Superabsorbent polymers in slurry gelling

Luiza Fernanda Dos Santos Pereira,Paulo Fortes Neto,Marcos Roberto Furlan

doi:10.4136/ambi-agua.2533

Abstract

Disposal of solid waste in landfills causes negative impacts on the environment, caused by emissions of greenhouse gases and the release of dark-colored leachate. It’s composition includes high concentrations of suspended solids, heavy metals, salts and organic compounds. Given the above, this study evaluated the use of superabsorbent polymer in the treatment of leachate. Slurry samples were collected at the Taubaté landfill in two seasons to determine electrical conductivity, pH, turbidity, oils and greases. Other samples were submitted to the following treatments: 3.5 g of polymer with 500 g of distilled water, and doses of 3.5; 7.0; 10.5; 14.0; 17.5; 21.0; 24.5; and 28.0 g of polymer with 500 g of slurry, with 4 repetitions each. Other steps, in sequence, were: transformation of the material into gel (gelation), obtaining the liquid volume of water and slurry, and after 0, 12, 24, 48 and 72 h, measurements of polymer dehydration were obtained. The efficiency of doses was determined by the volume of leachate remaining after each treatment. Gelation was more efficient in the summer season, a season with lower values of electrical conductivity, pH, suspended solids, and oils and greases. The most efficient doses in gelation were 10.5 g in summer and 14.0 g in autumn. In conclusion, superabsorbent polymer can be used in the treatment of leachate because it allows its gelling, but the recommended doses vary with the seasons.

Highlights

The disposal of solid waste in landfills, especially when it is done improperly, causes contamination of surface and underground sources
Leachate originated from water percolation through decomposing waste presents extremely variable composition, and may contain high concentrations of suspended solids, heavy metals, and organic compounds (Cordeiro et al, 2018)
As the amount of leachate generated in a landfill is proportional to the frequency of rainfall, its chemical composition may vary depending on the intensity of rainfall that occurs during the year

Summary

INTRODUCTION

The disposal of solid waste in landfills, especially when it is done improperly, causes contamination of surface and underground sources. Even with the negative impacts on the environment, Conte et al (2018) noted that landfill disposal is still common worldwide This leachate has high polluting potential, and through runoff or percolation causes soil contamination, surface, and groundwater (Pereira et al, 2013). One of the possible options for slurry treatment, still little studied, is the use of polymers The use of these products to treat slurry can be justified by their ability to absorb and retain a large amount of liquid without dissolving. These polymers can have a water absorption of up to 5000 times their own weight in an aqueous medium. It was important to compare the physical and chemical characteristics of the leachate in the two analyzed seasons to verify if the polymer dose is influenced by this climatic variable

MATERIAL AND METHODS

Test performed on samples collected in the summer

CONCLUSIONS