Geobag for fecal sludge drying - Malacca, Malaysia

Site visit done by: Sumit Kumar Gautam, Naveen Kumar, Ridhima Gupta

Date of visit: 9 August, 2017

Location: Malacca, Malaysia
Scale: Community
Material: Polypropylene (non-biodegradable)
Pore size: 600 micron
Implementing Agency: Indah Water Konsortium

Designed Capacity: sludge holding capacities range from 11 m3 to 90 m3
Electricity requirement: nil
Capital cost: INR 17,000- 38,000

Geo bags (non-mechanical technology) are used to dry the fecal sludge from OSS and are suitable for decentralized FS treatment. Fecal sludge is transferred to these geo tubes/bags from the tankers and allowed for the filtration and thereby dewatering. The effluent from geo bags is collected through drains and sent for treatment in STP.

After few days when the capacity of the geo bag is met (depending upon size), the sludge is taken out and is finally disposed in a trenching site.

Summary table of Geobag

Constraint	Geobag	Legend
Land Requirement	+++	+++ High requirement ++ Medium requirement + Low requirement
Energy required for daily operation	+
Shallow groundwater table	++
CAPEX	++
OPEX	++
Skill requirement	+
Reuse Opportunity	+

Source: S. Singh et al. / Environmental Technology & Innovation 7 (2017) 203–218

This technology type has a high land requirement but low energy requirement. However, once the bag is filled to full capacity, it is discarded entirely and cannot be re-used for the next cycle.

It is also to be noted that composting is required for the better quality of sludge after it is taken out of the geo bag.

Geo bags are characterized and made with permeable geo fabrics which have the potential to dewater sludge. This treatment technology is sold by various manufacturers in a tube or bag form and have been used in many countries for the dewatering of sludge from various sources at different scales.

During operation, the geo bag is filled with sludge after which, the free water or effluent drains through the permeable material of the geo bag (typically for a few days depending on the characteristics of the sludge) – kindly refer to diagram below.