Water Project of the Year
Zhangjiagang No.4 WTP, China
What is it?
An RMB920 million ($150 million), 100,000m3/d renovation and upgrade of a 400,000m3/d water treatment plant – significantly increasing the operating capacity and introducing ultrafiltration (UF) and nanofiltration (NF) treatment to help serve 1.5 million residents in the city of Zhangjiagang, Jiangsu Province in China.
Who is involved?
The project was delivered on an EPC basis by GreenTech Environmental for local utility Zhangjiagang Water Company. Shanghai Municipal Engineering Design Institute was responsible for the process design of the plant. Membranes were supplied by DuPont (NF) and local brand Litree (UF).
What makes it special?
The expansion makes the plant the joint largest nanofiltration membrane drinking water facilities in China on top of its existing capabilities, not only marking a new level of success for the technology, but setting the stage for its deployment in advanced drinking water treatment across the country. A further capacity phase of 200,000m3/d is now under construction, which will make the facility the largest of its kind in the world.
The NF upgrade enables the plant to provide a far higher quality of drinking water, originally sourced from a polluted downstream area of the Yangtze River which faces high turbidity and potential micropollutant risks. The plant defeats these environmental challenges, removing microorganisms, organics and disinfection byproducts, to lay a solid foundation for the city’s ambition to provide universal potable water coverage from taps.
Innovative digital technologies including digital twins featuring building information modelling (BIM) systems were adopted during the plant’s construction and operation phases, hugely improving the efficiency of building and operations, and enabling a stable performance with a market-beating high water recovery rate of 90%.
Distinction
Dominguez Channel, USA
What is it?
The emergency deployment of a chemical-free nanobubble water treatment system that rapidly remediated foul odours emanating from the Dominguez Channel in Los Angeles County, after chemical run-off from a major fire in the City of Carson brought hydrogen sulphide levels in the water to 230 times the state standard.
Who is involved?
Moleaer deployed its treatment system for the Los Angeles County Department of Public Works following over 4,000 odour complaints to the South Air Quality Management District. Subcontractors included Sunbelt Rentals, Bragg Crane, Herc Rentals, Pine Environmental, Ocean Blue Environmental and Agri Valley.
What makes it special?
When noxious, rotten-egg odours caused by a hydrogen sulphide spike in the Dominguez Channel resulted in the urgent relocation of 3,200 residents experiencing headaches, sore throats, nausea and burning eyes, LA County Public Works sought an emergency chemical-free solution. Where traditional, surface-breaking aeration of the shallow channel would have released toxic levels of hydrogen sulphide into the already-noxious air, Moleaer’s proprietary generators dispersed neutrally buoyant nanobubbles through the water, destroying hydrogen sulphide without off-gassing.
Spurred on by the impact of the incident on their community, Carson-based Moleaer mobilised and coordinated a huge effort with its service partners, dedicating 5,800 hours to fine-tuning deployment and building new generators. By rapidly upscaling its capacity, treating 60 million gallons of contaminated water per day with fourteen generators at the treatment’s peak, Moleaer achieved remediation of the Channel weeks faster than modelling had suggested, saving LA County millions in compensation to relocated residents.
Despite a storm pausing treatment for three days and increasing anaerobic conditions in the channel, Moleaer’s system returned the water to pre-incident hydrogen sulphide levels within just ten days. Four weeks into treatment, levels had dropped from a high of 7,000 down to 10 parts per billion, allowing residents to return home weeks sooner than anticipated by LA County.