Case study, horticulture and aquaculture
Water reuse, coliform, E. coli and algae reduction
Hydro2050 trials at two horticultural facilities to assess the effectiveness of treating recycled and wastewater to improve water quality.
What the water reuse trials found
What the trials set out to show
The trials demonstrate the potential for Hydro2050 technology to improve the quality and reusability of recycled horticultural irrigation water through a single treatment process delivering complementary benefits: a 99.9% reduction in CFU, significant algae control, significant E. coli reduction, and high dissolved oxygen.
These results support the potential application of the technology in protected horticulture and community wastewater reuse, where maintaining clean, highly oxygenated recycled water is critical for safe, efficient water reuse and plant production.
The challenge
The challenge was to ensure recycled water could be effectively reused, for irrigation or as wash water, by improving its quality. In particular, the recycled water presented multiple key issues.
High microbial and pathogen loading
Untreated water contained an average of 32,500 colony forming units per millilitre, providing disease and pathogen risk for people, animals and plants.
High E. coli loading
200,000 MPN per 100 mL.
Algae contamination and regrowth
Algae was present in the recycled water, creating a need for both immediate control and suppression of subsequent regrowth. High algae growth causes irrigation blockages and potentially odour issues in more sensitive environments.
Low dissolved oxygen
Initial dissolved oxygen was only 4.95 mg/L, well below what is required for supporting healthy plant growth.
The results
These trials demonstrated strong improvement in recycled and wastewater water quality.
99.9% reduction in CFU
Mean colony forming units fell from 32,500 CFU/ml to 35 CFU/ml by the time 30 mg/L dissolved oxygen was achieved, and to 33 CFU/ml post-treatment.
99.9% reduction in E. coli
Reduction in E. coli from 200,000 MPN/100mL before treatment to 380 MPN/100mL after treatment.
Effective algae control
Algae was reported as eradicated at treatment, with significantly reduced regrowth in treated water compared with untreated water over the following days.
Before and after treatment
32,500 to 33
Colony forming units per ml
200,000 to 380
E. coli, MPN per 100 mL
The impact
Hydro2050 demonstrated the ability to transform recycled and wastewater into cleaner, with substantially reduced microbial contamination and algae, highly oxygenated water, enabling more effective water reuse while supporting healthier growing conditions and reducing water management challenges.
Cleaner recycled water
CFU and E. coli levels were reduced by 99.9%, reducing the microbial load and harmful bacteria.
Reduced algae pressure
Treatment eradicated algae at the time of treatment and significantly reduced subsequent regrowth, helping maintain cleaner recycled water and irrigation systems.
Highly oxygenated water
Dissolved oxygen reached elevated levels above 30 mg/L and remained elevated for several days, providing a means of maintaining highly oxygenated recycled water.
Greater potential for water reuse
By simultaneously addressing microbial contamination, algae and oxygenation, the Hydro2050 treatment can make recycled water more suitable for continued reuse, supporting sustainability and efficiency initiatives.
Horticulture and Aquaculture
Recycled water, cleaned and oxygenated in one pass.
A second horticultural study, at SA Tomatoes, reports the same starting values against irrigation water.