Density assessment and mapping of microorganisms around a biocomposting plant in Sanandaj, Iran.

Exposure to microorganisms can cause various diseases or exacerbate the excitatory responses, inflammation, dry cough and shortness of breath, reduced lung function, chronic obstructive pulmonary disease, and allergic response or allergic immune. The aim of the present study was to investigate the density of microorganisms around the air of processing facilities of a biocomposting plant. Each experiment was carried out according to ASTM E884-82 (2001) method. The samples were collected from inhaled air in four locations of the plant, which had a high traffic of workers and employees, including screen, conveyor belt, aerated compost pile, and static compost pile. The sampling was repeated five times for each location selected. The wind speed and its direction were measured using an anemometer. Temperature and humidity were also recorded at the time of sampling. The multistage impactor used for sampling was equipped with a solidified medium (agar) and a pump (with a flow rate of 28.3 l/m) for passing air through the media. It was found that the mean density of total bacteria was >1.7 × 103 cfu/m3 in the study area. Moreover, the mean densities of fungi, intestinal bacteria (Klebsiella), and Staphylococcus aureus were 5.9 × 103, 3.3 × 103, and 4.1 × 103 cfu/m3, respectively. In conclusion, according to the findings, the density of bacteria and fungi per cubic meter of air in the samples collected around the processing facilities of the biocomposting plant in Sanandaj City was higher than the microbial standard for inhaled air.

Solar degradation of Direct Blue 71 using surface modified iron doped ZnO hybrid nanomaterials.

This paper reports photodegradation of Direct Blue 71 under irradiation by sunlight. We synthesized Fe:ZnO nanomaterials under mild hydrothermal conditions (P = autogenous, T = 100 °C, t = 18 h). The precursors were Fe(2)O(3) as dopant, n-butylamine as surface modifier, NaOH as mineralizer and reagent grade ZnO. The systematic experiments on the photodegradation of Direct Blue 71 were carried out by changing different effective parameters. The variables in this study were type of nanomaterials synthesized (4 types), nanomaterial dosage (0.4-1.0 g/L), contact time (30-120 min), pH (3-11), and dye concentration (20-100 ppm). The photodegradation efficiency was determined using a UV-Vis spectrophotometer. Determination of total organic carbon (TOC) amount was used to find out mineralization efficiency. Our experimental results revealed that the nanomaterials synthesized had higher efficiency compared with the reagent grade ZnO. The best efficiency was achieved at the following conditions: 1.0 g/L nanomaterials loading, 120 min contact time, pH 5, and photodegradation efficiency from more than 75 up to 99% depending upon the dye concentration.

In situ surface modification of molybdenum-doped organic-inorganic hybrid TiO2 nanoparticles under hydrothermal conditions and treatment of pharmaceutical effluent.

Molybdenum-doped TiO2 organic-inorganic hybrid nanoparticles were synthesized under mild hydrothermal conditions by in situ surface modification using n-butylamine. This was carried out at 150 degrees C at autogeneous pressure over 18 h. n-Butylamine was selected as a surfactant since it produced nanoparticles of the desired size and shape. The products were characterized using powder X-ray diffraction, Fourier transform infrared spectrometry, dynamic light-scattering spectroscopy, UV-Vis spectroscopy and transmission electron microscopy. Chemical oxygen demand was estimated in order to determine the photodegradation efficiency of the molybdenum-doped TiO2 hybrid nanoparticles in the treatment of pharmaceutical effluents. It was found that molybdenum-doped TiO2 hybrid nanoparticles showed higher photocatalytic efficiency than untreated TiO2 nanoparticles.

Porous synthetic hectorite clay-alginate composite beads for effective adsorption of methylene blue dye from aqueous solution.

The present study deals with the preparation and characterization of mesoporous synthetic hectorite (MSH) clay which further encapsulated with Na-alginate for the preparation of mesoporous synthetic hectorite-alginate beads (MSH-AB) where Ca2+ act as a cross-linking agent. The detail characterization of MSH and MSH-AB were carried out by various physicochemical techniques. The thermogravimetric analysis study showed better thermal stability results for MSH-AB. The textural properties results of MSH and MSH-AB showed the high surface area 468, 205m2/g, and the pore volume of 0.34, 0.29cm3/g respectively. The applicability of powder MSH and MSH-AB in wet (W) and dry (D) forms were assessed for the removal of cationic dye, methylene blue (MB) by optimizing various batch adsorption parameters. The Langmuir monolayer adsorption capacity obtained for MSH-AB-W showed significant high adsorption efficacy (i.e., 785.45mgMB/g) compared to the MSH-AB-D (357.14mgMB/g) and powder MSH materials (196.00mgMB/g). The adsorption isotherm studies showed that the Langmuir isotherm model was best suitable for MSH, whereas the Freundlich model was utilised to describe the adsorption behavior of organized hydrogel composite beads. The pseudo-second-order kinetics model was observed best for MB sorption onto MSH, whereas pseudo-first order useful to describe the kinetic behavior of MSH-AB. The regeneration experimental results revealed that MSH-AB-W could be recycled more than six cycles with high MB removal efficiency. Furthermore, the adsorption property of the MSH-AB-W was examined for the binary mixture of MB with other dye solutions such as Methyl Red (MR), Methyl Orange (MO), Alizarine Yellow (AY), and Remazol Brilliant Blue (RBB) to evaluate the selective adsorption efficiency. The MSH composite beads were found potentially suitable as an efficient, selective and recyclable adsorbent for the removal of MB from the aqueous solutions.