Gan W.-J.,Nanjing Institute of Environmental Sciences |
Gan W.-J.,Economic and Trade Service Center |
Gan W.-J.,State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control |
He Y.,Nanjing Institute of Environmental Sciences |
And 7 more authors.
Journal of Ecology and Rural Environment | Year: 2012
Soil samples were collected from a heavily contaminated zone in an electroplating plant site for stabilization test using biochar derived from straw. Variation of the heavy metals in amount and form with the rate of biochar amended into the soil was analyzed. Results show that biochar changed the forms and distribution of heavy metals in the soil and had some significant effect stabilizing the polluted soil, particularly on Cr. With increasing biochar amendment rate, the content of residual form of Cr increased significantly. Especially in the treatment of 100 g * kg-1 biochar, the content of residual Cr increased by 59. 51 mg * kg 1, as compared with that in CK (1 098. 75 mg * kg 1), being the largest increment. The effect of stabilizing Cu and Ni was closely related to biochar amendment rate: when biochar was added up to or over 70 and 30 g * kg 1, its remediation effect on Cu and Ni was quite obvious, but not on Zn in the soil. When biochar amendment rate was 50 g * kg 1, the total content of the 4 heavy metals (Cu, Cr, Ni and Zn) in residual form increased up to 1 805. 95 mg * kg 1, much higher than 1 745 mg * kg 1 in CK. The biochar amendment rate was quite reasonable.
Wang G.-Q.,Nanjing Institute of Environmental Sciences |
Wang G.-Q.,State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control |
Lin Y.-S.,Nanjing Institute of Environmental Sciences |
Lin Y.-S.,State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control
Journal of Ecology and Rural Environment | Year: 2014
Environmental standards are important bases for implementing environmental management. The current China National Soil Environmental Quality Standards (GB 15618-1995) is far from adequate to meet with the practical needs of soil environment management. Therefore, it is now urgent and necessary to develop a suitable SESV framework. In the light of the nation's soil environmental policies, i.e. "Exerting strict control over generation of new soil pollution", "delineating priority areas for soil environmental protection", "strengthening control of environmental risks of contaminated soils", and "unfolding soil pollution control and remediation", analysis was done of key tasks in protection and integrated management of soil environment and urgent needs for development of a SESV framework in China. Furthermore, based on surveys, a review was presented of status quo of the developed countries and regions and their experiences in the field of soil environmental laws/regulations and SESV frameworks. On such a basis, a proposal on soil environment standard system of China was brought forth, including soil environmental quality standards, soil environmental risk control standards, and polluted-soil-specific soil management and remediation (objective) standards. Meanwhile, suggestions were made that different soil environment supervisory institutions specific to "old" and "new" contaminated soils should be established separately. This research is expected to provide some references for the establishment and consummation of the SESV framework of China. © 2014, China Environmental Science Press. All rights reserved.
Li Q.,Nanjing Agricultural University |
Li Q.,Nanjing Institute of Environmental Sciences |
Li Q.,State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control |
Zhang S.,Nanjing Institute of Environmental Sciences |
And 8 more authors.
Chinese Journal of Environmental Engineering | Year: 2013
This study investigated the removal efficiency of organochlorine pesticides (OCPs), including heptachlor, chlordane and mirex, from soil washing effluent by micro Cu/Fe bimetallic particles. Nonionic surfactant triton X-100 (TX-100) was used as the solubilizing agent. Various factors including initial concentration of OCPs, solution pH, the amount of added micro Fe0 and Cu loading were examined. Batch experiments demonstrated that micro Cu/Fe could effectively remove OCPs from the washing effluent. The greatest reduction of OCPs from the washing effluent of soil No. 2 was achieved under the application of 1.0 g (25 g/L) micro Fe0 with 1.0% Cu loading, and solution pH of 6.89.The maximum removal rate of heptachlor, γ-chlordane, α-chlordane and mirex were 100.0%, 99.3%, 80.8% and 71.1%, respectively. Moreover, lower initial concentration of OCPs and higher dosage of micro Fe0 led to higher degradation rate of OCPs. Slightly acid condition was beneficial to the degradation of γ-chlordane and mirex, but the degradation rate of α-chlordane was higher at pH 6.89 than at pH 5.29 or pH 9.18.For soil No. 2 washing effluent, the optimal Cu loading amount was 1.0%, while for soil No. 1 washing effluent, the optimal Cu loading amount was 2.0%.
Zheng L.,Nanjing Institute of Environmental Sciences |
Zheng L.,State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control |
Lin Y.,Nanjing Institute of Environmental Sciences |
Lin Y.,State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control |
And 6 more authors.
Chinese Journal of Applied and Environmental Biology | Year: 2012
In order to provide method and data for monitoring, eco-toxicological diagnosis and remediation of contaminated soil, the acute toxicological effects on earthworms, as well as seed germination rates and root elongation rates of four selected plants (wheat, cabbage, corn and rice) were studied using chlordane and mirex-contaminated soil. The results showed that the response of earthworm to the contaminated sites was very sensitive and the mortality increased with chlordane and mirex concentration increasing. The earthworm death appeared at the third day and the mortality of some high concentration treatment groups reached 100% at the 14th day. Under the same concentrations of chlordane and mirex in the soil, root elongation rates were significantly inhibited and more sensitive than seed germination rates of the four species. The order of seed germination sensitivity was wheat > Chinese cabbage > rice > corn. As pesticides, chlordane and mirex toxicity to soil animal (earthworms) was greater than the toxicity to plants. The results suggested that the acute toxicity on earthworms could be used to indicate the contamination level of the industrial sites polluted by chlordane and mirex. The recommended test period was 14 days.
Yin F.-X.,Nanjing Institute of Environmental Sciences |
Yin F.-X.,Taizhou Polytechnic College |
Yin F.-X.,State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control |
Yin F.-X.,Yangzhou University |
And 7 more authors.
Huanjing Kexue/Environmental Science | Year: 2011
An experiment study has been carried out to investigate effects of the diameter of soil columns, the size of soil particulate and different contaminants on efficiency of simulated soil vapor extraction (SVE). Experiments with benzene, toluene, ethylbenzene and n-propylbenzene contaminated soils showed that larger bottom area/soil height (S/H) of the columns led to higher efficiency on removal of contaminants. Experiments with contaminated soils of different particulate size showed that the efficiency of SVE decreased with increases in soil particulate size, from 10 mesh to between 20 mesh and 40 mesh and removal of contaminants in soils became more difficult. Experiments with contaminated soils under different ventilation rates suggested that soil vapor extraction at a ventilation rate of 0.10 L·min -1 can roughly remove most contaminants from the soils. Decreasing of contaminants in soils entered tailing stages after 12 h, 18 h and 48 h for benzene, toluene and ethylbenzene, respectively. Removal rate of TVOCs(Total VOCs) reached a level as high as 99.52%. The results of the experiment have indicated that molecule structure and properties of the VOCs are also important factors which have effects on removal rates of the contaminants. Increases in carbon number on the benzene ring, decreases in vapor pressure and volatile capability resulted in higher difficulties in soil decontamination. n-propylbenzene has a lower vapor pressure than toluene and ethylbenzene which led to a significant retard effect on desorption and volatilization of benzene and ethylbenzene.
Ji H.,Nanjing Southeast University |
Long T.,Nanjing Institute of Environmental Sciences |
Long T.,State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control |
Chen Q.,Nanjing Institute of Environmental Sciences |
And 8 more authors.
Huagong Xuebao/CIESC Journal | Year: 2016
In this study, the capabilities of typical non-ionic surfactant Tween 80 and activated sodium persulfate for the oxidation of polycyclic aromatic hydrocarbons (PAHs) in soil were investigated. The mean PAHs desorption efficiency of 37.8% was obtained when 10% (20 g·L-1) Tween 80 was used and it increased to 89.5% after 4 times of soil washing. When citrate complexed ferrous sulfate was chosen as an activator and the Fe(II) concentration increased from 0.84 mmol·L-1 to 4.2 mmol·L-1 coupled with 84 mmol·L-1 SPS, the PAHs degradation efficiency increased from 64.3% to 73.5%. However, the PAH removal efficiency would then be suppressed if the Fe(II) concentration was continuously elevated. When SPS to Fe(II) molar ratio was fixed as 20: 1, the increase of the SPS concentration up to 168 mmol·L-1 caused as high as 86.1% of the total PAHs removal rate, which would not be further enhanced with increasing SPS concentration. The presence of 0.25% Tween 80 would increase the PAHs removal rate by 14%. The optimization results showed that the PAHs removal rates of as high as 90.0% could be achieved when the concentrations of Tween 80, SPS, and Fe(II) were 0.25%, 42 mmol·L-1 and 2.1 mmol·L-1, respectively. Thus, the activated SPS can be applied to effectively oxidized and removed soil PAHs and the efficiency can be improved with the addition of Tween 80. The Tween 80 coupled SPS oxidation will be an effective technique for PAHs removal from soil. © All Right Reserved.
Chen R.,Nanjing Southeast University |
Zhu X.,Nanjing Institute of Environmental Sciences |
Zhu X.,State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control |
Lin Y.,Nanjing Institute of Environmental Sciences |
And 4 more authors.
Huagong Xuebao/CIESC Journal | Year: 2015
Due to the high toxicity, potential of biological accumulation, recalcitrance to degradation and the known carcinogenic/teratogenic/mutagenic effects, the chlorinated organic compounds have been listed as priority controlled pollutants by the United States Environmental Protection Agency (EPA). In view of chlorinated pollutants contaminated sites, the traditional physical, chemical and biological remediation methods often impose relatively high costs and considerable impacts on the surrounding environment. The monitored natural attenuation (MNA) is an effective technology for site remediation and management and has been widely used internationally, which gradually attracts more and more attentions in China in recent years. It relies on the intrinsic potential of the pollutants to degrade naturally to meet the remediation requirements, and thereby would reduce treatment costs and lower on-site project risks. This paper focuses on the introduction of MNA technology, as well as the characteristics of chlorinated organic compounds such as the biodegradation pathways and mechanisms during the process of natural attenuation, the main degradation microbial communities and the key biodegradation enzymes. A preliminary discussion on the suitability of implementing MNA remediation on chlorinated organic compounds contaminated sites is provided. ©, 2015, Chemical Industry Press. All right reserved.
Wan J.,Nanjing Institute of Environmental Sciences |
Wan J.,State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control |
Meng D.,Nanjing Institute of Environmental Sciences |
Meng D.,State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control |
And 13 more authors.
PLoS ONE | Year: 2015
This study investigated the performance of rhamnolipids-citric acid mixed agents in simultaneous desorption of lindane and heavy metals from soils. The capacity of the mixed agents to solubilize lindane, lead and cadmium in aqueous solution was also explored. The results showed that the presence of citric acid greatly enhanced the solubilization of lindane and cadmium by rhamnolipids. A combined effect of the mixed agents on lindane and heavy metals removal from soils was observed. The maximum desorption ratios for lindane, cadmium and lead were 85.4%, 76.4% and 28.1%, respectively, for the mixed agents containing 1% rhamnolipidsand 0.1 mol/L citric acid. The results also suggest that the removal efficiencies of lead and cadmium were strongly related to their speciations in soils, and metals in the exchangeable and carbonate forms were easier to be removed. Our study suggests that the combining use of rhamnolipids and citric acid is a promising alternative to simultaneously remove organochlorine pesticides and heavy metals from soils. Copyright: © 2015 Wan et al.