Removal Efficiency of Lead (II) by a Biopolymer Poly-y-Glutamic Acid

2011 ◽  
Vol 94-96 ◽  
pp. 995-998 ◽  
Author(s):  
Rui Min Mu ◽  
Gui Xia Ma ◽  
Xia Zhao

Lead(Ⅱ) is a typical industrial pollutant which is harmful to people’s health. In this study, a new environmental-friendly material, the edible biopolymer poly--glutamic acid (-PGA) was applied to adsorb lead(Ⅱ). The results revealed that -PGA had pronounced binding effects on lead(Ⅱ) and its metal adsorption capacity was affected by lead(Ⅱ) concentration, -PGA dose and pH of the solution. For lead(Ⅱ) concentration, the removal rate of lead(Ⅱ) increased with the decrease of the metal concentration. For -PGA dose, the removal rate of lead(Ⅱ) increased with the increase of -PGA dose until the turning point at 4000 mg/L and then the tendency was adverse. The maximum removal rate was 92.8 % when lead(Ⅱ) and -PGA concentration was 1000 mg/L and 4000 mg/L separately. For pH, the metal adsorption capacity was weak when pH<4 and the optimal result occurred at pH 5-6.

2011 ◽  
Vol 340 ◽  
pp. 236-240
Author(s):  
Jian Feng Ma ◽  
Jian Ming Yu ◽  
Bing Ying Cui ◽  
Ding Long Li ◽  
Juan Dai

Inorganic-organic-bentonite was synthesized by modification of bentonite by Hydroxy-iron and surfactant, which could be applied in dye removal by adsorption and catalysis. The removal of acid dye Orange II was studied at various factors such as time and pH of solution. The results showed that the inorganic-organic-bentonite could efficiently remove the dye with efficiency of 96.22%. The maximum adsorption capacity is 76 mg/g. The pH of solution has significant effect on both adsorption and catalysis. When pH was 4, the maximum removal efficiency of adsorption and catalysis were 97.57% and 87.23%, respectively. After degradation, the secondary pollution was diminished and the bentonite could be reused.


Using modified macadamia carbon by H2O2 as adsorbent to remove Zn2+ with H2O2 25% in 48 hours. The Parameters, such as pH, dosage and adsorption time affect the processing ability of modified macadamia carbon H2O2. The maximum removal efficiency of 64.52% was obtained at a pH of 4.5, the processing time is 80 minutes, dosage 1.8 g/L and an initial heavy metal concentration of 25ppm.


2013 ◽  
Vol 48 (2) ◽  
pp. 121-132 ◽  
Author(s):  
S. Piel ◽  
S. Blondeau ◽  
J. Pérot ◽  
E. Baurès ◽  
O. Thomas

The adsorption of some major pharmaceutical products (sulfamethoxazole, caffeine, iopromide and carbamazepine) in water was evaluated using four types of activated carbon, three powdered activated carbon (PAC) and one fluidized, coagulated and flocculated activated carbon (FAC) extracted from a Carboplus®P pilot. These substances were the most frequently quantified (in 50% of samples at least) in surface waters of the Vilaine's basin (Brittany, France) during three sampling campaigns. Jar test experiments were carried out in order to assess the removal efficiency of the four activated carbons. Carbamazepine and caffeine were well removed with PAC with a maximum removal rate of 80% whereas it was more difficult for sulfamethoxazole and iopromide with a maximum of 39%. For each molecule, removal rates are clearly dependent on PAC nature. The overall results with FAC are clearly distinguishable from PAC tests with gains of performance on all target molecules (from 80 to &gt;95%).


2019 ◽  
Vol 20 (2) ◽  
pp. 1-9
Author(s):  
Abeer I. Alwared ◽  
Nada Abdulrazzaq ◽  
Baseem Al-Sabbagh

In this work, microbubble dispersed air flotation technique was applied for cadmium ions removal from wastewater aqueous solution. Experiments parameters such as pH (3, 4, 5, and 6), initial Cd(II) ions concentration (40, 80, and 120 mg/l)  contact time( 2, 5, 10 , 15, and 20min), and surfactant (10, 20and 40mg/l) were studied in order to optimize the best conditions .The experimental results indicate that microbubbles were quite effective in removing cadmium ions and the anionic surfactant SDS was found to be more efficient than cationic CTAB in flotation process. 92.3% maximum removal efficiency achieved through 15min at pH 5, SDS surfactant concentration 20mg/l, flow rate250 cm3/min and at 40mg/l Cd(II) ions initial concentration. The removal efficiency of cadmium ion was predicted through 11 neurons hidden layer, with a correlation coefficient of 0.9997 between ANN outputs and the experimental data and through sensitivity analysis, pH was found to be most significant parameter (25.13 %).The kinetic flotation order for cadmium ions almost first order and the removal rate constant (k) increases with decreasing the initial metal concentration.


Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1748
Author(s):  
Tomokazu Yanagibashi ◽  
Motoyoshi Kobayashi ◽  
Keisuke Omori

We examined the effect of poly-γ-glutamic acid flocculant (PGAF) on the removal of ultrafine cement (UFC) particles stabilized by a poly-carboxylate co-polymer, which is a superplasticizer (SP). The flocculation–sedimentation treatment with PGAF successfully removed the SP-stabilized cement particles through the gravitational settling of the formed flocs. The removal efficiency reduced with the increase in the ionic strength, probably because of the shrunk form of poly-γ-glutamic acid (γ-PGA) at high ionic strengths. Increasing the mixing intensity during rapid mixing improved the removal efficiency. A series of flocculation–sedimentation experiments provided a diagram showing the relationship between ionic strengths and the addition amount of PGAF. Our results suggest that PGAF is a good candidate for the purification of cement suspension by flocculation–sedimentation, and a better removal performance can be obtained at lower ionic strengths with intense rapid mixing. From the diagram of the control charts presented in this study, we can determine the optimal addition amount of PGAF for achieving the target removal rate for cement suspension under any ionic strength.


2021 ◽  
Vol 13 (15) ◽  
pp. 8552
Author(s):  
Vahid Alimohammadi ◽  
Mehdi Maghfouri ◽  
Delaram Nourmohammadi ◽  
Pejman Azarsa ◽  
Rishi Gupta ◽  
...  

Clean water is a vital need for all living creatures during their lifespan. However, contaminated stormwater is a major issue around the globe. A wide range of contaminants, including heavy metals, organic and inorganic impurities, has been discovered in stormwater. Some commonly utilized methods, such as biological, physical and chemical procedures, have been considered to overcome these issues. However, these current approaches result in moderate to low contaminant removal efficiencies for certain classes of contaminants. Of late, filtration and adsorption processes have become more featured in permeable concretes (PCs) for the treatment of stormwater. As nanoparticles have vast potential and unique characterizations, such as a higher surface area to cure polluted stormwater, employing them to improve permeable concretes’ capabilities in stormwater treatment systems is an effective way to increase filtration and adsorption mechanisms. The present study reviews the removal rate of different stormwater contaminants such as heavy metals, organic and other pollutants using nanoparticle-improved PC. The application of different kinds of nanomaterials in PC as porous media to investigate their influences on the properties of PC, including the permeability rate, compressive strength, adsorption capacity and mix design of such concrete, was also studied. The findings of this review show that different types of nanomaterials improve the removal efficiency, compressive strength and adsorption capacity and decrease the infiltration rate of PC during the stormwater treatment process. With regard to the lack of comprehensive investigation concerning the use of nanomaterials in PC to treat polluted stormwater runoff, this study reviews 242 published articles on the removal rate of different stormwater contaminants by using PC improved with nanoparticles.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2741
Author(s):  
Pengcheng Lv ◽  
Ruihong Meng ◽  
Zhongyang Mao ◽  
Min Deng

In this study, the hydrated sodium aluminosilicate material was synthesized by one-step hydrothermal alkaline desilication using fly ash (FA) as raw material. The synthesized materials were characterized by XRD, XRF, FT-IR and SEM. The characterization results showed that the alkali-soluble desilication successfully had synthesized the sodium aluminosilicate crystalline (N-A-S-H) phase of sodalite-type (SOD), and the modified material had good ionic affinity and adsorption capacity. In order to figure out the suitability of SOD as an adsorbent for the removal of ammonium and phosphorus from wastewater, the effects of material dosing, contact time, ambient pH and initial solute concentration on the simultaneous removal of ammonium and phosphorus are investigated by intermittent adsorption tests. Under the optimal adsorption conditions, the removal rate of ammonium was 73.3%, the removal rate of phosphate was 85.8% and the unit adsorption capacity reached 9.15 mg/L and 2.14 mg/L, respectively. Adsorption kinetic studies showed that the adsorption of ammonium and phosphorus by SOD was consistent with a quasi-secondary kinetic model. The adsorption isotherm analysis showed that the equilibrium data were in good agreement with the Langmuir and Freundlich model. According to thermodynamic calculations, the adsorption of ammonium and phosphorus was found to be a heat-absorbing and spontaneous process. Therefore, the preparation of SOD by modified FA has good adsorption properties as adsorbent and has excellent potential for application in the removal of contaminants from wastewater.


Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 512
Author(s):  
Jeremiah Chimhundi ◽  
Carla Hörstmann ◽  
Evans M. N. Chirwa ◽  
Hendrik G. Brink

The main objective of this study was to achieve the continuous biorecovery and bioreduction of Pb(II) using an industrially obtained consortia as a biocatalyst. An upflow anaerobic sludge blanket reactor was used in the treatment process. The bioremediation technique that was applied made use of a yeast extract as the microbial substrate and Pb(NO3)2 as the source of Pb(II). The UASB reactor exhibited removal efficiencies of between 90 and 100% for the inlet Pb concentrations from 80 to 2000 ppm and a maximum removal rate of 1948.4 mg/(L·d) was measured. XRD and XPS analyses of the precipitate revealed the presence of Pb0, PbO, PbS and PbSO4. Supporting experimental work carried out included growth measurements, pH, oxidation–reduction potentials and nitrate levels.


2014 ◽  
Vol 703 ◽  
pp. 171-174
Author(s):  
Bing Wang ◽  
Yi Xiao ◽  
Shou Hui Tong ◽  
Lan Fang ◽  
Da Hai You ◽  
...  

Improved step-feed de-nitrification progress combined with biological fluidized bed was introduced in this study. The progress had good performance and capacity of de-nitrification and organic matter. The experiment result showed that the de-nitrification efficiency of the improved biological fluidized bed with step-feed process was higher than the fluidized bed A/O process under the same water quality and the operating conditions. When the influent proportion of each segment was equal, the system showed good nitrogen removal efficiency with the change of influent C/N ratio, HRT and sludge return ratio. The removal rate of TN reached up to 88.2%. It showed that the simultaneous nitrification and de-nitrification phenomenon happened in the aerobic zone. The nitrogen removal mechanism was also studied.


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