Initiating Biodegradation of Polyvinylpyrrolidone in an Aqueous Aerobic Environment: Technical Note / Zainicjowanie Biodegradacji Poliwinylopirolidonu W Środowisku Wodno-Tlenowym: Notatki Techniczne

Abstract

A synthetic polymer, polyvinylpyrrolidone (PVP -E 1201) primarily finds applications in the pharmaceutical and food industries due to its resistance and zero toxicity to organisms. After ingestion, the substance passes through the organism unchanged. Consequently, it enters the systems of municipal wastewater treatment plants (WWTP) without decomposing biologically during the waste treatment process, nor does it attach (through sorption) to particles of activated sludge to any significant extent, therefore, it passes through the system of a WWTP, which may cause the substance to accumulate in the natural environment. For this reason the paper investigates the potential to initiate aerobic biodegradation of PVP in the presence of activated sludge from a municipal wastewater treatment plant. The following agents were selected as the initiators of the biodegradation process -co-substrates: acrylamide, N-acethylphenylalanine and 1-methyl-2-pyrrolidone, a substance with a similar structure to PVP monomer. The biodegradability of PVP in the presence of co-substrates was evaluated on the basis of biological oxygen demand (BOD) as determined via a MicroOxymax O2/CO2/CH4 respirometer. The total substrate concentration in the suspension equaled 400 mg·dm -3 , with the ratio between PVP and the cosubstrate being 1:1, while the concentration of the dry activated sludge was 500 mg·dm -3 . Even though there was no occurrence of a significant increase in the biodegradation of PVP alone in the presence of a co-substrate, acrylamide appeared to be the most effective type of co-substrate. Nevertheless, a recorded decrease in the slope of biodegradation curves over time may indicate that a process of primary decomposition was underway, which involves the production of metabolites that inhibit activated sludge microorganisms. The resulting products are not identified at this stage of experimentation.

PVP Based Materials: Biodegradation in Different Environments

“…However, practical studies of PVP biodegradation, without any previous modifications of the sample, are almost in line with results indicating that PVP is largely resistant to biological degradation [3][4][5][6].…”

“…The broth corresponded to the medium from soil experiment for aerobic conditions. However, the broth for anaerobic conditions was prepared slightly differently: a 1 dm 3 volumetric flask was filled with 500 cm 3 and 50 cm -3 of (NH 4 ) 2 SO 4 (10 g·dm -3 ) solution was added [3]. At the end, the solution was stirred and the volumetric flask was filled up to the mark with distilled water.…”

“…All tests were performed in triplicate. The biodegradation in percentage (D) was calculated from equation [3]:…”

“…Julinova et al [3] suggested theoretical decomposition of PVP in the presence of specific types of microorganisms. This suggestion is divided in two steps.…”

“…Thus, the aim of this paper is to study the biodegradability of PVP/PLA films based on de Paula's research [18] and the biodegradability of PVP/PLA system with addition of NMP, OP, AC and APhA [3].…”