Degradation of Decabromodiphenyl Ether in an Aerobic Clay Slurry Microcosm Using a Novel Immobilization Technique

Abstract

A novel chitosan immobilization technique that entraps photocatalyst and microbes was developed and applied to decompose decabromodiphenyl ether (BDE-209) in a clay slurry microcosm. The optimized conditions for immobilization were obtained by mixing 1.2% (w/v) chitosan dissolved in 1% (v/v) acetic acid with nano-TiO2 particles and the BDE-209-degrading bacterial mixed culture. This aqueous mixture was injected into 1% (w/v) water solution containing sodium tripolyphosphate to form spherical immobilized beads. The surface of the immobilized beads was reinforced by 0.25% (v/v) glutaraldehyde cross-linking. These beads had enough mechanical strength during BDE-209 degradation to maintain their shape in the system at a stirring rate of 200-rpm, while undergoing continuous 365 nm UVA irradiation. This novel TiO2-Yi-Li immobilized chitosan beads system allowed a successful simultaneous integration of photolysis, photocatalysis and biodegradation to remove BDE-209. The remaining percentage of BDE-209 was 41% after 70 days of degradation using this system. The dominant bacteria in the BDE-209-degrading bacterial mixed culture during remediation were Chitinophaga spp., Methyloversatilis spp., Terrimonas spp. and Pseudomonas spp. These bacteria tolerated the long-term UVA irradiation and high-level free radicals present, while utilizing BDE-209 as their primary carbon resource. This new method has great potential for the treatment of a range of pollutants.

Removal of Phenol by Rhodococcus opacus 1CP after Dormancy: Insight into Enzymes’ Induction, Specificity, and Cells Viability

“…and Pseudomonas spp. decomposed decabromodiphenyl ether, while also demonstrating stability under the conditions of long-term UVA irradiation and the presence of high-level free radicals [ 23 ]. The use of biological preparations is limited by a number of issues, such as maintaining cell viability, maintaining a metabolically active state, and the time required for the cells to resume active growth.…”

Special Issue “Biodegradation and Environmental Microbiomes”: Editorial

“…Microbes in total and their interactions with their dwelling environment and/or host, which is the core concept of microbiomes [ 3 ], are the main driving force for biodegradation and bioremediation of chemically synthesized compounds or natural products generated from malfunctioning ecosystems. This Special Issue “Biodegradation and Environmental Microbiomes” has collected 17 papers [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ] that cover diverse researches in this field of environmental microbiology and bioremediation.…”

“…As the first reader, the editor is happy to read the two reviews [ 4 , 5 ] from Yuan’s lab, a pioneering group of scientists in synthetic biology, that summarize and prospect the state-of-art of biodegradation of plastics, including polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), and polystyrene (PS), and particularly emphasize the great potential of synthetic biology tools for construction of artificial microbial consortia or artificial synthetic microbiomes for the efficient degradation of plastics. This Special Issue also discloses new microbial resources, in addition to the microbial resources summarized in reviews [ 4 , 5 ], that are key to efficient removal of naturally generated but disgusting materials from malfunctioning ecosystems [ 7 , 8 ] or chemically synthesized compounds such as decabromodiphenyl ether [ 10 ], tetracycline [ 13 ], and sulfamethoxazole [ 14 ]. Ma et al [ 8 ] screened out bacterial strains from composting sites for highly efficient deodorization and suppression of the odor gas of pig manure, which has high application value for the control of odor pollution.…”