S. Sumathi

Selection of best impregnated palm shell activated carbon (PSAC) for simultaneous removal of SO2 and NOx.

This work examines the impregnated carbon-based sorbents for simultaneous removal of SO(2) and NOx from simulated flue gas. The carbon-based sorbents were prepared using palm shell activated carbon (PSAC) impregnated with several metal oxides (Ni, V, Fe and Ce). The removal of SO(2) and NOx from the simulated flue gas was investigated in a fixed-bed reactor. The results showed that PSAC impregnated with CeO(2) (PSAC-Ce) reported the highest sorption capacity among other impregnated metal oxides for the simultaneous removal of SO(2) and NOx. PSAC-Ce showed the longest breakthrough time of 165 and 115 min for SO(2) and NOx, respectively. The properties of the pure and impregnated PSAC were analyzed by BET, FTIR and XRF. The physical-chemical features of the PSAC-Ce sorbent indicated a catalytic activity in both the sorption of SO(2) and NOx. The formation of both sulfate (SO(4)(2-)) and nitrate (NO(3-)) species on spent PSAC-Ce further prove the catalytic role played by CeO(2).

Adsorption of residual oil from palm oil mill effluent using rubber powder

Abstract - A synthetic rubber powder was used to adsorb the residual oil in palm oil mill effluent (POME). POME is the wastewater produced by thepalm oil industry. It is a colloidal suspension which is95 -96% water, 0.6-0.7% oil and -5% total solids including 4 -4% suspended solids originat2 ing in the mixing of sterilizer condensate, separator sludge and hydrocyclone wastewater. POME contains 4,000 mg dm -3 of oil and grease, which is relatively high compared to the limitof only 50 mg dm -3 set by the Malaysian Department of Environment. A bench-scale study of the adsorption of residual oil in POME using synthetic rubber powderwas conducted using a jar test apparatus. The adsorption process was studied by varying parameters affecting the process. The parameters were adsorbent dosage, mixing speed, mixing time and pH. The optimum values of the parameters were obtained. It was found that almost 88% removal of residual oil was obtained withan adsorbent dosag e of 30 mg dm

Optimization of microporous palm shell activated carbon production for flue gas desulphurization: Experimental and statistical studies

Optimizing the production of microporous activated carbon from waste palm shell was done by applying experimental design methodology. The product, palm shell activated carbon was tested for removal of SO2 gas from flue gas. The activated carbon production was mathematically described as a function of parameters such as flow rate, activation time and activation temperature of carbonization. These parameters were modeled using response surface methodology. The experiments were carried out as a central composite design consisting of 32 experiments. Quadratic models were developed for surface area, total pore volume, and microporosity in term of micropore fraction. The models were used to obtain the optimum process condition for the production of microporous palm shell activated carbon useful for SO2 removal. The optimized palm shell activated carbon with surface area of 973 m(2)/g, total pore volume of 0.78 cc/g and micropore fraction of 70.5% showed an excellent agreement with the amount predicted by the statistical analysis. Palm shell activated carbon with higher surface area and microporosity fraction showed good adsorption affinity for SO2 removal.

Chitosan: A Natural Biopolymer for the Adsorption of Residue Oil from Oily Wastewater

Chitosan, poly-β-(1,4)-2-acetamido-2-deoxy-Đ-glucose (N-deacetylated) was used as an adsorbent to adsorb the excess oil from oily wastewater. Chitosan is a biodegradable cationic biopolymer achieved by the extensive deacetylation of chitin obtained from prawn shell waste. Palm oil mill effluent (POME) is one of the major problematic oily wastewaters in Malaysia. Preliminary analysis showed that POME contains ca. 2000 mg/l residue oil. A bench-scale study of the adsorption by chitosan of residue oil in POME was conducted using a jar-test apparatus. Effects of experimental parameters such as the dosage of chitosan in powder and flake form, contact time, mixing rate, settling time and pH were studied in order to obtain the optimum conditions for the adsorption of residue oil from POME. The results obtained showed that chitosan powder, at a dosage of 0.5 g/l and employing a contact time of 15 min, a mixing rate of 100 rpm, sedimentation for 30 min and a pH value of 5.0, provided the most suitable conditions for the removal of residue oil from POME. The removal efficiencies obtained were ca. 97–99%. FT-IR spectra and SEM micrographs of chitosan before and after adsorption were presented to prove that the residue oil had been adsorbed by chitosan.