A novel energy recovery device/RO test rig targeted to treat recoup low industrial wastewater flows.

摘要

Freshwater withdrawals have tripled over the last 50 years, and demand is increasing by over 64 billion cubic metres year on year. Demand for water is led by agriculture (70%), followed by industry (20%) and domestic use (10%)[1]. Increasing water stress, predicted by the United Nations Environment Programme [2], means that these levels of withdrawal are not sustainable. As a result, other water sources, such as seawater desalination, wastewater reuse and recycle, are being utilised to meet demand. Water reuse and recycle are options to help close the loop on water engineering systems, thus mitigating freshwater extraction. Water treatment requirements, and the associated energy requirements to treat water or wastewater to designated standards, vary according to application. Typically the energy requirements are a function of scale, technology, incoming water quality, and water quality requirements (product). Of the widely used technologies, Reverse osmosis (RO) is relatively low in terms of energy consumption, at least in comparison with traditional thermal processes such as Multi-Stage Flash (MSF) or Multi-Effect Distillation (MED). The use of energy recovery devices in RO processes to recoup energy from the pressurised brine flow has led to a further reduction in the overall energy footprint of the technology. However, the common energy recovery device technologies are often targeted at high flow rate applications such as seawater RO. The objective of this research is to design an RO system that is suitable to treat wastewaters from differing water sources (varying levels of BOD and salinity). This RO system will incorporate a novel energy recovery/pump device, which is suitable for the treatment of small wastewater flows. As part of the SaltGae project [3] the novel ERD & RO test rig will be trialled in two sites: a Tannery in Slovenia and an Aquaculture system in Israel.