Valorisation of Cocoa ( Theobroma cacao ) pod husk as precursors for the production of adsorbents for water treatment

Biofuels Bioprod Bioref

et al. 2020

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Typical municipal solid waste (MSW) is composed mainly of biomass and polymers. In this study, the co-conversion of a feedstock obtained from a mixture of both constituent materials is investigated. The goal of this study was to determine the suitability of a low-temperature process for achieving biochar with properties that can make it amenable to multiple energy and environmental applications. Co-carbonization of oil palm (Elaeis guineensis) fiber (OPF) and low-density polyethylene (LDPE) was conducted at a peak temperature of 529 °C for 80 min in a top-lit updraft biomass conversion reactor using retort heating. The biochar yields for OPF and OPF-LDPE were 15.9 wt% and 62.7 wt%, respectively, with the higher yield of the latter attributed to a polymer effect. The OPF and OPF-LDPE biochars were mesoporous with relatively large specific surface areas of 352.9 and 391.4 m 2 g −1 , respectively. The addition of LDPE to the OPF feedstock was observed to be advantageous as it improved the biochar yield, carbon content, specific surface area, and pore volume. Consequently, the technology of choice for solid waste management offers key environment-friendly benefits such as no electrical power requirement, an excellent waste-to-wealth approach, and the capacity to be used globally (in remote locations).

Section: Resultsmentioning

confidence: 99%

Section: Biochar Textural Characteristicsmentioning

confidence: 99%

Thermochemical conversion of oil palm Fiber‐LDPE hybrid waste into biochar

Adelodun

Adeniyi

Biofuels Bioprod Bioref

et al. 2020

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“…Maximum adsorption is observed at about 145 min of equilibration. This trend is because at lesser shaking time, equilibrium will not have been achieved; hence, the transfer of adsorbate from the solution to the adsorbent surface would not have been completed, leading to a lesser removal efficiency (Eletta et al 2020).…”

Section: Parametric Studies For Zn(ii) Biosorptionmentioning

confidence: 99%

Response surface modelling of the biosorption of Zn(II) and Pb(II) onto Micropogonias undulatus scales: Box–Behnken experimental approach

Eletta

2020

Appl Water Sci

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In this study, the scales of Micropogonias undulatus fish were investigated as precursors for the development of low-cost biosorbent for the removal of Pb(II) and Zn(II) from aqueous media. The biosorbent was characterised using Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and X-ray diffractometry (XRD). Adsorption parameters (temperature, biosorbent dosage and contact time) were optimised using response surface methodology Box-Behnken experimental design. The optimal factors for Zn(II) removal by croaker fish scale were 145.5 min, 7.01 g/L biosorbent dosage, 30 °C and pH 5.4. The optimal factors for the removal of Pb(II) were 179.3 min, 6.61 g/L biosorbent dosage, 20 °C and pH 3.4. The numerical optimisation revealed that the optimal removal efficiency for Zn(II) and Pb(II) sorption is 96.45% and 98.76%, respectively. The biosorption of both heavy metals was best fit to Freundlich isotherm and pseudo-second-order kinetic models. Thermodynamics studies revealed that the biosorption process was exothermic and spontaneous. Keywords Biosorption • Croaker • Fish scales • Heavy metals • Box-Behnken Abbreviations AAS Atomic absorption spectrophotometry ANOVA Analysis of variance BBD Box-Behnken design Df Degree of freedom DOE Design of experiments FS Fish scales FTIR Fourier transform infrared spectroscopy Rpm Rounds per minute RSM Response surface methodology SEM Scanning electron microscopy XRD X-ray diffractometry List of symbols α Temkin isotherm constant (equilibrium binding constant) (L/mol) Ǻ Armstrong b Temkin constant related to the adsorption heat β Constant related to adsorption energy (mol 2 /J 2) C Constant of the thickness of boundary layer C e Equilibrium concentration (mg/L) C i Initial concentration (mg/L) C L Equilibrium concentration in the liquid phase C S Equilibrium concentration in the solid phase K F Freundlich constant (mg/g) K E Equilibrium constant K 1 Rate constant of the pseudo-first-order model (min −1) K 2 Rate constant of the pseudo-second-order model (gm g −1 min −1) K dif Intra-particle diffusion rate constant (mg/ gmin 0.5) K L Langmuir constant related to affinity (l/g) n Freundlich constant q e Amount of chemical species removed at equilibrium (mg/g) q max Maximum metal uptake (mg/g)

“…Majorly, this wastewater is discharged without treatment due to the high cost and complexity associated with conventional treatment of wastewater (UNESCO, 2017). The use of biomass is typically simple, low energy, cheap and effective method of increasing the quality of wastewater before discharge by reducing impurities and absorbing heavy metals (Eletta et al, 2020;Ighalo and Adeniyi, 2020a). Biomass can be used as precursors for developing other advanced materials for water treatment (Ashouri et al, 2019;Ghasemipour et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

Evaluation of <i>Luffa Cylindrica</i> Fibers in A Biomass Packed Bed for The Treatment of Paint Industry Effluent Before Environmental Release

EUROPEAN J SUSTAINAB DEV

Adeniyi

Oke

et al. 2020

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The aim of this study was to investigate the potential of Luffa Cylindrica fibers in a biomass packed bed for the treatment of paint industry effluent before releasing into the environment. The fibers were modified by mercerisation in 0.5M NaOH for 24 h. Both modified and unmodified fibers were characterised using Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy (SEM-EDS). A biomass packed bed was prepared for the study with a packing factor of 0.0617 and 0.0550 for the modified and unmodified fibers respectively. Measured parameters were the pH, colour, total dissolved solids (TDS), total suspended solids (TSS), dissolved oxygen (DO), chemical oxygen demand (COD) and biochemical oxygen demand (BOD). Negative findings were achieved for TSS, DO and COD whilst positive findings were achieved for pH, colour, TDS and BOD. The extended residence time of 48 h was only of advantage for colour and BOD removal. In the domain of the positive results, the untreated fibers achieved 35% colour reduction, 5% TDS reduction and 77% BOD reduction all in 2 h. The treated fibers achieved 35% colour reduction in 30 minutes, 32.5% TDS reduction in 2 h and 82% BOD reduction in 30 minutes. The fibers treated with NaOH performed better in all indices where positive results were achieved except for pH. Luffa cylindrica fibres can be used as effective packing material in a biomass filter for the treatment of paint industry effluent before releasing into the environment based on WHO limits.