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With the population increasing, fish communities, as important components in the river system, were inescapably impacted by human activities. To investigate these impacts, we characterized the fish community's composition by environmental DNA metabarcoding in the urban and suburban sites along Xiang River in central China. The results showed that 32 species were identified, and most species were from Cypriniform. The analysis indicated no significant differences in fish communities among the three urban areas. However, significant differences were observed between the bank solidified and non-solidified areas, which indicated that the channelization significantly influenced the biodiversity and abundances. An alien species, Clarias gariepinus, was discovered in all examined sites, and it was negatively associated with ten native species. Furthermore, human populations and acidification were also negatively related to diversity. Our findings clearly showed that the consequences of anthropogenic activities shaped ichthyofauna and caused biodiversity loss in the urban river.

The Gangdese batholith, emplaced from the Cretaceous to the Eocene in the southern Lhasa terrane of Tibet, provides critical constraints on the tectonic-magmatic evolution of the Neo-Tethyan Ocean and the India-Asia continental collision. In this article, we report new data for the Laimailang monzogranite in the southern Gangdese, including major and trace element analyses, zircon U–Pb dating, and in situ Hf isotope analyses. In situ zircon U–Pb dating of sample yielded Late Cretaceous ages (ca. 81 Ma). The monzogranite is characterized by relatively high-silica (≥56 wt% SiO2), Na-rich, and high-Al granitoids that are characterized by high Sr, low Y and HREE contents and strongly fractionated REE patterns, with no significant Eu anomaly, indicating that they are consistent with the definition of adakite. These monzogranite have high K2O (2.92–6.5%) and negative ε Hf(t) (−2.1 to −5.4), suggesting that these rocks were likely derived from the partial melting of the lower continental crust. We conclude that the Laimailang rocks of adakitic affinity were derived due to the melting of the thickened lower continental crust in the late Cretaceous.

Aim: To date, few studies have examined the phylogenetics of Corbicula clams in their native range and the environmental parameters influencing their distribution, although this could provide great insights into the biological adaptation and invasion dynamics of Corbicula clams. We sought to identify the genetic lineages of native Corbicula clams and elucidate the environmental factors shaping the distributions of identified lineages. Location: China, mainly the Yangtze River Basin. Methods: The alignment comprised 558 COI sequences including samples from China and 222 COI sequences from published studies. This dataset was used to generate phylogenetic trees and compare population diversity. We used dbRDA method to assess the relationship between these COI data and environmental factors measured to identify the important factors affecting Corbicula's distribution. Results: The COI phylogenetic tree delineated the monophyly of 3 major COI clades and 77 distinct COI haplotypes in the Yangtze River Basin. The invasive lineage C/S (FW17) was not identified in our sampling in China, while invasive lineages A/R (FW5 = Hap6), B (FW1 = Hap17) and Rlc (FW4 = Hap43) were identified, abundant and widely distributed in the middle and lower reaches of Yangtze River. Focusing on populations from Yangtze River Basin, both the COI haplotype and nucleotide diversity in the lakes along the Yangtze River increased with longitude, except for the river mouth population. The AMOVA tests showed significant differentiation between the middle and lower reaches of the Yangtze River and among populations. The dbRDA results suggested that the parameter chloride explained most of the spatial COI haplotype distribution variation in the Yangtze River Basin, with the three invasive lineages tolerating broad fluctuations of salinity (chloride levels ranging from 4 to 60 mg/L). Conclusions: The Corbicula COI haplotypes found within the Yangtze River Basin had distinct distribution preferences, with the invasive androgenetic lineages being the most abundant and widely distributed. Genetic diversity was higher in this native region than in invaded areas in Europe and America, while it decreased with increasing distance from the river mouth. Salinity appeared to be the main environmental factor shaping the COI haplotype distribution of Corbicula lineages within their native range.

Combined heat and power economic dispatch (CHPED) is an important issue in the energy field, since it has great potential in improving the utilization efficiency of power and heat energies. This paper proposes a modified genetic algorithm (MGA) to determine the power and heat outputs of three kinds of units for CHPED. First, MGA replaces the simulated binary crossover by a new one based on the uniform and guassian distributions, and its convergence can be enhanced. Second, MGA modifies the mutation operator by introducing a disturbance coefficient based on guassian distribution, which can decrease the risk of being trapped into local optima. Eight instances with or without prohibited operating zones are used to investigate the efficiencies of MGA and other four genetic algorithms for CHPED. MGA attains the smallest mean and standard deviation related to 50 cost values for every instance, thus it has desirable convergence and stability for CHPED in comparison with the other four genetic algorithms.

To date, there is still very little knowledge about the combined effects of typical inorganic ligands and solution pH values on mobility characteristics of tetracycline (TC) through saturated aquifer media. In this work, three typical inorganic ligands (

Bacillidium spp. exclusively infect oligochaetes and these microsporidian pathogens are typically characterized by their rod-shaped spores. Seven Bacillidium spp. are presently reported from different organs of oligochaetes. Here, we describe two new Bacillidium species, Bacillidium sinensis n. sp. and Bacillidium branchilis n. sp., from coelomocytes of Branchiura sowerbyi. This is the first report of Bacillidium spp. in oligochaetes from China. Both species of Bacillidium elicit the formations of opaque xenoma-like lesions in coelomocytes of the host. A diplokaryotic nucleus occurs in all life stages of these two new Bacillidium species. Mature spores of B. sinensis are 15.9 ± 0.6 (14.7-17.1) μm long (average ± standard error, range, n = 50) and 2.5 ± 0.1 (2.3-2.7) μm wide in fresh preparations. A new type of exospore (sixteen-layered exospore) is discovered from B. sinensis n. sp. which is distinctly different from B. branchilis n. sp., and other Bacillidium spp. (double-layered exospore) reported previously. These two Bacillidium species are morphologically distinguished from each other and all Bacillidium spp. described previously in terms of hosts, infection sites, spore size, spore wall or polar filament thickness. BLASTn searches indicated that these two new microsporidian parasites are surprisingly most similar to Janacekia tainanus (94.76% for B. sinensis and 90. 2% for B. branchilis) isolated from the fat body of midge larva (Kiefferulus tainanus). Phylogenetic analysis demonstrates that the two novel taxons cluster with J. debaisieuxi, J. tainanus, and Bacillidium sp. within the Jirovecia-Bacillidium-Janacekia clade. Other available 18S rRNA gene sequences for microsporidia that infect oligochaetes include J. sinensis, B. vesiculoformis, Neoflabelliforma aurantiae, and Bacillidium sp., but these do not form a single cluster with B. sinensis and B. branchilis, but are instead dispersed through the clade. Based on the ultrastructural features and molecular characteristics, two new species within the genus Bacillidium, B. sinensis n. sp. and B. branchilis n. sp., are designated.

Given the ubiquity and abundance of the iron oxide minerals and their important roles in affecting the environmental fate of graphene oxide (GO) nanoparticles, the attachment of GO onto three iron oxide minerals (i.e., hematite, goethite, and ferrihydrite) under different solution chemistry conditions was investigated in this study. The main mechanism of the attachment of GO was electrostatic interaction. Calculations based on the DLVO theory showed that the attachment was a favorable process. Interestingly, the affinity of GO towards three iron oxide minerals was in the order of ferrihydrite > goethite > hematite. This result indicates that different characteristics of various iron oxides (e.g., specific surface area, crystal structure, and surface charge, and surface hydroxyl densities) can influence their attachment capacities for GO. The attachment of GO depended on the solution pH and ionic strength. Electrostatic attraction and hydrogen bonding were the important retention mechanisms for GO attachment when pH pHPZC, respectively. The attachment capacities of iron oxides decreased with increasing ionic strength at lower pH because of the decrease of the electrostatic attraction. Meanwhile, the presence of divalent cations (i.e., Ca2+ and Cu2+) could significantly promote GO attachment mainly by the surface-bridging mechanism. Meanwhile, the enhancement effect of Cu2+ was greater than Ca2+ due to the greater complexation affinity of Cu2+. Furthermore, attachment isotherms showed that the presence of phosphate could inhibit the attachment of GO onto minerals obviously. Because phosphate could form inner-sphere surface complex on the iron oxide surface, and consequently decreased the electrostatic attraction between nanoparticles and minerals. Our study has important implications for predicting the fate of GO in natural environment where amounts of iron oxide minerals are present.

Background The restoration of lake ecosystems requires a good knowledge of the lake’s history and the driving mechanism of environmental changes. In this study, we used Lake Datong, the largest inland lake in Hunan Province China, as an example to study the effects of aquaculture, based on historical data of aquatic creature, diatom inferred-total phosphorous (DI-TP) data, and an Ecopath model. Lake Datong has undergone several stages of aquaculture from 1980, with a rapid increase in fish production and fish feed supplementation at each stage. Its water quality has deteriorated since the introduction of aquaculture and the lake has become moderate eutrophic status. Results According to the DI-TP data, before 1930, Lake Datong was in a mesotrophic status (50–60 μg/L DI-TP). Between 1930 and 1980, the number of nutrient-tolerant species increased slightly, which indicates a nutrient increase in the lake (66–83 μg/L DI-TP). From the 1980s to 2010 and especially since 2000, eutrophication increased rapidly, with eutrophic species dominating the diatom assemblage, such as Stephanodiscus hantzschii, S. minutulus, and a sudden decrease in Aulacoseira granulata ( Conclusions The succession of the water ecosystem of Lake Datong is reappeared by DI-TP analysis and historical reference data. Lake Datong has experienced four stages of eutrophication succession following the introduction of aquaculture activities, with dramatic changes in the composition and biomass of its aquatic creatures. After comprehensive management in 2017, the consumer biomass of Lake Datong was at a relatively lower level, and the biomass of submerged macrophytes was higher, meaning a large quantity of primary producers had not been used by consumers, thus had not entered the food web, which consequently reduces the energy TE of the ecosystem. Future management needs to pay attention to making a suitable macrophyte harvest plan, stocking herbivorous and omnivorous fish, and establishing rational fishing, which can not only enhance the energy flows and nutrient cycling of the ecosystem, but also improve the food web structure. Our results provide important reference values and theoretical support for decision-makers and stakeholders in the subsequent management of similar shallow lake-water ecosystems.

Background Endoscopic retrograde appendicitis therapy (ERAT) is a new and minimally invasive technique for the treatment of acute appendicitis. This study aimed to assess the efficacy and clinical outcomes of ERAT versus laparoscopic appendectomy for patients with uncomplicated acute appendicitis. Methods We adopted propensity score matching (1:1) to compare ERAT and laparoscopic appendectomy in patients with uncomplicated acute appendicitis between April 2017 and March 2020. We reviewed 2880 patients with suspected acute appendicitis, of whom 422 patients with uncomplicated acute appendicitis met the matching criteria (ERAT 79; laparoscopic appendectomy 343), yielding 78 pairs of patients. Results The rate of curative treatment within 1 year after ERAT was 92.1 % (95 % confidence interval [CI] 83.8 % to 96.3 %). The percentage of patients recording visual analog scale values of ≤ 3 for pain at 6 hours after treatment was 94.7 % (95 %CI 87.2 % to 97.9 %) in the ERAT group, which was significantly higher than that in the laparoscopic appendectomy group (83.3 %; 95 %CI 73.5 % to 90.0 %). Median procedure time and median hospital length of stay were significantly lower in the ERAT group compared with the laparoscopic appendectomy group. At 1 year, the median recurrence time was 50 days (interquartile range 25–127) in the ERAT group. The overall adverse event rate was 24.4 % (95 %CI 14.8 % to 33.9 %) in the laparoscopic appendectomy group and 18.4 % (95 %CI 9.7 % to 27.1 %) in the ERAT group, with no significant difference between the two groups. Conclusion ERAT was a technically feasible method of treating uncomplicated acute appendicitis compared with laparoscopic appendectomy.

Invasive bivalves continue to spread and negatively impact freshwater ecosystems worldwide. As different metrics for body size and biomass are frequently used within the literature to standardise bivalve-related ecological impacts (e.g. respiration and filtration rates), the lack of broadly applicable conversion equations currently hinders reliable comparison across bivalve populations. To facilitate improved comparative assessment among studies originating from disparate geographical locations, we report body size and biomass conversion equations for six invasive freshwater bivalves (or species complex members) worldwide: Corbicula fluminea, C. largillierti, Dreissena bugensis, D. polymorpha, Limnoperna fortunei and Sinanodonta woodiana, and tested the reliability (i.e. precision and accuracy) of these equations. Body size (length, width and height) and biomass metrics of living-weight (LW), wet-weight (WW), dry-weight (DW), dry shell-weight (SW), shell free dry-weight (SFDW) and ash-free dry-weight (AFDW) were collected from a total of 44 bivalve populations located in Asia, the Americas and Europe. Relationships between body size and individual biomass metrics, as well as proportional weight-to-weight conversion factors, were determined. For most species, although inherent variation existed between sampled populations, body size directional measurements were found to be good predictors of all biomass metrics (e.g. length to LW, WW, SW or DW: R2 = 0.82–0.96), with moderate to high accuracy for mean absolute error (MAE): ±9.14%–24.19%. Similarly, narrow 95% confidence limits and low MAE were observed for most proportional biomass relationships, indicating high reliability for the calculated conversion factors (e.g. LW to AFDW; CI range: 0.7–2.0, MAE: ±0.7%–2.0%). Synthesis and applications. Our derived biomass prediction equations can be used to rapidly estimate the biologically active biomass of the assessed species, based on simpler biomass or body size measurements for a wide range of situations globally. This allows for the calculation of approximate average indicators that, when combined with density data, can be used to estimate biomass per geographical unit-area and contribute to quantification of population-level effects. These general equations will support meta-analyses, and allow for comparative assessment of historic and contemporary data. Overall, these equations will enable conservation managers to better understand and predict ecological impacts of these bivalves. Fil: Coughlan, Neil E.. The Queens University of Belfast; Irlanda. University College Cork; Irlanda Fil: Cunningham, Eoghan M.. The Queens University of Belfast; Irlanda Fil: Cuthbert, Ross N.. The Queens University of Belfast; Irlanda. Geomar-Helmholtz Centre for Ocean Research Kiel; Alemania Fil: Joyce, Patrick W. S.. The Queens University of Belfast; Irlanda Fil: Anastácio, Pedro. Universidade de Évora; Portugal Fil: Banha, Filipe. Universidade de Évora; Portugal Fil: Bonel, Nicolás. Université Montpellier II; Francia. Centre National de la Recherche Scientifique; Francia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina Fil: Bradbeer, Stephanie J.. University of Leeds; Reino Unido Fil: Briski, Elizabeta. Geomar-Helmholtz Centre for Ocean Research Kiel; Alemania Fil: Butitta, Vince L.. University of Wisconsin; Estados Unidos Fil: Cadková, Zuzana. Czech University of Life Sciences; República Checa Fil: Dick, Jaimie T. A.. The Queens University of Belfast; Irlanda Fil: Douda, Karel. Czech University of Life Sciences; República Checa Fil: Eagling, Lawrence E.. The Queens University of Belfast; Irlanda Fil: Ferreira Rodríguez, Noé. Universidad de Vigo; España Fil: Hünicken, Leandro Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Johansson, Mattias L.. University of North Georgia; Estados Unidos Fil: Kregting, Louise. The Queens University of Belfast; Irlanda Fil: Labecka, Anna Maria. Jagiellonian University; Polonia Fil: Li, Deliang. Hunan Agricultural University; China Fil: Liquin, Florencia Fernanda. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Instituto para el Estudio de la Biodiversidad de Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta; Argentina Fil: Marescaux, Jonathan. University of Namur; Bélgica. e-biom; Bélgica Fil: Morris, Todd J.. Fisheries and Ocean Canada; Canadá Fil: Nowakowska, Patrycja. University of Gdansk; Polonia Fil: Ozgo, Malgorzata. Kazimierz Wielki University; Polonia Fil: Paolucci, Esteban Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Peribáñez, Miguel A.. Universidad de Zaragoza; España Fil: Riccardi, Nicoletta. Consiglio Nazionale delle Ricerche; Italia Fil: Smith, Emily R. C.. University College London; Estados Unidos Fil: Sylvester, Francisco. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Instituto para el Estudio de la Biodiversidad de Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta; Argentina

Loma psittaca, previously described as inhabiting the intestinal mucosa of an anadromous fish, Colomesus pisttacus, from the Amazon Basin, is reported as being found for the first time in a marine fish, the hybrid grouper (Epinephelus lanceolatus♂×Epinephelus fuscoguttatus♀), from Lingshui city, Hainan Province, China, expanding the geographical distribution and host range of this parasite. Numerous whitish xenomas (0.5-0.7 mm in diameter) of this new isolate of L. psittaca were found distinctly in the muscle layer of the host stomach wall. Electron microscopic observations showed a monokaryotic nucleus in all developmental stages. Round or elongated multinucleate merogonial plasmodia surrounded by numerous mitochondria were observed initially, subsequently transforming into uninucleate sporonts through multiple fissions. Sporonts, each with a large centrally positioned nucleus, further developed into sporoblasts. Each sporoblast mother cell gave rise to two uninucleate sporoblasts by binary fission. Mature spores were ellipsoidal, measuring 4.0 ± 0.3 (3.7-4.3) μm in length and 2.2 ± 0.2 (2.1-2.5) μm in width. Spores possessed a mushroom-like anchoring disk, a bipartite polarplast, isofilar polar filaments arranged in 12-14 turns in one row, and a trilaminar spore wall. The obtained partial SSU rRNA gene sequence of the new isolate was 1330 bp in length and showed 99.4% sequence similarity with an estuary isolate of L. psittaca previously reported in South America. SSU rRNA gene-based phylogenetic analyses demonstrated that the two L. psittaca isolates first clustered together and then formed a dichotomy that included the digestive-tract-infecting Loma species, L. acerinae, with high support values within group I.

Inorganic ligands, ubiquitous in the natural environment, can interact with iron oxide minerals. To date, our knowledge regarding the effects of inorganic ligands on the adsorption properties of antibiotics onto iron oxides is still limited. In this work, the influences of different inorganic ligands (chosen iodate, silicate, and phosphate as the model ligands) on the adsorption of tetracycline (TC) onto hematite were examined. Adsorption isotherms indicated that inorganic ligands inhibited TC adsorption. The observations were attributed to the increase of electrostatic repulsion between anionic species (i.e., TC–) and negatively charged hematite particles as well as the competition between TC– species and inorganic ligand anions for the adsorption sites on hematite surfaces. Interestingly, the inhibitory effects of the three inorganic ligands were in the order of phosphate > silicate > iodate; the trend was stemmed from their differences in the binding affinities to hematite and the molecular size. When the background solutions contained divalent cations (e.g., Ca2+), surface precipitation of Ca-inorganic ligand compounds on hematite was another important mechanism for the inhibitory effects. Furthermore, adsorption of TC onto hematite with or without inorganic ligands was strongly affected by solution pH, which was due to the combination of the amphoteric behavior of TC and highly pH-dependent surface charges of the hematite mineral. Current results highlight the critical roles of ubiquitous inorganic ligands in revealing the fate of tetracycline antibiotics in natural systems.

The Shaximiao Formation is one of the important Mesozoic burial horizons of dinosaur fossils in the Sichuan Basin. Although a large number of research results on the stratigraphic age of the Shaximiao Formation have been published, the age and division of the Shaximiao Formation are still controversial. To a certain extent, this affects the precise constraints on the burial age of the dinosaur fauna in Yunyang, Chongqing. In this study, the newly discovered tuff intercalation in the Lower Shaximiao Formation in Pu'an Township, Yunyang County, Chongqing City, was taken as the research object, and its lithology and formation age were determined using thin section identification, X-ray diffraction (XRD), scanning electron microscopy (SEM), and U-Pb zircon dating. The field observations and thin section microscopic characteristics of the rocks reveal that the clay rock intercalation has a typical sedimentary tuff structure, which is altered lithic tuff. The SEM imaging and XRD results indicate that it has a typical tuff mineral composition. The U-Pb zircon dating shows that the weighted average age of the newly discovered tuff is 174.8 ± 2.4 Ma, and the burial age of the dinosaur fossils is estimated to be 174.7 ± 2.4 Ma based on the sedimentation rate and the thickness of the stratum. Key words: Sichuan Basin; Shaximiao Formation; Yunyang Dinosaur Fauna; Tuff; Burial Age

The transport of tetracycline possessed a great challenge in its environmental applications. This study looked at how various low-molecular-weight organic acids (LMWOAs) affect the transport of tetracycline in environments. To that end, four LMWOAs were employed in experiments; acetic acid, malonic acid, malic acid, and citric acid. It was observed that LMWOAs promoted the tetracycline passage in presence of various experimental environments. The LMWOAs steric hindrance and deposition competition facilitated tetracycline transport at pH 5.0. The other deposition mechanism for tetracycline was the electrostatic repulsion between tetracycline and sand enhanced by deprotonated LMWOAs at pH 7.0. Moreover, the enhanced effects of LMWOAs on tetracycline mobility were intensively dependent on LMWOA type with more functional groups (e.g. carboxyl and hydroxyl groups) and larger molecular size supported stronger deposition competition, steric hindrance as well as electrostatic repulsion. Additionally, cation-bridging played a vital role for the enhanced effects of LMWOAs on tetracycline transport with divalent cations (e.g., Ca2+ and Pb2+). Interestingly, tetracycline exhibited a higher mobility in the presence of Ca2+ relative to Pb2+ regardless of LMWOAs-free or LMWOAs-addition. This phenomenon was attributed to the fact that Pb2+ has a greater affinity with tetracycline and LMWOAs than Ca2+. Furthermore, under the shadow of numerous LMWOAs, the non-equilibrium two site transportation model was employed to investigate the movement of tetracycline in porous saturated media. The present study suggests that LMWOAs may be important considerations in assessing the antibiotic passage in soil as well as groundwater.

Photocatalytic reduction of CO2 with H2O is a fascinating approach to convert CO2 into available fuels using solar energy as driven force. However, it still suffers from low efficiency owing to the instinct stability of CO2. In this work, a hybrid photocatalyst of rutile TiO2 nanorods supported on MgAl layered double oxides (TiO2/MgAl-LDO) were designed and facilely fabricated via an in situ growth followed by a high temperature calcination process. The resulted TiO2/MgAl-LDO demonstrated significantly enhanced photocatalytic reduction of CO2 with the optimal CO and CH4 evolution of 0.65 and 1.60 μmol in 8 h reaction under ambient temperature, which is ca. 4.6 and 48 times that of TiO2 respectively. X-ray photoelectron spectroscopy revealed a strong electron interaction between TiO2 and MgAl-LDO, as well as electrochemical characterization showed enhanced photocurrent, suggesting a promoted charge separation in photocatalytic process. CO2-temperature-programmed desorption (CO2-TPD) unveiled the relatively active bicarbonate, bidentate carbonate and monodentate carbonate species were formed on MgAl-LDO, which could boost the CO2 reduction half-reaction. Meanwhile, NH3-TPD revealed acidic sites existed in TiO2/MgAl-LDO, which could act as active sites for H2O adsorption and activation and thus promote the H2O oxidation half-reaction. The strategy of simultaneous promotion on the reduction and the oxidation half-reactions will open a new vane to fabricate highly efficient catalysts toward photocatalytic reduction of CO2 with H2O. A hybrid photocatalyst of MgAl layered double oxides supported rutile TiO2 with abundant acidic and/or basic sites exhibit significant enhancement on the photocatalytic reduction of CO2 with H2O under ambient temperature.

Different speciation of heavy metal ions has different toxicity level. The different speciation contents can be used as an important basis to evaluate the passivation efficiency of passivator. In this study, Ni2+, Cu2+ and Zn2+ in soil was passivated with thiol-functionalized nano-silica by solidification/stabilization technology, and the behavior of heavy metal ions in soil were explored. The result shows that, passivation time, soil moisture and passivator dosage can influence the toxicity of heavy metal ions via changing the speciation of metal ions. Passivation time and passivator dosage will promote passivation efficiency, while too low or too high soil moisture are not conducive to the passivation. The change of soil moisture will affect the surface charge distribution of soil and passivator, thus influence the migration of metal ions. According to speciation analysis, four kinds of speciation could be transferred reciprocally and the transformation will cause impact on the toxicity of heavy metal ions in soil. We explained the behavior of different metal ions based on the percentage of various speciation of heavy metal ions and inferred the transformation process of such metal ions in the passivation process. At the same time, based on Webber-Morris equation, the kinetic process during passivation process was discussed.