Objective: Clean Highly Polluted Lake with Blue Green Algae and Sewage Pollution Outbreak
Indira park lake gets its water from the Hussainsagar lake. The Hussainsagar lake is highly polluted with industrial and domestic sewage. The same water is bringing in nutrients loaded with BGA. This is leading to a foul smell and reduction in water quality. There is an urgent need to bioremediate this very important lake which caters to thousands of visitors and walkers.
This case study shows how the water quality changed considerably after one week of treatment with a significant reduction in total dissolved solids, nitrates, phosphates, nitrogen, and chemical/biological oxygen demand. The diatom growth grew significantly with a major reduction in the presence of blue green algae.
Indira Park Lake Info
- Area: 18,750 square meters
- Depth: 8 meters
- Volume: 150,000,000 liters
- Daily Inflow: 500,000 Liters
Before: How Lake Appeared on May 13, 2014
- Lake is heavily contaminated with Blue Green Algae (BGA) mainly Microcystis sp.
- BGA is present as a suspension in the water column all over the lake.
- Inlet water coming from Hussain Sagar Lake is also contributing to BGA input.
- Air turbulence is carrying the superficial BGA layer towards the bridge side.
- BGA mat is removed manually on daily basis.
- The moats present around the lake also contain heavy deposition of BGA and duck weed.
- Foul smell is emanating from the lake and also places where lake water is used for horticulture.
Gallery of Blue Green Algae Contamination Before Treatment
During: Weekly Nualgi Ponds Treatments
Lake treatment was started on 5/20/14 with addition of 4 liters of Nualgi Ponds the first week with 2 liters each of the next 3 weeks and applied for 1 month total in the Indira Park Lake as well as inlet water from Hussainsagar Lake.
The additive was poured along the sides of the pond water from a small boat and water samples for testing were collected before each addition. Read the scientific data collected below.
Photographs of Algae Mat Reduction and Increased Water Clarity from the Study
Phytoplankton Analysis
From phytoplankton data blue green algae (BGA) was the dominant phytoplankton type present in the lake before Nualgi addition and Microcystis sp. was the dominant species along with Spirulina sp. but after Nualgi addition. slowly the phytoplankton dominace shifted from BGA to Diatoms.
From this analysis, Nualgi clearly triggered diatom growth and in turn diatoms acted as catalysts in improvement of water quality parameters and reduction of BGA growth.
After: Conclusion of Treatment
Water quality of the pond changed considerably when we look at the change in water quality parameters tested before and one week after treatment a significant reduction in TDS was observed from initial reading of 864 to 474 similarly COD and BOD was also reduced from 350 to 212 and 56 to 14 respectively. Nutrient levels also reduced with nitrate reducing from 1.94 to 0.86 and phosphate reducing from 1.12 to 0.88 and Total kjeldal nitrogen also reduced from 16 to 10 over a period of 7 days after addition of Nualgi.
There is significant improvement in the water quality and decline in the Blue Green Algae after 23 days of testing with 10 liters of Nualgi. This is in spite of daily inflow of water from Hussainsagar that brings in nutrients and BGA. If a higher dose of Nualgi is used regularly and if Hussainsagar is also treated the water quality can be further improved.
