NINGAN China is a city with 440,000 Population situated in the Northern Province of Heilongjiang. The City is famous for its Ice Sculpture festival and experiencing harsh winter conditions during most of the time of the year.
During the period of 2010, The city was commissioning a BOD removal Sewage Treatment Plant based on Oxidation Ditch Pond Technology for their sewage disposal requirement. However, due to change in the legislation , they required to meet Chinese Class I criteria of BOD,TSS,TN < 15 ppm with Ammonia < 5 ppm . Thus the plant required upgradation to achieve these criteria.
Very low ambient temperatures of -15 to -25 Degree C having liquid temperature in the range of 8-10 Degree C
Already existing STP was under construction and thus utilizing existing infrastructure to its maximum efficiency was a challenge.
Achieving Nitrification under such colder climate through out the year was the biggest challenge authorities were facing.
THE SOLUTION: LEVAPOR-IFAS UPGRADE
Based on Levapor’s extensive experience with Colder Climate Nitrification of Municipal Wastewater, a solution was proposed which required to upgrade the existing Activated Sludge system to Levapor based IFAS Process by adding Levapor carriers at 12-15% filling ratio in the existing Aeration Tank basin.
For the Upgradation of the Sewage Treatment Plant to achieve Nitrification at winter temperatures , following design was suggested.
Winter Liquid temperature
8-10 Degree C
Levapor Media filling
400 m3 ( 12.5% of total Volume)
The plant was started during the month of October 2010 , which is already winter in Northern Province.
Despite start up during winter, the plant achieved remarkable nitrification within 6 weeks time period and remain stable over a wide range of BOD,COD and TKN loads to the plant.
The plant then has been performing well under varying conditions of temperature, BOD/COD/TKN fluctuations meeting Chinese Class I criteria of BOD/TSS/TN < 15 ppm through out the year.
During the year, the plant experience a wide fluctuations in the inlet COD concentrations. However despite this fluctuations in the inlet COD values and liquid temperatures, the plant is consistently meeting COD < 50 ppm in the outlet all the time.
NITRIFICATION AND TKN REMOVAL:
Despite cold winter start up, the Nitrification was established at NINGAN plant with LEVAPOR IFAS Process within 6-8 weeks period and remained stable over a wide range of inlet COD,TKN and temperature conditions.
Throughout the year, the plant is consistently meeting the NH4.N and TN criteria. Due to internal porosity of Levapor carriers, remarkable Simultaneous Nitrification and Denitrification is also occurring in the plant achieving TN values in the outlet without Anoxic Denitrification basin.
THE LEVAPOR-IFAS ADVANTAGE ATNINGAN PLANT
Consistently Meeting Chinese Class I Criteria of BOD/TSS/TN < 15 ppm through out the period of operation Despite lower temperature of 8-10 Degree C, Achieving Stable Nitrification
Achieving COD < 50 ppm and NH4.N < 5 ppm all the times