UASBR: An Effective Wastewater Treatment Option to Curb Greenhouse Gas Emissions - Management of Natural Resources in a Changing Environment - page 121

The upflow anaerobic sludge blanket process is one of the most commonly used
wastewater treatment system, with several installations treating industrial waste-
water (Techobanoglous et al. 2004 ).
Ion exchange resins consist of a polymeric matrix and a functional group with a
mobile ion. The most common synthetic structures are: cross linked polystyrene,
cross linked polymethacrylate, phenol-formaldehyde etc. The manufacture of ion
exchange resins involve the preparation of a cross linked copolymer followed by
sulfonation in the case of strong acid cation resins, or chloromethylation and ami-
nation of the copolymer for anion resins (Dow 2000 ). The production process
involves use of variety of chemicals like styrene, divenyl benzene, ethylene glycol
dimethacrylate, isobutyl alcohol, formaldehyde, methanol, ethylene dichloride, tri-
methyl amine, dimethyl amine, methacrylates, polyvinyl alcohol, oleum, etc. The
unused solvents and chemicals make the effluent from the manufacturing process
high in organics, total dissolved solids, and low in pH. The presence of different
chemicals in the wastewater makes the treatment challenging and requires a cost
effective as well as robust process with minimum GHG emissions to meet the
international commitments.
The objective of the work was to study the anaerobic treatability and possibility
of utilizing UASBR in order to optimize the operational cost, reduce green house
gas emissions and convert waste into useful end products.
Methodology
Pilot Scale Digester
The UASB reactor was constructed from MS-FRP sheet with 2 m length, 1 m width
and 4 m height. The working volume of the reactor was 7 m 3 (Fig. 1 ). Sampling
ports were provided for the collection of samples. A centrifugal pump (Grundfos,
Chiu)ofcapacity5m 3 /h was used for feeding wastewater into the reactor. A HDPE
tank of 500 L capacity was utilized as buffer tank.
Seed and Inoculation
The reactor was initially seeded with inoculum from an anaerobically digested
sludge of a sewage treatment plant. On subsequent days, jaggery solution along
with urea and DAP was added to obtain the desired mixed liquor suspended solids
(MLSS) and mixed liquor volatile suspended solids (MLVSS) in the reactor. After
achieving 4 % MLSS and 0.75 MLVSS/MLSS ratio, effluent injection at the rate
of 0.5 m 3 /day started for acclimatization of the micro organisms. The acclimation
period in this study was 60 days.