Degradation Category Rating

The activated sludge process has been found to be the most efficient treatment for various categories of pharmaceutical wastewater [14,15,19,42-46]. It has also been reported that this process can be successfully employed for the removal of tert-butanol, a common solvent in pharmaceutical wastewater that cannot be degraded by anaerobic treatment [44]. At a volumetric loading rate of 1.05 kg COD/m day, HRT (hydraulic retention time) of 17 hours, and mixed liquor dissolved oxygen concentration of 1 mg/dm, the tert-butanol can be completely removed by the activated sludge process. 

It is noteworthy that oxidative reaction rates, whether in solid state or in solution, may not be readily predicted using just thermal stress. For this reason, oxidative degradation is broken out into a separate category (see the section on Oxidative Degradation for more discussion). 

Effect of diffusion on chemical degradation. In principle, diffusion in a polymer matrix will affect the rates of all of the bimolecular reactions to some degree. Four categories of such reactions have been treated. 

Micro- and nanoparticles are an in5)ortant category of delivery systems used in medicine, and the use of PLA is interesting due to its hydrolytic degradability and low toxicity. The most important properties of the micro- and nanoparticles are the drug release rate and the matrix degradation rate which are affected by the particle design and the material properties [7]. Copolymers of GA and rac-lactide [5] seem to be the most suitable combinations for use as drug delivery matrices. 

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