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Showing 6 results for Nutrient
Comparison of Nutrients and Salinity on Phenanthrene Removal from Polluted Soil 
Maasoumeh Ravanipour, Roshanak Rezaei Kalantary, Mahdi Farzadkia, Samireh Hashemi-Najafabadi, Ali Esrafily,
Volume 5, Issue 4 (2-2013)
Abstract
MicrosoftInternetExplorer4 Background and Objectives:The poor accessibility of microorganisms to PAHs in soil has limited success in the process of bioremediation as an effective method for removing pollutants from soils. Different physicochemical factors are effective on the rate of biodegradation. The main objective of this study is to assess effects of nutrient and salinity on phenanthrene removal from polluted soils.
Materials and Methods:The soil having no organic and microbial pollution was first artificially polluted with phenanthrene then nutrients and salinity solution in two concentrations were added to it in order to have the proportion of 10% w:v (soil: water). After that a microbial mixture enable to degrade phenanthrene was added to the slurry and was aerated. Finally, the residual concentration of Phenanthrene in the soil was extracted by ultrasonic and was analyzed using GC. We measured the microbial populationusing MPN test. This study was conducted based on the two level full factorial design of experiment.
Results: MPN test showed that the trend of microbial growth has experienced a lag growth. The full factorial design indicated that nutrient had the maximum effect on bioremediation the rate of phenanthrene removal in the maximum nutrients - minimum salinity solution was 75.14%.
Conclusion: This study revealed that the more nutrient concentration increases, the more degradation will be happened by microorganisms in the soils. However, salinity in the concentration used had no effect on inhabitation or promoting on the Phenanthrene removal.


Investigating the Trend of Changes of Organic Carbon, Nitrogen, Phosphorus, and Temperature During Oily Sludge Composting Process
A Koolivand, K Naddafi, R Nabizadeh, A Jonidi Jafari, M Yunesian, K Yaghmaiean, S Naseri,
Volume 9, Issue 3 (12-2016)
Abstract

Background and Objective: The performance of in-vessel composting process, as one of the most effective methods of oily sludge treatment, depends on factors such as nutrients and temperature. Therefore, it is crucial to investigate the trend of changes of these factors. The aim of the present study was to investigate the trend of changes of organic carbon, nitrogen, phosphorus, and temperature during the composting of bottom sludge of crude oil storage tanks.

Materials and Methods: The sludge was mixed with the immature compost at the various ratios of sludge to compost including 1:2, 1:4, 1:6, 1:8, and 1:10 with the initial C/N/P of 100/5/1 and then was composted for a period of 10 weeks. The process of mixing and moisture adjustment of the mixtures was done 3 times a day during the composting period. Sampling and analysis were performed every week for organic carbon, nitrogen, and phosphorus and every day for temperature.

Results: The research indicated that the concentrations of organic carbon, nitrogen, and phosphorus were decreased sharply during the first weeks of the process and then they were decreased gently. At the final stage of the composting, the ratios of C/N and C/P increased from 20:1 and 100:1 to 26:1 and 166:1, respectively. In addition, the temperature of the reactors was kept in the mesophilic range during the process period.

Conclusion: The similar trend of decrease of organic carbon, nitrogen, and phosphorus in the composting reactors is an indication of decreasing the activity of the microorganisms involved in petroleum hydrocarbons degradation.  


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.

 


				

				

				



				

				

				Effect of EDTA on soil quality and growth and nutrients characteristics of the medicinal plant Marrubium cuneatum under potentially toxic elements stress
				

				

					 Sadegh Hosseinniaee,  Mohammad Jafary,  Ali Tavili,  Salman Zare, 
Volume 17, Issue 3 (12-2024)
				





    Abstract




				

					
Background and Objective: Ethylenediaminetetraacetic acid (EDTA) is known as a synthetic chelating agent used for the remediation of soils contaminated with potentially toxic elements. Marrubium cuneatum is a medicinal plant with phytoremediation capabilities. This study investigated the effect of EDTA on the morph-physiological characteristics of this species and its rhizosphere soil.

Materials and Methods: Under greenhouse conditions, M. cuneatum was grown for six months in mine-contaminated soil with different levels of EDTA (0, 1, 3, 5 mmol/kg).  Subsequently, its biomass, concentration of macro- and micronutrients, and soil biochemical properties—such as organic matter content, soil enzyme activity, and microbial biomass—were measured. Additionally, a regression model was established between EDTA concentration and shoot weight to predict the plant's growth response.

Results: A concentration of 5 mmol/kg EDTA decreased the dry weight of shoots and roots by 11% and 21.9%, respectively, compared to the control. The reduction in root macronutrient content was less pronounced with EDTA application compared to that of the shoots, with the greatest decrease observed for shoot potassium (40.70% compared to the control). The potassium-to-sodium ratio also decreased significantly. Despite improvements in some soil biochemical parameters at low EDTA levels, the 5 mmol/kg dose resulted in a 30% and 10% inhibition of urease and dehydrogenase activity, respectively. The regression relationship between EDTA concentration and shoot weight indicated that the maximum dry weight was obtained at a concentration of 2.4 mmol/kg.

Conclusion: Considering the adverse effects of EDTA at concentrations of 3 mmol/kg on soil and plants, as well as the predictive model of the growth response of M. cuneatum, it is suggested to investigate EDTA levels above 2.4 mmol/kg to determine the precise dose that initiates negative effects in soil and plants.

 

				

				

				







			

			

				

				  
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