The potential of zero charge (Epzc) of electrodes can greatly influence the salt removal capacity, charge efficiency and cyclic stability of capacitive deionization (CDI). Thus optimizing the Epzc of CDI electrodes is of great importance. A simple strategy to negatively shift the Epzc of CDI electrodes by modifying commercial activated carbon with quaternized poly (4-vinylpyridine) (AC-QPVP) is reported in this work. The Epzc of the prepared AC-QPVP composite electrode is as negative as -0.745 V vs. Ag/AgCl. Benefiting from the optimized Epzc of electrodes, the asymmetric CDI cell which consists of the AC-QPVP electrode and a nitric acid treated activated carbon (AC-HNO3) electrode exhibits excellent CDI performance. For inverted CDI, the working potential window of the asymmetric CDI cell can reach 1.4 V, and its salt removal capacity can be as high as 9.6 mg/g. For extended voltage CDI, the salt removal capacity of the asymmetric CDI cell at 1.2/-1.2 V is 20.6 mg/g, which is comparable to that of membrane CDI using pristine activated carbon as the electrodes (19.5 mg/g). The present work provides a simple method to prepare highly positively charged CDI electrodes and may pave the way for the development of high-performance CDI cells.

Layered double hydroxides (LDHs) are a class of anionic clay materials. When calcined at a certain temperature range, LDHs decompose into corresponding mixed metal oxides (Ox), which are regarded as promising electrode materials for capacitive deionization (CDI). We have developed a simple yet efficient strategy for in situ assembly of the MgAl-Ox nanosheets on graphene (G). The as-obtained MgAl-Ox/G nanohybrids with numerous channels for the access of anion exhibited high surface area and high electrical conductivity. When used as the anode of CDI cell, MgAl-Ox/ G nanohybrids exhibited excellent cycling stability and high electrosorption capacity due to its the memory effect and oxidation resistant property.

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Efficient removal of lead from aqueous media remains a serious task for public health and environment. Here polyacrylonitrile (PAN) monolith is fabricated by means of thermally induced phase separation (TIPS), a novel method that can be used for the preparation of hierarchically structured monolith without any templates assisted. Three hierarchically structured adsorbents (D-PAN, H-PAN, A-PAN) based on PAN monolith were successfully prepared by reacting with diethylenetriamine (DETA), sodium hydroxide, and hydroxylamine hydrochloride, respectively. The Pb (II) adsorption ability of all modified samples was determined by a series of batch tests. Experimental data illustrated that all samples showed excellent Pb (II) adsorption ability and the maximum adsorption capacity of D-PAN, H-PAN, and A-PAN was 144 mg g-1 , 206 mg g-1 and 242 mg g-1 , respectively. The feasible preparation of

Background Oral microbiome played an important role in maintaining healthy state and might exhibit certain changes under circumstances of diseases. However, current microbiological research using sequencing techniques did not regard dead bacteria as a separate part, causing findings based on subsequent analyses on dynamic equilibrium and functional pathways of microbes somewhat questionable. Since treatment by propidium monoazide (PMA) was able to remove dead bacteria effectively, it would be worth studying how the sequencing results after PMA treatment differed from those focusing on the whole microbiota. Methods Unstimulated whole saliva samples were obtained from 18 healthy people from 3 age groups (children, adults, and the elderly). After removal of dead bacteria by propidium monoazide (PMA), changes in the profile of salivary microbiome were detected using 16S rRNA sequencing technology, and differences among age groups were compared subsequently. Results Dead bacteria accounted for nearly a half of the whole bacteria flora in saliva, while freezing had little effect on the proportion of deaths. After treatment with PMA, the numbers of OTUs reduced by 4.4–14.2%, while the Shannon diversity indices decreased significantly (P < 0.01). Only 35.2% of positive and 6.1% of negative correlations were found to be shared by the whole microbiota and that with dead bacteria removed. Differences in significantly changed OTUs and functional pathways among different age groups were also observed between the group of PMA and the control. Conclusions It was necessary to take the influence of living state of bacteria into account in analytic studies of salivary microbiome.