[Removal of turbidity in raw water using chitosan in electrocoagulation process using aluminum electrodes]

Background and Objective: Raw water is one of the main sources of water supply in some communities. Filteration of surface water resources is a challenging point in the rainy seasons due to the highly turbidity. This study was done to evaluate the removal of turbidity in raw water using chitosan in electrocoagulation process using aluminum electrodes

Methods: In this the descriptive -analytical study, a Plexiglas electrocoagulation reactor in a lab scale to an approximate volume of 6 liter which was equipped with four aluminum electrodes having dimension of 200×20×2 mm was proposed. The effects of operating parameters including pH [5 to 9], applied voltage [10 to 30 V], the initial turbidity [100-600 NTU], initial chitosan concentration [0.5-2 mg/L] and contact time [5 to 30 min] were evaluated

Results: Turbidity removal efficiency was over 100% [pH=7, applied voltage=30 V and initial turbidity concentration of 100NTU] in the application of electrocoagulation with chitosan but in the application of electrocoagulation without chitosan removed 87% of turbidity in the same condition

Conclusion: Chitosan as coagulant aid in low amount can increase turbidity removal efficiency rather than application of electrocoagulation alone

[Removal of methylene blue dye from synthetic wastewater with bone char]

Dyes are organic materials with complex structures, toxic, carcinogenic, teratogenic, nonbiodegredable properties and the most important pollutants of textile industrial wastewaters. The goal of this study was to survey the feasibility application of bone char [BC] as a sorbent for the removal of methylene blue [MB] from synthetic wastewater. The sub goals of the research were to determine the adsorption isotherm, effects of primary concentration of dye, adsorbent dose, contact time, and pH for the adsorption of MB with BC. BC was prepared under laboratory conditions by using of electrical furnace at 400°C for 2h. The prepared BC was crushed and pulverized by standard ASTM sieves with range of 10-16 mesh [1.18-2 mm]. The chemical composition and solid structure of BC was analyzed using X-ray diffraction [XRD] and scanning electronic microscopy [SEM]. Measurement of the surface area was carried out by N2 gas via BET isotherm and Belsorb software. The concentration of dye was measured by photometric method [663nm]. Predominant composition of BC is calcium hydroxyl apatite [Ca5 [PO4]3OH with 14m2/g surface area. The results of this study showed that increasing of primary concentration of dye, adsorbent dose and pH [5 to12] would lead to increasing of adsorption/removal of MB dye. Equilibration of dye adsorption was reached at lapse of 2h and optimum pH for adsorption of MB with BC found in the rage of 8.5-12. Adsorption of MB with BC complies with freundlich isotherm [R2: 0.99]. Conclusion: Bone char is a cheap component that can be used as an adsorbent in water and wastewater treatment. Based on optimum pH of 8.5-12 found for the removal of MB and the fact that many of textile industrial wastewaters have an alkaline pH, this adsorbent can be used for the removal of dyes from these wastewaters

[ new endemic focus of visceral leishmaniosis in southeren Iran]

Visceral leishmaniosis [VL] is endemic in some parts of Iran. Mediterranean type of disease is present in Iran where its causative agent is Leishmania infantum and dogs are the main. reservoirs. Since many cases of the disease were reported from Noor-abad, in Fars province, we aimed to carry out an epidemiological survey on VL in human and animal reservoirs; [dogs] in Mahoor-Milaty district of Noor-Abad city at West North of Fars province. In this cross-sectional descriptive survey, E blood samples were randomly collected from all children