The biosorption of methyl violet and methylene blue onto modified pine cone powder was studied. Single and binary component systems studies were carried out for the biosorption of methyl violet and methylene blue onto raw, Fenton treated and acrylic acid grafted pine cone powder. Various experimental parameters were studied including initial dye concentration (200-900 mg/dm3), contact time, solution pH (4-12), mass of adsorbent (0.05-0.30g) and temperature (25-45 °C). Pseudo-first order and pseudo-second order equations were used to analyze the kinetic data. It was found that the data follow the pseudo -second order kinetic model for all temperature studied. The experimental data were analyzed using Langmuir and Freudlich isotherm model. The biosorption of methyl violet and methylene blue showed a better fit to Langmuir isotherm which properly describes the experimental data and that the sample surfaces are homogeneous. Various thermodynamic parameters, such as Gibbs energy (ΔG*), enthalpy change (ΔH*) and entropy change (ΔS*), were calculated which indicated the present system was spontaneous and exothermic process for methyl violet and methylene blue. It was found that enthalpy and entropy of acrylic acid grafted pine cone was higher as compared to raw and Fenton‘s reagent for methyl violet and methylene blue. Raw, Fenton treated and acrylic acid pine cone powder were characterized with Fourier transform infrared spectroscopy (FTIR), Ultraviolet-visible spectroscopy (UV-VIS), Thermogravimetic analysis (TGA/DTA), X-ray Diffraction (XRD) and Brauner, Emmett and Teller (BET). The following parameters were used to determine the surface properties of the grafted pine cone: change in H+ concentration and oxidation reduction potential (ORP), surface negative charge, bulk density and acid number measurements. The FTIR analysis confirmed the presence of the organic compounds on the raw, Fenton treated and acrylic acid grafted pine cone powder. The UV/VIS determined the percentage removal of dyes from aqueous solution in single and binary component systems by comparing the raw, Fenton treated and Acrylic acid grafted pine cone powder. Thermo gravimetric analysis confirmed the reactions which occur at the molecular level of the raw, Raw + KMnO4 and Fenton treated + KMnO4 pine cone powder materials. vi | P a g e The second order derivative spectroscopy (SODS) was a suitable method for the analysis of the study of cationic dyes in binary solution. To determine the unknown concentrations of methyl violet and methylene blue dyes in binary solution using SODS, maximum wavelengths 561.8 nm and 623.1 nm were obtained. It was found that the percentage removal was higher for acrylic acid grafted pine cone than Fenton‘s treated and raw pine cone and treated samples adsorbed more methyl violet that methylene blue.

The relationship between clone and cone color in western white pine, Pinus monticola Douglas, to attack by the mountain pine cone beetle, Conophthorus monticolae Hopkins, was studied in the Sandpoint Seed Orchard, Idaho. A positive relationship was shown to exist during a 5 year field evaluation. Cone beetles were found to prefer dark colored cones and to attack certain clones at a higher rate than others. Laboratory dissections did not indicate that cone color affected oviposition, brood development or brood mortality. Olfactometer experiments demonstrated that olfactory stimuli are involved in the cone beetle attack sequence. Visual cues relating to cone color may be involved in the initial long range host orientation of attacking beetles.

M. Tech. (Department of Chemistry, Faculty of Applied and Computer Sciences) -- Vaal University of Technology / The widespread use of phenols and phenolic derivatives in industrial applications has resulted in their discharge as part of industrial wastewater. These chemicals are toxic and need to be removed from the aqueous environment. Amongst the available pollutant removal technologies, adsorption has been widely used due to its simplicity, ease of operation, cost-effectiveness and ability to sequester pollutants at very low concentrations. Different adsorbents have been applied for removal of phenols and their derivatives. Use of agricultural waste as adsorbents seems to offer a much cheaper alternative in pollutant removal. This study examines the synthesis of a hydrophobic biomaterial composite by cross-linking of Fenton treated pine cone and applying the prepared adsorbent for 2-nitrophenol removal from aqueous solution. Pine cone biomass, in its raw and modified forms was tested for its ability to remove 2-nitrophenol from simulated industrial wastewater. The experimental procedure is divided into two main parts: (1) pine cone modification using Fenton’s reagent and 1.6-hexamethylene diisocyanate and (2) application of the prepared hydrophobic adsorbent for 2-nitrophenol removal from wastewater. Fenton’s reagent was used to remove pigments, extractives and other soluble organic compounds from the raw pine. FTIR spectroscopy showed an increase in magnitude of oxygenated surface groups which resulted in a decrease in pHpzc. The effect of Fenton treatment on further modification of the pine biomass via cross-linking using 1.6-hexamethylene diisocyanate was investigated. Optimum reaction variables for the cross-linking using dibutyltin dilaurate as catalyst under an inert nitrogen gas atmosphere in anhydrous hexane solvent were determined using FTIR spectroscopy. Success of the cross-linking procedure was confirmed by use of analytical techniques (XRD, TGA, SEM, EDX and BET surface area) and weight percent gain calculations. Pine and modified pine biomass were tested for their ability to sequester 2-nitrophenol via batch adsorption technique. The effect of pine modification on affinity for the biosorbate was investigated. The mechanism of the adsorption process was determined via use of kinetic, diffusion and equilibrium isotherm models. Two error functions (coefficient of determination and percent variable error) were employed to substantiate the model showing a good fit to the experimental adsorption data. The experimental adsorption kinetic data was fit to the pseudo-first-order and pseudo-second-order kinetic models. Due to the large size of the pollutant molecules diffusion process analysis was also conducted. The effect of pine modification on kinetic and diffusion parameters was determined. The experimental equilibrium adsorption data was fit to the Freundlich, Redlich-Peterson and Hill isotherm models. The initial shapes of the adsorption isotherms for 2-nitrophenol adsorption onto pine and modified pine biomass determined the type of equilibrium isotherm models to fit the experimental data to. Thermodynamic parameters were calculated to determine the spontaneity, feasibility and energy changes associated with the adsorption process. The degree of disorder at the solid/liquid interface after the adsorption was determined. The effect of temperature on the adsorption process was used to show whether the adsorption is physical or chemical. The effect of pine modification on equilibrium isotherm parameters was determined. The study is divided into seven chapters: Chapter 1: The chapter covers the introduction, problem statement, aim and objectives of the research. It gives an insight into the research project. Chapter 2: The literature review of pollutants in industrial wastewater and methods of their removal is dealt with in this chapter. Adsorption is introduced as an alternative technique for pollutant removal from aqueous systems. An in-depth review of various adsorbents (including pine cone), their merits and limitations are also discussed together with methods of modifying and use of modified adsorbents. Equilibrium, kinetic and thermodynamic models used to treat adsorption experimental data are presented. Chapter 3: The experimental procedures on the synthesis, characterization and application of the hydrophobic biosorbent in the removal of 2-nitrophenol from aqueous solution are presented. Kinetic and equilibrium experiments are described in detail. Chapter 4: It describes the first part of the results and discussions. The chapter focuses on optimization of reaction variables and characterization (using various analytical techniques) of the hydrophobic biomaterial composite. Chapter 5 The chapter discusses the second part of the results. It focuses on magnitude of surface charge, pHpzc and kinetic studies. Fitting of the adsorption experimental data to kinetic and diffusion models is presented together with the error functions. Chapter 6 The chapter discusses part three of the results on equilibrium studies. The adsorption experimental data is fitted to equilibrium isotherm equations and error determination is presented. Thermodynamic parameters are calculated and interpreted. Chapter 7: Conclusion and recommendations are presented. The optimum reaction variables for cross-linking of Raw and Fenton treated pine cone were determined using FTIR analysis and found to be: 0.2 g pine biomass, 3.5 cm3 1.6-hexamethylene diisocyanate cross-linker, 50 cm3 anhydrous hexane solvent, 1.5 cm3 dibutyltin dilaurate catalyst, temperature of 50 °C and a reaction time of 4 hours. The pine surface showed an increase in phenolic, lactonic and carboxylic acid groups due to the modification. The pHpzc showed a decrease due to modification of the pine cone biomass. The pHpzc values for the pine and modified pine cone biomass were found to be: Raw = 7.49, Raw-HMDI modified = 6.68, Fenton treated pine = 5.40 and Fenton-HMDI modified = 6.12. The optimum pH for the adsorption of 2-nitrophenol onto raw pine and modified pine cone biomass was determined to be 6. The optimum adsorbent dosage was determined as 1.5 g/dm3. The adsorption kinetics show a good fit with the pseudo-second-order model. This suggests that surface adsorption is the controlling step in the adsorption of 2-nitrophenol onto pine cone biomass. The analysis of diffusion processes showed that the initial rapid stage during the adsorption is due to external mass transfer processes. The adsorption experimental data also showed that pore diffusion was rate-limiting amongst the diffusion processes. Pine modification using Fenton’s reagent and 1.6-hexamethylene diisocyanate increased magnitude of kinetic and diffusion parameters. Experimental data for 2-nitrophenol adsorption onto pine and modified pine cone biomass showed better correlation with the Redlich-Peterson and Hill isotherm models and poor correlation with the Freundlich isotherm model. This suggests that the mechanism does not show complete multilayer coverage with cooperative phenomena between adsorbate molecules. Thermodynamic parameters showed that the adsorption is feasible, spontaneous, and exothermic and results in a decrease in degree of disorder at the solid/liquid interface. An increase in temperature resulted in a decrease in adsorption capacity showing that the adsorption is physical. Pine modification using Fenton’s reagent and 1.6-hexamethylene diisocyanate increased magnitude of kinetic, diffusion and isotherm parameters. The kinetic and equilibrium results show that the adsorption of 2-nitrophenol onto pine cone biomass follows the order: Fenton treated-HMDI > Fenton treated > Raw-HMDI > Raw. Hence, it can be concluded that Fenton treatment and HMDI cross-linking modification did increase the adsorptive capabilities of the pine cone biomass. / VUT Research Directorate

M. Tech. (Department of Chemical Engineering, Faculty of Engineering and Technology), Vaal University of Technology / Fenton oxidation is classified into two processes, homogeneous and heterogeneous. Homogeneous Fenton oxidation process, have been shown to be efficient in the degradation of organic pollutants. However, it was shown to have limitations which can be addressed by the heterogeneous Fenton oxidation. Despite the high efficiency of the heterogeneous Fenton oxidation process in the degradation of recalcitrant organic pollutants, the currents synthesis trends of the heterogeneous Fenton catalyst have been proven to be time and energy constraining, since it involves the multi-step were the activated carbon have to be prepared first then co-precipitate the iron oxide on the activated carbon. However, as much as the heterogeneous Fenton catalyst has been proven to have high catalytic activity towards degradation of organic pollutants, these catalysts have some limitations, such limitations include metal ions being leached from the catalyst support into the treated water causing catalyst deactivation and a secondary pollution to the treated water. In this thesis, these catalysts have been applied in the degradation of recalcitrant organic pollutants such as methylene blue and phenols. This study focuses on the single step synthesis of iron oxide nanoparticles supported on activated carbon, were carbonaceous material is impregnated with iron salt then pyrolysed via microwave heating. Microwave power and the amount of iron salt were optimized. The prepared activated carbon-iron oxide composites were applied to the degradation of 2-nitrophenol (2-NP) and methylene blue (MB). Methylene blue was used as a model compound due to the fact that it is easier to monitor the degradation process with UV-Vis as compared to 2-nitrophenol . 2-nitrophenol the additional step for the adjustment of pH is required since nitrophenols are colorless in color at lower pH. The characterization showed that the microwave power and the amount of the iron precursor have an influence on the porosity and surface functional groups of the activated carbon. Further it was vi observed that microwave power and iron precursor influnces the amount of iron oxide formed on the surface of the support. It was also observed that the activated carbon-iron oxide composite have the catalytic effects on the Fenton oxidation process of MB and 2-NP. The parameters such as H2O2, pH, catalyst dose, initial concentration, temperature affect the degradation of both MB and 2-NP. Kinetics studies showed that Fenton is a surface driven reaction since the results fitted the pseudo first order model. The thermodynamics parameters also showed that the reaction is endothermic, spontaneous and is randomized. This implies that the reaction of the degradation of MB and 2-NP is feasible and the catalysts prepared have high catalytic activity. MB and 2-NP were degraded to smaller organic molecules (carboxylic acids). The stability of the catalyst observed to decrease as the number of cycles increased, this is due to the leaching of iron ions from the support material. Hence it was concluded that the activated carbon-iron oxide composite was successfully synthesized and had the high catalytic activity for the degradation of MB and 2-NP.