A comparative study for boron removal from seawater by two types of polyamide thin film composite SWRO membranes

In this paper, field performance of a small-scale seawater reverse osmosis unit installed in Urla Bay-Izmir, Turkey was analyzed and presented. The design of SWRO system in Urla consists of two types of FilmTec polyamide thin film composite spiral wound seawater reverse osmosis membranes (high rejection FILMTEC XUS SW30XHR-2540 RO membrane and FILMTEC SW30-2540 RO membrane) which could be operated in parallel. To make a comparative study between two types of membranes regarding their desalination performances and boron rejections, each membrane was operated individually for each set of experiments. This comparison was made via investigation of the effects of feed seawater temperature (10–16 °C), operating pressure (55, 60 and 62 bar), and pH adjustment on the feed side (pH 7.0–7.5).     

Determinaton of proximate composition and mineral contents of blue crab (Callinectes sapidus) and swim crab (Portunus pelagicus) caught off the Gulf of Antalya

The proximate composition and mineral contents of blue crab (Callinectes sapidus) and swim crab (Portunus pelagicus), caught off the Gulf of Antalya, were investigated. The aim of this study was to demonstrate the nutritive value. Claw and body meat of these two species were analyzed. For both species there were no significant differences in the moisture, fat and ash contents of claw and body meats but protein contents of swim crab were significantly higher (P<0.05) than those found in blue crab. Na, K, Ca, Zn and Cu values for blue crab and swim crab were not significantly different. There were no significant differences between Na, K, Mg, Zn, Fe, Mn and Cu contents of claw and body meats of the two species.     

Effects of ochratoxin A on micronucleus frequenncy in human lymphocytes

Ochratoxin A (OTA( a nephrotoxic and carcinogenic mycotoxin, was investigated to examine its potency to induce micronuclei (MN) in cultured human lymphocytes. Lymphocyte cultures were treated for the last 48 h with OTA at concentrations of 25 μM , 10 μM , 1 μM , 100 nM , 10 nM , 1 nM , and 100 pM and absolute ethanol. At the highest concentration, OTA was found to induce MN in cytokinesis‐blocked lymphocytes (p < 05). The 25 μM OTA concentration also led to a clear decrease in the percentage of binucleated cells, probably due to cytotoxicity. OTA at the other concentrations tested did not induce MN frequency. These results indicate that a high concentration of OTA is genotoxic in cultured human lymphocytes.     

Use of eye fluid refractive index in sardine (<Emphasis Type="Italic">Sardina pilchardus</Emphasis>) as a freshness indicator

In this study the usage of eye fluid refractive index as a freshness indicator for sardine (Sardina pilchardus) was investigated. Eye fluid refractive index measurements and quality control analyses of sardine during storage at 0°C and +4°C were performed at 24h intervals. According to the sensory analysis results, the sardines stored at 0°C and +4°C had a shelf life of 6 and 4days, respectively. The changes in eye fluid refractive index values during storage at 0°C were not significant while the changes at +4°C were significant (p<0.01). TVB-N and TMA-N values significantly (p<0.01) increased. No microbiological growth was observed at 0°C, however the increase in microorganism counts was significant at +4°C. As a result, eye fluid refractive index measurements can be used as a quality criterion for sardine freshness, when stored at +4°C.     

Inhibition of lipid oxidation in anchovy oil (Engraulis encrasicholus) enriched emulsions during refrigerated storage

The aim of this study was to produce a functional emulsion product enriched with anchovy (Engraulis encrasicholus) oil. Tomato and garlic extracts were added to perform oxidative stability. Tomato and garlic extracts were added to avoid oxidative degradation in such a product. The plant extracts delayed the formation of primary and secondary oxidation products. The value of conjugated diens (3.07 ± 0.15) was markedly low in the emulsions containing garlic extract at the end of the storage period. The p–Av values of the emulsions treated with the extracts were significantly (P < 0.01) lower than untreated samples. TBARS formation increased slightly, therewithal statistical difference was not observed in the samples treated with garlic extract during the storage. Strong odour and flavour of the garlic suppressed the odour of fish oil. The panellists preferred the flavour, odour and aroma characteristics of the samples treated with the extracts.     

Esterification of free fatty acids in waste cooking oils (WCO): Role of ion-exchange resins

Although WCO plays a crucial role for the economical production of biodiesel, free fatty acid (FFA) level in the nature of WCO cause saponification problems during transesterification. Acidic ion-exchange resins can be used to decrease WCO free fatty acid level. In this study, activities of resins (Amberlyst-15 (A-15), Amberlyst-35 (A-35), Amberlyst-16 (A-16) and Dowex HCR-W2) in direct FFA esterification were examined in the temperature range of 50–60 °C and the effect of catalyst amount (1–2 wt%) on FFA conversion was also analyzed. FFA conversion increased with increasing reaction temperature and catalyst amount. Order of catalytic activities was found as A-15 > A-35 > A-16 > Dowex HCR-W2. This was related to the size of average pore diameters and magnitude of BET surface area.     

An electrochemical model for reduction of MnO2 with Fe2+ ions

The reduction kinetics of MnO₂ by Fe²⁺ ions in acidic solution have been studied. The effects of stirring rate, particle size, temperature, Fe²⁺ and H⁺ concentrations have been investigated. Diffusional resistances are negligible above 900 r.p.m. and the rate is controlled by electrochemical reaction. A mixed-potential model developed to describe metallic corrosion has been used in combination with the shrinking core model to explain the reaction kinetics. The overall reaction has been written in terms of cathodic and anodic half-cell reactions. The Tafel equation has been used as a starting point to derive a rate equation. A value of 0.5 has been obtained for charge transfer coefficients, which implies the existence of symmetrical charge barriers. The kinetics of the cathodic reduction reaction are first order with respect to the proton concentration.Nomenclature D diffusion coefficient (cm² s^–1) - D _i impeller diameter (cm) - D _T reactor diameter (cm) - d ₀ initial particle diameter (m) - E e.m.f. between platinum and saturated calomel electrode (V) - F Faraday constant - e electrode potential (V) - e _j liquid-junction potential (V) - k _a rate constant of anodic half-cell reaction - k _c rate constant of cathodic half-cell reaction - k ₁ Mass transfer coefficient (cm s^–1) - m ₀ amount of MnO₂ charged in the reactor (g) - M Molecular weight of MnO₂ - N Stirring speed (r.p.m.) - Re _s Reynolds number for stirring (ND _i ²/) - Re _p Reynolds number for particle (d ^4/31/3/) - Sc Schmidt number (/D) - Sh Sherwood number (k ₁ d/D) - V Reaction volume (dm³) - X Conversion factor Greek letters _i stoichiometric coefficient of reactant i in Equation 1 - stirring energy per unit volume - kinematic viscosity (cm² s^–1) - time required for complete conversion (min)     

Antimicrobial Contamination Removal from Environmentally Relevant Matrices: A Literature Review and a Comparison of Three Processes for Drinking Water Treatment

The effectiveness of conventional water treatment technology in preventing the dissemination of antimicrobial contamination has been questioned due to significant rates of antibiotic resistance elements found both in solid wastes and in effluents. This implies that preventive efforts must cover both solid waste quality and effluent quality monitoring. This article presents a review of the occurrence data for a number of antibiotics and antibiotic resistance carriers along with the effectiveness of conventional and advanced technologies in the removal of antimicrobial contamination from various matrices. Although the current literature suggests that the advanced oxidation processes are more promising, cost viable oxidant doses may not be sufficient to reach targeted removal efficiencies especially in biosolids and manure. As a result, antimicrobial contamination can inevitably reach natural waters and contaminate drinking water sources. In this context, a comparison of the effectiveness of three oxidation processes on the removal of a resistance carrier bacterial plasmid DNA was studied. The relative effectiveness of ozonation or heterogeneous photocatalysis over conventional chlorination was demonstrated.