Bentonite bleaching earth is utilized for purifying used motor oil through a recovery process in order to improve the quality and stability of the final product. Indeed, spent bleaching earth is generated due to adsorbing oil impurities. Polluted spent bleaching earth contains 20-40% (w/w) oil and is flammable. Its disposal without pre-treatment leads to loss of oil along with environmental imp...

A study was carried out on totally chlorine-free (TCF) bleachability of dimethyl formamide (DMF) treated bagasse pulps exposed to CZ-3 and FP 90031-sp strains of white-rot fungus Ceriporiopsis subvermispora. This process involved an oxygen and peroxide stage bleaching sequence. The effect of enzymatic stage on bleachability properties was studied and compared with control pulps, processed witho...

Coral bleaching is a major concern to researchers, conservations and the general public worldwide. To date, much of the high profile attention for bleaching has coincided with major environmental impacts and for many the term coral bleaching is synonymously associated with coral mortality (so-called “lethal” bleaching episodes). Whilst this synonymous association has undoubtedly been key in rai...

The application of bleaching agents before placement of resin-bonded fixed appliances significantly, but temporarily, reduces bond strength to tooth structure. Antioxidants have been studied as a means to remove residual oxygen that compromises bonding to bleached enamel. This in vitro study evaluated whether green tea (GT) could restore the shear bond strength between bonded orthodontic bracke...

OBJECTIVE We evaluated the effects of internal bleaching on the adhesion of glass-fiber posts (GFPs) luted with different resin cements. METHODS Forty extracted human single-root teeth were endodontically treated and divided into four groups (n=10): G1- conventional resin cement (CRC); G2- self-adhesive resin cement (SARC); G3- bleaching + CRC; and G4- bleaching + SARC. Specimens were section...

Tooth bleaching has become a popular cosmetic treatment among patients that want to enhance their esthetic appearance. In addition, light-activated bleaching gels have been growing among dental professionals mainly due to the fastening of the whitening procedure and/or therapeutic purposes. Thus, the objective of this case report was to present the bleaching protocol and efficacy of a light-act...

Cnidarian bleaching results from the breakdown in the symbiosis between the host cnidarian and its dinoflagellate symbiont. Coral bleaching in recent years has increasingly caused degradation and mortality of coral reefs on a global scale. Although much is understood about the environmental causes of bleaching, the underlying cellular mechanisms of symbiont release that drive the process are ju...

The removal of transition metal ions is crucial for improving the efficiency of subsequent peroxide bleaching. Acid-washing and chelation have been proposed for such a purpose. However, their influences on the Mg(OH)2-based peroxide bleaching of hardwood pulps at a high consistency have not been well documented in the literature. In this work, we studied the influence of acid-washing using sulf...

The objective of this study was to investigate if a prolonged bleaching effect of carbamide peroxide-loaded hollow calcium phosphate spheres (HCPS) can be achieved. HCPS was synthesized via a hydrothermal reaction method. Carbamide peroxide (CP) was-loaded into HCPS by mixing with distilled water as solvent. We developed two bleaching gels containing CP-loaded HCPS: one gel with low HP concentr...

Exposure of an intact vertebrate eye to light bleaches the rhodopsin in the photoreceptor outer segments in spatially nonuniform patterns. Some axial bleaching patterns produced in toad rods were determined using microspectrophotometric techniques. More rhodopsin was bleached at the base of the outer segment than at the distal tip. The shape of the bleaching gradient varied with the extent of b...