Environmental Health Engineering and Management Journal
Volume:5 Issue: 4, Autumn 2018

Drugs, especially antibiotics, are one of the serious problems of modern life and the main pollution sources of the environment, especially in the last decade, which are harmful to human health and environment. The aim of this study was to investigate the removal of penicillin G from aqueous solutions using single-walled and multi-walled carbon nanotubes. In this study, the effect of different parameters including pH (3, 5, 7, 9, and 11), initial concentration of pollutant (50, 100, 150, and 200 mg/l), absorbent dose (0.25, 0.5, 0.75, and 1 g/L), mixing speed (0, 100, 200, and 300 rpm), and temperature (10, 15, 25, 35, 45°C) were investigated. The Langmuir, Freundlich, Temkin, BET, Dubinin-Radushkevich isotherms and adsorption kinetics of the first- and second-order equations were determined. The results showed that the efficiency of single-walled and multi-walled carbon nanotubes in the removal of penicillin G was 68.25% and 56.37%, respectively, and adsorption capacity of the nanotubes was 141 mg/g and 119 mg/g at initial concentration of 50 mg/l and pH=5 with adsorption dose of 0.8 g/L for 105 minutes at 300 rpm and temperature of 10°C from aqueous solutions. Also, it was revealed that the adsorption process had the highest correlation with the Langmuir model and secondorder kinetics, and the maximum adsorption capacity based on Langmuir model was 373.80 mg/g. According to the results, it was found that single-walled and multi-walled carbon nanotubes can be used as effective absorbents in the removal of penicillin G from aqueous solutions.

Dye and colored materials cause health risks in water and therefore, must be removed from water supplies and wastewater. The aim of this study was to evaluate the effectiveness of the third generation poly(amidoamine) (PAMAM) and poly (propylene imine) dendrimers (PPI-G3) in the removal of reactive blue 19 (RB19) dye from aqueous solutions and determine the optimum conditions for the removal. This study was performed in a laboratory and batch scale. In this study, synthetic wastewater was examined with three different concentrations of RB19 (25, 50, and 100 mg/L), different pHs (3, 7, and 10), various amounts of dendrimer (0.4, 0.8, 1.2, and 1.6 g/L), and at different times (15, 30, and 60 minutes) during the adsorption process. The remaining amount of dye was measured by spectrophotometer at 592 nm wavelength. Langmuir and Freundlich isotherms were also tested. The results showed that by increasing the reaction time and adsorbent dosage, the rate of dye removal increased while by increasing the initial dye concentration and pH, the dye removal efficiency was significantly decreased. In this study, with increase of pH from 3 to 10, dye removal efficiency at a concentration of 25 mg/L, decreased from 72% to 20% and 88% to 17% by PAMAM and PPI dendrimers, respectively. Excel software was used for data analysis. Both adsorbents had a good dye removal efficiency, but PPI dendrimer was more effective in removing RB19. Adsorption data followed the Langmuir isotherm.

The most commonly used insecticide by 99.8% farmers in West Sumatra, is chlorpyrifos which contains organophosphates. Chlorpyrifos is used to kill insects and other pests and works as the contact poison, gastric toxins, and inhalation. It is very useful for farmers in keeping the plants such as corn, citrus, peanuts, and so forth. Chlorpyrifos can enter the water body with direct application to control pests or indirectly through either spraying or washing during high rainfall in spray applications for plant leaves. Chlorpyrifos is also used in farming in the region of Twin Lakes (Diatas Lake and Dibawah Lake), West Sumatra, Indonesia. One of the most important fish that is cultivated in this region is Nile tilapia (Oreochromis niloticus). The acute toxicity (LC50-96 h) of chlorpyrifos for Nile tilapia in studies was 0.076 mg/L. Sublethal concentrations used for the studies were one-seventh (0.011 mg/L) and one-fourteenth (0.005 mg/L) of the LC50-96 h. The test animal was exposed to the both sublethal concentrations for 1, 7 and 14 days. Behavioral responses were studied in the experimental periods. Tilapia that exposed chlorpyrifos exposure was exhibited irregular body movements, gills and fins motion, mucus secretion, breathing at the surface, and anal excretion. It was revealed that the longer the exposure time, the more visible behavioral changes in fish, as well as the concentration variations, it means that the higher the concentration, the more visible changes in physiological behavior of fish. Correlation values (R) were was 0.75–0.99. These behavioral responses can be used as a tool in biomonitoring program to monitor ecotoxicity risk of chlorpyrifos to the test species, especially in the region of Twin Lakes, West Sumatra, Indonesia.

Today, the effects of environmental pollution on human life and human needs, which reduces the level of community health caused by traffic noise in large cities, are clearly visible by creating irritation and pathogenic conditions. The aim of this study was to assess the risk of noise pollution resulted from central traffic in Shiraz by analyzing its indicators and related components. By specifying the high traffic jam in Shiraz, the sound and its frequency in 156 points of the city were analyzed using a sound analyzer (Tes-1358C model). The sound pressure levels (LA and LP) and the one and one-third octave band were continuously measured in A and C networks. Then, data were extracted and analyzed using Excel 2016 and Minitab 18.1. Eventually, phon and sone indexes were calculated for the heavy traffic jam in some of the central streets of Shiraz and the results were statistically calculated and their charts were prepared with comfort disturbance ranges. The highest harmful frequency of traffic in Shiraz was 50 Hz and 83.3 dB. The sound pressure level ranged from 70 to 92.7 dB in network A and 87.8 dB in network C. The maximum sound level was 87 phon and the maximum sone was 26 at 14 stations. According to the results, the sound pressure levels exceeded the environmental standards of Iran and the values of phon and sone were higher than the standard of comfort at night and day.

This retrospective study aimed to investigate the physicochemical properties of drinking water sources in Ethiopia and compare the water quality with the health-based target. For this purpose, the water quality database of Ethiopian Public Health Institute (EPHI) from 2010 to 2016 was used. The concentration and other properties of the water samples were analyzed according to the Standard Methods of Water and Wastewater analysis. Quality control and quality assurance were applied in all stages following our laboratory standard operation procedures (SOPs). The concentration of the selected parameters varied based on the type of water sources. The mean concentration of turbidity was higher in spring water (21.3 NTU) compared to tap (12.6 NTU) and well (3.9 NTU) water sources. The mean concentration of total dissolved solids (TDS), electrical conductivity (EC), sodium (Na+), and sulfate (SO4-2) was found to be higher in spring water sources than tap and well water sources. Comparably, the concentration of hardness, calcium, and magnesium was found to be higher in well water sources than spring and tap water sources. The bivariate analysis indicated that out of 845 analyzed water samples, more than 50% of the samples from Oromia region had turbidity, pH, TDS, hardness, Ca++, K+, and Na+ within an acceptable limit. In addition, the logistic regression analysis showed that water quality parameters were strongly associated with the type of water sources and regional administration at P < 0.05. More than 80% of the samples analyzed from drinking water sources were in agreement with WHO guidelines and national standards. However, the remaining 20% specifically, pH (25%), calcium (20%), hardness (18.1%), TDS (15.5%), and turbidity (13.3%) analyzed from improved water sources did not comply with these recommendations. Due to objectionable or unpleasant taste, people may force to look for alternative unprotected water sources that lead to health concerns.

Spent caustic contains noxious components such as sulfide species and also high chemical oxygen demand content (COD). Oxidation of these materials to caustic and sulfate species is mostly the rate-controlling step within catalytic oxidation of spent caustic. In this study, the kinetics of catalytic oxidation of spent caustic and the regeneration methodology of the sulfidic spent caustic were investigated. The kinetics of catalytic oxidation of spent caustic was studied in the presence of a heterogeneous catalyst. The developed mathematical model was verified via the batch bubble column reactor. The elementary and non-elementary models based on the genetic algorithm were used to obtain the rate coefficient and kinetic order. The experiments were carried out at various conditions. The results indicated that the error of objective function of the non-elementary and elementary models was 3.01% and 134.96%, respectively. According to the results, the non-elementary model had rational outcome compared to the elementary one. Also, non-elemental model is more concordance with experimental results.

Electro-oxidation is developed as an electrochemical method to overcome the problems of the conventional decolorization technologies and is an appropriate alternative for the treatment of colored wastewater from various industries. The purpose of this study was to evaluate the efficiency of the electrochemical oxidation process in removal of chemical oxygen demand (COD) and Acid Red 18 (AR18) dye from aqueous solutions. In this research, a laboratory scale of electro-coagulation reactor for the treatment of synthetic wastewater was made and studied. The effects of different variables including pH, current density, dye concentration, and electrolysis time were investigated. The experiment steps were designed by Design-Expert 10 software using the selected variables. Finally, the dye and COD analysis was performed by spectrophotometer. The optimization was performed using Taguchi fractional factorial design during the removal of dye and COD. Maximum removal of dye (89%) and COD (72.2%) were obtained at pH=3, current density=20 mA/cm2, initial dye concentration=100 mg/L, and reaction time=45 min. ANOVA test showed a significant relationship between statistical model and test data. Also, the results indicate that the distribution of the residues of the model was normal. By designing experiments through Taguchi method, the removal process will be optimized and by decreasing the number of experiments, the optimal conditions for pollutant removal will be prepared. The results suggest that the Electro-oxidation system is a very suitable technique for the enhancement of wastewater treatment.

Due to the adverse effects of artificial preservatives on food and its harmful effects on human health, researchers have been considering replacing these materials with natural substances. In this study, the effect of pomegranate peel extract (PPE) on the stability and antifungal activity of the walnut kernel was studied. The pomegranate peel was extracted by the solvent and water-solvent method. The extracted sap was evaluated using the antioxidant assay by 2,2-diphenylpicrylhydrazyl (DPPH) assay. The results showed that the extracted sap had 40.11 mg/g dry phenol and 47.27% free radicals scavenging. Four concentrations (0%, 2%, 6%, and 10%) of pomegranate liquid extract were prepared and studied for 90 days for the walnut kernel coating. Walnut kernels were coated on days 1, 15, 30, 60, and 90, and examined for moisture, acidity, peroxide, conjugated diene, and anisidine tests. Data were analyzed using SPSS version 21. By increasing the extract concentration from 2 to 10%, the stability of the walnut kernel during storage was increased. Acidity in the samples with 10% PPE coating, decreased from 0.18 to 0.11 on the first day until the 15th day, and increased to 0.48 from day 15 to 90. The results showed that the moisture content and acidity increased with increasing the extract concentration. By increasing the extract concentration up to 10%, the sustainability indices, including peroxide, anisidine, and conjugated diene were significantly decreased. At 90 days, by increasing the concentration of pomegranate extract from 2% to 10%, the count of molds and yeasts was reduced from 3.59 to 2.29 CFU/g. The count of molds and yeasts in the uncoated samples was 5.81 CFU/g. According to the results, PPE can increase the stability and antifungal activity of walnut, therefore, the health quality of the product increases.