scholarly journals Precipitation to remove calcium ions from stabilized human urine as a pre-treatment for reverse osmosis

2021 ◽  
Author(s):  
Caitlin Courtney ◽  
Dyllon G. Randall
Keyword(s):  
Reverse Osmosis ◽  
Calcium Ions ◽  
Human Urine ◽  
Calcium Concentration ◽  
Urea Hydrolysis ◽  
Sodium Ions ◽  
Liquid Fertilizer ◽  
Pre Treatment ◽  
Ph Range ◽  
Carbonate Salts

Abstract Concentration of Ca(OH)2 stabilized urine by reverse osmosis (RO) has the potential to cause CaCO3 scaling on the membranes. The aim of this research was to determine whether the addition of carbonate salts could be used to precipitate CaCO3 prior to RO concentration and how to accurately dose the salts. Dosing of NaHCO3 or Na2CO3 reduced the calcium concentration to <0.18 mmol L−1, whilst maintaining a pH > 11. This is the pH threshold for enzymatic urea hydrolysis in urine, but above the operating pH range of most membranes. However, the pH could be decreased by adding an acid. Measuring conductivity as a proxy for the calcium concentration was found to be an effective method to determine the dose of salt required. Simulations with other carbonate producing salts (KHCO3, Mg­CO3, and NH4HCO3) were also shown to be effective. However, NH4HCO3 ($0.53 m−3 urine) was the only other salt comparable in cost to NaHCO3 ($0.49 m−3 urine) and resulted in a final pH within the normal operating range of membranes. The addition of NH4HCO3 would add extra N to the urine rather than sodium ions when dosing NaHCO3. The choice of salt will ultimately depend on what liquid fertilizer composition is desired.

scholarly journals Drying fresh human urine in magnesium-doped alkaline substrates: Capture of free ammonia, inhibition of enzymatic urea hydrolysis & minimisation of chemical urea hydrolysis

2021 ◽  
pp. 131026
Author(s):  
Anastasija Vasiljev ◽  
Prithvi Simha ◽  
Natnael Demisse ◽  
Caroline Karlsson ◽  
Dyllon G. Randall ◽  
...  
Keyword(s):  
Human Urine ◽  
Urea Hydrolysis ◽  
Free Ammonia ◽  
Ammonia Inhibition

scholarly journals Absorption of lactulose from mammalian gastrointestinal tract

1979 ◽  
Vol 41 (1) ◽  
pp. 47-51 ◽  
Author(s):  
D. F. Evered ◽  
F. Sadoogh-Abasian
Keyword(s):  
Small Intestine ◽  
Calcium Ions ◽  
Clinical Evidence ◽  
Buccal Cavity ◽  
Rat Small Intestine ◽  
Sodium Ions ◽  
Mode Of Transport ◽  
Poor Absorption

1. The disaccharide lactulose (galactosyl-β-1,4-fructose) was poorly absorbed from rat small intestine in vitro and human mouth in vivo.2. These results confirm indirect clinical evidence of poor absorption from the intestine.3. The presence of calcium ions, or absence of sodium ions, had no effect on lactulose absorption from the buccal cavity.4. The presence of ouabain, or absence of Na+, did not decrease the absorption of lactulose from small intestine.5. It is thought that the mode of transport, in both instances, is by passive diffusion with the concentration gradient.

scholarly journals Novel pre-treatment method for seawater reverse osmosis: Fibre media filtration

Desalination ◽  
2010 ◽  
Vol 250 (2) ◽  
pp. 557-561 ◽  
Author(s):  
J.J. Lee ◽  
M.A.H. Johir ◽  
K.H. Chinu ◽  
H.K. Shon ◽  
S. Vigneswaran ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Treatment Method ◽  
Seawater Reverse Osmosis ◽  
Pre Treatment

Isolated flagellar apparatus of Chlamydomonas: characterization of forward swimming and alteration of waveform and reversal of motion by calcium ions in vitro

1978 ◽  
Vol 33 (1) ◽  
pp. 235-253 ◽  
Author(s):  
J.S. Hyams ◽  
G.G. Borisy
Keyword(s):  
Calcium Ions ◽  
Beat Frequency ◽  
Flagellar Apparatus ◽  
Adenosine Monophosphate ◽  
Adenosine Diphosphate ◽  
Living Cells ◽  
Exogenous Calcium ◽  
Ph Range ◽  
Relationship Of

The control of flagellar activity in the biflagellate green alga, Chlamydomonas reinhardtii was investigated by the in vitro reactivation of the isolated flagellar apparatus (the 2 flagella attached to their respective basal bodies plus accessory structures). The waveform and beat frequency of the isolated apparatus in the presence of 1 mM adenosine triphophate (ATP) were comparable to those recorded for living cells. Equimolar concentrations of adenosine diphosphate (ADP) could be substituted for ATP with little change in beat frequency and no apparent change in waveform, suggesting that the latter is converted to ATP by axonemal adenylate kinase. No reactivation occurred in adenosine monophosphate (AMP). But frequencies in cytidine, guanosine and uridine triphosphates (CTP, GTP and UTP) were approximately 10% that obtained in ATP. Reactivation was optimal over a broad pH range between pH 6.4 and pH 8.9 in both APT and ADP. Isolated flagellar apparatus could be induced to change from forward to reverse motion in vitro by manipulation of exogenous calcium ions. The 2 types of motion were directly comparable to recorded responses of living cells. Forward swimming occurred at levels of calcium below 10(−6)M, the isolated apparatus changing to backward motion above this level. Motility was inhibited at concentrations above 10(−3)M. The threshold for reversal of motion by calcium was lowered to 10(−7)M when the flagellar membranes were solubilized with detergent, indicating that the flagellar membranes are involved in the regulaion of the level of calcium within the axoneme. The reversal of motion by calcium was itself freely reversible. The relationship of these observations to the known tactic responses of Chlamydomonas is discussed.

scholarly journals Biochemical and Molecular Studies on the Role of Rosemary (Rosmarinus officinalis) Extract in Reducing Liver and Kidney Toxicity Due to Etoposide in Male Rats

2019 ◽  
pp. 1-11
Author(s):  
Majd Almakhatreh ◽  
Ezar Hafez ◽  
Ehab Tousson ◽  
Ahmed Masoud
Keyword(s):  
Dna Damage ◽  
Calcium Ions ◽  
Chloride Ions ◽  
Male Rats ◽  
Control Group ◽  
Potassium Ions ◽  
Sodium Ions ◽  
Total Proteins ◽  
Kidney Toxicity ◽  
Liver And Kidney

Aims: Etoposide (Vepesid) is chemotherapeutic drugs that inhibit topoisomerase II activity and long been used for treatment of human malignancies, where it is a semi-synthetic compound derived from the plant Podophyllum peltatum. The current study was designed to investigate the possible protective effect of rosemary extract against Etoposide -induced changes in liver and kidney functions, and DNA damage in rats. Materials and Methods: A total of 50 male Wistar albino rats were divided randomly into four groups (1st group was control; 2nd group was treated with rosemary, 3rd group was received etoposide, and 4th & 5th groups was co- and post treated groups respectively). Results: The administration of Etoposide revealed a significant increase in serum ALT, AST, ALP, creatinine, urea, potassium ions, chloride ions, and DNA damage. In contrast; a significant decrease in albumen, total proteins, sodium ions, and calcium ions were when compared with control group. This increased in ALT, AST, ALP, creatinine, urea, potassium ions, chloride ions, and DNA damage was reduced after administration of rosemary when co-treated with etoposide (G4), or post-treated after etoposide  (G5) for four weeks with lowest damage in G4. Also, this decreased in albumen, total proteins, sodium ions, and calcium ions was increased after administration of rosemary when co-treated with etoposide (G4), or post-treated after etoposide (G5) for four weeks with lowest damage in G4. Conclusion: It could be concluded that rosemary has a promising role and it worth to be considered as a natural substance for protective the liver and kidney toxicity induced by etoposide (Vepesid) chemotherapy.

scholarly journals Effect of oxidation with coagulation and ceramic microfiltration pre-treatment on reverse osmosis for desalination of recycled wastewater

Desalination ◽  
2018 ◽  
Vol 431 ◽  
pp. 106-118 ◽  
Author(s):  
D.T. Myat ◽  
F. Roddick ◽  
P. Puspita ◽  
L. Skillman ◽  
J. Charrois ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Pre Treatment

Reverse Osmosis Membrane Desalination Technology and Process

2020 ◽  
pp. 339-372
Author(s):  
Man Djun Lee ◽  
Pui San Lee
Keyword(s):  
Reverse Osmosis ◽  
Fresh Water ◽  
Post Treatment ◽  
Polluted Water ◽  
Small Scale ◽  
Piping System ◽  
Reverse Osmosis Membrane ◽  
Pre Treatment ◽  
Desalination Technology

This chapter gives an overview about reverse osmosis membrane desalination technology and process. Desalination process can be considered as one of the crucial processes in obtaining fresh water to meet the increasing fresh water demand throughout the world. Desalination process begins with the intake of seawater or brackish water. The intake system usually comprises a pump and piping system. Then, the seawater goes through pre-treatment process. From there, the treated seawater will go through desalination process. The most widely used desalination is membrane desalination utilizing reverse osmosis membrane. After desalination process, the fresh water will go through more filtration and a series of post-treatment. Post-treatment consists of conditioning and stabilizing the water for distribution. This chapter concludes with a case study to illustrate the operation and sustainability of a small-scale desalination plant that utilizes brackish city polluted water as source.

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