Removal of bisphenol S from aqueous solution using activated carbon derived from rambutan peel via microwave irradiation technique

Bisphenol S (BPS) was introduced to replace Bisphenol A (BPA) in plastic production. Unfortunately, recent studies have shown that BPS is toxic. This study explores the conversion of rambutan peel into rambutan peel-based activated carbon (RPAC) via the economic route of single-stage microwave irradiation technique at radiation power and radiation time of 440 W and 6 min, respectively, under CO2 gasification. The resulted RPAC posed BET surface area of 402.68 m2/g, mesopores surface area of 332.98 m2/g, total pore volume of 0.23 cm3/g, and average pore diameter of 2.26 nm, which lies in the mesopores region. The surface of RPAC was filled with various functional groups such as methylene, aliphatic fluoro, phenol, nitro, and alkyl compounds. Adsorption of BPS onto RPAC achieved equilibrium faster at lower BPS initial concentration as compared to the higher ones. Isotherm study found that the Langmuir model suits this adsorption process the best with a maximum monolayer adsorption capacity of 27.89 mg/g whereas the kinetic study showed that pseudo-second order (PSO) represented the kinetic data the best. Intraparticle diffusion plots suggested that the adsorption process consisted of three regions and each region was controlled by a different type of diffusion mechanism. Boyd plot confirmed that film diffusion was responsible for the slowest step in the adsorption process whilst thermodynamic parameters disclosed that adsorption of BPS onto RPAC was spontaneous, exothermic, governed by physisorption, and the randomness of the adsorption process was found to reduce at the solid-liquid interface

Influence of parental dura and pisifera genetic origins on oil palm fruit set ratio and yield components in their D × P progenies

This research was conducted to study the performance of biparental dura × pisifera (D × P) progenies and their parental genetic origins on fruit set and yield components. Twenty-four D × P progenies developed from 10 genetic origins were used for this study. Analysis of variance showed that there was genetic variability based on the evaluation of individual progenies. Deli Ulu Remis × Nigeria of progeny ECPHP500 recorded the highest bunch number (22.91), and fresh fruit bunch (184.62 kg palm−1 year−1) and Deli Banting dura × AVROS pisifera (ECPHP550) had the highest average bunch weight (10.36 kg bunch−1 year−1). Progenies PK4674 (61.12%) and PK4465 (60.93%) had the highest fruit set, and the highest oil yield of 52.66 kg bunch−1 was noticed by progeny PK4674. Estimation of variance components, coefficients of variation, heritability, and genetic gain were calculated to establish the genetic variability. To validate the genetic disparity among the progenies, an unweighted pair-group procedure with arithmetic mean (UPGMA) and principal component was employed based on their quantitative traits. Through the UPGMA and principal component, the 24 progenies were clustered into 7 clusters, whereas cluster V had the highest fruit set (60.62%) and cluster IV had the highest oil yield (43.71 kg palm−1 year−1). For oil palm tissue culture and breeding programs, progeny PK4674 will be more useful for developing planting materials of high oil yielding with stable performance. However, we recommend that future studies incorporate molecular studies with conventional breeding

Alteration of Tecoma chip wood waste into microwave-irradiated activated carbon for amoxicillin removal: Optimization and batch studies

Amoxicillin (AMOX) in wastewater can promote antibiotic resistance in bacteria and affecting aquatic ecosystems, due to inadequate removal by conventional wastewater treatment plants. This study aimed to (i) optimizing Tecoma chip wood based activated carbon (TCAC) to adsorb amoxicillin (AMOX) using response surface methodology (RSM) and (ii) evaluating AMOX adsorption through batch and continuous modes. The RSM revealed the optimum conditions to be 657 W, 20 min and 0.99 g/g for radiation power, radiation time and impregnation ratio (IR), respectively. These optimum conditions resulted in AMOX removal efficiency of 88.07 mg/g and 27.68 % of TCAC’s yield. The BET surface area and total pore volume of TCAC were 924.85 m2/g and 0.3485 cm3/g respectively. The surface of TCAC was occupied with several functional groups namely primary amine, hydroxy, alkyl carbonate and terminal alkyne. These functional groups enhanced the adsorption process by forming hydrogen bond with AMOX molecules. The isotherm study revealed that AMOX-TCAC adsorption system obeyed the Langmuir model and the maximum monolayer adsorption capacity, Qm is 357.14 mg/g. Pseudo-second order (PSO) model fitted the best for the adsorption of AMOX by TCAC in the kinetic studies. Boyd plot divulged that the rate limiting step in the adsorption process was the film diffusion. Thermodynamic study confirmed the adsorption process to be endothermic, spontaneous and controlled by physisorption. In bed column studies, the percentage removal of adsorbates was found to increase when the adsorbates flowrate decreased, adsorbates initial concentration decreased, and bed height increased. For the breakthrough curve model, the adsorption is best fitted to Yoon Nelson model. TCAC demonstrated its efficacy in the removal of AMOX, proving successful in both batch mode and continuous mode operations. These findings suggest the potential for scaling up TCAC production for industrial purposes, indicating its suitability for larger-scale applications

Mass transfer simulation on remazol brilliant blue R dye adsorption by optimized teak wood Based activated carbon

The reactive dye of remazol brilliant blue R (RBBR) can be toxic to aquatic ecosystems and humans. Hence, the objectives of this study were to optimize teak wood-based activated carbon (TWAC) via response surface methodology (RSM) to adsorb RBBR and to simulate the mass transfer process using Polymath software. The optimum conditions in preparing TWAC were discovered to be 470 Watt of radiation power, 6.40 min of radiation time, and 1.48 g/g of impregnation ratio (IR), resulting in RBBR uptakes of 83.97 mg/g and TWAC’s yield of 30.60%. Isotherm study revealed that the adsorption of RBBR onto TWAC was best described by the Langmuir model with maximum monolayer adsorption capacity, Qm of 337.55 mg/g. The kinetic data were best described by the Polymath Mass Transfer (PMT) model where the rate constant, kPTM was found to increase from 4.84 to 5.22 h−1 when RBBR initial concentration increased from 25 to 300 mg/L. The PMT model predicted the adsorption surface area, am to be 940.79 m2/g, which is highly accurate with the actual mesopores surface area of 983.25 m2/g. The RBBR molecules formed an attraction force with TWAC’s surface functional groups through hydrogen bond (cyclohexane), dipole–dipole force (polysulfides and terminal/medial alkyne), and ion–dipole force (phenol and hydroxy group). Thermodynamic parameters of ΔH°, ΔS°, ΔG°, and Ea were computed to be −3.55 kJ/mol (exothermic), 0.07 kJ/mol.K, −24.37 kJ/mol (spontaneous) and 21.23 kJ/mol (physisorption), respectively

Optimization and mass transfer simulation of remazol brilliant blue R dye adsorption onto meranti wood based activated carbon

Remazol brilliant blue R dye (RBBR) brings toxicity to living organisms once it enters the environment. This study utilized response surface methodology (RSM) and Polymath software for optimization and mass transfer simulation purposes, respectively. RSM revealed that the optimum preparation conditions of meranti wood-based activated carbon (MWAC) were 441 W, 5.76 min, and 1.35 g/g for radiation power, radiation time, and KOH:char impregnation ratio (IR), respectively, which translated into 86.39 mg/g of RBBR uptakes and 31.94 % of MWAC’s yield. The simulation study predicted the mass transfer rate, rm to be 112.20 to 1007.50 s−1 and the adsorption rate, k1 to be 3.96 to 4.34 h−1. The developed model predicted the adsorption surface area, am to be 790.04 m2/g and this value is highly accurate as compared to the actual mesopores surface area of 825.58 m2/g. Mechanism analysis divulged that the interaction that occurred between RBBR molecules and MWAC’s surface were hydrogen bond (methylene and alkyne), dipole–dipole force (alkyl carbonate, terminal alkyne, and methoxy), and ion–dipole force (primary amine). The isotherm and kinetic studies found that the adsorption data obeyed the Freundlich model and pseudo-first-order (PFO) model the best, respectively. The Langmuir maximum adsorption capacity, Qm was computed to be 327.33 mg/g. Thermodynamic parameters were calculated to be −4.06 kJ mol−1, 0.06 kJ mol−1 K−1, –22.69 kJ mol−1, and 16.03 kJ mol−1 for ΔH°, ΔS°, ΔG°, and Ea, respectively, which signified the adsorption process studied was exothermic, spontaneous and governed by physisorption

Chassis dynamometer for electric two wheelers

In recent years, electric two-wheelers are emerging as one of the alternatives to improve the sustainability of transportation energy and air quality, especially in urban areas. Although electric two-wheeler motorcycles are environmentally friendly, they underperform compared with gasoline two-wheelers in many respects, particularly in speed and cruise distance between refuelling and recharging. Therefore, the engine development program can be done with a dynamometer. Variables such as the shape of torque and power curves can be analyzed. Hence, this project is aimed to develop a chassis dynamometer that can be used to measure mechanical power, speed and torque, and provide a controllable load to the electric motorcycle being tested. The prototype of chassis dynamometer for electric motorcycle had been developed and performance of the chassis dynamometer was tested by using an electric bicycle to emulate the basic performance requirements of an electric motorcycle which consist of maximum speed, driving range and acceleration

A review on electric two wheelers

South East Asian cities such as Kuala Lumpur, Jakarta and Bangkok rely heavily on motorcycles. A huge number of urban residents depend on motorcycles for all types of activities such as working, ridehailing and delivery services, going to school or leisure. According to Malaysia Automotive Association (MMA) statistics, there are about 13 million registered motorcycles in Malaysia as of August 2017. The pollutants that a four-stroke-engine 50 cc motorcycle emits per kilometre are usually much higher than a 2-litre passenger car; 2.7 times higher for CO and 6.7 times higher for HC and NOX. Controlling excessive air pollution and emissions levels generated by the use of a motorcycle is one of the keys to improving air quality. Electric two-wheelers have been well adopted in Asia Pacific countries like China and Taiwan. This paper provides extensive review and analysis on development history, environmental and mobility impacts, challenge and limitation of electric two-wheelers from around the world and the potential of its emergence in Malaysia