Potato Processing Wastewater Treatment Using a Combined Process of Chemical Coagulation and Membrane Filtration

The potato-processing wastewater (PPW) treatment method employe a combined process of chemical coagulation/flocculation and membrane filtration. Four different inorganic coagulants are used: polyaluminium chloride, alum, iron(III) chloride and iron(II) sulphate. The results show that the inorganic coagulants enhanced both chemical oxygen demand (COD) with turbidity removal at 1 g/L of concentration. Iron(III) chloride is the most efficient for COD and turbidity removal efficiencies of 54% and 88%, respectively. At pH=6, COD and turbidity elimination performances are enhanced to 67% and 96%, respectively. The findings suggest that coagulation plays a key role in the removal of COD and turbidity of PPW, but water quality is again improved by a second stage of treatment. The utilisation of ultrafiltration (UP150) at 1 bar of transmembrane pressure (TMP) has highly improved water quality. At the end of this research, a comparative study is conducted between the combined process: coagulation/flocculation-membrane filtration and direct filtration of raw PPW. The results demonstrate that the primary stage of treatment is necessary to prevent early membrane fouling and provided high permeate flux. Even though, the most used treatments rely on combined coagulation/flocculation and membrane filtration systems, very few research articles are reported for PPW treatment.

Automated summary

The study demonstrates that a combined process of inorganic coagulation and membrane filtration is effective in removing COD and turbidity from potato-processing wastewater, with iron(III) chloride showing the highest efficiency, especially at pH=6. Chemical coagulation plays a key role in the removal of COD and turbidity, while membrane filtration further improves water quality.