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Interaction effect of micro-and macro-organic on the biogeochemical function of the sediment and aquatic interface

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Journal of environmental Sciences 2006年第3期18卷 468-474页

作者： XIAO Xiang LIAO Ling ZHANG Xin-hua Guangzhou Environment protection Bureau Guangzhou 510032 China Guangzhou research institute of environmental protection Guangzhou 510620 China South China Botanical Garden Chinese Academy of Sciences Guangzhou 510650 China

Constructed stormwater infiltration basins have been broad applied in urban areas in terms of stormwater disposal and compensation of reduced groundwater recharge. However, stormwater derived from sediments accumulating in infiltration beds may act as a source of dissolved contaminants for groundwater. Concentrations of DO, NO3-N, NO2^--N, NH4^＋-N and PO4^3--P were monitored at multiple depth with time. The results showed that the occurrence of denitrificarion was restrained by sediments in term of no invertebrates. Under the conditions of invertebrates inoculated, the concentrations of DO, NO^3--N, NO2^＋-N, NH4^＋-N and PO4^3＋-P varied respectively with time and the occurrence of nitrification and mobilizing nitrate in the sediment. It is concluded that there exist the invertebrate activities such as building tubes and galleries and excreting faecal pellet which may increase water dispersion and enhance accessibility of nutrient, and stimulate microbial process effected in the sediment. Besides, the natural death and rot of worms were also found to be important factors of the invertebrate activities.

关键词： infiltration basins urban stormwater polluted sediments invertebrates effects

Determination of organic carbon in soils and sediments in an automatic method

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Journal of Groundwater Science and Engineering 2017年第2期5卷 124-129页

作者： LI Guo-ao YAN Lei CHEN Zhen-he LI Ye Beijing Municipal research institute of environmental protection National Engineering Research Center of Urban Environmental Pollution Control

Our automatic digestion device is applied in determining the quantity of organic carbon in the soils/sediments. Its operation process is simple. The reaction conditions are optimized; the complex pretreatments are automated; and a great number of samples can be analyzed at the same time. Comparison shows that the experiment using the device is safer and easier. The correlation coefficiency is greater than 0.999, indicating a good linear relationship. The relative standard deviations of three different concentrations are less than 5%. Standard addition recoveries of high and low concentration range between 94.7% and 100% and between 91.7% and 105% respectively. Method determination limitation(MDL) of this method meets the practical requirements. The device in this paper supports a compositive SOC determination method. Its advantages include improved time and labor efficiency, and accuracy. The device is widely used in the studies of agricultural science, carbon cycle, climate change and environmental protection.

关键词： Automatic digestion Soils Sediments Organic carbon

Optimization and Scheduling of Byproduct Gas System in Steel Plant

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维普期刊数据库

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Journal of Iron and Steel research International 2015年第5期22卷 408-413页

作者： Jing-hui YANG Jiu-ju CAI Wen-qiang SUN Jing-yu LIU State environmental protection Key Laboratory of Eco-industry Institute of Thermal and Environmental EngineeringNortheastern University

A mathematical model was proposed to optimize byproduct gas system and reduce the total cost. The scope and boundaries of the system were also discussed at the same time. Boilers and gasholders were buffer users to solve the fluctuation of byproduct gases. The priority of gasholders should be ranked the last. The allocation of surplus ga- ses among gasholders and boilers was also discussed to make full use of gases and realize zero emission targets. Case study shows that the proposed model made good use of byproduct gases and at least 7.8 ~//00 operation cost was re- duced, compared with real data in iron and steel industry.

关键词： iron and steel industry byproduct gas energy saving optimization scheduling

Restoration processes of pollution zones in Hanjiang River

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Journal of environmental Sciences 1996年第2期8卷 178-184页

作者： Shen Yunfen Tan Yuyun Feng Weisong Gu Manru (institute of Hydrobiology, Chinese Academy of Sciences, Wuchang 430072, China) He Chengying (environmental protection Station of Xiantao City ,China) Li Aiguo (environmental protection Station of Xiangfan Ci institute of Hydrobiology Chinese Academy of Sciences Wuchang 430072 China environmental protection Station Xiantao City China environmental protection Station Xiangfan City China

Two pollution zones in middle and lower reaches of Hanjiang River were selected for studying restoration processes. In each zones 6 stations were set up in upper stream of sewage outfall, 50m, 100 or 150m, 250 or 525m and 1250 or 3500m apart from the outfall. Chemical monitoring and microbial community biomonitoring were carried out simultaneously. Either the chemical monitoring or the biological monitoring proved the self-purification process of water body along with the increased distance from the sewage outfall. 4 biological parameters (species number of protozoa, percentage of phytomastigophora, diversity index and heterotrophy index) and parameter Seq of the colonization process all have statistically significant correlations with chemical comprehensive pollution indexes Pa and Pb.

关键词： restoration process microbial community biomonitoring river pollution zone.

Assessment, Composition and Possible Source of Organochlorine Pesticides in Surface Soils from rmqi, China

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Pedosphere 2015年第6期25卷 888-900页

作者： CHEN Min CHEN Li HUANG Ping School of environmental Science and Engineering of Sun Yat-Sen University Cnhomeland and environmental Co. Ltd. institute of Plant protection and environmental protection Beijing Academy of Agricultural and Forestry Science

Twenty-eight surface soil samples from 5 functional zones （park, traffic roadside, business/residential area, rural area, and industrial area） of Uruimqi, China were collected and analyzed for the concentrations of 14 organochlorine pesticides （OCPs）, such as 3 isomers of hexachlorocyclohexane （HCHs）（α-HCH, β-HCH, and γ-HCH）, 4 dichlorodiphenyltrichloroethanes （DDTs）（p,p′-DDT and its metabolites p, p′-DDD （1,1-dichloro-2,2-bis（p-chlorophenyl）ethane） and p,p′-DDE （1,1-dichloro-2,2-bis（4-chorophenyl）ethylene）, and o, p′-DDT）, and methoxychlor, aiming to survey the residue levels and compositions of these 14 OCPs, to identify possible sources of the OCPs, and to assess their potential risks to human health and the environment in surface soils of Ur/imqi. The concentrations ranged from non-detected to 30.86μg kg^-1 for HCHs （sum of α-, β-, and γ-HCH）, from non-detected to 40.03 μg kg^-1 for DDTs （sum of p, p′-DDT, p, p′-DDD, p, p′-DDE, and o, p′-DDT）, and from non-detected to 11.95 μg kg^-1 for methoxychlor. The total concentrations of the OCPs ranged from 16.40 to 84.86 μg kg^-1, with a mean of 41.89 ± 16.25 μg kg^-1. According to the measured concentrations and occurrence rates of the 14 OCPs, DDTs, HCHs, and methoxychlor were the most dominant compounds. Among the 5 functional zones, the total concentration of OCPs was in the order of rural area 〉 traffic roadside 〉 park 〉 business/residential area 〉 industrial area. The different compositions of DDTs and HCHs indicated that the residues of these compounds in most soil samples originated from historical application, besides slight recent introduction at some sampling sites. The results of Pearson correlation analysis showed that soil total organic carbon played an important role in the residue levels of HCHs, but such relationships were not found with DDTs or other OCPs. The soil quality of Uriimqi was classified as Class I based on the guidelines of the Chinese environmental Quality Standard for Soil （GB15618-199

关键词： dichlorodiphenyltrichloroethane (DDT) factor analysis hexachlorocyclohexane (HCH) methoxychlor residue level risk soil quality

Characterization of precipitation in the background of atmospheric pollutants reduction in Guilin: Temporal variation and source apportionment

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Journal of environmental Sciences 2020年第12期32卷 1-13页

作者： Ling Li Hong Li Liang Peng Yongshan Li Yi Zhou Fahe Chai Zhaoyu Mo Zhiming Chen Jingying Mao Wenxing Wang State Key Laboratory of environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China College of Chemistry and Chemical Engineering Southwest Petroleum UniversityChengdu 610500China Guilin environmental Monitoring Center Station Guilin 541002China Scientific research Academy of Guangxi environmental protection Nanning 530022China institute of environmental and Climate research Jinan UniversityGuangzhou 511443China environmental research institute Shandong UniversityQingdao 266237China

Rainfall samples were collected from three observation sites in Guilin from 2013 to 2017, and the chemical composition characteristics of precipitation and the contribution made by different ion sources were analyzed when atmospheric pollutants levels were reduced. The results showed that acid gas emissions and atmospheric pollutant concentrations continued to decline during the study period. However, the change in the volume-weighted mean p H at the three sites suggested that acid rain pollution was not alleviated and began to deteriorate after 2015. The continuing downward trend for alkaline neutralizing ions(Ca^(2+), NH_4^+) in precipitation indicated that the reduction in alkaline neutralizing substances in the atmosphere was an important factor that led to the deterioration in acid rain across Guilin. The principal component analysis and spearman correlation analysis indicated five sources of ions in precipitation. Quantitative assessment of these five sources indicated that fossil fuel combustion contributed the most ions concentration in precipitation at the three sites, followed by agriculture, terrestrial(crustal) sources, marine sources, and biomass burning. Long-distance airflow might affect the acidity, the electrical conductivity(EC), and ion concentrations in precipitation across Guilin. The airflow trajectory from the west and southeast directions corresponded to higher acidity and ion concentrations. According to the current air pollution control strategy planned by Guilin, reducing atmospheric coarse particles and NH_3 at the same time may potentially lead to further deteriorations in acid rain contents. Therefore, Guilin needs to develop more reasonable pollution prevention measures that synergistically control atmospheric pollutants and acid rain pollution.

关键词： Precipitation chemistry Characterization Source contributions Synergistic control Guilin

The impacts of base level and lithology on fluvial geomorphic evolution at the tectonically active Laohu and Hasi Mountains,northeastern Tibetan Plateau

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Science China Earth Sciences 2021年第6期64卷 906-919页

作者： Zhengchen LI Xianyan WANG Yang YU Huiping ZHANG Qi SU Xiaodong MIAO Huayu LU School of Geography and Ocean Science Nanjing UniversityNanjing210023China institute of Geology China Earthquake AdministrationBeijing100029China School of Resource and environmental Sciences Linyi UniversityLinyi276000China

Previous researches had emphasized tectonic impacts on the fluvial system at the tectonically active areas,while the effects of lithology and local base level change have received relatively rare *** we investigated fluvial landforms at different spatial scales,focusing on knickpoints and channel network reorganization from an area affected by the Haiyuan Fault in the northeastern Tibetan *** geomorphic indices,i.e.,drainage pattern andχanomalies,were calculated and *** results show that two regional radial drainages formed around the Laohu and Hasi *** the interior of the radial drainage,tributaries from the southeast side of the Laohu Mountain experienced near 180°direction *** interpret this as the gradual drainage capture originating from the height difference(~190 m)of the local base level between the two *** tributaries from the Hasi Mountain show alternating gorges and broad valleys controlled by ***,tectonic uplift and the lowering of base level(from the incision of the Yellow River)triggered an autogenic positivefeedback transition from parallel to dendritic drainage *** observations suggest that base level change and lithology play a crucial role in landscape evolution,even in a tectonically active region.

关键词： River piracy Base level Lithology Geomorphic index Haiyuan Fault Northeastern Tibetan Plateau

HIGH-ORDER BOUNDARY CONDITIONS FOR THE PROBLEMS OF LAPLACE EQUATION IN INFINITE REGION AND THEIR APPLICATION

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Applied Mathematics and Mechanics(English Edition) 1990年第11期11卷 1081-1086页

作者：黄河宁王发君 institute of Marine environmental protection State Oceanic Administration Dalian

The high-order boundary conditions for the problems cf Laplace equation in infinite region have been developed. The improvement in accuracy for numerical solution is achieved by imposing the high-order boundary conditions on the exterior boundarv of a reduced finite region in which the numerical method is used. So both the computing efforts and the required storage in computer are reduced. The numerical examples show that the 1st-order boundary condition approaches to the exact boundary condition and it is clearly superior to the traditional boundary condition and the 2nd-order boundary condition.

关键词： Laplace equation potential function boundary condition conformal transformation

Using DGT to Assess Cadmium Bioavailability to Ryegrass as Influenced by Soil Properties

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Pedosphere 2015年第6期25卷 825-833页

作者： SONG Ningning WANG Fangli MA Yibing TANG Shirong Qingdao Engineering research Center for Rural Environment Qingdao Agricultural University Centre for research in Ecotoxicology and environmental Remediation Agro-Environmental Protection InstituteMinistry of Agriculture School of Resources and Environment University of Jinan

A generally accepted method for predicting the bioavailability and transfer of cadmium(Cd) from soil to plants has not yet been established. In this study, the diffusive gradients in thin films(DGT) and conventional extraction methods for metal fractions were used to investigate how effective these methods were at predicting Cd bioavailability to ryegrass(Lolium perenne) and to assess whether these holistic variables were independent of the soil property variables. The influences of soil properties on the predictive capabilities of the different methods were evaluated using multivariate statistics. The Cd concentrations in the shoots and roots of ryegrass correlated more closely with the effective Cd concentration measured by DGT(CE), compared with those with soil total Cd, pore water Cd, and ethylenediaminetetraacetic acid disodium salt(Na2EDTA)- and acetic acid(HOAc)-extractable Cd. When soil properties were included in a stepwise multiple linear regression, Cd transfer to L. perenne was negatively influenced by p H and positively influenced by organic matter(OM). The multivariate statistics showed that the adjusted correlation coefficients for the plots involving soil total Cd, pore water Cd, and Na2EDTA- and HOAc-extractable Cd had been significantly improved after considering the influences of soil properties, which suggested that these methods were p H and OM dependent. For CE, the relationship was p H independent or only dependent in strongly acidic soils. These results suggested that the main soil factors affecting bioavailability had the lowest impact on the DGT technique. Therefore, the DGT technique provided significant advantages over conventional methods when assessing Cd bioavailability.

关键词： conventional extraction methods diffusive gradients in thin films effective Cd concentration organic matter pore water