Microbiological and Chemical Quality of Water in Food Industries with Low Content of Water at End Products

"n "nBackground and Objectives: In the production of some high-consumed food products like cake, biscuit, chocolate and spaghetti water is used in the preparing of primary material and in the kneading processes. At the present study microbiological and chemical quality of consumed water in food industries of East Azerbaijan Province were studied."nMaterials and Methods: Eleven factories with different products were selected. Water samples were collected and analyzed regarding the microbiological contamination and chemical parameters, and heavy metals. In addition, condition of water quality in selected industry was surveyed during the summer."nResults: According to the results, monitoring of water quality in the studied industries is not suitable. The chemical characteristics of consumed water in those industries had major differences. Ni, Cr, Zn, Fe and Mn were present in all analyzed water but in lower concentration than national Maximum Contaminant Level (MCL). Pb was measured in higher concentration than MCL in spaghetti factory no. 2 and close to MCL in wiener and frankfurter and sugar industries. Cd was close to MCL in spaghetti factory no. 2 and wiener and frankfurter industries."nConclusion: It was concluded that for the safety and health of food products the food industries should use the public water supply system as water source at least in food processing units or in the units of preparing of primary materials. Also for the preventing of chemical pollution of food products it is necessary, pay more attention to the subject of water quality control according to the special water standard of food industries, and using less volume of water in some food industry isn.t acceptable reason for neglecting of water quality monitoring and assessing. In addition it is required to analyze heavy metals in the final products of those industries

REMOVAL OF CADMIUM FROM INDUSTRIAL EFFLUENTS BY ELECTROCOAGULATION PROCESS USING IRON ELECTRODES

The object of this study is the evaluation of cadmium removal from industrial wastewater by electrocoagulation process. For this study a glass tank in 1.56 L volume with four plate electrode was used to do experiments. The electrodes made of iron and connect to the positive and negative pole of DC power supply (bipolar mode). The tank was filled with synthetic wastewater that was containing cadmium ion in concentration 5, 50 and 500 mg/L and then it was started up. The percent of cadmium ion removal was measured at pH 3, 7 and 10 and in electric potential range of 20, 30 and 40 volts. At the end of each stage of experiment, volume of produced sludge was measured. The results obtained at different electrical potential showed that initial concentration of cadmium can effect on efficiency removal and for higher concentration of cadmium, higher electrical potential or more reaction time is needed. On the other hand, if the initial concentration increases, the time required of process should increase too. The final pH for iron electrodes was always higher than initial pH. As expected, the results showed that for a given time, the removal efficiency increased significantly with increase of current density. The highest electrical potential (40V) produced the quickest treatment with >99% cadmium reduction occurring after only 20 min. The result showed that, in this process, the use of different electrical potentials can provide a wide range of pH for doing this process and electrocoagulation process (using iron electrodes) is a reliable, safety, efficient and cost-effective method for removal of cadmium from industrial effluents, especially designed for pH =10 and voltage = 40V

Bioremoval of Lead by Use of Waste Activated Sludge

Biological removal of lead was observed in this study during treatment of synthetic solutions of this heavy metal by a sample of waste activated sludge (WAS) having MLSS concentration of 10000 mg/L. The objective was determining the capability of WAS in removal of lead in three different conditions of treatment: without any aeration and feeding, by simultaneous aeration and feeding and by aeration without feeding. Besides, the effect of initial metal concentration and contact time in these treatment stages were determined.Results showed that the efficiency of lead removal was reduced by increasing the initial metal concentration, but the changes of contact time had resulted in different responses depending to the test condition. Moreover, it was found that the effects of aeration and feeding in increasing the efficiency of treatment were more pronounced for the stage of treating lower concentrations of lead. The maximum removal of lead in the first step (without aeration and feeding) was 55.2 % in contact time of 75 minutes, in the second step (without feeding and by 12 hours aeration) 63.3% and third step it was 94.2 % in contact time of 48 hours .The initial lead concentration in these experiments was 5 mg/L

Methyl Tert-Butyl Ether Adsorption On Surfactant Modified Natural Zeolites

Surfactant-modified clinoptilolite-rich tuff was used for the removal of methyl tert-butyl ether (MTBE) from aqueous solutions. Clinoptilolite zeolite from Miyaneh region of Iran was treated with sodium chloride and then modified with hexadecyltrimethylammonium chloride (HDTMA-Cl) and n-Cetylpyridinium bromide (CPB) to be used in different experimental conditions. The ability of raw or Non-Modified Zeolite (NMZ) and Surfactant-Modified Zeolites (SMZ) to remove MTBE from aqueous solutions was investigated as a function of contact time, pH and concentrations of adsorbent and adsorbate, by using a batch technique in aqueous system. The removal of MTBE from aqueous solutions by modified zeolites seemed to be more effective than non-modified samples. Also, HDTMA-modified zeolite had more effective performance than CPB-modified zeolite. The adsorption efficiency of MTBE onto SMZS was found to increase by contact time and adsorbent concentrations, and by decreasing of pH and adsorbate concentrations. Empirical adsorption models of Langmuir and Freundlich were applied for the experimental data. Results showed that Langmuir isotherm was more suitable for this process. The experimental data fitted very well with the pseudo-second-order kinetic model. It was overally found that Surfactant-Modified Zeolites is an effective adsorbent for removal of methyl tert-butyl ether from contaminated solutions

Survey On Degradation Rates Of Trichloroethylene In Aqueous Solutions By Ultrasound

Sonochemical degradation of different compounds such as chlorinated aliphatic hydrocarbons is one of the recent advanced oxidation processes and it may be effective for removing low concentration organic pollutants from aqueous streams. Trichloroethylene (TCE) is one of these compounds that is mainly used as a degreaser. Important studies about TCE sonolysis have been focused at millimolar levels and natural pH, but in this study the ultrasonic degradation of TCE at different micromolar initial concentrations (30, 300 and 3000 µg/L) and 4 different initial pH with a 35 kHz frequency was investigated. Furthermore, the degradation of TCE by ultrasound with different concentrations of hydrogen peroxide at pH= 7 was also performed. Gas chromatography with FID detector was used for analyses of TCE. Results showed that the degradation of TCE increased with decrease in the initial concentration of TCE from 3000 to 30 µg/L at all initial pH. Initial pH of solution and different concentrations of H2O2 did not affect significantly the TCE destruction