The Use of Artificial Neural Network (ANN) for Modeling of Ammonia Nitrogen Removal from Landfill Leachate by the Ultrasonic Process

Background: The study examined the implementation of artificial neural network (ANN) for the prediction of Ammonia nitrogen removal from landfill leachate by ultrasonic process.Methods: A three-layer backpropagation neural network was optimized to predict Ammonia nitrogen removal from landfill leachate by ultrasonic process. Considering the smallest mean square error (MSE), The configuration of the backpropagation neural network was three-layer ANN with tangent sigmoid transfer function (Tansig) at hidden layer with 14 neurons, linear transfer function (Purelin) at output layer and Levenberg–Marquardt backpropagation training algorithm (LMA).Results: ANN predicted results were very close to the experimental results with correlation coefficient (R2) of 0.993 and MSE 0.000334. The sensitivity analysis showed that all studied variables (Contact time, ultrasound frequency and power and pH) had strong effect on Ammonia nitrogen removal. In addition, pH was the most influential parameter with relative importance of 44.9%.Conclusions: The results showed that neural network modeling could effectively predict Ammonia nitrogen removal from landfill leachate by ultrasonic process

The Use of Artificial Neural Network (ANN) for Modeling of Ammonia Nitrogen Removal from Landfill Leachate by the Ultrasonic Process

Background: The study examined the implementation of artificial neural network (ANN) for the prediction of Ammonia nitrogen removal from landfill leachate by ultrasonic process.Methods: A three-layer backpropagation neural network was optimized to predict Ammonia nitrogen removal from landfill leachate by ultrasonic process. Considering the smallest mean square error (MSE), The configuration of the backpropagation neural network was three-layer ANN with tangent sigmoid transfer function (Tansig) at hidden layer with 14 neurons, linear transfer function (Purelin) at output layer and Levenberg–Marquardt backpropagation training algorithm (LMA).Results: ANN predicted results were very close to the experimental results with correlation coefficient (R2) of 0.993 and MSE 0.000334. The sensitivity analysis showed that all studied variables (Contact time, ultrasound frequency and power and pH) had strong effect on Ammonia nitrogen removal. In addition, pH was the most influential parameter with relative importance of 44.9%.Conclusions: The results showed that neural network modeling could effectively predict Ammonia nitrogen removal from landfill leachate by ultrasonic process

Survey of effective parameters (Water sources, seasonal variation and residual chlorine) on presence of thermotolerant coliforms bacteria in different drinking water resources

Thermotolerant Coliforms (TtC) bacteria is one of the microbial quality indicators of drinking water. This study was aimed to Survey of Effective parameters (Water Resources, Seasonal Variation and Residual Chlorine) on Presence of thermotolerant bacteria in drinking water. For this study, data of the last 10 years assessments of microbial quality regarding various species of fecal coliform was taken from health centers associated with urban, rural and private sources of Kermanshah city. A total number of 8643 samples were taken, 1851 samples from rural, 365 from urban and 4834 from private resources. The results showed that fecal coliform, Escherichia coli (22.3%) and Klebsiella (2%) were the most and least bacteria existent in urban water resources, respectively. In rural water sources, E. coli (45.9%) and Enterobacter cloacea (2.6%) and in private sources E. coli (34%) and Klebsiella (1.3%) had the most and least existent, respectively. Further, E. coli (47.5%) and Klebsiella (0.4%) had, respectively, the highest and lowest distribution in all months considered. In addition the results showed a significant decrease of distribution of fecal coliforms with increasing residual chlorine, while a decreasing trend is observed from the dose of 0.8 mg/L. According to the results, it can be stated that among fecal coliforms, E. coli has the widest distribution in water resources and because this bacterium causes diseases such as diarrhea and hemolytic uremic syndrome, so is of particular importance in the monitoring of water resources. Hence it is necessary to consider the bacterium in resources with low microbial quality, especially in the hot seasons

Optimization of the electrocoagulation process for sulfate removal using response surface methodology

Sulfate concentrations affected on the natural sulfur cycle in the anaerobic treatment, therefore pretreatment of wastewater containing sulfate must be considered. In this work electrocoagulation techniques have considered as an effective and environmentally friendly process for desulfurization from wastewater. Three factors including initial pH, initial sulfate concentration and current density were selected as the effective factors and were optimized using response surface methodology. An initial pH of 8, initial sulfate concentration of80mg/l and current density of12mA/cm(2)were determined to be optimum values by the statistical models. The maximum sulfate removal and minimum sludge generation under optimal conditions were 68.5% and 0.075g, respectively. The kinetics of sulfate removal study investigated the pseudo-first models were better described experimental data and was selected as overall kinetic removal of sulfate

Health-related Microbial Quality of Drinking Water in Kangavar, Western Iran

Evaluation of the microbial quality of drinking water can prevent the water-borne diseases outbreak that is one of the most important challenges in the world. Therefore, the aim of this study was to assess the seasonal variation of water-borne diseases prevalence associated with the microbial quality of drinking water and the comparison between rural and urban areas in Kangavar city, west of Iran. To accomplish this study, the results of the microbial quality of drinking water and cases of simple diarrhea, dysentery, typhoid and hepatitis A were received from all rural and urban health centers of the city during five years (2006-2010). To determine the relationship between diseases and microbial quality of water, Correlation instruction and Pearson correlation coefficient were used. The results showed that except hepatitis A, the incidence of all diseases in different areas (urban or rural) and seasons had significant relationship with microbial contamination of drinking water (P-value<0.05). The stronger relationship was observed in rural areas than in urban areas (except simple diarrhea) and in warm seasons than in cold seasons. With respect to the impact of the microbial quality of water on the incidence of dysentery and typhoid diseases, keeping up the quality of drinking water in places and times with high sensitivity (rural areas and warm seasons) should be considered strongly

Modeling Trihalomethane (THM) Formation due to River Water Chlorination

The aim of this study was to develop a model for estimation of major THMs produced as a result of river water disinfection. Experiments were designed for this purpose and different ratios of Cl2 to DOC were created in water samples to which were then added different concentrations of bromide ions. After the incubation period, analyzers were used to measure natural organic compounds, TOC, and DOC in the samples and the data thus obtained were fed into the SPSS software. Moreover, multivariate regression analysis was performed to extract the relevant statistical model. Four different formulas were obtained for predicting the rate of each of the THMs produced. Reaction time and bromide ion concentration were identified as the main factors involved in the production of THMs in the water supply investigated. In addition, the carcinogenicity of THMs in water samples reached its maximum with bromide concentrations between 207 and 246 µg/l. The formulas obtained in this study can be used as a simple and accurate tool for the initial estimation of THMs production in different water supplies

Using the IRWQIGT Index to Determine Toxicity Levels in Groundwater Resources: A Case Study of Semnan Province

The objective of the present descriptive-analytic study was to estimate the toxicity level of the groundwater resources in the Province of Semnan using the IRWQIGT index and its zoning via GIS. The experiments were conducted over the period from October 2013 to October 2014during which time monthly samples were taken from the 41 wells that supply drinking water to the cities and towns in the Province. All the samples were subjected to lab analyses at Semnan Water and Wastewater Laboratory where such chemical parameters as Arsenic, Phenol, Mercury, Detergents, Cadmium, Lead, Chromium, Cyanide, Iron, Magnesium, and TPH were determined according to the procedures of Standard Methods (2008). The measuerments were subsequently used to calculate the groundwater toxicity level index (IRWQIGT). Finally, a zoning map of the IRWQIGT index for Semnan Province was prepared using GIS. Results showed that the IRWQIGT index in Semnan Province ranged between 96.54 and 98.2, indicating an excellent water quality. The lowest (96.585) and highest (98.076) values of IRWQIGT were recorded in the cities of Sorkheh and Mahdishahr, respectively, and that the values for all the parameters were in the standard range. These results indicate that water of excellent quality is available in all the cities in the province so that no toxicity treatment is required

Removal of Reactive Black 5 dye from Aqueous Solutions by Adsorption onto Activated Carbon of Grape Seed

Background and purpose: The control of environmental pollution especially the pollution of water resources is one of the main challenges of researchers throughout the world. So, this study aimed to investigate the efficiency of reactive black 5 dye removal from aqueous solutions by adsorption onto activated carbon of grape seed. Materials and Methods: At first, the grape seed adsorbents were prepared in three forms of raw, treated by concentrated phosphoric acid, and calcined at 400, 600, and 800 &deg;C. Then, the efficiency of adsorbents to the removal of the Black 5 dye was studied in the concentrations of 100 to 700 mg/Lat pH 2- 10 and 1- 10 g/L of adsorbent during 120 min. The change of concentration was studied via the spectrophotometry procedure at the wavelength of 597 nm. Finally, the Langmuir and Freundlich adsorption isotherm was determined. Results: The results showed that the dye removal efficiency decreased by increasing pH, and increased by raising the contact time and the amount of adsorbent. So, in this process, the highest percentage of Black 5 dye removal (83.08%) was obtained at pH 2 and t 120 min using the raw adsorbent, 200 mg/L initial concentration of dye, and 10 g/L of carbon. The process considerably followed the Langmuir adsorption isotherm (R2 0.999). Conclusion: The grape seed was found to have the highest level of efficiency in dye removal, and according to the availability of adsorbent and its low price, this method could be used as an applicable procedure for the removal of Black 5 dye from aqueous solutions

Modelling of Disinfection by-products formation via UV irradiation of the water from Tajan River (source water for Sari drinking water, Iran)

Background &amp;amp; Aims of the Study Irradiation with ultraviolet light (UV) is used for the disinfection of bacterial contaminants in the production of potable water. The main objective of the study was to investigate and model Disinfection By-Products (DBPs) formation due to the UV Irradiation of the Tajan River water under different Irradiation conditions. Materials &amp;amp; Methods: &nbsp;Water samples were collected throughout September 2011 to August 2013. Transportation of the sample to the laboratory was done on ice in a cooler, and physiochemical analysis was conducted immediately within one day. Dissolved organic carbon (DOC) was determined by a TOC analyzer. Irradiation experiments were conducted in a series of 25 mL glass serum bottles with Teflon septa. The present study adopts an orthogonal design. The design involved irradiation with UV at a UV/DOC ratio of 0.5&ndash;3.0 and incubating (headspace-free storage) for 5&ndash;25 sec. A 1 mM phosphate buffer maintained the pH at 6, 7, or 8 respectively, and an incubator maintained the temperature (Temp) at 15, 20, or 25 &deg;C respectively. The development of empirical models for DBPs formation used a multivariate regression procedure (stepwise) which applied the SPSS System for Windows (Version 16.0). Results: &nbsp;The results showed that the total DBPs formation ranged between 12.3 and 67.4 mg/l and that control of the levels was primarily due to the reaction time and the dissolved organic carbon level (DOC) in the water. Conclusions: &nbsp;Reaction time and level of DOC concentrations in water exerted a dominant influence on the formation of DBPs during the UV irradiation of water from the Tajan River. The relationships between the measured and predicted values were satisfactory with R 2 values ranging from 0.89 (for Octanal)&ndash;0.92 (for Formaldehydes). The DOC level in water is the key factor in controlling DBPs formation

Pyrite nanoparticles derived from mine waste as efficient catalyst for the activation of persulfates for degradation of tetracycline

Pyrite mine waste was used as a non-toxic and natural catalyst for the activation of peroxydisulfate (PDS) and peroxymonosulfate (PMS) to oxidize tetracycline (TTC), one of the most extensively used antibiotics worldwide, in contaminated water. The results demonstrated that PMS was activated more effectively than PDS by using pyrite. Scavenging experiments indicated that both OH[rad] and SO4[rad]− were the main oxidative species in the pyrite/PMS process, while SO4[rad]− was more dominant. A high degradation of 98.3 % and significant mineralization (up to 46 %) of TTC (50 mg/L) were achieved using pyrite activated PMS at a reaction time of 30 and 60 min, respectively. In-vivo toxicity of raw and pyrite/PMS treated TTC solutions was evaluated using biochemical and histopathological assays. The results revealed that the pyrite/PMS process significantly decreased the nephrotoxicity (90 %) and hepatotoxicity (85 %) effect of TTC. Catalyst reusability was evaluated under cycling conditions. No significant decrease in process efficiency was measured between the first and fourth cycle (&lt;3% decrease in TTC removal). In conclusion, mine waste pyrite nanoparticles can be considered as a non-toxic and clean catalyst to activate PMS for an effective detoxification, degradation, and intermediate mineralization of TTC, as a refractory water pollutant.</p