Boron separation by adsorption and flotation with Mg-Al-LDHs and SDBS from aqueous solution

Layered double hydroxides(LDHs)have been shown to be effective adsorbents for boron.However,solid-liquid separation is still a problem when separating boron from industrial radioactive waste liquid.In this research,three types of Mg-Al-LDHs including Mg-Al-LDH(NO_(3)^(-)),Mg-Al-LDH(Cl^(-))and Mg-Al-LDH(SO_(4)^(2-))were applied to adsorb boron,and moreover sodium dodecylbenzenesulfonate(SDBS)was used to float the LDH particles from aqueous solution after boron adsorption.The results showed that 60 min was sufficient for the equilibrium adsorption of the three LDHs.The boron adsorption capacity of three LDHs was determined as follows:Mg-Al-LDH(NO_(3)^(-))>Mg-Al-LDH(Cl^(-))>Mg-Al-LDH(SO_(4)^(2-)),and was 2.0,0.98 and 0.2 mmol·g^(-1),each ranging from 0 to 80 mmol·L^(-1)with the initial boron concentration.The efficiency of boron removal by Mg-Al-LDH(NO_(3)^(-))and SDBS can reach up to 89.7%.Furthermore,the boron flotation mechanism of SDBS and LDHs has been studied,since SDBS as a flotation agent can react with LDHs and penetrate into the interlayer of LDHs in addition to electrostatic attraction.Therefore,LDHs in solution can be floated onto the foam layer to be separated from the solution,and the clarified solution was obtained.The method is simple and promising for boron removal from aqueous solution.

Practice and Features of Neo-Chinese Style in Rural Landscape in Zhejiang Province

Neo-Chinese style is popular nowadays and it is wildly used in rural landscape,with only few theories.Under the background of rural revitalization,this paper discussed practice types and design features of neo-Chinese style in rural landscape.Some typical and famous villages of Ningbo,Quzhou and Lishui cities in Zhejiang Province were chosen as cases in this paper.It is committed to providing some theories,inheriting rural culture and promoting rural revitalization.

Rational design of ZnCdS/TpPa-1-COF heterostructure photocatalyst by strengthening the interface connection in solar hydrogen production reactions

ZnCdS quantum dots(QDs)are highly coveted in photocatalysis research for their exceptional visible-light responses and high light-absorption coefficients.However,their practical application is hindered by their tendency to aggregate,due to having high surface energies.To address this issue,herein,a heterostructure is synthesized by growing ZnCdS QDs with a size of approximately 5 nm onto the surface of a two-dimensional(2D)covalent organic framework(COF),TpPa-1-COF.This approach suppresses the aggregation of the QDs and improves their stability.The ZnCdS/TpPa-1-COF composite exhibited a peak hydrogen evolution rate of 6244.16μmol·g^(-1)·h^(-1),which was 2.89 and 4.18 times greater than that of ZnCdS and TpPa-1-COF,respectively.The zero-dimensional/two-dimensional(0D/2D)heterojunction formed by ZnCdS and TpPa-1-COF generates a strong interfacial force,which is attributed to the intimate contact between the interfaces.Tight connections accelerate charge separation,improve the utilisation of reduced electrons,and reduce the extent of agglomeration of the ZnCdS QDs,thereby resulting in high hydrogen production activity of the composites.Meanwhile,the photocatalytic mechanism is studied using Kelvin probe force microscopy and theoretical calculations.This study offers a novel approach for creating sulfide photocatalysts and is crucial for investigating the potential practical applications of the related photocatalysts.

Urban structure and the risk of influenza A(H1N1) outbreaks in municipal districts

Changsha was one of the most affected areas during the 2009 A(H1N1)influenza pandemic in China.Here,we analyze the spatial–temporal dynamics of the 2009 pandemic across Changsha municipal districts,evaluate the relationship between case incidence and the local urban spatial structure and predict high-risk areas of influenza A(H1N1).We obtained epidemiological data on all cases of influenza A(H1N1)reported across municipal districts in Changsha during period May 2009–December 2010 and data on population density and basic geographic characteristics for 239 primary schools,97 middle schools,347 universities,96 malls and markets,674 business districts and 121 hospitals.Spatial–temporal K functions,proximity models and logistic regression were used to analyze the spatial distribution pattern of influenza A(H1N1)incidence and the association between influenza A(H1N1)cases and spatial risk factors and predict the infection risks.We found that the 2009 influenza A(H1N1)was driven by a transmission wave from the center of the study area to surrounding areas and reported cases increased significantly after September 2009.We also found that the distribution of influenza A(H1N1)cases was associated with population density and the presence of nearest public places,especially universities(OR=10.166).The final predictive risk map based on the multivariate logistic analysis showed high-risk areas concentrated in the center areas of the study area associated with high population density.Our findings support the identification of spatial risk factors and highrisk areas to guide the prioritization of preventive and mitigation efforts against future influenza pandemics.