33 research outputs found
Response Surface Methodology Optimization in Asphalt Mixtures: A Review
The application of statistical modeling and optimization approaches such as response surface methodology (RSM) is important for the excellent potential to tackle different constraints and goals and the analysis of the relationships between independent factors influencing a particular response. This chapter provides a simple yet detailed literature review on the utilization of RSM for the design of experiments, modeling, and optimization of virgin and alternative materials into asphalt binder and mixtures for sustainability. Meanwhile, an in-depth analysis based on the literature reviewed in terms of asphalt binder modification employing RSM with various independent parameters were summarized. Also, a critical review of the application of RSM to optimize the engineering and mechanical performance characteristics of asphalt concrete mixtures is presented in this chapter. The current chapter concluded that the use of RSM statistical analysis in a highway materials perspective provides a broader understanding of the factors that control pavement performance throughout the pavement service life
Engineering Properties of Palm Oil Clinker Fine-Modified Asphaltic Concrete Mixtures
Palm oil clinker (POC) is a non-biodegradable palm mill by-product typically discarded in dumpsites. This study analyzed the performance of POC powder (POCF) as bitumen modifier in terms of conventional and engineering properties of bitumen and asphalt mixture. For the study, base bitumen of 60/70 penetration grade was utilized and different POCF dosages (0, 2, 4, 6, and 8% by weight of bitumen) were added. The base bitumen was effectively modified with POCF and then characterized. The conventional and engineering properties of the modified bitumen and asphalt mixtures were assessed. From the characterization results, the formation of Si-O crystalline structure and a new Si-OH functional group was identified. Furthermore, a meandering pattern was observed due to the modification of the base bitumen with POCF. Based on the conventional test results it was revealed that the addition of POCF to the base bitumen resulted in a stiffer blend compared to unmodified bitumen. The addition of POCF improved the modified mixtures’ Marshall stability relative to the unmodified mixtures. Analysis of variance (ANOVA) and regression modeling showed the influence and significance of POCF-MB, with R2 values of (95-99%). Finally, the 4-6% POCF dosage was found to be the optimum dosage, yielding the best performance in terms of the engineering properties evaluated
Engineering Properties of Palm Oil Clinker Fine-Modified Asphaltic Concrete Mixtures
Palm oil clinker (POC) is a non-biodegradable palm mill by-product typically discarded in dumpsites. This study analyzed the performance of POC powder (POCF) as bitumen modifier in terms of conventional and engineering properties of bitumen and asphalt mixture. For the study, base bitumen of 60/70 penetration grade was utilized and different POCF dosages (0, 2, 4, 6, and 8% by weight of bitumen) were added. The base bitumen was effectively modified with POCF and then characterized. The conventional and engineering properties of the modified bitumen and asphalt mixtures were assessed. From the characterization results, the formation of Si-O crystalline structure and a new Si-OH functional group was identified. Furthermore, a meandering pattern was observed due to the modification of the base bitumen with POCF. Based on the conventional test results it was revealed that the addition of POCF to the base bitumen resulted in a stiffer blend compared to unmodified bitumen. The addition of POCF improved the modified mixtures’ Marshall stability relative to the unmodified mixtures. Analysis of variance (ANOVA) and regression modeling showed the influence and significance of POCF-MB, with R2 values of (95-99%). Finally, the 4-6% POCF dosage was found to be the optimum dosage, yielding the best performance in terms of the engineering properties evaluated
The Effectiveness of Utilising the Building Information Modelling Based Tools for Safety Training and Job Hazard Ä°dentification
The fields of architecture, engineering and construction (AEC) have kept pace with recent technological developments in design and construction. However, it is difficult to obtain information on the breadth of applications of BIM -based tools throughout the life cycle of construction projects. Hence, this study attempts to empirically identify and evaluate the applications of pre-construction tools, with a focus on safety training and workplace hazard recognition. A questionnaire in the form of a survey was used to collect data. The results show that the ten predictors account for 52.3% of the variation in BIM knowledge (F (10, 56) = 6.133, p < 0.001). It is also found that site analysis and safety instructions have no effect on the measured variable. The study represented a comprehensive blend of research to improve the use of BIM -based tools for safety training and workplace hazard identification. It also contributed to the knowledge of how to use BIM -based tools in the pre-construction phase. The development of the BIM -process flow framework for safety training and hazard identification will be the main focus of future work
Combined treatment of domestic and pulp and paper industry wastewater in a rice straw embedded activated sludge bioreactor to achieve sustainable development goals
The pulp and paper industry has been recognized as one of the largest users of water worldwide. Water is used in nearly every step of the manufacturing process. It generates significant amounts of wastewater and leftover sludge, creating several problems for wastewater treatment, discharge, and sludge disposal. Adopting the most effective and economical treatment techniques before discharging wastewater is therefore crucial. Thus, this study aims to evaluate the performance of the activated sludge bioreactor system (ASBS) for the treatment of pulp and paper industry wastewater (PPIW). The PPIW was characterized. During the experiment, the domestic and PPIW wastewater were run at a fixed HRT of 1 day. Subsequently, the ASBS was evaluated by varying the HRT and OLR. The HRT was varied in the range of 3, 2, and 1 day. At a fixed HRT of 2 days, the maximum and minimum COD removal were 88.4 and 63.2%. Throughout the study, the ASBS demonstrated higher treatment efficiency in terms of COD removal. First order, Grau second order, and modified Stover Kincannon biokinetic models were applied for the study. The biokinetic investigation shows that the modified stover kinetic model was more appropriate for the description of the experimental data in terms of microbial growth parameters. Thus, the kinetic coefficients obtained in this study could be used for the bioreactor scale-up. The study has also proven that the biosorbent made from biomass waste can potentially help preserve non-renewable resources and promote zero-waste attainment and principles of a circular bioeconomy
Agricultural wastewater treatment using oil palm waste activated hydrochar for reuse in plant irrigation : synthesis, characterization, and process optimization
The best possible use of natural resources and the large amounts of trash produced by industrial and human activity is necessary for sustainable development. Due to the threat of global climate change and other environmental challenges, waste management systems are changing, leading to more instances of water resource management. The waste generated must be controlled from a sustainability point of view. Typically, the conventional disposal of Agricultural Wastewater (AW) and biomass can be achieved by recycling, reusing, and converting them into a variety of green products. To improve the AW quality for the purposes of environmental sustainability, Sustainable Development Goals (SDGs) 6 and 14, dealing with clean water, sanitation, and life below water, are very important goals. Therefore, the present investigation evaluates the effectiveness of a Bench-scale Activated Sludge Reactor (BASR) system for AW treatment. The BASR was designed to focus on getting the maximum possible utilization out of a biosorbent derived from oil palm waste activated hydrochar (OPAH). This is in accordance with SDG 9, which targets inorganic and organic waste utilization for added value. An experiment was developed using the Response Surface Methodology (RSM). A Hydraulic Retention Time (HRT) of 1–3 days was used in the bioreactor’s setup and operation, and Mixed Liquor Suspended Solids (MLSS) concentrations of 4000–6000 mg/L were used. BASR was fed with AW with initial mean concentrations of 4486 ± 5.63 mg/L and 6649 ± 3.48 for the five-day Biochemical Oxygen Demand (BOD5) and Chemical Oxygen Demand (COD) experiments, respectively. The results obtained showed that maximum reductions of 84.66% and 72.07% were recorded for BOD5 and COD, respectively. Through RSM optimization, the greatest reductions in the amounts of organic materials were achieved with a 2-day HRT and an MLSS dosage of 5000 mg/L. Substrate elimination thresholds were assessed using the first-order, the Grau second-order, and the modified Stover–Kincannon models. The reported observations were found to be perfectly fit by the modified Stover–Kincannon model, with high R2 values of 0.9908 and 0.9931 for BOD5 and COD, respectively. As a result, the model may be used to design the BASR system and forecast how the reactor would behave. The findings from this study suggest that the developed OPAH has promising potential to be applied as eco-friendly material for the removal of BOD5 and COD from AW. Consequently, the study findings additionally possess the ability to address SDGs 6, 9, and 14, in order to fulfil the United Nations (UN) goals through 2030
Circular economy potential and contributions of petroleum industry sludge utilization to environmental sustainability through engineered processes - a review
The petroleum industry activities unavoidably generate a large quantity of sludge named Petroleum industry sludge (PIS). The generation rate has been increasing because of the ascending energy demand. It is a potential energy resource. PIS has been shown to contain hazardous constituents that may have negative consequences on the environment and public health. Thus, the treatment and disposal of this waste is a global issue. Numerous treatment methods have been demonstrated to reduce sludge volume and toxicity and recover petroleum components. The sludge qualities affect how effective they are. These treatment strategies can reduce the toxic substances in sludge and reduce their detrimental effects on human health and the environment. However, because of the sludge's tenacious character, only a few technologies can meet strict environmental laws while using a sizable amount of water, electricity, and chemicals. PIS treatment methods that are both waste-free and cost-effective are currently unavailable. In terms of environmental engineering significance, this study adopted the systematic review to discuss the waste to resource potential applications of PIS for reusability in sustainable construction, wastewater treatment applications, and gas generation. PIS application ineffective microorganism biofertilizer production, levan production, rubber tires manufacturing, metal catalysts synthesis, carbon–clay composites for use in sensors and electronic devices were also discussed. That is not enough, this review also found that the adoption of the circular economy that represents a new direction to create value and prosperity by elongating product lifespan and moving the waste from the end of the supply chain to the outset is very important. Thus, the circular economy potential of PIS to achieve self-cycle operation through the concept of “wastes-treat-wastes” in the petroleum industry was extensively discussed
Palm Oil Clinker as a Waste by-Product: Utilization and Circular Economy Potential
Conservation of natural resources to create ecological balance could be significantly improved by substituting them with waste by-products. Palm oil industry operations increases annually, thereby generating huge quantity of waste to be dumped into the landfill. Palm oil clinker (POC) is a solid waste by-product produced in one of the oil palm processing phases. This chapter is designed to highlight the generation, disposal problems, properties and composition of POC. The waste to resource potentials of POC would be greatly discussed in the chapter starting with the application of POC in conventional and geopolymer structural elements such as beams, slabs, columns made of either concrete, mortar or paste for coarse aggregates, sand and cement replacement. Aspects such as performance of POC in wastewater treatment processes, fine aggregate and cement replacement in asphaltic and bituminous mixtures during highway construction, a bio-filler in coatings for steel manufacturing processes and a catalyst during energy generation would also be discussed. Circular economy potentials, risk assessment and leaching behavior during POC utilization would be evaluated. The chapter also discusses the effectiveness of POC in soil stabilization and the effect of POC pretreatment for performance enhancement. Towards an efficient utilization, it is important to carry out technical and economic studies, as well as life cycle assessments, in order to compare all the POC areas of application described in the present review article. POC powder has proven to be pozzolanic with maximum values of 17, 53.7, 0.92, 3.87, 1.46, for CaO, SiO2, SO3, Fe2O3 and Al2O3. Therefore, the present chapter would inspire researchers to find research gaps that will aid the sustainable use of agroindustry wastes. The fundamental knowledge contained in the chapter could also serve as a wake-up call for researchers that will motivate them to explore the high potential of utilizing POC for greater environmental benefits associated with less cost when compared with conventional materials
Synthesis, characterization, and performance evaluation of hybrid waste sludge biochar for cod and color removal from agro-industrial effluent
Agro-waste management processes are evolving through the development of novel experimental approaches to understand the mechanisms in reducing their pollution levels efficiently and economically from industrial effluents. Agro-industrial effluent (AIE) from biorefineries that contain high concentrations of COD and color are discharged into the ecosystem. Thus, the AIE from these biorefineries requires treatment prior to discharge. Therefore, the effectiveness of a continuous flow bioreactor system (CFBS) in the treatment of AIE using hybrid waste sludge biochar (HWSB) was investigated. The use of a bioreactor with hydraulic retention time (HRT) of 1–3 days and AIE concentrations of 10–50% was used in experiments based on a statistical design. AIE concentration and HRT were optimized using response surface methodology (RSM) as the process variables. The performance of CFBS was analyzed in terms of COD and color removal. Findings indicated 76.52% and 66.97% reduction in COD and color, respectively. During biokinetic studies, the modified Stover models were found to be perfectly suited for the observed measurements with R2 values 0.9741 attained for COD. Maximum contaminants elimination was attained at 30% AIE and 2-day HRT. Thus, this study proves that the HWSB made from biomass waste can potentially help preserve nonrenewable resources and promote zero-waste attainment and principles of circular economy