Sequential Treatment by Ozonation and Biodegradation of Pulp and Paper Industry Wastewater to Eliminate Organic Contaminants.

In this research, the decomposition of toxic organics from pulp and paper mill effluent by the sequential application of ozonation and biodegradation was studied. Ozonation, as a pre-treatment, was executed to transform the initial pollutants into less toxic compounds (such as organic acids of low molecular weights). Biodegradation was executed during three days with acclimated microorganisms that were able to complete the decomposition of the initial organic mixture (raw wastewater) and to achieve a higher degree of mineralization (85-90%).

Efficient catalytic activity of NiO and CeO films in benzoic acid removal using ozone.

This research focuses on the synthesis of NiO and CeO thin films using spray pyrolysis for the removal of benzoic acid using ozone as an oxidant. The results indicate that the addition of CeO films significantly enhances the mineralization of benzoic acid, achieving a rate of over 80% as the CeO films react with ozone to produce strong oxidant species, such as hydroxyl radicals, superoxide radicals, and singlet oxygen as demonstrated by the presence of quenchers in the reaction system. The difference in catalytic activity between NiO and CeO films was analyzed XPS technique; specifically, hydroxyl oxygen groups in the CeO film were greater in number than those in the NiO film, thus benefitting catalytic oxidation as these species are considered active oxidation sites.

Adaptive modeling of nonnegative environmental systems based on projectional Differential Neural Networks observer.

A new design of a non-parametric adaptive approximate model based on Differential Neural Networks (DNNs) applied for a class of non-negative environmental systems with an uncertain mathematical model is the primary outcome of this study. The approximate model uses an extended state formulation that gathers the dynamics of the DNN and a state projector (pDNN). Implementing a non-differentiable projection operator ensures the positiveness of the identifier states.

Catalytic effect of γ-Al(OH), α-FeOOH, and α-FeO on the ozonation-based decomposition of diethyl phthalate adsorbed on sand and soil.

Diethyl phthalate (DEP) is a pollutant which can be found on soils as a result of its widespread application in plastic industry. Soil contaminated with DEP requires the application of different chemical methods to attain its remediation. Among these methods, ozonation has proven to be effective against toxic soil pollutants.

Effect of the type of soil on dimethyl phthalate degradation by ozone.

In the present study, ozone was applied for the removal of dimethyl phthalate (DMP) from soil. The effect of several experimental parameters was investigated considering, the initial DMP concentration, ozone flow, the type of soil (sand and agricultural soil) and the presence of α-FeOOH as a potential catalyst in the reaction system with sand. The elimination of DMP using ozone is significantly affected by the type of soil.