Characteristics and treatment of Brazilian pulp and paper mill effluents: a review

Abstract

Pulp and paper industries are very important for developing the Brazilian economy. During production processes, many effluents are generated with high polluting potential. The objective of this study is to conduct an extensive literature review on the characteristics of effluents and treatment forms adopted by Brazilian mills in this industrial sector. Most consulted studies address raw (without treatment) and secondary (after biological treatment) effluents, considering their main characteristics like pH, chemical and biochemical oxygen demands (COD and BOD, respectively), color, solids, organochlorines, toxicity, estrogenic activity, and phenols. Raw effluents differ considerably in composition, depending on the type of paper produced, the pulping process employed, and other steps, like pulp bleaching. Raw effluent characteristics indicate that this effluent cannot be directly disposed of into water bodies, because it does not comply with federal and state disposal standards. Secondary effluents normally comply with Brazilian legislations, although some studies have reported COD and total phenol concentrations higher than disposal standards, suggesting that additional treatments are necessary. Treated effluent reuse was verified in some Brazilian mills, while its disposal in eucalyptus plantations has been considered a promising alternative for irrigation purposes.

Sustainable Utilization of Pulp and Paper Wastewater

“…Chemical pulp involves the separation of lignin from fibrous material to obtain cellulose by exposing papermaking materials to chemicals. This method is highly productive and extensively employed in the paper industry, accounting for ~75% production of the total industrial and commercial paper in the market [11]. However, this method produces a large amount of wastewater.…”

Desenvolvimento de membrana cerâmica de microfiltração a partir de resíduo de casca de arroz e caulim e aplicação como pré-tratamento de efluente da indústria de papel

“…A indústria de fabricação de papel se caracteriza como uma das maiores fontes poluidoras, devido à geração de efluentes líquidos com potencial de contaminação ambiental, tanto em habitats marinhos quanto terrestres (HAQ; KALAMDHAD; PANDEY, 2022). As águas residuárias desse processo industrial são caracterizadas por apresentarem concentrações de demanda química de oxigênio, fenóis totais, sólidos em suspensão, cor e demais compostos contaminantes bem acima dos limites estabelecidos pela legislação (RAMOS et al, 2022).…”

“…De modo geral, os processos de tratamento de efluentes aplicados na indústria de papel consistem em processos convencionais, tais como os físico--químicos e biológicos. Visando à necessidade de uma remoção mais eficiente nas primeiras etapas do tratamento, bem como à minimização dos impactos nos corpos hídricos receptores, soluções mais eficazes para a remoção de contaminantes devem ser aplicadas (RAMOS et al, 2022). Dentre tais processos, a filtração por membranas apresenta-se como alternativa efetiva como pré-tratamento nessa primeira etapa (HEYDARIPOUR et al, 2019;SUN et al, 2015).…”

Box–Behnken Design-Based Optimization of the Saccharification of Primary Paper-Mill Sludge as a Renewable Raw Material for Bioethanol Production

“…Pulping processes have a high biological oxygen and chemical oxygen demand, and they are associated with the production of large quantities of wastewater which is highly toxic and which contains phenolic compounds, organochlorines, and solids. This wastewater is difficult to treat and poses a high environmental risk [6]. Each tonne of paper produced results in 40-50 kg of dry sludge, with 70% and 30% from primary and secondary sludge, respectively [7].…”

“…Each tonne of paper produced results in 40-50 kg of dry sludge, with 70% and 30% from primary and secondary sludge, respectively [7]. Generally, the primary paper-mill sludge generated from the clarifier of the effluent treatment plants has short fibers, clays, and filler materials [6,7]. Secondary sludge is mainly generated from wastewater treatment operations (biological treatment), which is separated in the secondary decanter and is rich in microbes, proteins, minerals, and polysaccharides [6,7].…”