Strategies for Decolorization and Detoxification of Pulp and Paper Mill Effluent

Abstract

The potential hazards associated with industrial effluents, coupled with increasing awareness of environment problems, have prompted many countries to limit the indiscriminate discharge of untreated wastewaters. The pulp and paper industry has been among the most significant of industrial polluters of the waterways, and therefore has been one of the industries of concern. The pulp and paper industry produces large quantities of brown/black effluent that primarily result from pulping, bleaching, and paper-making production stages. The dark color and toxicity of pulp-paper mill effluent comes primarily from lignin and its chlorinated derivatives (e.g., lignosulphonic acid, resins, phenols, and hydrocarbons) that are released during various processing steps of lignocellulosic materials. The color originates from pulping and pulp bleaching stages, while adsorbable organic halides (AOX) originates exclusively from chlorine bleaching. Discharge of untreated effluent results in increased BOD/COD, slime growth, thermal problems, scum formation, discoloration, loss of aesthetic quality and toxicity to the aquatic life, in the receiving waterbodies. The dark brow color of pulp-paper effluent is not only responsible for aesthetic unacceptability, but also prevents the passage of sunlight through colored waterbodies. This reduces the photosynthetic activity of aquatic flora, ultimately causing depletion of dissolved oxygen. The pulp-paper organic waste, coupled with the presence of chlorine, results in the generation of highly chlorinated organic compounds. These toxic constituents of wastewater pose a human health risk through long term exposure. via drinking water and\or through consumption of fish that can bioaccumulate certain pollutants from the food chain. Therefore, considerable attention has been focused by many countries on decolorization of paper mill effluents , along with reduction in the contaminants that pose human health or other environmental hazards. Various physicochemical remediation treatments in the pulp-paper industry are now used, or have been suggested, but often are not implemented, because of the high cost involved. More recently, the paper and pulp industry has been investigating the use of biological remediation steps to replace or augment current treatment strategies. Certain biological treatments offer opportunities to reduce cost (both capital and operating), reduce energy consumption, and minimize environmental impact. Two primary approaches may be effective to curtail release of toxic effluents: first, development of pulping and bleaching processes that emphasize improved oxygen delignification or biopulping, plus partial or complete replacement of chlorine treatment with hydrogen peroxide or with biobleaching; second, implementation of biological processing that involves sequential two-step anaerobic-aerobic or three-step aerobic-anaerobic treatment technologies at end of pipe. The selection of the specific process will depend upon the type of pollutants/toxicants/mutagens present in the eff...

Wastewater Treatment and Reclamation: A Review of Pulp and Paper Industry Practices and Opportunities

“…Many of these compounds may have some adverse effects on the receiving media, such as formation of slime and scum, toxic effects to the exposed living organisms, and thermal impacts (Ali and Sreekrishnan 2001;Catalkaya and Kargi 2008;Garg and Tripathi 2011) or they are highly colored (Bajpai and Bajpai 1994).…”

“…The consortia of bacteria present in a properly operating wastewater treatment plant may be accompanied by protozoa, fungi, and rotifers (Chakrabarti et al 2008). Such a combination can be expected to allow the system to deal effectively with a wide variety of pollutants, which are likely to shift from hour to hour.Various authors have found favorable effects when using white-rot fungal species to treat pulp mill wastewater and bleach plant effluents (Eriksson and Kolar 1985;Pellinen and Joyce 1990; Duran et al 1994;Gökçay and Dilek 1994;Wolfaardt 1994;Marwaha et al 1998;Saxena and Gupta 1998;Taseli and Gökçay 1999;Sakurai et al 2001;Pokhrel and Viraraghavan 2004;Thakur 2004;Wu et al 2005;Malaviya and Rathore 2007;Freitas et al 2009;Singhal and Thakur 2009;Garg and Tripathi 2011;Kakahi et al 2011;Liu et al 2011;Souza et al 2014;Hossain and Ismail 2015;Kamali and Khodaparast 2015). Eriksson and Kolar (1985) observed much more favorable effects from the addition of a white-rot fungal strain, in comparison to two bacterial mixtures; the fungus promoted more rapid degradation of chlorolignins.…”

“…The sources and types of colored compounds that develop during pulping and papermaking have been reviewed (NCASI 2011). Measures to remove color from the effluent of P&P mills have been reviewed and reported (Bajpai and Bajpai 1994;Garg and Tripathi 2011;Garg et al 2012). Langergraber et al (2004) discussed the evaluation of color in such wastewater by instrumental methods.…”

Biosorption optimization and equilibrium isotherm of industrial dye compounds in novel strains of microscopic fungi

“…The ability of these microfungi to grow in an alkaline environment is an advantage from a practical point of view. This is due to the fact that many dye industrial wastewater is alkaline (Da Re and Papinutti 2011;Garg and Tripathi 2011). Therefore, obtaining strains, such as H. haematococca, effectively decolourizing the dyes and alkali lignin under alkaline conditions, is a major achievement in this field.…”

Microbial dechlorination of chloroorganics and simultaneous decolorization of pulp–paper mill effluent by Pseudomonas putida MTCC 10510 augmentation

“…Several physicochemical methods have been reported to be effective for reducing color in and toxicity of paper mill wastewater Garg and Tripathi 2011). However, these methods have not been implemented at an industrial scale, mainly because they are energy intensive and cost prohibitive ).…”