Removal of reactive black 5 dye using modified chitosan-pandan adsorbent

There has been increased interest of chitosan as a dye adsorbent. Nonetheless, the chitosan tend to form bonding between their monomer chains that result in a rigid structure which affects its capability for dye adsorption. This is why there are many recent studies on modified chitosan through various modification in order to overcome the limitation. But, most modifications involve chemical additive agents as well as complex procedures that are conducted under strong conditions. Not much research consider low-cost organic materials as modifying agents. The purpose of this work is to investigate the performance of chitosan modified with pandan leaves in the adsorption of reactive black 5 (RB5). Modified chitosan-pandan (MCP) were synthesised by simple wet impregnation using polyphenols from extracted pandan oil under mild condition. MCP was characterised using the scanning electron microscopy, Fourier transform infrared spectroscopy and Brunauer-Emmett-Teller surface area analysis. A batch adsorption was conducted to study the effect of retention time (0-40 min), initial dye concentration (100-1000 mg/L), pH (3-11), temperature (25-80 °C) and dosage of adsorbent (0.01-1.0 g), and to determine the optimum process conditions. Kinetics, isotherm and thermodynamics evaluation were also performed on the adsorption data. The results of MCP adsorption showed outstanding dye removal, with almost 100% under the optimum conditions (30 min, 200 mg/L of RB5, pH 7 and 0.1 g of MCP). The adsorption data fitted well to the pseudo-second order model, indicating the role of chemisorption with the influence of intraparticle diffusion. For isotherm study, the data are best fitted to the Langmuir model (R2 = 0.95) with the maximum adsorption of 115.58 mg/g. A thermodynamics analysis showed that the adsorption was endothermic, occurred spontaneously and feasible. MCP is capable to be regenerated up to 5 times with percentage removal above 50% by only washing with distilled water. In conclusion, a satisfactory performance of MCP in RB5 removal was successfully demonstrated, can be used as a new promising adsorbent for the removal of dyes from textile wastewater

Optimization of phenol adsorption onto biochar from oil palm empty fruit bunch (EFB)

Malaysia, as one of the leading palm oil producers in the world faces problems in disposal of oil palm empty fruit bunch (EFB), which can be converted into various value-added products, including adsorbents. This study investigated the adsorption of phenol from its solution using biochar produced from EFB through carbonization. Response Surface Methodology (RSM) with Box-Behnken design was used to investigate the effects of three parameters (temperature, time and heating rate) during carbonization on phenol removal by the biochar produced. This was followed by process optimization based on statistical analysis. The results indicated that the optimized carbonization conditions were; 500 °C for temperature, 10 °C/min of heating rate and 80 min for reaction timwhich led to 7.57% of phenol removal. SEM revealed coarse and uneven surface of the biochar surface, with small degree of pore development. Comparison between FTIR spectrum of EFB and biochar revealed the loss water and hydroxyl compounds from EFB during carbonization. The lack of oxygenated groups (especially carbonyl groups) on the adsorbent surface as well as limited number of pores were the possible reasons leading to low phenol adsorption by biochar, therefore conversion of the biochar to activated carbon was necessary for higher adsorption performance

Kinetics, thermodynamics, isotherm and regeneration analysis of chitosan modified pandan adsorbent

There has been increased interest of chitosan as a dye adsorbent. Nonetheless, the chitosan tends to form bonding between their monomer chains that result in a rigid structure which affects its capability for adsorption. This is prime reason many recent studies modified chitosan through various modifications. However, most modifications involve chemical additive agents as well as complex procedures that are conducted under strong condition. Not much research consider low-cost organic materials as modifying agent. The purpose of this work is to investigate the performance of chitosan modified with pandan leaves in the adsorption of reactive black 5 (RB5). Modified chitosan-pandan (MCP) adsorbent was synthesized by simple wet impregnation under mild conditions. The MCP was characterized using Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET) surface area analysis. Batch adsorption was conducted to study the effect of retention time (0–60 min), pH (3–11), initial dye concentration (100–1000 mg/L) and temperature (25–80 °C). Kinetics, isotherm, thermodynamics and regeneration evaluation were also performed on the adsorption data. The kinetics data obtained fitted well to the pseudo-second order model, indicating the role of chemisorption with the influence of intraparticle diffusion. For isotherm study, the data is best fitted to the Langmuir model (R2 = 0.91) with maximum adsorption of 169.49 mg/g. Thermodynamics analysis showed that the adsorption is feasible, endothermic and occurred spontaneously. MCP has been regenerated up to 5 times with percentage removal above 50% by washing with distilled water only. In conclusion, natural polyphenols from pandan leaves have been incorporated into chitosan to prepare high-efficiency adsorbent with satisfactory performance in RB5 removal from aqueous media. The MCP is a new promising biodegradable adsorbent for removal of dyes from textile wastewater

Effective removal of anionic textile dyes using adsorbent synthesized from coffee waste

Adsorption of Reactive Black 5 and Congo Red from aqueous solution by coffee waste modified with polyethylenimine was investigated. The removal percentages of both dyes increased with amount of polyethyleneimine in the modified adsorbent. Characterization revealed that polyethyleneimine modification improved the adsorbent surface chemistry, while slight improvement of adsorbent textural properties was also observed. The adsorbent’s excellent performance was demonstrated by high removal percentages towards the anionic dyes in most experimental runs. The modelling result showed that anionic dyes adsorption occurred via monolayer adsorption, and chemisorption was the rate-controlling step. The adsorbent possesses higher maximum adsorption capacity towards Reactive Black 5 (77.52 mg/g) than Congo Red (34.36 mg/g), due to the higher number of functional groups in Reactive Black 5 that interact with the adsorbent. This study reveals the potential of adsorbent derived from coffee waste in textile wastewater treatment. Furthermore, surface chemistry modification is proven as an effective strategy to enhance the performance of biowaste-derived adsorbents

Production and characterization of diesel-like fuel by catalytic upgrading of scrap tire pyrolysis oil using basic catalyst derived from blood cockle shell (Anadara Granosa)

This paper investigates the catalytic upgrading process in overcoming the scrap tire pyrolysis oil (STPO) complexities using a calcium-based catalyst derived from blood cockle shell (Anadara granosa). The calcined blood cockle (CBC) shells were synthesized by varying the temperature of calcination to 800, 900 and 1000 °C. In order to investigate the physico-chemical properties, the STPO was subjected to test method according to ASTM D975. The final distilled oil obtained from catalytic upgrading underwent gas chromatography with mass spectroscopy (GC-MS) analysis, in order to identify its chemical composition. According to the results, CaO material gives the lowest sulphur content (0.08%), compared to Ca(OH)2and Na2CO3catalysts. Among the CBC materials, the highest distilled oil yield is the CBC-1000 catalyst, with a value of 37.7%. The GC-MS analysis of distilled oil obtained from catalytic upgrading using the CBC-1000 catalyst reveals that, predominantly, the hydrocarbon chain is between C8 to C10, which is similar to conventional diesel fuel. The results also infer that there is improvement in STPO in terms of sulphur content (%), yield, and chemical compositions via the catalytic upgrading process. In conclusion, the CBC catalyst derived from blood cockle shell revealed that it has potential in upgrading the STPO to diesel-like fuel