in order to prevent water losses through disposing hydrous sludge during treatment of water, also recovery and reuse of chemicals; treatment by magnesium carbonate as a coagulant was examined in batch and continuous systems. 600 mg/1 mgco3 as optimum dosage reduced 80% turbidity of a highly turbid water containing 200 ntu. sulfates decreased, but hardness and alkalinity showed some increases. r...

Reducing carbon dioxide with a multicomponent artificial photosynthetic system, closely mimicking nature, represents a promising approach for energy storage. Previous works have focused on exploiting light-harvesting semiconductor nanowires (NW) for photoelectrochemical water splitting. With the newly developed CO2 reduction nanoparticle (NP) catalysts, direct interfacing of these nanocatalysts...

This review summarizes research on the electrochemical and photochemical reduction of CO2 using a variety of iron and cobalt porphyrins, phthalocyanines, and related complexes. Metalloporphyrins and metallophthalocyanines are visible light absorbers with extremely large extinction coefficients. However, yields of photochemically-generated active catalysts for CO2 reduction are typically low owi...

We report a novel system of visible-light-driven CO2 reduction to CO in an aqueous solution, in which DPPC vesicles dispersed in the solution act as a photocatalyst using ascorbate (HAsc(-)) as an electron source. In the vesicles metal complexes [Ru(dtb)(bpy)2](2+) and Re(dtb)(CO)3Cl (dtb = 4,4'-ditridecyl-2,2'-bipyridyl) are incorporated, which act as a photosensitizer and a catalyst for CO2 r...

Selective catalytic reduction of NOx with NH3 (NH3-SCR) has been widely investigated to reduce NOx emissions from combustion processes, which cause environmental challenges. However, most of the current work on NOx reduction has focused on using feed gas without CO2 or containing small amounts of CO2. In the future, oxy-fuel combustion will play an important role for power generation, and this ...

We report here the efficient reduction of CO2 to CO by cobalt aminopyridine macrocycles. The effect of the pendant amines on catalysis was investigated. Several cobalt complexes based on the azacalix[4](2,6)pyridine framework with different substitutions on the pendant amine groups have been synthesized (R = H (1), Me (2), and allyl (3)), and their electrocatalytic properties were explored. Und...

A bifunctionalized TiO2 film containing a dye-sensitized zone and a catalysis zone is designed for visible-light photocatalytic reduction of CO2 to chemicals continuously. Charge separation can be accomplished with electron transferring to catalysis zone and positive charge transforming to anode. Highly efficient conversion of CO2 to formic acid, formaldehyde, and methanol is achieved through t...

A series of nickel complexes featuring redox-active macrocycles is reported for electrocatalytic CO2 reduction. A remarkable structure-activity relationship is elucidated from the series through electrochemical studies and DFT calculations, wherein a fine electronic balance between metal and ligand redox chemistry dictates selectivity for CO2 reduction versus the competing proton reduction reac...

A new mononuclear ruthenium(ii) complex, trans-[Ru(dmb)2(Cl)(EtOH)](PF6) (dmb = 4,4'-dimethyl-2,2'-bipyridine), has been prepared and characterized by elemental analysis, spectroscopic techniques and single crystal X-ray structure determination. The complex was studied as a precatalyst for the electrocatalytic reduction of CO2 to CO in an acetonitrile solution by cyclic voltammetry (CV). The ca...