Chemical and Isotopic Characteristics of the Water and Suspended Particulate Materials in the Yangtze River and Their Geological and Environmental Implications

The chemical and isotopic characteristics of the water and suspended particulate materials（SPM） in the Yangtze River were investigated on the samples collected from 25 hydrological monitoring stations in the mainsteam and 13 hydrological monitoring stations in the major tributaries during 2003 to 2007. The water samples show a large variation in both δD（ 30‰ to 112‰） and δ18O（ 3.8‰ to 15.4‰） values. Both δD and δ18O values show a decrease from the river head to the Jinsha Jiang section and then increase downstream to the river mouth. It is found that the oxygen and hydrogen isotopic compositions of the Yangtze water are controlled by meteoric precipitation, evaporation, ice（and snow） melting and dam building. The Yangtze SPM concentrations show a large variation and are well corresponded to the spatial and temporal changes of flow speed, runoff and SPM supply, which are affected by the slope of the river bed, local precipitation rate, weathering intensity, erosion condition and anthropogenic activity. The Yangtze SPM consists of clay minerals, clastic silicate and carbonate minerals, heavy minerals, iron hydroxide and organic compounds. From the upper to lower reaches, the clay and clastic silicate components in SPM increase gradually, but the carbonate components decrease gradually, which may reflect changes of climate and weathering intensity in the drainage area. Compared to those of the upper crust rocks, the Yangtze SPM has lower contents of SiO2, CaO, K2 O and Na2 O and higher contents of TFe2 O3 and trace metals of Co, Ni, Cu, Zn, Pb and Cd. The ΣREE in the Yangtze SPM is also slightly higher than that of the upper crust. From the upper to lower reaches, the CaO and MgO contents in SPM decrease gradually, but the SiO2 content increases gradually, corresponding to the increase of clay minerals and decrease of the carbonates. The δ30SiSPM values（ 1.1‰ to 0.3‰） of the Yangtze SPM are similar to those of the average shale, but lower than those of the granite rocks（ 0.3‰ to 0.3‰）, reflecting the effect of silicon isotope fractionation in silicate weathering process. The δ30SiSPM values of the Yangtze SPM show a decreasing trend from the upper to the middle and lower reaches, responding to the variation of the clay content. The major anions of the river water are HCO 3, SO 4 2, Cl, NO 3, SiO 4 4 and F and the major cations include Ca2＋, Na＋, Mg2＋, K＋ and Sr2＋. The good correlation between HCO3-content and the content of Ca2＋may suggest that carbonate dissolution is the dominate contributor to the total dissolved solid（TDS） of the Yangtze River. Very good correlations are also found among contents of Cl, SO4 2, Na＋, Mg2＋, K＋and Sr2＋, indicating the important contribution of evaporite dissolution to the TDS of the Yangtze River. High TDS contents are generally found in the head water, reflecting a strong effect of evaporation in the Qinghai-Tibet Plateau. A small increase of the TDS is generally observed in the river mouth, indicating the influence of tidal intrusion. The F and NO3 contents show a clear increase trend from the upstream to downstream, reflecting the contribution of pesticides and fertilizers in the Chuan Jiang section and the middle and lower reaches. The DSi shows a decrease trend from the upstream to downstream, reflecting the effect of rice and grass growth along the Chuan Jiang section and the middle and lower reaches. The dissolved Cu, Zn and Cd in the Yangtze water are all higher than those in world large rivers, reflecting the effect of intensive mining activity along the Yangtze drainage area. The Yangtze water generally shows similar REE distribution pattern to the global shale. The δ30SiDiss values of the dissolved silicon vary from 0.5‰ to 3.7‰, which is the highest among those of the rivers studied. The δ30SiDiss values of the water in the Yangtze mainsteam show an increase trend from the upper stream to downstream. Its DSi and δ30SiDiss are influenced by multiple processes, such as weathering process, phytolith growth in plants, evaporation, phytolith dissolution, growth of fresh water diatom, adsorption and desorption of aqueous monosilicic acid on iron oxide, precipitation of silcretes and formation of clays coatings in aquifers, and human activity. The δ34SSO4 values of the Yangtze water range from 1.7‰ to 9.0‰. The SO4 in the Yangtze water are mainly from the SO4 in meteoric water, the dissolved sulfate from evaporite, and oxidation of sulfide in rocks, coal and ore deposits. The sulfate reduction and precipitation process can also affect the sulfur isotope composition of the Yangtze water. The87Sr/86Sr ratios of the Yangtze water range from 0.70823 to 0.71590, with an average value of 0.71084. The87Sr/86Sr ratio and Sr concentration are primary controlled by mixing of various sources with different87Sr/86Sr ratios and Sr contents, including the limestone, evaporite and the silicate rocks. The atmospheric precipitation and anthropogenic inputs can also contribute some Sr to the river. The δ11B values of the dissolved B in the Yangtze water range from 2.0‰ to 18.3‰, which is affected by multifactors, such as silicate weathering, carbonate weathering, evaporite dissolution, atmospheric deposition, and anthropogenic inputs.

Chemical and Isotopic Characters of the Water and Suspended Particulate Materials in the Yellow River and Their Geological and Environmental Implications

The chemical and isotopic characteristics of the water and suspended particulate materials （SPM） in the Yellow River were investigated on the samples collected from 29 hydrological monitoring stations in the mainstem and several major tributaries during 2004 to 2007. The JD and δ^18O values of the Yellow River water vary in large ranges from -32%0 to -91‰ and from -3.1‰ to -12.5‰, respectively. The characters of H and O isotope variations indicate that the major sources of the Yellow River water are meteoric water and snow melting water, and water cycle in the Yellow River basin is affected strongly by evaporation process and human activity. The average SPM content （9.635 g/L） of the Yellow River is the highest among the world large rivers. Compared with the Yangtze River, the Yellow River SPM has much lower clay content and significantly higher contents of clastic silicates and carbonates. In comparison to the upper crust rocks, the Yellow River SPM contains less SiO2, CaO, K2O and Na2O, but more TFe203, Co, Ni, Cu, Zn, Pb and Cd. The abnormal high Cd contents found in some sample may be related to local industrial activity. The REE contents and distribution pattern of the Yellow River SPM are very close to the average value of the global shale. The average δ^30Sisp in the Yellow River （-0.11‰） is slightly higher than the average value （-0.22‰） of the Yangtze River SPM. The major factors controlling the δ^30Si SPM of the Yellow River are the soil supply, the isotopic composition of the soil and the climate conditions. The TDS in the Yellow River are the highest among those of world large rivers. Fair correlations are observed among Cl, Na^＋, K^＋, and Mg^2＋ contents of the Yellow River water, indicating the effect of evaporation. The Ca^2＋ and Sr^2＋ concentrations show good correlation to the SO42 concentration rather than HCO3-concentration, reflecting its origin from evaporates. The NO3-contents are affected by farmland fertilization. The Cu, Zn and Cd contents in dissolved load of the Yellow River water are all higher than those of average world large rivers, reflecting the effect of human activity. The dissolved load in the Yellow River water generally shows a REE distribution pattern parallel to those for the Yangtze River and the Xijiang River. The δ^30Si values of the dissolved silicon vary in a range from 0.4%0 to 2.9%0, averaging 1.34%o. The major processes controlling the Dsi weathering process of silicate rocks, growth of and δ^30SiDiss of the Yellow River water are the phytolith in plants, evaporation, dissolution of phytolith in soil, growth of fresh water diatom, adsorption and desorption of aqueous monosilicic acid on iron oxide and human activities. The average δ^30^SiDiss value of the Yellow River is significantly lower than that of the Nile River, Yangtze River and Siberia rivers, but higher than those of other rivers, reflecting their differences in chemical weathering and biological activity. The δ^34SSO4 values of the Yellow River water range from -3.8%0 to 14.1%o, averaging 7.97%0. There is some correlation between SO4^2- content and δ^34SSO4. The factors controlling the δ^34SSO4 of the Yellow River water are the SO4 in the meteoric water, the SO4 from gypsum or anhydrite in evaporite rocks, oxidation and dissolution of sulfides in the mineral deposits, magmatic rocks and sedimentary rocks, the sulfate reduction and precipitation process and the sulfate from fertilizer. The ^87Sr/^86Sr ratios of all samples range from 0.71041 to 0.71237, averaging 0.71128. The variations in the ^87Sr/^86Sr ratio and Sr concentration of river water are primarily caused by mixing of waters of various origins with different 87Sr/S6Sr ratios and Sr contents resulting from water-rock interaction with different rock types.

Calibration of the simulation parameters of the particulate materials in film mixed materials

In order to obtain accurate contact parameters of a particulate material in residual film mixture collected by cotton field machine in Xinjiang,the angle of repose test and inclined plane test were carried out.In the tests,the angles of repose of the particulate material with the water content of(6.26±1.5)%and(14.1±2.1)%were measured respectively,as well as the static sliding friction angle between the particulate material and the residual film.At the same time,the EDEM software was used to calibrate the coefficient of restitution,static friction coefficient and dynamic friction coefficient between the material and the film.Then,the second-order response model between contact parameters and the angle of repose and static sliding friction angle was constructed.In addition,the optimal contact parameters between the granular materials and the mulch were obtained by fitting the physical test data.The results indicated that the errors between the physical test results and the numerical simulation results are small.It was proved that the second-order response model could predict the repose angle of granular materials and the static sliding friction angle between granular materials and farmland film.This study could provide theoretical support for the subsequent model construction of the residual film mixture collected by the cotton field machine.

Particulate Materials: Synthesis, Characterization, Processing and Modeling, by Chuan-Yu Wu and Wei Ge, RSC Publishing, The Royal Society of Chemistry, 2012

This book records a collection of 42 selected papers presented at UK-China Particle Technology Forum Ⅲ held at Birmingham, UI〈, on 2011-7-3/6. The prior Forum Ⅱ was held in Guiyang, China in 2009, and Forum Ⅰ in Leeds, UK in 2007. This Forum Ⅲ was classified in this book into four topics totaling 42 presentations, each represented in this review by the first two papers, as follows：

State-of-the-Art and Perspectives in the Field of Particulate Nanostructured Materials

A great attention has been paid to the research and development of nanostructured materials.The main preparation methods of ultrafine particles and nanostructured materials have been summarized. The applications of zone typical nanostructured materials have also been reviewed.The peculiar characteristics and properties. such as density, grain size, hardness, superplasticity,magnetic and catalytic properties have been discussed

Atmospheric Pollutants in a Commercial Region of Fortaleza, Ceará, Brazil: Integration of Health, Environment and Economy in Urban Planning to Improve Air Quality

The accelerated growth of the vehicular fleet, the modernization of large urban centers, and the few adjustments to the road network in Fortaleza have intensified the problems of traffic and emissions of atmospheric pollutants, highlighting the necessity for strategic urban planning initiatives to address the escalating issues of traffic and pollution. With the objective of analyzing the indices of concentrations of atmospheric pollutants and estimating how these levels can affect human health, this work consists of a study of the analysis of air quality in the intense trade region of Fortaleza. For this, the analysis zone was divided into three perimeters (Major - Medium - Minor), where each perimeter was analyzed at 7 am, 12 noon and 5 pm. Concentrations of the type of O3, particulate matter (PM2.5 and PM10), CO2 and HCHO were collected. Our results demonstrate that most of the analyses are within the limits of current legislation;however, at certain times and perimeters, the analyses of CO2 and HCHO exceeded the established limits. In view of the above, we conclude that public policies to control air quality are necessary to reduce the damage to human health and the environment caused by pollutants.

Geochemical elements in suspended particulate matter of Ensenada de La Paz Lagoon,Baja California Peninsula,Mexico:Sources,distribution,mass balance and ecotoxicological risks

The present study aimed to evaluate multi-element concentrations(Al,As,Ca,Cd,Co,Cr,Cu,Fe,Mg,Mn,Mo,Ni,Pb,Sr)in suspended particulate material(SPM)collected from Ensenada de La Paz(ELP)lagoon,Baja California Sur,Mexico in two different periods(September and May)to comprehend their origin,geochemical behavior,mass transfer and associated ecotoxicological risks.The 24 hr variation coefficient of volumetric SPM levels were found to be 51.7%in September and 40.5%in May,signifying the effects of oceanic waters.The calculated enrichment factor(EF)values for all the studied elements were of higher magnitude because of the high surface area and oxide nature of SPM,and in this study,Mo had the highest EF of 46.77 probably due to its origin from continental weathering.From the ecotoxicological perspective,the integrated toxic risk index revealed low toxic risk to the benthic community.However,the mean-ERM-Quotient calculated using the particulate concentrations of As,Cd,Cr,Cu,Ni,Pb indicated 9%probability of toxicity to biota.The comprehensive geochemical and ecotoxicological assessment of particulate metal concentrations in the ELP lagoon signify low to moderate contamination.

Rare earth element content in the SPM of Daliao river system and its comparison with that in the sediments, loess and soils in China

Content and distribution patterns of rare earth dements （REEs） in the suspended particulate material （SPM） of Daliao River system were investigated and compared with those in the fiver and sea sediments, loess, and soils of China. Twenty-seven samples of SPM were taken in Daliao River system and digested with various acids followed by ICP-MS analysis for REEs and ICP-OES analysis for Al, Fe, Mn, Ti, Mg, Ca, Na, and K, to measure the total concentrations of these elements. Results indicated that the spatial change in the content of REEs was great, with the coefficient of variance （CV） from 84% to 105%, while the contents of REEs were significantly correlated with each other. Chondrite-normalized patterns of REEs were characterized by higher enrichment of light REEs than heavy REEs, and a depletion of Eu in the SPM was generally found. The positive anomaly of Eu in the SPM of Xi River was due to anthropogenic source in Shenyang City. Furthermore, chondfite- and upper continent crust-normalized patterns of REEs in the SPM of Daliao River system, sediments of Yangtze River and Yellow River, sediments of Yellow Sea, East Sea, South Sea of China, and loess and soil of China, were very similar to one another. These demonstrated that the weathering and sedimentary processes resulted in constant REE distribution not only in the typical sedimentary rocks, but also in the modem riverine particle, sea sediments, loess, and soils.

DEM Simulations of Resistance of Particle to Intruders during Quasistatic Penetrations

Based on the discrete element method and hydrostatics theory,an improved Archimedes principle is proposed to study the rules pertaining to resistance changes during the penetration process of an intruder into the particulate materials.The results illustrate the fact that the lateral contribution to the resistance is very small,while the tangential force of the lateral resistance originates from friction effects.Conversely,the resistance of particulate materials on the intruder mainly occurs at the bottom part of the intruding object.Correspondingly,the factors that determine the resistance of the bottom part of the intruding object and the rules pertaining to resistance changes are analyzed.It is found that when the volume density and friction coefficient of the particles and the radius of the bottom surface of the cylindrical intruder are varied,the resistance–depth curve consists of a nonlinear segment and a linear region.The intersection of the two stages occurs at the same location h/˜R=0.15±0.055.The slope of the linear stage is determined by the friction coefficient of the particles.Accordingly,the relationship between the slope and the friction coefficient is quantified.Finally,it is shown that the slope is independent of the geometry of the intruder.

Nanoporous metal organic framework materials for hydrogen storage

Hydrogen is expected to play an important role in future transportation as a promising alternative clean energy source to carbon-based fuels. One of the key challenges to commercialize hydrogen energy is to develop appropriate onboard hydrogen storage systems, capable of charging and discharging large quantities of hydrogen with fast enough kinetics to meet commercial requirements. Metal organic framework （MOF） is a new type of inorganic and organic hybrid nanoporous particulate materials. Its diverse networks can enhance hydrogen storage through tuning the structure and property of MOFs. The MOF materials so far developed adsorb hydrogen through weak dispersion interactions, which allow significant quantity of hydrogen to be stored at cryogenic temperatures with fast kinetics. Novel MOFs are being developed to strengthen the interactions between hydrogen and MOFs in order to store hydrogen under ambient conditions. This review surveys the development of such candidate materials, their performance and future research needs.

Audio-frequency heating of particulate magnetic systems

This paper presents theoretical and experimental studies on the magnetodynamics and energy dissipation in suspensions of small ferromagnetic particles with magnetic hysteresis and mechanical mobility in an AC magnetic field. Energy absorption by particles suspended in a solid, liquid or gas environment and subjected to high frequency magnetic fields is of great interest for cancer treatment by hyperthermia, chemical technology, biotechnology and smart materials science. Sub-micron needle-like γ-Fe2O3 particles dispersed in liquid were subjected in this study to a 430 Hz magnetic field with an intensity of up to 10^5 A/m. Dynamic magnetization loops were measured in parallel to the energy dissipated in the samples. Combined magnetomechanical dynamics of particle dispersions was simulated by using a chain-of-spheres model allowing for incoherent magnetic field reversal. In liquid dispersions, within the kilohertz frequency range, the mechanical mobility of particles does not interfere with their hysteretic magnetic reversal that makes heat release comparable to that observed with solids; for instance, in the present study using γ-Fe2O3 particles in liquid subjected to 10^4 Hz field exhibited heat release rates from 250 up to 600W oer 1 cm^3 of the dry oarticle content.

THEORY OF NONFLUIDIZED GAS SOLIDS FLOW AND ITS APPLICATION

A theory of nonfluidized gas-solids flow, which combines the theory of multiphase flow with the mechanics of particulate media, was proposed on the basis of understanding that the particles contact each other, solids and gas are in movement, and the drag force on the particles caused by interstitial gas flow is similar to gravity force having the property of mass force. Then this theory was verified by experiments on vertical and inclined moving beds, and was applied to calculation and design of equipment and devices with moving beds, such as pneumatic moving bed transport, dipleg, V-value, L-valve, orifice flow, and arching prevention. It can be used to guide the design and operation of moving beds and fixed beds.