Department of Civil Engineering, Universidade Federal de Viçosa, 36,570-900 Viçosa, Minas Gerais, Brazil.
Department of Forest Engineering, Universidade Federal de Viçosa, 36570-000 Viçosa, Minas Gerais, Brazil.
Sci Total Environ. 2021 Apr 1;763:142996. doi: 10.1016/j.scitotenv.2020.142996. Epub 2020 Oct 15.
A Brazilian thermo-mechanical pulp mill (TMP) was evaluating the installation of a proposed bleaching process, with changes in the qualitative and quantitative characteristics of the wastewaters and the Effluent Treatment Plant (ETP). The objectives of this research were to evaluate the treatment plant configuration for the future industrial effluent, consisting of a flotation unit followed by an upflow anaerobic sludge blanket reactor (UASB), an activated sludge process and nanofiltration (NF) using polymeric membranes, and to study the technical feasibility of recycling the treated effluents in the industrial process. The possible options for recycling the treated effluent were determined through a water balance of the mill. The pulp quality was evaluated in laboratory bleaching assays, based on brightness and brightness reversion tests after the recycling of 50%, 75% and 100% of the treated effluent. The buildup of the non-process elements (NPE) in the industrial water cycle after each effluent recycling proportion was evaluated through computer simulation, using the Aspen Plus® simulator software. The future mill effluent, considering the implementation of a proposed bleaching stage with hydrogen peroxide, was generated in the laboratory and treated in a bench-scale effluent plant, simulating the future configuration. The treatment plant removed 99.8%, 99.2% and 61.6% of soluble COD, BOD and color, respectively. The water consumption was highest in the bleaching plant and, therefore, the recycling of 50%, 75% and 100% of the treated effluent for washing the pulp was simulated. The brightness and brightness reversion of the pulp, with 100% of the treated effluent used in the bleaching process, were similar to those provided by fresh water. The recycling of 100% of the treated effluent in the proposed treatment plant was possible in the TMP pulp mill without decreasing the pulp quality.
一家巴西的热机械浆厂（TMP）正在评估拟议的漂白工艺安装，这将改变废水的定性和定量特征以及废水处理厂（ETP）。本研究的目的是评估未来工业废水的处理厂配置，该配置包括浮选单元，然后是上流式厌氧污泥床反应器（UASB）、活性污泥工艺和使用聚合物膜的纳滤（NF），并研究处理后的废水在工业过程中回收的技术可行性。通过工厂的水量平衡确定了处理后废水回收的可能选择。在实验室漂白试验中评估了纸浆质量，基于 50%、75%和 100%的处理后废水回收后的亮度和亮度反转试验。通过使用 Aspen Plus®模拟器软件对每个废水回收比例后工业水循环中的非工艺元素（NPE）的积累进行计算机模拟。考虑到实施过氧化氢拟议的漂白阶段，未来的工厂废水在实验室中生成，并在中试规模的废水处理厂中进行处理，模拟未来的配置。处理厂分别去除了 99.8%、99.2%和 61.6%的可溶性 COD、BOD 和颜色。耗水量在漂白厂最高，因此模拟了回收 50%、75%和 100%的处理后废水用于洗涤纸浆。用 100%的处理后废水进行漂白过程，纸浆的亮度和亮度反转与新鲜水相似。在不降低纸浆质量的情况下，在拟议的处理厂中回收 100%的处理后废水是可能的。
