Removal of phenol from industrial wastewaters using lignitic coals

Thesis (Master)--Izmir Institute of Technology, Environmental Engineering, Izmir, 2004Includes bibliographical references (leaves: 66-70)Text in English; Abstract: Turkish and Englishxi, 79 leavesPhenol adsorption capacity of lignitic coals which were obtained from Soma and Yataan / Turkey was investigated under different operational conditions such as solid-liquid ratio (S/L), reaction time, initial phenol concentration and temperature. Based on batch adsorption studies, it was observed that the phenol was completely adsorbed by coal depending on time of adsorption and the S/L ratio. From these results, the maximum adsorption values on the time axis at various S/L ratios were used and the fractions of phenol receptive adsorption sites on coal surfaces were calculated as 60 % and 43 % for Soma and Yataan coals, respectively. Freundlich adsorption isotherm was found to describe the adsorption of phenol on lignitic coals well. The Langmuir model did not describe the system as good as Freundlich model most probably due to the monolayer coverage assumption on this model. Activation energy and the maximum heat of adsorption calculated using adsorption data at different temperatures by the Arrhenious and Van.t Hoff equations were 10.3 and -20.2 kJ/mol, respectively. The low energies suggest that the adsorption of phenol on these lignitic coals were through physical interactions. An adsorption mechanism of phenol on lignite was discussed based on these findings. Residual water quality following adsorption in terms of major elements and heavy metals was within acceptable limits defined for wastewaters. The amount of organic matters dissolved from coals were also negligable. The presence of heavy metals as Cu, Zn etc. in water as a contaminant was also found to affect the removal of phenol by about 10-20 %

Production of nano CaCO3 by carbonization route

Thesis (Doctoral)--Izmir Institute Of Technology, Chemical Engineering, Izmir, 2011Includes bibliographical references (leaves: 152-163)Text in English; Abstract: Turkish and Englishxxiii, 181 leavesCalcium carbonate (CaCO3) is one of the most abundant materials in nature and widely used as filling material in various industries in order to decrease the product costs and to improve some mechanical properties of the composite materials. Because commercial calcite sold in the market is in granular form, in micron size, and inhomogeneous size distribution, the required properties can only be obtained by the recrystallization method. However, because the crystallization is an ionic reaction, there is not a standard procedure to obtain calcite in nano size, monodisperse, and different nano CaCO3 by the carbonization route. In order to understand the progress in crystal formation, crystals were synthesized by the chemical method by slow or fast addition of reactant into the solution. A mini reactor was built in a Ca(OH)2 solution for the carbonization method and reproducible results were obtained. During the precipitation reactions, pH and conductivity of the solutions were monitored. Particles were separated by centrifugation and dried at 103 oC in an oven overnight. Morphological characteristics of the precipitated CaCO3 samples were analyzed by SEM, XRD and FTIR. On the basis of XRD and FTIR analyses, the main crystal form of the precipitated samples was found to be calcite. Colloidal stability tests revealed that these nano particles do form aggregates. It was shown that the crystallization occurs on the surfaces of both the undissolved Ca(OH)2 particles and on the already grown CaCO3 particles as nano calcite evidenced from the XRD patterns of the samples. It was also observed that, in the late stage of the crystallization, because the pH decreased, the morphology of the particles was affected, indicating that erosion took place on the surface due to ionization. The effects of the enzyme, carbonic anhydrase, polyurethane foam, and organic solvents such as methanol, ethanol, toluene, hexane and benzene were also studied. It was observed that, in the presence of solvents nano crystals can be synthesized in the form of calcite, which were mostly monodisperse particles

Evaluation of bioactivity of pomegranate fruit extract against Alicyclobacillus acidoterrestris DSM 3922 vegetative cells and spores in apple juice

This research evaluated the antimicrobial activity of commercial pomegranate extract (POMELLA®, PE) against Alicyclobacillus acidoterrestris vegetative cells and spores (approximately 105 log CFU/mL) in apple juice (pH 3.82, °Brix 11.3) during storage at 37°C. After 240h, the cell counts were reduced from the initial log count (CFU/mL) by 2.84, 3.26, 3.32, 3.46 and 3.56 in the apple juice with PE at the concentrations of 2.5, 5, 10, 20 and 40μg/mL, respectively. On the other hand, counts of the control reached 7.36 log CFU/mL after 24h. The Weibull model satisfactorily described the survival curves of cell inactivation kinetics (R2 > 0.983). While the growth of all spores obtained from different sporulation media (potato dextrose agar, malt extract agar, Bacillus acidoterrestris agar, and Bacillus acidocaldarius agar) was inhibited in the apple juice with PE (2.5-40μg/mL), the control spores increased by 1.9-2.2 log CFU/mL after 336h. Based on the scanning electron microscopy (SEM) imaging, vegetative cells indicated substantial damage and spore germination was inhibited in the apple juice with PE. The results showed that PE can have possible uses as a natural antimicrobial to control the growth of A.acidoterrestris vegetative cells and spore germination in the apple juice. © 2015 Elsevier Ltd

The effect of sporulation medium on Alicyclobacillus acidoterrestris guaiacol production in apple juice

The present study evaluated the effect of sporulation medium on guaiacol formation from vanillin and vanillic acid by Alicyclobacillus acidoterrestris DSM 3922 in the reconstituted apple juice (pH 3.82, °Brix 11.3). For sporulation, potato dextrose agar and Bacillus acidoterrestris agar were used. After heat-activation, spores were turned into vegetative cells and inoculated into juice samples to a final concentration of 103 or 105 CFU/mL. Samples were incubated at 37 °C for 264 h and guaiacol concentration was determined using peroxidase enzyme colourimetric assay. Based on the results, the conversion of vanillic acid into guaiacol was faster than that of vanillin among both cell suspensions. Also, there were no significant differences among any of the samples inoculated into apple juice spiked with vanillin at the end of the incubation period (P > 0.05). In the case of vanillic acid, the guaiacol concentrations were significantly different among cells activated from spores produced on PDA and BATA (P < 0.05). The obtained results suggested that type of sporulation medium composition may affect the guaiacol concentration depending on inoculum level and type of precursor present in the apple juice

Effects of pomegranate and pomegranate-apple blend juices on the growth characteristics of Alicyclobacillus acidoterrestris DSM 3922 type strain vegetative cells and spores

The present study examined the growth characteristics of Alicyclobacillus acidoterrestris DSM 3922 vegetative cells and spores after inoculation into apple, pomegranate and pomegranate-apple blend juices (10, 20, 40 and 80%, v/v). Also, the effect of sporulation medium was tested using mineral [Bacillus acidoterrestris agar (BATA) and Bacillus acidocaldarius agar (BAA)] and non-mineral containing media [potato dextrose agar (PDA) and malt extract agar (MEA)]. The juice samples were inoculated separately with approximately 105CFU/mL cells or spores from different sporulation media and then incubated at 37°C for 336h. The number of cells decreased significantly with increasing pomegranate juice concentration in the blend juices and storage time (p<0.001). Based on the results, 3.17, 3.53, and 3.72 log cell reductions were observed in 40%, 80% blend and pomegranate juices, respectively while the cell counts attained approximately 7.17logCFU/mL in apple juice after 336h. On the other hand, the cell growth was inhibited for a certain time, and then the numbers started to increase after 72 and 144h in 10% and 20% blend juices, respectively. After 336h, total population among spores produced on PDA, BATA, BAA and MEA indicated 1.49, 1.65, 1.67, and 1.28 log reductions in pomegranate juice; and 1.51, 1.38, 1.40 and 1.16 log reductions in 80% blend juice, respectively. The inhibitory effects of 10%, 20% and 40% blend juices varied depending on the sporulation media used. The results obtained in this study suggested that pomegranate and pomegranate-apple blend juices could inhibit the growth of A. acidoterrestris DSM 3922 vegetative cells and spores

Extracellular enzyme production and enterotoxigenic gene profiles of Bacillus cereus and Bacillus thuringiensis strains isolated from cheese in Turkey

The aim of the present study was to investigate the biochemical characteristics, extracellular enzyme production and enterotoxigenic genes contents of 6 Bacillus cereus and 22 Bacillus thuringiensis strains, isolated from 100 cheese samples in Turkey. Crystal morphologies of B. thuringiensis strains were found either spherical (n = 12) or spherical and irregular-shaped (n = 10) by phase contrast microscopy. B. cereus and B. thuringiensis strains were found to produce extracellular enzymes, respectively: gelatinase (83% and 91%), DNase (83% and 77%), lecithinase (83% and 95%), protease on skim milk agar (100% and 100%), protease on milk agar (100% and 91%), protease on casein agar (83% and 77%), xylanase (100% and 45%), and cellulase (0% and 41%), and amylase (83% and 27%). All of the strains, except for Bt-D1, hydrolyzed Tween 20 (96%), but not Tween 80 or tributyrin. Pectinolytic activity was obtained to be the least frequent (4%). PCR analysis showed that all strains contained nheA, nheB, nheC and hblD genes. The hblA and hblC genes were present in 2 and 4 of B. thuringiensis strains, respectively. The bceT gene was detected in 1 B. cereus and 9 B. thuringiensis strains. The entFM gene was detected more frequently in B. thuringiensis (82%) than in B. cereus strains (50%). To our knowledge, this is the first report about the isolation and identification of enterotoxigenic B. cereus and B. thuringiensis strains from cheese samples in Turkey

On the Security and Feasibility of Safebook: A Distributed Privacy-Preserving Online Social Network

International audienceSafebook tackles the security and privacy problems of online social networks. It puts a special emphasis on the privacy of users with respect to the application provider and provides defenses against intruders or malicious users. In order to assure privacy in the face of potential violations by the provider, Safebook is designed in a decentralized architecture. It relies on the cooperation among the independent parties that represent the users of the online social network at the same time. Safebook addresses the problem of building secure and privacypreserving data storage and communication mechanisms in a peer-topeer system by leveraging trust relationships akin to social networks in real life. This paper resumes the contributions of [7, 9, 8], and extends the first performance and security evaluation of Safebook

Design of carrier swap bodies for agri truck 6 x 6

Tato diplomová práce se zabývá návrhem nosiče výměnných nástaveb za agrotahač 6x6 s maximální technickou hmotností 38000 kg a byla zpracována ve spolupráci s firmou ZDT Nové Veselí. První část práce je věnována legislativě a zejména pak popisu dostupných agrotahačů a obdobných konstrukčních řešení nejen nosičů výměnných nástaveb. V další části je popsán vlastní návrh koncepce nosiče výměnných nástaveb, na základě kterého byla na konci práce provedena pevnostní analýza. Součástí práce je také zhotovení výkresové dokumentace.This Diploma Thesis is dedicated to a proposal of a carrier swap bodies hooked up to a agrotruck 6x6 with a maximum technical weight 38000 kg and has been worked out in corporation with ZDT Nové Veselí company. The first section of the Thesis is occupied with legislation and then especially with a description of available agrotrucks and similar constuction solutions not just of the carrier swap bodies. In the following part of the Thesis the own carrier swap bodies construction proposal has been described, based on which the stress analysis has been done in the final part of the Thesis. Also the technical drawing forms an integral part of the Thesis.

PPS: Privacy-preserving statistics using RFID tags

As RFID applications are entering our daily life, many new security and privacy challenges arise. However, current research in RFID security focuses mainly on simple authentication and privacy-preserving identication. In this paper, we discuss the possibility of widening the scope of RFID security and privacy by introducing a new application scenario. The suggested application consists of computing statistics on private properties of individuals stored in RFID tags. The main requirement is to compute global statistics while preserving the privacy of individual readings. PPS assures the privacy of properties stored in each tag through the combination of homomorphic encryption and aggregation at the readers. Re-encryption is used to prevent tracking of users. The readers scan tags and forward the aggregate of their encrypted readings to the back-end server. The back-end server then decrypts the aggregates it receives and updates the global statistics accordingly. PPS is provably privacypreserving. Moreover, tags can be very simple since they are not required to perform any kind of computation, but only to store data