Oily wastewaters treatment using Pseudomonas sp. isolated from the compost fertilizer

BACKGROUND: Discharging the oily wastewater in the environment causes serious problems, because of the oil compounds and organic materials presence. Applying biological methods using the lipase enzyme producer microorganisms can be an appropriate choice for treatment of these wastewaters. The aim of this study is to treat those oil wastewaters having high concentration of oil by applying lipase enzyme producer bacteria. MATERIALS AND METHODS: Oil concentration measurement was conducted using the standard method of gravimetric and the wastewater under study was synthetically made and contained olive, canola and sunflower oil. The strain used in this study was Pseudomonas strain isolated from compost fertilizer. The oil under study had concentration of 1.5 to 22 g/l. RESULTS: The oil removal amount in concentrations lower than 8.4 g/l was over 95 ± 1.5%. Increase of the oil's concentration to 22 g/l decreases the amount of removal in retention time of 44 hours to 85 ± 2.5%. The best yield of removing this strain in retention time of 44 hours and temperature of 30°C was achieved using Ammonium Nitrate as the nitrogen resource which yield was about 95 percent. CONCLUSION: The findings of the research showed that Pseudomonas bacteria isolated from the compost fertilizer can degrade high concentration oils

Leaching Zn, Cd, Pb, and Cu from Wastewater Sludge Using Fenton Process

Background: High amount of heavy metals in sludge is one of the major obstacles to its use on farms. The present study aimed to investigate the possibility of leaching heavy metals from wastewater sludge by Fenton method and determine the optimum level of parameters, such as iron, hydrogen peroxide, time, and pH for Fenton reaction. Methods: The effects of various parameters, such as pH (2-9), hydrogen peroxide concentration (0.5-6 g/l), Fe concentration (0.5-4 g/l), and leaching time (5-60 min), were studied. Results: The results showed that the optimal condition for leaching of heavy metals occurred at pH of 2-3, hydrogen peroxide concentration of 3 g/l, iron concentration of 2 g/l, and leaching time of 15 min. Under these optimal conditions, 92% of Zn, 100% of Cd, 100% of Pb, and 80% of Cu were leached from the wastewater sludge. Conclusions: Fenton method can leach heavy metals from wastewater sludge through decomposition of organic materials at H2O2/Fe ratio of 1.5:2

Evaluation of Hospital Waste Management and Its Categorization in Valiasr Hospital, Mamasani Nurabad City, Fars

The evaluation of both qualitative and quantitative factors regarding biomedical waste can help remedy the shortcomings of the current hospital waste management (HWM) system. The present study used a questionnaire and a weighing operation to investigate the perceived quality of HWM and the quantity of biomedical waste in Valiasr hospital, Nurabad district, Mamasani county, Iran, from July to September 2013. For 21 days, at the end of each shift, all hospital waste was weighed using scales. In addition, a 21-item questionnaire concerning perceptions of the quality of waste division, collection, storage, and transportation was administered to 40 hospital employees. The results of the weighing operation revealed that the hospital generated 417.99 kg of waste per bed per day (kg/bed-day). Considering that there are 96 beds actively used in the hospital, the average kg/bed-day of waste generated was 2.32 kg/bed-day of infectious waste, 0.03 kg/bed-day of sharps, and 2 kg/bed-day of household waste. The highest amount of infectious waste was generated in the emergency unit and the second highest in the operating rooms. In addition, analysis of questionnaire responses showed that most participants classified HWM activities as good, including waste division (65%), collection and transport to temporary waste storage (77.5%), and transport to the disposal zone (80%). Improper division of wastes by employees and visitors increased the volume of waste identified as infectious by mistakenly adding non-infectious waste to the bags of infectious waste. To reduce the volume of waste identified as infectious, division of wastes must be properly implemented and scrupulously maintained

Stabilization and Dewatering of Wastewater Treatment Plants Sludge Using the Fenton Process

Wastewater sludge typically contains large amounts of water and organic materials; therefore, its stabilization and dewatering is of particular importance. In this study, Fenton oxidation process is used for stabilization and dewatering of sludge in the output of a wastewater treatment plant. To evaluate the sludge stabilization and dewatering, specific resistance to filtration (SRF), volatile organic compounds (VSS), total suspended solids (TSS), soluble chemical oxygen demand (SCOD) and heterotrophic bacteria were measured. During the experiment, the optimal values of various parameters such as pH (2-9), hydrogen peroxide (0.015- 0.18mol/L), Fe2+ (0.008- 0.1mol/L) and time (5 - 60 minutes) for optimum sludge dewatering and stabilization were investigated. The results showed that the highest percentages of SRF reduction and removal rates of SCOD, VSS and TSS were 99.48, 61, 42, and 41 percent respectively. These results were obtained in optimum pH 5, 0.05 mol/l Fe2+, 0.12 mol/l hydrogen peroxide, and the retention time of 15 minutes. The removal rate of heterotrophic bacteria increased with increasing dose of hydrogen peroxide, so that a removal rate of 84 percent was observed at a dose of 0.18 mol/l. In general, Fenton process can reduce volatile organic materials and chemical oxygen demand of the sludge resulting in its significant stabilization and dewatering. In general, Fenton process can reduce volatile organic materials and chemical oxygen demand of the sludge resulting in its significant stabilization and dewatering

Application of montmorillonite/octadecylamine nanoparticles in the removal of textile dye from aqueous solutions: Modeling, kinetic, and equilibrium studies

In the study, the proliferation of industries has been associated with an increase in the production of industrial wastewater and subsequent environmental pollution, wherein dyes emerge as prominent pollutants. The characteristics of nanoclay modified with octadecylamine, were elucidated throughvarious techniques, including Field Emission Scanning Electron Microscopy/Energy Dispersive Spectroscopy (FE-SEM/EDS), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), X-ray Diffraction (XRD), and Brunauer-Emmett-Teller Surface Area Analysis (BET). The research delved into the impact of variables such as pH, initial dye concentration, adsorbent dose, temperature, and ultrasonication time on the removal of Acid Black 1 (AB1) through an ultrasonic process, employing a central composite design (CCD). Optimal conditions for the adsorption process were determined: pH at 5.46, adsorbent mass at 4 mg/30 mL, initial dye concentration at 20 mg/L, ultrasound time at 20 min, and temperature at 50 °C, resulting in a remarkable 96.49% adsorption efficiency. The fitting of experimental equilibrium data to different isotherm models, including Langmuir, Freundlich, and Temkin, indicated thatthe Freundlich model was the most suitable. Analysis of the adsorption data with various kinetic models such as pseudo-first and second-order models, and intraparticle diffusion models, revealed the applicability of the second-order equation model. A thermodynamic study unveiled that the adsorption process was spontaneous and endothermic. In conclusion, the study highlights the significant capability ofmontmorillonite nanoclay modified with octadecylamine in removing AB1 dye, rendering it a viable option for wastewater treatment

Removal of Diclofenac Sodium from Wastewater in Microbial Fuel Cell by Anode Modified with MnCo₂O₄

Microbial fuel cell (MFC) with a modified anode is one of the new methods to increase MFC efficiency. This study synthesized an anode modified with cobalt manganese oxide (MnCo2O4@CF) on carbon felt (CF) by easy hydrothermal method and binder-free. Chemical oxygen demand (COD) was measured with and without diclofenac (DCF). According to SEM results, MnCo2O4 was uniformly dispersed on the anode electrode surface. Moreover, the maximum power density in COD (1000 mg/L), 48 h. condition without DCF (726 mA/m2) was 165 ± 0.012 mW/m2 and with DCF concentration of 20 mg/L, it was 308 ± 0.013 mW/m2 (992 mA/m2). In addition, in the presence of 10 mg/L DCF concentration, the maximum COD removal efficiency was 82% ± 1.93 at 48 h. COD removal efficiency without DCF was 94.67% ± 0.02 at 72 h. After 72 h, the maximum removal efficiency of COD and DCF in the carbon anode was 41% ± 1.15 and 9.5% ± 0.23, respectively. Moreover, the maximum DCF removal efficiency using a MnCo2O4 anode was 56% ± 0.55, at 48 h; the initial COD concentration was 500 mg/L, and the DCF concentration was 20 mg/L. This research showed that coating the anode with MnCo2O4 could lead to the increased growth of microorganisms on the surface of the anode, decreased load transfer resistance, increased power density, and more removal of COD and DCF. As a result, the performance of fuel cells with modified anode and removal of DCF increased compared to anode with CF-MFC. Thus, the performance of fuel cells with modified anode and removal of DCF increased compared to anode with CF-MFC

Synthesize of heterostructure TiO2 by simultaneous doping of double silver and phosphate to degradation of methylene blue under visible light

Abstract Photocatalysts show great potential as compounds for restoring contaminated water and wastewater resources. The study aims to synthesize a composite with high photocatalytic potential under visible light to photodegrade the organic pollutants. Ag/Ag3PO4@ TiO2 were synthesized by doping Ag and Ag3PO4 on TiO2. The composite was characterized using X-ray diffraction analysis (XRD), diffuse reflectance spectroscopy, Field emission scanning electron microscopy, and Energy-dispersive X-ray spectroscopy analyses, and its photodegradation ability was investigated by methylene blue. Utilization of pure TiO2 yielded a removal efficiency that was merely half of the efficiency achieved when using modified particles, owing to the reduction of TiO2 s band gap from 3.2 to 1.94 eV. In addition to its enhanced photocatalytic performance under visible light, the synthesized Ag/Ag3PO4@TiO2 photocatalyst demonstrated remarkable efficiency in removing dyes such as methylene blue from aqueous solutions. The removal efficiency at pH less than 7 in 50 ppm methylene blue solution using 3 g/l photocatalyst over 45 min visible light irradiation was approximately 90 percent. Under sunlight, photocatalytic reactions exhibited an efficiency of over 95 percent within 45 min. It can be concluded that the simultaneous introduction of metallic (Ag) and nonmetallic (PO4 3−) dopants significantly increases the efficiency of electron–hole recombination suppression in the photocatalyst and also decreases the band gap

Removal of Diclofenac Sodium from Wastewater in Microbial Fuel Cell by Anode Modified with MnCo2O4

Microbial fuel cell (MFC) with a modified anode is one of the new methods to increase MFC efficiency. This study synthesized an anode modified with cobalt manganese oxide (MnCo2O4@CF) on carbon felt (CF) by easy hydrothermal method and binder-free. Chemical oxygen demand (COD) was measured with and without diclofenac (DCF). According to SEM results, MnCo2O4 was uniformly dispersed on the anode electrode surface. Moreover, the maximum power density in COD (1000 mg/L), 48 h. condition without DCF (726 mA/m2) was 165 ± 0.012 mW/m2 and with DCF concentration of 20 mg/L, it was 308 ± 0.013 mW/m2 (992 mA/m2). In addition, in the presence of 10 mg/L DCF concentration, the maximum COD removal efficiency was 82% ± 1.93 at 48 h. COD removal efficiency without DCF was 94.67% ± 0.02 at 72 h. After 72 h, the maximum removal efficiency of COD and DCF in the carbon anode was 41% ± 1.15 and 9.5% ± 0.23, respectively. Moreover, the maximum DCF removal efficiency using a MnCo2O4 anode was 56% ± 0.55, at 48 h; the initial COD concentration was 500 mg/L, and the DCF concentration was 20 mg/L. This research showed that coating the anode with MnCo2O4 could lead to the increased growth of microorganisms on the surface of the anode, decreased load transfer resistance, increased power density, and more removal of COD and DCF. As a result, the performance of fuel cells with modified anode and removal of DCF increased compared to anode with CF-MFC. Thus, the performance of fuel cells with modified anode and removal of DCF increased compared to anode with CF-MFC

The effects of short-term exposure to selected heavy metals carried by airborne fine particles on neural biomarkers during dust storms

International audienceThis study aimed to investigate the effects of short-term ambient environmental exposure to fine particles and heavy metals (HMs) on neural biomarkers of people within dust storm conditions. From 44 healthy volunteers, who had already been identified, blood and urine samples were taken 24 h before the dust storm. Their blood and urine samples were taken 24 h after exposure. Vanillylmandelic acid (VMA) and homovanillic acid (HVA) were measured as urine markers, while neuron-specific enolase (NSE), cortisol, S100 beta, and white blood cells (WBCs) were tracked as blood markers. Eleven HMs (Fe, Mn, Zn, Cr, Co, Al, Ni, Pb, Cd, As, and Cu) correlated with fine particles were measured in both normal and dusty days. The mean concentration of fine particles on normal and dusty days was 60.21 and 238.8 mu g m(-3), respectively. The mean value of the post-exposure NSE and S100 beta was 0.59 ng/L-1 (p = 0.002) and 5.61 ng/L-1 (p <= 0.004) higher than that of the pre-exposure respectively. However, the average blood cortisol level decreased by 3.12 ng mL(-1) after exposure compared to before it. The mean post-exposure HVA was 0.59 mg g(-1) creatinine (CRT) higher than the mean pre-exposure HVA value, which was statistically significant (p = 0.000). Ni (r = 0.6), Cd (r = 0.85), and Fe (r = 0.7) caused an increase in the NSE biomarker. Metal compounds and toxicity of fine particles in dust storms may affect biological markers related to nervous system function and systemic physiological stress