Aerobic moving bed bioreactor performance: a comparative study of removal efficiencies of kraft mill effluents from Pinus radiata and Eucalyptus globulus as raw material

Abstract

A Moving Bed Bioreactor (MBBR) was operated during 333 days. Two different effluents were fed in six different phases. Phases I and II were fed with effluent where Pinus radiata was used as raw material, while phases III to VI were fed with effluent where Eucalyptus globulus was used as raw material. The HRT was reduced from 85 to 4 h, and the BOD(5):N:P ratio (100:5:1, 100:3:1 and 100:1:1) was also simultaneously evaluated as an operation strategy. When MBBR was operated with Pinus radiata influent, the performance presents a high BOD(5) removal level (above 95%), although COD removal is below 60%. Most of the recalcitrant COD contained in the effluent has a molecular weight higher than 10,000 Da. When MBBR was operated with Eucalyptus globulus influent, the performance is around 97.9-97.6% and 68.6-65.1% for BOD(5) and COD, respectively (with HRT up to 17 h). In the Pinus radiata and Eucalyptus globus effluents, the color was mainly found in the molecular weight fraction up to 10,000 Daltons.

Microbial population in an aerated thermophilic reactor that treats recycled cardboard plant wastewater

“…2). During Phase II, the median efficiency was 84%, which is within the expected values for non-optimized activated sludge treatment of this kind of industrial wastewater [14].…”

Refractory organic pollutants and toxicity in pulp and paper mill wastewaters

“…The biological aerobic treatment is used to remove BOD and COD even though their removal degree typically remains 20-50 % due to highmolecular weight organic compounds (Villamar et al 2009). The influent BOD needs to be high enough (300-700 mg/L) for effective functioning of the aerobic treatment process (Chan et al 2009).…”

Comparison of the chemical precipitation, UV/H2O2 and Fenton processes to optimize removal of chronic toxicity from kraft mill effluents

“…To clarify which pollutant groups are present in STE, the specific compounds were measured by a spectrophotometer in the UV-Vis region. However, some compounds, especially saturated hydrocarbons and carbohydrates, either do not absorb or only absorb below 200 nm, and thus cannot be detected by UV spectrophotometry [2]. Total phenolic compounds concentrations were between 25.6 and 35.1 mg/L, color 2.6 (AU), concentration of 0.2-mg TSS/L and lignin derivatives (UV 272 and UV 280 ) and aromatic compounds (UV 254 ).…”

“…Secondary treatment removes BOD 5 and COD in the ranges of 73-99% and 30-50%, respectively [1][2][3]. However, some refractory compounds have been found even after secondary treatment (aerated lagoon, activated sludge).…”