A quantitative speciation model for the adsorption of organic pollutants on activated carbon

2013 ◽  
Vol 68 (6) ◽  
pp. 1370-1376 ◽  
Author(s):  
M. Grivé ◽  
D. García ◽  
C. Domènech ◽  
L. Richard ◽  
I. Rojo ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Organic Pollutants ◽  
Current Knowledge ◽  
Quantitative Description ◽  
High Capacity ◽  
Chemical Properties ◽  
Quantitative Model ◽  
Surface Groups ◽  
Potentiometric Titrations ◽  
Chemical Groups

Granular activated carbon (GAC) is commonly used as adsorbent in water treatment plants given its high capacity for retaining organic pollutants in aqueous phase. The current knowledge on GAC behaviour is essentially empirical, and no quantitative description of the chemical relationships between GAC surface groups and pollutants has been proposed. In this paper, we describe a quantitative model for the adsorption of atrazine onto GAC surface. The model is based on results of potentiometric titrations and three types of adsorption experiments which have been carried out in order to determine the nature and distribution of the functional groups on the GAC surface, and evaluate the adsorption characteristics of GAC towards atrazine. Potentiometric titrations have indicated the existence of at least two different families of chemical groups on the GAC surface, including phenolic- and benzoic-type surface groups. Adsorption experiments with atrazine have been satisfactorily modelled with the geochemical code PhreeqC, assuming that atrazine is sorbed onto the GAC surface in equilibrium (log Ks = 5.1 ± 0.5). Independent thermodynamic calculations suggest a possible adsorption of atrazine on a benzoic derivative. The present work opens a new approach for improving the adsorption capabilities of GAC towards organic pollutants by modifying its chemical properties.

Resorcinarene Cavitand Polymers for the Remediation of Halomethanes and 1,4-Dioxane

2019 ◽  
Author(s):  
Luke Skala ◽  
Anna Yang ◽  
Max Justin Klemes ◽  
Leilei Xiao ◽  
William Dichtel
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
High Capacity ◽  
The United States ◽  
Water Sources ◽  
Disinfection Byproducts ◽  
Porous Polymer ◽  
Organic Micropollutants ◽  
Executive Summary ◽  
Regulatory Limits

<p>Executive summary: Porous resorcinarene-containing polymers are used to remove halomethane disinfection byproducts and 1,4-dioxane from water.<br></p><p><br></p><p>Disinfection byproducts such as trihalomethanes are some of the most common micropollutants found in drinking water. Trihalomethanes are formed upon chlorination of natural organic matter (NOM) found in many drinking water sources. Municipalities that produce drinking water from surface water sources struggle to remain below regulatory limits for CHCl<sub>3</sub> and other trihalomethanes (80 mg L<sup>–1</sup> in the United States). Inspired by molecular CHCl<sub>3</sub>⊂cavitand host-guest complexes, we designed a porous polymer comprised of resorcinarene receptors. These materials show higher affinity for halomethanes than a specialty activated carbon used for trihalomethane removal. The cavitand polymers show similar removal kinetics as activated carbon and have high capacity (49 mg g<sup>–1</sup> of CHCl<sub>3</sub>). Furthermore, these materials maintain their performance in real drinking water and can be thermally regenerated under mild conditions. Cavitand polymers also outperform activated carbon in their adsorption of 1,4-dioxane, which is difficult to remove and contaminates many public water sources. These materials show promise for removing toxic organic micropollutants and further demonstrate the value of using supramolecular chemistry to design novel absorbents for water purification.<br></p>

scholarly journals Fate of hydrocarbon pollutants in source and non-source control sustainable drainage systems

2013 ◽  
Vol 69 (4) ◽  
pp. 703-709 ◽  
Author(s):  
Georgios Roinas ◽  
Cath Mant ◽  
John B. Williams
Keyword(s):  
Organic Pollutants ◽  
Chemical Properties ◽  
Pollutant Removal ◽  
Total Petroleum Hydrocarbons ◽  
Source Control ◽  
Storm Events ◽  
Pollutant Loads ◽  
Significant Difference ◽  
Local Roads ◽  
Polycyclic Aromatic

Sustainable drainage (SuDs) is an established method for managing runoff from developments, and source control is part of accepted design philosophy. However, there are limited studies into the contribution source control makes to pollutant removal, especially for roads. This study examines organic pollutants, total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAHs), in paired source and non-source control full-scale SuDs systems. Sites were selected to cover local roads, trunk roads and housing developments, with a range of SuDs, including porous asphalt, swales, detention basins and ponds. Soil and water samples were taken bi-monthly over 12 months to assess pollutant loads. Results show first flush patterns in storm events for solids, but not for TPH. The patterns of removal for specific PAHs were also different, reflecting varying physico-chemical properties. The potential of trunk roads for pollution was illustrated by peak runoff for TPH of &gt; 17,000 μg/l. Overall there was no significant difference between pollutant loads from source and non-source control systems, but the dynamic nature of runoff means that longer-term data are required. The outcomes of this project will increase understanding of organic pollutants behaviour in SuDs. This will provide design guidance about the most appropriate systems for treating these pollutants.

Recent trends in carbon nanotubes based prostate cancer therapy: A biomedical hybrid for diagnosis and treatment

2021 ◽  
Vol 18 ◽  
Author(s):  
Raja Murugesan ◽  
Sureshkumar Raman
Keyword(s):  
Prostate Cancer ◽  
Carbon Nanotubes ◽  
Drug Delivery ◽  
Drug Loading ◽  
High Surface ◽  
High Surface Area ◽  
High Capacity ◽  
Chemical Properties ◽  
Diagnosis And Treatment ◽  
High Level

: At present treatment methods for cancer are limited, partially due to the solubility, poor cellular distribution of drug molecules and, the incapability of drugs to annoy the cellular barriers. Carbon nanotubes (CNTs) generally have excellent physio-chemical properties, which include high-level penetration into the cell membrane, high surface area and high capacity of drug loading by in circulating modification with bio-molecules, project them as an appropriate candidate to diagnose and deliver drugs to prostate cancer (PCa). Additionally, the chemically modified CNTs which have excellent 'Biosensing' properties therefore makes it easy for detecting PCa without fluorescent agent and thus targets the particular site of PCa and also, Drug delivery can accomplish a high efficacy, enhanced permeability with less toxic effects. While CNTs have been mainly engaged in cancer treatment, a few studies are focussed on the diagnosis and treatment of PCa. Here, we detailly reviewed the current progress of the CNTs based diagnosis and targeted drug delivery system for managing and curing PCa.

scholarly journals The mutagenic and some physico-chemical properties of organic residues obtained from drinking water by Amberlite XAD-2 and activated carbon extraction.

Eisei kagaku ◽  
1988 ◽  
Vol 34 (5) ◽  
pp. 389-400 ◽  
Author(s):  
SUKEO ONODERA ◽  
KEIICHIRO YOSHIMATSU ◽  
SEIGO NAKANO ◽  
HISAYO SAITOH ◽  
SHIZUO SUZUKI
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Chemical Properties ◽  
Organic Residues ◽  
Physico Chemical

scholarly journals Kandungan Antioksidan Teh Hijau Daun Mangrove dan Uji Efektifitasnya Sebagai Antikolesterol Pada Mencit

2018 ◽  
Vol 5 (2) ◽  
pp. 60
Author(s):  
Analuddin Analuddin ◽  
Andi Septiana ◽  
Wa Ode Harlis
Keyword(s):  
Green Tea ◽  
Antioxidant Properties ◽  
High Capacity ◽  
Chemical Properties ◽  
The Other ◽  
Bruguiera Gymnorrhiza ◽  
Rhizophora Stylosa ◽  
Ceriops Tagal ◽  
Ceriops Decandra ◽  
Lumnitzera Racemosa

ABSTRAKPenelitian ini bertujuan untuk menentukan senyawa antioksidan teh hijau dan menjelaskan efektifitas teh hijau daun mangrove sebagai anticholesterol pada mencit. Senyawa kimia bahan antioksidaan teh hijau pada daun mangrove Bruguiera gymnorrhiza, B. parviflora, Rhizophora stylosa, R. mucronata, Lumnitzera racemosa, Ceriops tagal dan C. decandra dianalisis dengan GCMS, sedangkan khasiat teh hijau daun mangroves sebagai antikolesterol di ujikan pada mencit. Hasil penelitian menunjukan bahwa senyawa bahan teh hijau bervariasi diantara daun mangrove yaitu polifenol sederhana ditemukan pada daun semua jenis mangrove yang menjadi sampel penelitian dengan konsentrasi yang bervariasi. Senyawa katekin hanya ditemukan pada daun mangrove Ceriops decandra, L. racemosa, R. mucronata dan R. apiculata. Di sisi lain, flavonoid terdeteksi hanya pada daun C. tagal, B. gymnorrhiza dan R. stylosa, sedangkan senyawa T-flavin hanya ditemukan pada daun B. parviflora. Teh hijau daun mangrove mampu menurunkan kadar kolesterol mencit dengan kisaran 33,33 sampai 53,67% mengindikasikan besarnya potensi daun mangrove sebagai bahan  teh hijau antikolesterol.Kata kunci: bahan teh hijau, polifenol sederhana, katekin, flavonoid, antikolesterol, daun mangroveABSTRACTThis study aimed to determine the antioxidant properties of green tea material in mangrove leaves and elucidate their capacity on reducing the cholesterol of mice. The chemical properties in  leaves of Bruguiera gymnorrhiza, B. parviflora, Rhizophora stylosa, R. mucronata, Lumnitzera racemosa, Ceriops tagal and C. decandra were analyzed by GCMS, while their capability as anticholesterol of mice were examined. The results showed that simple polyphenols were found in all sampled mangrove leaves with different concentration, while the chatechine was found only in leaves of four mangroves including Ceriops decandra, L. racemosa, R. mucronata and R. apiculata. On the other hand, flavonoids was detected only in leaves of C. tagal,  B. gymnorrhiza and R. stylosa. Meanwhile, T-flavine was detected only in leaves of B. parviflora. However, green tea material for all of sampled mangroves showed high capacity to reduce cholesterol of mice that ranging from 33.33% to 53.67%, which indicated high potentitiality of mangroves leaves as green tea material of anticholesterol.Keywords: Green tea material, simple polyphenol, cathechin, flavonoid, anticholesterol, Mangroves leaves

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