Ozonation of nanofiltration permeate of whey before processing by reverse osmosis

During nanofiltration processing of whey a significant amount of permeate is generated. In some cases this permeate is treated by reverse osmosis to get purified water for technological needs. Dry substances are not used, because they contain practically the same amount of organic and inorganic components. Mineral substances can be used for the mineralization of drinking water purified by reverse osmosis. However, the presence of organic compounds complicates the process of separation, as well as reduces the specific productivity of reverse osmosis membranes at the concentration stage. Therefore, the search for methods of destruction and removal of organic components is grounded. In the presented work, experimental studies of ozonation and sorption of organic compounds by activated carbon were carried. It has been shown that ozonation improves the degree of sorption purification by six times. Sequential treatment with ozone and subsequent filtration through the layer of activated carbon improves the specific productivity of reverse osmosis membranes by 30% at the stage of treatment of the nanofiltration permeate, while their selectivity remains unchanged.

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Artificial neural network models based on QSAR for predicting rejection of neutral organic compounds by polyamide nanofiltration and reverse osmosis membranes

Journal of Membrane Science ◽

10.1016/j.memsci.2009.06.048 ◽

2009 ◽

Vol 342 (1-2) ◽

pp. 251-262 ◽

Cited By ~ 55

Author(s):

V. Yangali-Quintanilla ◽

A. Verliefde ◽

T.-U. Kim ◽

A. Sadmani ◽

M. Kennedy ◽

...

Keyword(s):

Neural Network ◽

Artificial Neural Network ◽

Reverse Osmosis ◽

Organic Compounds ◽

Network Models ◽

Neural Network Models ◽

Artificial Neural ◽

Neutral Organic Compounds ◽

Artificial Neural Network Models ◽

Reverse Osmosis Membranes

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Catalytic reduction of nitrate in reverse osmosis concentrate by using Pd-Cu/activated carbon felt

Energy & Environment ◽

10.1177/0958305x20923115 ◽

2020 ◽

pp. 0958305X2092311

Author(s):

Carolina Andrea Bahamondes Fuentes ◽

Yuhoon Hwang

Keyword(s):

Activated Carbon ◽

Reverse Osmosis ◽

Nitrate Reduction ◽

Catalytic Reduction ◽

Reduction Rate ◽

Carbon Felt ◽

High Concentration ◽

Acidic Conditions ◽

Supporting Materials ◽

Inorganic Components

The reverse osmosis concentrate generated during the water reuse process contains a high concentration of nitrate but a low amount of biodegradable organic carbon for heterotrophic denitrification. Catalytic reduction of nitrates using Pd-Cu is one of the most promising technologies to achieve complete removal of nitrate; however, the effect of a range of experimental factors on the nitrate removal rate and N2 selectivity is still an ongoing concern. Two kinds of supporting materials, alumina and activated carbon felt, were used to immobilize the Pd-Cu catalyst. The alumina-based catalyst was used to establish reference conditions for further experiments, and the effect of pH control was evaluated for both supporting materials. It was observed that pH has a direct influence on the nitrate reduction rate as well as the N2 selectivity. Nitrate reduction efficiency was low at acidic conditions while the highest N2 selectivity was obtained at the acidic conditions. The optimal pH condition for Pd-Cu/activated carbon felt was determined as pH 4, showing the highest total nitrogen removal as N2 gas. Finally, the feasibility of catalytic nitrate reduction for reverse osmosis concentrate was evaluated by investigating the effects of organic and inorganic components commonly present in reverse osmosis concentrate. The organic and inorganic components did not show a significant inhibitory effect on catalytic nitrate reduction, while a high concentration of salt significantly decreased the nitrate reduction rate as well as the N2 selectivity. The filter type morphology of the Pd-Cu/activated carbon felt would be beneficial for field application compared to the conventional catalyst with powder form.

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