Mobile Septage Treatment Unit Developed by Wash Institute, Dindigul District, Tamilnadu to treat the Faecal Sludge instantly

                Mobile Septage Treatment Unit   

Problem Statement: 

    In some cases, treatment plants are so distant that it deters the operators to decant their collected faecal waste due to high fuel/operational costs. Most of the operators do not decant the septage in treatment plants due to non-availability of the same. Many Rural Areas are already suffering the consequences in the form of health ailments and serious pollution of water and soil resources. Presently, in rural areas, truck operators are desludging on-site containment systems and dumping the faecal sludge and septage in drains, water bodies and open areas, causing high level of environmental pollution and health risks.

Scope: 

    As of now there is no on-site treatment products exist in the tamilnadu to treat the effluent of onsite sanitation systems such as septic tanks, WASH Institute has come up with an Innovative product/solution to treat the effluent on the site. As septage extracted from the septic tanks consists of 90-95% liquid and 5-10% solid, treating the liquid on the spot addresses the major challenges related to Faecal Sludge and Septage Management (FSSM). The sludge is collected for secondary treatment.

Innovative Solutions-Mobile Septage Treatment Unit: 

    It is a treatment system installed on the bed of a small truck, which is able to treat the contents of septic tanks. The on-site mobile treatment unit works with the concept of solid-liquid separation, sludge thickening and effluent treatment process. While the liquid is separated from the solid, the effluent passes through the treatment process and disposes the treated effluent. The sludge thickening process helps further in reducing the moisture content in the sludge. The solid sludge is collected in centrifuge, and it later goes for secondary treatment. The operational capacity of the MTU varies from 3000 to 6000 lits/hr.

Advantages of MTU:

1. Capital Investment is lower than the Trucks used by Cesspool Operators

2. The Treated effluent’s characteristics are well below than the existing CPCB norms of wastewater disposal

3. The Operational cost to empty & treat septic tanks (capacity between 3000-5000 litres) works out to be Rs.650/-, which is much lower than the existing market price claimed by the Cesspool Operators.

4.Since the MTU can empty & treat 4-8 tanks in a day (depending on the size of the tank), Operators can empty & treat multiple tanks in a single trip, thereby saving fuel costs and preventing environmental pollution.

Treatment Capacity of MTU: 

    WASH Institute has assembled 4 MTUs of which 3 Units are having a capacity of treating 3000 litres per hour. The 4th Unit can treat up to 6000 litres per hour. All the 4 existing units can together treat 15000 litres per hour. The current design of the MTU can empty & treat up to 95% of the total volume of a septic tank. The remaining 5% (which is thick sludge in nature) is left in the tank as sludge blanket for future growth of pathogens in the septic tank. It may be noted that the MTU is designed to empty & treat septage from sealed septic tank only, not from unsealed septic tank or leach pit. The MTU treats the effluent 100% and sludge gets collected in the centrifuge. On an average, the MTU treats 4-8 septic tanks depending on the storage capacity of the tank. At the end of the day, the sludge collected is taken for secondary treatment to drying beds or existing STPs. WASH Institute is converting the thickened sludge into Briquettes (low-cost replacement for Charcoal).

Capital and Operational Cost:     

    The actual assembling cost of a MTU with the treatment capacity of 3000 litres is Rs.1450000/- and the MTU with the treatment capacity of 6000 litres costs Rs.1650000/-. The Capital cost includes the cost of the Mini Truck as well (The current cost of Mahindra mini truck is around Rs.6,50,000/-. This Cost is an approximate and it will vary according to the installation.

The MTU Unit can be installed for the cluster of village panchayats having Households more than 2000 numbers with septic tanks where the existing FSM facilities is not available in 20 kms ranges.