Attractive Spheres Research Articles

Evaluation of potential adsorbents for simultaneous adsorption of phosphate and ammonium at low concentrations

Evaluation of potential adsorbents to tackle eutrophication caused by low concentrations of phosphate and ammonium are rarely reported in the literature. Besides, the dynamics/mechanisms for removal of these pollutants at low concentration are yet to be explored. In this study we used five different adsorbents, including La-modified zeolite (LMZ), MgFe-modified biochar (MgFe-BC), phoslock, activated alumina (AA), and diatomaceous earth (DE) to evaluate the removal of these pollutants. Among the selected adsorbents in this study, LMZ and AA both exhibited effective and simultaneous adsorption for phosphate and ammonium and the maximum adsorption capacities were 2.47 mg/g and 3.07 mg/g, respectively. The presence of SO42− and CO32− negatively impacted phosphate adsorption, while Fe3+ and K+ ions inhibited ammonium adsorption. LMZ adsorption kinetics was over 3 times faster than other adsorbents within 60 min reaction time. Kinetics studies and isotherms revealed that the removal of phosphate and ammonium was primarily driven by chemical interactions and monolayer adsorption and were better fitted by Langmuir isotherm than the Freundlich isotherm and kinetic study was effectively described by Pseudo-second-order kinetic model. FTIR and XPS analysis revealed that the key mechanisms for phosphate adsorption were electrostatic attraction and inner sphere complexation through ligand exchange, whereas ammonium adsorption was mainly governed by ion exchange. Desorption study revealed that LMZ material was stable after three desorption cycles. This study offers vital knowledge on the nature of adsorption and interactions of potential mesoporous adsorbents with eutrophication-causing pollutants in lakes and rivers and proposes effective remedial mean.

On metallic-type asteroid rotation moving in magnetic field (introducing magnetic second-grade YORP effect)

A novel physical effect has been found to be illuminated of being physically self-consistent to take into account in further calculating the dynamics of magnetically-induced asteroid rotation, surface of which has mostly a conducting structure (whereas such mostly metallic-formed asteroid is assumed to be moving in an external magnetic field of planet but in the meantime to be orbiting preferably outside its sphere of effective attraction). The last condition of asteroid surface's having conducting structure means the existence of the applied external torques stemming from the physical interactions between external magnetic field and iron asteroid itself (including long-term effect due to torques stemming from arising eddy-currents on metallic surface of asteroid). Such eddy-currents should heat the conducting surface of asteroid with further non-uniformly re-directing the heat flow from surface of asteroid into outer space via fluxes of thermal photons which carry momentum (in orthogonal direction to the surface which is in most cases far from the ideal surface of sphere). This leads by taking into account the overall outcome of heat flow (from the non-ideal surface of asteroid) to a kind of long-term magnetic second-grade YORP effect. System of Euler equations for aforementioned dynamics of asteroid magnetic rotation has been investigated in regard to existence of semi-analytical solution. Various perturbations (such as collisions, YORP effect) may destabilize the rotation of asteroid deviating it from the current spin state, whereas the electric(eddy)current-induced dissipation of energy reduces kinetic one of asteroid spin. So, dynamics of the asteroid rotation should result in a spinning about maximal-inertia axis with the proper spin state corresponding to minimal energy with a fixed angular momentum.

Theoretical study of kinetic arrest, shear elastic modulus, and yielding in simple biphasic colloidal mixtures.

Based on integrating microscopic statistical mechanical theories for structure and ideal kinetic arrest at the naive mode coupling level, we study dynamic localization, the linear elastic shear modulus, applied stress induced modulus softening, and the absolute yielding of simple biphasic binary mixtures composed of equal diameter hard and attractive spheres. The kinetic arrest map is a rich function of total packing fraction, strength of attraction, and mixture composition. The gel to attractive ideal glass transition, the degree of glass melting re-entrancy, and the crossover boundary separating repulsive glasses from attractive glasses vary with the mixture composition. Exponential and/or apparent (high) power law dependences of the elastic shear modulus on the total packing fraction are predicted with effective exponents or exponential prefactors that are sensitive to mixture composition and location in the kinetic arrest map. An analysis of the effective mean square force on a tagged particle that induces dynamic localization reveals a compensation effect between structural correlations and degree of particle localization, resulting in the emergence of a weaker dependence of the shear modulus on mixture composition at very high attraction strengths. Based on a microrheologically inspired formulation of how external stress weakens particle localization and the shear modulus, we analyze mechanical-induced modulus softening and absolute yielding, defined as a discontinuous solid-to-fluid stress-induced transition that can occur in either one or two steps. Estimates of the corresponding yield strains predict that the binary mixture becomes more brittle with increasing sticky particle composition and/or attraction strength.

ДОСВІД ІЗРАЇЛЮ З РОЗВИТКУ ІННОВАЦІЙ ТА ТУРИЗМУ В УМОВАХ ВОЄННИХ ДІЙ

The experience of Israel in the development of innovations and tourism in the conditions of military operations is considered. The indicators of the innovative activity of the country according to various global ratings are analyzed. The factors that contribute to the successful formation of Israel's innovation ecosystem, which integrates education, science, business and the state, are identified. Considered successful cases of innovative activity of the defence complex of Israel, which today is the main employer of the country and the sphere of attraction of investments. Attention is drawn to the system of assimilation, the transfer of advanced developments carried out by order of the military department to the civilian sphere, the involvement of teams of researchers and developers to develop products for non-military markets and, more often, to adapt defence technologies for civilian applications. The role in the development of the innovation ecosystem of the military departments of innovation and technology development, which attract significant investments, build incubators and accelerators for the creation and development of military innovative developments, was noted. Emphasis was placed on the need to borrow the experience of forming a system of support for innovative ideas and creating conditions for their implementation for military personnel after the end of service. It was noted that the priority for Israeli society and the state is human life at all stages, caring for it. This is laid in the basis of national security, permeates all spheres of Israeli state policy. The elements of the Israeli start-up ecosystem, which allow to support ambitious projects in the field of tourism in the conditions of military conflicts, have been studied. It is emphasized that it is the lost benefits (revenues not received and tourists who refused to travel), and not military budgets, that determine the main economic losses of tourism from the war. It was noted that Israel actively promotes the safety of most of its territories, involving other countries, which today does not make Ukraine and its tourist offices relatively safe regions. Individual start-ups in the field of tourism that offer applications, platforms, services that help in various aspects of travel, staying in hotels, planning routes, etc. are considered. It is concluded that Israel is currently the country with the greatest potential for innovation in the high-tech sector and the tourism space, thanks to an effective technological start-up ecosystem. Israel demonstrates the highest level of flexibility: the country cannot actively restore its own tourism, but it successfully offers technological solutions to the global tourism industry through a start-up ecosystem. It is completely impossible to copy the Israeli system of support for innovations, start-ups, tourism, Ukraine, and other states. However, Israel's experience in attracting funding from abroad and private investment, supporting R&D, applied research, stimulating youth to innovation and creativity, supporting the education of military personnel, creating territorial centres for the support of knowledge and innovation, creating a comfortable environment for the exchange of experience and technologies, development of tourism in a country with constant military conflicts is worth studying and adapting.

Estimating the abundance of benthic invertebrates from trap-catch data

Abstract Trap fisheries targeting invertebrates are economically important but many of the target species lack stock assessments. One reason for this is the difficulty of estimating density. One important means by which density can be estimated uses the catch rates of baited traps that are spaced at different distances. With declining spacing, the sphere of attraction will increasingly overlap, leading to reductions in catches, allowing for the estimation of the density that is catchable by traps on the seabed. Here we review the analytical methods adopted across a range of studies and find that no consensus on robust methods exists. We propose an analytical method that assumes the trapping area is circular and that the chance of catching an individual declines linearly with distance from the trap. We apply this method to estimate the density and the trapping radius of crabs and gastropods from real and simulated datasets. The method estimated a trapping radius of between 4 and 86 m, and densities that are up to 2.5 times less and 13 times greater than estimates provided in the original sources, illustrating the sensitivity to methodology. In conclusion, we provide and test a standardized method to estimate the density of benthic invertebrates.

ЧЕМАЛ КАК ЦЕНТР ЭТНОКОНФЕССИОНАЛЬНОГО ТУРИЗМА В РЕСПУБЛИКЕ АЛТАЙ

The promising "Big Altai Program" is being developed in the south of Western Siberia. The concept of "Big Altai" covers the regions unique for tourism – Gorny Altai ( the Altai Republic) Rudny Altai (Altai Territory), Sayano-Altai (the Republic of Khakassia and the Republic of Tyva), Gobi Altai and Mongolian Altai (Mongolia). Based on the collected information, the development of ethnological-confessional tourism in the Altai Republic is highlighted by the author. In modern conditions of globalization, it takes place the unification and commercialization of ethnic culture of the Altaians (the titular ethnic group of the republic), Russians ( the ethnic majority of the region), and Kazakhs as a local large diaspora. In changing tendencies of the Russian society development, there is a belief that through ethnic tourism it is possible to return to ancient national traditions. For the local population and specialists involved in tourism services, it is an active factor of regional development, a source of employment. For the guests, ethnological-confessional tourism represents both an attractive sphere of communication and a direct entry into an unknown and little-known culture. According to the archival materials by the collector A.V.Anokhin, referring to the beginning of the last century and stored in the Peter the Great Museum of Anthropology and Ethnography (Kunstkamera) in St. Petersburg, the Altai regional tourism has a 100-year history. In the XIX century, the Altai Spiritual Mission was founded in the village of Chemal, which now-days has become the center of modern ethnological-confessional tourism in the region. In 2000, the Church of St. John the Theologian was restored on the Patmos rock near the Katun River, which became an Orthodox shrine that attracts tourists. The island of Patmos is associated with two priests by name of Makarius who served in the Chemal camp at different times. The locals called the island Makarievsky, since Father Makarius (Glukharev), the founder of the camp, was the first; and later, in 1916, there served Father Makarius (Nevsky). The history of the village of Chemal determined the restoration of Orthodox shrines, turning this village into a center of ethnological-confessional tourism in the Altai Republic.

Shear induced tuning and memory effects in colloidal gels of rods and spheres.

Shear history plays an important role in determining the linear and nonlinear rheological response of colloidal gels and can be used for tuning their structure and flow properties. Increasing the colloidal particle aspect ratio lowers the critical volume fraction for gelation due to an increase in the particle excluded volume. Using a combination of rheology and confocal microscopy, we investigate the effect of steady and oscillatory preshear history on the structure and rheology of colloidal gels formed by silica spheres and rods of length L and diameter D (L/D = 10) dispersed in 11 M CsCl solution. We use a non-dimensional Mason number, Mn (=Fvisc./Fattr.), to compare the effect of steady and oscillatory preshear on gel viscoelasticity. We show that after preshearing at intermediate Mn, attractive sphere gel exhibits strengthening, whereas attractive rod gel exhibits weakening. Rheo-imaging of gels of attractive rods shows that at intermediate Mn, oscillatory preshear induces large compact rod clusters in the gel microstructure, compared to steady preshear. Our study highlights the impact of particle shape on gel structuring under flow and viscoelasticity after shear cessation.

РЕФОРМИРОВАНИЕ СФЕРЫ ВЫСШЕГО ОБРАЗОВАНИЯ В РОССИИ: ГЕНЕЗИС, ОСОБЕННОСТИ И ВЛИЯНИЕ НА СОЦИАЛЬНО-ТРУДОВЫЕ ОТНОШЕНИЯ В ВУЗЕ

The main stages, directions, and programs of reforming the sphere of higher education in Russia and their impact on changing the system of social and labor relations in universities are discussed in this article. The characteristic of the main categories of the institutions of higher education is given: the goals of creation, similarities and differences, the role of implementation programs of academic leadership. The authors have highlighted the features of social and labor relations in the organizations of higher education: in the sphere of attraction, employment, organization, and motivation of scientific and pedagogical workers.

Matrix models of portfolio analysis as a tool for choosing an organization's growth strategy

Subject. The article addresses matrix models of portfolio analysis as a tool to select a strategy for organizational growth. Objectives. The focus is to review the existing matrix models for portfolio analysis of strategic management at the level of business units. Methods. The study draws on general scientific methods of analysis. Results. The paper provides the features of the construction of described matrices, possible limitations and advantages of using specific models, and gives recommendations for their use to define prospects for corporation development in target markets. I show that there is no unambiguous algorithm for using a specific model in a certain situation, and the choice of a tool for portfolio analysis rests on many factors that are unique to each particular case, given organizational capabilities and resources of the corporation. Conclusions. The advantage of matrix models is their visibility. They reflect the fundamental points of strategic management, indicating areas of investment in attractive spheres, where the company has the strongest competitive positions. They are an effective tool of strategic management to make management decisions on company's position in the market.

Assessment of the economic attractiveness of the spheres of economic activity of small enterprises according to statistical survey data

The subject of the study is the economic attractiveness of the spheres of economic activity, which are considered in the article in the context of sections of the current classification of types of economic activity, while each section corresponds to a certain enlarged sphere. the purpose of the work is to assess the economic attractiveness of the spheres of economic activity of small enterprises according to statistical survey data. The paper verifies the scientific hypothesis that, based on official state statistics, it is possible to get an idea of the economic attractiveness of individual spheres of activity of small enterprises and, by comparing them with each other, to build a generalized rating of groups of economic sectors according to their attractiveness for small and micro enterprises. The article summarizes the definitions of economic and entrepreneurial attractiveness found in modern publications. The selection of indicators reflecting the economic attractiveness of the spheres of activity of small enterprises and available for calculation on the basis of available statistical data was made: capital return, revenue per employee, the level of wages of employees. A method of complex assessment is proposed and a ranking of the economic attractiveness of fields of activity for small enterprises is carried out using various methods of criteria convolution for the transition from a multi-criteria assessment to the construction of a rating. As a result of the research, the most attractive spheres of economic activity for small enterprises have been identified: trade, repair of vehicles, construction, information and communication technologies. It is proposed to take into account the results obtained when forming a small business development policy.

"Right to the city": experience of analysis of courtyard communities from the position of critical theory (by the example of Minsk)

Traditionally, the Soviet courtyard was presented in urban studies as a sphere of attraction for the interests of most neighbours. However, the changes in the post-Soviet period (the commercialisation of public space, the stratification and segregation of citizens) significantly weakened the activity of courtyard communities. Recently, under the influence of a number of factors (the Covid-19 pandemic, the growth of socio-political activity), cities, on the contrary, are experiencing a significant civic upsurge, the traditions of spending time together in residential courtyards are gradually being renewed. The revival of the activity of courtyard communities actualises the study of issues related to the perception of citizens of their "right to the city", the boundaries and possibilities of its practical implementation, as well as the influence of communicative factors. The neo-Marxist interpretation of critical theory (A.Lefevre, D.Harvey, D.Mitchell) has been used as the methodological basis for the analysis of courtyard communities. The empirical materials collected in the course of the study (results of a questionnaire survey, supplemented by the analysis of the content of neighbours chats) revealed a number of fundamental differences between “new” courtyard communities and traditional (“Soviet”) ones. In the "Soviet" courtyard communities, urban participation was not so much the realisation of the "right to the city" as an example of communal (rural) cooperation (a form of grassroots self-organisation to achieve the set goals at the lowest cost). In the case of the "new" courtyard communities, the driving force is "urbanity" as the ability to define oneself as a city dweller, the desire to leave one's mark in the urban environment. At the same time, the "right to the city" goes beyond its utilitarian understanding (as the improvement of the urban environment) and acquires the features of symbolic self-determination, becomes the right to produce one's own identity. Courtyard communities formed on the basis of the realisation of their own “right to the city” are characterised by the ability to reach a compromise and develop generally accepted rules of communication. If such trends continue, the “right to the city” will be closely correlated with such concepts as “communication”, “public sphere”, “forum”, and its practical implementation will be less and less tied to the direct “reconquest” of physical territories and will increasingly begin to unfold in the communicative plane.

Dynamics of Interests and Positions in the Field of Economic Integration of Russia and Belarus (2019–2020)

Introduction. Economic cooperation between the Russian Federation and the Republic of Belarus is based on the platforms of the Commonwealth of Independent States, the Union State, and the Eurasian Economic Union. These associations contribute to the identification and promotion of promising business niches and areas of economic integration, taking into account the interests of the participating countries. The Union State, embodying a more multidimensional idea of integration, encourages us to turn to a deeper and more substantive analysis of the relationship between various factors and spheres. The purpose of the article is to identify positive and negative constants and dominants of economic interaction between the Russian Federation and the Republic of Belarus in the general course of integration processes in the CIS and in the context of current challenges of modernity for both countries and the Union State. Materials and Methods. The main research methods are diachronic analysis, event analysis and the method of studying documents. The main sources are materials posted on the Internet resources of integration associations with the participation of the Russian Federation and the Republic of Belarus. Results. The key actors – state and non-state participants in the economic integration of Russia and Belarus – are identified, the degree of their involvement in integration processes and the dynamics of interaction are characterized. The most attractive traditional spheres of Russian-Belarusian integration are shown, as well as new vectors determined by current needs. Discussion and Conclusion. A moderate positive scenario is considered the most likely in the field of economic integration of Russia and Belarus. The deepening of integration is determined by the content and orientation of the “road maps”, the established economic relationships and political motives in the internal and external spheres. However, the economy in the process of union building largely continues to follow politics. The necessity of closer coupling of efforts within the framework of the CGB and the EAEU is shown. At the same time, the “dissolution” of the Union State in the EAEU and subordination to it in the logic of integration development are assessed as undesirable.

Attractive Spheres of Students’ Self-realization as Practices for Supporting Their Psychological Well-being in University Education

The study is aimed at finding the varieties of appealing spheres for realization of students’ potential in higher school. The authors substantiate and develop the concept of attractors for students’ self-realization, which designate the appealing spheres and forms of manifestation of students’ personal efforts and capacities in higher education. The methods of conceptual-applied reconstruction and psychological surveys are used to determine the attractive space for students’ self-development. The study identifies a group of potentially attractive spheres (learning-cognitive, research, sports-wellness, volunteer, artistic-creative, innovative-entrepreneurial, information-media, social-civic, sphere of cross-cultural communication). The study presents the results of diagnosing the subjective significance of these spheres for students of different specialties and different levels of self-realization in education. The conclusion is made about the tendency of influence of students’ involvement in attractive spheres on the success of their self-realization in educational environment. The prospects of applying and operating the category of attractors as socio-cultural predictors of successful self-realization and psychological well-being of students in the process of University training are shown.

Designing smart triple-network cationic cryogels with outstanding efficiency and selectivity for deep cleaning of phosphate

Phosphate is one of the most difficult pollutants in the wastewaters asking for deep cleaning before discharge into the environment. To address this stringent need, novel composite sponges consisting of triple-cationic networks (TN) with cross-linked chitosan (CS) as the first network, cross-linked low molar mass branched poly(ethylene imine) (b-PEI) as the second network, and either b-PEI (TN1) or poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) (TN2) as the third network were fabricated in this work by ice-templating technique as advanced sorbents equipped not only with enhanced performances in the reversible capture of phosphate but also with a high mechanical strength. The structural and morphological characterization and the main factors influencing the sorption performances for phosphate anions of the TN sponges were evaluated in detail. The maximum sorption capacity of TN sorbents was reached at pH 4. The equilibrium data and the sorption kinetics were well described by the Sips isotherm and pseudo-second-order kinetic model, respectively. The equilibrium constant given by the Sips isotherm was used for the evaluation of the thermodynamic parameters. The sorption of phosphate onto the TN composite cryogels was endothermic and spontaneous. The presence of PDMAEMA facilitated desorption of phosphate when the temperature was in the range 30–35 °C. Hydrated iron oxide (HFO) nanoparticles were generated into the pores of cryogels to enhance the selectivity for phosphate anions. The pH effect on the sorption capacity, the influence of interfering ions and the analysis of the FTIR spectra, and desorption conditions demonstrated that the sorption mechanism of phosphate was complex consisting of the Coulomb attraction and inner sphere complexation. A great stability and recyclability were found for TN cryogels up to five sorption/desorption cycles.

Biogenic Synthesis of NiO Nanoparticles Using Areca catechu Leaf Extract and Their Antidiabetic and Cytotoxic Effects.

Nanoworld is an attractive sphere with the potential to explore novel nanomaterials with valuable applications in medicinal science. Herein, we report an efficient and ecofriendly approach for the synthesis of Nickel oxide nanoparticles (NiO NPs) via a solution combustion method using Areca catechu leaf extract. As-prepared NiO NPs were characterized using various analytical tools such as powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV-Visible spectroscopy (UV-Vis). XRD analysis illustrates that synthesized NiO NPs are hexagonal structured crystallites with an average size of 5.46 nm and a hexagonal-shaped morphology with slight agglomeration. The morphology, size, and shape of the obtained material was further confirmed using SEM and TEM analysis. In addition, as-prepared NiO NPs have shown potential antidiabetic and anticancer properties. Our results suggest that the inhibition of α-amylase enzyme with IC 50 value 268.13 µg/mL may be one of the feasible ways through which the NiO NPs exert their hypoglycemic effect. Furthermore, cytotoxic activity performed using NiO NPs exhibited against human lung cancer cell line (A549) proved that the prepared NiO NPs have significant anticancer activity with 93.349 μg/mL at 50% inhibition concentration. The biological assay results revealed that NiO NPs exhibited significant cytotoxicity against human lung cancer cell line (A549) in a dose-dependent manner from 0–100 μg/mL, showing considerable cell viability. Further, the systematic approach deliberates the NiO NPs as a function of phenolic extracts of A. catechu with vast potential for many biological and biomedical applications.

ПРОБЛЕМИ ЗАБЕЗПЕЧЕННЯ ФІНАНСОВОЇ СТІЙКОСТІ БАНКІВСЬКОЇ СИСТЕМИ

The article explores the problems of ensuring the financial sustainability of the banking sector, which plays a very important role in the functioning of the financial system of the state. The role of the stability of the banking system in ensuring conditions of economic growth is justified. It is noted that it is the financial stability of each banking institution that is a prerequisite for the stable functioning of the entire banking system. It is emphasized that since the financial stability of the banking system is influenced by a large number of internal and external factors, for the effective functioning of the banking system of the country must be ready for any challenges to the macro and microenvironment. The main problems of the banking system in modern conditions should be considered the reduction of deposits of the population, deterioration of the quality of the loan portfolio, significant devaluation of the hryvnia, high inflation rates, loss-making of a significant number of banking institutions. It was concluded that the banking system of Ukraine feels a significant dependence on the funds of depositors - individuals, and therefore on factors that affect their behavior in the financial market. Trends of formation of deposit base of commercial banks of Ukraine and imbalances in the sphere of attraction of banking resources were analyzed. The growth of bank deposits of the population is slow, negative changes in their structure are observed. The share of deposits of individuals after the 2014 crisis has become significantly more volatile and risky in terms of financial stability. The increase in lending is complicated by the presence of large portfolios of problem loans, as a result of which there are a number of tasks to increase the efficiency of the loan portfolio, which should ensure a compromise of profitability, liquidity and credit risk acceptable to the bank. The priorities of monetary policy and the main tasks are formulated, the solution of which will allow to intensify lending to the real sector of the economy. Theoretical and practical recommendations have been developed to improve bank lending, increase the profitability of the banking system and capitalize Ukrainian banks.

Detection of pimping by the criminal police

Prostitution is one of the oldest professions, which continues to destroy destinies of many people. It is revealed that sexual exploitation is an attractive sphere of activity of organized groups, because they bring high incomes at relatively insignificant capital investment in this unlawful business. It is proved that hundreds of facts of pimping and the involvement of a person in prostitution are discovered and investigated annually. We have developed of recommendations for the detection by the units of the criminal police of the facts of making pimping, with the subsequent bringing the perpetrators to responsibility, as well as providing assistance to victims of sexual exploitation, especially if they are children.

Highly effective removal of phosphate from complex water environment with porous Zr-bentonite alginate hydrogel beads: Facile synthesis and adsorption behavior study

The development of an effective phosphate removal strategy is still considered to be an important challenge in the field of wastewater remediation. In this study, novel alginate immobilized Zr-bentonite hydrogel beads were synthesized assisted by Zr-modification and Na2CO3 + HCl pore forming (abbreviated as NH-SA-ZrBT), that led to an enhancement in the specific surface area and porosity. The novel NH-SA-ZrBT adsorbent exhibited a high stability and adsorption selectivity for phosphate from complex water environments with various competitive anions, NaCl salinity and humic acid. The isotherm was fitted well by both Langmuir and Freundlich models, suggesting that the adsorption process was the chemisorption and the hydrogel beads could function through a variety of mechanisms. The maximum adsorption capacity of NH-SA-ZrBT for phosphate was calculated to be 63.61 mg/g at 25 °C by Langmuir model and had a high retention of 92.2% after five adsorption-desorption cycles. The kinetic data were better fitted by the pseudo-second model. Considering the zeta potential and XPS data before and after the phosphate adsorption, the adsorption mechanism was proposed to be a combination of electrostatic attraction, ligand exchange and inner sphere complexation. The present study demonstrates a new strategy for the fabrication of stable, separable and low-cost bentonite-containing hydrogel beads for phosphate removal from complex wastewater.

Adsorption of potentially toxic elements in water by modified biochar: A review

Biochar, as a adsorbent, can remove potentially toxic elements (PTE) in water by physical adsorption, as well as chemical interactions such as ion exchange, electrostatic attraction, surface and inner sphere complexation, precipitation, and redox. However, unsatisfactory adsorption effects and difficult recovery of adsorbents limit the application of biochar as PTE adsorbent in water. Therefore, several methods of modifying biochar have been used to improve the removal efficiency of PTE (mainly includes heavy metals and metalloids), such as physical activation with steam, chemical modification with acids, bases, metals, metal oxides, organic compounds and carbon base materials. This review explains how these methods above change the adsorption mechanism, and which method is more suitable for adsorbing a certain target pollutant than others. Physical activation contributes to an increase in specific surface area of biochar, while chemical treatments enhance the proportion of oxygen-containing functional groups and introduce new particles as adsorption sites. We focus on the removal of Pb(II), Cd(II), Cu(II), Cr(VI), Cr(VI), and As(V), evaluate the effectiveness of different modification methods in removing these heavy metals and metalloids in water. The research direction of modified biochar is prospected.

Surveying the free energy landscape of clusters of attractive colloidal spheres.

Controlling the assembly of colloidal particles into specific structures has been a long-term goal of the soft materials community. Much can be learned about the process of self-assembly by examining the early stage assembly into clusters. For the simple case of hard spheres with short-range attractions, the rigid clusters of N particles (where N is small) have been enumerated theoretically and tested experimentally. Less is known, however, about how the free energy landscapes are altered when the inter-particle potential is long-ranged. In this work, we demonstrate how adaptive biasing in molecular simulations may be used to pinpoint shifts in the stability of colloidal clusters as the inter-particle potential is varied. We also discuss the generality of our techniques and strategies for application to related molecular systems.