Case Study Type
Drinking Water - Ground Water Treatment
Client
Kibbutz Sdot Yam, Israel
Capacity
1,800 m3/d
Start-Up
2013
Overview
Kibbutz Sdot-Yam is located on the coast line of Israel, just south of Caesarea. A Nitrate-contaminated closed well was in need for drinking water supply to the area.
Aqwise, supported by Mekorot, the Israeli national water company, operated a pilot plant in 2009-2010, designed to study biological Nitrate removal from well-water, using a Moving Bed Biofilm Reactor (MBBR).
Requirements
Providing high quality and safe drinking water with Nitrate levels meeting drinking water norms.
Solution
Well water is pumped to a Hydrocyclone in order to remove sand and then enters the biological treatment: pre-anoxic reactor (Deox), followed by an anoxic stage where nitrate (NO3) is converted to Nitrogen gas (N2) which is released to the atmosphere, with no adverse impact on the environment.
Both pre-anoxic and anoxic reactors are continually mixed and contain Aqwise biomass carriers with different fill ratios. To enable microbiological growth on the Aqwise biomass carriers, Ethanol (external Carbon source) and phosphoric acid (external P source) are dosed to the pre-anoxic reactor, ensuring the stoichiometric ratio of C:N:P required for effective biological activity.
The treated water, with reduced nitrate levels is analyzed on-line to indicate the biological treatment performance. The water then enters to pre-filtration unit followed by an ultra-filtration (UF) membrane separation system, in order to remove suspended solids and any remaining micro-organisms from the water.
The recovery rate of the UF system is 92%. The UF backwash water does not contain elevated levels of salts or nitrate and therefore can be discharged to the sewer and/or used for irrigation.
Results
The required quality and quantity of water is provided by the Aqwise system 24/7, meeting all the norms and regulations.