Research Paper
Parviz Mohammadi; Shaliza Ibrahim; Mohamad Suffian Mohamad Annuar
Volume 2, Issue 1 , March 2015, Pages 98-102
Abstract
The hydraulic characteristic of an up-flow anaerobic sludge blanket fixed film (UASB-FF) were studied by changing two important hydraulic factors that can impact significantly on the hydraulic regime of the UASB-FF bioreactor: the Up-flow velocity (Vup) and biogas production rate (Qg). The analysis of ...
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The hydraulic characteristic of an up-flow anaerobic sludge blanket fixed film (UASB-FF) were studied by changing two important hydraulic factors that can impact significantly on the hydraulic regime of the UASB-FF bioreactor: the Up-flow velocity (Vup) and biogas production rate (Qg). The analysis of the reactor hydraulic performance was performed by studying hydraulic residence time distributions (RTD) obtained from tracer (Rhodamine B) experiments. The region of exploration for the process was taken as the area enclosed by Vup (0.5 and 3.0 m/h) and Qg (14.87 and 7.96 l/d). Three dependent parameters viz. deviation from ideal retention time ( , dead volume percentage and Morrill dispersion index (MDI) were computed as response. The maximum and dead volume percentage were 33.58 min and 26 % at Vup of 0.5 m/h and Qg of 14.87 l/d, respectively. While, the minimum responses (4.15 min and 19.3 %) were obtained at Vup of 3.0 m/h and Qg of 7.96 l/d, respectively. The values of MDI computed at the minimum and maximum Vup and Qg are identified as 11.33 and 10, respectively, showing that the hydraulic regime in UASB-FF bioreactor is a semi-complete mixing.
Research Paper
Masoud Hatami; Habibollah Younesi; Nader Bahramifar
Volume 2, Issue 1 , March 2015, Pages 103-107
Abstract
This work examined the simultaneous saccharification and fermentation (SSF) process for the biological conversion rice wastewater into ethanol using co-culture of Aspergillus niger (A. niger) and Saccharomyces cerevisiae (S. cerevisiae) in batch condition. In this study, The A. niger and S. cerevisiae ...
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This work examined the simultaneous saccharification and fermentation (SSF) process for the biological conversion rice wastewater into ethanol using co-culture of Aspergillus niger (A. niger) and Saccharomyces cerevisiae (S. cerevisiae) in batch condition. In this study, The A. niger and S. cerevisiae were used for hydrolysis and production of ethanol from rice wastewater, respectively. The Effects of fermentation parameters such as pH (4, 4.5, 5 and 5.5), temperature (25, 30, 35 and 40 °C), incubation period (12 to 72 h), incubation time (12 to 72 h) and nitrogen source on SSF were evaluated. The results showed that among the optimal parameters of pH 5, temperature 35 oC, incubation period 36 h, incubation time 36 h and nitrogen source of (NH4)2SO4 were obtained in ethanol production by SSF process. Under these optimized conditions, maximum ethanol production and product yield were 16.97 g/l and 0.36 g/g, respectively.
Research Paper
Nader Bahramifar; Maryam Tavasolli; Habibollah Younesi
Volume 2, Issue 1 , March 2015, Pages 108-114
Abstract
Biosorption of two anionic dyes, eosin Y and eosin B, from aqueous solution using Saccharomyces cerevisiae was investigated in a batch mode. The influence process parameters such as contact time, initial dye concentration, sorbent dosage, pH and temperature of aqueous solution were studied. The maximum ...
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Biosorption of two anionic dyes, eosin Y and eosin B, from aqueous solution using Saccharomyces cerevisiae was investigated in a batch mode. The influence process parameters such as contact time, initial dye concentration, sorbent dosage, pH and temperature of aqueous solution were studied. The maximum adsorption capacities were found to be at 200 and 100 mg g-1 for eosin Y and 1 eosin B, respectively. The Langmuir and Temkin model were found to be appropriate for the description of biosorption process of eosin Y and eosin B, respectively. The pseudo-second order kinetic model fitted well in correlation to the experimental results for both dyes. Thermodynamic parameters such as enthalpy change (ΔH°), entropy change (ΔS°) and free energy change (ΔG°) were also investigated. Thermodynamic studies indicated that biosorption of both dyes onto S. cerevisiae was an endothermic process. The negative values of free energy change showed that the biosorption of both dyes was spontaneous at the temperatures under investigation. These results indicate that biomass S. cerevisiae particles with clean surface and high porosity are an interesting alternative for dye removal from the wastewater effluents.
Research Paper
Lee Fergusson
Volume 2, Issue 1 , March 2015, Pages 115-121
Abstract
Stormwater represents one of the least researched forms of wastewater in environmental science. Contaminated industrial stormwater, that is stormwater generated by runoff from industrial sites such as refineries, smelters and mine sites, is even less well understood. However, contaminated industrial ...
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Stormwater represents one of the least researched forms of wastewater in environmental science. Contaminated industrial stormwater, that is stormwater generated by runoff from industrial sites such as refineries, smelters and mine sites, is even less well understood. However, contaminated industrial stormwater can have damaging environmental impacts because it generally occurs in sudden bursts of high velocity and can result in significant downstream contamination. Flows of hundreds of thousands of litres of industrial stormwater are not uncommon in heavy rain events, and even when reduced through dilution, infiltration, co-mingling and by subsequent rain events, contaminants in stormwater can pose a risk to healthy urban and industrial environments. For these reasons, more research on contaminated industrial stormwater is desirable. This study considered two laboratory-scale experiments and an on-site field trial to assess three novel approaches to the treatment of heavy-metal contaminated stormwater at a smelter site in London. The approaches included the direct addition of a reagent derived from alumina refinery residue (ARR) and two filtration applications through laboratory and on-site reactive systems, both of which contained a form of pelletised media manufactured from alumina refinery residue. These three approaches resulted in the removal of inorganic contaminants from industrial stormwater, including cadmium from 0.08 mg/L to 0.0008 mg/L and copper from 0.7 mg/L to 0.0 mg/L by direct addition and arsenic from 0.34 mg/L to below the detection limit and antimony from 9.3 mg/L to 0.3 mg/L by filtration, with all post-treatment concentrations below the allowable limits for discharge. Although preliminary in nature, this study confirms other findings associated with the reuse of modified alumina refinery residue as a viable chemical raw material in industrial wastewater and solids treatment applications throughout the world, and the use of filtration of stormwater rather than the more common direct addition approach deserves further consideration.
Research Paper
Sajad Shahabi; Masoud Reza Hessami Kermani
Volume 2, Issue 1 , March 2015, Pages 122-130
Abstract
In this paper we present a method to perform flood frequency analysis (FFA) when the assumption of stationary is not important (or not valid). A wavelet transform model is developed to FFA. A full series is applied to FFA using two different wavelet functions, and then a combined method is investigated. ...
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In this paper we present a method to perform flood frequency analysis (FFA) when the assumption of stationary is not important (or not valid). A wavelet transform model is developed to FFA. A full series is applied to FFA using two different wavelet functions, and then a combined method is investigated. In the combined method, all discharge data which were less than the lowest value of annual maximum (AM) discharge were removed. Furthermore, energy function of wavelet was used for FFA. The data was decomposed into some details and an approximation through different wavelet functions and decomposition levels. The approximation series was employed to FFA. This was performed using discharge data from of the Polroud River in Iran. This paper analysis was performed on the daily maximum discharge data from the Tollat station in the north of Iran. Data from 1975 to 2007 was evaluated by wavelet analysis. The study shows that wavelet full series model results (density function) are too small in compared with the results of combined method and they are both lesser than traditional methods (AM and PD). In other hand the results of energy function method is closed to the combined method when they are compared with the full series data results. These wavelet models were assessed with the AM and PD methods. The concrete result of this paper is that, the basin hydrologic conditions and data's nature are very important parameters to improve FFA and to select the best method of analysis.
Research Paper
Akram Fatemi
Volume 2, Issue 1 , March 2015, Pages 131-136
Abstract
The suitability of Gharasoo River water for irrigation uses was evaluated in Kermanshah city, Iran. Long-term datasets including major cations, anions and other parameters such as electrical conductivity (EC), total dissolved solids (TDS) were analyzed. Sodium absorption ratio (SAR), magnesium ratio ...
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The suitability of Gharasoo River water for irrigation uses was evaluated in Kermanshah city, Iran. Long-term datasets including major cations, anions and other parameters such as electrical conductivity (EC), total dissolved solids (TDS) were analyzed. Sodium absorption ratio (SAR), magnesium ratio (MR), % sodium (%Na), residual sodium carbonate (RSC), permeability index (PI) and Ca2+/Mg2+ ratio were calculated to evaluate the suitability of Gharasoo River water for irrigation purposes. Piper trilinear diagram reveals that the water is the alkaline earth than alkaline type. Based on the SAR values plotted in the U.S. Salinity Laboratory Staff diagram, Gharasoo River water belongs to class medium-salinity hazard and low-sodium hazard (C2S1) which indicates that there is no limitation to use water for irrigation. According to FAO method, soil degradation risk was low in the study area and potential plant nutritional disorders will not be expected. Different indices showed the regional sodicity problems: the high risks for %Na, PI, Ca2+/Mg2+ and magnesium ratios for soil and clogging of irrigation systems only at one station.
Research Paper
Abbas Parsaei; Amir Hamzeh Haghiabi
Volume 2, Issue 1 , March 2015, Pages 137-142
Abstract
Distribution of velocity of flow in compound open channel due to interaction of floodplains and main channel is strongly non-uniform. Defining the distribution of flow velocity is an important factor in calculation of sediment transport and estimation of flow discharge. One of the correction factors ...
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Distribution of velocity of flow in compound open channel due to interaction of floodplains and main channel is strongly non-uniform. Defining the distribution of flow velocity is an important factor in calculation of sediment transport and estimation of flow discharge. One of the correction factors in calculation of flow discharge and shear stress are momentum and energy coefficients. In this study, the effect of and coefficients on Froude number and specific energy are assessed. Stage-discharge relationship in compound open channel was assessed using some empirical formula including Single-Channel Method (SCM), Divided-Channel Method (DCM), and modified divided-channel method (MDCM) and compared with together. When the discharge only flows in main channel all the empirical has a same result whereas by increasing the discharge and covering the floodplains by flow the results of them are different. The highest value of outcome of empirical formula is related to the SCM. Results indicated that considering the energy and momentum coefficients have significant effect on distribution of Froude number and specific energy.
Distribution of velocity of flow in compound open channel due to interaction of floodplains and main channel is strongly non-uniform. Defining the distribution of flow velocity is an important factor in calculation of sediment transport and estimation of flow discharge. One of the correction factors in calculation of flow discharge and shear stress are momentum
and energy
coefficients. In this study, the effect of
and
coefficients on Froude number and specific energy are assessed. Stage-discharge relationship in compound open channel was assessed using some empirical formula including Single-Channel Method (SCM), Divided-Channel Method (DCM), and modified divided-channel method (MDCM) and compared with together. When the discharge only flows in main channel all the empirical has a same result whereas by increasing the discharge and covering the floodplains by flow the results of them are different. The highest value of outcome of empirical formula is related to the SCM. Results indicated that considering the energy and momentum coefficients have significant effect on distribution of Froude number and specific energy.
