It will be easier to breathe next to Hussainsagar, a Pollution Control Board report dated May 26 indicated. Dissolved Oxygen (DO), which is an indicator of depleting pollution, ranged between 1.4 mg per litre to 1.7 mg per litre.
This, after NACOF-Hyderabad in association with Kiran P. Kulkarni, a Bangalore-based expert conducted one month of bio-remediation treatment in the lake. Dissolved oxygen content was zero in the first four months of this year. DO levels should ideally be above 4. Apart from DO levels, other indicators of pollution levels in the lake has reduced marginally. From Chemical Oxygen Demand (COD) of 119 the level has gone up by 160 whereas Biological Oxygen Demand (BOD) has reduced drastically from 57 milligram per litre to 28. Ideally BOD should not be above 3. During the next six months lake cleansing process is expected to bring DO, COD and BOD levels to near normal. “Areas which were treated with Effective Microbes.1 solution were Sanjeevaiah Park, Tank Bund road and Lumbini Gardens. Six outlets from where sewerage flows into the lake were targeted. Apart from EM.1 solution we made a unique mixture of Bokashi powder, cow dung and mud balls to treat the sludge,” Mr. Kulkarni told The Hindu. The Bokashi and EM.1 mix has matured microbes which eat away the sludge. Once released into the water, they multiply per day to absorb the waste thereby making the water clearer.
PCB also noted that the lake has turned muddy in colour when compared to slate or black colour which it reflected for years. “The colour shows improvement. In two months time, the lake will become lighter in hue and more pleasant for morning walkers,” Mr. Kulkarni explained adding. “A total of 150 tonnes of waste is there in the bottom, but by this proven technology of detoxification it is possible to restore life in the water. In six months the lake will be healthier and DO level, as per our calculation will be four,” Mr. Kulkarni added.
Bacteria which were introduced into the lake were matured by 78 days. The total amount of suspended solids as per the PCB report reduced by 28 points after the microbes were introduced. PCB is expected to do another analysis in September.