Study of the impacts of process changes of a pulp and paper mill on aerated stabilization basin (ASB) performance

Abstract

A laboratory scale (LS) and a field-based pilot plant (PP), designed to simulate aerobic stabilization basin (ASB) operation, were utilized to assess the potential impacts of changes in pulp and paper (P&P) mill operations on full-scale (FS) ASB performance. Two stages of investigation were conducted. The first was undertaken to determine the potential of pre-alum treatment of pulp mill wastewaters on ASB performance. The second investigation was conducted to assess ASB performance where wastewaters transitioned from being coagulated pulp and paper mill wastewaters to paper mill wastewaters only. Simulation ASB performance was assessed based on removals of BOD, colour, UV@254 nm and nutrients [total phosphorus (TP) and nitrogen compounds (TN)]. Pre-alum treatment of pulp mill wastewaters with subsequent ASB treatment following mixing with paper mill wastewaters showed high percentage removals of BOD. Despite low TP concentrations (≤0.05 mg/L) and low nutrient to BOD ratios of wastewaters in the LS-ASB trial, the high % BOD removal indicated recycling of nutrients from sludge [sourced from the FS-ASB]. Despite coagulation of pulp mill wastewater being performed using a very high alum dose (∼2000 mg/L) to remove colour and its precursors, colour formation remained high throughout the simulated ASB trials. Simulation of discontinuation of pulping indicated that colour would reduce rapidly to low levels in ASB wastewaters, but that TP and TN concentrations would persist for longer periods of time and decline slowly. Survey data of water qualities of the FS-ASB system obtained before, during and 2 years after discontinuation of pulping are presented.

Microbiological diversity in an aerated lagoon treating kraft effluent

“…The analysis of TOC removal averaged 49% for the AFL with OLR of 0.2 kgCODm -3 d -1 . The results obtained in such OLR were similar to the result found by Lewis et al (2018) in an aerated facultative lagoon.…”

“…The increase observed in the first 10 d of operation is related to the stabilization of the treatment system. The increase in color may be related to the process of biotransformation of chromophoric units and the condensation of color-forming compounds, without mineralization of the effluent (Lewis et al 2018;Peitz and Xavier 2020). Low color removal has been observed during treatment by aerated lagoons (Kamali and Khodaparast 2015;Peitz and Xavier 2020).…”

“…Except for the biological ones, these methods are expensive, which often makes their application unfeasible (Kamali and Khodaparast 2015;Kamali et al 2019). Sonkar et al 2019 Activated sludge and aerated facultative lagoon (AFL) processes are the most used systems in the biological treatment of effluents from the pulp and paper industry (Kamali and Khodaparast 2015;Bailón-salas et al 2017;Lewis et al 2018). In this sense, AFLs are widely used in Brazil due to the country's favorable climatic conditions and the large availability of area for the construction of these lagoons (Von Sperling 2016).…”

Evaluation of aerated lagoon modified with spongy support medium treating Kraft pulp mill effluent

“…The analytical parameters were: Biochemical Oxygen Demand -BOD 5 and Chemical Oxygen Demand -COD [18]; Total Phenolic Compounds -TPC (UV 215nm ), colour (Vis 440nm ), aromatic compounds (UV 254nm ), lignin derived compounds (UV 280nm ) and lignosulfonic acid (UV 346nm ) [19,20], in samples filtered with nitrocellulose membrane of 0.45 µm porosity, which were monitored during continuous biological treatment.…”

“…This has been related to the polycondensation-adsorption of lignin structures, which would occur simultaneously with a mechanism of filterable colour formation due to the biochemical oxidation of some functional groups of lignin [28]. Other authors have argued that, during treatment, the organic matter that is not removed through biodegradation can be modified for chromophoric units instead of mineralized and, consequently, leads to an increase in the level of colour [20,29].…”