Evaluation of adsorbability of pesticides in water on powdered activated carbon using octanol-water partition coefficient

1997 ◽  
Vol 35 (7) ◽  
Keyword(s):  
Activated Carbon ◽  
Partition Coefficient ◽  
Powdered Activated Carbon ◽  
Water Partition Coefficient ◽  
Pesticides In Water

Evaluation of adsorbability of pesticides in water on powdered activated carbon using octanol-water partition coefficient

1997 ◽  
Vol 35 (7) ◽  
pp. 219-226 ◽  
Author(s):  
Jian-ying Hu ◽  
Takako Aizawa ◽  
Yasumoto Magara
Keyword(s):  
Activated Carbon ◽  
Adsorption Isotherm ◽  
Partition Coefficient ◽  
Partition Coefficients ◽  
Powdered Activated Carbon ◽  
Adsorption Parameters ◽  
Pesticide Concentration ◽  
Water Partition Coefficient ◽  
Pesticides In Water ◽  
High Polarity

The 1-octanol-water partition coefficients (logPow) of seven pesticides, i.e., Hymexazol, methomyl, imidacloprid, thiophanatemethyl, carbaryl, linuron, thiobencarb, were determined by RPHPLC method. The relation between these estimated logPow and adsorption isotherm parameters on powdered activated carbon was studied by correlating their logPow values with the Freundlich adsorption parameters. The adsorption parameter, logk, was found to increase with the increase of logPow for the pesticides examined. The activated carbon amount needed for lowering pesticide concentration from 500 μg/l to 50 μg/l was calculated. The amount of activated carbon needed for hymexazol (logPow, 0.11) was 688.5 mg/l, while that for thiobencarb (logPow, 3.78) was 5.1 mg/l, which suggests that pesticides with a high polarity, i.e., a low Pow, are difficult to remove by powdered activated carbon.

Adsorptive characteristics of ionogenic aromatic pesticides in water on powdered activated carbon

1998 ◽  
Vol 32 (9) ◽  
pp. 2593-2600 ◽  
Author(s):  
Jian-ying Hu ◽  
Takako Aizawa ◽  
Yutaka Ookubo ◽  
Takeshi Morita ◽  
Yasumoto Magara
Keyword(s):  
Activated Carbon ◽  
Powdered Activated Carbon ◽  
Pesticides In Water

Effect of operational modes on the removal of a synthetic organic chemical by powdered activated carbon during ultrafiltration

2001 ◽  
Vol 1 (5-6) ◽  
pp. 39-47
Author(s):  
Y. Matsui ◽  
A. Yuasa ◽  
F. Colas
Keyword(s):  
Activated Carbon ◽  
Cross Flow ◽  
Powdered Activated Carbon ◽  
Organic Chemical ◽  
Filtration Cycle ◽  
Dead End ◽  
Synthetic Organic Chemical ◽  
The Cross ◽  
Short Time ◽  
Operational Modes

The effects of operational modes on the removal of a synthetic organic chemical (SOC) in natural water by powdered activated carbon (PAC) during ultrafiltration (UF) were studied, through model simulations and experiments. The removal percentage of the trace SOC was independent of its influent concentration for a given PAC dose. The minimum PAC dosage required to achieve a desired effluent concentration could quickly be optimized from the C/C0 plot as a function of the PAC dosage. The cross-flow operation was not advantageous over the dead-end regarding the SOC removal. Added PAC was re-circulated as a suspension in the UF loop for only a short time even under the cross-flow velocity of gt; 1.0 m/s. The cross-flow condition did not contribute much to the suspending of PAC. The pulse PAC addition at the beginning of a filtration cycle resulted in somewhat better SOC removal than the continuous PAC addition. The increased NOM loading on PAC which was dosed in a pulse and stayed longer in the UF loop could possibly further decrease the adsorption rate.

Fate of Toxic Organic Compounds in Activated Sludge and Integrated PAC Systems

1987 ◽  
Vol 19 (3-4) ◽  
pp. 471-482 ◽  
Author(s):  
W. J. Weber ◽  
B. E. Jones ◽  
L. E. Katz
Keyword(s):  
Activated Carbon ◽  
Activated Sludge ◽  
Organic Compounds ◽  
Powdered Activated Carbon ◽  
Carbon Adsorption ◽  
Powdered Carbon ◽  
Benzene Toluene ◽  
Adsorptive Properties ◽  
Carbon Concentrations ◽  
Toxic Organic Compounds

The addition of powdered activated carbon (PAC) to activated sludge treatment systems to enhance removal of specific toxic organic compounds from wastewater was evaluated. Nine organic compounds encompassing a range of solubility, volatility, biodegradability, and adsorptive properties were studied. Kate and equilibrium investigations were conducted to quantify the removal mechanisms of volatilization, biodegradation, biosorption, and carbon adsorption. Results from steady-state bioreactor studies showed that the addition of less than 100 mg/ℓ powdered activated carbon to the influent did not enhance the removal of the biodegradable target compounds investigated: benzene, toluene, ethylbenzene, o-xylene, chlorobenzene, and nitrobenzene. Significantly improved removals of the poorly degradable and non-biodegradable compounds 1,2-dichlorobenzene, 1,2,4-trichlorobenzene, and lindane occurred at influent powdered carbon concentrations in the 12.5 to 25 mg/ℓ range. Influent powdered carbon concentrations of 100 mg/ℓ effected overall removals of greater than 90%. The addition of powdered activated carbon not only reduced effluent concentrations but also reduced the amounts of the volatile compounds stripped to the atmosphere.

scholarly journals QSPR modelling of the octanol/water partition coefficient of organometallic substances by optimal SMILES-based descriptors

2009 ◽  
Vol 7 (4) ◽  
pp. 846-856 ◽  
Author(s):  
Andrey Toropov ◽  
Alla Toropova ◽  
Emilio Benfenati
Keyword(s):  
Partition Coefficient ◽  
Organometallic Compounds ◽  
Applicability Domain ◽  
Training Set ◽  
Input Line ◽  
Test Set ◽  
Water Partition Coefficient ◽  
Definition Of

AbstractUsually, QSPR is not used to model organometallic compounds. We have modeled the octanol/water partition coefficient for organometallic compounds of Na, K, Ca, Cu, Fe, Zn, Ni, As, and Hg by optimal descriptors calculated with simplified molecular input line entry system (SMILES) notations. The best model is characterized by the following statistics: n=54, r2=0.9807, s=0.677, F=2636 (training set); n=26, r2=0.9693, s=0.969, F=759 (test set). Empirical criteria for the definition of the applicability domain for these models are discussed.

scholarly journals Hazardous cyanobacteria integrity response to velocity gradient and powdered activated carbon in water treatment plants

2021 ◽  
Vol 773 ◽  
pp. 145110
Author(s):  
Samylla Oliveira ◽  
Allan Clemente ◽  
Indira Menezes ◽  
Amanda Gois ◽  
Ismael Carloto ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Water Treatment ◽  
Velocity Gradient ◽  
Powdered Activated Carbon ◽  
Water Treatment Plants
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