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Showing 3 results for Nutrients
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.





				

				

				



				

				

				Controlling the release of high-consumption nitrogen, phosphorus and potassium fertilizers using hydrogels based on sepiolite clay nanostructure and starch
				

				

					 Maryam Fayazi, 
Volume 16, Issue 4 (3-2024)
				





    Abstract




				

					
Background and Objective: The emergence of nanotechnology and the use of nanoscale materials has made it possible to take advantage of the potential and novel applications of this technology in various fields of agriculture. Therefore, this research aims to make fertilizer for high-consumption nutrients such as nitrogen, phosphorus, and potassium (NPK) by hydrogels based on the sepiolite (Sep) clay nanostructure and starch (S).

Materials and Methods: In this study, the physical inhibition method was used to control the release of high-consumption nutrient elements of fertilizer. For this purpose, appropriate amounts of NPK salt were inserted in the structure of Sep-S hydrogels. Then, the release level of nutrients was investigated by the column elution and measuring the conductivity of the outlet solution of the column.

Results: The elution profile of the NPK fertilizer shows that the salts quickly leave the end of the column so that the conductivity of the solution at the end of the column in the first washing after consumption of 250 mL of water reaches about 12000 µS/cm. On the other hand, the elution profile of the slow-release fertilizer containing NPK salts shows that the release profile of the fertilizer in 4 times of washing with the same volume is almost similar (range 1400 µS/cm to 2300 µS/cm). Results show that the placement of fertilizer salt inside the proposed hydrogels leads to the slow release of highly consumed nutrients.

Conclusion: The release of nutrients from the structure of slow-release fertilizer based on Sep-S hydrogels has a delay, which is vital to prevent the excessive release of nutrients, and minimize negative environmental effects and excessive consumption of chemical fertilizers. Also, the materials used to make the slow-release fertilizer have a relatively low cost.

 


				

				

				



				

				

				The effect of municipal solid waste compost on the reduction of lead and zinc toxicity and uptake of nutrients by two medicinal species Marrubium cuneatum and Verbascum speciosum in a soil contaminated with heavy metals
				

				

					 Sadegh Hosseinniaee,  Mohammad Jafary,  Ali Tavili,  Salman Zare, 
Volume 16, Issue 4 (3-2024)
				





    Abstract




				

					
Background and Objective: The toxicity of heavy metals is one of the most important environmental issues in the current century. This research aimed to investigate the effect of municipal solid waste compost on the absorption of nutrients and lead and zinc metals in M. cuneatum and V. speciosum plants. 

Materials and Methods: In a greenhouse experiment, compost at four levels (0, 1, 3 and 5% w/w) was completely mixed with natural soil contaminated with heavy metals (Pb and Zn). After six months of harvesting the plants, the shoot and root biomass was determined. Also, the concentration of macronutrients and micronutrients, Pb and Zn in the roots and aerial parts of plants and available Pb and Zn in the soil were measured using the ICP-OES. In order to investigate the correlation between the measured plant and soil parameters, principal component analysis (PCA) was performed

Results: Compost significantly improved the shoot dry weight of M. cuneatum and V. speciosum by 13 and 19%, respectively. 5% compost significantly reduced shoot lead by 64 and 34.4% in M. cuneatum and V. speciosum, respectively, compared to the control. Compost was more effective in increasing potassium, phosphorus, copper, and nickel than magnesium, manganese, and calcium, and increased shoot potassium by 22 and 32%, respectively, in M. cuneatum and V. speciosum compared to the control; this increase was 30 and 14% for copper and 19 and 21% for phosphorus, respectively. PCA analysis showed that, among the investigated elements, potassium, phosphorus and copper were most affected by composting and had the maximum role in improving plant growth and reducing lead toxicity.

Conclusion: Municipal solid waste compost improved the growth of M. cuneatum and V. speciosum and reduced phytotoxicity by immobilizing lead in the soil.

 


				

				

				







			

			

				

				  
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