[Distribution Characteristics, Source Analysis and Ecological Risk Assessment of Heavy Metals in the Typical Industry Reclaimed Soil].

To further explore the characteristics of heavy metal pollution and the ecological risk of typical industries in reclaimed soil, based on data from 315 different depth profiles of soil samples collected from 49 plots in Jiading District, Shanghai, the geo-accumulation index and potential ecological risk index were used to evaluate the contents and potential ecological risk of seven heavy metals, namely Cd, Pb, Cu, Zn, Ni, Hg, and As. The APCS-MLR receptor model and PMF positive matrix factorization model were employed to analyze the pollution sources. The results showed that:① except for As, the contents of other heavy metals in the soil of the study area exceeded the Shanghai soil background values to varying degrees. The contents of Cd, Pb, Cu, Zn, Ni, and Hg in the surface soil were 3.54, 2.34, 2.91, 1.20, 3.75, and 4.40 times the background values, respectively. The contents of heavy metals in the soil decreased with the increase in depth, and heavy metals were enriched to a certain extent in the surface soil, indicating that human activities had an impact on the distribution of heavy metals in the soil. ② The APCS-MLR and PMF receptor models identified four main sources of soil heavy metals in the study area. Source 1 (Cu, Zn, and Pb) was a mixture of metal products and automobile manufacturing, source 2 (Ni and Cd) was electroplating enterprises, source 3 (Hg) was mainly from chemical enterprises, and source 4 (As) was natural. The combined use of the two receptor models further improved the accuracy and credibility of source identification. ③ The geo-accumulation index in descending order was Hg(1.54)>Ni(1.32)>Cd(1.21)>Cu(0.96)>Pb(0.64)>Zn(-0.33)>As(-1.02). The potential ecological risk index showed that the comprehensive potential ecological risk index RI value in the study area ranged from 32.50 to 4 910.97, with a mean of 321.40, indicating a strong potential ecological risk. The pollution values of heavy metals Hg, Ni, and Cd in industrial site soil deserve further attention for re-development and utilization purposes.

[Distribution Characteristics and Source Apportionment of Polycyclic Aromatic Hydrocarbons in Atmospheric Deposition in Areas Adjacent to a Large Petrochemical Enterprise].

In order to explore the influence of polycyclic aromatic hydrocarbons (PAHs) emissions by petrochemical enterprises on the surrounding environment, atmospheric deposition samples of the PAHs were collected in the industrial and residential areas adjacent to a petrochemical enterprise from March 2017 to February 2018. Deposition fluxes and the composition of PAHs were studied. The source of PAHs was analyzed by a positive matrix factor (PMF) model. The results showed that the deposition fluxes of Σ15 PAHs ranged from 549 ng·(m2·d)-1 to 18845 ng·(m2·d)-1, with an average of 2712 ng·(m2·d)-1. The flux of Σ15 PAHs in the industrial area was 1.36 times greater than that in the residential area. The deposition fluxes of PAHs in winter and spring were higher than those in summer and autumn. The deposition flux was highest in January in the industrial area and lowest in October in the residential area. Phe, BbF, and Fla were the dominant monomers. There was noticeable difference of monomers between the industrial area and the residential area in summer and autumn. The monomers, such as BbF, BkF, and BgP, in the residential area were higher than those in industrial area, and the proportion of 5, 6 rings was higher, which indicated that traffic contributed more to the residential area; 3 ring PAHs in industrial area had a higher proportion, which pointed out that their main source was petroleum volatilization. Based on the quantitative source analysis, the PAHs in atmospheric deposition were mainly from traffic emissions, petroleum volatilization, and coal combustion. Three sources of PAHs accounted for 45.7%, 18.4%, 35.9%, and 46.3%, 21.4%, and 32.3%, respectively, in the industrial area and the residential area in winter and spring. In summer and autumn, the contribution of traffic sources to the residential area was as high as 65.2%, and the proportion of the petroleum source to the industrial area increased to 35.5%. Due to high-altitude emissions and favorable diffusion conditions, the coal combustion contribution was significantly reduced.

[Effects of Manure and Organic Fertilizer Application on Soil Microbial Community Diversity in Paddy Fields].

To investigate the effect of typical manure application on soil microbes in paddy fields, a field experiment on manure application in Chongming Island was carried out. The composition and variety of soil microorganisms in rice paddy fields were analyzed using high-throughput theory (CK), chicken manure (CM), pig manure (PM), and organic fertilizer (OF). The results showed that compared with CK, the application of organic manure increased soil organic matter (SOM), and the application of chicken manure significantly increased the soil ammonia nitrogen (NH4+-N) and total nitrogen (TN) contents (P<0.05). Soil microbial diversity in the PM group was significantly higher than that in the CK group (P<0.05), and the soil microbial community richness in the OF group was significantly higher than that in the CM group (P<0.05). pH, total phosphorus (TP), total nitrogen, and Pb were the important factors affecting the composition of soil microbial communities in paddy fields. The microbial community structure in the CM group was significantly different from those in the other three groups. Compared with CK, the OF group increased the relative abundance of Nitrospira, and the CM group significantly reduced the relative abundance of the denitrifying bacteria Ignavibacteriae (P<0.01) to 40.56%, but significantly increased the relative abundance of nitrifying bacteria Thauera(P<0.05) to 203.00%. The PM group significantly increased the relative abundance of ammoniated bacteria Armatimonadetes (P<0.05) to 57.51% and the anaerobic strain Anaerolinea to 102.00%. The application of chicken manure and pig manure significantly increased the relative abundance of pathogens Pseudomonas and Flavisolibacter (P<0.05), respectively, while the application of organic manure reduced the relative abundance of Flavisolibacter. Overall, the application of manure increased the abundance of bacteria involved in the nitrogen cycle of paddy soils and played a positive role in regulating the nitrogen balance in paddy soils. However, direct application of chicken manure and fresh pig manure increased the abundance of pathogenic bacteria, which had a certain degree of stress on the soil health in the paddy field.

[Comparison and Source Apportionment of PAHs Pollution of Runoff from Roads in Suburb and Urban Areas of Shanghai].

Rapid urbanization has driven surface runoff pollution in urban areas to a serious state. In particular, polycyclic aromatic hydrocarbons(PAHs)from road surface runoff has attracted wide attention. Two traffic roads in Shanghai (Caobao Road in an urban central area, and Jiajin Expressway in the suburbs) were identified as research objects. Runoff samples from these two traffic roads were collected for 7 rainfall events between 2007 and 2018. Then, the concentration characteristics and composition ratio of PAHs were analyzed. The differences in pollution sources of runoff PAHs from two types of traffic roads were identified based on characteristic ratio method and positive matrix factorization(PMF). The results showed that the geometric mean value (5539.2 ng·L-1) of 16 PAHs of runoff from Jiajin Expressway in the suburbs was 10 times greater than that from Caobao Road (548.1 ng·L-1), which was related to a higher truck traffic and a lower cleaning frequency on Jiajin Expressway. The benzo(a)pyrene(BaP)concentration on both roads exceeded the national emission standard, and the amount in the Jiajin Expressway was up to 21 times higher than the standard. There was no significant difference in the composition of PAHs of runoff between Caobao Road and Jiading Expressway, and 4-6 ring were dominant and responsible for 80% of total PAHs loads in both sites. Based on the analysis of the characteristic ratio method, the PAHs of runoff from Caobao Road mostly came from coal-fired sources and traffic sources, while that from Jiajin Expressway were mostly from fossil fuels, coal, and other traffic sources. Quantitative source analysis through PMF method showed that the primary sources of PAHs were gas and coal, accounting for 48.6%, followed by traffic emission sources (29.8%), and oil sources (21.7%). The contribution ratios of PAHs sources of runoff from Jiajin Expressway, sorted in descending order, are:traffic emission sources (38.5%), coal-fired sources (34.6%), oil sources (14.6%), and coking sources (12.6%). PAHs sources and contribution rates between urban and suburban roads are completely different. Gas and coal were the main sources of PAHs of runoff from Caobao Road, which was related to the high population density and relatively large gas consumption in the Xuhui District. Traffic emission was the main source of PAHs from surface runoff on Jiajin Expressway, which was related to the massive flow of coaches and trucks, and their higher PAHs emission compared to small cars. In addition, there are still coking sources of PAHs of runoff from Jiajin Expressway, which can be related to the massive industrial coal consumption in the Qingpu District.

[Composition and distribution characteristics of stable carbon isotope in typical riparian grassland ecosystem]. / å ¸åž‹æ»¨å²¸è‰åœ°ç”Ÿæ€ç³»ç»Ÿç¢³ç¨³å®šåŒä½ç´ ç»„æˆåŠåˆ†å¸ƒç‰¹å¾.

Plant-soil carbon stable isotope characteristics of riparian herbaceous ecosystem were ana-lyzed by measuring the δ13C value of plant tissues from four typical riparian herbaceous plants, which were Cynodon dactylon, Trifolium repens, Festuca arundinacea and Imperata cylindrical, and that of soil organic carbon (SOC) from different vertical depths along Dongfeng Port River in Qingpu District, Shanghai. The result showed that T. repens and F. arundinacea were C3 plants while C. dactylon and I. cylindrical were C4 plants. There was no significant difference between the δ13C va-lue of stem and leaf, litter and root of the four herbaceous plants. The surface SOC δ13C value of C3 and C4 plants strips showed different trends with soil depth, which could be related to the background SOC δ13C value, soil carbon stable isotope fractionation effect and plant root distribution depth as well. Plant input was the main source of SOC and the δ13C composition of plant organisms had direct effect on the SOC δ13C value. The δ13C value of plant components were significantly correlated with the δ13C value of SOC. The SOC content and δ13C value were significantly correlated in the four herbaceous plants strips. The SOC content and δ13C value showed linear negative correlation in C3 plant strips and linear positive correlation in C4 plant strips.