P. N. Palanisamy

Polymer Composite—A Potential Biomaterial for the Removal of Reactive Dye

Poly Pyrrle saw dust composite was prepared by reinforcement of natural wood saw dust (obtained from Euphorbia Tirucalli L wood) and Poly Pyrrole matrix phase. The present study investigates the adsorption behaviour of Poly Pyrrole Saw dust Composite towards reactive dye. The batch adsorption studies were carried out by varying solution pH, initial dye concentration, contact time and temperature. The kinetic study showed that adsorption of Reactive Red by PPC was best represented by pseudo-second order kinetics with ion exchange adsorption. The equilibrium data were analyzed by Freundlich and Langmuir isotherm model. The equilibrium isotherm data were fitted well with Langmuir isotherm model. The maximum monolayer adsorption capacities calculated by Langmuir model were 204.08 mg/g for Reactive Red at 303 K. The thermodynamic parameters suggest the spontaneous, endothermic nature of ion exchange adsorption with weak Vader walls force of attraction. Activation energy for the adsorption of Reactive by Poly Pyrrole Composite was 11.6387 kJ/mole, Isosteric Heat of adsorption was 48.5454 kJ/mole also supported the ion exchange adsorption process in which forces of attraction between dye molecules and PPC is weak.

Novel Activated Carbons from Agricultural Wastes and their Characterization

Solid waste disposal has become a major problem in India, Either it has to be disposed safely or used for the recovery of valuable materials as agricultural wastes like turmeric waste, ferronia shell waste, jatropha curcus seed shell waste, delonix shell waste and ipomea carnia stem. Therefore these wastes have been explored for the preparation of activated carbon employing various techniques. Activated carbons prepared from agricultural solid wastes by chemical activation processes shows excellent improvement in the surface characteristics. Their characterization studies such as bulk density, moisture content, ash content, fixed carbon content, matter soluble in water, matter soluble in acid, pH, decolourising power, phenol number, ion exchange capacity, ion content and surface area have been carried out to assess the suitability of these carbons as absorbents in the water and wastewater. For anionic dyes (reactive, direct, acid) a close relationship between the surface area and surface chemical groups of the modified activated carbon and percentage of dye removal by adsorption can be observed. Cationic dyes large amount of surface chemical groups present in the sample (mainly carboxylic, anhydrides, lactones and phenols etc.) are good anchoring sites for adsorption. The present study reveals the recovery of valuable adsorbents from readily and cheaply available agriculture wastes.

Orthophosphoric Acid Activated Babul Seed Carbon as an Adsorbent for the Removal of Methylene Blue

An Experimental and theoretical study has been conducted on the adsorption of methylene blue dye using activated carbon prepared from babul seed by chemical activation with orthophosphoric acid. BET surface area of the activated carbon was determined as 1060 m2/g. Adsorption kinetics, equilibrium and thermodynamics were investigated as a function of initial dye concentration, temperature and pH. First order Lagergren, pseudo-second order and Elovich kinetic models were used to test the adsorption kinetics. Results were analyzed by the Langmuir, Freundlich and Temkin isotherm models. Based on regression coefficient, the equilibrium data found fitted well to the Langmuir equilibrium model than other models. The characteristics of the prepared activated carbon were found comparable to the commercial activated carbon. It is found that the babul seed activated carbon is very effective for the removal of colouring matter.

Comparative Studies of the Adsorption of Direct Dye on Activated Carbon and Conducting Polymer Composite

This study analyses the feasibility of removing Direct Blue 71 from aqueous solution by different adsorbents such as activated carbon (TPAC) and Poly pyrrole polymer composite (PPC) prepared from Thevetia Peruviana. Batch mode adsorption was performed to investigate the adsorption capacities of these adsorbents by varying initial dye concentration, temperature, agitation time and pH. The performance of TPAC was compared with PPC. Among the adsorbents, PPC had more adsorption capacity (88.24%) than TPAC (58.82%) at an initial concentration of 50 mg/L and at 30°C. The experimental data best fitted with pseudo second order kinetic model. The adsorption data fitted well for Langmuir adsorption isotherm. Thermodynamic parameters for the adsorbents were also evaluated. The carbon embedded in conducting polymers matrix show better adsorptive properties than activated carbon.

Application of Polyaniline Nano Composite for the Adsorption of Acid Dye from Aqueous Solutions

In this research, Polyaniline coated sawdust (Polyaniline nano composite) was synthesized via direct chemical polymerization and used as an adsorbent for the removal of acid dye (Acid Violet 49) from aqueous solutions. The effect of some important parameters such as pH, initial concentration of dye, contact time and temperature on the removal efficiency was investigated in batch adsorption system. The adsorption capacity of PAC was high (96.84 %) at a pH of 3-4. The experimental data fitted well for pseudo second order model. Langmuir model is more appropriate to explain the nature of adsorption with high correlation coefficient. The Energy of activation from arrehenius plot suggested that the adsorption of AV49 onto PAC involves physisorption mechanism.

Assessment of Ground Water Quality in and around Gobichettipalayam Town Erode District, Tamilnadu

Ground water samples collected from different localities in and around Gobichettipalayam town, Erode District, Tamil Nadu were analyzed for their physico- chemical characteristics. This analysis result was compared with the WHO a ICMR standards of drinking water quality parameters with the following water quality parameters namely pH, Electrical conductivity, CN-, Cl-, SO42-, Na

An Assessment of the Quality of Groundwater in a Textile Dyeing Industrial Area in Erode City, Tamilnadu, India

Groundwater samples were collected in Erode city, Tamilnadu, from an area having large number of textile dyeing units. Though people residing in this area use river water supplied by local bodies as their major source for drinking, groundwater is also used as complementary source. The samples collected were subjected to systematic analysis using the standard methods and procedures. The values obtained for different physicochemical parameters were compared with the standard values given by ISI/ WHO. Variations in many physicochemical parameters were observed for most of the samples when compared to the standard values. More than half of the samples collected had their EC, TDS, total hardness, calcium, magnesium, sulphate and chloride exceeding their acceptable limits. This attempt has been made to determine the quality of groundwater in the study area confirms the deterioration of groundwater quality in the area and calls for some effective measures to be taken urgently to minimize the adverse impacts that may occur due to the contamination of groundwater.

Adsorptive removal of Direct Red-7 from aqueous solution by uncalcined and calcined zinc aluminium carbonate layered double hydroxide — kinetics and isotherm study

In this paper, two materials, namely zinc aluminium carbonate layered double hydroxide (ZAC-LDH) and calcined LDH (CZA-LDH) are prepared and employed for the removal of Direct Red-7 (DR-7) dye from aqueous solution. Batch mode studies are carried out for the removal of DR-7 using different parameters such as initial dye concentration, adsorbent dosage, contact time, temperature and pH. The adsorption kinetics is studied using classic equations of pseudo-first-order, pseudo-second-order and intraparticle diffusion models. The pseudo-second-order kinetic model fits well with the high correlation coefficient for the removal of DR-7 by both ZAC-LDH and CZA-LDH. The equilibrium data are examined using Langmuir and Freundlich isotherm models. The maximum adsorption capacity for the removal of DR-7 onto CZA-LDH is found to be 666.67 mg/g which is higher than the ZAC-LDH (357.14 mg/g) at 30°C. X-ray diffraction and Fourier transform infrared spectroscopy analysis also have been carried out to confirm the interaction of dye molecule onto the adsorbents. The evaluated thermodynamic parameters of ΔG° and ΔH° indicate that the adsorption process is spontaneous and endothermic in nature. The ZAC-LDH and CZA-LDH are thermally regenerated and reused for the dye removal of DR-7 from aqueous solution. The enhanced dye removal of DR-7 by CZA-LDH proves that the CZA-LDH is a more suitable adsorbent for the removal of DR-7 compared with ZAC-LDH from aqueous solution.

Enhanced Adsorptive Removal of Anionic Dyes by using Calcined Zinc Aluminium Layered Double Hydroxide CZA-LDH from Aqueous Solution

Removal of anionic dyes namely Acid Violet-17(AV-17) and Direct Red-7 (DR-7) from aqueous solution were investigated by calcined zinc aluminium layered double hydroxide (CZA-LDH). Batch adsorption studies were carried out by varying the parameters such as contact time, adsorbent dose, initial dye concentration, temperature and pH. The equilibrium adsorption capacity of AV-17 (adsorbent dose 0.5g/L) and DR-7(adsorbent dose 0.125g/L) dyes were increased from 48.08 mg/g to 172.55 mg/g and 200 mg/g to 683.33 mg/g respectively with increase of initial dye concentration from 25 mg/L to 100 mg/L at 30°C. Similarly the percentage of dye removal was decreased from 100% to 85.42% and 96.15% to 86.27% for DR-7 and AV-17 respectively with increase of initial dye concentration from 25 mg/L to 100 mg/L. The adsorption kinetics of both the anionic dyes AV-17 and DR- 7 by CZA-LDH followed the pseudo second order kinetic model with high correlation coefficient values (R2) than the pseudo first order. The experimental data were well fitted with Freundlich isotherm model rather than Langmuir model. The adsorption equilibrium was more favourable at acidic pH than alkaline pH for both dyes. The thermodynamic parameters like ΔGo and ΔHo calculated for AV-17 and DR-7 revealed that the adsorption process is spontaneous and endothermic in nature. The XRD pattern of CZA-LDH before and after the adsorption of AV-17 and DR-7 proved the intercalation of anionic dyes between the layers with memory effect by the reconstruction of its original layered structure. This was further evidenced by slight increase in the interlayer distance. The adsorption processes were further supported by Langmuir dimensionless separation factor RL and n value of the Freundlich Equation. Thermal regeneration and reusability of CZA-LDH was performed for the removal of AV-17 & DR-7. The recycling and reusability for the dye removal up to second cycle for both anionic dyes were remarkable and suggested that the CZA-LDH was an effective adsorbent for the removal of anionic dyes AV-17 and DR-7 from aqueous solution.