M. Hakkı Alma

Removal of methylene blue from aqueous solution using cotton stalk, cotton waste and cotton dust.

In this study, cotton stalk (CS), cotton waste (CW) and cotton dust (CD) was used as sorbents to remove methylene blue (MB) from aqueous solution by batch sorption technique. Effects of initial dye concentration, solution pH, solution temperature and sorbent dose on sorption were studied. It was seen that the removal of methylene blue increased with increasing initial dye concentration (from 25 to 100 mg/l), solution pH (from 5 to 10), solution temperature (from 20 to 50°C) and sorbent dose (from 0.25 to 1.50 g/50 ml). The maximum dye removal was reached at 90 min. Sorption isotherms were analyzed by Langmuir and Freundlich models at different temperatures of 20, 30, 40 and 50°C, and the results were discussed in detail. Moreover, the thermodynamics of sorption were also studied. It was found that the values of standard free energy (ΔG°) were positive for cotton stalk and negative for cotton waste and cotton dust. The values of standard enthalpy (ΔH°) and entropy (ΔS°) were found to be positive, and the obtained results were interpreted in detail. The results of this study showed that cotton stalk, cotton waste and cotton dust could be employed as effective and low-cost materials for the removal of dyes from aqueous solution.

Antibacterial and Antifungal Activities of Turkish Medicinal Plants

In this study, the antibacterial and antifungal activities of Rhus coriaria L. (Anacardiaceae), Stachys annua (L.) subsp. annua Ic., Stachys pumilia Banks & Sol., Laurus nobilis L. (Lauraceae), Allium neapolitanum Lyr. (Liliaceae), Salvia viridis L. (Lamiaceae), and Nicotina rustica (Solanaceae) species were investigated. The microbial effects of these plants were tested by a disk diffusion method using Bacillus megaterium DSM 32, Bacillus brevis FMC 3, Bacillus subtilis IMG 22, Bacillus cereus FMC 19, Escherichia coli DM, Enterobacter aerogenes CCM 2531, Pseudomonas aeruginosa DSM 50071, Staphylococcus aureus Cowan 1, Listeria monocytogenes Scott A and Micrococcus luteus LA 2971, Candida tropicalis and Candida albicans CCM 314. The results showed that the fruit extract of R. coriaria had the strongest antimicrobial effect with an inhibition zone of 35–51 mm against all the bacteria used, while S. viridis demonstrated the weakest antibacterial effect, inhibiting only the development of S. aureus, with an inhibition zone of 11 mm. A. neapolitanum, L. nobilis and N. rustica extracts were effective only with some yeasts. The growth of S. aureus was inhibited by all the plant extracts except for S. annua subsp. annua, having an inhibition zone ranging from 7–8 mm. With the exception of B. subtilis IMG 22, L. monocytogenes Scott A and M. luteus LA 2971, the growth of the other bacteria was inhibited by all the extracts. Except for the fruit extracts of R. coriaria and A. neapolitanum, all additional extracts of generated inhibition zones smaller than those generated by several reference antibiotics.

Antimicrobial activities of several parts of Pinus brutia, Juniperus oxycedrus, Abies cilicia, Cedrus libani and Pinus nigra.

In this study, the antimicrobial activities of several parts of various trees grown in the Kahramanmaraş region of Turkey were investigated by the disc diffusion method. Chloroform, acetone and methanol extracts of leaves, resins, barks, cones and fruits of Pinus brutia Ten., Juniperus oxycedrus L., Abies cilicia Ant. & Kotschy Carr., Cedrus libani A. Rich. and Pinus nigra Arn. were prepared and tested against Bacillus megaterium DSM 32, Bacillus subtilis IMG 22, Bacillus cereus FMC 19, Escherichia coli DM, Klebsiella pneumoniae FMC 3, Enterobacter aerogenes CCM 2531, Staphylococcus aureus Cowan 1, Mycobacterium smegmatis RUT, Proteus vulgaris FMC 1, Listeria monocytogenes Scoot A, Pseudomonas aeruginosa DSM 5007, Candida albicans CCM 314, Candida tropicalis MDC 86 and Penicillium italicum K.

Thermal stability of novolak-type thermosettings made by the condensation of bark and phenol

Abstract The barks of calabrian pine ( Pinus brutia ) and Anatolia chestnut ( Cestanea sativa ) tree species have been condensed with phenol in the presence of sulfuric acid as a catalyst at a temperature of 130°C for 1 h. The phenolated bark species obtained was cured with hexamethylenetetramine (HMTA) at 190°C for 5 min and then, some thermal properties [thermogravimetric weight changes and glass transition point ( T g )] of the cured phenolated barks were investigated by using thermal gravimetric analysis (TGA) and differential scanning calorimetric (DSC) methods as a function of the catalyst concentrations. The results showed that themogravimetric weight losses and glass transition points ( T g ) of the cured phenolated bark decreased with increasing catalyst concentration. The thermogravimetric weight loss of the cured phenolated barks was found to be comparable to those of cured commercial novolak resin and phenolated wood. Furthermore, the T g s of the phenolated bark samples were found to increase with increasing catalyst concentration and to be obviously lower than those of commercial novolak resin.

Use of Aspergillus wentii for biosorption of methylene blue from aqueous solution

In this study, Aspergillus wentii was used as a biosorbent for the adsorption of methylene blue from aqueous solution. The effects of contact time, initial dye concentration, solution pH and temperature on biosorption were investigated. The contact time required (that is, the equilibrium time) for maximum dye biosorption was found to be 120 min. The amount of the dye biosorbed increased with increasing initial dye concentrations and solution pH, while it was decreasing with an increase in temperature. Percent biosorption was changed between 14.86 and 85.04 under all conditions studied. Desorption studies were performed by changing of the value pH among 3 - 10. Desorption was considerably affected by lower pH. The maximum percentage of desorption was found to be 29.51 at pH 3. Biosorption isotherm from equilibrium values followed Freundlich model.

The application of pyrolysis-molecular beam mass spectrometry for characterization of bark phenolysis products

Barks from four common Mediterranean trees subjected to phenolysis under acidic conditions at moderate temperature (130°C or 150°C) were evaluated with pyrolysis-molecular beam mass spectrometer (py-MBMS). The results indicated that both concentration of acid catalyst and the phenolysis temperature have an impact on the chemical composition of both the isolated oils and the solid residue, with the acid concentration having the greatest influence. The primary phenolysis reaction products included phenolics and furans. As expected, at higher acid concentrations the phenolysis products contained less carbohydrate and included more phenolic fragments. These phenolysis oils should be useful as feedstocks for the production of phenol formaldehyde resins. The py-MBMS method was found to be an effective and convenient method to understand bark phenolysis.

Conversion of barks of several tree species into bakelite-like thermosetting materials by their phenolysis

In this study, barks of several tree species, such as Calabrian pine, cedar, eucalyptus, acacia, Anatolia chestnut and Turk oak, were phenolated by using sulfuric acid as a catalyst at a temperature of 130°C for 1 h. The phenolated barks obtained were cured with hexamethylenetetramine (HMTA). Then, the mechanical properties (static flexural strength) of the phenolated bark-based molding materials were evaluated. The results showed that the barks of various tree species were easily phenolated in the presence of sulfuric acid, and the phenolated bark could be molded like a commercial novolak resin. It was also found that barks with small amounts of ash were effectively phenolated in comparison to barks with large amounts of ash. On the other hand, the reaction type of the bark phenolysis could be classified as exothermic as in the production of phenol-formaldehyde resin. Eventually, it was determined that the flexural strength of the whole phenolated bark-based moldings studied, excluding phenolated acacia bark, was similar to that of the commercial novolak resin-based moldings.

Engine Performance and Exhaust Emission Tests of Sulfate Turpentine and No:2 Diesel Fuel Blend

Abstract: Environmentally friendly, biobased fuel additives become more important when environmental concerns all around the world are considered. In this study, sulfate turpentine is investigated as a candidate diesel fuel additive. Engine performance tests were conducted on a 53 kW, 4000 rpm Peugeot XD 3P 157 type diesel engine for 3:97 turpentine and No:2 diesel fuel blend and similar results to No:2 diesel fuel were obtained. Significant reduction in exhaust emissions were observed as a result of using turpentine and No:2 diesel fuel blend.

Mechanical, thermal, morphological properties and decay resistance of filled hazelnut husk polymer composites

Four different formulations of natural fiber-polymer composites were fabricated from mixtures of hazelnut (Corylus avellana) husk flour (HHF), polypropylene (PP) and high density polyethylene (HDPE). Variables examined included polymer and coupling agent types. All formulations were compression molded in a hot press for 3 minutes at 175 0C. The resulted specimens were tested for mechanical properties according to ASTM D-790 and ASTM D-638. In addition, scanning electron microscopy (SEM), thermogravimetry (TG) and Differential Scanning Calorimetry (DSC) analysis were performed to characterize rheological properties of the fabricated composite. Furthermore, decay tests were performed to determine degradation of hazelnut husk polymer matrices. Hazelnut husk polymer composites had high mechanical properties for the tested formulations. The thermal studies showed that incorporation of hazelnut husk into the polymer matrices used did not adversely affect the composite. The HDPE+50% wood + 3% MAPE (HHF2) formulation showed the highest natural durability with only 3,47% and 4,60% mass losses against Trametes versicolor and Postia plecenta, respectively, while Scots pine solid controls experienced around 32% mass loss under the same exposure condition.

Enrichment of the Glycyrrhizic Acid from Licorice Roots (Glycyrrhiza glabra L.) by Isoelectric Focused Adsorptive Bubble Chromatography.

The main aim of this study was to enrich glycyrrhizic acid ammonium salt known as one of the main compounds of licorice roots (Glycyrrhiza glabra L.) by isoelectric focused adsorptive bubble separation technique with different foaming agents. In the experiments, four bubble separation parameters were used with β-lactoglobulin, albumin bovine, and starch (soluble) preferred as foaming agents and without additives. The enrichment of glycyrrhizic acid ammonium salt into the foam was influenced by different additive substances. The results showed that highest enrichment values were obtained from β-lactoglobulin as much as 368.3 times. The lowest enrichment values (5.9 times) were determined for the application without additive. After enrichment, each experiment of glycyrrhizic acid ammonium salt confirmed that these substances could be quantitatively enriched into the collection vessel with isoelectric focused adsorptive bubble separation technique. The transfer of glycyrrhizic acid ammonium salt into the foam from standard solution in the presence of additive was more efficient than aqueous licorice extract.