Adsorbent materials based on a geopolymer paste for dye removal from aqueous solutions

Geopolymers are porous materials that can be used as basic dye adsorbents in wastewater treatment. In this work, a green geopolymer paste synthesized from industrial and agricultural waste materials was employed as an adsorbent to remove the basic dye methylene blue from aqueous solutions. The geopolymer sample was characterized by X-ray fluorescence, scanning electron microscopy, Brunauer Emmet Teller surface area measurements, and particle size techniques. The isotherms of dye adsorption by the geopolymer sample were considered by the Langmuir and Freundlich adsorption models. The removal efficiency increased with increasing geopolymer dosage, contact time and temperature. The Freundlich isotherm exhibited the best fit to the adsorption data

Development of green geopolymer using agricultural and industrialwaste materials with high water absorbency

Geopolymer is a promising porous material that can be used for evaporative cooling applications. Developing a greener geopolymer using agricultural and industrial wastes is a promising research area. In this study, we utilize rice husk (RH), rice husk ash (RHA), metakaolin (MK), ground granulated blast furnace slag (GGBS), and palm oil fuel ash (POFA) to prepare geopolymer pastes, with alkali liquid as an activator. Many geopolymer samples have been prepared as per the Design of Experimental software (DOE), and its corresponding response surface mode and central composite design and later they were characterized. The samples were cured in an oven for 2 h at 80 °C, and thereafter stored at room temperature (~25-30 °C) prior to being tested for its water absorption and compressive strength. The effect of the different composition of precursors on water absorption, density, porosity, and the compressive strength of the prepared geopolymers have been investigated. The results showed that the compressive strength of geopolymers is directly proportional to the ratio of the alkali liquid. Post-optimization, the best geopolymer paste mixture was confirmed to contain 10% of RH, 15% RHA, 35% MK, 10% POFA and 30% of GGBS, with 72% desirability for maximum water absorption (~38%) and compressive strength (4.9 MPa). The results confirmed its applicability for evaporative cooling

Seroepidemiological Study of Visceral Leishmaniasis (Kala-azar) in Ardabil Province, Iran, 1986 – 2009

Introduction & Objective: Visceral Leishmaniasis (kala-azar) is the most important endemic disease in Northwestern Iran, particularly in Ardabil province. This study aimed to review the seroepidemiological studies which have been performed in Ardabil province during 1986-2009. Materials & Methods: In this descriptive analytical study, studies which have been carried out from 1986 through 2009 in Northwestern Iran about clinical, diagnostic and epidemiological features of Kala azar, using DAT, were reviewed. Collected data were analyzed using the SPSS software. Results: in total, 2703 of human visceral leishmaniasis were detected by direct agglutination test (DAT) in Ardabil province, 1787 (66.1%) of them were from Meshkin-shahr district, 837 (31%) cases were from Moghan district, and 79 (2.9%) cases were from Ardabil district. Ninety eight percent of the cases were under 10 years old while only 0.5% of the VL cases were ≥20 years old and 17% of them were under 1 year of age. Conclusion: Currently Kala-Azar is the most important endemic disease in Northwestern Iran, particularly in Ardabil province. Anti-Leishmania antibodies at the titers of ≥1:3200 using DAT along with clinical signs including fever, anemia and hepatosplenomegaly are considered as active visceral leishmaniasis. DAT antibody titer of 1/800 and lower and absent of clinical signs is considered as negative VL