EFFECT OF FINE BUBBLE AERATION ON WATER QUALITY OF JAMUNA JHEEL, LUCKNOW

Abstract

In our country most of the lakes, Jheels, tanks and reservoirs are suffering from different stress factors especially in urban areas. The eutrophication remains as the main water quality related problem. The way to curb the degradation is to stop the inflow of organic matter, nutrient sources and to accelerate the restoration with help of in-lake technologies. Lucknow, the capital of Uttar Pradesh, sustaining small lake namely Jamuna Jheel is another such examples. The ecology of this Jheel is adversely affected due to the discharge of water treatment plant residuals, non-point municipal sewage discharges, solid and industrial waste released from surrounding areas. In order to restore the quality of the jheel, the Government of Uttar Pradesh is setting up in-lake technologies such as fine bubble tube aeration system. For baseline data collection, comprehensive water quality analysis and biological monitoring is conducted at various locations of jheel. It was observed that average values of Secchi depth ranged below 0.5 m, BOD ranged from 15 mg/L to 70 mg/L, Ammonical nitrogen varied from 3.65 mg/L to 23 mg/L, nitrate-nitrogen ranged between 1.4 mg/L to 11.4 mg/L, DO has reached 2 to 4 mg/L after bubble aeration and Total Phosphorus concentration was greater than 100 p.g/L. Fecal Coliforms values were 1500 MPN/100mL to 4.3 x 107 MPN/100mL. The dominant phytoplankton and zooplanktons species in the jheel were Chlorella sp., Oscillatoria sp., Fragilaria sp., Nitella and Ulothrix sp., Lecane, Rotifers, Epistylis and Leech. In addition, average NSF Water Quality Index (WQI), Biodiversity and Saprobity indices before and after the installation of fine bubble aeration were found to be 45, 50 and 44 respectively and TSI values ranged from 80 to 100 showing eutophic condition of Jheel. Based on the results the most important step would be the complete treatment of all drains falling into the jheel. The introduction of filter feeding herbivore organisms like daphnia and grass scrap could also be an alternative for reducing algal biomass in the Jheel. Since trophic status of Jheel is measured by chlorophyll, secchi depth, total phosphorus, total nitrogen and oxygen depletion which can be decreased with deweeding and bubble aeration installation resulting in decrease in the TP and TN controls biomass (chlorophyll-a) finally improving the status of jheel. Keywords: Limnology, eutrophication, Lake Restoration. iii