Sharif Digital Repository

Using free laccase, enzymatic decolorization of two azo dyes were optimized. The optimum conditions with the aim of maximizing the decolorization of AB92 dye (92.30%) were: dye concentration = 11.85 mg L-1, pH = 5.1, and enzyme concentration = 98.37 mg L-1. While, these conditions to achieve the maximum decolorization yield of DR23 (95.60%) were: dye concentration = 17.68 mg L-1, pH 3.7 and enzyme concentration =97.89 mg L-1.In the second part, the laccase enzyme was covalently immobilized onto GO nanosheets. At the concentration of graphene oxide and laccase enzyme equal to 1 mg mL-1 and 0.9 mg mL-1, respectively, the enzyme loading was 156.5 mg g-1 and the immobilization efficiency was... 

To investigate the metallic cation (Ni and Pb) removal performance of the rice barn-obtained biochar which was modified by nitric acid and titanium nanoparticles (TiO2) adsorption tests were conducted in continuous and non-continuous systems. First section addressed the characterization of the synthesized sorbents using field emission scanning electron microscope (FESEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), energy dispersive X ray spectroscopy (EDX) and sorption-desorption porosity analysis (BET). In the second section, the effect of different parameters such as pH, initial concentration of the metallic ions, temperature, time, sorbent content, ionic... 

Isfahan Zirconium Production Plant (ZPP) is one of the most important plants in the nuclear industry of Islamic Republic of Iran. The wastewater of this plant contains high values of Sodium, Chloride, Nitrate and low values of Calcium, Magnesium, Zinc and Zirconium ions. Its release has been banned by international and national law because of the dangers and toxicity of its ions for the environment and living organisms. Therefore, its refinement as a compensation of Iran’s water resources in agriculture and drinking water has received a major consideration. Among the common methods to removal of these ions, membrane process method is selected due to it's major benefits such as not producing... 

Industrial wastewater treatment has always been one of the significant human being problems for the years. In particular, sewage containing heavy metals that, if discharged into nature, would have irreversible effects on the ecosystem and human health. Due to their toxic nature, heavy metals will reduce the efficiency of wastewater treatment systems if they are not efficiently treated. Also, the removal of Nitrate from the wastewater, which is one of the most stable nitrogen oxides, has always been a serious human problem in the treatment of effluents due to their high solubility in water. The simultaneous presence of nitrate and heavy metals in the effluent will cause many problems in the... 

In the presence project by using of hydrophilic polymer, Cellulose acetate (CA), we tried to modify the membrane made of Polyvinylidine fluoride (PVDF). The membranes were made by phase inversion method. In five levels, at least 10% and at most 30%, CA was added to casting solution. The hydrophilicity of membranes’ surface and pore size was increased. The permeation of the neat membrane of PVDF was less than 10 , on the other hand the permeation of the membranes, which were made by adding CA, was increased up to 500 . The increment of CA more than 20% reduced the porosity of membrane. In the next step to reduce the irreversibility fouling tried to reduce the pore size by adding some... 

In this research the performance of the Moving Bed Biofilm Rector (MBBR) in different amounts of dissolved oxygen (DO) was investigated. Reactor with a useful volume of 15 liters was used in this study. In order to obtain optimum oxygen concentration, stayed at 6, 10 and 15 hours, and at different levels of dissolved oxygen in the range 0.5 -6 mg/lit, the amount of organic material was removed respectively. Also, in two different aeration intensity of 3.5 and 5.5 liters per minute at different values of e% (percentage of filling of media) the mass transfer coefficient values were obtained. When the aeration intensity increases from 3.5 to 5.5 liters per minute, and the percentage of 40%... 

Pharmaceutical waste has attracted considerable attention, in the Past two decades. These pollutants had not previously been detected in the environment. In fact, the concentration of pharmaceuticals became a matter of concern after the increase in the production and consumption of drugs. Nowadays, considering their higher consumption and more developed detection technologies, they are found in waste water, treated water, rivers, etc. The purpose of this research is to study treatment of a Synthetic waste water contaminated by Diclofenac and Ibuprofen in a Moving Bed Biofilm Reactor. An aerobic Moving Bed Biofilm Reactor (MBBR) with the volume of 8.5 liters and Kaldness packing filling ratio... 

In this project, Olive Mill Wastes (OMW) has been considered as a raw material for a bio-refinery. The project is consisted of a design section using SuperPro Designer software and an experimental section. The biorefinery was designed using the software after conducting a survey on the production of different value added material from OMW. The designed process consisted of xanthan gum, methane gas and agriculture fertilizer production. As much as 15000 L of the diluted OMW (to 50% of the initial concentration) is purified and 88 Kg xanthan gum (in 7 days), 2840 Kg methane gas and 200 Kg fertilizer in 25 days are produced at the same time.
In the experimental section, effect of applying... 

A Microbial fuel cell is a Bioreactor in which chemical bands are broken and their energy convert to electricity by bio-catalysts such as microorganisms and enzymes.In this project, construction, substrate investigation and optimization of operational parameters were done. Microbial fuel cell as a waste water treatment method was considered in this project. As a result, different substrate were used in anode chamber of constructed microbial fuel cell. The most important ones were waste water containing ethylene glycol and crude oil.Consequently, lack of information about cathode operational parameters was led to optimum condition selection for pH, buffer concentration and ionic strength as... 

A major environmental challenge for wastewater treatment in Iran and other countries is the disposal of excess sludge produced during the biological process. This project has been developing and testing a technology that will help to overcome this challenge in Kish Island wastewater plant. Results demonstrate it can perform highly effective treatment of municipal wastewater while producing low levels of sludge.Applicationofvermifiltrationfor treatment of wastewater sludge using the Eiseniafetida earthworm species. The earthworms’ gut acted as a biofilter whereby there was reduction in the sewage wastewater’s solid and liquid organic and inorganic wastes through ingestion and expelling these... 

Microbial electrolysis cell- microbial fuel cell (MFC-MEC) coupled system is one of the novel method, for in-situ utilization from the wastewater and generating electricity and hydrogen simultaneously. In this system, required energy for microbial electrolysis cell supply by electric energy generated in microbial fuel cell. Implementation of this system is complicated, because of its unsteady state nature. In this study, it is demonstrated that the hydrogen production in such an MEC-MFC coupled sustem can be manipulated through adjusting the power input on the MEC. The power input of the MEC is regulated by adding MFCs connected into the circuit in series. When one MFC add to the coupled... 

Phenolic compounds are hazardous pollutants that are released into environment through wastewater discharges from variety of industries. Although good biodegradability has been reported at low concentrations, but at higher concentrations phenols are known to be antibacterial. In this study the Membrane Biological Reactor (MBR) with submerged hallow fiber membrane was operated at 25±2 ºC and pH=7.5±0.5 to treat a synthetic wastewater containing high phenol concentration (up to 5.9 g/l). Removal efficiency of phenol and COD were evaluated at four various “Hydraulic Retention Times” (HRT) of 24, 12, 8 and 4 hours. To test the tolerance of the bioreactor to phenol concentration various loading... 

Discharging treated or raw waste water in to surface water may cause lots of serious problems, including growth of algae, as a result of the presence of nutrients in waste water.algae decrease the concentration of dissolve oxygen in water.phosphorus removal from waste water is of absolute necessity. according to the standards set by the environmental organization, discharge the untreated waster water in to the surface water is not allowed. on the other hand, given manager facilities of deprived area,effort is channeled to reach the desired result through designing the simplest treatment systems. anaerobic-aerobic systems have remarkably been used for many years in the treatment of urban and... 

In Iran, the technical issues are not considered when changing or replacing the bed of filter. In this regard, less attention is paid for the properties of the materials (e.g. shape, aggregation, effective size and uniform coefficient of grains, etc.) used in the replaced bed of filter. Therefore, the performance of the replaced filter is not good from treated water quality, water production, and backwash interval points of view. In this project, Light Expanded Clay Aggregate, LECA, was chosen as a suitable material to be used in the bed of filter because of its favorable grain shape. The performance of LECA has been examined in both “Single- Media Filter” and “Dual-Media Filter” for... 

In this study, we investigate the effect of adding potassium persulfate (PDS) (K2S2O8) and hydrogen peroxide (H2O2) to E.coli (as a model microorganism) photocatalytic removal system in the presence of the TiO2-P25 as photocatalyst and UV irradiation. In this regard, the PDS and H2O2 oxidants were added separately in the different levels of pH and photocatalyst loading under UV irradiation. The experimental points were determined based on the central composite design (CCD) and in order to study the main and the interactive effects of the photocatalyst concentration (mg/L), oxidant concentration (mg/L) and the pH on the final concentration of E.coli (cfu/mL), a response surface model (RSM)... 

Deficiency of water leads to extensive researches on alternative water resources. recycling of wastewater for non-drinking purposes such as irrigation, industrial, green belts, forestry and streets and drainage channels washing is One of the existing methods. Therefore, sewage treatment with the purpose of reducing its electrical conductivity has been done in the current research using a real scale vermifilter. Hence, the effluent from a septic tank with a daily loading of 2 (m3/day) was pumped into the vermifilter during 45 days through a pumping system.Then, the effluent from the vermifilter by another pump entered on the surface of the substrate. The results showed that electrical... 

Antibiotic medications are widely used in medicine and veterinary medicine. Since these drugs are extremely dangerous to the environment and specially to drinking water for humans and other organisms, the need to treat these wastewater is becoming increasingly important. One of the most commonly used antibiotics is oxytetracycline which is used for a wide range of infectious diseases Husbandry wastewater is one of the wastewaters that contains high diversity and large amounts of antibiotics. In this study, the performance of a Moving bed biofilm reactor (MBBR) was investigated for removal of oxytetracycline from synthetic wastewater with similar characteristics to Husbandry wastewater. A...