Abstract

The electrodialysis reversal (EDR) technology was applied as tertiary treatment for final effluent from a Kraft pulp mill industry located in Bahia, Brazil. Two samples were evaluated: first, the final effluent treated by conventional processes (FE); the second one was additionally filtered by sand and activated carbon (FEAC). The tests in a pilot plant were carried out in batch mode, with electrode’s polarity reversion. Temperature, pH and electrical conductivity measurements were performed during EDR treatment. Solutions before and after the EDR treatment were submitted to physicochemical characterization in order to determine the system efficiency. Chloride and sulfide concentrations have been reduced by up to 98.6 and 100% respectively. Only for FE treatment it was observed fouling and scaling occurrence, due to high organic and inorganic ions concentrations. In addition, the evaluated ions were satisfactorily removed by EDR for both effluents, giving to them the suitable quality for disposal or reuse in industrial processes. The study presents a mitigating solution to environmental and technological problems, itself as a viable alternative in the tertiary treatment of effluents from the Kraft process in the pulp industry.

摘要

逆向电渗析 (EDR) 技术被用作对位于巴西巴伊亚的牛皮纸制浆厂的最终废水进行三级处理。评估了两个样品：首先，通过常规工艺 (FE) 处理的最终出水；第二个用沙子和活性炭（FEAC）额外过滤。中试工厂的测试以分批模式进行，电极极性反转。在 EDR 治疗期间进行温度、pH 值和电导率测量。EDR 处理前后的溶液进行物理化学表征以确定系统效率。氯化物和硫化物的浓度分别降低了 98.6% 和 100%。仅对于 FE 处理，观察到结垢和结垢发生，由于有机和无机离子浓度高。此外，经 EDR 对两种流出物的评估离子都得到了令人满意的去除，使它们具有合适的质量，可以在工业过程中进行处置或再利用。该研究提出了一种缓解环境和技术问题的解决方案，它本身是纸浆行业 Kraft 工艺废水三级处理的可行替代方案。