Removal of Soluble Phosphates From Water

1975 ◽  
Vol 10 (1) ◽  
pp. 193-213
Author(s):  
Chia-Su Wan ◽  
Maurice Adelman

Abstract Chemical treatment using ferric chloride or aluminum sulfate in combination with calcium hydroxide has been studied for the purpose of removing phosphorus from ortho-phosphate, ortho-and pyro-phosphate and ortho- pyro- and tripoly-phosphate solutions in the pH range 7.5 to 9.5. The data showed that pyro- and tripoly-phosphate could be more easily removed than ortho-phosphate in the experimental pH range. The data also showed that the combination of ferric chloride and calcium hydroxide had better settling ability than the combination of aluminum sulfate and calcium hydroxide. With a molar ratio of 1:1 between iron or aluminum and phosphorus as ortho-phosphate and 150 mg/1 of calcium hydroxide, a supernatant of about 1 mg/1 P was obtained from a phosphorus solution of 10 mg/1 P as ortho-phosphate, 4 mg/1 P as pyro-phosphate and 6 mg/1 P as tripoly-phosphate near pH 9. After filtration through a sand column, the residual phosphorus was reduced to about 0.6 mg/1 P. The residual phosphorus could be further reduced to less than 0.2 mg/l P during the first eight hours and about 0.3 mg/1 P even after 24 hours by using a mixed column of sand and soil to replace the sand column.

2010 ◽  
Vol 45 (3) ◽  
pp. 317-326 ◽  
Author(s):  
Murat Eyvaz ◽  
Hatice Deniz ◽  
Tuğrul S. Aktaş ◽  
Ebubekir Yüksel ◽  
Ahmet M. Saatçi

Abstract Pre-ozonation–coagulant interactions effects in relation to the coagulant type and dosage in direct filtration of surface waters were investigated. The performance of the process was evaluated by monitoring the effluent quality and head loss development through the filter bed. Two identical pilot scale filter columns filtering the same raw water were operated in parallel. The raw water was brought from Ömerli Reservoir in Istanbul. Before filtering, the raw water flow was split into two equal flows. One of the streams was pre-ozonated and the other was aerated using contact chambers with equal volumes equipped with same number and type of diffusers. In coagulation experiments, one of the filters was operated using aluminum sulfate as a coagulant while the other one was run with ferric chloride. For similar filter run times, the effluent quality was always better with pre-ozonation compared to aeration. It was also observed that, aluminum sulfate application gave more favorable results for both particle and turbidity removal compared to ferric chloride. Ives’ filterability index which incorporates the important filtration design parameters such as: effluent quality, the headloss and the velocity of filtration into a dimensionless number was used for the comparison of the experimental results.


2019 ◽  
Vol 25 (6) ◽  
pp. 19-29
Author(s):  
Shams Asem Mahdi ◽  
Raghad Fareed Qasim

This research presents a study for precipitating phosphorus (as phosphate ion) from simulated wastewater (5ppm initial concentration of phosphorus) using calcium hydroxide Ca(OH)2 solution. The removal of phosphorus by Ca (OH)2 solution is expected to be very effective since the chemical reaction is of acid-base type but Ca(OH)2 forms complex compound with phosphate ions called. Hydroxyapatite Ca5 (PO4)3OH. hydroxyapatite is slightly soluble in water. This research was directed towards sustainable elements as phosphorus. Kinetics of the dissolution reaction of hydroxyapatite was investigated to find the best factors to recover phosphorus. The effect of concentration of Ca(OH)2 (180- 380 ppm) on phosphorus precipitation on the outputs like the residual phosphorus concentration in the simulated solution, the percentage removal of phosphorus and the weight of the precipitate was also studied. The residual phosphorus decreased with increasing Ca(OH)2 concentration while the percentage removal, as well as the weight of the precipitate, increased with increasing Ca(OH)2 concentration at constant temperature and mixing speed. The best Ca(OH)2 concentration was obtained depending on the lowest amount of the residual phosphorus concentration. The best value obtained was 230 ppm at a fixed mixing speed of 400 rpm and a temperature of 20°C.  The best value for Ca(OH)2 concentration under fixed stirring speed and temperature was applied on a real wastewater taken from the detergent factory. The percentage removal was 30. 69% due to the complexity of the real sample. Oxalic acid was chosen to dissolve hydroxyapatite because it is an organic acid, less hazardous than mineral acids and of less cost. Kinetics of the dissolution reaction of hydroxyapatite in (160 ppm) concentration oxalic acid under ambient conditions (20°C and 1 atm (and mild stirring (200 rpm) was studied using the differential method for determining the order of the reaction which was 0.4296 and the rate constant 0.0743 (L/mg)-0.5704. min-1. The reaction was considered as a rate-controlled reaction.  


1986 ◽  
Vol 18 (1) ◽  
pp. 43-54
Author(s):  
Raymond A. Sierka ◽  
Paul H. King

Tar sand deposits offer long-term potential for satisfying future energy needs. Two large field-scale extraction experiments near Vernal, Utah, employed either a sequenced reverse-forward combustion technique (TS-2C) or a steam flooding procedure (TS-1 S) to recover in-place bitumen. This report documents the evaluation of activated carbon, ozone and reverse osmosis in treating the two types of tar sand wastewaters. Substrates included untreated and pretreated (filtration, foam fractionation, chemical treatment with ferric chloride) TS-1S and TS-2C wastewaters. Activated carbon, at a dose of 1,000 mg/L, reduced the Total Organic Carbon (TOC) of TS-1 S wastewater after treatment by 350 mg/L of ferric chloride to 2.3 mg/L TOC, a reduction of 91.6%. At the same adsorbent dos, activated carbon reduced the TOC in TS-2C wastewater from 678 mg/L to 546 mg/L. A study of the six commercially available adsorbents yielded little difference in adsorption capability for either wastewater. Ozonation of TS-lS wastewater after pretreatment by either foam fractionation or chemical treatment with ferric chloride then activated carbon yielded residual TOC levels of less than 1.2 mg/L. Reverse osmosis (RO) studies included investigation of four membrane types (cellulose acetate, poly-ether amide, poly-ether urea and a noncellulosic on a poly-sulfone base), three applied pressure levels (250, 400 and 550 psig) and two solution pH levels (5.5 and 7.8) with 5.0 µ (micron) filtered TS-2C wastewater as the substrate. A two-stage RO process achieved maximum organic and inorganic rejections of 98% and 97%, respectively.


2011 ◽  
Vol 412 ◽  
pp. 223-226 ◽  
Author(s):  
Wei Hui Jiang ◽  
Yan Hui Yang ◽  
Qing Xia Zhu ◽  
Jian Min Liu

ron-zircon pigment has been synthesized by non-hydrolytic sol-gel method using zirconium chloride and tetraethoxysilane as precursors, anhydrous ferric chloride as colorant, lithium fluoride as mineralizer and anhydrous ethanol as solvent. Iron-zircon pigment has been characterized by means of DTA-TG, XRD, Colorimeter and TEM. The results show that only a small fraction of iron is incorporated in the zircon crystal structure while the remaining iron cations are trapped within the zircon matrix. The iron-zircon with the red value (a*) of 20.64 can be synthesized at 700°C with the optimum Fe/Zr molar ratio of 0.2.


2016 ◽  
Vol 69 (9) ◽  
pp. 1054 ◽  
Author(s):  
Vincent Jamier ◽  
Eskender Mume ◽  
Cyril Papamicaël ◽  
Suzanne. V. Smith

New hexaazamacrobicyclic cage bi-functional chelators (BFCs), 1-N-(3-aminobenzyl)-3,6,10,13,16,19-hexaazabicyclo[6.6.6]eicosane-1,8-diamine (m-SarAr) and 1-N-(2-aminobenzyl)-3,6,10,13,16,19-hexaazabicyclo[6.6.6]eicosane-1,8-diamine (o-SarAr), were synthesised. Their complexation with selected transitions metal ions i.e. CuII, CoII, and CdII was investigated over a range of pH at micromolar concentrations. CuII was complexed by m-SarAr and o-SarAr rapidly within 5 min in pH range of 5–9 at ambient temperature. In contrast, the complexation of CoII and CdII by these ligands was slower. The conjugation efficiencies of p-SarAr, m-SarAr, and o-SarAr to bovine serum albumin (BSA) were compared under various reactions. Conditions were optimised to a molar ratio of BSA/N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide (EDC)/BFC of 1 : 250 : 50 in pH 5 buffer for 30 min at ambient temperature. Under these conditions, the average number of p-SarAr, m-SarAr, or o-SarAr attached to BSA were determined to be 2.21 ± 0.16, 4.90 × 10–1 ± 2.48 × 10–2, and 2.67 × 10–2 ± 2.67 × 10–3, respectively. This fundamental study clearly demonstrates that the position of the amine on the phenyl ring has a significant effect on the metal complexation and conjugation reactions with BSA.


REAKTOR ◽  
2018 ◽  
Vol 18 (2) ◽  
pp. 76 ◽  
Author(s):  
Srie Muljani ◽  
Bambang Wahyudi Wahyudi ◽  
S Suprihatin ◽  
Ketut Sumada

The synthesis of matrix silica-potassium-humic acid gel (Si-K-HAs) has been performed successfully by gradual extraction and acidification method. The extraction was carried out in two stages: 1) extraction of humic substances from peat prepared by potassium hydroxide to produce potassium humate (K-HAS) solution, 2) extraction silica from geothermal sludge using K-HAs solution to produce Si-K-HAs solution. Acidification of Si-K-HAs solution prepared by citric acid (1-3N) to produce matrix gel of Si-K-HAs. The Si-K-HAs matrix gel products are characterized by Fourier Transform InfraRed (FTIR), X-ray fluroscence (XRF), and Brunauer–Emmett–Teller (BET) analysis. The acidification process was carried out in neutral to acid (pH 3-7) conditions and the results showed that at neutral pH no Si-K-HAs gel formed. IR spectra confirmed the presence of humic acid in the gel product, whereas XRF analysis confirmed the presence of potassium (K) and silica (SiO2) in the gel product. The molar ratio of SiO2:K2O in the product is 0.9 - 0.3 in the pH range of 3-5. Si-K-HAs powder can be used as soil fertilizer especially for soils that lack silica, humic, and potassium nutrients or for future application development. Keywords: gradual extraction; geothermal sludge; matrix gel; humic substance


1984 ◽  
Vol 47 (1) ◽  
pp. 36-40 ◽  
Author(s):  
S. M. FLYNN ◽  
F. M. CLYDESDALE ◽  
O. T. ZAJICEK

Effective stability constants for cysteine and lysine with five different iron sources were evaluated along with their behavior in solution. The values obtained for ferric chloride-cysteine, ferrous sulfate-cysteine, ferric chloride-lysine, ferrous sulfate-lysine, hydrogen-reduced lysine, and electrolytic-reduced lysine were 6.81 × 102 to 2.78 × 103, 1.33 × 105 to 1.36 × 105, 6.00 × 10−4 to 7.64 × 10−3, 6.37 ×10−4 to 4.82× 10−3, 9.34 × 10−2 to 1.38 × 10−1, and 4.18 × 10−4 to 7.27 × 10−4, respectively. No measurable complexation occurred with hydrogen- and electrolytic-reduced iron with cysteine nor with ferric orthophosphate and cysteine or lysine. The stability of soluble ferric cysteine over the pH range 2.0 to 7.4 indicates that this complex has the potential to be used as an iron additive in food. Approximately half of the hydrogen and electrolytic reduced iron and only 0.11% of ferric orthophosphate were soluble in acid, whereas ferric chloride and ferrous sulfate were completely soluble. Qualitative evaluation of the iron-amino acid systems over a range of pH from 2.0 to 12.0 indicated that there was a mixed valence state of free iron in most cases with low pH favoring reduction and high pH oxidation, until precipitation of iron hydroxides occurred.


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