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Investigation of Effect of Influent Concentration and Flow Rate on Nickel Biosorption using Protonated Cystoseira indica Brown Alga in a Packed Bed Column and Modeling the Experimental Data
Ali Reza Keshtkar, Hossein Dastebashi, Morteza Ghasemi Torkabad , Mohammad Ali Moosavian,
Volume 6, Issue 4 (3-2014)
Abstract
Background and Objectives: Biosorption is a new and inexpensive technique in heavy metals removal and recovery from aqueous solutions. In order to evaluate the potential of this method for the removal of nickel ions, biosorption of nickel ions from aqueous solution was studied using Cystoseira indica biomass in a packed bed column. Materials and Methods: The uptake capacity of nickel ions was investigated using protonated biomass at different influent concentrations and flow rates. In addition, the experimental breakthrough curve obtained under definite experimental conditions was modeled using Thomas, Yoon & Nelson, Dose-Response, and Belter models. Results: It was found that increasing influent concentration from 58 to 100 mg/l led to the increase of driving force for mass transfer and uptake capacity raised from 55.84 to 95.69 mg/g. The investigation of flow rate effect showed when the process is intraparticle mass transfer controlled, a slower flow rate favors the sorption. In the case of external mass transfer control, a higher flow rate decreases the film resistance and leads to an increase in mass transfer. Modeling the experimental data revealed that the abovementioned models were suitable to predict the breakthrough curves, especially Dose-Response. Measurement of pH of the effluent solution indicated that ion exchange is one of the main mechanisms of nickel biosorption using this biosorbent. Conclusion: The results of this study are complementary of the batch equilibrium sorption experiments. Therefore, from process viewpoint, this biomass can be proposed in the sorption columns as a sorbent for nickel ions.
Use of Chlorella vulgaris microalgae in the treatment of dairy wastewater
M Khalaji, Sa Hiseini, R Ghorbani, N Agh, H Rezayi,
Volume 12, Issue 2 (9-2019)
Abstract 
Background and Objective: Nutrient-rich effluents (mainly nitrogen and phosphorus) may lead to algae blooms and many harmful effects in aquatic environments. Micro-algae have been more effective among the various methods used for the removing of nutrients from wastewater. Microalgae Chlorella vulgaris has specific characteristics such as rapid growth, resistant to systems manipulation, simple and inexpensive production technology, as well as the rapid uptake of nutrients such as phosphate and nitrate.
Materials and Methods: In the present study, two concentrations of chlorella vulgaris microalgae (13 and 26 million cells/mL) were injected into dairy effluent, diluted using distilled water by 25, 50 and 75%, and the amount of nutrient removal and microalgae growth were examined during the growth period.
Results: Results indicated that different concentrations of algae at various percentages of dilution (25, 50, 75%) had a significant effect on the removal of nutrients and algal growth (p<0.05). The absorption of nutrients (nitrate, phosphate and ammonia) were 57.01, 51.84 and 43.15 percent respectively that containing lower density of initial algae compared to the treatments of 2nd group (29.15, 51.84 and 43.15 percent) with higher algae concentration. In both algal concentrations, the highest percentage of phosphate and ammonia adsorption were in dilution of 25% effluent and the highest percentage of nitrate adsorption were in the first group with 50% dilution and in the second group with 75% dilution.
Conclusion: The more percentage of nutrients (nitrate, phosphate, ammonia) was eliminated compared to the second group (26 million cells / mL) when the microalgae concentration (group I) was 13 million cells / mL. Absorption of nutrients was decreased by increasing the concentration of microalgae. Regarding to the percentage of nitrate adsorption, the higher absorbance in the dilution was occurred at the highest concentration of algae.





				

				

				



				

				

				Algal treatment of a mixture of urban wastewater and Vinasse using Spirulina platensis microalgae
				

				

					 M Gholizadeh,  M Nosrati, 
Volume 12, Issue 3 (12-2019)
				





    Abstract




				

					
Background and Objective: Algal wastewater treatment is a new and economic technology to remove and recycle nutrients from wastewater. In order to investigate the effect of vinasse on microalgae growth and also the effect of its growth on nitrogen and phosphate removal in a mixture of urban wastewater and vinasse, the growth of Spirulina platensis was studied.

Materials and Methods: Growth ability of spirulina in the urban wastewater and the effect of vinasse on growth rate was investigated by the calculation of biomass. The effect of concentration of vinasse, intensity of light and light-dark cycle on growth rate were studied by DESIGN EXPERT and CCD method. By selecting the optimized conditions, rates of nitrogen, phosphate and COD removal was investigated at the end of the growth period.

Results: The results showed that adding vinasse to wastewater increased the growth rate and the highest amount of biomass of 3.19 mg/mL was obtained in the sedimentary stream containing 0.25% vinasse. By evaluating the effect of vinasse concentration, intensity of light and light-dark cycle on growth rate, optimal conditions at vinasse concentration 0.4% (v/v), light intensity of 5000 lux and light period of 10 hours, 480 (mg/L) of biomass was obtained. The percentage of removal of nitrogen, phosphate and COD was 63%, 97% and 73% respectively.

Conclusion: The results of this study indicated the capability of urban wastewater and vinasse in order to replace Zarouk's culture medium for growth of Spirulina microalgae. These microalgae were able to remove high percentage of nutrients in the wastewater.

 


				

				

				



				

				

				Bioremediation of selected polycyclic aromatic hydrocarbons by Chlamydomonas reinhardtii algae in synthetic crude oil wastewater
				

				

					 Navid  Ahmadi,  Mozhgan Ahmadi Nodushan,  Mohammad Hadi Abolhasani,  Seyed Abbas  Hosseini, 
Volume 15, Issue 2 (8-2022)
				





    Abstract




				

					
Background and Objective: The presence of PAHs in the environment can cause a problem as their presence has a deleterious effect on humans and animals. They also have the ability to cause tumors in humans and animals. Generally, to remove crude oil pollutants from seawater, various physicochemical and biological treatment methods have been applied worldwide. A biological treatment method using bacteria, fungi, and algae has recently gained a lot of attention due to its efficiency and lower cost. Chlamydomonas reinhardtii, microalgae have features such as a high proliferation rate, and cultivability in various water ecosystems. 

Materials and Methods: In the present study, a total of 12 samples of synthetic oil wastewater were prepared at 2.5 g/L, 7.5 g/L, and 12.5 g/L that were called C1, C2 and C3.The gas chromatography/mass spectrometry (GC–MS) method was used for the determination of PAHs compounds in the samples. Furthermore, water samples were further analyzed for the amounts of biological oxygen demand (BOD), Chemical oxygen demand (COD), and total organic carbon (TOC). Chlorophyll A, biomass, amounts of nitrate, and nitrite ​​were also measured. Statistical analysis was performed using SAS 9/8 software.

Results: Results indicated that the removal rates from crude oil by C.reinhardtii microalgae were 100% on the 14th day for the three compounds of phenanthrene, fluorine, and anthracene at all concentrations, and 97.8%, 93%, and 92.7% for naphthalene compound at concentrations of 2.5 g in 1L, 7.5 g in 1L, and 12.5 g in 1 L, respectively (p<0.05). In terms of nutrients (NO-2 and NO-3), the highest amount of nitrate removal was observed at a concentration of 2.5 g/L from crude oil (C1) (p<0.05). The highest biomass was observed in the C3 treatment (p<0.05). Moreover, the greatest decline in BOD was observed in treatment C3 at 47.4%, while the greatest COD and TOC decline were observed in C1 treatment with the value of 84% and 94%, respectively (p<0.01). 

Conclusion: The results showed that the cultivation of C.reinhardtii in crude oil in terms of nutrient removal potential, hydrocarbon composition, improving water quality and production of suitable biomass can be an acceptable option for exploitation in the biological treatment process.



 


				

				

				







			

			

				

				  
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