[Efficiency of Pistaciaatlantica seed extract as natural coagulant in the removal of Reactive Red 198 dye from aqueous solution]

Textile dyes and other dyes used in various industries are among the largest organic compounds which can be a major hazard to the health and environment. Therefore treatment of wastewater before discharging it into the environment is necessary. In the present study we investigated the efficiency of Pistacia atlantica seed extract in a batch system for removal of Reactive Red-198 dye from aqueous solutions. This is a basic- applications study conducted in laboratory. The effects of independent variables such as coagulant dose [0.1-1 ml L-1], initial dye concentration [50, 100, 150 and 200 mg/l] and pH [2-12] were investigated. To measure the residual concentration of dye we used a spectrophotometer at the wavelength of 520 nm. Excel software was used for data analysis. The optimum pH for Reactive Red-198 removal by coagulation using Pistacia atlantica seed extract was 12, with a coagulant dose of 0.5 ml/L. The highest removal rates were 83.12, 84.20, 87.36 and 88.49% at initial dye concentrations of 50, 100, 150 and 200 mg/L respectively, which could be result of precipitation, co-precipitation and adsorption mechanisms. According to the results of this study, Pistacia atlantica seed extract was an inexpensive coagulant, and also quite effective in the removal of Reactive Red-198 dye from aqueous environments

[Survey of arsenic removal from water by coagulation and dissolved air floatation method]

Arsenic is one of the most toxic and dangerous elements in drinking water that with increase in its application in agriculture, development of applications in agriculture, livestock, medicine, industry and other cases its entry to water resources and environment is much easier. Arsenic is a poisonous, cumulative substance and inhibitor of SH group enzymes and various studies revealed a significant correlation between high concentrations of arsenic in drinking water and liver cancer, nasal cavity cancer, lungs, skin, bladder and kidney cancer in men and women and prostate and liver in men. The aim of this was survey of arsenic removed from water using dissolved air floatation mechanism. At present study in first step for determination best conditions of arsenic removal by dissolved air floatation method, optimum amount of coagulants determined and then synthetic solution of arsenic [50, 100 and 200 micro g/L] prepared using sodium arsenate. In third step arsenic removal efficiency under various variables such as arsenic concentration, flocculation and floatation time and saturation pressure were analyzed. Finally residual arsenic concentration was determined by the silver diethyl dithiocarbamate method. Effect of optimum condition on arsenic removal efficiency at various initial concentration 50, 100 and 200 microg/Lshowed that the best coagulant for removal of arsenic is polyaluminumchloride. Also maximum efficiency [99.4%] was obtained in initial concentration equal 200 microg/L. It can be concluded that dissolved air floatation method with poly aluminum chloride as coagulant have high efficiency for arsenic removal even at high concentrations and therefore this method can be used for removal of arsenic from water as a suitable and safe option

Removal of cadmium from aqueous environments by electrocoagulation process using aluminum electrodes

The purpose of this study was the evaluation of cadmium removal from industrial wastewater by electro coagulation process using aluminum electrodes. For this study a glass tank with 1.87 liter volume containing four plate aluminum electrodes was used to do experiments. The electrodes were connected to the positive and negative poles of DC power supply [bipolar mode]. The tank was filled with synthetic wastewater containing cadmium ion in concentration of 5, 50 and 500 mg/l and then it was started up. The amount of cadmium ion removal was measured at pH 3, 7 and 10 and in electric potential range of 20, 30 and 40 volts. The results obtained at different electrical potentials showed that initial concentration of cadmium can affect on efficiency removal; moreover, for higher concentration of cadmium, higher electrical potential or more reaction time is needed. On the other hand, if the initial concentration increased, the time required of process had to increase too. The final pH was always higher than initial pH. As expected, the results showed that in a given time, the removal efficiency increased significantly with the increase for the current density. The highest electrical potential [40 v] produced the quickest treatment with >99% cadmium reduction occurring after only 20 min. The results showed that, in this process, the use of different electrical potentials can provide a wide range of pH for doing this process. The method was found to be highly efficient and relatively fast compared to conventional existing techniques and, it can also be concluded that the EC process has the potential to be utilized for the cost-effective removal of heavy metals from water and wastewater

[Aortopexy for treatment of severe tracheomalacia, report of three cases]

Tracheomalacia is abnormal collapse of the tracheal wall. It may occur in an isolated lesion or can be found in combination with other lesions that cause compression of the airway tracts. Tracheomalacia is usually benign, with symptoms due to airway obstruction. Recurrent pneumonia is common in these patients, presumably because airway collapse during coughing prevents effective clearance of airway secretion. The majority of these patients will respond to conservative management, consisting of humidified air, chest physiotherapy, slow and careful feedings, and control of infection and secretion with antibiotics. Surgical therapy is required when conservative measures are not adequate or when reflex apnea is present. Surgery includes correction of the underlying cause, such as vascular ring, teracheostomy, and aortopexy aortopexy is the accepted operative treatment for severe tracheomalacia. The standard surgical approach involves a left anterior thoracotomy often under broncoscopic control. In this paper we report aortopexy in 3 patients with severe, intractable tracheomalacia secondary to esophageal atresia, bronchogenic cyst and huge mediastinal cystic lymphangioma. The children with airway obstruction with or without lung infection especially in patients susceptible to tracheomalacia should examine with rigid bronchoscope for diagnosis. If bronchomalacia confirmed and conservative managements were not effective, aortopexy is one of the treatment modalities that were effective in our patients with good to excellent results

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