A new name for Stenus absconditus Tang Hu, 2018 (Coleoptera, Staphylinidae).

Stenus absconditus Hu Tang, 2018 was published in our recent paper, and latter Dr. Alfred Francis Newton kindly informed us that the name was preoccupied by Stenus absconditus Puthz 2017. After confirming the information, we propose a new replacement name for this species.

Notes on the Dianous aereus complex with description of a new species (Coleoptera, Staphylinidae).

Dianous pseudaerator Tang and Hu, sp. n., a new species of the Dianous aereus complex from China, is described and illustrated. Male of D. brevicornis Puthz, 2000, is discovered for the first time. New distributional records are reported for D. vietnamensis Puthz, 1980, D. rougemontianus Puthz, 2000, and D. aerator Puthz, 2016.

Notes on the Stenus indubius group with descriptions of four new species from China (Coleoptera, Staphylinidae).

Four new species of the Stenus indubius group from China are described: S. yaoluopingus Hu Tang, sp. n. from Anhui Province, S. lizipingus Hu Tang, sp. n., and S. fuscus Hu Tang, sp. n. from Sichuan Province, and S. absconditus Hu Tang, sp. n. from Guizhou Province. The diagnostic characters of the new species are illustrated and a published key to Chinese species of the group by Puthz, 2017 is modified to include the new species. Additional records of some species of the group are also provided.

[Preparation and Pb2+ Electrosorption Characteristics of Graphene Hydrogels Electrode].

Electrosorption has the advantage of high adsorption capacity and electrode regeneration in the removal of heavy metal ions in water. In this study, graphene hydrogels (GS) were prepared by hydrothermal reduction of graphene oxide (GO) suspensions and the electrode was obtained via compression of GS. Various electrochemical properties of GS were tested. The kinetics and thermodynamics of the electrosorption of Pb2+ on GS electrode and GS electrode reusability were investigated. The results showed excellent capacitive behavior (200.4 F·g-1 at 1 A·g-1) of GS. The electrosorption performance of GS indicated that high voltage was favored for the removal of Pb2+ and the highest removal efficiency reached 96.4% when the voltage value was -1.2 V. The electrosorption capacity for Pb2+ removal was found to be 461.20 mg·g-1, which was twice as high as the saturated adsorption capacity of GS. The GS electrode could regenerate after electrosorption when the voltage value was+1.2 V and the removal efficiency of Pb2+ was still maintained above 95% after electrosorption-desorption for 15 cycles.

[Preparation of NiAl-MMO Films Electrode and Its Capacitive Deionization Property].

Hydrotalcites are not only considered as important absorbents in water treatment and but also widely used as super capacitor materials. In this study, NiAl metal oxide (NiAl-MMO) films, which were the calcined products of hydrotalcite-like compounds, were grown on the surface of a foam nickel by an in-situ growth method using a foam nickel substrate as the nickel source. The prepared NiAl-MMO films electrodes materials had stable electrochemical capability, remarkable electrochemical capacitor, and gave a highest specific capacitance of 667 F x g(-1). The desalination performance of material indicated high voltage and weakly alkaline solution were favored for desalination. A highest desalination efficiency was up to 58.17% when the initial concentration of Cl- was 0.003 mol x L(-1), the voltage value was 1.0 V and pH value was 8. The adsorption saturated electrodes could be rapidly regenerated with a desorption rate of 87.96% by electrodes reversion. This study provides a new choice for desalination in wastewater treatment.

[Photocatalytic Oxidation of p-arsanilic Acid by TiO2].

The p-arsanilic acid (ASA) is an important organoarsenical compound and its removal is more difficult compared to inorganic arsenic, however, little attention has been paid to the removal of ASA in aqueous environment. The influence of P25 on the adsorption of ASA, effect of P25 dosage, pH and illumination intensity on the photo-catalysis, the production analysis and main mechanism of photo-degradation were investigated in this study. The results showed that in the P25 catalysis process, simulated natural light could degrade ASA into As (V) by oxidation. The total As was reduced to about 0.34 mg x L(-1) within 0.5 h under the following condition: the initial concentration of ASA was 2 mg x L(-1) and the dosage of TiO2 was 1 g x L(-1). The result showed that the removal rate of ASA in acidic conditions was much higher than that in alkaline conditions. The optimal strength of light was 68.5 mW x Cm(-2). Hydroxide radical played a major role in photocatalytic oxidation of ASA by P25.

[Enhanced Mitigation of Membrane Fouling by Regulations on Floc Morphology in Electrocoagulation].

In this study, the electro chemical parameters were regulated to control the floc morphology in order to mitigate membrane fouling. The main effects of current density, initial pH and conductivity on the floc characteristics and flux were studied, and the mechanisms of interaction between flocs with different morphology structures and ultrafiltration membranes were analyzed. The results showed that the key to mitigate the membrane fouling by electrocoagulation was to form a loose and porous cake layer on the membrane surface. The electrocoagulation-ultrafiltration (EC-UF) technology could not only effectively mitigate the membrane fouling, but also greatly enhance the water quality of the effluent. By increasing the current density and keeping water quality conditions at neutral pH, the EC-UF technology could maintain a higher flux. Under conditions of j=20 A·m-2, initial pH=7 and initial conductivity=1000 µS·cm-1, the removal rate of humic acid (HA) was 97%, and the normalized specific flux of J/J0 was 81%.

[Comparative Study on Pretreatment Process of Ultrafiltration: Chemical Coagulation and Electrocoagulation].

The ultrafiltration membrane response mechanism and the effect on the membrane fouling under dead end filtration were comparatively investigated in ultrafiltration pretreatment processes using chemical coagulation (CC) and electrocoagulation (EC). The effects of Al3+ dosage on the flux of the membrane,the properties of the floc (particle size, strength coefficient, recovery coefficient, fractal dimension) and the properties of the cake layer were studied. The results showed that taking EC as a pretreatment method, the flocs were stronger and more compact, the cake layer deposited on the surface was porous and higly hydrophilic; while in CC pretreatment, the flocs were loose and had low strength, which would be compacted and crushed easily by the pressure in membrane filtration process, resulting in relatively dense cake layer and low hydrophilicity. Therefore, EC was the most effective pretreatment process to alleviate membrane fouling during operation, which could maintain a flux that was about 5.57% higher than CC.

[Preparation and Pb2 electrosorption characteristics of MnO2/CFP composite electrode].

The morphological structure and electrochemical properties of the electrode materials have direct impact on the electrosorption results. In this paper, Manganese dioxide ( MnO2) was composed on flexible carbon fiber paper ( CFP) via anodic electrodeposition technique to prepare the MnO2/CFP hybrid electrodes. The electrodes materials prepared showed stable electrochemical property, remarkable electrochemical capacitance, and the specific capacitance reached up to 360 F x g(-1). Electrosorption was conducted with this MnO2/CFP hybrid electrode to treat the waste water with an initial Pb2+ concentration of 6 mg x L(-1), and the effects of deposition time, initial pH, and voltage value on the electrosorption were investigated. It was shown that when the electrodeposition time was 500 s and the application of voltage value was 1.0 V, pH = 5.0, the best electroabsorption result was achieved. After 3 h electrosorption, the residual Pb2+ in the solution was lower than 0.01 mg x L(-1), and the removal efficiency could reach 99%. This study provides a new technology option for the removal of heavy metal ions in low concentrations in the waste water.

[Characterization of manganese oxidation by Pseudomonas sp. QJX-1].

A manganese-oxidizing bacteria (QJX-1) was isolated from the soil of a manganese mine. It was identified as Pseudomonas sp. QJX-1 by 16S rDNA sequencing. Experimental results showed that the Pseudomonas sp. QJX-1 has a multi-copper oxidase gene CumA, which is an essential component for manganese oxidation by Pseudomonas sp. Under the condition of low initial inoculum level (D600, 0.020), 5.05 mg x L(-1 Mn2+ could be oxidized by QJX-1 within 48 h with a conversion rate of as high as 99.4%. In comparison with the eutrophic conditions, the oligotrophic condition dramatically increased the biological manganese oxidation rate. Biofilm formation by employing the quartz sand could further improve the oxidation rate of Mn2+. Based on these results, it is speculated that biological manganese oxidation in underground water treatment is comparatively high.

[Influencing factors and mechanism of arsenic removal during the aluminum coagulation process].

Aluminum coagulants are widely used in arsenic (As) removal during the drinking water treatment process. Aluminium chloride (AlCl3) and polyaluminium chloride (PACl) which contains high content of Al13 were used as coagulants. The effects of aluminum species, pH, humic acid (HA) and coexisting anions on arsenic removal were investigated. Results showed that AlCl3 and PACl were almost ineffective in As(II) removal while the As(V) removal efficiency reached almost 100%. pH was an important influencing factor on the arsenic removal efficiency, because pH influenced the distribution of aluminum species during the coagulation process. The efficiency of arsenic removal by aluminum coagulants was positively correlated with the content of Al13 species. HA and some coexisting anions showed negative impact on arsenic removal because of the competitive adsorption. The negative influence of HA was more pronounced at low coagulant dosages. PO4(3-) and F(-) showed marked influence during arsenic removal, but there was no obvious influence when SiO3(2-), CO3(2-) and SO4(2-) coexisted. The present study would be helpful to direct arsenic removal by enhanced coagulation during the drinking water treatment.

[Coagulation behavior of Al13 species].

Coagulation behavior of Al13 species was examined in synthetic water with high alkalinity and high humic acid concentration from viewpoint of the transformation of Al hydrolysis products during the coagulation process. The results indicated that coagulation efficiency of Al coagulants positively correlated with the content of Al13 in the coagulation process. Aluminum chloride (AlCl3) was more effective than polyaluminum chloride (PACI) in removing turbidity and dissolved organic matter in the synthetic water because AlCl3 could not only generate Al13 species but also function as pH control agent in the coagulation process. During coagulation process pH control can improve coagulation process through regulating Al speciation, and AlCl3 benefited most from pH control.