jalal shayegan

Employing non-conventional water resources using treatment and recycling is considered as the main resource in addressing future water scarcity. Although non-conventional water recycling has been investigated in details in the literature, its impacts on irrigation-fertilizing systems have not been discussed using thermoeconomic analysis.  In this case study, using a hydroponic greenhouse system for rose cultivation, exergoeconomic cost was investigated in a recycling process by comparing three system including: open cycle, open cycle considering exergy abatement cost, and close cycle (nutrition water recycling). Results show that the exergoeconomic cost for producing 212,500 rose cut-flowers in a 6-months cold period, where heat was supplied by boiler for the above mentioned scenarios were about 15,760 $, 16,525 $ and 14,718 $, respectively. Also, the thermoeconomic indicator of the unit exercoeconomic costs for above mentioned scenarios were 74.2, 77.8 and 69.3 $Gj-1, respectively. In the close cycle, drainage water recycling decreased total exergy losses by 4.02 Gj.yr-1, of which 1.24 Gj.yr-1 reduction was due to the reduced inlet water and 1.91 Gj.yr-1 for the inlet fertilizer reduction, while that increased by the system electricity consumption was 1.12 Gj.yr-1. Water quality pyramid presented based on the unit exergoeconomic cost indicated 459.9 Gj.yr-1 for the nutrition feed  as the highest peak value and zero for the wastewater at the base of the pyramid.

Refineries are amongst the most energy-intensive and polluting industries in the world. Biotechnology may serve as an alternative low-cost and environmental-friendly tool to the current costly, toxic and hazardous refining processes. In this study, the compositional redistribution of a heavy hydrocarbon cut is investigated under biological conversion using native microbial consortia. The native consortia were obtained by batch enrichment method applied on oil-polluted soil samples from oil refineries of Iran. The bioconversion experiments were conducted with 20% and 40% (v/v) of the heavy cut as the sole carbon source and 10% (v/v) of the consortia broth in 250 ml flasks containing a mineral medium. The samples kept at 30°C stirring at 120 rpm for one week. The biotreated hydrocarbons were then separated and analyzed for determination of saturate, aromatic and resin fractions using column chromatography and gravimetric measurements. The results showed that the amounts of saturates increased by 6% to 92% while the resins decreased by 10% to 70% in most cases, compared to the blank. The GC-Mass analysis of the saturate fractions also revealed an increase in the cyclic and branched alkanes and a decrease in the S-containing and N-containing compounds.

The feasibility of measuring CO2 content in biogas was evaluated in this research. Firstly, Curtipot pH simulator was used to visualize the titration behaviors of various percentages of dissolved CO2 in a wide range of concentrations of NaOH solution. As a general output of those simulations, it was shown that when the titration curves of different CO2 content samples are separated enough, titration can provide precise information about the value of dissolved CO2. Also, when the ratio of the molar concentration of NaOH to the molar concentration of CO2 is in the range of 1 to 2(equivalent to the stoichiometric ratio of bicarbonate and carbonate), the separability of the curves is enough satisfactory to be used for precise determination of CO2; Outside this range, the accuracy of data segregation by titration diminishes. Moreover, when the ratio of the molar concentration of NaOH to CO2 is between 1 and 2, by only a one-time probing, it is possible to determine the concentration of CO2 in the standard NaOH solution. In this case, titration over a wide range of pH does not provide more reliable and accurate information. The effects of temperature CO2 measurement shows that a difference of even 10 °C can only cause less than 1% decrease in CO2 estimation. Finally, a comparison between gas chromatography and pH measurement was performed and the experimental results showed closeness the results of our proposed method with that of GC(less than 0.05% relative error). This method can be used in designing a non-expensive measuring method that would pave down the road for developing countries.

The selection of optimum high strength wastewater treatment process is complicated. Be familiar with wastewater treatment methods is not enough to design a plant. In this research, five alternative wastewater treatment methods (upflow anaerobic sludge blanket (UASB) + membrane bioreactor (MBR), UASB + Extended aeration (EA), Anaerobic baffled reactor (ABR), anaerobic lagoon (ANL) + aerated lagoon (AL), and sequencing batch reactor (SBR) + ABR) for high strength wastewater were investigated and ranked based on the analytic hierarchy process (AHP) fuzzy method. These treatment methods were investigated and ranked based on five criteria (energy consumption, effluent total suspended solid (TSS), effluent chemical oxygen demand (COD), cost, and level of technology). Rating the different options of wastewater treatment plant was done by expert decision makers in this field. The results show that for typical high strength wastewater using an UASB reactor followed by a MBR is the most appropriate alternative to treating the wastewater.

The most common method of desalination is membrane method. Despite the large application, this method has weaknesses such as limited flux and low resistance to chlorine. In this research, a solution based on the use of functional graphene oxide with thionyl chloride(GO-OCl) in a polyamide membrane structure is suggested. To implement this idea, a new method was used to optimize the production of GO-OCl membrane using Constrain Mixture Design (CMD) (a design of experiment method). For execution, according to the CMD method, thirteen combinations of three materials: trimesoyl chloride, m-phenylenediamine and GO-COCl were selected. Then the membrane properties including salt rejection, resistance to chlorine and flux were measured. With using multi-objective optimization method, the optimal concentration was obtained, and the corresponding membrane was constructed. Comparison of the optimal membrane performance with pristine membrane showed that the flux of water was increased by 50.6%, salt rejection decreased by 3%, and chlorine resistance increased by 4.91%

The aim of this present work is the synthesis of the functionalized magnetic activated carbon derived from peach stone for simultaneous removal of heavy metal ions from aqueous solutions. The various tests including XRD, BET, XRF, Boehm, VSM and FTIR were applied to characterize the prepared nano-adsorbent. The results showed the well dispersed spherical magnetite nanoparticles with size of 20 nm were formed over the nano-adsorbent while the surface area was calculated to be 325 m2/g. The Designed experimental data by employing response surface method indicated that the adsorption temperature and pH have the synergic effect on the competitive adsorption of Pb(II), Cr(VI) and Hg(II) in the liquid phase. The maximum removal efficiencies were calculated to be 91.5, 62.05 and 82.7 for Pb (II), Cr(VI) and Hg(II) at the optimal operating conditions, respectively.

The present paper briefly describes heavy metals from various aspects, the sources of production and the negative effects of these metals on human health, the standards and regulations of various agencies to comply with the permissible limits and finally, it also explores the methods of purification, separation and removal of these elements.
Regarding treatment methods, a wide range of processes and disadvantages and advantages of each of the old types to the new technologies has been investigated, including chemical precipitation, coagulation-flocculation, flotation, ion exchange, electrochemical treatment, membrane filtration and adsorption.
In this regard, absorption is considered as a simple but efficient approach, and has been specifically addressed and sorbents have been studied including active carbon, carbon nanotubes, graphene oxides and biosorbents.
Today, nanoscale materials have shown significant applications in the treatment of aquatic environments, due to their unique features such as high surface area, large active sites and high absorption capacity. In this regard, magnetic nanoparticles of iron oxides are considered as cost-effective, high-efficiency and environmentally friendly adsorbents.

Extraction and processing of oil products consume 10% of the total energy produced by fossil resource. to prevent operational problems in downstream units Oil extracted from oil fields will be sent to the desalting plant for desalination and dehydration. One of the most important steps that have a vital role in this unit is pre-heating by heaters which use natural gas produced with crude oil at the same time.   Iran is known as the area with the potential for utilization of solar systems. Investigations on  Solar thermal technologies showed that Linear Fresnel concentrator has high performance as a  solar auxiliary system for conventional heaters And leads to an annual reduction of 1.5 million cubic meters of natural gas consumption in a desalination plant. The Gas is saved can be used for feed of petrochemical plants. Investigation on the cost-benefit payback time of proposed system shows that solar Fresnel designed according to the conditions and potential of solar radiation at the site of the study is a little more than a year. Such an investment is economically justified and reduces fuel consumption and reduce carbon dioxide emissions resulting from the combustion gas. A 27% share of solar power in the supply of the thermal energy required for crude oil desalination is a step towards achieving the goals of sustainable development in the upstream oil industries.

Membrane distillation is a separation method based on heat transfer due to vapour pressure gradient between the two sides of a microporous hydrophobic membrane. Owing to advantages such as low operating temperature and pressure, and insensitivity to the concentration of influent pollutants, it is considered as an appropriate membrane-based separation process to be integrated with other separation processes and has shown good performance on the desalination of brine. In this paper, the performance of direct contact membrane distillation for desalting produced water with a salinity of 100000 mg/L has been studied by adopting heat transfer model based on the Nusselt number and mass transfer model based on the Dusty gas model. The results indicate that increasing salinity from 35000 mg/L to 10000 mg/L reduces the volume of the product by only 10%, which is retrievable through increasing the feed temperature, raising the flow rate of the feed and permeate, and reducing the temperature of permeate.
The amount of error occurred in this model in comparison with the reported experimental data was lower than 14%, and economic projections made for a unit with the capacity of 11000 barrels of produced water per day indicate that the levelized cost of producing retreated water in this method is 1.95 $/m3, which is a reasonable number for hypersaline produced water.

In this study, a lab-scale membrane bioreactor (MBR) was operated for a period of more than 10 months to determine the biokinetic coefficients of the system under the hydraulic retention times (HRT) of 20, 15 and 10 hrs and sludge retention times (SRT) of 5-20 days. The results revealed that the biological removal efficiency of styrene and ethylbenzene at a solid retention time of 20 day and a hydraulic retention time of 15 hr was higher compared to a SRT of 10 day and at the same HRT. The results also showed that the yield (Y), the endogenous decay coefficient (kd), the maximum specific growth rate (μmax), and the saturation constant (Ks) for styrene and ethylbenzene as substrate were 0.60 and 0.60 mg/mg, 0.25 and 0.25 day−1, 0.188 and 0.363 h-1, and 0.146 and 2.82 mg /l, respectively. Furthermore, ethylbenzene was more appropriate as a source of carbon to activated sludge in the membrane bioreactor than the styrene which had a lower μmax than ethylbenzene.

In this paper, a modeling tool for risk assessment analysis of the movement of hydrocarbon contaminants in the vadose zone and mass flux of contamination release into the groundwater table was developed. Also, advection-diffusion-reaction equations in combination with a three-phase equilibrium state between trapped air, soil humidity, and solid particles of unsaturated soil matrix were numerically solved to obtain a one dimensional concentration change in respect to depth of soil and total mass loading rate of hydrocarbons into the groundwater table. The developed model calibrations by means of sensitivity analysis and model validation via data from a site contaminated with BTEX were performed. Subsequently, the introduced model was applied on the collected hydrocarbon concentration data from a contaminated region of a gas refinery plant in Booshehr, Iran. Four different scenarios representing the role of different risk management policies and natural bio-degradation effects were defined to predict the future contaminant profile as well as the risk of the mass flux of contaminant components seeping into the groundwater table. The comparison between different scenarios showed that bio-degradation plays an important role in the contaminant attenuation rate; where in the scenarios including bio-degradation, the contaminant flux into the ground water table lasted for 50 years with the maximum release rate of around 20 gr per year while in the scenarios without including bio-degradation, 300 years of contaminant release into groundwater table with the maximum rate of 100 gr per year is obtained. Risk assessment analysis strongly suggests a need for bioremediation enhancement in the contaminated zones to reduce the contaminant influx to groundwater.

Over 90 percent of the wastewater treatment plants in Iran use activated sludge process. Due to increase in organic loading rates, most of these plants do not have appropriate performance. For upgrading these systems and decreasing production of the excess sludge, a UASB reactor can be used as pretreatment for decreasing the organic loading prior to the activated sludge system. Also for improving the effluent quality, a membrane can be replaced for secondary sedimentation tank, i.e. changing activated sludge to membrane bioreactor. In this study, the effect of significant changes in feed composition, due to the introduction of UASB reactor; have been investigated on the population of filamentous bacteria, COD and TS removal efficiency and membrane fouling. The results showed that the population of filamentous bacteria increased rapidly from 5 to 100 Count/µL. However, this increase does not have considerable effect on membrane fouling. With increasing MLSS concentration, the number of filamentous bacteria increased from 100 to 400Count/µL. As a result, the trans membrane pressure was raised from 1.5 to 3kpa and overall membrane resistance was increased against the effluent flux. For reducing the filamentous bacteria, a dose of 20 g Cl2 /Kg MLSS was added in few intervals for two days. It was also found the number of filamentous bacteria decreased from 400 to 100 after 5 days without decreasing the other microorganisms’ population significantly. The trans membrane pressure was also retained without any further increase.

This paper investigates the effects of factors involved in sludge anaerobic granulation. Granulated sludge formation is the main parameter contributing to the success of UASB reactors. Anaerobic granulation leads to reduced reactor size, space requirement, and investment costs. Operation costs are also greatly reduced due to lack of aeration. An important parameter affecting process performance is the size of sludge granules; the factors involved in granule size will be investigated. Some of the important parameters of anaerobic sludge granulation are: existence of growth cores as inert particles or granulated sludge, process operational conditions (Sludge Loading Rate and Organic Loading Rate, Loading rate increase and …), and environment conditions (nutrients, temperature, pH, combination and …).

This paper surveys the different theories developed on anaerobic sludge granulation. The theories are generally categorized as physical, microbial, and thermodynamic approaches. In the physical approach to the granulation process, granulation is described by such physical conditions of the reactor as upflow velocity of gas and liquid streams, suspended solids in the effluent flow, and excess sludge removal. Microbial theories are based on the properties of specific organisms and on granule properties (granule structure and its microbiology). The thermodynamic approach studies such factors as hydrophobia, electrophoretic mobility, effective energy in granule adhesion process, and effect of proton transferring activities on bacterial membrane surfaces.

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