Proposal for water reuse in the Kraft pulp and paper industry

Abstract

The reuse of wastewater by the pulp and paper industry reduces environmental impacts by contributing to raw water conservation, thereby making a greater volume of fresh water available for nobler purposes, and reducing wastewater treatment. This study evaluated a proposed system of water reuse at a Kraft pulp and paper plant in Brazil, based on a survey of water quality required by its consumption points, supplied by its water treatment plant. Results after ultrafiltration included: turbidity of 0,3 NTU and pH 7,5, average values of BOD 66,4 mg/L, COD 9,6 mg/L and the colour of 280,5 ppm Pt were measured after ultrafiltration. The ultrafiltered wastewater was considered available for reuse, and its quality was compared with that of the water supplied by the water treatment plant, which provided for the classification of potential reuse points. Water colour was identified as the limiting factor for reuse; thus the reuse points were two Kraft paper machines, and the water flow to the liquid ring formations that generate the vacuums inside nineteen pumps for these two machines. The advantages of this proposal for water reuse include: ultrafiltered water quality sufficient for the vacuum pumps, the small distance between the point of reused water generation and the paper machines section, and the reused water has no contact with the final product. The calculated cost and return time for the water reuse system was US$ 607.020,00 in 15 years.

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

“…Primary treatment removes them via sedimentation. Furthermore, recovered fibers can be reused in paper manufacturing (Kossar et al, 2013 ; Tilha et al, 2019 ). Parts of the inorganic dissolved substances are sodium salts and bleaching agents (Mandeep et al, 2019 ), while dissolved organic substances are mostly lignin and hemicellulose fragments, and extractives, many of which are chlorinated due to the bleaching step with chlorine dioxide (Cabrera, 2017 ; Hubbe et al, 2016 ).…”

“…Some process steps need freshwater, while others require low-quality water (Li et al, 2016 ). Analyzing an industrial wastewater treatment plant, Kossar et al ( 2013 ) suggested reusing ultrafiltration-polished effluent in kraft paper machine showers and vacuum pumps, because the water does not enter into contact with the produced paper. The authors highlighted that the color of the treated effluent was the limiting factor for its reuse.…”

Identification of Foulants on Polyethersulfone Membranes Used to Remove Colloids and Dissolved Matter from Paper Mill Treated Effluent

“…Many authors have studied ultrafiltration as the main treatment to remove the dissolved and colloidal substances (DCS) concentrated during the recycling of white waters not treated by using biological treatment. The results show that in pulp and paper mill effluent (white water), DCS are considered to be the major membrane foulants [10][11][12][13][14][15][16][17][18].…”

Optimization of Operation Parameters in Ultrafiltration by Experiment Design, Mathematical Modelling and Fouling Characterization of the Membranes Used to Remove Dissolved and Colloidal Substances from a Treated Paper Mill Effluent

“…Biological process will modify organic substances presents in white waters and also will produce new organic substances from biological sludge. Hence, a good knowledge of characteristics substances present in these waters is important to help minimize membrane fouling (Kossar et al, 2013), aiming to obtain high quality water from UF filtration that may replace fresh water use in some applications. Furthermore, in the literature investigations about foulants characteristics had received little attention in comparison with studies focused on membrane performance and water quality.…”