Resubmission Fertilizer Procedural Design PDF

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CHM 3120L Analytical Chemistry Project 1: Fertilizer Procedural Design Ta: Alice Boone

Megan Rowe, Sergio Camacho, Pablo Sendon

1 Introduction and Overview In this procedural design, Vacuum filtration methods will be used to determine the quantity of phosphorus in a given sample of fertilizer. In order to measure the amount of phosphorus it must be isolated from the other ingredients. All the ingredients contained in the fertilizer are soluble in water, as this allows the mixture of nutrients to penetrate the soil and be readily absorbed by the plant. After dissolving the sample of fertilizer in distilled water, phosphorus in the form of aqueous phosphate is reacted with magnesium sulfate and ammonium hydroxide. This forms an insoluble magnesium ammonium phosphate precipitate (Struvite). This white precipitate, which contains all phosphorus present in the original fertilizer will be filtered, dried and weighed, and compared stoichiometrically to the reactant phosphorus used. This quantitative approach will aid in the determination of the amount of phosphorus present within the original sample. After validating that MAP can be created the procedure will then be used to aid in solving a real-life experimental question.

1.1 Making MAP from a Known Source of Phosphate The synthesis of Magnesium Ammonium Phosphate (MAP) follows a crystallization experiment generally accepted within the chemical reaction below:

Mg2+ + NH4+ + HPO42- + 6H2O → MgNH4PO4× 6H2O + H+

(1)

With the use of such concentrations of soluble ions, phosphorus recovery from wastewater has shown great promise in converting such excess debris into reusable material for broader application (2). Following the experimental guidance of the provided study, the following procedures can be implemented to make MAP from sewage, a common wastewater mainly containing HPO42- and NH4+ . It is also modeled after other experiments concerned with similar purposes and methodology (1). Focus is made toward the dominant form of phosphate P as hydrogen phosphate (HPO 42) in order to minimize acidification within the products. As MAP formation is favorable in alkaline conditions, the solution would be controlled to a pH of 9.0 via introduction of 20% sodium hydroxide solution. Limiting agents of Mg2+ would be supplemented with continuous 97% doses of 3.46 mM of MgCl2. Molar ratio of MAP thus follows as 1.05:1 (Mg:P). Therefore, optimal conditions concerning pH, temperature of solution, ion presence, and molar ratio are controlled at the highest level to ensure maximum recovery and efficiency. Product recovery and purification could be achieved through a reactor consisting of peristaltic pumps that feed the magnesium source and wastewater according to measured amounts. Aeration mechanisms through units can also provide agitation and mixing within the centrifuge liquor.

1.2 Specifics of the Apparatus In order to be processed in the centrifugal plant, crude centrate liquor is treated with Sodium hydroxide to adjust the pH to 9.0 for optimal extraction. The influent is then fed into the primary settlement tank of the plant, along with seeded MgCl2. The PST is also exposed to constant aeration through a pump connected to aeration

stones. It is then processed through the bionutrient removal process, with excess activated sludge being held in an SAS tank. The centrifuge then subjects the activated sludge through thickening and digestion processes, and extracts the thickened sludge as centrifuge cake. Remaining centrifuge liquor undergoes additional processes of purification and filtration and is extracted as effluent containing P in liquid form for later crystallization. Final confirmation of crystallization uses X-ray diffractograms as centrifuge cake containing the majority of extracted P accumulates throughout the stainless steel mesh of the apparatus. The remaining liquid P contained in effluent undergoes further processing and extraction. Calculations would then follow to determine percentage of P recovery and MAP synthesis.

1.3 Calculating the Percentage of Phosphate Following the chemical equation of MAP synthesis below: Mg2+ + NH4+ + PO43- + 6H2O → MgNH4PO4×6H2O

(2)

1.4 Calculating Percent Conversion To calculate the percentage of phosphate successfully turned into Magnesium Ammonium Phosphate, stoichiometric calculations would have to be conducted to verify reactant and product conversion. As MAP is commonly a white crystalline substance, the total amount formed would be collected and weighed in grams. Then, the grams of MAP are converted to moles of MAP, which correspond to a molar ratio to PO43- . This ratio is then changed into grams of phosphate successfully turned which are divided by the total amount of phosphate reactants added at the beginning of the reaction. Mathematical simplification goes as follows: (3)

(4)

1.5 Calculating Percent Yield As a reactant within the sewage sample, PO43- has a 1:1 stoichiometric ratio with the product NH4MgPO4 being measured. Thus, the molarity of the sewage sample should determine the theoretical yield in moles of Struvite. After collecting the yield in mass of struvite crystals from the Centrifuge cake and effluent centrifuge liquor, total yield in grams of crystallized struvite can be compared to the amount grams of phosphate dissolved in the sewage sample. Then, to calculate the percent yield of struvite, the following operations can be performed:

TOTAL yield of struvite (g) x (5)

1 mol =TOTAL moles of struvite obtained 245.41 g struvite

Molarity of PO43- within Sewage sample * Volume of sewage(L)=TOTAL phosphate (moles) Percent yield=

(6)

TOTAL moles of struvite obtained x 100 TOTAL moles of phosphatereacted

(7)

1.6 Experimental Question The experimental question follows: To quantify and verify the mass percent of phosphate in SoyShot™ starter fertilizer. West Central Distribution’s SoyShot™ starter fertilizer poses a great importance to the agricultural and economic fields of the United States. As soybean crops are one of the most common and widely used products in the nation, a fertilizer made to strengthen crop safety and improve overall production should be examined to verify its suggestive effects. Furthermore, SoyShot™ holds an NPK value of 0-10-10, the brand guarantees 10% phosphorus in P2O5 form within each supply. This value is the key focus due to the critical biochemical role of phosphorus in plant growth. Additional benefits include a low salt index and the company’s Levesol, an EDDHA chelating agent that increases phosphorus availability.

2 Hypothesis SoyShot™ Fertilizer label states it has a percent composition of 10% Phosphorus, 10% Potassium, and 80% other additives. If so, then 10% phosphorus could be reacted with and precipitated separately into MgNH 4PO4and measured relative to the total amount of initial fertilizer measured.

3 Reactions P4O10 + 6H2O → 4H3PO4

(8)

MgSO4 → Mg2++ SO42-

(9)

NH4OH → NH4++ OH-

(10)

Mg2++ NH4++ OH-

(11)

Mg2+ + NH4+ + PO43- + 6H2O → MgNH4PO4×6H2O (12)

4 Materials and Glassware 4.1 Precipitate Synthesis ● ● ● ● ● ●

250 mL Flask Deionized water 5g Fertilizer Sample Magnesium Sulfate Ammonium hydroxide Stirring rod

4.2 Vacuum filtration ● ● ● ● ● ● ●

Ring stand Ring stand clamp Büchner funnel Filter paper Büchner flask ie.suction flask Rubber hose Rubber stopper

4.3 Quantitative Analysis ● ● ●

Scale 50 mL beaker (for final weighing) Spatula ie. scraper

5 Procedure 5.1 Precipitate Synthesis 1. 2. 3. 4. 5. 6.

Weigh 5.00g of sample fertilizer and record the mass Obtain a 250 mL beaker and transfer sample fertilizer Measure 100 mL of deionized water an add it to the beaker Stir frequently for three to four minutes or until fertilizer has completely dissolved Add 30 mL of 20.0% MgSO4 solution onto the fertilizer solution and stir consistently for three minutes Add 70mL of 1.0M NH4 OH and swirl the mixture in the beaker until solution appears murky and consistent chalky precipitates can be observed. Use caution while waiting and observing precipitate

5.2 Vacuum Filtration 1. 2. 3. 4. 5. 6.

Obtain materials and glasswares; assemble vacuum filtration apparatus by attaching the Büchner funnel to the filter flask with the addition of a rubber stopper (ensure there is a tight seal) Using the rubber hose, connect the Büchner funnel to the laboratory’s vacuum Place a circular filter paper inside the funnel, which should cover all the holes but not come up the sides Wet the paper with some DI water (solvent) and then turn on the vacuum Add the mixed solution completely into the Büchner funnel; with some DI water (solvent), wash out any remaining particles in the 250mL flask Record any observations and allow for the collection of impurities into the receiving beaker. Wash the collected material with cold DI water (solvent)

5.3 Qualitative Analysis 1. 2. 3. 4. 5. 6. 7.

Obtain a measurement scale and make sure it is calibrated and tared before using Obtain a 5mL beaker and measure mass on scale. Record mass Once Vacuum filtration is complete, use a spatula/scraper to transfer all precipitate to the 5mL beaker Measure mass of beaker with precipitate and record mass Cover the beaker and allow precipitation to dry Once crystals have sufficiently dried, return the beaker to the scale and record mass Subtract the final mass form the initial mass of the baker and perform calculations based on the mass of total product obtained (weight by difference technique)

References [1] Lee Kwanyong Yu Min Sung Park Ki Young Kim Daegi, Min Kyung Jin. Effects of ph, molar ratios and pre-treatment on phosphorus recovery through struvite crystallization from effluent of anaerobically digested swine wastewater. Environmental Engineering Research, 22(1):12–18, 2017.

[2] YingHao Liu, Sanjay Kumar, Jung-Hoon Kwag, and ChangSix Ra. Magnesium ammonium phosphate formation, recovery and its application as valuable resources: a review. Journal of Chemical Technology & Biotechnology, 88(2):181–189, 2013....