Study on Removing Ammonium Nitrogen from Wastewater Using Magnesium Hydroxide

2014 ◽  
Vol 955-959 ◽  
pp. 2550-2553 ◽  
Author(s):  
Yu Qi Wang ◽  
Qi Zhang ◽  
Luo Feng Liu ◽  
Bi Jun Luo ◽  
Dan Wu ◽  
...  

Magnesium ammonium phosphate (MAP) precipitation has been studied by using magnesium hydroxide and sodium dihydrogen phosphate as precipitators for treating simulation wastewater in which the concentration of ammonia nitrogen is 10.00g/L. The effect of reaction time, pH and precipitator ratio on ammonium nitrogen removal rate has been investigated. The obtained optimum treatment conditions of MAP precipitation for treating ammonia nitrogen wastewater are as follows: reaction time is 4 hours, pH is 8.0, the molar ratio of sodium dihydrogen phosphate and ammonia nitrogen in wastewater, i.e. n (P):n (N), is 1.2, the molar ratio of magnesium hydroxide and sodium dihydrogen phosphate, i.e. n (Mg):n (P), is 1.4. Under these conditions, the ammonium nitrogen removal rate, by using MAP precipitation for treating simulation ammonia nitrogen wastewater, is 90.71%.

2014 ◽  
Vol 955-959 ◽  
pp. 1907-1910
Author(s):  
Su Chen ◽  
Lei Chao ◽  
Ning Chen ◽  
Lin Shan Wang ◽  
Xue Shao ◽  
...  

When the reactor is added with ectoine of concentrations of 0, 0.1, 1 and 10 mmol/L, the impacts on brine waste treatment efficiency are investigated. The results show that the outflow COD and ammonia nitrogen removal rates are the highest, when the ectoine concentration is 0.1 mmol/L. The brine waste treatment efficiency under addition of ectoine of 1 and 10 mmol/L is even worse than that without ectoine addition. It can be preliminarily determined that the best ectoine dosage is in between 0.1-1.0 mmol/L. When ectoine concentrations added in reactors are 0.2, 0.5, 0.8 and 1.0 mmol/L, the results show that the average reactor outflow COD and ammonia nitrogen removal rates are increased compared with those of reactor without adding ectoine. But when ectoine of 1.0 mmol/L is added, the outflow COD and ammonia nitrogen removal rates decrease. When ectoine dosage is 0.5 mmol/L, the reactor outflow COD and ammonia nitrogen values are the lowest, the removal rates are the highest, the average COD removal rate is 74.46%, and the average ammonium nitrogen removal rate is 54.97%. Compared with reactor without adding ectoine, COD and ammonium nitrogen removal rates are increased by 13.16% and 26.81%. Therefore, the best dosage of ectoine is 0.5 mmol/L.


2021 ◽  
Vol 6 (2) ◽  
pp. 192-197
Author(s):  
Pepi Helza Yanti ◽  
Resti Resmalina

This paper reports the synthesis of hydroxyapatite from Geloina coaxans shell and sodium dihydrogen phosphate as precursors by facile and simple method. Firstly, Geloina coaxans shell calcined at 1000 oC for 12 hours to produce lime or CaO. The chemical composition of Geloina coaxans shell calcined was analyzed using the XRF technique, and the result shows that the main component of Geloina coaxans shell calcined was calcium. Synthesis of hydroxyapatite has been done with stirring and aging time parameters and molar ratio of precursors was 1.67.  The XRD patterns showed a specific peak of hydroxyapatite that appeared at 2θ=31.8 o and based on the XRD results on the aging time indicated that the rate of growth of HAp crystals was better and faster at aging for 12 hours. The crystal size of HAp obtained was 37 nm. The FTIR spectra of hydroxyapatite showed characteristics of hydroxyl and phosphate bands in sample spectra. The morphology of hydroxyapatite synthesized also was examined by SEM and the results showed spherical morphology.


2012 ◽  
Vol 496 ◽  
pp. 42-45 ◽  
Author(s):  
Hao Wang ◽  
Guan Wen Cheng ◽  
Xiao Wei Song ◽  
Zai Han Xu ◽  
Jin Jie Meng ◽  
...  

Ammonia is one of the most important contaminants affecting the quality of water environment. Magnesium ammonium phosphate (MgNH4PO4·6H2O), which is a slow releasing fertilizer, is one possible way to remove high strength ammonia from the wastewater. The wastewater is collected from the effluent of extraction of rare earth elements factory, the study investigate the influence of pH, magnesium and phosphate dosing molar ratio and reaction time for ammonia removal rate. The results show that: when the pH = 9.2, n (Mg): n (N): n (P) = 2.2:1:2, reaction time t = 20min, ammonia concentration of the wastewater from 4420mg / L down to 1440mg / L , ammonia nitrogen removal rate can reach 67%, the remaining TP = 0.9mg / L; higher Ca2 + concentration will affect the MAP precipitation for removing ammonia, but it help to reduce total phosphorus concentrations of effluent; it is not the longer reaction time the better removal rate, because the MAP-formation will destroy with longer reaction time.


2014 ◽  
Vol 809-810 ◽  
pp. 477-484
Author(s):  
Zhao Qing Qi ◽  
Hong Tao Wang ◽  
Jun Liang Dang ◽  
Shi Hao Zhang ◽  
Jian Hua Ding

The capacity of 10%, 30%, and 50% ammonium dihydrogen phosphate were replaced with an equal amount of three phosphate (potassium dihydrogen phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate) respectively. Magnesium phosphate cement was made by phosphate of replaced, which strength, setting time, fluidity, hydration temperature, and the hydration products was researched. The results show that: MPC was made that replaced with the equal amount of three kind of phosphate, which has good mechanical properties. Setting time and fluidity change along with the replacment. Three kind of phosphate replace ammonium dihydrogen phosphate, which change the hydration process of MPC. When ammonium dihydrogen phosphate was replaced by an equal amount of disodium hydrogen phosphate, the temperature of hydration is only 69.4 °C. XRD showed that the diffraction peaks of composite’s magnesium phosphate cement increases.


2020 ◽  
pp. 1-14
Author(s):  
Dina El Sherbiny ◽  
Mary E. K. Wahba

Abstract A simple HPLC technique has been utilized for rapid and sensitive quantitative analysis of two mixtures of drugs that are used during pregnancy and lactation. Drugs of the first mixture are used to manage gastrointestinal tract illness that are common during early stages of pregnancy, while pharmaceutical agents of the second mixture are administered over the counter as galactagogues or to overcome postpartum depression. Mixture I includes famotidine (FMT), ranitidine (RNT), nizatidine (NZT), and pantoprazole (PNT), which were separated on a C18 column using a mobile phase composed of methanol: 0.02 M sodium dihydrogen phosphate (60:40, v/v) of pH 6.9, adopting UV detection at 240 nm at a flow rate of 1 mL/min. Mixture II on the other hand, consists of domperidone (DOM), metoclopramide (MET), and sulpiride (SUL). These drugs were eluted using the same column and flow rate as those in mixture I, using a mobile phase consisting of acetonitrile: 0.075 M sodium dihydrogen phosphate (30:70, v/v) of pH 6 adopting a detection wavelength 270 nm. Two optimization protocols were utilized to optimize the chromatographic separation conditions, namely one factor at a time (OFAT) and design of experiments (DOE) where face centered cube response surface experimental design was chosen for this investigation. Comparison of the results obtained from both protocols reveals the accordance between them. Full validation procedure under guidance of United States Pharmacopoeia (USP) was applied to the proposed methods which enabled their application to separate the drugs of both mixtures in spiked rat whole blood samples and in vivo analysis of rat heart blood.


1961 ◽  
Vol 7 (2) ◽  
pp. 156-164 ◽  
Author(s):  
Edward B Hendry

Abstract With the use of the Fiske Osmometer, the mean total osmolarity of normal human serum was found to be 289 mOsM (S.D., 4), which is equivalent to a mean freezing point of -0.537°. The isosmotic concentrations of some important biologic solutions were determined. It was also found that M/15 solutions of disodium hydrogen phosphate and of potassium dihydrogen phosphate are very hypotonic, and that 3.8% sodium citrate is hypertonic. Hemolysis of erythrocytes in isosmotic ammonium chloride solution can be considerably delayed by the addition of 3.0% glucose to the solution. Isosmotic concentrations of disodium hydrogen phosphate and sodium dihydrogen phosphate were precisely determined, as were pH levels of buffer solutions made from these two salts. The cause of the slight changes in osmolarity that occur when these two isosmotic solutions are mixed is discussed.


Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1100 ◽  
Author(s):  
Ya-Wen Wang ◽  
Hua Li ◽  
You Wu ◽  
Yun Cai ◽  
Hai-Liang Song ◽  
...  

Rural runoff with abundant nutrients has become a great threat to aquatic environment. Hence, more and more attention has been focused on nutrients removal. In this study, an improved aerobic/anaerobic/aerobic three-stage water spinach constructed wetland (O-A-O-CW) was used to improve the removal of nitrogen and phosphorus of rural runoff. The removal rate of the target pollutants in O-A-O-CW was compared with the common matrix flow wetland as well as the no-plant wetland. The results showed that the O-A-O-CW significantly increased the chemical oxygen demand, total phosphorus, ammonium-nitrogen, nitrate, and total nitrogen removal rate, and the corresponding removal rate was 55.85%, 81.70%, 76.64%, 89.78%, and 67.68%, respectively. Moreover, the best hydraulic condition of the wetland, including hydraulic retention time and hydraulic loading, was determined, which were 2 days and 0.45 m3·m−2·day−1, respectively. Furthermore, the removal mechanism of the constructed wetland was thoroughly studied, which included the adsorption of nitrogen and phosphorus by the matrix and water spinach, and the nitrification and denitrification by the bacteria. The results demonstrated that the mechanisms of nitrogen removal in the new type wetland were principally by the nitrification and denitrification process. Additionally, adsorption and precipitation by the matrix are mainly responsible for phosphorus removal. These results suggested that the new O-A-O-CW can efficiently removal nutrients and enhance the water quality of the rural runoff.


2012 ◽  
Vol 577 ◽  
pp. 115-118
Author(s):  
Wen Fu ◽  
Li Wang ◽  
Li Chen

The discharge characteristics of the potassium fluorozirconate electrolyte during plasma electrolytic oxidation process were investigated. Sodium dihydrogen phosphate was applied as additives. Ceramic films were prepared on magnesium alloy in electrolytes with different content additives under constant voltage. The effect of additives on the pH of the electrolyte and the dissolution of the substrate were investigated. It was found that the additives could influence the pH and dissolved magnesium ions effectively.


Sign in / Sign up

Export Citation Format

Share Document