Reactions of chlorine with inorganic and organic compounds during water treatment—Kinetics and mechanisms: A critical review

Water is of fundamental importance for life on earth. The synthesis and structure of cell constituents and transport of nutrients into the cells as well as body metabolism depend on water. The contaminations present in water disturb the spontaneity of the mechanism and result in long/short-term diseases. The probable contaminations and their possible routes are discussed in the present review. Continued research efforts result in some processes/technologies to remove the contaminations from water. The review includes concepts and potentialities of the technologies in a comprehensible form. It also includes some meaningful hybrid technologies and promising awaited technologies in coming years.

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Drinking water contamination and treatment techniques

Mechanisms of phenanthrene desorption from five subsurface materials in supercritical carbon dioxide (SC CO2) were investigated by measuring isotherms in the presence of fixed quantities of a polar cosolvent (methanol) and by calculating desorption enthalpies from the temperature dependence of the isotherms. The addition of 7.4 mol % methanol to the SC CO2 phase resulted in 2−11-fold reductions in Freundlich capacity factors at 120 atm and 50 °C. The capacity reduction greatly exceeded that expected from the 21% increase in phenanthrene solubility accompanying cosolvent addition. Isotherms became more linear at 120 atm and 50 °C upon methanol addition for all sorbents except a shale sample. Solubility and organic carbon-normalized phenanthrene sorption capacities declined with increasing solvent polarity, in the order dry SC CO2 > methanol-amended SC CO2 > aqueous solution, and declined with sorbent organic carbon content. Sorption enthalpies from an ideal gas reference state ranged from −106 to −70 kJ/mo...

A distributed reactivity model for sorption by soils and sediments. 7. Enthalpy and polarity effects on desorption under supercritical fluid conditions

Biological water denitrification—A review

The adsorption of three metal ions, Cu(II), Ni(II), and Pb(II), is performed by activated carbon cloths (ACC). Two adsorbents, CS 1501 (with more than 96% of micropore volume) and RS 1301 (with 32% of mesopore volume), are studied. Batch experiments are carried out to assess kinetic and equilibrium parameters. They allow kinetic data, transfer coefficients, and maximum adsorption capacities to be computed. These parameters show the fast external film transfer of metal ions on fibers, because of their low diameter (10 μm). Intraparticular diffusion coefficients are lower than those obtained with a granular activated carbon, but maximum adsorption capacities agree with literature values for GAC. They show the dependency of adsorption on metal ion size and ACC porosity, the largest cation Pb(II) being more adsorbed by the mesoporous cloth. The pH effect is studied, and pH adsorption edges are determined. They are short, only 2 pH units, and located below the precipitation edges. A decrease of equilibrium pH ...

Removal of Cu(II), Pb(II), and Ni(II) by Adsorption onto Activated Carbon Cloths

Oxidation-reduction potential (ORP) regulation as a way to optimize aeration and C, N, and P removal: experimental basis and various full-scale examples

ORP regulation and activated sludge: 15 years of experience

Pollutant Adsorption onto Activated Carbon Membranes

A procedure allowing an efficient regeneration by Joule effect, of activated carbons (granular or fibrous) used for the purification of hydrocarbon polluted air is proposed. This process was developped on pilot units feed. Optimal operation conditions (electrical power, temperature, air flow rate) were determined. Further, suggestions were made for the recovery of the desorbed solvents and potential applications of the procedure.

Guy Martin

Papers

Oxidation-reduction potential (ORP) regulation as a way to optimize aeration and C, N, and P removal: experimental basis and various full-scale examples

ORP regulation and activated sludge: 15 years of experience

Pollutant Adsorption onto Activated Carbon Membranes

La regeneration par echauffement intrinseque, de charbons actifs utiuses pour le traitement d'air

First approach of desorption energies of water and organic molecules onto activated carbon by differential scanning calorimetry studies