Table of Content

Volume 39 Issue 11
25 November 2023
Evaluation of Resource and Environment Carrying Capacity for Rural and Township Development: Framework, Indicators and Methods
SONG Yong-yong, WANG Chuan-sheng, XUE Dong-qian, HUANG Jing, DONG Chao-yang
2023, 39(11):  1375-1385.  doi:10.19741/j.issn.1673-4831.2022.0998
Abstract ( 100 )   HTML ( 17)   PDF (1097KB) ( 248 )  
References | Related Articles | Metrics
Scientific evaluation of the resource and environment carrying capacity for rural and township development is the basis and premise for rationally allocating the three functional spaces of "production-living-ecology", and promoting the rural and township coordinated development with resource and environmental protection. However, in terms of research on the assessment of resource and environment carrying capacity of rural and township development, due to the lack of systematic and logical self-consistent analysis framework and indicator system, the assessment and monitoring of resource and environment carrying capacity of rural and township development with regional differences, historical variability and system complexity are limited. In the process of implementing the strategy of rural revitalization and the land space planning, it is urgent to build an evaluation index system of resource and environment carrying capacity for the needs of rural and township development. Therefore, on the basis of summarizing the research results of rural and township development and resource and environment carrying capacity, the key concepts and the coordination relationship between rural and township development and resource and environment carrying capacity are explained, and the technical framework for evaluating resource and environment carrying capacity of rural and township development has been constructed. In addition, under the guidance of the principles of indicator system construction and indicator screening methods, a scientific, systematic and standardized indicator system was established for the background evaluation of resource and environment carrying capacity for rural and township development at macro scale, and for the calculation and coordination evaluation of the carrying capacity of resource and environment for rural and township development with different dominant function types at micro scale. The key indicator algorithms and the basis for the selection of main parameters are proposed. The research results are expected to provide theoretical and methodological basis for the assessment and management of regional resource and environment carrying capacity for rural and township development in China, and to provide scientific basis and technical support for promoting the coordinated rural and township development and resource and environment carrying capacity development in terms of territorial space division and classification.
The Coupling Coordination Degree of Ecological Environment and Urbanization in Ecological Civilization Demonstration Area Based on Remote Sensing Ecological Index and Compounded Night Light Index: A Case Study of the Yangtze River Delta
YAO Guo-hui, LI Hai-dong, WU Jing, WANG Nan, LIU Chen-wei
2023, 39(11):  1386-1398.  doi:10.19741/j.issn.1673-4831.2023.0131
Abstract ( 128 )   HTML ( 27)   PDF (5124KB) ( 209 )  
References | Related Articles | Metrics
The ecological civilization demonstration area includes the national ecological civilization construction demonstration area and the "Lucid Waters and Lush Mountains Are Invaluable Assets (as Two Mountains)" practice and innovation base, which focuses on the developing of an ecological economic system with industrial ecology and ecological industrialization as the mainstay, explores the path and model of realization of ecological product value, especially in rapidly urbanized areas. Taking 77 ecological civilization construction demonstration areas and 22 "Two Mountains" practice and innovation bases in the Yangtze River Delta (YRD) as the objects, the author utilized land use products, VIIRS, and MODIS data to construct remote sensing ecological index (RSEI) and compounded night light index (CNLI) to represent the ecological environment quality and urbanization level, respectively, and explored the level and spatiotemporal variability of ecological civilization demonstration construction in the YRD by using spatial superposition analysis and coupling coordination degree model. The results show as follow:(1) The distribution of ecological civilization demonstration area in the YRD is uneven, among which, the distribution of ecological civilization construction demonstration areas is more concentrated and dominated by plain terrain, while the "Two Mountains" practice and innovation bases are more dispersed and dominated by mountainous terrain. (2) The ecological land area of the ecological civilization demonstration area exceeds 70% and has a good environment foundation, among which the RSEI index of the "Two Mountains" practice and innovation base is higher than that of the ecological civilization construction demonstration area, and the ecological environment quality is superior, but it is more fragile. (3) The CNLI and its growth rate of the ecological civilization construction demonstration areas are higher than those of the "Two Mountains" practice and innovation bases, which has a higher urbanization level and development speed. (4) From 2017 to 2021, the coupling coordination degree between ecological environment quality and urbanization level of the ecological civilization construction demonstration areas and "Two Mountains" practice and innovation base showed an increasing trend, with an average increase of 10.55% and 8.90%, respectively, indicating that the ecological civilization construction has achieved certain results, with the highest coupling coordination degree at the junction of Jiangsu and Zhejiang Provinces.
Study on the Factors Influencing Ecological Environment Quality in Shaanxi Province in the Context of Rural Revitalization
YANG Yue, ZHAO Yu, YUAN Xue-feng, GAO Xue-mei
2023, 39(11):  1399-1409.  doi:10.19741/j.issn.1673-4831.2022.0783
Abstract ( 134 )   HTML ( 11)   PDF (13904KB) ( 88 )  
References | Related Articles | Metrics
The quality of the ecological environment often determines whether human society can achieve sustainable development or not. It is of practical importance to explore how and to what extent rural development affects the ecological environment to achieve regional rural revitalization and sustainable development. Taking Shaanxi Province as the research object and counties as the research unit, the remote sensing ecological index (RSEI) for a long time series was used to characterize the spatial and temporal changes and changing trends in ecological environment quality in the province. The factors influencing the quality and spatial differences in the ecological environment were explored with the help of spatial and temporal geographical weighted regression models. The study show that:(1) the overall changing trend of ecological environment quality from 2000 to 2020 was positive, with the RSEI value increasing from 0.483 3 in 2000 to 0.651 2 in 2020. The ecological environment quality grades were good and relatively good, with the percentage of areas increasing from 40.14% to 63.43%, which are concentrated in the mountainous areas of southern Shaanxi Province and Yan'an City. (2) The overall trend was a "rapid improvement → slow change for the better" from 2000 to 2020. The areas with an improved ecological environment are much larger than those with a degraded ecological environment. (3) The influence of the population, land, and industry factors on the ecological environment showed an obvious spatial variability. The main factors that affecting the influence mode were the proportion of forest land area, the proportion of rural settlement area, fertilizer use per unit area, and total mechanical power per unit area. It is suggested that a sub-regional, scientific, and rational rural revitalization policy should be formulated for the future development process to coordinate rural development and the ecological environment in Shaanxi Province.
Characteristics of the Spatial and Temporal Evolution of Agricultural Inputs and Its Association with Planting Structure Adjustment in Jiangxi Province
WEN Xiao-shan, FENG Ya-wen, DU Chao, HUANG Xiu-zhen, WANG Xiao-jun, XIE Jin-zhao
2023, 39(11):  1410-1420.  doi:10.19741/j.issn.1673-4831.2023.0360
Abstract ( 75 )   HTML ( 9)   PDF (2916KB) ( 132 )  
References | Related Articles | Metrics
The objective of this study is to analyze the spatial and temporal patterns of agricultural inputs in Jiangxi Province over a 30-year period and investigate their correlation with adjustments in planting structure. This research aims to establish a theoretical foundation for enhancing the quality and efficiency of agricultural production and mitigating non-point source pollution in the agricultural sector. The analysis was conducted using ArcGIS, the center of gravity model, and the structural equilibrium degree approach. Linear regression analysis was employed to examine the correlation between changes in agricultural planting structure and agricultural inputs. The findings indicate that:(1) The input of chemical fertilizers, pesticides and agricultural films in Jiangxi Province demonstrated an overall trend of increasing and then decreasing from 1992 to 2019. However, the input of chemical fertilizers and pesticides on farmland in Jiangxi Province has been significantly reduced since the implementation of a series of policies aimed at reducing the consumption of pesticides and fertilizers and improving their efficiency in 2015, and the input of chemical fertilizers and pesticides in 2020 decreased by 24.5% and 43.9%, respectively compared with that in 2015, but the slowing trend of agricultural film input in recent years is not obvious; (2) There is a clear pattern of spatial clustering in the intensity of fertilizer application throughout Jiangxi Province, with a general trend of aggregated distribution along Poyang Lake Basin, Fuhe River Basin and Ganjiang River Basin; the degree of pesticide input is generally higher in the northeast of Jiangxi Province; and plastic agricultural film usage was generally increasing and particularly prevalent in the eastern and southern areas of the province; (3) The restructuring of the plantation industry in Jiangxi Province is evident in the significant rise of orchard plantation area, which increased from 106.7 thousand hectares in 1992 to 427.8 thousand hectares in 2020, resulting in an increase in proportion from 2.1% to 7.6%. A more pronounced correlation exists between the expansion of orchard planting area and the utilization of agricultural films, in comparison to the application of chemical fertilizers and pesticides. This observation suggests a strong correlation between the expansion of fruit cultivation areas in Jiangxi Province and the concurrent rise in the adoption of agricultural films.
Farmers' Livelihood Resilience and Its Optimization Path in the Yellow Sea Wetland Heritage Area
MA Sui-sui, LI Chuan-wu, ZHANG Hua-bing
2023, 39(11):  1421-1429.  doi:10.19741/j.issn.1673-4831.2023.0472
Abstract ( 78 )   HTML ( 13)   PDF (1138KB) ( 54 )  
References | Related Articles | Metrics
The Yellow Sea Wetland Heritage Area is the first coastal wetland natural heritage in China. Under the background that the wetland habitat conservation becomes a focal point of development, the livelihoods of farmers in the vicinity of the heritage area face numerous challenges. Enhancing the livelihood resilience of these farmers is crucial for achieving wetland conservation and promoting collaborative development with neighboring communities. Taking the typical villages surrounding the Yellow Sea Wetland Heritage Area as a case for the study, an evaluation index system for farmers' livelihood resilience based on three dimensions:buffering capacity, self-organization ability, and learning capacity was developed. The key influencing factors were also identified by the Obstacle Degree Model, and based on which the optimization path of farmers' livelihood resilience was further put forward. The findings are as follows:(1) Overall, the livelihood resilience of farmers in the villages surrounding the Yellow Sea Wetland Heritage Area was relatively low. Buffering capacity was the highest, while self-organization ability and learning capacity were comparatively lower, with significant variations in livelihood resilience among different types of households. (2) Housing conditions, public service coverage, per capita agricultural area, family livelihood diversity, financial support and risk perception ability were the common influencing factors of farmers' livelihood resilience across various household types. (3) A systematic approach should be adopted to construct a pathway for enhancing livelihood resilience, which should be guided by the principles of "classification optimization, multi-sector collaboration, policy support, and farmer self-awareness". The research results can serve as valuable decision-making reference for advancing harmonious co-existence between humans and nature in the Yellow Sea Wetland Heritage Area and promoting high-quality rural development.
Resource Endowment, Hometown Identity and Farmers' Choice of Participation Methods in Village Environmental Governance
LI Yu-ke, LUO Xiao-feng, TANG Lin
2023, 39(11):  1430-1440.  doi:10.19741/j.issn.1673-4831.2023.0441
Abstract ( 67 )   HTML ( 5)   PDF (925KB) ( 44 )  
References | Related Articles | Metrics
It is important to clarify the preferences of rural residents in their choice of environmental management methods, because it can further increase the participation rate of farmer households in environmental management and to accelerate the construction of ecologically pleasant and beautiful villages. Based on 1 168 microscopic survey data in Hubei Province, a bivariate probit model was used to empirically analyse the intrinsic role of the relationship between resource endowment, hometown identity and farmers' choice of participation methods in village environmental governance. The results show that there were differences in farmers' preferences for participation in village environmental governance, with 10.70% of the farmers preferring to participate with money, 38.36% preferring to participate with contributing efforts, and 19.52% preferring to participate with both money and contributing efforts. The higher the level of education and income from work, the more the farmers prefer to participate with money; the lower the proportion of total household income and income from work, and the wider the social network, the more the farmers prefer to participate with contributing efforts; the higher the level of total household income, social trust and social prestige, the more the farmers prefer to participate with both money and contributing efforts. There is a positive moderating effect of hometown identity in the process of total household income influencing farmers' "willingness to pay" and labour force influencing farmers' "willingness to contribute effort" to participate in village environmental management, and hometown identity can promote the participation of the groups of farmers who have the ability to contribute money or efforts to participate but have not yet done so in village environmental governance. Accordingly, policy recommendations are proposed to promote farmers' participation in environmental governance. These include improving their household resource endowment, cultivating and strengthening their sense of hometown identity, accelerating rural economic development and developing group differentiated governance strategies.
The Effect and Influencing Factors of Multi-agent Collaborative Governance of Tea Farmers' Green Production Behavior
JI Jin-xiong, ZHUO Kai-bin, XIE Yi
2023, 39(11):  1441-1452.  doi:10.19741/j.issn.1673-4831.2022.1237
Abstract ( 78 )   HTML ( 3)   PDF (1173KB) ( 48 )  
References | Related Articles | Metrics
According to the theory of collaborative governance, an indicator system was constructed to measure the collaborative degree of multi-agent governance of tea farmers' green production behavior. A sample dataset of 872 cases from Anxi County, Wuyishan City and Fuding City, Fujian Province, were used to evaluate the collaborative effect of multi-agent collaborative governance of tea farmers' green production behavior and empirically analyze its influencing factors, where a collaborative degree model of compound system and a confirmatory factor analysis model were employed. Results show that:(1) The order degree of each subsystem in the multi-agent collaborative governance system of green production behavior among tea farmers in the research area is low and imbalance. (2) The multi-agent collaborative governance synergy degree of green production behavior among tea farmers in Anxi County, Wuyishan City and Fuding City is in the general collaborative form, and has not reached the optimal collaborative state. (3) The five dimensions of measurement indicators, namely, governance agent participation, governance object development, governance mechanism assurance, governance goal orientation and governance environment promotion, have a significant positive impact on the multi-agent collaborative governance effect of green production behavior among tea farmers, while variations exist among the five dimensions. Based on these findings, the following policy recommendations are put forward:harness the collaborative role of various governance agent, enhance the participation level of governance in the governance of green production behavior among tea farmers, improve the realization mechanism of multi-agent collaborative governance and ensure the efficient coordination of governance of green production behavior among tea farmers, improve the system structure of multi-agent collaborative governance and enhance the function of governance elements of green production behavior among tea farmers.
Analysis on the Ecosystem Trophic Structure and Energy Flow of Typical Small and Medium Rivers in Northern China on Ecopath Model
LU Hao-tian, HAO Zi-yao, LIU Meng-shuo, YU Lu-ji, FAN Peng-yu, LI Ya-hui
2023, 39(11):  1453-1463.  doi:10.19741/j.issn.1673-4831.2022.0881
Abstract ( 89 )   HTML ( 12)   PDF (1878KB) ( 212 )  
References | Related Articles | Metrics
There are a number of small and medium-sized rivers throughout China, which are the closest to humans. But they are also affected by man-made transformation and production and life activities and show more obvious ecological degradation. Taking the Xuchang section of the Qingyi River as the study area, a mass-balance food web model was established with "Ecopath with Ecosim" according to the data of aquatic organisms collected in the summer and autumn of 2021. The achieved results reveal that the Qingyi River ecosystem mainly consists of five integrated nutrient levels (1.00-3.29), and due to the low transfer efficiency of trophic levels I and II, the energy flow to the higher nutrient level was seriously hindered, and the conversion efficiency of the whole system was only 1.08% and 1.82%. The mixed trophic impacts did not alter in summer and autumn, and predators except Culter alburnus exhibited a strong inhibitory effect on the bait organisms. A comprehensive analysis of multiple indicators, including parameters close to maturity, resilience and stability of the system, indicate that the total flow rates of the Qingyi River ecosystem were 2 571.06 and 1 472.58 t·km-2 in summer and autumn, respectively, and the size of the ecosystem in summer is greater than that in autumn and Finn's cycling index (FCI) and Finn's mean path length (FML) also revealed that the ecosystem maturity and stability in summer were superior to those in autumn. Finally, according to the food web model, three key functional groups at various nutrient levels in the Qingyi River ecosystem have been selected as phytoplanktons, molluscs, and Culter albus, while maintaining the appropriate requirements of key functional habitats and growth habits, the pertinent suggestions for restoring the ecosystem, such as limiting the growth of dominant phytoplankton species, increasing mollusk predator pressure, and restoring the Culter alburnus population are presented. The findings of this study could provide decision-making basis and scientific support for the ecological restoration of the Qingyi River and similar rivers.
Spatiotemporal Distribution and Variation Trend of Rainfall Erosivity in the Nandu River Basin
LU Xu-dong, QI Shi, CHEN Jia-dong, GUO Jian-chao, ZHANG Lin, ZHOU Piao
2023, 39(11):  1464-1473.  doi:10.19741/j.issn.1673-4831.2022.0894
Abstract ( 71 )   HTML ( 5)   PDF (2362KB) ( 133 )  
References | Related Articles | Metrics
Rainfall erosivity is an important index used to characterize the intensity of rainfall erosion, which is of great significance to the research on potential risk of soil erosion in the study area and for model predictions. To analyze the spatiotemporal variation trend of rainfall erosivity in the Nandu River Basin, based on the daily rainfall erosivity model, daily rainfall data recorded at 13 meteorological stations in the basin and its surrounding areas from 1971 to 2020 were used to systematically study the rainfall erosivity at different spatiotemporal scales. The research methods included the application of the Mann-Kendall nonparametric trend/mutation test, wavelet analysis, and inverse distance weighted interpolation to determine the spatiotemporal variation trends of rainfall erosivity. The results show that the average annual rainfall erosivity in the Nandu River Basin from 1971 to 2020 ranged from 11 841.33 to 23 692.14 MJ·mm·hm-2·h-1, with an average value of 16 497.67 MJ·mm·hm-2·h-1, and the interannual variations reflect four stages, with an overall trend of rising fluctuations. The results indicate that the potential risk of soil erosion increased gradually over the study period. The annual rainfall erosivity has a change cycle of 30 years, and no obvious abrupt change occurred during the study period. Affected by the monsoon climate, latitude, elevation, spatiotemporal distribution of rainfall erosivity and erosive rainfall distribution, the rainfall erosion force was mainly concentrated in the period from July to September, accounting for 51.26% of the annual rainfall erosivity. Therefore, it is necessary to strengthen the prevention and control of soil erosion in this period, especially when rainfall erosivity peaks in August. Rainfall erosivity showed upward trends in summer, autumn and winter, but in spring, rainfall erosivity showed a downward trend. The spatial distribution of the annual rainfall erosivity decreased gradually from south to north. The variation coefficients of the meteorological stations ranged from 0.24 to 0.43, showing high regional variability. The variation coefficient of the northern region was relatively large, while that of the southern region was relatively small, and the overall trend gradually decreased from north to south. Rainfall erosivity in the Nandu River Basin was significantly and positively correlated with the erosive rainfall and elevation; and the erosive rainfall effect passed the significance test at 0.01, while the elevation effect passed the significance test at 0.05. Certain correlations were found between rainfall erosivity and both latitude and longitude, with correlation coefficients of 0.76 and 0.42, respectively, both passing the 0.01 significance test. This study can provide a reference for the prediction and control of soil and water losses and the envirommental protection in the Nandu River Basin and related typical erosion areas.
Effect of Shutdown/Restart Operation on Water Treatment Performance and Microbial Flora Characteristics for Two-stage Anoxic-aerobic Setup
YANG Zhe, ZHOU Xiao-guo, LI Yan, WANG Ming-liang, ZHU Li, ZHU Hua, MAO Xu-hui
2023, 39(11):  1474-1482.  doi:10.19741/j.issn.1673-4831.2022.1246
Abstract ( 89 )   HTML ( 7)   PDF (1760KB) ( 34 )  
References | Related Articles | Metrics
Rural leisure tourism sewage has the characteristics of discontinuous discharge and large fluctuation with time, which poses a great challenge to the management and operation of decentralized sewage treatment equipment. In this study, a two-stage AO-MBR setup is designed, which uses simulated sewage as the inlet water. Through the operation mode of shutdown/restart in different time periods, the impact of shutdown on the biochemical performance and recovery of the treatment process was explored. The results show that the shutdown operation had a significant impact on the biochemical treatment efficiency of the experimental setup, and the decline degree of biochemical treatment efficiency and the recovery time had a significant correlation with the shutdown time of the setup. As the shutdown time was extended from 1 d to 8 d, the COD removal efficiency could be decreased from 90% to 80%, and the longest recovery time was up to 5 d; the removal efficiency of ammonia nitrogen could be decreased from 90% to around 70%, and the longest recovery time was up to 5 d; the total nitrogen removal efficiency could be decreased from 48% to 34%, and the longest recovery time of the system required 5 d too. From the perspective of sludge activity, with the extension of shutdown time, the sludge activity indexes such as SOUR, dehydrogenase activity and SATP decreased accordingly. Through the method of microbial sequencing, it was also found that the microbial population changed greatly before and after the shutdown. From the perspective of phylum level, the proportion of heterotrophic bacteria of Proteobacteria decreased significantly after the shutdown, and the proportion of anaerobic bacteria such as Bacteroidea increased. From the perspective of genus classification, the number of traditional nitrifying bacteria decreased, but the number of bacteria with synchronous nitrification and denitrification showed an upward trend. For the wastewater treatment facilities that have to be shut down, an aeration operation with less oxygen is a feasible alternative way to maintain the activity of the sludge.
Effect of Mulberry Stems Biochar on Immobilization of Cd, Pb and Zn in Redox Dynamic Soil
LIU Yi-han, LIU Ying, WANG Li-na, YANG Lu, DENG Shao-po, WEI Jing, MAO Meng
2023, 39(11):  1483-1491.  doi:10.19741/j.issn.1673-4831.2022.0955
Abstract ( 77 )   HTML ( 9)   PDF (1739KB) ( 167 )  
References | Related Articles | Metrics
Biochar, as a green and sustainable soil stabilization agent, has been widely used in the remediation of heavy metals (HMs) contaminated soil. The migration and transformation of HMs are highly affected by the physicochemical characteristics of soil. Under the change of redox process caused by flooding-drainage intercropping in paddy soils, the fluctuation of physicochemical characteristics of soil will threaten the long-term safety of land utilization. Here, a mulberry stem was selected as feedstock to produce biochar by the in situ "water-fire coupled" method. The derived biochar was noted as SG-BC. The capability and mechanisms of SG-BC adsorbing Cd, Zn, and Pb were investigated. The results show that the maximum adsorption capacities for Pb, Zn, and Cd of SG-BC were 214.39, 41.10, and 25.75 mg·g-1, respectively. The mechanisms were clarified as surface complexation, precipitation, and cation-π interactions. In addition, a soil microcosm incubation experiment was conducted under redox dynamic conditions to explore the impact of SG-BC on the soil Eh and pH, and the immobilization of HMs. The results show that compared to the control, the addition of SG-BC could increase soil pH, slightly decrease soil Eh, and inhibit the soil HMs release at various degrees during flooding, and the inhibition was more strong during drainage, especially in the early stage; SG-BC decreased the concentrations of Pb, Zn, and Cd in soil solution by 96.69%, 80.77%, and 78.41%, respectively. These results indicate that SG-BC is effective to immobilize Cd, Zn, and Pb in the soil with dynamic redox processes. This study provides theoretical basis for applying biochar to remediate HMs contaminated agricultural soil.
Effect of Lignite-based Modified Material Application on Calcareous Soil Agglomerates and Soil Cadmium Distribution
ZHAO Shao-guan, YANG Qiu-yun, DING Man, HUA Dang-ling
2023, 39(11):  1492-1503.  doi:10.19741/j.issn.1673-4831.2022.0731
Abstract ( 85 )   HTML ( 6)   PDF (1561KB) ( 144 )  
References | Related Articles | Metrics
The study aims to investigate the effects of application of the modified lignite on the distribution of typical northern calcareous soil aggregates and distribution of heavy metal cadmium (Cd) in different particle-size aggregates. Different types of modified lignite materials were introduced into soils contaminated with Cd, followed by a 150-day incubation period. Soil aggregates at different grain levels were extracted by dry sieving and wet sieving, and the contents of calcareous soil aggregates and heavy metal cadmium and their stability were investigated in response to different modified lignite application amounts (0, 1%, 3%, and 5%), and the distribution of different Cd forms in aggregates. The distribution of various forms of Cd in soil aggregates was analyzed across different particle size fractions. The results obtained from dry and wet sieving demonstrated a gradual increase in the content of water-stable aggregates in the soil due to the application of modified lignite. More specifically, the content of water-stable aggregates exhibited an increase ranging from 0.9% to 25.2%, 5.5% to 24.5%, 12.1% to 46.5%, 98.4% to 156.1%, and 127.8% to 174.4% under treatments of lignite (LI), lignite-based humic acid (LIH), demineralized lignite (LID), humic acid resin (HAR), and humic acid-grafted copolymer (HAG), respectively. The content of water-stable agglomerates, average weight diameter, geometric mean diameter and particle size greater than 0.25 mm agglomerates of the soil increased significantly after the application of amendment. Among the different treatments, the coefficient of enrichment of Cd in coarse sand-sized aggregates (r1) and fine sand-sized microaggregates (r3) exhibited higher enrichment factors, while the coefficient of enrichment of water-stable agglomerates at the grain level (r2) was the smallest. In conclusion, the application of modified materials can not only effectively increase the water-stable aggregates of soil, but also effectively enrich the ion exchange state, carbonate binding state and iron and manganese oxidation state in the aggregates larger than 0.25 mm and the water-stable micro-aggregates smaller than or equal to 0.053 mm. The strong organic, weak organic and residual Cd are enriched in the water-stable microaggregates smaller than or equal to 0.053 mm. Particularly, lignite-based humic acid and demineralized lignite exhibited the most favorable effects on the formation of water-stable aggregates and the enrichment of Cd.
Pollution Characteristics and Risk Assessment of Seven Phthalate Esters in Typical Chemical Industry Parks in Jiangsu Province
GU Wen, WANG Zhen, LIANG Meng-yuan, FAN De-ling, XING Wei-long, SUN Shuai, ZHANG Bing, WANG Lei, SHI Li-li
2023, 39(11):  1504-1514.  doi:10.19741/j.issn.1673-4831.2023.0143
Abstract ( 121 )   HTML ( 10)   PDF (1074KB) ( 137 )  
References | Related Articles | Metrics
This study aimed to evaluate the pollution characteristics and risks of phthalate esters (PAEs) in typical chemical industry parks in Jiangsu Province. Samples were collected of drinking water, surface water, raw water and effluent from sewage treatment plants, and soil and sediment from five chemical industry parks in Changzhou, Suzhou, Taizhou and Nantong in Jiangsu Province in December 2022. The concentrations of PAEs in the different samples were determined by gas chromatography-mass spectrometry. The main PAEs detected were bis(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), diisobutyl phthalate (DIBP), and di-n-octyl phthalate (DNOP). The total concentration ranges of PAEs in water, sediment, and soil were not from detected to 13 757 ng·L-1, 78.4 to 2 618 μg·kg-1, and 56.7 to 1 329 μg·kg-1, respectively. The average PAEs concentrations in water, sediment, and soil were 1 369 ng·L-1, 661 μg·kg-1, and 442 μg·kg-1, respectively. High concentrations of PAEs were detected in surface water and drinking water in Nantong and Taizhou, and in sewage treatment plant effluent in Taizhou. High concentrations of PAEs were also detected in soil and sediment in Nantong and Taizhou. The risk entropy method was used to assess the risk levels of the PAEs. The results show that PAEs in surface water, soil, and sediment in typical chemical parks in Jiangsu Province presented a moderate to high degree of risk. High risk was presented by PAEs in sewage treatment plants. A health risk evaluation show that the PAEs health risk entropy in drinking water and water sources around chemical industrial parks in Jiangsu Province ranged from 0 to 0.191 2. The PAEs in drinking water presented a moderate risk in Nantong and a low risk in other areas. Overall, samples from Nantong and Taizhou showed the highest levels of pollution and had risks that were above moderate levels; therefore, pollution in these areas should receive high attention. Further analysis is required to identify the sources of PAEs pollution in these areas so that effective measures can be taken to control excessive emission of such pollutants into the environment.