scholarly journals Application of Poly-γ-Glutamic Acid Flocculant to Flocculation–Sedimentation Treatment of Ultrafine Cement Suspension

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1748
Author(s):  
Tomokazu Yanagibashi ◽  
Motoyoshi Kobayashi ◽  
Keisuke Omori
Keyword(s):  
Ionic Strength ◽  
Glutamic Acid ◽  
Removal Efficiency ◽  
Control Charts ◽  
Removal Rate ◽  
Rapid Mixing ◽  
Mixing Intensity ◽  
The Relationship ◽  
Addition Amount ◽  
Ultrafine Cement

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.

Photocatalytic oxidation of chlorophenols in the presence of manganese ions

1999 ◽  
Vol 39 (10-11) ◽  
pp. 225-230 ◽  
Author(s):  
Jong-Nan Chen ◽  
Yi-Chin Chan ◽  
Ming-Chun Lu
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Photocatalytic Oxidation ◽  
Reaction Rate ◽  
Removal Rate ◽  
Adsorption Rate ◽  
Manganese Ions ◽  
Manganese Ion ◽  
Cp Decomposition ◽  
The Relationship

The decomposition of chlorophenols in aqueous solution with UV-illuminated TiO2 suspensions in the presence of manganese ions was studied. It was found that the removal rate of chlorophenols would be the highest at pH 3 in the presence of 1.18×10−4 M manganese ion. The effect of ionic strength on the 2-CP decomposition can be ignored in the range from 0.1 to 0.005 M for NaClO4. This study is also to explore the relationship between the adsorption rate and reaction rate. Results showed that the more the adsorption rate the more the decomposition rate for the three chlorophenols. Manganese ions can increase the photocatalytic oxidation of 2-chlorophenol in terms of DOC. The relationship between temperature and reaction rate for 2-CP is k = 0.0043T - 1.2146.

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
Keyword(s):  
Glutamic Acid ◽  
Adsorption Capacity ◽  
Metal Concentration ◽  
Removal Efficiency ◽  
Turning Point ◽  
Removal Rate ◽  
Metal Adsorption ◽  
Optimal Result ◽  
Environmental Friendly ◽  
Maximum Removal

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.

Studies the Factors of the Simultaneous Removal of Nitrogen and Carbon on Membrane Aeration Bioreactor

2013 ◽  
Vol 663 ◽  
pp. 403-408
Author(s):  
Wen Jie Li ◽  
Yun Wu ◽  
Hui Jia
Keyword(s):  
Dissolved Oxygen ◽  
Removal Efficiency ◽  
Removal Rate ◽  
Ammonia Nitrogen ◽  
Transmembrane Pressure ◽  
Simultaneous Removal ◽  
Membrane Aeration ◽  
Point Pressure ◽  
The Relationship ◽  
Oxygen Supply Rate

A Membrane aerated bioreactor (MABR) capable of simultaneous nitrification and denitrification in a single reactor vessel was developed to investigate the factors of the simultaneous removal of nitrogen and carbon. The results showed that when the bubble point pressure of membrane modules is 25kPa, the relationship between oxygenation efficiency and intransmembrane pressure were not positively correlated, controlling the transmembrane pressure was 15kPa, oxygen supply rate (OSR) was the highest. During the earlier stage of operation, reducing the hydraulic retention time of MABR could improve the integral removal efficiency, when the HRT was 2h, the removal of COD and ammonia - nitrogen were respectively 70.29% and 52.3%. The dissolved oxygen in the reactor had a significant influence, with the dissolved oxygen （DO） concentration about 0.5mg/L, ammonia-nitrogen and total nitrogen removal efficiency was better, the removal rate were 79.5% and 63% respectively. The reaction tank had CO2 accumulation, and caused pH reduced to 5.8, the operation should maintain the pH at 7.5 by increasing the alkalinity of the raw water.

Study on De-Nitrification of Improved Step-Feed Progress

2014 ◽  
Vol 703 ◽  
pp. 171-174
Author(s):  
Bing Wang ◽  
Yi Xiao ◽  
Shou Hui Tong ◽  
Lan Fang ◽  
Da Hai You ◽  
...  
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Fluidized Bed ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Operating Conditions ◽  
Removal Mechanism ◽  
Aerobic Zone

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.

scholarly journals Unfolding of Helical Poly(L-Glutamic Acid) in N,N-Dimethylformamide Probed by Pyrene Excimer Fluorescence (PEF)

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1690
Author(s):  
Weize Yuan ◽  
Remi Casier ◽  
Jean Duhamel
Keyword(s):  
Glutamic Acid ◽  
Local Density ◽  
Guanidine Hydrochloride ◽  
Racemic Mixture ◽  
Excimer Fluorescence ◽  
Excimer Formation ◽  
Blob Model ◽  
Α Helix ◽  
The Relationship ◽  
Pyrene Excimer Formation

The denaturation undergone by α–helical poly(L-glutamic acid) (PLGA) in N,N-dimethylformamide upon addition of guanidine hydrochloride (GdHCl) was characterized by comparing the fluorescence of a series of PLGA constructs randomly labeled with the dye pyrene (Py-PLGA) to that of a series of Py-PDLGA samples prepared from a racemic mixture of D,L-glutamic acid. The process of pyrene excimer formation (PEF) was taken advantage of to probe changes in the conformation of α–helical Py-PLGA. Fluorescence Blob Model (FBM) analysis of the fluorescence decays of the Py-PLGA and Py-PDLGA constructs yielded the average number (<Nblob>) of glutamic acids located inside a blob, which represented the volume probed by an excited pyrenyl label. <Nblob> remained constant for randomly coiled Py-PDLGA but decreased from ~20 to ~10 glutamic acids for the Py-PLGA samples as GdHCl was added to the solution. The decrease in <Nblob> reflected the decrease in the local density of PLGA as the α–helix unraveled in solution. The changes in <Nblob> with GdHCl concentration was used to determine the change in Gibbs energy required to denature the PLGA α–helix in DMF. The relationship between <Nblob> and the local density of macromolecules can now be applied to characterize the conformation of macromolecules in solution.

Investigation of the Water Guided Laser Micro-Jet Machining of Aero Engine Components

2017 ◽  
Author(s):  
Zhigang Wang
Keyword(s):  
Energy Density ◽  
Material Removal ◽  
Removal Rate ◽  
Cutting Speed ◽  
Potential Method ◽  
Laser Machining ◽  
Aero Engine ◽  
Engine Components ◽  
The Relationship ◽  
Dual Laser

The water guided laser micro-jet (LMJ) is a new potential method to machine aero engine parts with much less heat affected area and faster cutting speed than dry laser machining. The focus of this paper is to investigate the energy density and material removal for a dual-laser LMJ system. Then, the effects of dominated parameters on the energy density of LMJ are analyzed. Finally, a mathematical model is developed to describe the relationship between dominant laser parameters with the energy density of LMJ and material removal rate followed by machining case studies of aero engine components.

Start-Up of A2/O Humic Activated Sludge Systemphosphorus Removal Efficiency Analysis

2010 ◽  
Vol 113-116 ◽  
pp. 2201-2207 ◽  
Author(s):  
Jun Yin ◽  
Lei Wu ◽  
Ke Zhao ◽  
Yu Juan Yu
Keyword(s):  
Activated Sludge ◽  
Removal Efficiency ◽  
Phosphorus Removal ◽  
Removal Rate ◽  
Phosphorus Uptake ◽  
Phosphorus Release ◽  
Activated Sludge System ◽  
Start Up ◽  
Article Analysis ◽  
Sludge Activity

In this article, analysis the start-up of A2/O humic activated sludge system phosphorus removal efficiency and the characteristics of anaerobic phosphorus release, aerobic phosphorus uptake, sludge activity and their change in the Series Technologies process. The results show that A2/O humic activated sludge system phosphorus removal rate stabilized at 90.7% ~ 97.6%. Sludge activity except for anoxic zone 2 increased, along the process showed a gradual decrease trend.

Treatment of local scrubber wastewater for semiconductor by using photo-catalytic ozonation

2009 ◽  
Vol 59 (11) ◽  
pp. 2281-2286 ◽  
Author(s):  
Chung-Yi Chou ◽  
Chien-Pin Huang ◽  
Neng-Chou Shang ◽  
Yue-Hwa Yu
Keyword(s):  
Ion Exchange ◽  
Removal Efficiency ◽  
Removal Rate ◽  
Catalytic Ozonation ◽  
Acidic Condition ◽  
Buffer Solution ◽  
Toc Removal ◽  
Pre Treatment ◽  
Alkaline Buffer Solution

This study investigates the oxidation of local scrubber wastewater (LSW) from semiconductor manufacture by using ozonation, catalytic ozonation (ozone/Al2O3 and ozone/TiO2–Al2O3), and photo-catalytic ozonation (UV/TiO2–Al2O3, ozone/UV and ozone/UV/TiO2–Al2O3). The results show that catalyst Al2O3 and TiO2–Al2O3 promotes the TOC removal under the condition of neutral or alkaline buffer solution during catalytic ozonation of LSW. The Al2O3 induces highest promotion in TOC removal efficiency, which is higher than ozone alone by 26% TOC removal under alkaline buffer solution. However, TiO2–Al2O3 and Al2O3 cannot display the promotion in TOC removal under acidic condition. In addition, a pre-treatment of anion ion-exchange is employed and the result indicates that decreasing the anion ions concentration before AOPs can imply higher TOC removal during AOPs of LSW. In this study, ozone/UV under raw LSW acidic condition and ozone/Al2O3 under alkaline buffer solution present 95% and 88% TOC removal rate respectively and show the higher TOC removal efficiency than other AOPs. Therefore, these two kinds of AOP can serve as the very viable AOP methods in the LSW reclamation for semiconductor.

COD removal efficiency and mechanism of HMBR in high volumetric loading for ship domestic sewage treatment

2016 ◽  
Vol 74 (7) ◽  
pp. 1509-1517 ◽  
Author(s):  
Linan Zhu ◽  
Hailing He ◽  
Chunli Wang
Keyword(s):  
Removal Efficiency ◽  
Removal Rate ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Domestic Sewage ◽  
Cod Removal ◽  
Aeration Tank ◽  
Remarkable Effect ◽  
Cod Removal Efficiency ◽  
Volumetric Loading

The hybrid membrane bioreactor (HMBR) has been applied in ship domestic sewage treatment under high volumetric loading for ship space saving. The mechanism and influence factors on the efficiency, including hydraulic retention time (HRT), dissolved oxygen (DO) of chemical oxygen demand (COD) removal were investigated. The HMBR's average COD removal rate was up to 95.13% on volumetric loading of 2.4 kgCOD/(m3•d) and the COD concentration in the effluent was 48.5 mg/L, far below the International Maritime Organization (IMO) discharge standard of 125 mg/L. DO had a more remarkable effect on the COD removal efficiency than HRT. In addition, HMBR revealed an excellent capability of resisting organics loading impact. Within the range of volumetric loading of 0.72 to 4.8 kg COD/(m3•d), the effluent COD concentration satisfied the discharge requirement of IMO. It was found that the organics degradation in the aeration tank followed the first-order reaction, with obtained kinetic parameters of vmax (2.79 d−1) and Ks (395 mg/L). The original finding of this study had shown the effectiveness of HMBR in organic contaminant degradation at high substrate concentration, which can be used as guidance in the full scale of the design, operation and maintenance of ship domestic sewage treatment devices.

scholarly journals Photoreduction of Cr(VI) Ions in Aqueous Solutions by UV/ Photocatalytic Processes

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Chih Ming Ma ◽  
Yung Shuen Shen ◽  
Po Hsiang Lin
Keyword(s):  
Aqueous Solutions ◽  
Reaction Rate ◽  
Removal Rate ◽  
Experimental Results ◽  
Order Kinetic ◽  
Solution Ph ◽  
Relationship Of ◽  
The Relationship ◽  
Photocatalytic Processes ◽  
Order Kinetic Equation

This study discussed the photoreduction of Cr(VI) ions in aqueous solutions by UV/TiO2photocatalytic processes under various operational factors. Experimental results showed that the removal rate of Cr(VI) increased with decreasing solution pH values and with increasing dosages of organic compounds, indicating that the recombination rate of electrons and h+can be retarded in the reaction systems by the addition of the scavenger, thus raising the reaction rate of Cr(VI). The relationship of the chemical reaction rate of Cr(VI), TiO2dosage, and changes of Cr(VI) concentration was expressed by the pseudo-first-order kinetic equation. Comparing the experimental results of two different doping metals in modified TiO2photoreduction systems, the removal rate of Cr(VI) by the Ag/TiO2process is larger, possibly because the electron transferring ability of Ag is superior to that of Cu. However, the photoreduction rates of Cr(VI) by modified UV/TiO2processes are worse than those by a nonmodified commercial UV/TiO2process.

Sign in / Sign up

Export Citation Format

Share Document