Comparison of polycaprolactone and starch/polycaprolactone blends as carbon source for biological denitrification

Abstract

The cross-linked starch/polycaprolactone (SPCL10) and starch/polycaprolactone (SPCL12) blends were prepared, characterized and used as carbon source and biofilm support for biological nitrate removal. The results showed that SPCL10 and SPCL12 had similar performance on water absorption (about 21 %) and leaching capacity. FTIR spectra confirmed the cross-linking reaction between starch and PCL. SEM displayed a thermoplastic nature of SPCL10 and SPCL12. These blends could serve as solid carbon source and biofilm support for biological denitrification, and the acclimation time of microbial biofilm on the surfaces of SPCL10, SPCL12 and PCL were about 2 days, 2 days and 16 days, respectively. The average denitrification rates were 0.0216, 0.0154 and 0.0071 mg NO 3 -N/(g h) for SPCL10, SPCL12 and PCL, respectively, and the effluent NO 2 -N concentration was below 1 mg/L at all cases. The phenomenon of ammonia formation was observed, but ammonia concentration was below 0.5 mg/L.

Biodegradable nanocomposites based on starch/polycaprolactone/compatibilizer ternary blends reinforced with natural and organo‐modified montmorillonite

“…Its main advantages are its good processability and high elongation at break, but it has low rigidity and tensile strength, and its cost is too high to be used for packaging applications. A possible solution is to blend PCL with less‐expensive biodegradable polymers such as starch …”

“…A possible solution is to blend PCL with less-expensive biodegradable polymers such as starch. 1 Starch is a natural biodegradable polymer existing in many vegetables as the main energy source. It is inexpensive, but its complex granular structure makes it difficult to process by conventional methods, so it needs to be modified with the addition of a plasticizer applying heat and shear forces.…”

Effect of the maleation of lignosulfonate on the mechanical and thermal properties of lignosulfonate/poly(ε‐caprolactone) blends

“…In the spectrum of the pure PCL, a weak sorption band centered at 3375 cm −1 was assigned to the stretching of low‐concentration hydroxyl chain‐end groups of PCL . The absorptions of asymmetric and symmetric CH stretching vibrations were located at 2944 and 2866 cm −1 , respectively, and the weak bands at 1469 and 1416 cm −1 were also ascribed to CH vibrations, bending for the former and scissoring for the latter . The peak centered at 1728 cm −1 of PCL was ascribed to CO stretching vibrations, which could be divided into two peaks in its second derivative curve (not shown).…”

“…DSC is usually used to obtain thermal behavior information, such as the crystallization temperature ( T c ) and melting temperature ( T m ), and to some extent, changes that can be used to indirectly show interactions between the components in polymer blends . In this study, T c and T m were obtained to evaluate the thermal properties of the lignin on PCL in the blend.…”

“…19,21 The absorptions of asymmetric and symmetric CAH stretching vibrations were located at 2944 and 2866 cm 21 , respectively, and the weak bands at 1469 and 1416 cm 21 were also ascribed to CAH vibrations, bending for the former and scissoring for the latter. 22 The peak centered at 1728 cm 21 of PCL was ascribed to C@O stretching vibrations, which could be divided into two peaks in its second derivative curve (not shown). One peak was associated with the amorphous fraction situated at 1737 cm 21 , and a shoulder at 1720 cm 21 corresponded to the C@O stretching in the crystalline part of PCL; this was consistent with the reported literature.…”