Tracking of chloramphenicol, erythromycin, and sulfamethoxazole antibiotic-resistant bacteria from untreated wastewater effluents to receiving river

Background: The aim of this study was to investigate the frequency and type of bacteria resistant to chloramphenicol (CHL), erythromycin (E), and sulfamethoxazole (SXT) antibiotics from untreated wastewater effluents to receiving river. Methods: In total, 32 samples were taken from eight sites located in the raw wastewater to the downstream of the receiving Ghotor river in Khoy city. Resistant microorganisms were studied through modified HPC method and CLSI standards. Different and specific colonies were selected and re-cultured in R2A culture medium and enough colonies were used for DNA extraction. Bacterial 16sr RNA target gene was amplified and sequenced. Pseudomonas sp., Comamonas sp., and Thiobacillus sp. were predominant bacterial species identified in water samples. Also, antibiotic-resistant genes (ARGs) including sul1, ermB, and cmlA1 were tracked by PCR. Results: The average total number of antibiotic-resistant bacteria (ARB) increased in the downstream (2.4×102 to 2.6×104 CFU/100 mL). The comparison of the results related to the river’s upstream and downstream also indicated a significant difference between ARB and ARGs contents (P<0.05). The average number of bacteria resistant to SXT, E, and CHL antibiotics was obtained to be 2.3×104, 2.3×104, and 3.4×104 CFU/mL, respectively. Finally, the evaluation of water revealed that only the aeration lagoon was able to decline the number of CHL-resistant bacteria (88.9%) while this process increased the number of SXT- (51%) and E- (16%) resistant bacteria. The lowest and highest percentages of the identified genes were related to ermB (12.5%) and sul1 (81.25%), respectively. Conclusion: According to the results, wastewaters play an important role in releasing ARB and their antibiotic resistance genes to downstream of Ghotor rivers in Khoy city. Keywords: Heterotrophic bacteria, Sulfamethoxazole, Chloramphenicol, Erythromycin, Polymerase chain reaction, Wastewater, River

Effect of Medicinal Smokes on Reduction of Fungal Indoor Air Contamination

Introduction: As far as application of chemicals as disinfectants may have side effects on human health and causes drug resistance, the topic of herbal and natural products has been investigated in recent researches. Nevertheless, application of medicinal smokes in the treatment of many diseases, including bacterial and infectious diseases has long been popular in Iran. Smoke from the burning of Peganumharmala (Espand) and female donkey dung (Anbarnasa) are among these smokes which effects on ambient air fungi was investigated in the current study. Materials and Methods: In this analytical research, the smoking was conducted with different masses of Espand and Anbarnasa in the room space. Before and after smoking, air fungal sampling was performed with Anderson method. After three to five days, the composed fungal colonies were counted. Data were analyzed through the SPSS Software (Vs. 18) and Microsoft Excel (2007). Results: The indoor fungal removal percent by Espand smoke in 1, 3, and 5 minutes after smoking were 52.75 %, 64.72 %, and 77.28 %, respectively; and for the Anbarnasa smoke at these times were 54.6 %, 59.4 %, and 74 %. Increase in smoking time caused a significant increase (p < 0.05( in fungi removal, but change in the mass and the kind of smoking matter (Espand or Anbarnasa) did not cause any significant change in the removal. Conclusion: Smoking with Espand and Anbarnasa as well as duration of smoking can decrease the building's ambient air fungi burden significantly. Of course it is better to perform smoking in enclosed spaces especially in toilets and without the presence of the person

Cadmium Biosorption in a Batch Reactor Using Excess Municipal Sludge Powder

This study was conducted to investighate the adsorption of Cadmium from aqueous solutions by using the powder of excess sludge (biosolid) from municipal wastewater, at 24 to 26°C, a pH value of 2 to 6, over a contact time of 5-420 minutes, and at 50 to 300 rpm stirring rate in a batch reactor on the laboratory scale. The pretreatment of biosolids consisted of dewatering, grinding, and grainsizing with sieves (mesh dimensions between 50 and 120). According to the results, the best conditions for biosolids to adsorb Cadmium was pH=4, 120 minutes of contact time, and a stirring rate of 200 rpm. Cadmium adsorption kinetics followed the pseudo second order model. Maximum equilibrium adsorption was observed after two hours. The adsorption isotherm was in accordance with the Langmuir model. Maximum Cadmium adsorption capacity of biosolids (qmax) was estimated at 0.38 m-mol/g of dry biosolid (41.5 mg/g) and the Langmuir constant (kd) was found to be 0.1044 m-mol/lit (11.37 mg/lit)

Data on emerging sulfur dioxide in the emission of natural gas heater in winter

Natural gas is a kind of fuel that is used in various heating systems for combustion processes. Combustion of natural gas produce such air pollutants as CO2, NOx, SOx, PM, CO, and HC. During cold days, total gas consumption in Iran goes up. Thus, in these days it is likely to make some changes in gas properties that can affect the emissions from gas heaters. Portable flue gas analyzer (LANCOM III) was used for, SO2, NOX, and CXHY measurement from December 2012 to April 2013. Data show that emissions of pollutants from the gas heater were different during the cold seasons. On colder days, total gas consumption in the country increased, SO2 emerged in heater stack, and the concentration of hydrocarbons (CXHY) significantly increased as well. This emergence could be attributed to the changes in gas properties in the colder days. In these days, the transient flow and high changes of speed and pressure in the gas pipes could lead to release of some deposited sulfur in gas flow. Therefore, sulfur dioxide will be generated in the combustion process. Keywords: Natural gas heater, Air pollution, SO2, Cold day

Fluoride Content of Bottled Drinking Water Available in North West of Iran

Background: Consumption of bottled waters has received popularity and more acceptances. Fluoride is necessary for human life. But high levels of fluoride can cause some problems for human health such as Fluorosis and teeth and bones problems. The aim of this study is measure the fluoride content in bottled waters consumed in North West of Iran and comparison with the amount listed on their labels and with the drinking water standards. Methods: In this study, 10 brands of bottled water were sampled from markets over the two seasons randomly. Samples were analyzed for fluoride using Ion Chromatography (IC) method. Results: Results showed that fluoride concentration in different brands had a significant difference (P <0.05). The concentration of fluoride in samples ranged between 0.04 and 0.32 mg/L. Among analyzed selected brands four brands were observed significant differences with the measured values. Conclusion: &nbsp;Totally the measured values didn&rsquo;t match with the values declared on the labels (Reliability coefficient <0). It was revealed that fluoride concentration in all brands was less than the lower range of Iranian national standard (0.7-1.2 mg/lit)

Trends of BTEX in the central urban area of Iran: A preliminary study of photochemical ozone pollution and health risk assessment

The Environmental Protection Agency (USEPA) has identified Benzene, Toluene, Ethylbenzene, and Xylene (BTEX) as hazardous air pollutants. In this study, BTEX sampling was conducted at 20 sites during summer 2015 and winter 2016 in Yazd. Concentrations of BTEX were analyzed using a gas chromatograph with a flame ionization detector (GC-FID). In addition, ozone formation potential (OFP) and the health risks of BTEX were calculated. Spatial mapping was accomplished using the Kriging method. The obtained concentrations of total BTEX ranged from 8 to 560 μg/m3. The highest average individual values belonged to toluene and xylene (38 ± 42 and 41 ± 45 μg/m3, respectively). Seasonal variation showed a downward trend from summer to winter. The peak BTEX emissions occurred in the evenings, due to rush hour traffic and meteorological factors. Spatial analysis showed that the maximum levels of BTEX occurred on high traffic roads or near fuel stations. Significant correlation coefficients between benzene and other BTEX compounds revealed that BTEX were emitted from main sources including gasoline vehicles and stations. The mean ratio of toluene/benzene (T/B) in summer (1.8) was more than winter (1.4). The seasonal changes in T/B ratio possibly were attributed to photochemistry, meteorology, and emission aspects. The OFP values were 720 ± 729 and 375 ± 319 μg/m3 in summer and winter, respectively. OFPs, ranked maximum to minimum, were as follows: xylene > toluene > ethylbenzene > benzene. Although the values of the non-cancer risk of BTEX were under permissible recommended level, a cancer risk still exists because of high values of airborne benzene