P. Ganesan

Comparative kinetic study of functionalized carbon nanotubes and magnetic biochar for removal of Cd2+ ions from wastewater

We did a comparative study between functionalized multiwall carbon nanotube (FMWCNTs), and magnetic biochar was carried out to determine the most efficient adsorbent to be employed in the Cd2+ ion removal. We optimized parameters such as agitation speed, contact time, pH and adsorbent dosage using design expert vrsion 6.08. The statistical analysis reveals that optimized condition for highest removal of Cd2+ are at pH 5.0, with dosage 1.0 g, agitation speed and contact time of 100 rpm and 90 minutes, respectively. For the initial concentration of 10mg/l, the removal efficiency of Cd2+ using FMWCNTs was 90% and and 82% of magnetic biochar. The maximum Cd2+ adsorption capacities of both FMWCNTs and magnetic biochar were calculated: 83.33mg/g and 62.5mg/g. The Langmuir and Freundlich constants for FMWCNTs were 0.056 L/mg and 13.613 L/mg, while 0.098 L/mg and 25.204 L/mg for magnetic biochar. The statistical analysis proved that FMWCNTs have better adsorption capacity compared to magnetic biochar and both models obeyed the pseudo-second-order.

Hydrothermal carbonization of oil palm shell

Palm shell is one of the most plentiful wastes of the palm oil mill industry. This study identifies the capability of hydrothermal carbonization process (HTC) to convert palm shell into high energy hydrochar. The influence of reaction time and reaction temperature of the HTC process was investigated. The process parameters selected were temperature 200 °C to 240 °C, time 10 to 60min, and water to biomass ratio was fixed at 10 : 1 by weight %. Fourier transform infrared (FTIR), elemental, proximate, Burner Emmett and Teller (BET), thermo-gravimetric (TGA) analyses were performed to characterize the product and the feed. The heating value (HHV) was increased from 12.24 MJ/ kg (raw palm shell) to 22.11 MJ/kg (hydrochar produced at 240 °C and 60 min). The hydrochar yield exhibited a higher degree inverse proportionality with temperature and reaction time. Elemental analysis revealed an increase in carbon percentage and a proportional decrease in hydrogen and oxygen contents which caused higher value of HHV. The dehydration and decarboxylation reactions take place at higher temperatures during HTC resulting in the increase of carbon and decrease in oxygen values of hydrochar. The FESEM results reveal that the structure of raw palm shell was decomposed by HTC process. The pores on the surface of hydrochar increased as compared to the raw palm shell.

Adsorption of chromium (VI) on functionalized and non-functionalized carbon nanotubes

We did a comparative study on the adsorption capacity of Cr (VI) between functionalized carbon nanotubes (CNTs) and non-functionalized CNTs. The statistical analysis reveals that the optimum conditions for the highest removal of Cr (VI) are at pH 9, with dosage 0.1 gram, agitation speed and time of 120 rpm and 120 minutes, respectively. For the initial concentration of 1.0 mg/l, the removal efficiency of Cr (VI) using functionalized CNTs was 87.6% and 83% of non-functionalized CNTs. The maximum adsorption capacities of functionalized and non-functionalized CNTs were 2.517 and 2.49 mg/g, respectively. Langmuir and Freundlich models were adopted to study the adsorption isotherm, which provided a KL and KF value of 1.217 L/mg and 18.14 mg1−nLn/g functionalized CNT, while 2.365 L/mg and 2.307 mg1−nLn/g for non-functionalized CNTs. This result proves that functionalized CNTs are a better adsorbent with a higher adsorption capacity compared with the non-functionalized CNTs.

Removal of Methylene Blue and Orange-G from Waste Water Using Magnetic Biochar

The study on the removal of methylene blue (MB) and orange-G dyes using magnetic biochar derived from the empty fruit bunch (EFB) was carried out. Process parameters such as pH, adsorbent dosage, agitation speed and contact time were optimized using Design-Expert Software v.6.0.8. The statistical analysis reveals that the optimum conditions for the maximum adsorption of MB are at pH 2 and pH 10, dosage 1.0 g, and agitation speed and contact time of 125 rpm and 120 min respectively. While for orange-G, at pH 2, dosage 1.0 g, and agitation speed and contact time of 125 rpm and 120 min respectively. The maximum adsorption capacity of 31.25 mg/g and 32.36 mg/g for MB and orange-G respectively. The adsorption kinetic for both dyes obeyed pseudo-second order.