MARGAO
The Goa Waste Management Corporation (GWMC) has recommended the setting up of three 5TPD pre-fabricated bio-digesters at Sonsodo in phase I considering the space/area available constraint and increasing daily waste generated in the commercial capital every day.
In the action plan submitted to the Margao Municipal Council, the GWMC has recommended the pre-fabricated bio-digesters over bio-digesters with RCC tanks as it might require 12 months for the RCC tanks to take shape after completing the laid-down tendering process.
While the action plan has cast responsibility on the MMC to construct a shed admeasuring 2000 square meters to set up the integrated dry waste facility for the handling of 25 TPD dry waste, it envisages setting up of three 5TPD pre-fabricated bio-methanation plants at Sonsodo in order to treat the balance quantity of wet waste.
That’s not all. The MMC will be required to finalize specifications for the bio-methanation plants and handholding in procuring from GeM portal, besides construction of shed of about 2000 sq mtrs for accommodating modular bio-methanation plants.
While saying that bio-methanation tanks can be constructed of RCC or pre-fabricated metal tanks, the report says advantages of modular bio-methanation plant over RCC modular bio-digester are pre-fabricated and available on GeM portal and that the time required to set up the facility is comparatively less.
Moreover, the report says that the modular bio-digester can be shifted from one place to another as per the requirement and that it allows easier maintenance in case of breakdown.
“Each modular bio-digester can be taken for periodic maintenance individually, thereby not affecting the treatment process at large. Instead of setting up one major RCC bio-digester, a series of small modular bio-digesters can be installed. Due to modularity the layout of the bio-digesters can be changed as per available area even post-installation and commissioning,” the report stated.
On the bio-methanation plant execution in phase I, the report states that the organic waste after manual segregation shall be fed to the pulveriser/homogenizer where the material shall get homogenized and shredded.
“The waste is further fed into the AD (anaerobic digestion) unit. The continuous high solid thermophilic anaerobic digestion unit (prefabricated containerized) is provided with recirculation. During the anaerobic digestion process, the material passes through the AD unit. The digested residue is extracted from the AD unit from the bottom,” the report states.
It further states that the bio-gas generated through the
bio-methanation process will be passed through H2S scrubber and will be further converted into electricity through bio-gas engine.
The phase II speaks of setting up 20 TPD bio-methanation plant, saying that considering the operations of the modular bio-methanation plant, MMC can consider setting up of an additional four 5TPD modular bio-methanation plants in the existing shed.
The report says that the MMC should explore the possibility of laying a leachate disposal line to be connected to the main sewerage system to dispose of the leachate from the bio-digesters. Till such time the line is laid, the report mandates the MMC to continue transporting leachate generated to government STP at Navelim.
The report further speaks of avenue plantation of trees along the plot boundary and along the roads to give good aesthetic value.
The report will now be placed before the Margao Municipal Council meeting for discussions and to arrive at an appropriate decision.
