Abstract
This paper aims to demonstrate the benefits of using a natural coagulant to enhance gravitational sedimentation of pig slurry. The separation process would lead to a liquid fraction, more biodegradable and with lower nutrient content, and a solid fraction highly concentrated in organic matter. Experimental trials were conducted in order to achieve the following objectives: (i) compare the effect of gravitational sedimentation with coagulation–flocculation process, (ii) compare the efficiency of conventional coagulants (such as aluminium sulphate or ferric chloride) with chitosan biopolymer and (iii) test the optimum coagulation–flocculation operational conditions to slurry sample. Assessment criteria included removal efficiencies but also took into consideration the advantages/disadvantages regarding sludge management. Results showed that gravitational sedimentation process can be improved by addition of coagulants; turbidity and COD removal increased around 2 and 3 times, respectively.
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The authors wish to thank Domingos Figueiredo for his support during the analytical procedures.
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Fragoso, R.A., Duarte, E.A. & Paiva, J. Contribution of Coagulation–Flocculation Process for a More Sustainable Pig Slurry Management. Water Air Soil Pollut 226, 131 (2015). https://doi.org/10.1007/s11270-015-2388-4
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DOI: https://doi.org/10.1007/s11270-015-2388-4