A major edible oil processor with multi locational manufacturing facilities in India uses reverse osmosis (RO) for its process water requirement. They were experiencing RO element fouling, frequent downtime, excessive clean-in-place (CIP) requirements and was replacing expensive RO elements every alternate year. The used to limit the edible oil production due to short supply of RO treated water.
SUEZ WTS along with its channel partner Aroma Speciality conducted a complete audit of the system to check hardware's integrity and cross-check RO skid process design using Winflows software. The study of the chemical pretreatment and CIP procedure revealed significant deficiencies.
The raw water from various sources were analyzed. As COD in all raw water sources was negligible, Sodium Hypo chloride and SMBS dosing were discontinued.
Silt density index (SDI) was immeasurable at the RO feed. There was no change in SDI and turbidity across the sand filter. The sand filter was opened for inspection and it was observed that the filtering media was hardened leading to channeling and non-functioning of the same. Reducing SDI well within acceptable limit at less than 4.0, was a real challenge as turbidity of water was less than 2 NTU. The raw water storage tank was cleaned and disinfected to eliminate contamination of water in raw water storage tank and the filter media of sand filter was changed.
Due to low turbidity in raw water and nonviability of coagulation tank we introduced SUEZ WES cationic coagulant at the inlet of Sand filter. The SDI at the Sand Filter outlet came down to less than 3, which is well within the limit suggested by RO element manufacturers. SUEZ WTS introduced the proven cost effective antiscalant, Hypersperse MDC220 at a dosage of 4ppm.
On streamlining the pretreatment, the RO elements were replaced with SUEZ WTS AG8040F. Additionally, SUEZ WTS, established site specific cleaning regime to target colloidal, mineral deposits and biological fouling, using Suez WTS proprietary alkaline and low pH cleaning products.
The detailed plant audit and various corrective actions taken resulted in achieving consistent SDI fo RO feed water. SUEZ WTS RO elements AG8040F installed in 2010 are still being used for last 8 years producing required RO treated water to customers satisfaction with enhanced reliability of plant operation.
- CIP frequency was reduced from every 2 weeks to 3 months
- Extended RO element life from earlier 2 years to more than 8 years
- Reduction in CIPs and optimizing the chemical consumption have drastically reduced operating cost
The customer is delighted with SUEZ WTS products and service support of Aroma Speciality and now they are using our products at all their other problems.