In 2019, the government of São Paulo in Brazil committed to spend US$376 million cleaning up the city’s heavily polluted Pinheiros River. Next Filtration’s FOG Stop formulation was one of the products tested to see if it could make improvements to the river.
The Pinheiros River which runs through São Paulo is a tributary of the Tietê River and both rivers have suffered from pollution for many years. The Secretariat of Environment of the State of São Paulo requested a trial of the FOG Stop formulation in one of most heavily polluted and foul-smelling parts of the Pinheiros River.
To demonstrate its capacity to enhance environmental conditions, Next FOG Stop was applied at a purpose-built experimental channel next to a pumping station.
Successful reduction Following the application of FOG Stop, there was a complete absence of odours, reflected in a major reduction in the level of sulphide. Even in the first quarter of the trial, siltation was reduced dramatically.
A reduction in the concentration of nitrogen also indicated a lowered potential for eutrophication, as well as a decreased concentration of organic carbon. Efficiency rates of around 58% in the conversion of ammoniacal nitrogen were also achieved.
The Next FOG Stop formulation, which comprises proteins from yeast fermentation, together with surfactants and adjuvants, fully satisfied the requirements of Resolution 357 for Class 4 rivers, achieving dissolved oxygen (DO) with an average of 5.0mg/l.
Non-toxic product Previously, bioremediation technologies had been tried for the Pinheiros River, but the results from hybrid enzymes and bacteria proved too inconsistent. However, as a non-toxic and environmentally compatible product, Next FOG Stop strengthens the metabolism of native bacteria, increasing respiration and nutrient uptake and converting much of this energy into carbon dioxide instead of increasing the biomass.
Testing details Tested by an accredited laboratory, the parameters included: Total Solids, Volatile Suspended Solids, Total Suspended Solids, Settled (sediment) Solids, Phosphorus, Total Organic Carbon, Total Nitrogen, Nitrogen ammonia, nitrite, Escherichia coli, Surfactant, and sulfide toxicity (Microtox).
At the end of a 30-day period, assessment of the level of siltation of the canal was performed using analysis of total solids (TS). With the results averaged and the area of the experimental channel known, the results were used to calculate the amount of solids that remained in the system.
Water temperature was one of the most important characteristics in the control of the parameters being monitored and the experimental channel was maintained at an average temperature of 23.5° C. For pH, results in the range from 7.51 to 7.81 were in the optimal range required in CONAMA 357 for Class 4 rivers of pH 6.0 to pH 9.
The water collected from the Pinheiros River which was used to feed into the experimental channels showed dissolved oxygen (DO) near 0 mg/l in almost every test period, rising to 1.00 mg/l only twice.
With the application of FOG Stop, an average of 5.00 mg/l of DO not only resulted in compliance with the legislation but achieved an increase of over 200% above the regulatory requirement.
