پديدآورندگان :
Foroutan Rauf Polymer Research laboratory, Department of Organic and Biochemistry, faculty of chemistry, university of Tabriz, Tabriz, Iran, , Mohammadi Reza r.mohammadi@tabrizu.ac.ir Polymer Research laboratory, Department of Organic and Biochemistry, faculty of chemistry, university of Tabriz, Tabriz, Iran;
چكيده فارسي :
Water pollution caused by toxic heavy metals constitutes one of the most serious environmental problems. Chromium is one of the toxic heavy metal has been extensively used in industries including electroplating, leather tanning, metal plating, battery and petroleum refining. In aqueous environments chromium exists in two stable oxidation states, trivalent and hexavalent (Cr (III) and Cr (VI)). The Cr (VI) form is considered more toxic than Cr (III) and a suspected carcinogenic material. Hexavalent chromium is very soluble and mobile in the natural environment [1]. There are several strategies for Cr (VI) removal including chemical precipitation, membrane separation, reduction, ion exchange and adsorption [2]. Recently, the adsorption method has promisingly been used for the removal of heavy metals from water and wastewater. This method, compared with other physical and chemical methods, is facile, low-cost, efficient, and easy-design [3]. Activated carbon is widely and successfully used to remove various heavy metals ions from an aqueous solution due to its absorptive capacity. However, this adsorbent poses many restrictions, such as non-renewability of initial materials and high product costs [3]. In order to produce activated carbon, a variety of agricultural materials and wastes can be used. Generally, any inexpensive material that has a large amount of carbon in its structure and a small amount of minerals can be used as raw material for the production of activated carbon. Wood of some plants, charcoal, brown charcoal, lignin, coconut shell, shell fruits such as hazelnuts, walnuts are the most commonly used raw materials to produce activated carbon. In this study, date Phoenix dactylifera was used for the production of activated carbon. Dates were prepare from local formers and then their shells were separated and washed with water to remove excess materials. After washing, date palm (30 g) were placed in an oven at 400 °C for 2 h in order to carbonize the date palm. The resultant activated carbon was characterized by FTIR, SEM, EDAX, and Map techniques. Factors affecting removal efficiency of Cr (VI) ions such as pH, dosage, contact time and initial concentration of Cr (VI) were investigated. The best evaluated pH was 2 for activated carbon.
