Category Archives: Environment

Ability of Natural Zeolite Ore to Bind Cadmium from Aqueous Solutions

Batool Salameh*(1) and Leila Habib(1)  

 (1). Department of Soil and Water Sciences, Faculty of Agriculture, Tishreen University, Latakia, Syria.

(*Corresponding author: batoolzaka@gmail.com).

Received: 02/02/2018                                Accepted: 19/06/2018

Abstract

The objective of this study is to characterize natural zeolite ore by the use of X-Ray Diffraction (XRD), and to study the ability of natural zeolite ore to bind cadmium from aqueous solutions. Adsorption factors such as zeolite particles size, initial Cd concentration, shaking time, solution: zeolite ratio and pH  were studied. Adsorption isotherms constructed then by the use of batch adsorption experiments. Langmuir and Freundlich models were used to represent adsorption data. XRD study showed that Analcime and Phillipsite are the main zeolitic minerals, and it contains non zeolitic minerals such as quartz, calcite and smectite minerals. Natural zeolite ore has high ability to remove cadmium from water solutions, and had 28 mg/g as maximum adsorption capacity. Adsorption increased with increasing initial cadmium concentration, shaking time and initial pH degree. pH 4-6 showed best range for adsorption. Adsorption is not affected by zeolite particle size and solution: zeolite ratio. This study was conducted at Soil Chemistry Laboratory during 2016/2017, but XRD study was conducted at the Atomic Energy Commission of Syria.

Key word: Zeolite ore, X ray diffraction, Adsorption, Cadmium.

Full paper in Arabic: PDF

The Bacterial Fact of Sawa Lake in Samawa City Southern Iraq

Asaad M. R. Al-Taee*(1)  Eman A. Al-Emara(1) and Anwar A. Maki(1)

(1). Marine Science Center, University of  Basrah, Barah, Iraq.

(*Corresponding author. Dr.  Asaad M. R. Al-Taee. E-mail: amraltaee@yahoo.com).

Received: 23/10/2018                                Accepted: 16/12/2018

Abstract

Bacteriological investigation had been performed for samples collected from Sawa lake. The samples included: water samples, sediment samples, crystallized gypsum, which forms the walls of the lake, aquatic plant samples (Chara sp.), Zooplankton samples (Arctodiaptomus salinus) and fish samples (Planliza abu). The bacterial analysis included, heterotrophic bacteria (HB), total coliforms (TCs), fecal coliforms (FCs), halophilic bacteria (Halococcus sp. and Halobacterium sp.), endophytic bacteria, sulfate and sulphite reducing bacteria, Clostridium perfringens and Vibrio sp.  The results showed that, only HB and halophilic bacteria were presented, while the lake was clear from any types of sulfate and sulphite reducing bacteria and pathogenic bacteria in the winter season.

Key words: Sawa Lake, Halophilic bacteria, Pathogenic bacteria.

Full paper in English: PDF

Biosynthesis of Medium Chain Length Poly-β-hydroxybutyrate by Pseudomonas aeruginosa Dw7

Eman H. Gatea٭(1) Saad H. Khudair(1) and Nadhim H. Haider(2)

(1). Environment and Water Directorate, Ministry of Science and Technology, Baghdad, Iraq.

(2). Collage of science, Baghdad University, Baghdad, Iraq.

(*Corresponding author: Dr Eman Gatea. E-mail: eman77aa@yahoo.com).

Received: 04/11/2017                              Accepted: 14/12/2017

Abstract  

Polyhydroxya lkanoates (PHAs), are a promising family of bio-based polymers, which considered to be alternatives to traditional petroleum-based plastics. Poly-β – hydroxybutyrate (PHB) is the most known degradable biopolymers, produced by bacterial genera. It is generally accepted that PHB can be used instead of plastic to solve one of the greatest problems facing the environment. Pseudomonas aeruginosa Dw7 was grown on mineral salt medium supplemented with waste cooking of corn oil for the synthesis of a medium chain-PHB. This study is divided into three steps, at first fermentation of P.seudomonas aeruginosa Dw7, which was carried out aerobically at optimum temperature of 30 ˚C and 500 rpm of agitation speed. Lab scale bioreactor (5L) operated as a batch culture system for 80 hours. The highest cell dry weight (CDW) of bacteria reached to 5.3 g/l observed after 60 h of operation, which was corresponding to 62.6 % of PHB. The results suggested the efficiency of the system for production of PHB in large scale. Many solvent systems were conducted to evaluate the best solvent for PHB extraction from bacterial cell in the second step. Chloroform–hypochlorite dispersion extraction was followed by that extraction with chloroform showed the best solvent system for yielding of PHB. Relatively; it has the high rate with 63% yield of PHB. Characterization study of PHB was the last step. PHB were included chemical, physical; mechanical and solubility properties of the produced PHB have been characterized by many analyses techniques, comprising Gas Chromatography Mass Spectrometry (GC-MS), Fourier-transform Infrared Spectroscopy (FTIR), X-Ray diffraction (X-Ray) and melting point. PHB was a yellowish white crystal, soluble in chloroform and other chlorinated hydrocarbons like dichloromethane, dichlorethane and chloropropane. X-Ray diffraction (XRD) study was carried out to check if the polymer had a crystalline or amorphous structure. The increased intensity of peaks showed that the polymer had more organized packed crystalline structure. The results of the GC-MS recorded that there were 9 different active peaks predictive. The two major compounds that were produced by P. aeruginosa Dw7 were then identified as undecanoic acid which eluted at 15.4 min and tridecanoic acid at 17.3 min with relative abundance of 100% and 33.14% respectively. The characteristic FTIR peaks for PHB indicated that the most prominent marker band for the identification of PHB is the ester carbonyl band at C=O, OH and C-O.

Keywords: Pseudomonas aeruginoa, Poly-β- hydroxybutyrate, Bioreactor, Extraction with solvents.

Full paper in English: PDF

Evaluation of Afforestation and its Ecological and Tourist Effects in Dahr al-Quseir Area (Homs / Syria)

Issa Noufal(1) Raed Al Muhammad*(2) Khaled Fahed(2) Ahmad Al Mukdad(3)

 (1). Natural Resources Directorate, Agricultural Research Center in Homs, General Commission for Scientific Agricultural Research (GCSAR), Damascus Syria.                 (2). Forestry Research Department, GCSAR, Damascus, Syria.                                     (3). Environment Research Department, GCSAR, Damascus, Syria.           (*Corresponding author: Eng. Raed Al Muhhamad. E-Mail: raedmd1973@gmail.com).

Received: 09/10/ 2015                           Accepted: 19/03/ 2016

Abstract

This study was conducted in Dahr al-Quseir (Homs/Syria) meanwhile the afforestation project during the years 2011-2014, to evaluate the status of afforestation with Castanea sativa and its adaptability with the environment, as well as to identify certain aspects relating to human activity and their effect on afforestation. The study showed the survival and adaptation of the planted forest species with the new climate and soil factors. This was evident through composition, structure of vegetation cover. The study also showed that the random human intervention resulted an imbalance in growth affecting tree height that averaged 6.02 m in case of uncontrolled human intervention versus 12.9 m for the controlled intervention. The average of tree height was 8.67 m when the plants were naturally grown. Tree diameter decreased to 24.33 cm in case of random human intervention, 29.38 cm for controlled intervention, and 27.67 cm under the natural conditions. However, the western side predominated the other ones in terms of tree height and diameter, whereas the vegetation cover surpassed at the eastern side. Moreover, the study revealed that the location had an ecologically important role for soil protection and climate mitigation, besides a considerable human presence represented by tourism.

Keyword: Castanea sativa, Afforestation, Exposure, Height, Diameter.

Full paper in Arabic: Evaluation of Afforestation and its Ecological and Tourist Effects in Dahr al-Quseir