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1.
Huan Jing Ke Xue ; 34(9): 3669-74, 2013 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-24289021

RESUMO

Soil samples were collected from 18 sites at a relocated lead accumulator factory in the Southwest region, China. Among the 15 sample sites, profile soil samples at 0-20 cm, 20-40 cm and 40-60 cm were taken. Soil lead contents were analyzed by inductively coupled plasma-optical emission spectroscopy (ICP-OES). Characteristics of Pb in topsoil and soil profiles collected from different sampling sites were discussed. Results showed that: (1) The total Pb contents in topsoil (0-20 cm) ranged from 18.18 to 52,332.50 mg x kg(-1). The maximum content greatly exceeded the national standard (HJ 350-2007). The Pb concentration in different workshops followed a decreasing order: the fourth workshop > the second workshop > waste lead storage pit > sewage works > the third workshop > the fifth workshop > the first workshop > the original fourth workshop > the packing workshop > the office area. (2) Results of profile distribution showed that soil depth had no significant effect on Pb content. Lead can be highly accumulated at different depths of the soil, which was quite different from natural soils. (3) Hakanson's potential ecological risk index evaluation showed that there was widespread ecological risk in the soil of the plant, and serious ecological risk existed in some workshops where a large number of lead was enriched. Therefore, the site must be restored in order to reuse it.


Assuntos
Chumbo/análise , Poluentes do Solo/análise , Solo/química , China , Monitoramento Ambiental , Indústrias
2.
Huan Jing Ke Xue ; 34(9): 3679-83, 2013 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-24289023

RESUMO

In this research, six topsoil samples (0-20 cm) were collected in the heavy-metal lead contaminated soil of one lead battery factory in south-west China as research object, which were later divided into seven particle size fractions, and analyzed for the lead concentration as well as the correlation between the lead concentration and the organic matter content. The result showed that five soil samples were contaminated with lead with different pollution levels, and there were two different trends in the changes of lead concentration as of the change of soil particle size. The lead concentration of the three samples from sewage treatment workshop, the workshop A and the workshop B, showed a first declining and then ascending trend with the decreasing particle size. The lead concentration of the soil samples of the packing workshop and the former production workshop A showed a decreasing trend when the particle size decreased. The lead concentration and the organic matter content showed a positive linear correlation (R2 = 0.8232). Soil organic matter has the ability of lead enrichment, and the ability declines with the decreasing particle size. Soil texture may be an important factor for the interaction between soil organic matter and lead distribution.


Assuntos
Chumbo/análise , Tamanho da Partícula , Poluentes do Solo/análise , Solo/química , China , Indústrias
3.
Huan Jing Ke Xue ; 34(9): 3697-703, 2013 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-24289026

RESUMO

Lead-contaminated soil with different pollution load in a lead battery factory in the southwest of China was chosen as the research object, the lead content and speciation were analyzed, and different washing agents were screened. The lead washing efficiency and lead speciation were analyzed under different pH conditions, and the soil of different particle size was washed using different duration to determine the best washing time. The results showed that the soil of sites A and B in the factory was severely contaminated, the lead concentration reaching 15,703.22 mg x kg(-1) and 1747.78 mg x kg(-1), respectively, and the proportion of the active-state lead was relatively high, while the residue state accounted for only 17.32%, 11.64%, 14.6% and 10.2%. EDTA and hydrochloric acid showed the best extraction effect in the 5 washing agents tested, which included EDTA, hydrochloric acid, citric acid, rhamnolipid and SDS. Cleaning under acidic conditions could not only effectively extract the total amount of lead but also effectively reduce the environmental risk of active-state lead. pH 4-7 was suggested as the most appropriate condition. The cleaning effect of coarse sand and fine sand was good, while for washing powder clay, it is better to improve the process, with the optimal washing time determined as 240 min.


Assuntos
Recuperação e Remediação Ambiental/métodos , Chumbo/química , Poluentes do Solo/química , Solo/química , China , Ácido Cítrico , Ácido Clorídrico , Indústrias , Tamanho da Partícula , Dióxido de Silício
4.
Huan Jing Ke Xue ; 34(9): 3704-8, 2013 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-24289027

RESUMO

This research chose five lead-contaminated sites of a lead-acid battery factory to analyze the speciation distribution and concentration of lead. Under the same conditions (0.1 mol x L(-1) EDTA,30 min, 25 degrees C), the removal effect of heavy metal was compared between ultrasonic-assisted chemical extraction (UCE) and conventional chemical extraction ( CCE), and the variation of lead speciation was further explored. The results showed that the lead removal efficiency of UCE was significantly better than CCE. The lead removal efficiency of WS, A, B, C and BZ was 10.06%, 48.29%, 48.69%, 53.28% and 36.26% under CCE. While the removal efficiency of the UCE was 22.42%, 69.31%, 71.00%, 74.49% and 71.58%, with the average efficiency higher by 22%. By comparing the speciation distribution of the two washing methods, it was found that the acid extractable content maintained or decreased after UCE, whereas it showed an increasing trend after CCE. The reduction effect of the reducible was as high as 98% by UCE. UCE also showed a more efficient reduction effect of the organic matter-sulfite bounded form and the residual form. Hence, it is feasible to improve the washing efficiency of heavy metal contained in soil by conducting the cleaning process with the help of ultrasonic wave, which is a simple and fast mean to remove lead from contaminated sites.


Assuntos
Recuperação e Remediação Ambiental/métodos , Chumbo/química , Poluentes do Solo/química , Solo/química , Ultrassom , Ácidos , Indústrias
5.
Huan Jing Ke Xue ; 34(9): 3709-15, 2013 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-24289028

RESUMO

Attrition scrubbing was used to remediate lead contaminated-site soil, and the main purpose was to remove fine particles and lead contaminants from the surface of sand. The optimal parameters of attrition scrubbing were determined by orthogonal experiment, and three soil samples with different lead concentration were subjected to attrition scrubbing experiments. The results showed that the optimal scrubbing parameters were: a solid ratio of 70% dry matter, a temperature of 25 degrees C, an attrition time of 30 min, and an attrition speed of 1200 r x min(-1). Before attrition scrubbing, the screening and analysis of soil showed that in all three soil samples, lead was mainly enriched on sand and fine particles, and the distribution of lead was highly correlated to the organic matter. After attrition scrubbing, the washing efficiency of the original state lead contaminated sand soil in triplicates was 67.61%, 31.71% and 41.01%, respectively, which indicates that attrition scrubbing can remove part of the fine soil and lead contaminants from the surface of sand, to accomplish the purpose of pollutants enrichment. Scanning electron microscopy (SEM) analysis showed that the sand surface became smooth after attrition scrubbing. The results above show that attrition scrubbing has a good washing effect for the remediation of lead contaminated sand soil.


Assuntos
Recuperação e Remediação Ambiental/métodos , Chumbo/química , Poluentes do Solo/química , Solo/química , Dióxido de Silício
6.
Huan Jing Ke Xue ; 34(1): 401-8, 2013 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-23487968

RESUMO

Constructed wetlands as a wastewater eco-treatment technology are developed in recent decades. It combines sewage treatment with the eco-environment in an efficient way. It treats the sewage effectively, and meanwhile beautifies the environment, creates ecological landscape, and brings benefits to the environment and economics. The unique advantages of constructed wetlands have attracted intensive attention since developed. Constructed wetlands are widely used in treatment of domestic sewage, industrial wastewater, and wastewater from mining and petroleum production. However, many problems are found in the practical application of constructed wetland, e. g. they are vulnerable to changes in climatic conditions and temperature, their substrates are easily saturated and plugged, they are readily affected by plant species, they often occupy large areas, and there are other problems including irrational management, non-standard design, and a single function of ecological service. These problems to a certain extent influence the efficiency of constructed wetlands in wastewater treatment, shorten the life of the artificial wetland, and hinder the application of artificial wetland. The review presents correlation analysis and countermeasures for these problems, in order to improve the efficiency of constructed wetland in wastewater treatment, and provide reference for the application and promotion of artificial wetland.


Assuntos
Eliminação de Resíduos Líquidos/métodos , Gerenciamento de Resíduos/métodos , Áreas Alagadas , Biodegradação Ambiental , Arquitetura de Instituições de Saúde , Eliminação de Resíduos Líquidos/economia , Eliminação de Resíduos Líquidos/instrumentação
7.
Ying Yong Sheng Tai Xue Bao ; 18(9): 2013-8, 2007 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-18062305

RESUMO

There are many difficulties in ascertaining the area that needs to be remedied in contaminated site. This paper integrated the experts' judgments with grids as the sampling strategy in an abandoned pesticide plant in northern China, and applied a geostatistical method, inverse distance weighted interpolation (IDW), to simulate the pollutants- and risk spatial distribution. Based on soil environmental benchmark, two scenarios were designed for ascertaining the polluted area. The results showed that the area needed to be remedied and determined by IDW was somewhat larger, according to the national environmental 2nd standard for agricultural soils, but the area and cost needed for remedy were smaller and more economic and reasonable, based on the health risk threshold level and IDW method. A combination of IDW and health risk assessment in ascertaining polluted area would be a new way for site assessment and soil remediation in the future.


Assuntos
Monitoramento Ambiental/métodos , Saúde Pública/métodos , Poluentes do Solo/análise , Monitoramento Ambiental/estatística & dados numéricos , Resíduos Perigosos/análise , Matemática , Saúde Pública/estatística & dados numéricos , Medição de Risco
8.
Ying Yong Sheng Tai Xue Bao ; 18(8): 1869-76, 2007 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-17974259

RESUMO

Ecological risk is a hotspot in the present environmental management study, which mainly focuses on the chemical, physical, and biological stressors that may damage ecosystem or its components. Ecological risk assessment (ERA) has a great significance for making scientific environmental management strategies. In order to lessen the damage of ecosystem or its parts, and to manage the ecosystem effectively, it is necessary to predict the probability the adverse ecological effects would occur and the consequences. This paper summarized the research methods, tools and trends of ERA, and pointed out the areas that need to be further studied. It was suggested that under the background of urbanization, urban ecological risk should be given more attentions. The prospects of further study were discussed, based on the issues existed in current researches.


Assuntos
Ecologia , Exposição Ambiental/análise , Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Animais , Exposição Ambiental/efeitos adversos , Exposição Ambiental/prevenção & controle , Humanos , Modelos Biológicos , Medição de Risco
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