Phosphate removal and recovery by a novel electrolytic process

2002 ◽  
Vol 46 (11-12) ◽  
pp. 147-152 ◽  
Author(s):  
Y. Sakakibara ◽  
H. Nakajima
Keyword(s):  
Electric Current ◽  
Removal Rate ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Synthetic Wastewater ◽  
Bulk Liquid ◽  
Anode Surface ◽  
Electrolytic Process ◽  
Current Densities ◽  
Good Agreement

The possibility of removing and recovering phosphate from wastewater by a novel electrolytic process was investigated experimentally. In the process, ion electrodes are immersed in synthetic wastewater and direct current (DC) is applied to coagulate phosphate on the surface of the anode. Experimental results demonstrated that at electric current densities ranged from 0.001 to 0.1 mA/cm2, phosphate was removed and recovered as phosphate-rich aggregates formed on the anode surface. Decreases in phosphate concentration at bulk liquid were in fairly good agreement with the amounts of phosphate in the aggregates. Moreover, the removal rate of phosphate was increased with increasing electric current. In addition, as heavy metal anions such as Cu2+ deposit on the counter electrode (cathode), it was thought that relatively pure phosphate could be obtained by the present process.

scholarly journals Phosphate Removal Using Polyethylenimine Functionalized Silica-Based Materials

2021 ◽  
Vol 13 (3) ◽  
pp. 1502
Author(s):  
Maria Xanthopoulou ◽  
Dimitrios Giliopoulos ◽  
Nikolaos Tzollas ◽  
Konstantinos S. Triantafyllidis ◽  
Margaritis Kostoglou ◽  
...  
Keyword(s):  
Sorption Capacity ◽  
Removal Rate ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Equilibrium Studies ◽  
Maximum Sorption Capacity ◽  
Algae Blooms ◽  
Maximum Sorption ◽  
Phosphate Anions ◽  
Adsorbent Dose

In water and wastewater, phosphate anions are considered critical contaminants because they cause algae blooms and eutrophication. The present work aims at studying the removal of phosphate anions from aqueous solutions using silica particles functionalized with polyethylenimine. The parameters affecting the adsorption process such as pH, initial concentration, adsorbent dose, and the presence of competitive anions, such as carbonate, nitrate, sulfate and chromate ions, were studied. Equilibrium studies were carried out to determine their sorption capacity and the rate of phosphate ions uptake. The adsorption isotherm data fitted well with the Langmuir and Sips model. The maximum sorption capacity was 41.1 mg/g at pH 5, which decreased slightly at pH 7. The efficiency of phosphate removal adsorption increased at lower pH values and by increasing the adsorbent dose. The maximum phosphate removal was 80% for pH 5 and decreased to 75% for pH 6, to 73% for pH 7 and to 70% for pH 8, for initial phosphate concentration at about 1 mg/L and for a dose of adsorbent 100 mg/L. The removal rate was increased with the increase of the adsorbent dose. For example, for initial phosphate concentration of 4 mg/L the removal rate increased from 40% to 80% by increasing the dose from 0.1 to 2.0 g/L at pH 7. The competitive anions adversely affected phosphate removal. Though they were also found to be removed to a certain extent. Their co-removal provided an adsorbent which might be very useful for treating waters with low-level multiple contaminant occurrence in natural or engineered aquatic systems.

Optimization of Crystallization of Magnesium Ammonium Phosphate: Initial Phosphate Concentration, PH and Reactants Molar Ratio

2013 ◽  
Vol 295-298 ◽  
pp. 1289-1292 ◽  
Author(s):  
Kai Huang ◽  
Li Ping Qiu ◽  
Jin Feng Meng ◽  
Dong Wang
Keyword(s):  
Ph Value ◽  
Removal Rate ◽  
Ammonium Phosphate ◽  
Xrd Analysis ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Molar Ratio ◽  
Septic Tank ◽  
Magnesium Ammonium Phosphate ◽  
Magnesium Ammonium

By- products are widespread in the crystallization of magnesium ammonia phosphate (MAP) as the differences in reactive conditions which effects the forms and habits of crystals. The study focused on the supernatant from septic tank in order to achieve in-situ treatment. Based on the effluent, the optimization research of initial phosphate concentration and pH was investigated by using single factor analysis. The crystal products with different reaction condition were also characteristiced through the XRD analysis. The experimental results showed that the optimum reactants molar ratio of n(NH4+):n(Mg2+):n(PO43-) were 90:25:1, 4:1.6:1 and 3:1.4:1 when pH value was 9.5 with initial phosphate concentration 8mg/L, 50mg/L and 100mg/L, respectively. It was also observed that the phosphate removal rate increased with increasing the initial phosphate concentration or pH value. As the aging time increased, the removal rate was in parabolic curve with 30 minute at the highest point. The XRD analysis revealed that the best MAP crystal could be produced with initial phosphate concentration 50mg/L and pH 9.0.

Ureolytic phosphate precipitation from anaerobic effluents

2009 ◽  
Vol 59 (10) ◽  
pp. 1983-1988 ◽  
Author(s):  
E. Desmidt ◽  
W. Verstraete ◽  
J. Dick ◽  
B. D. Meesschaert ◽  
M. Carballa
Keyword(s):  
Hydraulic Retention Time ◽  
Ph Value ◽  
Continuous Operation ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Synthetic Wastewater ◽  
Processing Industry ◽  
Operational Conditions ◽  
Constant Ph ◽  
High Concentrations

In this work, the elimination of phosphate from industrial anaerobic effluents was evaluated at lab-scale. For that purpose, the ureolytic method previously developed for the precipitation of Ca2 +  from wastewater as calcite was adapted for the precipitation of phosphate as struvite. In the first part of the study, computer simulations using MAPLE and PHREEQC were performed to model phosphate precipitation from wastewater as struvite. The results obtained showed that relative high concentrations of ammonium and magnesium are needed to precipitate phosphate as struvite. The total molar concentrations ratio of Mg2 + :PO43−-P:NH4+ required to decrease PO43−-P concentrations from 20 to 6 mg PO43−-P/l at pH 8.4-8.5 was estimated on 4.6:1:8. In the second part of the study, lab-scale experiments with either synthetic wastewater or the anaerobic effluent from a vegetable processing industry were carried out in batch and continuous mode. Overall, the continuous operation at a hydraulic retention time (HRT) of 2.4 h and an added molar concentration [Mg2 + ]:[PO43−-P]:[NH4+] ratio of 1.6:1:2.3 resulted in a constant pH value in the reactor (around 8.5) and an efficient phosphate removal (>90%) to residual levels of 1–2 mg PO43−-P/l. Different operational conditions, such as the initial phosphate concentration, HRT and the use of CaCl2 or MgO instead of MgCl2, were analysed and the performance of the reactor was satisfactory under a broad range of them. Yet, overall, optimal results (higher phosphate removal) were obtained with MgCl2.

One-Pot Synthesis of Mesoporous MCM-41 with Different Functionalization Levels and their Adsorption Abilities to Phosphate

2012 ◽  
Vol 476-478 ◽  
pp. 1969-1973 ◽  
Author(s):  
Wei Ya Huang ◽  
Jun Yang ◽  
Yuan Ming Zhang
Keyword(s):  
Removal Rate ◽  
Langmuir Model ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Phosphate Adsorption ◽  
Experiment Data ◽  
Sorption Equilibrium ◽  
One Pot ◽  
Adsorption Capacities ◽  
Mcm 41

Ethylenediamine (EDA) functionalized mesoporous MCM-41 particles displaying various functionalization levels have been prepared by one-pot method. The prepared samples were treated with Fe(III) to form cationic complexes inside MCM-41 pores (MCM-41-NN-Fe-x%, x=10, 20 and 30) for trapping phosphate from water. The prepared adsorbents were characterized by XRD, BET, TGA and elemental analysis, and their phosphate adsorption performances were studied. The results showed that the phosphate removal rate of all the prepared adsorbents were higher than 95% at the initial phosphate concentration of 2 ppm. Additionally, the Langmuir model was used to simulate the sorption equilibrium, and the results indicated that the experiment data agreed well with the Langmuir model. The maximum adsorption capacities calculated from the Langmuir model increased with the increase of diamino loadings in adsorbents, and the maximum adsorption capacities of MCM-41-NN-Fe-30% was 52.5 mg/g.

Eco-friendly removal of phosphate from aqueous solution using natural dietary fibers and minerals

2018 ◽  
Vol 32 (19) ◽  
pp. 1840075
Author(s):  
Ho Hong Quyen ◽  
Maki Yoshioka ◽  
Masashi Kurashina ◽  
Mikito Yasuzawa ◽  
Le Thi Xuan Thuy
Keyword(s):  
Aqueous Solution ◽  
Filter Paper ◽  
Adsorption Process ◽  
Alginic Acid ◽  
Removal Rate ◽  
Membrane Filter ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Dietary Fibers ◽  
Particle Retention

In this study, we focused on the investigation of phosphate removal using calcium oxide (CaO) and calcium hydroxide (Ca(OH)2) which are mainly from the calcined shells as adsorbents. Hydroxylapatite Ca[Formula: see text](PO4)6(OH)2, the component of industrial fertilizer was formed after the adsorption process following the XRD results. The phosphate removal increased from 20% to 97% with the aid of the mixture of flocculants alginic acid (AA), NaHCO3 and CaCl[Formula: see text] 2H2O in the case of 50 ppm phosphate concentration when the samples were filtered through 2.7 [Formula: see text]m particle retention filter paper which is roughly equivalent to the case of phosphate removal rate of 0.2 [Formula: see text]m membrane filter paper without flocculants (99%). The results suggest that AA, NaHCO3 and CaCl[Formula: see text]2H2O as the flocculants are effective for phosphate removal from 20 to 100 ppm.

scholarly journals Enhanced removal of phosphate from wastewater by precipitation coupled with flocculation

2021 ◽  
pp. 5-10
Author(s):  
Ho Hong Quyen Ho
Keyword(s):  
Removal Efficiency ◽  
Filter Paper ◽  
Alginic Acid ◽  
Weight Ratio ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Synthetic Wastewater ◽  
Phosphate Solution

Eco-friendly flocculants of alginic acid, NaHCO3 and CaCl2.2H2O with advantages of strong gelation characteristics were prepared for supporting the removal of phosphate in synthetic wastewater using CaO and Ca(OH)2 as precipitants. The effects of weight ratios of each component in flocculants, dosage of flocculants and initial phosphate concentration were investigated through batch of experiments. The results showed excellent flocculation performance with the weight ratio of alginic acid:NaHCO3 and CaCl2.2H2O at 1:0.3:0.02 and the dosage of flocculants at 0.0050 g/25 mL of phosphate solution in the range of initial phosphate concentration from 50 to 1000 ppm. Comparing to the sample without flocculants, the phosphate removal efficiency using CaO and Ca(OH)2 with the addition of flocculants increased from 19 and 20% to 97% at the initial phosphate concentration of 50 ppm, respectively by filtration of filter paper 2.7 μm.

scholarly journals Bioaugmentation with Bacillus spp. for bioremediation of synthetic wastewater using a fluidized-bed reactor

2020 ◽  
Author(s):  
◽  
Yrielle Roets ◽  
Keyword(s):  
Wastewater Treatment ◽  
Fluidized Bed ◽  
Flow Rate ◽  
Retention Time ◽  
Removal Rate ◽  
Phosphate Removal ◽  
Synthetic Wastewater ◽  
Biological Wastewater Treatment ◽  
Ammonium Removal ◽  
Bacillus Spp

South Africa’s freshwater resources, including rivers, man-made lakes and groundwater are under severe threat due to an ever-expanding population and economy, which is depleting these resources. The increase in population has a direct correlation with the increase in wastewater generated. The remaining fresh water resources need to be preserved therefore recycling of wastewater, to replenish our water supplies and preserve the environment, is a solution to the problem. For a developing country, it is important to use treatment methods that are cost effective and do not exert a negative impact on the environment, such as biological wastewater treatment options. One of the systems commonly used in biological wastewater treatment is the fluidized-bed bioreactor (FBBR) due to its advantages such as higher biomass concentration and a higher mass transfer thus resulting in a higher rate of biodegradation. This study focused on evaluating the efficacy of augmenting with Bacillus spp. to enhance the bioremediation of wastewater using a FBBR. Bacillus spp. used in this study were isolated from a municipal wastewater treatment plant (10 isolates) and the remaining three isolates were selected from the CSIR Bacillus database. The isolates (13 in total) were screened for 1) their ability grow in wastewater, 2) ability to reduce high concentrations of COD, ammonium, nitrates and phosphates in flask studies containing synthetic wastewater (SWW) and 3) ability to produce common enzymes such as amylase, cellulase, lipase and protease. Isolates showed varying bioremediation potential for different compounds analysed. Isolate B006 showed the highest phosphate removal rate (3.290 mg.L-1.h-1) where as D005 showed the highest growth rate (0.955 h-1), COD reduction rate (55 mg.L-1.h-1) and cellulase activity (5.485 mm) among all the isolates. Isolate D014 presented the highest ammonium removal rate (12.43 mg.L-1.h-1), amylase (5.00 mm) and protease (10.00 mm) activity whilst B001 displayed the highest nitrate removal rate (9.4 mg.L-1.h-1). The results for the individual assays were assessed and weighted in a matrix and the isolates that scored above 50% were selected for consortium studies. Four Bacillus spp. that scored above 50% in the scoring matrix were then evaluated for their ability to co-exist as a consortium. The consortium studies were then compared with results obtained for individual isolates. The selected Bacillus isolates were identified and assessed for their safety to the environment and to the end user. Identification was conducted using 16s rDNA sequencing and results showed that B006 identified as B. cereus, D005 as B. cereus and D014 as B. subtilis. Isolates, B006 and D005 were further assessed for enterotoxin production and the presence of anthrax virulent plasmids pX01 and pX02. After conducting the biosafety assays, the isolates were rendered safe for use. The isolates were then cryopreserved as spores in 25% glycerol and stored at -80 °C. The impact of the cryopreservation method and the storage conditions on the viability of the isolates was assessed after six months of storage and it was established that the isolates were still viable and that the method was adequate. The bioremediation potential of the consortium was further evaluated using a 17 L Pilot scale fluidised-bed bioreactor. The reactors were fed at three different flow rates of 1.5 L.h-1, 2 L.h-1 and 3 L.h-1 over steady state conditions (~3months). The results showed that the FBBR augmented with the selected Bacillus isolates, resulted in improved nutrient (COD, ammonium and phosphates) removal efficiencies compared to the non-bioaugmented control. The highest ammonium removal (62.8%) was observed at a flow rate of 1.5 L.h-1 (11.30 h retention time), whereby there was an overall 29.8% improvement in ammonia removal in comparison to the non-augmented control. Similarly, an overall improvement in phosphate (14.73%) was observed at a flow rate of 2 L.h-1 (8.48 h retention time) with 50% removal efficiency. The highest COD removal was observed at a flow rate of 1.5 L.h-1 (11.30 h retention time) whereby 74.5% COD was reduced with a 32.6% improvement when compared to the non-bioaugmented control. Our work has demonstrated the potential application of Bacillus as bioaugmentation agents to enhance wastewater treatment efficiency as a potential solution to water challenges in developing countries. This technology could also be utilized for addressing the challenges of a wider range of different effluents.

OPTIMIZATION OF PHOSPHATE REMOVAL FROM SYNTHETIC WASTEWATER BY BACTERIAL CONSORTIUM USING BOX-BEHNKEN DESIGN

2013 ◽  
Vol 12 (12) ◽  
pp. 2371-2383
Author(s):  
Krishnaswamy Usharani ◽  
Perumalsamy Lakshmanaperumalsamy ◽  
Muthusamy Muthukumar
Keyword(s):  
Bacterial Consortium ◽  
Phosphate Removal ◽  
Synthetic Wastewater ◽  
Box Behnken Design

Hydrolysis of organic wastewater particles in laboratory scale and pilot scale biofilm reactors under anoxic and aerobic conditions

1998 ◽  
Vol 38 (8-9) ◽  
pp. 179-188 ◽  
Author(s):  
K. F. Janning ◽  
X. Le Tallec ◽  
P. Harremoës
Keyword(s):  
Organic Matter ◽  
Mass Balance ◽  
Particulate Organic Matter ◽  
Removal Rate ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
Synthetic Wastewater ◽  
Aerobic Conditions ◽  
Biofilm Reactors ◽  
Hydrolysis Of

Hydrolysis and degradation of particulate organic matter has been isolated and investigated in laboratory scale and pilot scale biofilters. Wastewater was supplied to biofilm reactors in order to accumulate particulates from wastewater in the filter. When synthetic wastewater with no organic matter was supplied to the reactors, hydrolysis of the particulates was the only process occurring. Results from the laboratory scale experiments under aerobic conditions with pre-settled wastewater show that the initial removal rate is high: rV, O2 = 2.1 kg O2/(m3 d) though fast declining towards a much slower rate. A mass balance of carbon (TOC/TIC) shows that only 10% of the accumulated TOC was transformed to TIC during the 12 hour long experiment. The pilot scale hydrolysis experiment was performed in a new type of biofilm reactor - the B2A® biofilter that is characterised by a series of decreasing sized granular media (80-2.5 mm). When hydrolysis experiments were performed on the anoxic pilot biofilter with pre-screened wastewater particulates as carbon source, a rapid (rV, NO3=0.7 kg NO3-N/(m3 d)) and a slowler (rV, NO3 = 0.3 kg NO3-N/(m3 d)) removal rate were observed at an oxygen concentration of 3.5 mg O2/l. It was found that the pilot biofilter could retain significant amounts of particulate organic matter, reducing the porosity of the filter media of an average from 0.35 to 0.11. A mass balance of carbon shows that up to 40% of the total incoming TOC accumulates in the filter at high flow rates. Only up to 15% of the accumulated TOC was transformed to TIC during the 24 hour long experiment.

scholarly journals Modification and Validation of the Phosphate Removal Model: A Multicenter Study

2021 ◽  
pp. 1-10
Author(s):  
Weichen Zhang ◽  
Qiuna Du ◽  
Jing Xiao ◽  
Zhaori Bi ◽  
Chen Yu ◽  
...  
Keyword(s):  
Polynomial Regression ◽  
External Validation ◽  
Original Model ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Internal Validation ◽  
Modified Model ◽  
New Model ◽  
Significant Difference ◽  
Removal Model

<b><i>Background:</i></b> Our research group has previously reported a noninvasive model that estimates phosphate removal within a 4-h hemodialysis (HD) treatment. The aim of this study was to modify the original model and validate the accuracy of the new model of phosphate removal for HD and hemodiafiltration (HDF) treatment. <b><i>Methods:</i></b> A total of 109 HD patients from 3 HD centers were enrolled. The actual phosphate removal amount was calculated using the area under the dialysate phosphate concentration time curve. Model modification was executed using second-order multivariable polynomial regression analysis to obtain a new parameter for dialyzer phosphate clearance. Bias, precision, and accuracy were measured in the internal and external validation to determine the performance of the modified model. <b><i>Results:</i></b> Mean age of the enrolled patients was 63 ± 12 years, and 67 (61.5%) were male. Phosphate removal was 19.06 ± 8.12 mmol and 17.38 ± 6.75 mmol in 4-h HD and HDF treatments, respectively, with no significant difference. The modified phosphate removal model was expressed as Tpo<sub>4</sub> = 80.3 × <i>C</i><sub>45</sub> − 0.024 × age + 0.07 × weight + β × clearance − 8.14 (β = 6.231 × 10<sup>−3</sup> × clearance − 1.886 × 10<sup>−5</sup> × clearance<sup>2</sup> – 0.467), where <i>C</i><sub>45</sub> was the phosphate concentration in the spent dialysate measured at the 45th minute of HD and clearance was the phosphate clearance of the dialyzer. Internal validation indicated that the new model was superior to the original model with a significantly smaller bias and higher accuracy. External validation showed that <i>R</i><sup>2</sup>, bias, and accuracy were not significantly different than those of internal validation. <b><i>Conclusions:</i></b> A new model was generated to quantify phosphate removal by 4-h HD and HDF with a dialyzer surface area of 1.3–1.8 m<sup>2</sup>. This modified model would contribute to the evaluation of phosphate balance and individualized therapy of hyperphosphatemia.

Sign in / Sign up

Export Citation Format

Share Document