This article describes an effective procedure for reducing the water content of excess sludge production from a wastewater treatment plant by increasing its concentration and, as a consequence, minimizing the volume of sludge to be managed. It consists of a pre-dewatering sludge process, which is used as a preliminary step or alternative to the thickening. It is made up of two discontinuous sequential stages: the first is resettling and the second, filtration through a porous medium. The process is strictly physical, without any chemical additives or electromechanical equipment intervening. The experiment was carried out in a pilot-scale system, consisting of a column of sedimentation that incorporates a filter medium. Different sludge heights were tested over the filter to verify the influence of hydrostatic pressure on the various final concentrations of each stage. The results show that the initial sludge concentration may increase by more than 570% by the end of the process with the final volume of sludge being reduced in similar proportions and hydrostatic pressure having a limited effect on this final concentration. Moreover, the value of the hydrostatic pressure at which critical specific cake resistance is reached is established.

中文翻译：

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废活性污泥分批沉降过滤减水。阶段 (1)：中试规模实验以优化性能

本文介绍了一种通过提高废水处理厂剩余污泥的浓度来减少其产生的剩余污泥的含水量的有效程序，从而最大限度地减少要管理的污泥量。它包括预脱水污泥过程，用作浓缩的预备步骤或替代方法。它由两个不连续的连续阶段组成：第一个是重新安置，第二个是通过多孔介质过滤。该过程是严格的物理过程，没有任何化学添加剂或机电设备干预。该实验是在一个中试规模的系统中进行的，该系统由一个包含过滤介质的沉淀柱组成。在过滤器上测试了不同的污泥高度，以验证静水压力对每个阶段不同最终浓度的影响。结果表明，到过程结束时，初始污泥浓度可能增加 570% 以上，最终污泥体积以相似的比例减少，静水压力对该最终浓度的影响有限。此外，确定达到临界比滤饼阻力时的静水压力值。