ganesh 2049
TRANSCRIPT
UASB REACTOR
FOR LEACHATE TREATMENT
IN OKHLA LAND FILL
BY: GANESH KUMAR
10/FET/C(S)/2049
CIVIL – 6B1
Toxicity and treatability of leachate: application of UASB reactor for leachate treatment from Okhla landfill, New Delhi.
WHAT IS UASB ?# upflow anaerobic sludge blanket # Upflow anaerobic sludge blanket (UASB)
technology, normally referred to as UASB reactor, is a form of anaerobic digester that is used in the treatment of wastewater.
The UASB reactor is a methanogenic (methane-producing) digester that evolved from the anaerobic clarigester. A similar but variant technology to UASB is the expanded granular sludge bed (EGSB) digester.
UASB uses an anaerobic process whilst forming a blanket of granular sludge which suspends in the tank. Wastewater flows upwards through the blanket and is processed (degraded) by the anaerobic microorganisms. The upward flow combined with the settling action of gravity suspends the blanket with the aid of flocculants.
Upflow Anaerobic Sludge Blanket (UASB)
upflow anaerobic sludge blanket (UASB) process to treat the leachate from a municipal landfill located in Delhi.
A laboratory scale reactor was operated at an organic loading rate of 3.00 kg chemical oxygen demand (COD)/m(3) d corresponding to a hydraulic retention time (HRT) of 12 h for over 8 months.
The effect of toxicity of leachate, and feed composition on the treatability of leachate was evaluated. Average COD of the leachate, during the study period varied between 8,880 and 66,420 mg/l.
Toxicity of the leachate used during a period of 8 months varied from LC50 1.22 to 12.35 for 96 h. The removal efficiency of soluble COD ranged between 91 and 67% for fresh leachate and decreased drastically from 90 to 35% for old leachate having high toxicity.
The efficiency varied from 81 to 65%. The reactor performed more efficiently for the treatment of fresh leachate (less toxic, LC50 11.64, 12.35, and 12.15 for 96 h) as compared with old leachate (more toxic, LC50 1.22 for 96 h). Toxicity of the leachate affected its treatment potential by the UASB.
Advantages over conventional treatment ::
With UASB the aeration the whole process of settlement and digestion occurs in one or more large tank(s). Only the post UASB liquids, with a much reduced BOD needs to be aerated.
This leads to a halving of the aeration energy and a doubling of the power generated from digestion, leading over all to a tripling of power generated.
Vijaya Singh, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110 016, India
Atul K. Mittal, Indian Institute of Technology Delhi, Huaz Khas, New Delhi, 110 016, India
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