Erdal Öbek

Removal of Zinc(II) by Activated Carbon Prepared from Almond Husks under Different Conditions

Activated carbon was prepared from almond husks by activation at different temperatures in the absence (MAC-I) and presence (MAC-II) of H2SO4. The ability of the activated carbon to remove zinc(II) ions by adsorption from aqueous solutions was investigated, varying several conditions such as pH, the carbonisation temperature of the husk, the initial concentration of metal ions, the contact time and the adsorbent concentration. The optimum conditions were found to be a pH value of 5.5, a carbonisation temperature of 700°C, a contact time of 60 min and an adsorbent concentration of 4 g/l. The results obtained indicated that effective uptake of Zn(II) ions was achieved when the carbon prepared by heating almond husks at 700°C was activated by the addition of H2SO4. A 92% removal of Zn(II) ions was achieved at an initial concentration of 20 mg/l and an adsorbent concentration of 4 g/l. When the adsorbent concentration was increased to 40 g/l, the adsorption density decreased from 4.5 mg/g to 0.47 mg/g for MAC-II. The Langmuir and Freundlich constants were both calculated, and the data found to be fitted reasonably well by the Langmuir isotherm. The adsorption capacities for MAC-I and MAC-II as calculated from the Langmuir isotherm were 30.864 mg/g and 35.336 mg/g, respectively.

Determination of degradation of radioactivity and its kinetics in aerobic composting

In this study, the kinetics of disappearance of radioactivity in aerobic composting was investigated. For this purpose, compost materials were prepared by mixing sugar beet wastes, wine factory wastes (grape wastes), straw and biological treatment sludge in different amounts. While alpha-radioactivity was not initially detected in all composting materials, the composting materials had some beta-radioactivity. In the mixtures of sugar beet wastes--straw-biological treatment sludge (1), sugar beet wastes-wine factory wastes (grape wastes)-biological treatment sludge (II) and wine factory wastes (grape wastes)-biological treatment sludge (III), the beta-radioactivity reduced by 82%, 58%, 85% respectively of initial values after 52 d. The beta-radioactivity degradation in the composting process could be represented by first-order kinetics and reaction rate constants of mixtures of I, II and III were k = 0.0693 d(-1) (R2 - 0.84), k = 0.0453 d(-1) (R2 = 0.98), k = 0.0234 d(-1) (R2 = 0.97), respectively.

Investigation of relationships between removals of tetracycline and degradation products and physicochemical parameters in municipal wastewater treatment plant.

Determination of the effect of physicochemical parameters on the removal of tetracycline (TC) and degradation products is important because of the importance of the removal of antibiotics in Wastewater Treatment Plant (WWTP). Therefore, the purpose of this study was to investigate the relationships between removals of TC and degradation products and physicochemical parameters in Municipal Wastewater Treatment Plant (MWWTP). For this aim, (i) the removals of physicochemical parameters in a MWWTP located in Elazığ city (Turkey) were determined (ii) the removals of TC and degradation products in MWWTP were determined (iii) the relationships between removals of TC and degradation products and physicochemical parameters were investigated. TC, 4-epitetracycline (ETC), 4-epianhydrotetracycline (EATC), anhydrotetracycline (ATC), and physicochemical parameters (pH, temperature, electrical conductivity (EC), suspended solids (SS), BOD5, COD, total organic carbon (TOC), NH4(+)-N, NO2(-)-N, NO3(-)-N and O-PO4(-3)) were determined. The calculation of the correlation coefficients of relationships between the physicochemical parameters and TC, EATC, ATC showed that, among the investigated parameters, EATC and SS most correlated. The removals of other physicochemical parameters were not correlated with TC, EATC and ATC.

Antioxidant Response in Duckweed After Exposure to Secondary Effluent from Municipal Wastewater Treatment Plant, Elazığ, Turkey

The aim of this study is to evaluate the effects of the effluent of Elazig Municipality Wastewater Treatment Plant on the oxidative defense capacity of aquatic plants (Lemna minor L. and Lemna gibba L.). For this purpose, malondialdehyde (MDA), glutathione (GSH), oxidized glutathione (GSSG), vitamin A (retinol), vitamin E (α-tocopherol), and vitamin C (Ascorbic acid) levels were determined by the HPLC (high performance liquid chromatography) in the control groups and the groups adapting to reactors fed with discharge water. The depletion of vitamins (A, E, and C), decrease of GSH/GSSG ratio, and increase of MDA that reflect a precarious state of the cell in L. minor L. and L. gibba L. were observed after exposure to wastewater. It can be suggested that the selected biomarkers are useful in understanding the biochemical mechanisms of the secondary effluents from wastewater treatment plant in L. minor L. and L. gibba L. as early warning indicators.

Phytoremediation of Tetracycline and Degradation Products from Aqueous Solutions

The present study aims at phytoremediation of Lemna gibba L. in aqueous solutions with different concentrations of TC and Degradation Products (DPs). It also tries to determine whether there are differences in TC, ETC, EATC, and ATC levels, accumulated by Lemna gibba L. Exposure concentrations of 50, 100, and 300 ppb have been selected for TC and DPs, showing that the highest TC50, TC100, and TC300 concentrations in the plant have been 23.5+1.1, 80.1+3.9, and 274+13 ppb, respectively, while the highest ETC50, ETC100, and ETC300 have proven to be 39.5+1.9, 47.8+2.4, and 168+8.4 ppb, respectively. The highest EATC50, EATC100, and EATC300 concentrations in the plant have been 45.3+2.3; 65+3.0 and 173+9.0 ppb, respectively, whereas the highest ATC50, ATC100, and ATC300 concentrations in Lemna gibba L. have been 34.7+1.7, 39.6+0.2, and 114+5.6 ppb, respectively. TC, ETC, EATC, and ATC concentrations in Lemna gibba L. have increased with the increase of initial TC, ETC, EATC, and ATC concentration.

SIZINTI SUYUNUN ARITIMI İÇİN SU MERCİMEKLERİ KARIŞIMININ KULLANILMASI: I. NUTRİENTLER

Bu calismada, sizinti suyu aritimi icin Lemna gibba L., Lemna minor L ., Spirodela polyrrhiza ve Wolffia arrhiza’ dan olusan su mercimekleri karisimi kullanilmis ve bitkili kesikli sistemde nutrientlerin degisimleri arastirilmistir. Calismada, NH 4 + -N, NO 2 - -N, NO 3 — N ve O-PO 4 3- konsantrasyonlari tespit edilmistir. Deneysel calismalar 2 farkli derinlikte (5 ve 10 cm) ve farkli hidrolik bekletme surelerinde gerceklestirilmistir. En yuksek NH 4 + -N giderim verimi (%75,3), 5 cm derinlikteki reaktorde 9. gunde tespit edilmistir. NO 2 - -N ve NO 3 - -N konsantrasyonlarinda herhangi bir giderim olmadigi gozlenmistir. En yuksek O-PO 4 3- giderim verimi 5 cm derinlikteki reaktorde %44,6 olarak tespit edilmistir.