Marziyeh Aghasi; Naser Mehrdadi
Volume 16, Issue 3 , October 2018, , Pages 167-180
Abstract
Introduction:
Fish processing industry produces huge amounts of solid waste and wastewater. This wastewater consists of preliminary processing of the raw fish, washing the plant, and raw offal products (e.g., blood and viscera). The high-fat content of industrial wastewater causes problems in treatment ...
Read More
Introduction:
Fish processing industry produces huge amounts of solid waste and wastewater. This wastewater consists of preliminary processing of the raw fish, washing the plant, and raw offal products (e.g., blood and viscera). The high-fat content of industrial wastewater causes problems in treatment and disposal and raises environmental crises. The purpose of this study is to select the best method for organizing a wastewater treatment in fish processing plant based on the most widely used wastewater management technologies worldwide.
Material and methods:
This research was done by the AHP method. Based on the general conditions in fish wastewater treatment plants in industrial estates and expert judgments, and by using technical, economic, environmental, and administrative criteria, the processes were carried out. Treatment of wastewater included trickling filter, aeration lagoon, anaerobic digestion, and active sludge. The obtained results were assessed by the Expert Choice software.
Results and discussion:
According to our results, the best method was the active sludge method with a score of 0.417 and after that, aeration lagoon, anaerobic digestion and trickling filter with a score of 0.284, 0.264 and 0.052, respectively, were the best choices based on the expert's opinion.
Conclusion:
According to the technical, managerial, environmental and economic criteria and sub-criteria, this study showed that the best method for wastewater treatment in a fish processing plant was the active sludge.
Naser Mehrdadi; Ali Torabian; Amir Khakpour; Mojdeh Soroush
Volume 14, Issue 2 , July 2016, , Pages 61-68
Abstract
Today, reducing waste water as one of the greatest challenges we face in the industrial process and, since the wastewater is one of the major pollutants produced in that process, the ability to restore and reuse water and to reduce water consumption represents an important step towards overall waste ...
Read More
Today, reducing waste water as one of the greatest challenges we face in the industrial process and, since the wastewater is one of the major pollutants produced in that process, the ability to restore and reuse water and to reduce water consumption represents an important step towards overall waste water reduction. This article investigates the minimization of water consumption and wastewater in the copper industry and, specifically, in Unit Three of the Khatoon Abad copper complex. One conventional method and one new method named Water Pinch are described for this purpose. In the first, second and third modes, respectively, the TSS-TDS, Turbidity-TDS and TSS-Turbidity parameters were considered as the indicators. The results showed a saving in raw water consumption of 379, 22 and 401 m3/day (equal to 25, 1.46 and 26 %), respectively, which is a significant amount.
Taher Ahmadzadeh; Naser Mehrdadi; Mojtaba Ardestani; Akbar Baghvand
Volume 14, Issue 1 , April 2016, , Pages 1-8
Abstract
Intelligent model optimization is a key factor in water treatment improvement. In current study, we applied the artificial neural networks modelling for the optimization of coagulation and flocculation processes to get sufficient water quality control over the total organic carbon parameter. ANN network ...
Read More
Intelligent model optimization is a key factor in water treatment improvement. In current study, we applied the artificial neural networks modelling for the optimization of coagulation and flocculation processes to get sufficient water quality control over the total organic carbon parameter. ANN network consisted of a multilayer feed forward structure with backpropagation learning algorithm with the output layer of ferric chloride and cationic polymer dosages. The results were simultaneously compared with the nonlinear multiple regression model. Model validation phase performed using 94 unknown samples for which the prediction result was in good agreement with the observed values. Analysis of the results showed a determination coefficient of 0.85 for cationic polymer and 0.97 for ferric chloride models. Mean absolute percentage error and root mean square errors were calculated consequently as 5.8% and 0.96 for polymer and 3.1% and 1.97 for ferric chloride models. According to the results, artificial neural networks showed to be very promising for the optimization of water treatment processes.
Akbar Baghvand,; Ali Daryabeigi Zand,; Gholamreza Nabibidhendi; Nasser Mehrdadi
Volume 8, Issue 2 , January 2011
Abstract
Column leaching tests become increasingly important for assessing the risk of release of pollutants from soil into water. In this study a column leaching test was designed to provide insight into the fate of selected PAHs in soils and their leaching behavior. Two columns (columns 1 and 2) were prepared ...
Read More
Column leaching tests become increasingly important for assessing the risk of release of pollutants from soil into water. In this study a column leaching test was designed to provide insight into the fate of selected PAHs in soils and their leaching behavior. Two columns (columns 1 and 2) were prepared based on a standard procedure in which 5 and 20 percent of contaminated soil were used, respectively. The percolates were collected at specified L/S ratios. Results showed relatively high initial concentrations of flourene, fluoranthene and benzo(a)anthracene for column 2. Released amounts of PAH compounds were decreasing with increasing molecular size, or rather the hydrophobicity of the compound. The effect of dissolved organic carbon on PAHs leaching was also investigated in this research. Approximately 2.45% and 0.67% of the total initial amounts of studied PAHs in the soil was leached in columns 1 and 2, respectively. Results showed that high PAHs concentration in the solid phase does not necessarily imply serious groundwater contamination risk during a leaching event (e.g. rain fall) and significant amount of contaminants may stay in the soil layer for a long time and do not leach down into groundwater.
Naser Mehrdadi; Gholamreza Nabi Bidhendi; Shahin Mohammadnejad
Volume 6, Issue 4 , July 2009
Abstract
In this paper, six methods of water pinch analysis are introduced to illustrate the advantages and disadvantages of each method. Although, these methods can be used in some industries which generate single contaminant during their processes, otherwise all contaminants can be considered as a single contaminant, ...
Read More
In this paper, six methods of water pinch analysis are introduced to illustrate the advantages and disadvantages of each method. Although, these methods can be used in some industries which generate single contaminant during their processes, otherwise all contaminants can be considered as a single contaminant, but actually it is impossible. On the case of multiple contaminants, we can apply pinch analysis by using mathematical programming methods. While graphical methods are unusable in the most situations, some researchers such as Wang and Smith, Gomez and James G. Mann, have developed their methods to cover the multiple contaminant problems. However, more applicable results may be achieved by using mathematical methods as discussed in relation to the Tan and Yee methods. Among the methods considered, Gomes’ mass transferring network is the most satisfactory for use in most industries. This method can be used for both single and multiple contaminant problems.
