RESUMEN

Anaerobically-treated palm oil mill effluent (POME) still has unacceptable properties for water recycling and reuse, with an unpleasant appearance due to the brownish color caused by tannins and phenolic compounds. This study proposes an approach for treating anaerobically-treated POME for water recycling by combining organic precipitation, electrocoagulation (EC), and ion-exchange resin, followed by reverse osmosis (RO) membrane filtration in series. The results indicated that the organic precipitation enhanced the efficiency of EC treatment in reducing the concentrations of tannins, color, and chemical oxygen demand (COD) of the anaerobically-treated POME effluent, with reductions of 95.73%, 96.31%, and 93.96% for tannin, color, and COD, respectively. Moreover, organic precipitation affected the effectiveness of Ca2+ and Mg2+ ion removal using ion exchange resin and RO membrane filtration. Without prior organic precipitation, the ion-exchange resin process required a longer contact time, and the RO membrane filtration treatment was hardly effective in removing total dissolved solids (TDS). The combined process gave a water quality that meets the criteria set by the Thailand Ministry of Industry for industrial boiler use (COD 88 mg/L, TDS <0.001 mg/L, water hardness <5 mg-CaCO3/L, and pH 6.9).

Asunto(s)

Filtración , Resinas de Intercambio Iónico , Ósmosis , Aceite de Palma , Eliminación de Residuos Líquidos , Aceite de Palma/química , Filtración/métodos , Resinas de Intercambio Iónico/química , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/análisis , Membranas Artificiales , Purificación del Agua/métodos , Electrocoagulación/métodos , Anaerobiosis , Residuos Industriales/análisis , Análisis de la Demanda Biológica de Oxígeno , Taninos/química , Taninos/análisis , Precipitación Química , Aguas Residuales/química

RESUMEN

Despite the significant removal of chemical oxygen demand (COD) by anaerobic digestion, anaerobically-treated palm oil mill effluent (POME) still contains tannins and other phenolic compounds, resulting in residual COD and a brownish color. In this study, we investigated the removal of tannins from anaerobically treated POME using protein-tannin complexation in conjunction with electrocoagulation. The amino acid composition of the protein, aqueous pH, and protein: tannin ratios were found to be important parameters affecting the tannin removal efficiency. Pig blood protein was superior to casein protein in removing tannins, possibly because it had aspartic acid as the major amino acid component. At an optimal condition with a pig blood protein: tannin ratio of 0.33 (w/w), a current density of 30 mA/cm2, pH 5, and an electrolysis time of 10 min, the removals of tannins, COD, and color were 93%, 96%, and 97%, respectively.

Asunto(s)

Aceites de Plantas , Taninos , Animales , Porcinos , Aceite de Palma , Aceites de Plantas/química , Eliminación de Residuos Líquidos/métodos , Residuos Industriales/análisis , Electrocoagulación/métodos , Aminoácidos

RESUMEN

Thermoanaerobacterium sp. strain PSU-2 was isolated from thermophilic hydrogen producing reactor and subjected to draft genome sequencing on 454 pyrosequencing and annotated on RAST. The draft genome sequence of strain PSU-2 contains 2,552,497 bases with an estimated G + C content of 35.2%, 2555 CDS, 8 rRNAs and 57 tRNAs. The strain had a number of genes responsible for carbohydrates metabolic, amino acids and derivatives, and protein metabolism of 17.7%, 14.39% and 9.81%, respectively. Strain PSU-2 also had gene responsible for hydrogen biosynthesis as well as the genes related to Ni-Fe hydrogenase. Comparative genomic analysis indicates strain PSU-2 shares about 94% genome sequence similarity with Thermoanaerobacterium xylanolyticum LX-11. The nucleotide sequence of this draft genome was deposited into DDBJ/ENA/GenBank under the accession MSQD00000000.