The Establishment Of Setback Distance For Malodour Mitigation From Palm Oil Mill

Malaysia is the largest producer and exporter of palm oil. During the palm oil mill process, it will release an enormous amount of palm oil mill effluent which becomes a major odour problem. There are varieties of methods in managing the malodour such as biofilter, but those methods are expensive and high-maintenance. As the alternative, the setback distance method can be used as this approach is low-cost and effective. This research was carried out to verify the performance of three different setback distance methods: 1) in-field monitoring using Olfactometer, 2) the CALPUFF model and 3) the Gaussian plume model calculation. Since no research has compared the three methods, this study examined the suitability to be used in Malaysia and the effectiveness of the methods. Results show that the proper setback distances were 1.3 km by using in-field monitoring, 1.2 km by using CALPUFF model and 0.5 by using the Gaussian plume model calculation. Research shows that there a huge different in odour concentration value at the surrounding area from those methods with for 385 OU m–3 in-field monitoring, 6.1 OU m–3 for dispersion model and 81 OU m–3 for Gaussian plume model calculation. The differences was cause by the different process in running the method and also the needed data. This research can recommend a proper way to build a setback distance and setback distance value to reduce odour nuisance in th

Latest progress on the influencing factors affecting the formation of TiO2 nanotubes (TNTS) in electrochemical anodization- A minireview

TiO2 nanotubes (TNTs) have drawn special attention for their wide range of applications in a variety of fields. In comparison to other TiO2 nanostructures, it is attracted much due to its high surface area and low fabrication cost. By using the electrochemical anodization approach, highly ordered TNT arrays can be produced with minimum cost compared to other synthesized methods. The nanotubes of the desired diameter, length and wall thickness can be tailored by adjusting anodization parameters. Here in this article, the effects of anodization parameters including type of electrolytes, electrolyte concentration, pH, temperature, aging, anodization voltage, time and type of electrodes on tube formation, tube diameters, length, thickness, organization, and formation mechanisms are reviewed. The collection methods of asproduced TNTs from Ti substrate also summarized in this review. Finally, the article concludes by outlining potential future research scope and challenges

Optimization of anodizing parameters for the morphological properties of TiO2 nanotubes based on response surface methodology

TiO2 nanotube (TNT) morphology is crucial for applications in a variety of fields. In this paper, response surface methodology (RSM) has been utilized to optimize the anodizing parameters i.e., electrolyte concentration (C), anodization voltage (V), and time (t) for morphology (e.g., nanotube diameter and length) of TNTs. Ethylene glycol (EG) based electrolyte has been used for anodization employing ammonium fluoride (NH4F) as a source of fluoride ion (F–) with 2.5 vol% H2O. Reliable regression models have been developed between the input variables and the corresponding responses, namely tube diameter and length with multiple regression coefficients of 0.9649 and 0.9253, respectively, revealing a trustworthy association between the actual and those predicted values using the quadratic model. The predicted values of C (0.31 wt%), V (38.44 V), and t (69.37 min) were found to be the optimum anodization condition preceding a TiO2 nanotubes diameter of 99.31 nm and length of 4572.64 nm. It was observed that the nanotubes diameter and length are more affected by anodizing voltage and time, and less sensitive to NH4F concentration. Therefore, RMS could be an appropriate technique to optimize anodizing parameters for producing TiO2 nanotubes with good morphology

Recent progress in TiO2-Based photocatalysts for conversion of CO2 to hydrocarbon fuels: A systematic review

Photocatalytic conversion of CO2 by using sunlight and TiO2 photocatalysts is a promising approach which produce hydrocarbon fuels to meet the future energy demands with hardly affecting the environment. This systematic review aims to provide rigorous overview of recent progress in TiO2-based CO2 photoreduction to produce hydrocarbon fuels along with future challenges. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method was adopted to perform this systematic review. It uses explicit systematic approaches that are chosen to prevent bias, resulting in accurate data collection which helps to draw reliable conclusions. Peer-reviewed articles published in English language between year 2018–2022 were chosen from two main databases, namely Web of Science and Scopus. Depending on the search criteria 62 articles were selected for reviewing critically. Literature suggests that TiO2-based photocatalysts have been increasingly used for reducing CO2 to hydrocarbon fuels. Morphological alterations and surface modification techniques have been widely utilized to improve the photocatalytic performance and minimize limitations of pure TiO2. Despite extensible efforts in this field, the utilization of hydrocarbon fuels still far away from practical applications. There are some challenges need to be addressed like environment friendly low-cost synthesis and modification method development, maximum visible light utilization, design of photoreactor with suitable product selectivity and kinetic model development for CO2 reduction. This study portrays increased clarity regarding the advances and way forwards of crucial topics TiO2-based CO2 photoreduction. Such systematic review is crucial for researchers and academicians for setting future planning

A comprehensive review on advances in TiO2 nanotube (TNT)-based photocatalytic CO2 reduction to value-added products

The photocatalytic reduction of CO2 into solar fuels by using semiconductor photocatalysts is one of the most promising approaches in terms of pollution control as well as renewable energy sources. One of the crucial challenges for the 21st century is the development of potential photocatalysts and techniques to improve CO2 photoreduction efficiency. TiO2 nanotubes (TNTs) have recently attracted a great deal of research attention for their potential to convert CO2 into useful compounds. Researchers are concentrating more on CO2 reduction due to the rising trend in CO2 emissions and are striving to improve the rate of CO2 photoreduction by modifying TNTs with the appropriate configuration. In order to portray the potential applications of TNTs, it is imperative to critically evaluate recent developments in synthesis and modification methodologies and their capability to transform CO2 into value-added chemicals. The current review provides an insightful understanding of TNT production methods, surface modification strategies used to enhance CO2 photoreduction, and major findings from previous research, thereby revealing research gaps and upcoming challenges. Stability, reusability, and the improved performance of TNT photocatalysts under visible light as well as the selection of optimized modification methods are the identified barriers for CO2 photoreduction into valuable products. Higher rates of efficacy and product yield can be attained by synthesizing suitable photocatalysts with addressing the limitations of TNTs and designing an optimized photoreactor in terms of the proper utilization of photocatalysts, incident lights, and the partial pressure of reactants