Assessing the application of advanced oxidation processes, and their combination with biological treatment, to effluents from pulp and paper industry

The application of advanced oxidation technologies to the treatment of effluents from the pulp and paper industry: a review

“…Correspondingly, Medeiros et al (2008) also showed higher color and HMW fraction removals and biodegradability increase at pH = 7 than at 12. More recently, Merayo et al (2013) have reported non-significant differences between the ozone treatment of recycled paper mill effluents performed at pH = 7 and 12; and an even higher ozonation efficiency at pH = 7 for kraft pulp mill effluents. Considering all together, working at the typical pH values of neutral-basic pulp and paper mill effluents (pH = 7-9) addressed the great advantage of avoiding pH control mechanisms (Kreetachat et al 2007;Oeller et al 1997;Salokannel et al 2007).…”

“…Nevertheless, and as it has already been pointed out, ozone consumption rate will decrease during ozonation due to the progressive reaction with organic matter, so this decrease depends on the nature of the compounds present in the solution; that is, proportional to the amount of easily oxidized compounds (Fontanier et al 2005b;Salokannel et al 2007;Merayo et al 2013). Finally, Bierbaum and Oeller (2009) implemented on-line control systems for the continuous ozonation treatment of biologically treated effluents from recycled paper mills, showing that a controlled ozone production is useful and necessary, ensuring the stable operation of subsequent stages.…”

“…Considering all together, working at the typical pH values of neutral-basic pulp and paper mill effluents (pH = 7-9) addressed the great advantage of avoiding pH control mechanisms (Kreetachat et al 2007;Oeller et al 1997;Salokannel et al 2007). Nevertheless, slight pH variations may occur during the oxidation reaction due to the formation of small acid by-products (Balcioglu et al 2007;Merayo et al 2013) or the generation of carbonate along the mineralization process (Oeller et al 1997). …”

“…The pH is not usually as strongly basic as for a kraft process, and more starch-related products (rather than lignin ones) can be found (Amat et al 2005a), resulting that these effluents are more biodegradable (Merayo et al 2013;Thompson et al 2001). In addition, it is also important to consider that the papermaking operation with recycled fibers may introduce different chemical compounds in the effluent, such as EDTA, which is very difficult to degrade by biological technologies (Sundholm 1999).…”

“…Whereas the combination of biological treatments (anaerobic and aerobic) achieved about an 80% removal of different phtalates, photoFenton treatment achieved a 100% removal. In general, AOPs can be applied to industrial wastewater as a polishing step integrated with conventional chemical and/or biological processes in order to increase the overall treatment effectiveness (Alvares et al 2001;Balcioglu et al 2003;Legrini et al 1993;Merayo et al 2013;Oeller et al 1997;Tanaka and Ichikawa 1993).…”