bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrochar production through co-hydrothermal carbonization of water hyacinth and plastic waste
Authors: Ong M Y , Nomanbhay S , Rosman C U A A C , Yusaf T , Silitonga A S 
Published: July 2024

Abstract
The global expansion of the economy and concerns about greenhouse gas emissions and climate change necessitate the exploration of sustainable alternatives to fossil fuels. Water hyacinth (WH) is globally recognized as one of the most problematic aquatic weeds, posing significant challenges to urban management by clogging waterways, polluting water sources, and causing harm to ecosystems. However, water hyacinth is enriched with hemicellulose, cellulose, and lignin, making it a noteworthy and superior biomass resource. Hence, this study focuses on the hydrothermal carbonization of water hyacinth into a renewable fuel source, the hydrochar. Hydrothermal treatment was implemented in this work as it can treat wet biomass, in this case, the water hyacinth, without the need of energy-extensive drying process. Plastic waste (PW), or more specifically low-density polyethylene (LDPE), was added as the co-feedstock during the HTC process with the purpose to boost the higher heating value (HHV) of the end product. The co-hydrothermal carbonization (co-HTC) process of the mixture of WH and PW at various ratios and temperatures were conducted to investigate the optimal HTC condition for high hydrochar yields. As the result, the highest hydrochar yield of 29.23 wt% was obtained with 12.5% LDPE substitution percentage, at 200 °C after a holding time of 90 min. However, in term of energy recovery efficiency (ER), the highest efficiency (27.28%) was achieved with 12.5% LDPE substitution percentage at 260 °C. The HHV value of the hydrochar produced in this work is in the range of 17.71-24.69 MJ/kg. In summary, the co-HTC of WH and LDPE could definitely be a promising alternative to bridge the gap from solid waste to renewable fuels.
Optimization of bio-oil production from macroalgae, caulerpa lentillifera via hydrothermal liquefaction
Authors: Ong M Y , Azmi N L , Nomanbhay S 
Published: July 2024

Abstract
An environmentally friendly method of producing bio-oil through the hydrothermal liquefaction (HTL) of algae has emerged, providing a path toward renewable energy and reducing greenhouse gas emissions. Algae is currently received a lot of interest as biomass feedstock due to its long growing season in warm climate area, does not require arable land, and relatively rapid growing rate. This study aims to optimize the HTL process of macroalgae (Caulerpa lentillifera) for bio-oil production, focusing on optimizing the bio-oil yield based on three parameters (operating temperature, the loading size of catalyst sodium hydroxide (NaOH), and algae-to-water ratio) using Box Behnken Design (also generally known as Response Surface Methodology). The results showed that an ideal reaction temperature of 277 °C, a 1:10 algae-to-water ratio, and 0.88 wt% catalyst loading led to an optimal experimental bio-oil yield of 11.65 wt%. Sensitivity study also revealed that the temperature is the second most important component, after the algae-to-water ratio. The difference in the catalyst loading showed low impact on the HTL of algae. Slight improvement to the bio-oil yield under the presence of NaOH is mainly due to the alkali environment provided by NaOH. The FTIR spectrum revealed the existence of various functional groups in the bio-oil. In summary, HTL has been effective in turning Caulerpa lentillifera into useful bio-oil. Overall, this study contributes to the growing body of research on algae-based bio-oil production. The results highlighted the potential of HTL as a promising technology for sustainable biofuel production, offering a pathway towards a greener and more energy-efficient future.
Emerging pollutants in waste water: Challenges and advancements in treatment technology
Authors: Corpus R M B , Bayani M S , Aguilar J L , Aguilar J C B , Aguilar H B 
Published: July 2024

Abstract
Microplastics, per- and polyfluoroalkyl substances (PFAS), pharmaceuticals and personal care products (PPCPs), and other emerging contaminants in wastewater have all caused serious environmental and public health issues. The effectiveness of conventional wastewater treatment techniques to remove these pollutants, such as activated sludge, membrane bioreactors, and coagulation-flocculation, is often insufficient. The difficulties and improvements in treatment technology for eliminating developing contaminants from wastewater are examined in this thorough review study. The review gives a general overview of the most important subcategories of emerging pollutants, the shortcomings of traditional wastewater treatment techniques, and the developments in treatment technologies, including advanced oxidation processes (AOPs), adsorption-based methods, and novel biological treatment approaches. The obstacles mentioned include the need for sustainable and energy-efficient solutions, regulatory and monitoring concerns, and technological and economic hurdles. A number of suggestions are made as a response to these difficulties, such as boosting oversight and regulating procedures, fostering cooperation and information sharing, encouraging industry participation, and supporting research and development. These suggestions may be put into practice in order to reduce the hazards posed by developing contaminants in wastewater and safeguard our water resources and the ecosystem over the long run. The article emphasizes the value of using a multidisciplinary and cooperative approach to solving the problems caused by new contaminants. In order to create original solutions, advance best practices, and build suitable regulatory frameworks, it underlines the necessity for ongoing research, policy development, and stakeholder collaboration. The ultimate goal of this analysis is to provide academics, decision-makers, industry stakeholders, and the general public with a useful resource in their quest to comprehend and resolve the complicated problem of developing contaminants in wastewater.
Hydrogen sulphide removal from raw biogas using novel coconut husk and sugarcane bagasse composite biochar adsorbent
Authors: Das B , Basumatary S , Kalita P 
Published: July 2024

Abstract
The presence of water, hydrogen sulfide (H2S), ammonia, oxygen, nitrogen, and siloxanes in biogas is not desirable for thermal and electrical applications through the engine route. H2S adversely affects engines and fuel cells by causing corrosion on metal components, poisoning catalytic converters, and accelerating wear and tear, compromising performance and longevity. To meet specific quality requirements for diverse applications such as heating, combined heat and power generation, vehicle fuel, and fuel cells, biogas must undergo cleaning and upgrading processes. Using biochar to remove H2S in biogas is a comparatively new technique and can be a promising option for small-scale, decentralized units. Current research primarily investigates the potential of biochar derived from coconut husk (CH) and sugarcane bagasse (SB) for effectively removing H2S from raw biogas within an experimental framework. The selection of a composite material consisting of equal parts CH and SB was based on available literature and material accessibility. The integrated methodology provided comprehensive insights into the performance of biochars in biogas purification. Morphological analysis elucidated the role of pore structure in facilitating H2S removal, while CHNS analysis highlighted the influence of elemental composition on biochar reactivity. Additionally, pH studies underscored the potential for biochar application to mitigate biogas acidity. According to the findings, the biochar from the combination of CH and SB exhibited a removal efficiency of 77.60% for H2S in raw biogas.
Waste separation intention of households in Sri Lanka
Authors: Shukri S , Jayasena D M 
Published: July 2024

Abstract
The effective practice of waste separation at the source is crucial for achieving sustainable development and promoting the reduce, reuse, and recycle concept. This practice should be adopted by both households and business organisations. The primary objective of this study is to investigate the factors that influence the intention of waste separation at the household level in Sri Lanka. For this purpose, a random selection of 388 households representing the entire country was undertaken. Independent variables, including attitude, perceived cost benefits, moral norms, inconvenience, and rules and regulations, were examined in relation to their impact on the dependent variable, which was the intention of waste separation. A 5-point Likert scale questiommaire was utilised to assess each of these variables. The methodology employed in this study included principal component analysis, factor analysis, and Structural Equation Model (SEM) to establish the underlying model. The results of the analysis revealed the significance of attitude, perceived cost benefits, and moral norms at a 5% significance level. Interestingly, although inconvenience exhibited a negative influence on intention, its significance was not established. Furthermore, while existing literature commonly attributed local government rules and regulations as a significant factor, the model indicated a positive and insignificant relationship. In conclusion, this study underscores the importance of positive attitudes, perceived benefits in terms of cost, and adherence to moral norms in fostering the intention for waste separation. Despite the negative impact of inconvenience not reaching statistical significance, it remains a noteworthy consideration. Additionally, the unexpected positive and insignificant relationship with local government rules and regulations prompts further exploration.
Prediction of nitrate, phosphate and ammonia removal in wastewater by phytoremediation-vortex system using artificial neural network
Authors: Cuevas D G , Pescos C J , Carrillo L , Sibal A , Guevarra N G 
Published: July 2024

Abstract
Clean water is an essential component for human survival. However, the growing global population and the relentless pace of industrial development have resulted in an alarming increase in water contamination. This renders many bodies of water as unfit for consumption or usage. In order to safeguard our natural resources, it is imperative that wastewater should be treated to follow a standard set by environmental specialists. In the Philippines, the enactment of the DAO 2021-19 has updated the requirements for release to more stringent standards. Because of this, a tertiary treatment, such as a phytoremediation bed, can be employed as an additional step in a wastewater treatment process. This study involves a comprehensive approach that consists of a phytoremediation setup, which includes the use of three plant species and specialized soil matrices, and a vortex system. The three plant species, Phragmites australis, Vetiveria zizanioides, and Canna indica are known for their capability for removal of the three pollutants, nitrates, phosphates and ammonia. The phytoremediation-vortex system was able to remove the pollutants and effectively reduce the pollutant concentration that the treated wastewater passes the standards for release. The predictive model, artificial neural network (ANN), was employed to assess the results. By using this technique, the study aimed to not only understand the intricate workings of the vortex system but also to optimise its performance for the effective reduction of pollutants, such as, nitrates, phosphates and ammonia, in wastewater. This research represents a critical step towards developing sustainable and efficient solutions for addressing the pressing challenges posed by water pollution, thereby fostering the availability of clean and potable water for human consumption and various industrial purposes.
Production of biodiesel from non-edible waste palm oil and sterculia foetida using microwave irradiation
Authors: Milano J , Tiong S K , Chia S R , Ong M Y , Sebayang A H , Kalam M A 
Published: July 2024

Abstract
The environmental damage stemming from traditional diesel begins during crude oil extraction and persists throughout its usage. The burning of fossil fuels has further deteriorate the environmental effect and added to global warming by emitting harmful substances. Moreover, the reduction of finite fossil fuel reserves due to widespread extraction has made the adoption of renewable resources essential. Given these considerations, biodiesel emerges as a highly promising alternative to conventional diesel due to its environmentally beneficial nature, renewable source, and economic feasibility. In this study, biodiesel was prepared by a microwave reactor in the presence of potassium methoxide using blended waste palm oil and sterculia foetida. The effects of raw materials characteristics on transesterification products were studied. The studied process parameters were methanol/oil ratio, microwave temperature, catalyst concentration, reaction time, and stirring speed. The optimal yield with 98.5% FAME content was obtained at a methanol/oil ratio of 60 vol. %, microwave temperature of 120 °C, catalyst concentration of 0.3 wt.%, and 3 min reaction time, and stirring speed of 500 rpm. The potassium methoxide was used to catalyse the transesterification process. The physicochemical properties and the fatty acid methyl ester composition were discussed thoroughly. The flash point of biodiesel, at 157.5°C, exceeds that of diesel fuel by more than two times. The cetane index is 59.5 which is higher than diesel (49.6). The biodiesel’s fuel properties conformed to the requirements of both ASTM D6751 and EN 14214. High biodiesel conversion and low sulphur content show that waste palm oil and sterculia foetida are sustainable and economical feedstocks that produce clean fuel to aid the feasibility of the energy transition of the global energy sector. In addition, the selection of synthesis approaches can be further explored for potential catalysts to ensure eco-green biodiesel’s sustainability with minimised.
Production of green diesel from waste cooking oil via catalytic deoxygenation reaction using metal doped eggshell catalyst
Authors: Lee Z S , Seah C C , Habib S H , Hafriz R S R M , Razali N M 
Published: July 2024

Abstract
Green diesel production via catalytic deoxygenation of waste cooking oil (WCO) over metal doped eggshell catalyst was investigated in this work. The catalyst was prepared through liquid-liquid precipitation of 5 transition metal solutions and ground eggshell (ES) as the catalyst support. The prepared catalyst, Fe-ES, Cu-ES, Co-ES, Zn-ES, and Ni-ES were characterized using BET surface area and Scanning Electron Microscopy (SEM) analysis. BET surface area data and SEM images of the catalyst shows a promising catalyst physical properties that tailor to the deoxygenation reaction. Gas Chromatography Mass Spectrometry (GCMS) was used to determine the hydrocarbon composition of the oil yield product from the reaction. The reaction also produces gas, soap and liquid acid phase while the remaining unreacted WCO becomes coke. The percentage of all products and coke were calculated using mass balance. Deoxygenation of WCO with Ni-ES catalyst produced highest oil yield at 61.6% with the hydrocarbon content of 56.11%. Ni-ES also produced 22.9% coke; the least percentage compared to other catalyst. The findings proved that Ni-ES catalyst exhibited the highest conversion of WCO into gas and liquid product with a greater yield of oil and minimal coke formation. These findings demonstrate the feasibility and practicality of using eggshell catalysts as substitutes for commercial catalysts in green diesel production.
Sensitivity analysis on heat pump - mechanical vapor recompression desalination system by recovering waste heat of offshore power converter station
Authors: Shi C Y , Hu X W , Dong S M , Fu X Y , Liu T , Jin M S 
Published: July 2024

Abstract
Offshore wind power converter stations produce massive low-temperature waste heat, which can hardly be used constrained by their offshore location. Therefore, the recovery of the waste heat has been raising widespread concern. Meanwhile, a large amount of fresh water is needed for its cooling system. So, a novel system combining high temperature heat pump and a mechanical vapor recompression system (HP-MVR) was proposed, and sensitivity analysis was performed to optimize it. The heat pump was used to absorb the waste heat and to produce high temperature water. The mechanical vapor recompression system was adopted to produce fresh water and to recover the condensation heat from the steam. In order to determine the impact parameters on the two crucial performance indicators of freshwater production and unit energy consumption, this article introduces a sensitivity analysis method, focusing on analyzing the sensitivity of the three operating parameters of heat pump condensation temperature, saturated water vapor inlet temperature entering the compressor, and freshwater condensation temperature to these two performance indicators. The results show that the sensitivity coefficients of heat pump condensation temperature, saturated water vapor inlet temperature entering the compressor, and freshwater condensation temperature are 1.13, -0.26, and 1.56. So, the freshwater condensation temperature has the most significant effect on freshwater output. Their sensitivity coefficients to unit energy consumption are 1.02, 1.41, and -0.64. The saturated water vapor inlet temperature entering the compressor has the most significant impact on the required power consumption per unit of freshwater. It will give some guidance for the application of low-temperature waste heat in seawater desalination and the reduction of operating costs.
On application of molecular dynamics simulation for studying the effect of temperature and heating rate on HTL of biomass
Authors: Trinh Thuat T , Tran Khanh-Quang 
Published: July 2024

Abstract
Hydrothermal liquefaction (HTL) of biomass has garnered increasing attention as a promising pathway for converting solid biomass to liquid biofuels and valuable chemical products. HTL involves processing of biomass in water at high-temperature and high-pressure conditions. The heating rate during this process plays a critical role in determining the yield and composition of the liquefied products. To probe the impact of heating rate, we develop a detailed atomistic model biomass by using cellulose as model compound and place it in a simulated HTL reactor. Our Reactive molecular dynamics simulations are capable of capturing the dynamic chemical reactions and structural changes during HTL. The effect of reaction temperature and heating rates on reaction pathways, product distributions, and reaction kinetics is rigorously analyzed. Our findings reveal that the reaction temperature and heating rate significantly influences the extent of cellulose degradation and the composition of bio-oil product.
Performance evaluation of pilot phyto-vortex integrated system in the reduction of wastewater pollutants
Authors: Guevarra NG , Cuevas DG , Pescos CJ , Sibal A , Carrillo L 
Published: July 2024

Abstract
Wastewater pollution remediation connects to goal 6 of the United Nations 17 Sustainable Development Goals (SDG) ensuring availability and sustainable management of water and sanitation for all. Conventional and advanced wastewater treatment are quite expensive to operate to fully comply with regulatory standards in the country. Phyto-vortex integrated system is an alternative tertiary wastewater treatment system that interfaces with an oil and grease skimmer and vortex technology, relying on green plants and a variety of soil substrates to remediate wastewater. The research evaluated the potential of the Phyto-vortex system and its performance in the reduction of domestic wastewater pollutants. Plants and soil substrates were selected via Analytic Hierarchy Process (AHP) using one-way sensitivity analysis. Common reed, Vetiver grass, and Canna Lily were planted in constructed reed beds with various soil matrices using substrates laid at different levels. The beds operate continuously as a horizontal subsurface flow treating 5 m3 of a sewage treatment effluent per day with 1-3 days hydraulic retention time (HRT). The vortex unit aerates the water for further removal of gaseous pollutants. Samples were taken at designated points for 18 weeks. Analysis of the results shows a maximum reduction of 92% for biochemical oxygen demand (BOD), 60 % for chemical oxygen demand(COD), and 70 % for total suspended solids (TSS). Concentration of identified heavy metals in the influent are within the regulatory standards except for a rise in zinc concentration which was 97% reduced in the system. The percentage reduction of pollutants varies each week with nitrates decreasing in the range of 50% to 99%, phosphates from 8% to 39.5%, and ammonia from 45.65% to 99%. Varying environmental conditions such as monsoon rains and extreme heat caused algal blooms and plant disease affecting the results. Lower temperatures and lower humidity favor a decrease in the levels of the pollutants while higher temperature, higher humidity favor an increase in the levels of Nitrates, Phosphates, and Ammonia. The overall results show an effective integrated system of phytoremediation coupled with a vortex unit in the reduction of wastewater pollutants.
Life Cycle Assessment of Large-Scale Solar Photovoltaic Plant based in Malaysia
Authors: Quek A , Abbas A R , Zaman N Z I S , Ata W N S W , Zainal M F , Yapandi F K M , Ibrahim Z F , Suhardi A 
Published: July 2024

Abstract
A cradle-to-grave life cycle assessment (LCA) has been performed on a Large Scale Solar Photovoltaic (LSSPV) plant based in Peninsular Malaysia to study the detailed environmental impact of its life cycle. The LSSPV, with a capacity of 78 MWdc, is currently one of Malaysia’s largest solar power plants. The different life cycle phases of the LSSPV, starting from resource manufacturing and transportation, through plant construction and electricity generation, and to decommissioning of the plant, were assessed using the SimaPro software with the Ecoinvent v3.8 database. Results show that the overall emission rate for the LSSPV is 0.0309 kgCO2eq/kWh. It is estimated that the construction phase of the power plant, which includes activities such as infrastructure works and production of PV modules and Balance of System, yields the largest amount of kgCO2eq/kWh emission at 85.7% and imposes the highest environmental impact as compared to the other phases. The second biggest contributor is attributed to the transportation phase, contributing to 14.0% of the total kgCO2eq/kWh emission, of which most of the emission is emitted during the sea freight transportation of PV components from China port to Malaysia port (12.4%). A sensitivity analysis was performed to compare the environmental impact between open ground installation and the slanted roof installation mounting system of LSSPV. The findings from LCA proposed that open-ground installation has a greater negative impact on the environment because it involves additional land clearing and infrastructure transformation. The findings from this study serve as a benchmark for the LSSPV system in Malaysia and present technical perspectives for the future development of PV projects considering environmental impacts across the project lifetime.