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HUESKER Ltd.
Space2work Warrington
Winwick Quay
WA2 8LT Warrington
United Kingdom

Recent applications of geotextile tubes for sludge and slurry dewatering – Brazil

Abstract

Nowadays one of the main environmental problems is the impact caused by waste, remains, by-products, materials and services. In addition, the residue from water and wastewater treatment plants or a liquid effluent generated during any production process, which damages may only be perceived long time after the inadequate disposal. In order to decrease the occurrence of inadequate disposal and such impacts, in Brazil, the National Environmental Council released in 2005 its 357th resolution, which has set the quality standards for effluents on superficial watercourses and classifies water bodies.

To attain the most recent law, and the new environmental preservation standards, some state and private companies are implementing, with exponential growth, slurry and sludge dewatering systems through geotextile tubes, as it’s only or accessory system. This paper regards some of the Brazilian experience in geotextile dewatering tubes, presenting some applications, such as domestic wastewater, industrial wastewater and water treatment plants.

Conclusion

Geotextile tubes are a feasible solution for dewatering slurries and sludge, from water, wastewater and industrial effluents treatments plants, with high filtration efficiency (Figure 8). The experience indicates that the systems is capable of reducing water content of such residues while containing a great portion of solids.

Cone tests can give good insight about the future geotextile tube performance; in some particular cases the dewatering can be performed without chemical conditioning, the experience shows that this is not the usual procedure for dewatering.

In water treatment plants, the association of organic polymers used as flocculants and geotextile tubes for dewatering can reduce chemical products consumption, environmental impacts due to inadequate disposal of slurries with high concentration of heavy metals.

The chemical conditioning, necessity of a flocculant solution, should be evaluated according to the particle size distribution, nature and percentage of solids present in the residue to be dewatered. This study is of great importance for the performance of the entire dewatering system. The solution used for the chemical conditioning can interact or not with the particles, creating bigger particles that can be retained by the geotextile.