Abstrait

Effect of Environmental Factors in Biological Removal by Halophilic Bacteria: Optimization by Taguchi Statistical Approach

Zahra Kahrarian , Mojtaba Taran and Ahmad Tajehmiri

Background and Objective: With the advent of the industry, the risk of heavy metals entering the environment has increased. Industrial sewage is considered as an important source of water pollution. Heavy metals, including cadmium, have toxic effects on humans and the environment. Today, the use of microorganisms, including bacteria, in biological refining has been considered as an environmentally friendly and cost effective method. In this study, the ability of Halomonas elongata IBRC-M10433 strain isolated from sediments of Lake Urmia to remove cadmium from metals has been considered. The aim of this study was to optimize the environmental conditions of removal of Cadmium metal by Halononas elongata IBRC-M10433.

Method: Design of Experiments Taguchi method to determine the optimum conditions relative to environmental factors such as Ammonium chloride (NH₄Cl) as a source of nitrogen, and phosphate potassium (K2HPO₄) as a source of phosphorus and cadmium concentrations in biological removal of cadmium was studied by the bacterium Halomonas longata IBRC- M10433.

Materials and methods: Taguchi experimental design was designed to determine the relative optimal conditions of environmental factors such as ammonium chloride (NH₄Cl) as a source of nitrogen, potassium phosphate (K2HPO₄) as a source of phosphorus, cadmium concentration in cadmium biodegradation by Halomonas Elongata IBRC-M10433 was studied. Data analysis was performed using Qualitek-4 software and the relative importance of each of the factors was determined.

Results: Optimum absorption conditions at Potassium phosphate 0.3 g/L, 100 mg cadmium and Ammonium chloride 2 g/L was determined at 37°C and pH 7.

Discussion and conclusion : Due to high costs and environmental problems, conventional methods of removing heavy metals are an effective and cost effective biological removal. The use of relative salt bacteria is beneficial in bio-refining with a high uptake of heavy metals.