CHINA ENVIRONMENTAL SCIENCECE
 
 
CHINA ENVIRONMENTAL SCIENCECE
　　　　　　　　    More    
Online Submission
Manuscript Tracking
Peer Review
Editor Work
Office Work
Editor-in-chief
Forthcoming Articles
Current Issue
Archive
Advanced Search
Read Articles
Download Articles
Instruction
Template
Copyright Agreement
More   
  Current Issue
 
2010 Vol.30 Issue.10,Published 2010-10-20
1297 Typical forests’ leaching characteristics during acid rain in Guizhou
LI Jia, LI Wei, HOU Jin-Xiang, GAO Fang
From June 2007 to November 2008, the throughfalls of masson pine and mixed wood was collected and measured at Longli experimental plot in Guizhou province. The acidity and chemical composition of throughfalls were analyzed with statistical methods to reveal the leach characteristics and seasonal tendency of local acid rain. pH values of precipitation increased obviously after getting through the crowns, and mixed wood had a better cushioning effect against acid rain than masson pine. Under the action of acid deposition in the perennial, crowns of masson pine and mixed wood had a certain absorption of NH4+ and NO3-, which could mitigate local soil’s acidification. Acid rain induced nutrient ions such as Mg2+, K+ and Ca2+ to leach and lose.
2010 Vol. 30 (10): 1297-1302 [Abstract] ( 233 ) [HTML 1KB] [ PDF 352KB] ( 728 )
1303 The distribution and possible source of polycyclic aromatic hydrocarbons in dust from six air conditioner filters.
ZHOU Hong-Cang, ZHANG Cui-Cui, CAI Hua-Xia, SONG Yuan-Yuan, XUE Hong-Bin
GC-MS technique was applied to determine 16 priority-controlled polycyclic aromatic hydrocarbons (PAHs) in dusts from air conditioner filters under six different indoor environments. 16 priority-controlled PAHs were detected in dusts from six air conditioner filters with a significant difference in concentration and with the highest PAHs concentration of 13.090μg/g in the restaurant. The average concentration of PAHs in dusts from six air conditioner filters is 4.345μg/g. There are also significant differences in the single PAH concentration with the highest concentration of BaA, followed by Chr, and the concentration of AcP is the lowest. The ring number distribution of PAHs is similar in the six air conditioner filters, dominated by 4- and 5-ring PAHs with the average percentage of 38.3% and 28.3% respectively. The ratio of mass concentration of BaA to Chr is 0.680 in the living room and 1.564 in the restaurant, from which it can be judged that the two main sources of PAHs are the smoke of tobacco combustion and cooking respectively. The TEQs of PAHs have an obvious difference, and the TEQ of BaP accounts for an average of 55.7%.
2010 Vol. 30 (10): 1303-1308 [Abstract] ( 224 ) [HTML 1KB] [ PDF 389KB] ( 626 )
1309 Atmospheric nitrogen wet deposition and nitrogen volatilization in Chinese chive planting field of a typical agricultural area at northern bank of Dianchi Lake
LU Hai-Yan, HU Zheng-Yi, ZHANG Rui-Jie, YIN Xiao-Feng, FENG Yu-Wan, WU Yong-Hong
One–year monitoring study was conducted to estimate wet N deposition to in Chinese chive planting field of a typical agricultural area at northern bank of Dianchi Lake. Nitrogen volatilization was also investigated in soils of Chinese chive planting fields, in situ field Chinese chive decomposition, and in ditch sewage water. The total wet N deposition was 7.1kg N/hm2 in 2007, about 89% of N deposition occurred during the rainy season of April to September. The cumulative ammonia volatilization loss 35days after N fertilization accounted for 25% of supply N as urea (345 kg N/hm2), about 96% of ammonia volatilization loss occurred during the first 9days after N fertilization. The cumulative N volatilization loss accounted for 27%~38% of total N in the ditch sewage water containing 7~51mg N/L (2.7~25.8mg N/L as NH3-N) within open storage for 12days. Therefore, nitrogen volatilization in Chinese chive planting fields could be one of important sources of atmospheric nitrogen in the present investigation area.
2010 Vol. 30 (10): 1309-1315 [Abstract] ( 218 ) [HTML 1KB] [ PDF 482KB] ( 769 )
1316 Monitoring the dynamic process of nitrification with respirometry-titrimetry
ZHANG Xin, ZHANG Dai-Jun, LU Pei-Li, LOU Xiao-Dan, SONG Xue, LIN Ning-Bo
A set of automatically respirometric-titrimetric system to monitor simultaneously oxygen uptake rate(OUR)and hydrogen ion variation rate(HVR) was developed, which consists of the pH monitoring unit, titrant auto-dosing unit and hybrid respirometer. Timely sampling and measuring the NH4+-N concentration in the nitrifying process, the accuracy of the system for monitoring dynamic process of nitrification was evaluated by comparing the consistency between the measured NH4+-N concentration and the predicted concentration based on OUR and HVR respectively. For the batch experiments process with initial NH4+-N concentrations of 20 and 25 mg/L respectively, the correlation coefficients between the measured value and the predicted value based on OUR were 0.9967 and 0.9972, 0.9991 and 0.9992 between the measured value and the predicted value based on HVR, that showed that the dynamic process of nitrification could be timely and accurately presented with measuring OUR and HVR in the process.
2010 Vol. 30 (10): 1316-1322 [Abstract] ( 234 ) [HTML 1KB] [ PDF 605KB] ( 691 )
1323 The accumulation of nitrite nitrogen in biofilter for mariculture wastewater treatment and influencing factors.
ZHANG Yan-Qing, XU Yang, GAO Xi-Yan, LIU Zhi-Pei, ZHANG Shao-Jun, LIU Ying
The experiment studied the accumulation of nitrite nitrogen in biofilter packed with bamboo ring while treating Cynoglossus semilaevis mariculture wastewater with high salinity and low ammonia nitrogen loading. Some operating parameters were carried out, including influent organic loading, ammonia nitrogen loading, temperature, pH and dissolved oxygen as well as the denitrification to the influence of nitrite nitrogen accumulation. When the influent organic loading was 0.65~0.75kg/(m3×d), the ammonia nitrogen loading was 0.058~0.077kg/(m3×d), the temperature for 20.9~22.2℃, pH for 7.50~8.14℃ and the dissolved oxygen was under 7.43~9.73mg/L, the low dissolved oxygen in biofilter was the primary cause for nitrite nitrogen accumulation. Meanwhile, the influential factors on nitrite nitrogen accumulation were investigated, including the low dissolved oxygen, the carbon nitrogen ratio (C/N) and the carbon source type in the denitrification process. The denitrification process was potential to create nitrite nitrogen accumulation under the operating conditions. It was confirmed that the denitrification process was affected in the nitrite nitrogen accumulates through further study on nitrogen compounds concentration variation in the biofilter and the denitrifying bacteria. The conclusion showed clearly that the denitrification promoted the nitrite nitrogen accumulates.
2010 Vol. 30 (10): 1323-1332 [Abstract] ( 223 ) [HTML 1KB] [ PDF 500KB] ( 824 )
1333 UV photodegradation of p-tert-octyl phenol(4-OP) in water
WU Yan-Lin, YU Yan, YUAN Hai-Xia, DONG Wen-Bo
The degradation of p-tert-octyl phenol (4-OP) in a thin aqueous layer by 185 nm UV irradiation and its dependence on the initial concentration, thickness of the aqueous layer and light intensity were investigated. The 185 nm UV irradiation was proved to be effective for the removal of 4-OP in water. The rate of degradation was increased to more than 95% after the illumination for 45min when the initial concentration was 10mg/L, the thickness of the aqueous layer was 2mm and the distance from UV lamp was 10cm. The degradation reaction was found to accord with the characteristic of apparent first-order reaction.
2010 Vol. 30 (10): 1333-1337 [Abstract] ( 240 ) [HTML 1KB] [ PDF 427KB] ( 856 )
1338 Influence of treated wastewater reuse on variation of chlorophyll-a in community landscape water body
LI Chang, QIN Hua-Peng, Soon-Thiam Khu, WANG Bo
Treated wastewater provides potential water source for landscape water bodies in a community. However, these water bodies are at risk for developing algal blooms because of high nutrient levels of treated wastewater. Based on the data from water exchange experiment in an artificial landscape water body supplemented by treated wastewater, a eutrophication model was calibrated and validated. The model was furthermore applied to simulate chlorophyll-a variation in landscape water body during the period with continuous water exchange (period-1) and when water exchange was consequently suspended (period-2). Effects of treated wastewater quality and water exchange cycle on algae growth were analyzed. The results indicate that: improvement of treated wastewater quality may reduce the peak concentration of chlorophyll-a; in period-1, the shorter water exchange cycle period is, the lower peak concentration of chlorophyll-a the water body has, and the longer time it needs to reach the peak; in period-2, the concentrations of chlorophyll-a will reach peak again, however, the shorter water exchange cycle in period-1 is, the higher chlorophyll-a peak concentration the water body has, and the longer time it needs to reach the peak. The application of the model can provide support for design and daily maintenance of community landscape water body supplemented by treated wastewater.
2010 Vol. 30 (10): 1338-1343 [Abstract] ( 210 ) [HTML 1KB] [ PDF 506KB] ( 567 )
1344 A disposable cobalt-based phosphate sensor based on screen printing technology
ZHU Lei, ZHOU Xiao-Hong, SHI Han-Chang
A cobalt-based phosphate sensor was successfully fabricated by using the screen printing technology for the determination of phosphate concentration in the aqueous solution. The disposable sensor consisted of fully integrated cobalt (Co) electrode, which was a layer of carbon conductive ink (C) physically doped with Co powder, and Ag/AgCl reference electrode. At 25℃ and the Co/C ratio of 1:7, the cobalt-based phosphate sensor showed strong stability and phosphate-selective potential response was in the range of 1×10-5 mol/L to 10-1 mol/L, yielding a detection limit of 5×10-6 mol/L and a slope of -41.63 mV/decade in acidic solution (pH 4.0, potassium hydrogen phthalate buffer) for H2PO4-.The response time of the screen-printed electrode was about 60s. The proposed screen printed sensor also exhibited significant reproducibility with a small repeated sensing deviation (i.e. relative standard deviation (R.S.D.)< 1%) on a single sensor and a small electrode-to-electrode deviation(i.e. R.S.D.<3.5%).
2010 Vol. 30 (10): 1344-1348 [Abstract] ( 228 ) [HTML 1KB] [ PDF 347KB] ( 701 )
1349 Electrochermical determinnation of catechol with nano- gold/carbon nanotubes modified graphite electrode.
LUO Qi-Mei, LIU Deng-You, WANG Hui-Xian, ZHOU Hua, ZHOU Dong
Surface of carbon nanotubes (CNTs) supported gold (Au) nanoparticles was prepared by spontaneous reduction of HAuCl4 aqueous solution, and as-prepared Au-CNTs/C electrodes show high electrocatalytic performance for CAT. The electrochemical behaviors of Au-CNTs/C elecrodes were investigatated by cyclic votammetry. It was obtained a well-shaped redox reactin at Au-CNTs/C elecrodes, and oxidation peak of catechol was obviously observed at 0.25V. Additional, linear relationship was obtained between Ipa and concentration of catechol in the range of 5.0′10-7~ 5.0′10-3mol/L in phosphate buffer solution (pH 7.4), with a correlation coefficient of 0.9992, and the detection limit of this method was found to be 3.3′10-7mol/L.
2010 Vol. 30 (10): 1349-1352 [Abstract] ( 223 ) [HTML 1KB] [ PDF 544KB] ( 731 )
1353 Changes of dissolved organic matter in soil-aquifer treatment system.
XUE Shuang, ZHAO Qing-Liang, WEI Liang-Liang, LI Fa-Yun, MA Xi-Ping
The changes of fluorescence characteristics of dissolved organic matter (DOM) during laboratory-scale soil-aquifer treatment (SAT) soil columns were studied. Using XAD resins, DOM was fractionated into 5 fractions: hydrophobic acid (HPO-A), hydrophobic neutral (HPO-N), transphilic acid (TPI-A), transphilic neutral (TPI-N) and hydrophilic fraction (HPI). Aromatic protein-like fluorescent materials in TPI-N were preferentially removed during SAT. The raletive content of aromatic protein- and soluble microbial byproduct-like fluorescent materials in HPO-A, HPO-N, TPI-A and HPI increased as a result of SAT. The removal rates of fluorescent materials with three to five fused benzene rings and humic acid-like fluorescent materials with excitation wavelength/emission wavelength (λex/λem) of 390~ 410nm/456~476nm in each DOM fraction during SAT were lower than those of organics (on average) comprising dissolved organic carbon (DOC) in corresponding fraction. Other fluorescent materials in different fractions exhibited distinct removal behavior.
2010 Vol. 30 (10): 1353-1358 [Abstract] ( 219 ) [HTML 1KB] [ PDF 349KB] ( 677 )
1359 The release characteristics of phenol in sewage sludge and its risk assessment and control.
WENG Huan-Xin, CHU Bin, ZHANG Jin-Jun, MA Xue-Wen
The phenol contents in several types of sewage sludge were determined. The characteristics of phenol release under natural condition and at various temperatures, as well as factors that impact this process were assessed. The carcinogenic risks due to the phenol release were evaluated, based on which a number of potential control measures were proposed. Phenol content in the sewage sludge ranged from 0.17 to 3.22μg/g. The phenol release decreased as the aerial exposure of sewage sludge prolonged. When dried at low temperature, the released phenol was mainly derived from the phenol pre-dissolved in the sewage sludge. When dried at higher temperature, the primary phenol release was resulted from the pyrogenation of organic matters contained in the sewage sludge. The current sewage sludge drying protocol adopted by the Hangzhou municipal sewage management required a drying temperature at 350℃, which exerted high carcinogenic risks to workers with exposure potentials. By lowering the temperature of sewage sludge drying, it could effectively lower the health harm risks due to the phenol release in this process.
2010 Vol. 30 (10): 1359-1368 [Abstract] ( 169 ) [HTML 1KB] [ PDF 711KB] ( 539 )
1369 Stoichiometry characteristics of carbon, nitrogen, phosphorus and anaerobic carbon decomposition of wetland soil of different texture.
WANG Wei-Qi, TONG Chuan, ZENG Cong-Sheng
To clarify the stoichiometry characteristics of carbon, nitrogen, phosphorus and anaerobic carbon decomposition of wetland soil of different texture, the stoichiometry characteristics of carbon, nitrogen, phosphorus and anaerobic carbon decomposition of soil of two texture (loam and sandy soil) under Phragmites australis and Scirpus triqueter stands in Minjiang River estuary were analyzed. Loam carbon content was 14.61 mg/g, nitrogen was 1.01 mg/g and phosphorus was 0.64 mg/g,which were higer than that of sandy soil carbon(9.02 mg/g), nitrogen (0.16 mg/g) and phosphorus(0.42 mg/g).Averaged C/N ratios of loam was lower than sandy soil and C/P, N/P ratios were higer than sandy soil.The averaged methane production potential of 0~40 cm loam and sandy soil were 0.0072, 0.0019μg/(g·d) and carbon dioxide were 33.5134, 4.9239μg/(g·d), respectively.The potentials of two kinds of carbon decomposition production from loam were all higher than that of sandy soil. The stoichiometry characteristics of carbon, nitrogen, phosphorus had a preferable indication for anaerobic carbon decomposition.
2010 Vol. 30 (10): 1369-1374 [Abstract] ( 195 ) [HTML 1KB] [ PDF 461KB] ( 885 )
1375 Effects of soil nutrient and soil microbial biomass on soil enzyme activities in abandoned croplands with different restoration age.
WANG Bing, LIU Guo-Bin, XUE Sha
In order to make a better understanding on the effects of soil nutrient and soil microbial biomass on soil enzyme activities under erosion environment, long-term located farmland with an abandoned age sequences of 0, 1, 5, 7, 10, 15, 20, 25, 30, 40, and 50 years in Zhifanggou watershed (8.27km2 ), Shaanxi Province were studied, which was a typical erosion environment on loess hilly region. The coupling relationships among indexes of soil enzyme with soil nutrient and microbial biomass were analyzed by using stepwise and nonlinear regression. Soil enzyme activities had a significant correlation with soil fertilizer and soil microbial biomass except a-amylase (P<0.05). For soil enzyme activities and soil fertilizer factors, Urease (URE) and cellulase (CEL) were affected by total N, alkaline phosphatase (ALP) and catalase (CAT) were affected by available N, saccharase (SAC) and polyphenol oxidase (PPO) were affected by available N and organic matter. For soil enzyme activities and soil microbial biomass, Urease (URE) was affected by soil microbial biomass P; alkaline phosphatase (ALP), catalase (CAT), saccharase (SAC) and polyphenol oxidase (PPO) were affected by soil microbial biomass C, cellulase (CEL) was affected by soil microbial biomass N. However, polyphenol oxidase (PPO) decreased with the increase of available N, organic matter and soil microbial biomass C. There was a significant logarithmic relationship among those indexes (y=b+alnx, P<0.05).
2010 Vol. 30 (10): 1375-1382 [Abstract] ( 219 ) [HTML 1KB] [ PDF 648KB] ( 664 )
1383 Adsorption and desorption of three tetracycline antibiotics in cinnamon soils of China.
BAO Yan-Yu, ZHOU Qi-Xing, WAN Ying, YU Qiang, XIE Xiu-Jie
On the basis of the OECD Guideline 106, batch adsorption methods were employed to reveal the adsorption and desorption process of three tetracycline antibiotics in cinnamon soils. The Freundlich model was the best isotherm to describe all experimental datas of adsorption and desorption, and the average fitting correlation coefficient was 0.991. Among three antibiotics, chlortetracycline adsorption isotherms resembled S-type curves, oxytetracycline adsorption isotherms resembled the L-type curves, and tetracycline adsorption isotherms resembled the linear curves according to adsorption strength (1/n). For two soils, the adsorption capacity (lgKf) was in the order chlortetracycline (4.003 and 4.307) > tetracycline (3.198 and 3.252) > oxytetracycline (2.724 and 2.932). The dominant mechanism of three tetracycline antibiotics adsorption was physical adsorption in cinnamon soils. HI of oxytetracycline was significantly higher than that of tetracycline and chlortetracycline (P0.05) between tetracycline and chlortetracycline for HI.
2010 Vol. 30 (10): 1383-1388 [Abstract] ( 269 ) [HTML 1KB] [ PDF 364KB] ( 1217 )
1389 Adsorption of phenol on amphoteric-cationic modified lou soil
BAI Jun-Feng, MENG Zhao-Fu, LIU Yuan-Hui, QIN Pu-Xue, ZHENG Ping-Ying, XUN Lu-Lu, GUO Cai-Hong
Using batch experiment, the adsorption of phenol on clay layer (CL) of Lou soil modified with a mixture of amphoteric modifier, dodecyl dimethyl betaine (BS-12), and cationic modifier, cetyltrimethylammonium bromide (CTMAB), were carried out, and its adsorption mechanism was discussed also. The adsorption capacity of phenol on CL of Lou soil could be enhanced significantly by complex modification. The phenol adsorption was ordered by CK(Unmodified soil) <50BS(50%BS-12)<100BS(100%BS-12)<50BS+25CT(50%BS-12+25%CTMAB)<100BS+25CT (100%BS-12+25%CTMAB)<50BS+50CT(50%BS-12+50%CTMAB)<100BS+50CT(100%BS-12+50%CTMAB) at 20℃ and CK(Unmodified soil)<50BS(50%BS–12) <100BS(100%BS-12) <50BS+25CT(50%BS-12+25%CTMAB)< 50BS+50CT(50%BS-12+50%CTMAB)<100BS+25CT(100%BS-12+25%CTMAB)<100BS+50CT(100%BS-12+50%CTMAB) at 40℃. Henry equation was used to describe the phenol adsorption isotherm. The adsorption of phenol on the complex modified soil was a process with characteristics of both exothermic reaction and enthalpy decrease, its spontaneity being controlled by enthalpy decrease.
2010 Vol. 30 (10): 1389-1394 [Abstract] ( 239 ) [HTML 1KB] [ PDF 480KB] ( 704 )
1395 Construction of Rhodopseudomonas palustris phbC-hupL double mutant and determination of H2 production.
WANG Zhong-Kang, TIAN Yuan-Ming, LIAO Qiang, ZHANG Bao-Peng, YIN You-Ping
To improve the hydrogen produce ability of bacteria strain, a di-mutant bioengineering strain of Rhodopseudomonas palustris, with phbC (PHB synthase) and hupL (uptake hydrogenase) gene knocked-out, was constructed. The bacteria strains of R. palustris CQU01 isolated from silt for phbC gene knocked out, and R. palustris CQU012 with hupL knocked out which had been constructed before in our lab were used as the initial strains. The single mutant strain R. palustris CQU013 with phbC knocked out and double mutant strain R. palustris CQU014 with phbC-hupL knocked out were obtained by constructing a suicide vector containing erythromycin cassette used homologous double exchange and recombining into R. palustris CQU01 with conjugative transfer. The correct integration of the mutants was confirmed by PCR test and subsequent sequence analysis. The bacterial growth curves and hydrogen production characteristics of the mutant strains showed that the biological characters of the mutant strains had some differences with the wild strain R. palustris CQU01. The total H2 yield of R. palustris CQU013 and R. palustris CQU014 increased by 31% and 76% respectively comparing to wild strain, which up to 454mL and 604mL per liter fermentation broth in 216 hours. The hydrogen produce ability of di-mutant R. palustris CQU014 increased remarkably after the phbC gene and hupL gene be knocked out. This approved that both phbC gene and hupL gene in R. palustris affected the yield of hydrogen produce. The mutant strain R. palustris CQU014 may be a promising bacterial strain in hydrogen bio-produce.
2010 Vol. 30 (10): 1395-1401 [Abstract] ( 311 ) [HTML 1KB] [ PDF 489KB] ( 572 )
1402 Distribution of dissolved amino acids and its environmental significance in water of Taihu Lake, China.
YAO Xin, ZHU Guang-Wei, QIN Bo-Qiang
The concentrations and molecular weight of dissolved amino acids (DAAs) were investigated in water of Taihu, a large, shallow and eutrophic freshwater lake in China. DAAs were mainly existed as “true dissolved” form in the lake water, which colloidal form average occupied 10% of DAAs. Concentration of DAAs showed a significant spatial heterogeneity, which was lowest in river mouth and was highest in the mouth of Meiliang Bay, a hypereutrophic bay of Taihu and serious Microcystis algal bloom happened each summer. Generally, histidine, arginine, lysine, serine and tryptophan were the main forms of DAAs in the water of Taihu. Internal sources mainly from the decomposing of plankton should be the main source of DAAs in Taihu. The composition of DAAs was also possible used as an indicator of biological degradation state of the organic matter in the lake.
2010 Vol. 30 (10): 1402-1407 [Abstract] ( 234 ) [HTML 1KB] [ PDF 422KB] ( 866 )
1408 Dynamics of biomass and N, P storage of Phragmites australis in Hangzhou Bay Wetlands
WU Tong-Gui, WU Ming, YU Mu-Kui, XIAO Jiang-Hua
Seasonal dynamics of leaf and stem biomass, as well as N, P content and N, P storage were determined in Global Environment Fund (GEF) program site, Hangzhou Bay Wetlands. With the growth of Phragmites australis, leaf and aboveground biomass increased firstly and reached the maximum value in September, then decreased. While stem biomass increased during the whole growth season. It showed higher N, P concentrations at the early stage (April~May) because of small biomass, then decreased greatly with the expanding of leaf when going into fast growing period (June~July), and increased as the leaf growth became stable (August~September), finally, decreased again with the leaf becoming senescence. But N, P content of the stem decreased gradually in whole growth period. There was a good relationship between N, P storage and biomass, and highest storage was found for leaf in August with (10.28±3.88) and (0.53±0.21)g/m2, and for stem and aboveground biomass in September, the values were (7.33±2.22), (0.57±0.04) and (16.48±1.07), (1.01±0.10)g/m2, respectively.
2010 Vol. 30 (10): 1408-1412 [Abstract] ( 240 ) [HTML 1KB] [ PDF 458KB] ( 915 )
1413 Characteristic of daily total exposure to polycyclic aromatic hydrocarbons of people living in coal-fired area in Qujing, Yunnan Province
ZHANG Lin-Lin, 吕Jun-Gang , WU Guo-Ping, WEI Fu-Sheng
To assess polycyclic aromatic hydrocarbons(PAHs) exposure, subjects were selected in the area where local residents burn smoky coals in Qujing, Yunnan province. 16 PAHs concentrations of the samples were determined by GC/MS to study status, characteristic and sources of the PAHs. Daily total exposure of local people was analyzed using benzo(a)pyrene (BaP) toxic equivalence factor. Daily intake through food was 0.20μg/d, which was in the range of the data reported by WHO. Daily intake through air was 5.26μg/d, which contributed 96% of the their daily PAHs exposure. Inhalation was the main intake of PAHs. The proportion of the high molecular weight PAHs increased from 3.08% to 49.6% using toxic equivalence factor to assess the carcinogenic risk, while low molecular weight PAHs exhibited much lower toxicity decreased. The daily total exposure to BaP was 5.46μg/d, which was exceeded the limited value 3μg/d. PAHs exposure posed long-term threat to the environment and health of residents.
2010 Vol. 30 (10): 1413-1418 [Abstract] ( 213 ) [HTML 1KB] [ PDF 380KB] ( 709 )
1419 Interaction between chlorophenols and acetycholinesterase determined by spectroscopic methods
LIU Qiong-Yu, ZHOU Pei-Jiang, CHEN Yan
The interaction of acetycholinesterase (AChE) with 2,4,6-trichlorophenol (2,4,6-TCP) and pentachlorophenol (PCP) was studied by fluorescence and UV-Vis spectroscopy. The Stern-Volmer quenching constants, binding constants, thermodynamic parameters and binding distance were obtained. The intrinsic fluorescences of AChE were quenched regularly by 2,4,6-TCP and PCP, respectively. Static quenching mechanism played the major roles when the temperature was less than 303K. The thermodynamic parameters indicated that the binding reaction was spontaneous and being driven by entropy, and the hydrophobic force played the major roles in the binding of AChE and chlorophenols. The binding distance r between AChE and chlorophenols was 1.91 nm for 2,4,6-TCP and 2.00 nm for PCP, respectively. The binding constants of AChE with 2,4,6-TCP and PCP were in the range of 104~105L/mol. Energy transfer from AChE to 2,4,6-TCP and PCP occurred, and the AChE-chlorophenols complex was formed. The binding reaction between 2,4,6-TCP and AChE was stronger than those between PCP and AChE, which was attributed to the competition between hydrophobic effect and stereo-hindrance effect.
2010 Vol. 30 (10): 1419-1424 [Abstract] ( 235 ) [HTML 1KB] [ PDF 449KB] ( 827 )
1425 Potential of bio-energy substitute fossil energy and environmental effects
CHEN Ya-Lin, GAO Ji-Xi, LI Yong-Hong
Emergy wastage of fossil energy and the emergy that agricultural residues can substitute were calculated based on the statistical data during 1953 to 2007. The emergy of agricultural residues could almost compensate for that of fossil energy consumption in the early China. However, the disparity of emergy between wastage of fossil energy and agricultural residues supply was getting huger along with the society and economic development. The emergy that supplied by agricultural residues only accounted for 10.35% of which that the fossil energy consumption in 2007. It could reduce much environmental value loss if fossil energy were substituted by bio-energy. The reduced environmental governance cost was 773.91×108 yuan because of reducing coal mining and the environmental value loss because of fossil energy consumption was 11311.76×108 yuan from 1990 to 2007. Among them, the environmental value loss because of reducing sulfur dioxide emission was the most, which accounted for 56.93%. The environmental value loss because of reducing nitrogen oxides and ash emission respectively accounted for 33.13% and 9.94%.
2010 Vol. 30 (10): 1425-1431 [Abstract] ( 177 ) [HTML 1KB] [ PDF 451KB] ( 732 )
1432 Energy efficiency, potential of CO2 emission reduction and its determinants across Chinese regions.
ZENG Xian-Gang
Based on the DEA approach, this paper estimates a comprehensive energy efficiency indicator which incorporates CO2 emission for 30 provinces/cities in China using the panel data from 2000 to 2007, and then investigates its determinants by employing a Tobit model. The estimation results show that the four provinces with the highest energy efficiency in China are Shanghai, Guangdong, Hainan and Qinghai, which is different from the energy efficiency estimation that does not take into account CO2 emissions. The reduction potential of CO2 emission in these provinces shows five kinds of trends, including the basically unchanged, up after going down, down after going up, steadily rising, and steadily declining. The provinces which have high potential for emission reduction are Shandong, Shanxi, Hebei and Liaoning. The government’s expenditure and the opening degree have a significant influence on energy efficiency, while the industry structure and enforcement of environmental protection aren’t closely related with it.The impact of technology progress cannot be clearly identified for lacking of appropriate measurement.
2010 Vol. 30 (10): 1432-1440 [Abstract] ( 236 ) [HTML 1KB] [ PDF 509KB] ( 964 )
中国环境科学
  News
More>>  
  下载中心
   Instruction
   Template
   Copyright Agreement
More>>  
  Links
   Ministry of Land and
　  Resources of the People,s
　  Republic of China
    CNKI
    WANFANG DATA
    CNPITC
More>>  
 
CHINA ENVIRONMENTAL SCIENCECE
Links： China Association for Science and Technology　Chinese Society For Environmental Sciences　CNKI　WANGFANG DATA
Copyright © 2010 Editorial By China Environmental Science　　Support by Beijing Magtech Co.ltd, E-mail:support@magtech.com.cn