Moving bed biofilm reactor for treatment of Kraft pulp effluent with high organic load rate

Camila Peitz,Claudia Regina Xavier

doi:10.4136/ambi-agua.2512

Abstract

The pulp industry uses more than 40 m3 of water per ton of pulp produced, generating high effluent flows. In general, it presents high concentrations of organic matter, color and ecotoxicity. The most widely used effluent treatment systems in the pulp industry are biological, including moving bed biofilm systems that are efficient in removing biodegradable organic matter. This work evaluated the removal of organic matter, total phenolic compounds, color and lignin derivatives in the treatment of Kraft cellulose effluent using the moving bed biofilm reactor (MBBR), and also evaluated the support media biofilm development by solid analysis and scanning electron microscopy. The parameters evaluated during treatment were: BOD5, COD, color, total phenolic compounds, lignin derivatives, and solids, with tests performed on organic loads from 0.7 and 8.9 kgCOD m-3 d-1. Organic matter removal remained stable, being over 80% to BOD5 and over 42% to COD. The color and the total phenolic compounds were removed up to approximately 7 and 28%, respectively. Over 19% removal of derivatives of lignin compounds was observed in both organic load rates. In the MBBR, biofilm was confirmed and enabled this biological system to treat the cellulose effluent in a stable way.

Highlights

The Kraft pulping process is the most widely used pulp production in the world
The removal efficiency of organic matter remained stable in relation to COD, remaining above 40%, not presenting large discrepancies between the applied loads, constituting moving bed biofilm reactor (MBBR) with APG as a stable system
Considering the removal of BOD5, a drop of 7.7% being justified by the low biodegradability of treated Kraft pulp effluent, showing the stability of the system in load shocks

Summary

Introduction

There is high water consumption in the pulp industry, as more than 40 m3 of water is consumed per ton of pulp produced, which in turn generates large volumes of effluent. This effluent is rich in organic matter, suspended solids, resin acids, lignin, color and ecotoxicity (Bachmann, 2009; Bakraoui et al, 2020; Furley et al, 2015; 2018; Hossain and Ismail, 2015; ToczyłowskaMamińska, 2017). The support media applied in this type of biological treatment are generally made of high-density polyethylene or polypropylene They are inert and have a high specific surface area (>1000 m2 m-3) (Leyva-Díaz et al, 2017)

Methods

Results

Conclusion