Reduction of non-Betalactam Antibiotics COD by Combined Coagulation and Advanced Oxidation Processes.

The present study evaluates the reduction of antibiotic COD from wastewater by combined coagulation and advanced oxidation processes (AOPS). The reduction of Azithromycin COD by combined coagulation and Fenton-like processes reached a maximum 96.9% at a reaction time of 30 min, dosage of ferric chloride 120 mg/L, dosages of Fe0 and H2O2of 0.36mM/L and 0.38 mM/L, respectively. Also, 97.9% of Clarithromycin COD reduction, was achieved at a reaction time of 30 min, dosage of ferric chloride 120 mg/L, dosages of Fe0 and H2O2 of 0.3 mM/L and 0.3mM/L, respectively. The results of kinetic studies were best fitted to the pseudo first order equation. The results showed a higher rate constant value for combined coagulation and Fenton-like processes [(kap = 0.022 min-1 and half-life time of 31.5 min for Azithromycin) and (kap = 0.023 min-1 and half-life time of 30.1 min for Clarithromycin)].

Removal of tetracycline antibiotic from contaminated water media by multi-walled carbon nanotubes: operational variables, kinetics, and equilibrium studies.

Multi-walled carbon nanotubes (MWCNTs) were purified and oxidized by a 4 mol L(-1) mixture of H2SO4:H2O2 and then were used as adsorbent for tetracycline (TC) adsorption from aqueous solutions. The purified MWCNTs were characterized using Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and N2 adsorption/desorption isotherms. The adsorption of TC onto the MWCNT was investigated as a function of the initial pH of the solution, adsorbent dosage, and background electrolyte cations and anions. The results of the one-way analysis of variance (ANOVA) showed that Fe(3+) ion significantly affected and decreased TC adsorption onto the MWCNT (P-value < 0.05), while other studied cations and anions did not affect TC adsorption (P-value>0.05). Nonlinear pseudo-first-order, pseudo-second-order, general order, and Avrami fractionary-order kinetic models were used to investigate the kinetics of TC adsorption. The fractionary-order kinetic model provided the best fit to experimental data. In addition, the adsorption isotherms data were well described by nonlinear equation of the Liu isotherm model with the maximum adsorption capacity of 253.38 mg g(-1). The results of this study indicate that the oxidized MWCNTs can be used as an effective adsorbent for TC removal from aqueous solutions.

The effect of climatic variables and techno-structural factors on the water pollution caused by nicotine leakage from littered cigarette butts.

Nicotine is one of the main pollutants in cigarette smoke that trapped in the filter. Nicotine leakage from cigarette butts is one of the concerns associated with this hazardous waste. In this study, the concentration of nicotine leaked from cigarette butts into the urban environment was investigated under the influence of three parameters including rainfall, density, and the durability of the littered cigarette butt. The leakage of nicotine into the environment was estimated in six scenarios based on the difference in the durability of cigarette butts in the urban environment and the humidity ratio. The results showed that the density of littered cigarette butts was 0.0019-0.294 number/m2. The density of littered cigarette butts in residential land-use was 52.38% lower than commercial land-use. Nicotine leakage from cigarette butts in commercial, residential, and recreational land-uses was 1.1, 0.484, and .0065 mg/m2, respectively. In the studied scenarios, in the best and worst case, 335,070 and 481,950 gr/year of nicotine will leak from the cigarette butt into the water resources. Considering that cigarette butts are a serious source of toxins including nicotine to the environment, control measures are necessary to reduce its density in the urban environment.

The fate of leaked heavy metals in the urban environment under different persistence and precipitation scenarios.

The use of tobacco will lead to the littering of a large number of filters, and the leakage of pollutants from them into the urban environment is a serious concern. The aim of this study was to analyze the leakage of heavy metals from filter and estimate the annual concentration of pollution leakage in different waste routes and different climatic conditions. The results showed that the highest and lowest density of filter in the studied urban environment were 0.51 and 0.01 number/m2, respectively. According to the estimated annual production of 306 million cigarette butts in the studied area, the leakage of the studied metals was estimated to be 401 g. The share of copper, chromium, and cadmium from the total leakage was 67%, 8.3%, and 1.88%, respectively. The leakage of studied metals in rainy conditions was 2.86 times more than sunny conditions. In different scenarios, the minimum and maximum annual leakage of metals were estimated 23,043 and 350,419 mg/year, respectively. Filters are a little but important source of heavy metal emission into the urban environment, the amount of pollution from which is affected by the consumers' behavior and the efficiency of the urban cleaning system. Education on the correct disposal of filters and increasing the efficiency of the urban cleaning system will lead to a reduction in pollution caused by tobacco consumption.

Spatial and temporal variation of CBPI and leakage of heavy metals from cigarette butts into the urban environment.

More than 5 trillion cigarettes are produced in the world every year. This hazardous waste is one of the most important litter in the environment. The purpose of this study was to investigate the density and dispersion of cigarette butts in the urban environment and to estimate the leakage of pollution from it to the environment. For this purpose, the cigarette butt pollution index was used in 14 locations. Observations were made during a year and once a month for each location. The study of the locations was done with the same conditions on weekend and working days. The amount of heavy metal leakage was estimated based on the average weight of cigarette butts and the ratio of metal leakage in different weather conditions. The results showed that the annual average of index for the studied locations was 1.36 (SD 0.11) to 10.6 (SD 1.23). Based on this, 28.5% of the locations were in the low pollution status and 42.8% were in the significant pollution status and worse. On average, the index on weekend decreased by 32.3 percent in all locations, and the average index of the studied locations in spring and summer was 26.2 percent higher than in autumn and winter. The average leakage of heavy metals including chromium, cadmium, zinc, lead, copper, and nickel from littered cigarette butts in commercial, residential, and recreational areas was estimated to be 0.27, 0.079, and 0.17 µg per square meter, respectively. Cigarette butt is one of the most abundant litter in the studied area, which is the source of many pollutants, including heavy metals. This hazardous waste is a serious threat to the urban environment.

The impact of two insecticides on the pollutant cycle and quality of surface and groundwater resources in the irrigated lands of Yasuj, Iran.

The increase in the need for food and agricultural development has led to an increase in the use of insecticides. The use of insecticides leads to air, soil and water pollution. This study investigated the pollutant concentration cycle in the environment by analyzing diazinon and deltamethrin in a river and groundwater sources affected by an agricultural area. The samples were analyzed based on the standard method for insecticides in water using a GC-MS. The results showed that the quality of the surface water affected by the agricultural effluents decreased so that the changes of dissolved oxygen, nitrate, turbidity, TOC, BOD, and COD were 15.2%, 189.6%, 00%, 53%, 176%, and 57.5%, respectively. The concentration of diazinon and deltamethrin in agricultural wastewater was 86 µg/L and 11.62 µg/L. The self-treatment capacity of the river reduced the concentration of diazinon in the distance of 2 km and 15 km by 80.8% and 90.3%, respectively. These conditions were observed for deltamethrin in 74.8% and 96.2%, respectively. Also, the concentration of the two insecticides in water resources has temporal and spatial variation. The difference between the maximum and minimum concentration of diazinon and deltamethrin at different times was 183.5 and 1.73, respectively. The concentration of diazinon and deltamethrin in the downstream groundwater of the studied irrigated area was 0.3-0.7 µg/L, respectively. Although the soil structure and the self-purification capacity of the river caused a significant reduction of insecticides, the remained concentration of these pollutants in underground and surface water resources can still be a health and environmental concern.

Impact of Covid-19 pandemic lockdown on the urban litter and clean environment index.

Changing the level of pollution in the urban environment is one of the consequences of Covid-19. Litter are one of the most important urban pollutants affected by the Covid-19 pandemic. In this research, the pollution level of urban areas during the Covid-19 pandemic was investigated by studying the urban environment. To this end, the protocol of observation and counting was used and litter were studied in two groups including common litter and Covid-19 related litter in Yasuj, Iran. The results were interpreted based on the clean environment index (CEI). The time of observation was selected based on the peak of the disease and the decline in the incidence rate. The results showed that on average, at the peak of the disease, the density of the litter was reduced by 19% compared to the low lockdown related to Covid-19. The CEI on average was 4.76 at the peak of the disease that was interpreted in the clean status, while the CEI on average was 5.94 at the low lockdown related to Covid-19 so interpreted in the moderate status. Among urban land uses, recreational areas with a difference of more than 60% showed the greatest impact caused by Covid-19, while in commercial areas this difference was less than 3%. The effect of Covid-19 related litter on the calculated index was 73% in the worst case and 0.8% in the lowest case. Although Covid-19 decreased the number of litter in urban areas, the emergence of Covid-19 lockdown related litter was a cause for concern and led to increasing the CEI.

Coagulating potential of Iranian oak (Quercus Branti) extract as a natural coagulant in turbidity removal from water.

Because of the presence of tannin in the molecular structure of oak extract, this substance is used as a natural coagulant to remove turbidity from water. The aim of this study was to determine the efficiency of this coagulant alone and in combination with polyaluminium chloride (PACl) in turbidity removal from water under optimal conditions. In this experimental study, Iranian oak extract was prepared by maceration method using ethanol 96% as an extractor. Kaolin was used to prepare synthetic turbid water samples. Using the jar test, the optimum concentrations of oak extract and PACl were determined in various concentrations of initial turbidity and pH. Moreover, the central composite design (CCD) method was utilized to design experiments and RSM was applied for analyzing the obtained results. Optimum concentrations of oak extract and PACl were 62.6 mg/L and 52.6 mg/L, respectively. An increase in initial turbidity and pH led to an increase in turbidity removal by the two coagulants. The efficiency of turbidity removal by oak extract and PACl was 63.5% and 66.5%, respectively. The simultaneous application of oak extract and polyaluminium chloride increased removal efficiency (85%) and reduced the total organic carbon concentration (TOC) in water (42.3%). The results showed that the simultaneous application of Iranian oak extract and polyaluminium chloride had an acceptable performance in removing turbidity from water.

A comparative study of hospital admissions for respiratory diseases during normal and dusty days in Iran.

During the last century, most of people around the world moved from communicable to non-communicable diseases, mainly due to air pollution. Air pollutants and dust storm increase risk of morbidity, for cardiovascular and respiratory diseases, and increase the number of deaths. The city of Ahvaz is considered as the focal point of air pollution and dust storm in Iran. The aim of this study was to determine the number of Hospital Admission Respiratory Disease (HARD) including asthma attacks, acute bronchitis and chronic obstructive pulmonary disease attributed to PM10 by a descriptive study during normal and dust event days in Ahvaz during the time period 2010-2012. The hourly PM10 data was collected from the Iranian Environmental Protection Agency and Razi hospital. The annual PM10 mean concentrations reached 282, 288 and 278 µg/m3 in 2010, 2011 and 2012, respectively. The number of HARD attributed to PM10 was 1438, 1945 and 1393 people, respectively, and the highest number of daily admissions was attributed to the highest daily PM10 concentration in Ahvaz. The average number of daily HARD during dusty days was higher than normal days, and a significant positive correlation, between the number of hospital admissions and dusty days, was found. Dust had significant impact on HARD in Ahvaz.