Predicting the Performance of Gorgan Wastewater Treatment Plant Using ANN-GA, CANFIS, and ANN Models

A reliable model for any wastewater treatment plant (WWTP) is essential to predict its performance and form a basis for controlling the operation of the process. This would minimize the operation costs and assess the stability of environmental balance. This study applied artificial neural network-genetic algorithm (ANN-GA) and co-active neuro-fuzzy logic inference system (CANFIS) in comparison with ANN for predicting the performance of WWTP. The result indicated that the GA produces more accurate results than fuzzy logic technique. It was found that GA components increased the ANN ability in predicting WWTP performance. The normalized root mean square error (NRMSE) for ANN-GA in predicting chemical oxygen demand (COD), total suspended solids (TSS) and biochemical oxygen demand (BOD) were 0.15, 0.19 and 0.15, respectively. The corresponding correlation coefficients were 0.891, 0.930 and 0.890, respectively. Comparing these results with other studies showed that despite the slightly lower performance of the current model, its requirement for a lower number of input parameters can save the extra cost of sampling

Adsorptive Removal of Methylene Blue in Aqueous Solutions Through Raw and Modified Cantaloupe Peel Wastes: Kinetic and Isotherm Study

Since large amounts of agricultural wastes are produced in Iran and these wastes have lignocellulosic nature, the current study was performed to survey the adsorption performance of methylene blue dye from aqueous solutions by means of raw and modified cantaloupe peel. The adsorbents used were characterized using techniques like scanning electron microscope (SEM), as well as Fourier transform infrared spectroscopy (FTIR). In this study, the effects of a few key variables including pH, reaction time, dye concentration, adsorbent dosage and temperature on the adsorption performance were investigated. Optimum values were attained at 0.04 and 0.08 g doses of modified and raw cantaloupe peel, pH of 7 after mixing for 120 and 90 minutes for raw and modified cantaloupe peel, respectively. The equilibrium information was fitted to the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich equations and the respective data for all models were tested. An increase in adsorbent dose and temperature caused the efficiency to rise. The mechanism and rate of adsorption were ascertained by analyzing the experimental data at various contact times according to traditional kinetic equations: pseudo-first-order and second order, Elovich, and intra-particle diffusion. The findings illustrated that the data accorded closely with the pseudo-second-order model. Moreover, it was found that these wastes can be applied to remove environmental pollutants, particularly methylene blue dye

Effective scale-up of oily sludge bioremediation from a culture-based medium to a two-phase composting system using an isolated hydrocarbon-degrading bacterium: effect of two-step bioaugmentation

The scale-up feasibility of oily sludge (OS) biodegradation from a culture-based medium to a new two-stage composting process bioaugmentated with an indigenous isolated strain was surveyed. First, the bacterial strain (Enterobacter hormaechei strain KA6) was isolated from OS, and then its ability in biomass production and oil degradation in culture-based medium was evaluated. Finally, the strain was used for bioaugmentation in composting reactors which included four in-vessel experiments with the initial total petroleum hydrocarbon (TPHs) concentrations between 10 and 30 g kg-1. The strain was added twice to the composting reactors which lasted 16 weeks including the primary composting stage (PCS) (first inoculation) and the secondary composting stage (SCS) (second inoculation). It was observed that the strain degraded 58.67, 74.79, 45.33, 10.66, and 5.92% of 1, 2, 3, 4, and 5% oil concentrations, respectively, in culture-based medium during 7 days. Regarding OS bioremediation in the composting experiments, a total TPH removal rate of 65.83–81.50% was also reached after the two-stage duration of 16 weeks. Due to the second bioaugmentation stage, the SCS showed higher TPH removal efficiency than the PCS. The study confirmed the effectiveness of the scaling-up of a culture-based medium to a composting process for treating OS

Biodegradation of heavy oily sludge by a two-step inoculation composting process using synergistic effect of indigenous isolated bacteria

The impact of two-step inoculation of indigenous strains and their synergistic effect in the scaling-up of petroleum hydrocarbons biodegradation from a mineral-based medium (MBM) to a two-phase composting process were investigated. After isolating the strains KA3 and KA4 from heavy oily sludge (HOS), their emulsification index (E24), bacterial adhesion to hydrocarbon (BATH), and oil degradation efficiency were evaluated in the MBM. Then, they were inoculated twice into the composting bioreactors lasted for the primary 8 weeks as the first phase (FP) and subsequent 8 weeks as the second phase (SP). The results indicated that the consortium of the two strains degraded 16-61% of crude oil (1-5% concentration) in the MBM. In the composting reactors, removals of 20 g kg−1 initial concentration of total petroleum hydrocarbons (TPH) were found to be 63.95, 61.00, and 89.35% for the strains KA3, KA4, and their consortium, respectively. The computed biodegradation constants indicated the synergistic effect of the two strains and the effectiveness of the second-step inoculation. The study demonstrated the successful scaling-up of HOS biodegradation from MBM to the two-phase composting process through two-step inoculation of the isolated strains

Projection of Environmental Pollutant Emissions From Different Final Waste Disposal Methods Based on Life Cycle Assessment Studies in Qazvin City

In the current study, the life cycle assessment (LCA) method was used to expect the emissions of different environmental pollutants through qualitative and quantitative analyses of solid wastes of Qazvin city in different final disposal methods. Therefore, four scenarios with the following properties considering physical analysis of Qazvin’s solid wastes, the current status of solid waste management in Iran, as well as the future of solid waste management of Qazvin were described. In order to detect the quantity of the solid wastes, the volume-weighted analysis was used and random sampling method was used for physical analysis. Of course, regarding the method of LCA, it contains all stages from solid wastes generation to its disposal. However, since the main aim of this study was final disposal stage, the emissions of pollutants of these stages were ignored. Next, considering the mixture of the solid waste, the amount of pollution stemming from each of final disposal methods from other cities having similar conditions was estimated. The findings of the study showed that weight combination of Qazvin solid wastes is entirely similar to that of other cities. Thus, the results of this study can be applied by decision makers around the country. In scenarios 1 and 2, emission of leachate containing high amounts of COD and BOD is high and also the highest content of nitrate, which can contaminate water and soil resulting in high costs for their management. In scenarios 3 and 4, the amounts of gaseous pollutants, particularly CO2, as well as nitrogen oxides are very high. In conclusion, the LCA methods can effectively contribute to the management of municipal solid wastes (MSW) to control environmental pollutants with least expenses

Assessing the Safety and Health Standards in Diagnostic Radiology Centers in Hamadan Province

Providing safety and health criteria is a very important part of the management of all diagnostic radiography centers. The prime aim of this study was to assess the safety and health standards of diagnostic radiology centers in Hamadan Province. This descriptive study that was performed in 22 imaging institutes, 21 hospitals, 1 faculty and 8healthcare centers (governmental and non-governmental) in Hamadan Province, Iran were selected. All of the X-ray radiography units (including the CT. Scan, panorex, mammography, simple radiography and portable X-Ray units) were evaluated in terms of physical status, radiation protection principals, health criteria and current condition according to the national performed standards of Ministry of Health and Atomic Energy Organization checklists. The findings showed that 106 x-ray units activated in 52 medical imaging centers in this city covering about 1.9 million people. Among 106 x-ray units, 49 were located in hospital wards and 57 were located in the other institutes in 9 townships. 36% of darkrooms, 68% of radiation rooms and 66% of control rooms were suitable in terms of physical status. 57% of health criteria factors had standard condition. Regarding to radiation protection term, the situation was unfavorable in comparison with physical status and health criteria, especially in the application of portable X-ray devices in the various wards of the hospitals. Radiology wards in Hamadan Province had obvious problems in the radiation protection principals; they need better management and maintenance to achieve the standards conditions in terms of safety and health

Effect of Hydrochar Modification on the Adsorption of Methylene Blue from Aqueous Solution: An Experimental Study Followed by Intelligent Modeling

Wheat straw, which is a carbon-rich precursor and a common agriculture waste in Sanandaj, was modified to produce hydrochar with high adsorption capacity by the hydrothermal carbonization (HTC) method. The hydrochars were tested as adsorbents to remove methylene blue (MB) from aqueous solution, and the effects of various interfering parameters, including pH, MB concentration, and adsorbent dosage, were investigated using artificial neural networks (ANNs) on adsorption modeling. Adsorption isotherms and kinetics were studied to explain the MB adsorption process. The prepared hydrochars were characterized using Brunauer–Emmett–Teller (BET), scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDAX), and high-performance liquid chromatography (HPLC) instruments. The maximum MB removal efficiency achieved by hydrochar modified by KOH (0.1 M) and adsorption data fitted well with the Langmuir isotherm and pseudo-second-order kinetics. In terms of elemental composition, the hydrochar sample contained 52.19% carbon (C), 3.37% hydrogen (H), 0.1% nitrogen (N), 0.15% sulfur (S), and 35.66% oxygen (O). The ash content in the sample was 8.50%. The recorded hydrogen-to-carbon ratio (H/C) and oxygen-to-carbon ratio (O/C) indicated a shift towards humification, implying the influence of KOH addition during the hydrochar production process. Additionally, the specific surface area of the hydrochar, as measured by the BET method, was found to be 11.54 m²/g. Among the aromatics, a significant presence of hydroxymethylfurfural (HMF) was detected, with a concentration of 4.70 g/kg DM. The modeling results demonstrated that the concentration of MB had the most substantial impact on the predicted removal, followed by pH, adsorbent dosage, and contact time

Application of UV/TiO2 Advanced Oxidation in Treating Oily Compost Leachate Generated During Oily Sludge Composting

In this work, oily compost leachate (OCL) generated during oily sludge composting was treated by UV/TiO2. OCL subsamples, gathered bi-weekly from the composting process, were thoroughly mixed and then filtered to reduce the solution turbidity. The effects of initial chemical oxygen demand (COD) concentration, UV type (A and C), pH (3, 7, and 11), reaction time (30, 60, 90, and 120 min), and TiO2 concentration (0.5, 1, and 2 g L-1) on the total petroleum hydrocarbons (TPH) and COD removal from OLC were examined. The results showed that the efficiency of the process improved with the increase in TiO2 concentration and reaction time and the decrease in pH and pollutant concentration. In the optimal conditions (UV-C, TiO2 concentration of 1 mg L-1, reaction time of 90 min, and pH of 3), 52.29% of TPH was removed. Moreover, 36.69 and 48.3% of TPH was reduced by UV-A/TiO2 and UV-C/TiO2, respectively in real conditions of OCL (pH = 6.3, COD = 1501. 24 mg L-1, and TPH = 170.12 mg L-1) during the 90 min reaction time. The study verified that UV/TiO2 has the potential to be applied to treat OCL

Synthesis of Manganese Tetroxide Nanoparticles Using Precipitation and Study of Its Structure and Optical Characteristics

Considering extensive applications of manganese tetroxide nanoparticles in various industries due to its special properties, conducting studies on how to achieve more suitable ways to produce smaller nanoparticles is of great importance. In this study, nanoparticles of manganese tetroxide (Mn3O4) were synthesized by a co-precipitation method. In order to determine the characteristics of the structure, size, and specific surface of the resulting nanoparticles, techniques such as XRD, BET, BJH, FESEM, and FTIR were employed. Also, the nanoparticles were quantified with EDS and their colony size was examined using DLS experiments. The findings revealed a production of crystalline manganese tetroxide nanoparticles with a space group of 141/amd (S.G.) (141) and a molecular weight of 228.81 with the international code of ICSD Card # 89 - 4837. The specific surface area was 32.147 m2/g with a pore volume of 0.1041 cm3/g. The XRD and EDX analyses verify the production of the Mn3O4 nanoparticles. The size of the nanostructures is approximately 19 nm. The method used in this study could produce the Mn3O4 nanoparticles in a much easier way without the need for surfactants. Compared to the nanoparticles produced in other studies, the size of the nanoparticles produced in the present study is remarkably smaller. Moreover, less amount of the metal salt was used

Prevalence and Removal Efficiency of Enterococcal Species and Vancomycin-resistant Enterococci of a Hospital Wastewater Treatment Plant

Simultaneous presence of various antibiotics and bacteria in hospital wastewaters creates a suitable environment, in which the bacteria, such as ‎enterococci become resistant to the antibiotics. The aim of this study was to evaluate the performance of different units of the hospital wastewater treatment plant (HWTP) to remove Enterococcus spp and Vancomycin-resistant Enterococcus (VRE). The study was performed on the 27 samples collected from HWTP in Hamedan, Iran during December 2014 to August 2015. Enterococcus spp and VRE were identified by biochemical tests and then the isolates were confirmed by PCR. Finally, the antibiotic susceptibility test was performed using disk diffusion methods. Of the 27 samples examined, 315 a total of enterococcal isolates were obtained. Of the 315 isolates of enterococci investigated, 162 (51.42%) were identified as E. faecium, 87 (27.61%) as E. hirae, 35 (11.11%) as E. faecalis, 11 (3.5%) as E. gallinarum, 7 (2.22%) as E. casseliflavus, 4 (1.26%) E. avium, and 9 (2.85%) isolates VR E. faecium.The results of antibiotic susceptibility testing showed that of the total 315 isolates, 146 (46.34%) were resistance to tetracycline, 9 (2.85%) were resistance to vancomycin and Teicoplanin. Lower antibiotic resistance was seen with Nitrofurantoin 2 (1.26%). This study indicates a high prevalence of multidrug resistance among E. faecium isolated from HWTP, thus, it could be considered as a threat to the health and safety of ‎wastewater workers and even public health