MAGNETICALLY MODIFIED SUGARCANE BAGASSE BIOCHAR AS CADMIUM REMOVAL AGENT IN WATER

Heavy metals are hazardous to health at certain levels. Currently, heavy metals are removed by physicochemical treatments, such as adsorption, flotation, and electrochemical deposition, and also biological treatments, such as algal biofilm reactor and anaerobic ammonium oxidation. In this study, magnetic biochar was produced to enhance the effectiveness and performance of the adsorbent for heavy metal removal. This study aimed to synthesise high-performance magnetic biochar, to determine the optimum parameters and conditions for high yield of magnetic biochar and high removal of cadmium (Cd2+) from aqueous solution, and to determine the adsorption kinetics and isotherms for Cd2+ removal. Nickel oxide (NiO)-impregnated sugarcane bagasse was subjected to slow pyrolysis to produce magnetic biochar. The impregnated metal, pyrolysis temperature, and pyrolysis time were varied to determine the optimum parameters and conditions to produce high-performance magnetic biochar. The removal of Cd2+ from aqueous solution and batch adsorption study were conducted. The synthesised magnetic biochar was characterised using field-emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area, Fourier transform infrared (FTIR), and vibrating sample magnetometer (VSM). The adsorption data agreed well with the pseudo-second-order model and followed the Langmuir isotherm model. This study achieved 88.47% removal efficiency of Cd2+ from aqueous solution. Thus, the removal of this heavy metal as a human carcinogen reduces the hazardous effects on human health and reduces the toxicity in the environment. ABSTRAK: Logam berat adalah berbahaya bagi kesihatan di peringkat tertentu. Pada masa ini, logam berat disingkirkan melalui rawatan fizikokimia, seperti penyerapan, pengapungan, dan deposit elektrokimia, dan rawatan biologikal, seperti reaktor biofilem alga dan oksidasi ammonium anerobik. Kajian ini menghasilkan biochar magnetik bagi meningkatkan keberkesanan dan prestasi penyerapan penyingkiran logam berat. Kajian ini bertujuan bagi mengsintesis biochar magnetik pada prestasi tinggi, bagi menghasilkan parameter optimum dan keadaan pengeluaran tinggi biochar magnetik dan penyingkiran tinggi kadmium (Cd2+) daripada larutan akues, dan bagi mendapatkan penyerapan kinetik dan isoterma penyingkiran Cd2+. Nikel oksida (NiO)-impregnat hampas tebu adalah berdasarkan pirolisis perlahan bagi menghasilkan biochar magnetik. Logam yang terimpregnat, suhu pirolisis dan tempoh pirolisis dipelbagaikan bagi mendapatkan parameter optimum dan keadaan bagi menghasilkan biochar magnetik berprestasi-tinggi. Penyingkiran Cd2+ daripada larutan akues dan kajian penyerapan berkumpulan telah dibuat. Biochar magnetik yang disentisis diklasifikasikan menggunakan mikroskopi elektron imbasan medan-pancaran (FESEM), tenaga sebaran X-ray (EDX), pembelauan X-ray (XRD), kawasan permukaan Brunauer-Emmett-Teller (BET), Penjelmaan Fourier inframerah (FTIR), dan sampel getaran magnetometer (VSM). Data penyerapan menunjukkan persetujuan dengan model aturan-kedua-pseudo dan mengikuti model isoterma Langmuir. Kajian ini mencapai 88.47% keberkesanan penyingkiran Cd2+ daripada larutan akues. Oleh itu, penyingkiran logam berat ini sebagai karsinogen manusia mengurangkan kesan teruk pada kesihatan manusia dan pengurangan toksik pada alam sekitar.

Optimization of parameters affecting dealcoholization of anthocyanin extract by liquid emulsion membrane using response surface methodology

Colour is one of most important properties of foods and beverages and is a basis for their identification and acceptability. Anthocyanin from red cabbage was extracted using 50 % ethanol. The extract was dealcoholized by Liquid Emlusion Membrane technology (LEM). Parafin oil was used as a solvent, lecithin was used as a surfactant and water as stripping medium. Response surface methodology (RSM) was used to design the experiments. A total of 30 experiments were conducted in accordance with central composite rotatable design. Design expert 8 was used to design the experiments. % extraction of alcohol in each case was determined. A suitable model was fitted to experimental data by regression analysis (R-square=0.93). Response surface plot were analysed and optimum parameters for dealcoholization were found to be speed=365.44 rpm, time=18.62 min, concentration of lecithin=2.84 %, feed to emulsion ratio=3.05. A maximum dealcoholisation of 18.63 % was observed under these conditions

Optimization of Process Parameter in Wire Electrical Discharge Machining of H11 Tool Steel Using Response Surface Methodology

Conventional machining is now being superseded by non-conventional machining to cope up with increased demand of machining of complex shapes with high surface finish machining and dimensional accuracy. Wire electric discharge machining (WEDM) is electro-thermal principle based nontraditional machining, widely used for machining of electrically conductive materials. This paper summarized, the parametric influence of Pulse-on duration (Ton), Pulse-off duration (Toff) and Pulse peak current (Ip) on material removal rate (MRR), surface roughness (SR) of H11 tool steel. Response surface methodology (RSM) is used for modelling and optimization. ANOVA has been carried out to identify importance of the machining parameters on the performance characteristics considered. Further the verification experiment has been carried out to confirm the performance of optimum parameters. The results from this study will be useful for selecting appropriate set of process parameters to WEDM machining of H11 tool steel.

Enhancement of Delignification and Glucan Content of Sugarcane Bagasse by Alkali Pretreatment for Bioethanol Production

The current work aimed to enhance the delignification of sugarcane bagasse (SCB) for bioethanol production. The optimization of alkali (sodium hydroxide) pretreatment parameters such as concentration and residence time was carried out by the Taguchi method using L16 orthogonal array with two factors and four levels. Sugarcane bagasse powder was mixed with sodium hydroxide (NaOH) solution (0.5-2 wt.%) and heated in an autoclave at 121°C and at varied times (30-120 min). From the statistical analysis of data, it was observed that delignification and glucan increased with the increased concentration and short time. The optimum parameters of NaOH pretreatment were 2 wt.% of NaOH concentration and 30 minutes of residence time. At the optimum conditions, 86.8% delignification and 46.6% glucan content of SCB were obtained. Thus, alkali pretreatment optimized by Taguchi design is the effective method to remove lignin and to increase cellulose or glucan content in sugarcane bagasse for facilitating the further catalytic hydrolysis in bioethanol production.

Copper and Zinc Recovery from Sulfide Concentrate by Novel Artificial Microbial Community

Exploring efficient methods to enhance leaching efficiency is critical for bioleaching technology to deal with sulfide concentrate. In our study, a novel artificial microbial community was established to augment the bioleaching efficiency and recovery of copper (Cu) and zinc (Zn). The optimum parameters in bioleaching experiments were explored according to compare a series of conditions from gradient experiments: the pH value was 1.2, temperature was 45 °C, and rotation speed was 160 r/min, which were different with pure microorganism growth conditions. Under optimal conditions, the result of recovery for Cu and Zn indicated that the average leaching rate reached to 80% and 100% respectively, which almost increased 1.8 times and 1.2 times more than control (aseptic condition) group. Therefore, this method of Cu and Zn recovery using a new-type artificial microbial community is expected to be an environmentally-friendly and efficient bioleaching technology solution, which has the potential of large-field engineering application in the future.

Defect Analysis of 316 L Stainless Steel Prepared by LPBF Additive Manufacturing Processes

The 316 L stainless-steel samples were prepared by laser powder bed fusion (LPBF). The effects of processing parameters on the density and defects of 316 L stainless steel were studied through an orthogonal experiment. The density of the samples was measured by the Archimedes method, optical microscopy (OM) and X-ray Computed Tomography (XCT). The microstructures and defects under different LPBF parameters were studied by OM and SEM. The results show that the energy density has a significant effect on the defect and density of the structure. When the energy density is lower than 35.19 J/mm3, the density increases significantly with the increase of energy density. However, when the energy density is larger than this value, the density remains relatively stable. The process parameter with the greatest influence on energy density is the hatch distance D, followed by laser power P, scanning speed V and rotation angle θ. In this paper, the optimum parameters consist of P = 260 W, V = 1700 mm, D = 0.05 mm and θ = 67°, in which the density is as high as 98.5%. In addition, the possibility and accuracy of the XCT method in detecting the discontinuity and porosity of 316 L stainless steel were discussed. The results show that XCT can provide the whole size and variation trend of pores in the different producing direction of LPBF.

Control of the Automatic Voltage Regulator System with a Novel Stability-based Artificial Intelligence Method

This paper proposes a novel Stability-Based Artificial Intelligence Method for predicting the optimum parameters of the proportional-integral-derivative controller in an automatic voltage regulator system. To implement the stability-based artificial intelligence method, first, parameters which are of great importance for the control of the system are applied to the system randomly, data are collected, and then artificial intelligence studies are carried out. The suggested approach has been applied to the system and compared with other control methods in the literature, namely the improved Kidney Inspired algorithm, Jaya algorithm, Tree Seed algorithm, Water Wave Optimization, and Biography-Based Optimization to test the robustness of the new method. The numerical results indicate that the proposed method significantly outperforms all other methods.

Preparation and Properties of CO2 Micro-Nanobubble Water Based on Response Surface Methodology

Carbon dioxide (CO2) enrichment in an agricultural environment has been shown to enhance the efficiency of crop photosynthesis, increasing crop yield and product quality. There is a problem of the excessive use of CO2 gas when the CO2 is enriched for crops, such as soybean and other field crops. Given the application of micro-nanobubbles (MNBs) in agricultural production, this research takes CO2 as the gas source to prepare the micro-nanobubble water by the dissolved gas release method, and the response surface methodology is used to optimize the preparation process. The results show that the optimum parameters, which are the gas–liquid ratio, generator running time, and inlet water temperature for the preparation of CO2 micro-nanobubble water, are 2.87%, 28.47 min, and 25.52 °C, respectively. The CO2 content in the MNB water prepared under the optimum parameters is 7.64 mg/L, and the pH is 4.08. Furthermore, the particle size of the bubbles is mostly 255.5 nm. With the extension of the storage time, some of the bubbles polymerize and spill out, but there is still a certain amount of nanoscale bubbles during a certain period. This research provides a new idea for using MNB technology to increase the content and lifespan of CO2 in water, which will slow the release and increase the utilization of CO2 when using CO2 enrichment in agriculture.

Optimizing And Comparative of Polymer-45S5BG and Polymer- HA Coating by Electrophoretic Deposition (EPD)

In this study, two systems of bio-ceramic coating (45S5 bioactive glass and hydroxyapatite) were used in order to compare between them for biomedical applications. Each system consists from two layers of coating done by electrophoretic deposition (EPD) technique on 316L stainless steel material as substrate. Two types of biopolymer were used (Chitosan with Gelatin) as first layer of coating. Taguchi approach with L9 array was used in order to choose the best conditions (concentrations, voltage and time) for coating layers. Each system consists of two layer (biopolymer (first layer) and bioceramic (second layer)) materials. The optimum parameters for first layer of biopolymer was (3g/L concentration, 20 voltage and 3 minute) while optimum parameter for second layer (6g/L concentration, 30 voltage and 1 minute) for two bioceramic group. Zeta potential test were employed to measure suspensions stability. The tape test method was used to evaluate the adhesion between substrate and coating layers, the results show that the percentage of removal area for optimum coating layer (biopolymer, 45S5 BG and HA 8.06%, 10.668%, 6.23% subsequently). XRD inspection was used for identify the phases of coating layers. The Cyclic polarization test was used for evaluation of pitting corrosion resistance, the results show all layers gives good corrosion resistance but 45S5BG gives the best corrosion resistance when compared with HA system.