.25 %, 0.50 %, 0.75 % and 1.00 % of the cement mass. The treated PPOFF was assigned four levels, while W/C ratio and MV were assigned two levels each in the L8 (4^1x2^2) Taguchi mixed level orthogonal array chosen for the design of experiment. The results obtained with the T-GRA optimization technique showed that the peak response values of the evaluated properties of the produced SMBs, which included compressive strength (CS), bulk density (BD) and water absorption capacity (WAC), were 4.58 N/mm2, 2066 kg/m3 and 4.12 % respectively. The optimal parameter level combination that gave the peak response values in the evaluated properties was found at A1B2C1. This represents 0.25 % treated PPOFF, 0.65 W/C ratio and 0.0101 m3 MV. These values indicate that the produced SMBs are of high quality and can be used as load bearing walls in building industries. The scanning electron microscope images of the produced SMB samples revealed that there was tight PPOFF-cement matrix bonding quality. These imply that the inclusion of the treated PPOFF in the production of SMBs greatly improved its properties. Lastly, the predictive models developed and assessed statistically for the evaluated properties were found to be good and reliable for predicting the properties of such blocks within the range of data considered in this study.

Previous studies show promising effects of some standard fly ash classes on asphalt. However, there is limited research into off-spec fly ash. Multiple studies published presented fly ash as unique compared to traditional mineral fillers. In this paper, several coal combustion wastes (CCW) are examined in terms of their physio-chemical interaction with asphalt binders. Eight types of CCW are blended with two types of asphalt binders: unmodified and polymer modified (PMA). The physical properties and chemical composition of the CCW are characterized. Testing is focused on identifying changes in binder performance after blending with the CCW to understand the role of the CCW. The experimental program is focused on damage healing, rheological performance, and Low-temperature cracking potential. All the blends are conditioned using the pressure aging vessel. Oxidative aging is quantified through measurement of both carbonyl (ICO) and sulfoxide (ISO) indices by Fourier-Transform Infrared Spectroscopy (FTIR). Results show that some of the CCWs are associated with improved rheological performance, damage healing, and cracking resistance. The improvement is attributed to the level of interaction between the binder and the CCW and the physical and chemical characteristics of the CCW. Testing results demonstrate that synergy between the CCW particles and polymer modifiers needs further investigation. Statistical regression analysis is used to quantify the level of significance of influencing factors on the blend performance. The analysis revealed that the level of interaction between the CCW and the binder is measurable by the phase angle of the blend. The CCW’s silicon (Si), Sulfur (S) content, along with particle size distribution and specific gravity, are the significant chemical and physical properties influencing the blend performance. These findings propose a fruitful upcycling opportunity for some CCW as an enhancer of asphalt performance.

With the rapid population growth, the annual plastic waste generation is increasing. There is a dire need for reusing plastic waste. If plastic waste is not recycled it ends up in landfills; ocean garbage patches or is incinerated; which causes different environmental problems, and if pollution from incineration plants is controlled then the plant becomes so expensive that not all countries can afford it. The addition of plastic waste to the flexible pavement has become an attractive option because this improves flexible pavement performance and eliminates the environmental problem. Huge work is done on waste addition in the bituminous mix but this review paper focuses on research done on utilizing plastic wastes as a modifier in a bituminous mix of flexible pavement.

There is a rise of interest in various aspects of biochar derived from waste biomass to address the most pressing ecosystem challenges. This study contributes to understanding biochar's usage in the remediation of hazardous pollutants. The synthesis of biochar using a variety of different techniques has been explored. Numerous analysts have considered biochar as a strategy for enhancing their ability to remediate pollutants. Process factors are primarily responsible for determining biochar yield. Biochar-derived biomass is an exceptionally rich wellspring of carbon produced from biomass utilizing thermal combustion. Activating biochar is another field where biochar is increasingly used to remove specific contaminants. Closed-loop methods to produce biochar expand options. Distributed biochar manufacturing processes are an efficient method to develop businesses, manage waste, and increase resource proficiency in environmental applications. Additionally, this research discusses knowledge gaps and future directions in toxic pollutant remediation through biochar.