A recent article published on www.pbs.org has highlighted the incredible work that is being undertaken in China on reducing phosphorus concentrations in their lakes. A new study analysed 862 lakes across China and found that between 2006 and 2014, the phosphorus concentration has dropped by 60%. During this time, China has invested US$116 billion towards projects and regulations aimed at curbing water pollution.
The article attributes the excessive phosphorus in lakes from agricultural (fertilizer) runoff; aquaculture runoff; domestic and industrial waste water; and water from the phosphate chemical industry.
According to the article, every 5 years the Chinese Government reviews and revises its national plan to control water pollution. Since 2006, the China State Council and the Ministry of Environmental Protection has issued 34 laws or regulations targeting domestic and industrial wastewater discharges.
Although the Chinese government has significantly reduced the concentration of phosphorus entering Chinese lakes, many of the lakes still suffer from thick blue-green algal blooms. This is because the phosphorus that feeds the algae can also be stored in lake sediments. Over time this stored phosphorus is released and used to feed future blue-green algal blooms. Many lake managers around the world focus on the phosphorus entering the lakes in the runoff or the phosphorus in the water column, however they forget about the large phosphorus sources stored in the lake sediments.
Phoslock is used to bind dissolved phosphorus in the water column and sediments that would otherwise be used by algae. The use of Phoslock in China is a relatively new and emerging market. Over time, Chinese environmental regulators will understand the necessity of significantly reducing the phosphorus concentrations not only in the lake water but also from the sediments. The dual reduction will have a major impact on reducing blue-green algal blooms and significantly improve the current water quality issues in Chinese lakes.
The full article can be found at: http://www.pbs.org/newshour/rundown/chinas-blueprint-clean-lakes-stop-algae-blooms-working/