Automation of Dewatering and Impacts on Overall Cost

Water resource recovery facilities (WRRFs) face increasingly stringent regulations and pressure to reduce costs. In this environment, WRRFs of all sizes can benefit from targeted and proven automation that can be used to optimize process efficiency. This can simultaneously provide “real-time” information while freeing plant staff from time-consuming sampling and analysis. Dewatering represents significant operational costs for most WRRFs because of the associated hauling and chemical costs. Some thickening processes also utilize chemical conditioning, and therefore represent operating costs. The proportional costs related to dewatering and thickening relative to overall WRRF operating costs are included in Figure 1 under sludge transport and disposal and portions of the chemical, electricity, and labor values. Targeted sensors and control systems that can optimize thickened sludge concentration or dewatered cake dryness and polymer dose can save WRRFs substantial operational costs.