Major challenges
• Rapid development and maintenance of MLSS under low organic load
• Complete odour control
• Achieving PCB discharged norms
• Fully operational STP under low availability of sewage.

Situation analysis
Two major problems affecting overall system performance were:

Nutrient scarcity (sub-para)
Like human beings, bacteria need food to survive. Lack of availability of food within the biological system was hindering the growth and development of microbes. As a consequence, desired MLSS level was not achieved and maintained. Microbes need carbon, nitrogen and phosphorous in proper proportion for survival, growth and multiplication. The sewage majorly had nitrogenous load (nBOD) compared to carbonaceous load (cBOD) hence addition of jaggery was suggested into the biological system to supplement carbon demands respectively.

pH (sub-para)
pH plays a pivotal role in growth and development of bacteria and other life forms present in the sewage. Microbes grow optimally at neutral pH (pH 7). The raw sewage had a pH of 9 – 10, which was again hindering biomass development. Therefore, addition of citrate was suggested to lower the pH, as unlike other acids, citrate doesn’t
affect microbial growth and multiplication rather
it boosts their growth by acting as a carbon source in the medium.

CleanMaxx – the economical biotech solution
Since several decades, biological treatment has proven to be an eco-friendly and economical approach to degrade variety of organic pollutants. But the efficiency of this treatment majorly depends upon the beneficial microbes present in the system.

CleanMaxx – a consortium of beneficial microbes – has superior strains of non-genetically engineered and robust microbes rather than a single strain, thereby making it more suitable for surviving under varied temperature and fluctuating organic load. This helps in faster commissioning of biological systems. The microbes are micro-encapsulated to provide better shelf life.
CleanMaxx NT is a third food source of nutrient. This is especially formulated to boost microbial development under stringent conditions.

Approach (para)
• The aeration tank was completely filled with 40 KL of raw sewage.
• Recommended quantity of CleanMaxx and CleanMaxx NT was added to the aeration tank.
• Minimal dosage of citrate was added to neutralise pH.
• The system was provided aeration on continuous basis.
• Microscopic analysis was carried out at intervals to monitor the microbial activity.

Lab analysis reports after start of treatment
Biocheck1 study on the aeration tank sample was carried out on regular basis at our in-house R&D facility.

Results
MLSS development: MLSS analysis was carried out on a regular basis along with COD and BOD analysis to check the development of biomass. The implementation team observed significant improvement in terms of growth within 15 days from the time of commissioning. On the 15th day of the study, MLSS was found to be in the range of 1,000-1,200 mg/litres. By the end of the project, desired MLSS 2,000-3,000 mg/litres and MLVSS of 1,500-2,000 mg/ litres were achieved. This shows that the ratio of MLVSS: MLSS was 0.66, which indicates the optimum desired parameter.

Odour removal: Foul odour resulting from urine in the effluent created a nuisance for the treatment plant. Wastewater odour is most often associated with sulphide and ammonia. Organica Biotech’s microbial technology comprises of several effective strains that do not cause putrefaction during the degradation process. Also these microbes enhance the rate at which ammonia is converted into nitrite and subsequently into nitrate, eliminating the release of ammonia gas. Significant reduction in odour was noticed within 7 days and odour was completely eliminated within 15 days of CleanMaxx addition.

Conclusion
• The biological system of STP was successfully commissioned within 30 days of start of CleanMaxx and CleanMaxx NT addition.
• 100 per cent foaming and odour eliminated.
• Desired biomass levels for proper functioning of the biological system were achieved and maintained consistently.
• Average COD and BOD levels of the treated sewage were below 55 ppm and 7 ppm respectively, which are within the PCB prescribed limits.