Sharif Digital Repository

The presence of highly toxic cyanides in the effluent of coke oven of steel industries is considered as a critical problem. Owing to high levels of toxicity, control and removal of cyanide are of great importance in this industry. Biological removal of cyanides by indigenous microorganisms offers inexpensive, safe and environmentally compatible option in comparison with chemical and physical methods. The present study primarily focused on the isolation and purification of the microorganisms which utilize cyanide as the sole source of Nitrogen in alkaline conditions. The isolated bacterial strains were investigated through variety of bacteriological and biochemical reactions as well as... 

HCN is a highly valuable precursor to many chemical compounds ranging from polymers to pharmaceutical. Although cyanide can be destroyed and recovered by several processes, it is still widely discussed and examined due to its potential toxicity and environmental impact. The treatment methods for cyanide in common use today are physicochemical processes which have high operating costs and also produce chemical waste. Recently, biological processes have been studied because they are inexpensive and no effect to the environment. Therefore to achieve this object, Stimulation of indigenous microorganisms for waste degradation is a common technology. The process effluent from the gold extraction... 

In this research, fabrication of a mediator free nano-biosensor for the detection of cyanide has been studied. This biosensor utilizes 75 nm diameter (nano) ZnO particles synthesized with sol- gel method for modification and immobilization of Horseradish peroxidase (HRP). Cyanide plays inhibitory role in decomposition of H2O2 while HRP plays catalyst role in this reaction. Cyanide inhibits enzyme activity thorough binding with enzyme active sites and result in decreasing electrical current in electrochemical decomposition of H2O2. Amperometery response of biosensor shows linear relation between inhibition percent and cyanide concentration in range of 3µM - 24µM with detection limit of 0.62µM... 

Cyanide ion is one of the materials used in various industries related to metallurgy, the release of which in the environment causes water, air and soil pollution. Numerous researchers have used different methods to remove this pollutant from the environment. Comparing these methods with each other, photocatalytic processes have attracted a lot of attention due to the use of sunlight as a sustainable energy source, good efficiency, low cost, etc. Therefore, in the present study, first the heat-treated graphite carbon-nitride photocatalyst was synthesized and then characterized by X-ray diffraction (XRD) tests, infrared spectroscopy (FT-IR), scattered reflectance spectroscopy (DRS),...