scholarly journals Thermal aging of heteroatom substituted Keggin type aluminum oxo polycation solutions: Aggregation behavior and impacts on dissolved organic carbon and turbidity removal

2021 ◽  
Author(s):  
Mohammad Shohel ◽  
Jack A. Smith ◽  
Margaret A. Carolan ◽  
Tori Z. Forbes
Keyword(s):  
Water Treatment ◽  
High Efficiency ◽  
Solution Stability ◽  
Contaminant Removal ◽  
Hydrothermal Aging ◽  
Turbidity Removal ◽  
Keggin Type ◽  
Aging Studies ◽  
Ph Range ◽  
Hydrolysis Of

Coagulation processes within water treatment plays an important role in contaminant removal and aluminum-oxo Keggin polycations are proved to be an effective coagulating agents. Previous work demonstrated that heteroatom substitution within the Keggin-type polycation ε-Al13 to form ε-GaAl12 and ε-GeAl12 can enhance removal of bacteria, DOC, and turbidity from wastewater. Additional hydrolysis of the ε-Al13 species to form larger Al30 species has also been shown to improve coagulation, but this aspect has not been evaluated for the ε-GaAl12 and ε-GeAl12 systems. In the current study, hydrolysis of ε-Al13, ε-GaAl12 and ε-GeAl12 was promoted through hydrothermal aging to evaluate the overall solution stability/behavior and water treatment efficiency. Turbidity measurement of aged solution indicated that Ga substituted aluminum-oxo Keggin polycations remain stable in solution and DLS studies demonstrated greater diversity in particle sizes within the system. Additional thermogravimetric analyses of metal hydroxide precipitates formed from the aging studies indicate that the GaAl12 system behaves more like an amorphous Al(OH)3 phase, which has higher solubility than other aluminum hydroxide phases. Hydrothermal aging did not significantly change %DOC removal as all solution showed high efficiency for removal across a range of pH values. GaAl12 solutions demonstrated good turbidity removal efficiency in all pH range, with enhanced performance at pH 5. The study suggests that larger, relatively stable oligomers do exist within the aged GaAl12 solutions that may contribute to enhanced contaminant removal in a similar manner to what is observed within the PACl-Al30 coagulant.

Effect of pH and Temperature on Coagulation Efficiency in a North-China Water Treatment Plant

2011 ◽  
Vol 243-249 ◽  
pp. 4835-4838 ◽  
Author(s):  
Di Guan ◽  
Zhen Zhang ◽  
Xing Li ◽  
Hui Liu
Keyword(s):  
Water Treatment ◽  
North China ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Optimum Dose ◽  
Organic Loading ◽  
Experimental Conditions ◽  
Turbidity Removal ◽  
Polyaluminum Chloride ◽  
Ph Range

This research focused on the effect of water temperature and pH to coagulation efficiencies in low turbidity water. And the optimum dose of coagulant was determined. Simulated the treatment processing, the organic matters and turbidity removal capacities of polyaluminum chloride (PACl) were measured in parameters of turbidity, CODMn and UV254 with different experimental conditions. The results indicated that the PACl optimum doses were 28mg/L. By increasing water temperatures in the range of 4°C～18°C, the turbidity removal efficiency was gradually enhanced, while the organic loading removal performed few correlations to temperatures. And the effective pH range was 6.0~9.0, that appeared greater influence on turbidity removal than organic loadings.

scholarly journals APLIKASI KOAGULAN ALAMI DARI TEPUNG JAGUNG DALAM PENGOLAHAN AIR BERSIH

2013 ◽  
Vol 2 (2) ◽  
Author(s):  
Eka Prihatinningtyas
Keyword(s):  
Water Treatment ◽  
Optimum Condition ◽  
Suspended Solids ◽  
High Efficiency ◽  
Settling Velocity ◽  
Maize Yield ◽  
Active Components ◽  
Turbidity Removal ◽  
Natural Coagulant ◽  
Solids Removal

Maize can be used as natural coagulant in water treatment process.The aim of this research was find the optimum condition on water treatment using natural coagulant from maize. Maize extract made by dissolving 5 grams of maize into 100 ml NaCl. The solution separated by centrifugation. The supernatant named extract of maize. Extract of maize loaded onto column packed with Amberlite and produced ionic maize.The active components are carboxyl, hydroxyl and amides groups. Ionic maize yield better turbidity removal than extract of maize. Coagulation withh high initial turbidity gave high efficiency of turbidity removal than low turbidity. Coagulation process runs efficiently at pH 5 because at that point the isoelectric point was obtained. The flowrate less than 0.03 m/ min, the alum will provide the efficiency of suspended solids removal greater than extract of maize. While the over flowrate higher than 0.03 m / min, settling velocity of kaolin using alum and extract of maize are the same.

scholarly journals Recent Advances of Photocatalytic Application in Water Treatment: A Review

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1804
Author(s):  
Guangmin Ren ◽  
Hongtao Han ◽  
Yixuan Wang ◽  
Sitong Liu ◽  
Jianyong Zhao ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Water Treatment ◽  
High Efficiency ◽  
Low Cost ◽  
Great Promise ◽  
Rapid Progress ◽  
Recent Advances ◽  
Photocatalytic Application ◽  
Oxidation Technology ◽  
Performance Challenges

Photocatalysis holds great promise as an efficient and sustainable oxidation technology for application in wastewater treatment. Rapid progress developing novel materials has propelled photocatalysis to the forefront of sustainable wastewater treatments. This review presents the latest progress on applications of photocatalytic wastewater treatment. Our focus is on strategies for improving performance. Challenges and outlooks in this promising field are also discussed. We hope this review will help researchers design low-cost and high-efficiency photocatalysts for water treatment.

Schiff base equilibria. II. Beryllium complexes of N-n-butylsalicylideneimine and the hydrolysis of the Be2+ ion

1965 ◽  
Vol 18 (5) ◽  
pp. 651 ◽  
Author(s):  
RW Green ◽  
PW Alexander
Keyword(s):  
Aqueous Solution ◽  
Schiff Base ◽  
Complex Formation ◽  
Distribution Coefficient ◽  
Dilute Aqueous Solution ◽  
The Stability ◽  
Ph Range ◽  
Hydrolysis Of ◽  
Beryllium Complexes ◽  
Equilibria In Aqueous Solution

The Schiff base, N-n-butylsalicylideneimine, extracts more than 99.8% beryllium into toluene from dilute aqueous solution. The distribution of beryllium has been studied in the pH range 5-13 and is discussed in terms of the several complex equilibria in aqueous solution. The stability constants of the complexes formed between beryllium and the Schiff base are log β1 11.1 and log β2 20.4, and the distribution coefficient of the bis complex is 550. Over most of the pH range, hydrolysis of the Be2+ ion competes with complex formation and provides a means of measuring the hydrolysis constants. They are for the reactions: Be(H2O)42+ ↔ 2H+ + Be(H2O)2(OH)2, log*β2 - 13.65; Be(H2O)42+ ↔ 3H+ + Be(H2O)(OH)3-, log*β3 -24.11.

scholarly journals Evaluation of an environmentally sustainable UV-assisted water treatment system for the removal of Bacillus globigii spores in water

2017 ◽  
Vol 18 (3) ◽  
pp. 968-975
Author(s):  
R. G. Silva ◽  
J. Szabo ◽  
V. Namboodiri ◽  
E. R. Krishnan ◽  
J. Rodriguez ◽  
...  
Keyword(s):  
Water Treatment ◽  
High Efficiency ◽  
Membrane Filter ◽  
Water Security ◽  
Disinfection Byproducts ◽  
Treatment System ◽  
Health Concern ◽  
Environmentally Sustainable ◽  
Inorganic Substances ◽  
The Impact

Abstract Development of greener water treatment technologies is important for the production of safe drinking water and water security applications, such as decontamination. Chlorine assisted disinfection is common and economical, but can generate disinfection byproducts (DBPs) that may be of health concern. DBPs are formed due to the reaction of chlorine with naturally occurring organic and inorganic substances in water. Currently, various innovative technologies are being developed as alternative approaches for preventing DBPs during water treatment. In this study, we evaluated the effectiveness of a novel combination of high efficiency flow filtration and UV disinfection treatment system for the removal of Bacillus globigii (B. globigii) spores in water. The filtration system consists of a charged membrane filter (CMF) that not only helps to remove suspended particles but also reduces the impact of other impurities including bio organisms. In order to get most performance details, the CMF was evaluated at clean, half-life, and end of life (EOL) conditions along with 100% UV transmittance (UVT). In addition, the effectiveness of the UV system was evaluated as a stand alone system at 100% and 70% EOL intensity. The study was conducted at the US EPA's Test and Evaluation (T&E) Facility in Cincinnati, OH, using B. globigii, a surrogate for B. anthracis spores. This non-chemical environmentally-friendly CMF/UV combination system and the stand alone UV unit showed greater than 6.0 log removal of B. globigii during the tests.

Rehabilitation of water treatment plants with operational constrains: a study on turbidity removal

2013 ◽  
Vol 3 (4) ◽  
pp. 549-556 ◽  
Author(s):  
Kaveh Sookhak Lari ◽  
Morteza Kargar
Keyword(s):  
Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Term Effect ◽  
High Rate ◽  
Water Turbidity ◽  
Turbidity Removal ◽  
Water Treatment Plants ◽  
Long Term Effect

High-rate lamella settlers in clarifiers and triple media filters have been implemented in Isfahan water treatment plant (known as ‘Baba-Sheikh-Ali’) in Iran to upgrade existing clarification/filtration processes during the recent years. The applied technologies are mainly used to reduce finished water turbidity as the primary regional criterion on water quality. However, application of both technologies faced some operational limitations since they began to work. These problems are due to the existing layout of the process units and available materials. The current study focuses on performance of restricted application of the two technologies with respect to turbidity removal. Online measured turbidity data from a two-year field observation (since March 2010) are used. In particular, results show a more promising and long-term effect on turbidity removal due to tripling filter media rather than application of the lamella settlers in clarifiers. The reasons for these observations are discussed.

Micellar catalysis of organic reactions. VIII. Kinetic studies of the hydrolysis of 2-acetyloxybenzoic acid (aspirin) in the presence of micelles

1982 ◽  
Vol 35 (7) ◽  
pp. 1357 ◽  
Author(s):  
TJ Broxton
Keyword(s):  
Aqueous Solution ◽  
Cetyltrimethylammonium Bromide ◽  
Cetylpyridinium Chloride ◽  
Kinetic Studies ◽  
Base Catalysis ◽  
Plateau Region ◽  
General Base ◽  
Mechanism Of Hydrolysis ◽  
Ph Range ◽  
Hydrolysis Of

The hydrolysis of 2-acetyloxybenzoic acid in the pH range 6-12 has been studied in the presence of micelles of cetyltrimethylammonium bromide (ctab) and cetylpyridinium chloride (cpc). In the plateau region (pH 6-8) the hydrolysis is inhibited by the presence of micelles, while in the region where the normal BAC2 hydrolysis (pH > 9) occurs the reaction is catalysed by micelles of ctab and cpc. The mechanism of hydrolysis in the plateau region is shown to involve general base catalysis by the adjacent ionized carboxy group both in the presence and absence of micelles. This reaction is inhibited in the presence of micelles because the substrate molecules are solubilized into the micelle and water is less available in this environment than in normal aqueous solution.

scholarly journals Use of Aloe vera as an Organic Coagulant for Improving Drinking Water Quality

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2024
Author(s):  
Abderrezzaq Benalia ◽  
Kerroum Derbal ◽  
Amel Khalfaoui ◽  
Raouf Bouchareb ◽  
Antonio Panico ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Suspended Solids ◽  
Aluminum Sulfate ◽  
Aloe Vera ◽  
Drinking Water Treatment ◽  
Water Turbidity ◽  
Turbidity Removal ◽  
Maximum Turbidity ◽  
Optimal Ph

The coagulation–flocculation–sedimentation process is widely used for removal of suspended solids and water turbidity reduction. The most common coagulants used to conduct this process are aluminum sulfate and ferric sulfate. In this paper, the use of Aloe vera as a natural-based coagulant for drinking water treatment was tested. The bio-coagulant was used in two different forms: powder as well as liquid; the latter was extracted with distilled water used as a solvent. The obtained results showed that the use of the natural coagulant (Aloe vera) in both powder (AV-Powder) and liquid (AV-H2O) forms reduced the water turbidity at natural pH by 28.23% and 87.84%, respectively. Moreover, it was found that the use of the two previous forms of bio-coagulant for drinking water treatment had no significant influence on the following three parameters: pH, alkalinity, and hardness. The study of the effect of pH on the process performance using Aloe vera as a bio-coagulant demonstrated that the maximum turbidity removal efficiency accounted for 53.53% and 88.23% using AV-Powder and AV-H2O, respectively, at optimal pH 6.

Polyoxometalates as sialidase mimics: selective and non-destructive removal of sialic acid from a glycoprotein promoted by phosphotungstic acid

2017 ◽  
Vol 53 (76) ◽  
pp. 10600-10603 ◽  
Author(s):  
Laura Sofia Van Rompuy ◽  
Tatjana N. Parac-Vogt
Keyword(s):  
Sialic Acid ◽  
Phosphotungstic Acid ◽  
Glycosidic Bond ◽  
Selective Hydrolysis ◽  
Fetuin A ◽  
Keggin Type ◽  
Terminal Sialic Acid ◽  
Non Destructive ◽  
Hydrolysis Of

The selective hydrolysis of the glycosidic bond between the terminal sialic acid and the penultimate sugar has been achieved in the alpha-2-HS-glycoprotein (Fetuin-A) in the presence of H3PW12O40, a Keggin type polyoxometalate.

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