Photodegradation of pentachlorophenol in room temperature ionic liquids

Ionic liquid-based water treatment technologies for organic pollutants: Current status and future prospects of ionic liquid mediated technologies

Water scarcity motivated the scientific researcher to develop efficient technologies for the wastewater treatment for its reuse. Ionic liquids have been applied to many industrial and analytical separation processes, but their applications in the wastewater treatment, especially in the removal of organic pollutants, are still not well explored. Potential applications of ionic liquids include solvent extraction, solvent membrane technologies and ionic liquid-modified materials that are mainly used as adsorbents. Aforementioned technologies have been examined for the abatement of phenol, chloro- and nitrophenols, toluene, bisphenol A, phthalates, pesticides, dyes, and pharmaceuticals etc. Present review enlightens the application of different ionic liquids in wastewater treatment and suggests the versatility of ionic liquids in the development of rapid, effective and selective removal processes for the variety of organic pollutants. Implementation of ionic liquid based technologies for wastewater treatment have lots of challenges including the selection of non-hazardous ionic liquids, technological applications, high testing requirements for individual uses and scaling-up of the entire pollutant removal, disposal, and ionic liquid regeneration process. Toxicity assessment of water soluble ionic liquids (ILs) is the major issue due to the widespread application of ILs and hence more exposure of environment by ILs. The development of effective technologies for the recovery/treatment of wastewater contaminated with ILs is necessary from the environmental point of view. Furthermore, the cost factor is the major challenge associated with ionic liquid-based technologies.

Assembly of silver-oxo complexes based on N-diphenylphosphanylmethyl-3-aminopyridine and their structures, photocatalysis and photocurrent responses

Compound {[Ag(μ-η²-Sal)(3-dppmapy)]}_n exhibits prompt anodic photocurrent responses and high photocatalytic performance in the degradation of organic dyes.

Supported cobalt oxide on graphene oxide: highly efficient catalysts for the removal of Orange II from water

The current paper investigated the removal of the azo dye Orange II from water using advanced oxidation processes based on sulfate radicals. The cobalt oxide catalyst immobilized on graphene oxide (GO) can activate peroxymonosulfate (PMS) for the degradation of Orange II in water. The Co(3)O(4)/GO catalyst system was characterized via X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, and X-ray spectroscopy. Results showed that Co(3)O(4) was distributed on GO. The Co(3)O(4)/GO catalyst system exhibited high activity in Orange II oxidation when the Co(3)O(4)/GO catalyst has an optimum Co(3)O(4) loading. In addition, 100% decomposition could be achieved within 6 min with 0.2mM Orange II, 0.1 g L(-1) catalyst, and 2mM PMS. Meanwhile, inductively coupled plasma analysis revealed that the leach of cobalt ions was low. The catalyst also exhibited stable performance after several rounds of regeneration. Several operational parameters, such as catalyst amount, oxidant amount, pH, temperature, and oxidation rate, affected the degradation of Orange II.

Application of ionic liquids in organic pollutants control

For their unique properties and good solubility for many different materials, ionic liquids (ILs) have been applied in several fields, such as separation process, synthesis, catalysis and electrochemistry. This paper focuses on applications of ILs in organic pollutants control. An overview of separation, recycling and control of organic pollutants with ILs is present, for example, phenolic compounds, polycyclic aromatic hydrocarbon (PAHs) and dyes from wastewater, dioxins from waste gas, polyamides from solid wastes, chlorophenothane (DDT) and dieldrin from contaminated soils. Furthermore, the problems and challenges of ILs in organic pollutants control are discussed.

TiO(2) Photocatalytic Degradation of Phenylarsonic Acid

Phenyl substituted arsenic compounds are widely used as feed additives in the poultry industry and have become a serious environmental concern. We have demonstrated that phenylarsonic acid (PA) is readily degraded by TiO(2) photocatalysis. Application of the Langmuir-Hinshelwood kinetic model for the initial stages of the TiO(2) photocatalysis of PA yields an apparent rate constant (k(r)) of 2.8 µmol/L·min and the pseudo-equilibrium constant (K) for PA is 34 L/mmol. The pH of the solution influences the adsorption and photocatalytic degradation of PA due to the surface charge of TiO(2) photocatalyst and speciation of PA. Phenol, catechol and hydroquinone are observed as the predominant products during the degradation. The roles of reactive oxygen species, •OH, (1)O(2), O(2) (-•) and h(VB) (+) were probed by adding appropriate scavengers to the reaction medium and the results suggest that •OH plays a major role in the degradation of PA. By-products studies indicate the surface of the catalyst plays a key role in the formation of the primary products and the subsequent oxidation pathways leading to the mineralization to inorganic arsenic. TiO(2) photocatalysis results in the rapid destruction of PA and may be attractive for the remediation of a variety of organoarsenic compounds.