Iron Species-Impregnated Granular Activated Carbon as Modified Particle Electrodes Applied in Benzothiazole Adsorption and Electrocatalytic Degradation

The object of this study is to prepare iron species-impregnated granular activated carbon as particle electrodes in order to improve their adsorption and electrocatalytic degradation capacity in Benzothiazole removal.The incorporation of Fe-containing catalysts was performed by Fe(NO_3)_3 impregnation.The obtained samples were characterized by BET,Fourier transform infrared spectroscopy,SEM-EDS,powder X-ray diffraction,X-ray photoelectron spectra and TG.Compared with pure activated carbon,this modified particle electrodes show higher static adsorption capacities and TOC removal,which have respectively increased by25.9% and 54.4%.Both physisorption and chemisorption exist in the process of benzothiazole adsorption,where the latter plays a major role.In this way,the Fe-containing catalysts on modified particle electrodes are demonstrated to make a greater contribution to the improvement of electrocatalytic degradation by decreasing the activated energy by 32%.

Degradation Pathway of Benzothiazole and Microbial Community Structure in Microbial Electrolysis Cells

In this study, benzothiazole was entirely mineralized by an up-flow internal circulation microbial electrolysis reactor. The bioelectrochemical system was operated at ambient temperature under continuous-flow mode. The analysis of metabolite which was extracted by HPLC-MS from the bioreactor indicated that benzothiazole derivative ( BTH ) was firstly converted into 2-hydroxybenzothiazole in the microbial electrolysis cell (MEC) and then mineralized within three steps, i.e., the fracture of thiazole-ring through a series of oxidation and hydrolysis, the deamination and hydroxylation of 2-aminobenzenesulfonic acid, and the mineralization of various carboxylic acids to CO2 and H2O. Bacterial community analysis indicated that the applied electric field could selectively enrich certain species and the dominate bacteria on the electrodes belonged to Proteobacteria, Bacteroidetes, and Firmicutes. Results show that MEC can improve the degradation efficiency of BTH in wastewater, enable the microbiological reactor to satisfy the requirements of high loading rate, thereby fulfilling the scale-up of whole process in the future.

Effect of Co-substrate on Degradation of Benzothiazole in MEC

Due to its persistence and bio-toxicity,benzothiazole(BTH) cannot be biodegraded efficiently.Recent work has shown that removal rates of biorefractory organics can be enhanced by the addition of cosubstrates.In this work,ethanol,acetate,propionate and butyrate were added as co-substrates in order to promote the degradation of BTH in microbial electrolysis cell(MEC).By probing the changes in degradation rates of BTH in the presence of different co-substrates,it was observed that all the four co-substrates can enhance the BTH degradation in MEC,both the efficiency(EBTH) and the rate(RBTH).It was also found that acetate is more effective than others,which made the degradation efficiency of BTH up to 90% with acetate-C at350 mg/L(measuring by the carbon content of co-substrate,the same below),within 6 h and the degradation rate of BTH arrived 0.001 2/(mg·h).The microbacteria in MEC have also been influenced by different cosubstrates.This metabolism of the co-substrates enables the microbacteria on anode to generate ATP and thus grow to ensure the microbacteria activity.Therefore,this work showed that the addition of co-substrates such as acetate can be a novel and efficient approach for improving the elimination of BTH from wastewaters by MEC system.

Genetic study on the behavior of honeybees influenced by polyandry system

Within a honeybee population, due to polyandry, there are super-sister and half-sister relations, thus many sub-families exist. For the Chinese honeybee (Apis cerana cerana F.) a phylogenetic dendrogram has been constructed in which 4 sub-families are clustered based on DNA fingerprint patterns. And it has been observed that each kind of workers is distributed to several different sub-families.