Treatment of bleaching Kraft mill effluents and polychlorinated phenolic compounds with ozonation

Abstract

The effect of the simultaneous use of ozone, UVA or visible light, and small quantities of Fe(II)/Fe(III) ions in solution on the degradation rate of the organic content of a bleaching Kraft mill ef¯uent was investigated. The same treatment was applied to synthetic samples of polychlorinated phenolic compounds, because these are one of the main groups of compounds found in real bleaching Kraft mill ef¯uents. In order to improve the treatment ef®ciency and to lower the cost of the process several other strategies were investigated. It was found that a previous irradiation of the wastewater or the synthetic sample in the absence of ozone signi®cantly improves the rate of removal of organic pollutants during the subsequent ozonation step.

Effect of high voltage atmospheric cold plasma on white grape juice quality

“…HVACP treatments with air generate many reactive oxygen species and ozone in the discharge. Phenolic compounds are particularly known to be susceptible to ozone attack through the degradation of aromatic rings in their structure . Similar degradation of phenolic compounds after cold plasma treatments was also reported in lettuce and orange juice .…”

“…Phenolic compounds are particularly known to be susceptible to ozone attack through the degradation of aromatic rings in their structure. 43,44 Similar degradation of phenolic compounds after cold plasma treatments was also reported in lettuce 45 and orange juice. 24 However, it was interesting to note that HVACP treatment significantly increased the total flavonols in grape juice in a time-dependent manner.…”

Color, TOC and AOX removals from pulp mill effluent by advanced oxidation processes: A comparative study

“…Ozone is a strong oxidizing agent with oxidation mechanism either by direct reaction with dissolved compounds or by the generated radicals depending on the pH of the solution [24]. The ozone dosage to be applied to the pulp mill effluent depends on total color and TOC content [25] and also on the presence of toxic metabolites [26].…”

A Review on the Applications of Ozonation for the Treatment of Real Agro-Industrial Wastewaters

“…Models to predict the amount of ozone leaving the reactor were developed and it was concluded that it was possible to run an ozonation system without an off-gas ozone control system (off-gas ozone has to be lower than 1 ppm as legally imposed) by controlling ozone absorption. Einstein/s X TOC = 60-90% (Pérez et al 2002) Pulp and paper wastewater coming from anaerobic Thus, the ozone contactor should be high enough to guarantee gas-liquid contact since most of ozone absorption occurs in the bottom of the column; moreover, operating in countercurrent and increasing mean hydraulic retention time showed to lead to lower off-gas ozone. Similar results were attained by (El-Din and Smith 2001) when analyzed Kraft pulp mill effluents ozonation in an impinging-jet bubble column.…”

“…To enhance TOC removal of a pulp and paper effluent by the O 3 /UV process, Pérez et al (2002) tested the impact of the addition of iron ions (Fe 2+ ), which will act as homogeneous catalyst. The maximum TOC removal was about 90% in 300 min of reaction.…”