Characterization of Ecotoxicological Effects of Green Liquor Dregs from the Pulp and Paper Industry

Abstract

Green liquor dregs (GLD) are a major waste of the pulp and paper industry, and their correct classification is important to finding alternatives to landfill disposal. In the European Union, the methodology to determine the hazard property HP 14 (“ecotoxic”) is under discussion. Although biological tests are likely more representative of wastes’ environmental behavior, there are still no official guidelines on procedures, and ecotoxicity classification relies on the chemical composition. This work aimed to evaluate the ecotoxicity of GLD to determine HP 14. The assessment comprised a chemical analysis (using ClassifyMyWaste software) and a battery of biotests targeting aquatic ecosystems (Lepidium sativum, Aliivibrio fischeri, Raphidocelis subcapitata, Lemna minor, and Daphnia magna). The chemical analysis denoted GLD as a “Possible Hazard,” while the battery of biotests showed high ecotoxic effects for three out of five organisms, the most sensitive being Lepidium sativum, Lemna minor, and Daphnia magna. The pH correction of tested eluates to neutral values did not modulate the noticed effects. Globally, the results suggest that GLD should be classified as ecotoxic. Though, the European waste legislation should provide guidelines to apply the end-of-waste criteria and avoid landfilling even for materials like GLD.

Assessment of the environmental acceptability of potential artificial reef materials using two ecotoxicity tests: Luminescent bacteria and sea urchin embryogenesis

“…First, the marine Luminescent Bacteria Test with Vibrio fischeri obtained as freeze-dried bacteria. It is a representative microorganism of the marine aquatic environment, used mainly for a rapid determination of the toxicity of different waste materials (Schiavo et al, 2018;Bandarra et al, 2019). Due to its high sensitivity for toxicity in organic extracts, this test is a good candidate for the screening step (Weltens et al, 2014;Manzano et al, 2017).…”

Utilization of Calcite-rich Green Liquor Dregs (GLD) by-products From Pulp and Paper Industry: Cement Clinker Production and Life Cycle Analysis

“…Landfilling is the presently dominant approach to managing paper and pulp industry side-streams like Green Liquor Dregs (GLD), lime residue, and ashes. In this context, it is notable that GLD is considered non-hazardous waste according to the European list of wastes as well as by the Confederation of European Paper Industry (CEPI) [8]. However, it can have significant emissions to air and water [9][10][11].…”

Bioprocessing of Oat Hulls to Ethylene: Impact of Dilute HNO3- or NaOH-Pretreatment on Process Efficiency and Sustainability

“…Although H 2 SO 4 is most commonly used for acid pretreatment, , its waste is unsustainable. , Therefore, chemicals with a less negative environmental impact, such as nitric acid, are more promising . Dilute HNO 3 is effective for pretreatment of biomass, , and in some cases, even more effective than H 2 SO 4 .…”