Modular treatment solution delivers clean water under challenging conditions
- April 25, 2018
- Category: Water Treatment, Technology, Europe
Siltbuster Process Solutions (SPS) has developed a modular treatment solution, in collaboration with Suez for fertiliser manufacturer Yara Italia, providing clean water from a highly variable natural source.
By working closely with Suez Water Technologies & Solutions (formerly GE Water), SPS successfully provided up to 540m3/hr of clarified water for Suez’s Build-Own-Operate plant at Yara Italia’s production facility in Ferrara, Italy.
The site, which is located in the heart of the Po valley, is the market leading producer of ammonia and urea fertilisers for agriculture and industry. Suez was contracted to provide the site with demineralised water for the manufacturing process, abstracting raw water from the river Po.
SPS was called in to relieve the pressure on Yara’s existing clarifier, which was already treating approximately 1000m3/hr, and more importantly, to provide a dedicated, high quality water supply.
The early stages of the project were challenging, as it became apparent that the characteristics of the raw water varied significantly, sometimes within a matter of a few hours.
Dr Chris Bullen, Technical Manager at SPS, explained:
“The river water turbidity can range from less than 20NTU to over 3000NTU within a short period of time. This, coupled with seasonal changes to the characteristics of particulates in the water, added to the challenge of coming up with a robust solution.”
As the project commenced, it became clear that a pilot trial was required in order to arrive at the correct long-term solution. This was achieved by deploying one of SPS’ mobile lamella clarifier units, complete with integrated coagulation/flocculation tanks. It was essential that the pilot unit remained on site for long enough to capture the variable conditions, and during this period, it was operated by Suez’s dedicated site team led by Fabio Armanna, with the technical support provided by SPS.
The trial concluded that satisfactory water quality (less than 5NTU) could be reliably and consistently achieved, under highly variable conditions, with the use of the lamella clarifiers. The trials also confirmed that incorporating a means of recirculating settled solids from the bottom of the clarifier hopper back into the mixed reaction tank, to combine with the feed water, improved the stability of the process and quality of treated water.
Dr. Bullen explained:
“The findings of this piloting work enabled us to confirm the design of the full-scale process, which required three process streams, each with a mixed chemical reaction tank carefully coupled with a Siltbuster HB200R Lamella Clarifier. The design also needed to comply with stringent structural design requirements to comply with the Regulatory Authorities’ requirements for the Seismic Area.
“The strength of the partnership approach meant that Suez’s local project team led by Maurizio Colombo were able to use Siltbuster’s design drawings to liaise with the Italian Authorities regarding these aspects, to secure the necessary approvals.”
Process commissioning was completed in December 2017, with the treated water achieving less than 3NTU. Suez’s site team has also identified that the downstream treatment processes are already benefiting from the improved water quality.