Wastewater Reuse Solutions
The Next Generation of Wastewater Reuse Technology
Water is a precious commodity in a world facing increased water demand alongside global climate change. One of the ways to supply the increased water demand is to reuse the wastewater effluent by Indirect Potable Reuse (IPR), such as aquifer recharge or Direct Potable Reuse (DPR). Other uses such as irrigation or industrial reuse are also possible clients of this high quality product water.
IDE offers advanced water reuse systems that produce water that is safer than the current state-of-the-art in the field, and utilizes proprietary means to operate systems that are more cost effective in both installation and operational costs. Through a robust and highly controlled process, the water produced in these systems can exceed the quality of natural drinking water, since it passes through process steps that filter and disintegrate organic contaminants that might be present in natural water bodies (as a result of anthropogenic actions).
The conventional wastewater reuse process
The conventional wastewater reuse process (also termed FAT – Fully Advanced Treatment) to treat municipal wastewater effluent usually consists of Ultrafiltration (UF), Reverse Osmosis (RO) and an advanced oxidation step (UV/AOP). In order to control biofouling on the membranes, chloramine is dosed to the feed water. However, chloramine also serves as a precursor to the formation of NDMA, a dangerous organic contaminant and a suspected carcinogen, the presence of which is allowed in water at a level above 10 ng/l (according to US regulations). In addition, Chloramine reduces the UVT value (the clarity level) of the permeate water, which increases the energy demand in the UV/AOP system as well as requires a larger UV/AOP system. This is, of course, not enough to maintain the system in good operating condition, therefore a periodic Cleaning in Place (CIP) process is required. This process requires shutdown of the system and chemicals that later require neutralization and handling. Therefore, this process should be minimized as much as posiblle.
Unique Features of SARP Technology
Preventive maintenance as a means to a clean, efficient and safe wastewater reuse system
IDE believes that a process with minimal impact on the environment is a better, safer and more stable process. Therefore, we use a preventive maintenance approach. In this approach, the system is constantly cleaned so that chloramine dosage is not required and the CIP intervals are longer. This allows the system to be more energy-efficient, as well as minimizes its environemtal impact. In an analogy to human life, one can look at this approach as “brushing your teeth daily is better than going to the denstist every 6 months for treatment”.
The mechanisms of this approach are:
- DOHS – Direct Osmosis High Salinity – Injection of a short pulse of concentrated saline solution that causes:
- Backwash of the membrane surface by forward osmosis
- Rapid increase in cross flow velocity (shear force)
- Bacteria dehydration due to osmotic shock
2.Conservation – periodic flushing of the membrane with permeate to dissolve scaling
IDE’s Ecological Fully Advanced Treatment process (ECO FAT) Technology – environmentally superior wastewater reuse process
The ECO FAT process operates without any chloramine dosage. Instead it uses the described DOHS and conservation mechanisms to control fouling formation. This process offers the following advantages:
ECO FAT can be retrofitted in existing wastewater reuse facilities to improve their process and produce a safer product, as well as in new installations that want to use state-of-the-art technology in the water reuse field.
Sustainable Advanced Reuse Process (SARP) technology
Following the approach of minimal impact on the environment, the SARP technology uses the same concept of preventive maintenance mechanisms and takes this one step further – instead of using the conventional UF/MF pretreatment, a media filter (that does not require chemicals for backwash and cleanings) is used. Of course, no chloramines are dosed to the system, making it a very green wastewater reuse process.
This solution is aimed mainly for tertiary effluent or certain industrial effluents.
Key Features of SARP
IDE’s advanced wastewater reuse technologies in Pismo Beach, CA
Pismo beach WWTP hosts IDE’s demonstration site for its wastewater reuse technologies. This demo site serves to demonstrate the technology on municipal secondary effluent, fed to either the FAT, ECO FAT or SARP processes.