-
[show abstract]
[hide abstract]
ABSTRACT: Support vector regression (SVR) method is a novel type of learning machine algorithms, which is seldom applied to the development
of urban atmospheric quality models under multiple socio-economic factors. This study presents four SVR models by selecting
linear, radial basis, spline, and polynomial functions as kernels, respectively for the prediction of urban dust fall levels.
The inputs of the models are identified as industrial coal consumption, population density, traffic flow coefficient, and
shopping density coefficient. The training and testing results show that the SVR model with radial basis kernel performs better
than the other three both in the training and testing processes. In addition, a number of scenario analyses reveal that the
most suitable parameters (insensitive loss function ɛ, the parameter to reduce the influence of error C, and discrete level or average distribution of parameters σ) are 0.001, 0.5, and 2 000, respectively.
Key wordssupport vector regression-urban air quality-dust fall-socio-economic factors-radial basis function
Journal of Central South University of Technology 04/2012; 17(2):307-315. · 0.36 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The effects of dry deposition, canopy leaching, precipitation ion concentration, and precipitation H+ concentration on net throughfall flux (NTF, throughfall minus bulk precipitation) were evaluated on a seasonal basis by using
a multiple regression analysis approach based on an observation period of 4 years in Shaoshan subtropical mixed evergreen
forest, south-central China. Regression analysis results indicated that the estimated canopy exchange flux was the dominant
factor regulating the NTF and the calculated dry deposition was a minor term. The seasonal dry deposition of base cations
accounted for 15%–43% of the NTF. The NTF analysis showed that K+, Ca2+, Mg2+, Na+, and weak acids in throughfall were derived from foliar leaching and the canopy uptakes of H+, NH4
+, and NO3
− were from precipitation. The retention rate of proton (H+ and NH4
+) in the canopy was close to the canopy leaching rate of base cations when corrected for weak acids because weak acid-induced
canopy leaching did not exchange with protons, which suggested that the canopy leaching processes neutralized acid precipitation
in Shaoshan forest.
Journal of Forest Research 04/2012; 11(6):389-396. · 0.77 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The laccase activities of Penicillium simplicissimum H5 during solid-state fermentation with rice straw were studied. Degradation of lignocellulose was also followed. Results
showed that all supplemental carbon sources inhibited the laccase activity in different degrees, while suitable concentrations
of supplemental nitrogen sources remarkably enhanced the laccase activity. The enhancement of activity by the ordinary laccase
inducers 2, 2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) and xylidine was not observed in this study. Lignocellulose
degradation was improved when laccase activity was relatively low, suggesting a polymerizing function of laccase in lignin
degradation by P. simplicissimum.
World Journal of Microbiology and Biotechnology 04/2012; 22(4):317-324. · 1.53 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To reduce and eliminate the hazards of pentachlorophenol (PCP) to the soil, the method of inoculating free and immobilized white rot fungi, Phanerochaete chrysosporium to PCP-polluted soils was investigated. Three parallel beakers A, B, C are adopted with the same components of soil, yard waste, straw and bran for aerated composting to degrade the PCP in soil. A was with no inoculants as control, B was added with the inoculants of immobilized P.␣chrysosporium, C was inoculated with non-immobilized P. chrysosporium, and additionally D contained only PCP-contaminated soils also as control. By contrastive analyses, the feasibility of applying composting to the bioremediation of the PCP-polluted soil was discussed. From the experimental results, it could be seen that the degradation rate of PCP by the immobilized fungi exceeded 50% at day 9, while that of the non-immobilized fungi achieved the same rate at day 16. However, the final degradation rates of PCP for both of them were beyond 90% at day 60 and that the rate of A was much lower than the others. The above data have shown that the degradation effect of inoculating P. chrysosporium was better than that of no inoculation, and that of the immobilized fungi was better than that of non-immobilized ones. Meanwhile, shown by all the indicators the composts of A, B and C were mature and stabilized at the end of the experiment. Therefore, the method of composting with immobilized P.␣chrysosporium is effective for the bioremediation of PCP-contaminated soil.
World Journal of Microbiology and Biotechnology 04/2012; 22(9):909-913. · 1.53 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: This work developed a relatively inexpensive and layers-film construction electrochemical sensor for DNA recognition and its performance was investigated. The Fe(3)O(4) magnetic nanoparticles-cysteine were immobilized on the carbon paste electrode (CPE) surface using magnetic force. Multiwalled carbon nanotubes (MWCNTs), gold nanoparticles (GNPs), and chitosan (Chi) were used successively to coat on the electrode surface. The thiolated capture probe was assembled and competitively hybridized with the target nucleic acid and biotinylated response probe. The electrochemical behavior was analyzed by cyclic voltammetry and electrochemical impedance spectroscopy. In addition, the sensor performance was also analyzed by introducing the notion of detection efficiency. The experimental results showed that although the electron transfer capability of the CPE is less strong than that of a metal electrode used in the DNA sensor, the materials modified on the CPE could significantly improve the performance. A detection limit of 1 nM of target DNA and a sensitivity of 2.707 × 10(3) mA M(-1) cm(-2) were obtained. Although the resulting detection limit was not remarkable, further experiments could improve it.
The Analyst 08/2011; 136(20):4204-10. · 4.23 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Picloram is a widely used chlorinated herbicide, which is quite persistent and mobile in soil and water with adverse health and environmental risks. A simple and efficient method with high sensitivity and good selectivity was developed in this work to analyze picloram. The aldehyde group functionalized quartz glass plate was used to catch picloram by Schiff base reaction, and reacted with the liposomes-labeled antibody. The fluorescein isothiocyanate (FITC) solution was encapsulated in the liposomes. After being released from the liposomes, the fluorescence of FITC was measured by a fluorimeter. It was found that the fluorescence intensity is linearly correlated to the logarithm of picloram concentration, ranging from 1.0 × 10(-4) to 100 ng mL(-1), with a detection limit of 1.0 × 10(-5) ng mL(-1). Picloram concentration in real wastewater samples were accurately measured by the proposed method and HPLC, the results of the two methods were approximately the same. The proposed method showed high sensitivity and good selectivity, and could be an efficient tool for picloram quantitative analysis.
Talanta 11/2010; 83(1):210-5. · 3.79 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: This paper proposed an inexact reverse logistics model for municipal solid waste management systems (IRWM). Waste managers, suppliers, industries and distributors were involved in strategic planning and operational execution through reverse logistics management. All the parameters were assumed to be intervals to quantify the uncertainties in the optimization process and solutions in IRWM. To solve this model, a piecewise interval programming was developed to deal with Min-Min functions in both objectives and constraints. The application of the model was illustrated through a classical municipal solid waste management case. With different cost parameters for landfill and the WTE, two scenarios were analyzed. The IRWM could reflect the dynamic and uncertain characteristics of MSW management systems, and could facilitate the generation of desired management plans. The model could be further advanced through incorporating methods of stochastic or fuzzy parameters into its framework. Design of multi-waste, multi-echelon, multi-uncertainty reverse logistics model for waste management network would also be preferred.
Journal of Environmental Management 10/2010; 92(3):522-30. · 3.24 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: An interval-parameter two-stage chance-constraint mixed integer linear programming (ITCMILP) model is provided for supporting long-term planning of solid waste management in the City of Foshan, China. The ITCMILP is formulated by integrating interval-parameter, two-stage, mixed integer, and chance-constraint programming methods into a general framework, and can thus deal with multiple uncertainties associated with model parameters, constraints and objectives. Three scenarios are examined, covering combinations of various system conditions and waste management policies. Scenario 1 is designed for comparison purposes. Scenarios 2 and 3 correspond to situations when the existing landfill's life is to be extended. The results demonstrate that the centralized composting and incinerating facilities are desired for treating the organic waste flows. The tradeoff among system cost, violation risk, and the related policy implications are also analyzed. The results obtained could help decision makers gain in-depth insights into the impact of uncertainties on long-term solid waste management in the City of Foshan.
Journal of Environmental Management 10/2009; 91(2):389-402. · 3.24 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Elevated concentrations of arsenic were detected in surface soils adjacent to a smelting complex in northern Canada. We evaluated the cancer risks caused by exposure to arsenic in two communities through combining geostatistical simulation with demographic data and dose-response models in a framework. Distribution of arsenic was first estimated using geostatistical circulant-embedding simulation method. We then evaluated the exposures from inadvertent ingestion, inhalation and dermal contact. Risks of skin cancer and three internal cancers were estimated at both grid scale and census-unit scale using parametric dose-response models. Results indicated that local residents could face non-negligible cancer risks (skin cancer and liver cancer mainly). Uncertainties of risk estimates were discussed from the aspects of arsenic concentrations, exposed population and dose-response model. Reducing uncertainties would require additional soil sampling, epidemic records as well as complementary studies on land use, demographic variation, outdoor activities and bioavailability of arsenic.
Environmental pollution (Barking, Essex: 1987) 05/2009; 157(8-9):2413-20. · 3.43 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Previously, adsorption feature of a dirhamnolipid biosurfactant on diverse microbial cells was studied and the effect of the adsorption on cell surface hydrophobicity was compared. In this paper, the adsorption behavior of a monorhamnolipid and a dirhamnolipid on cells of two Pseudomonas aeruginosa strains was investigated in order to further reveal the influence of biosurfactant structure and cell property on the adsorption and the relation between the adsorption and cell surface hydrophobicity. Experimental results showed that the adsorption capacity of all the cells to monorhamnolipid was much stronger than to dirhamnolipid, and the rhamnolipid-sourced P. aeruginosa cells, no matter grown on glucose or hexadecane, released extra dirhamnolipid when aqueous concentration of dirhamnolipid was too high. Length of surfactant alkyl chain as well as the type of carbon source used to cultivate the cell adsorbents had only minor influence on the adsorption. The adsorption was assumed to be driven by polar interaction between the rhamnolipid molecules and the cell surface chemical groups. The directional orientation of the rhamnolipid molecules with hydrophobic moiety extending to the environment may account for the rapid increase of cell surface hydrophobicity at low aqueous concentrations of the surfactant, while the stable or decreased cell hydrophobicity was probably the consequence of multiple surfactant layer formation or hemimicelle accumulation.
Applied Microbiology and Biotechnology 07/2008; 79(4):671-7. · 3.42 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: This study advances an integrated simulation, inference, and optimization method (ISIOM) for optimizing groundwater remediation systems. SIOM has the advantages of (i) automotive screening of potential explanatory variables (e.g., the pumping rates at various remediation wells), (ii) providing a flexible manner for investigating the linear, interactive, and quadratic effects of operating conditions on the benzene levels, and (iii) mitigating the computational efforts in optimization processes. The method is applied to a petroleum-contaminated site in western Canada for identifying the optimal remediation strategies under a given set of remediation durations and environmental standard levels. To examine the effect of pumping duration on contaminants removing efficiency, 4 duration options are considered including 5, 10, 15, and 20 years, respectively. The results indicate that the pumping duration would have effect on the optimized scheme. It is suggested that the 10-year duration would be more desirable than the 15-year one. The simulation results demonstrate that the peak benzene concentrations would be reduced to satisfy the environmental standard when the optimal remediation strategy is carried out.
Water Research 06/2008; 42(10-11):2629-39. · 4.86 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The previous inexact mixed-integer linear programming (IMILP) method can only tackle problems with coefficients of the objective function and constraints being crisp intervals, while the existing inexact mixed-integer semi-infinite programming (IMISIP) method can only deal with single-objective programming problems as it merely allows the number of constraints to be infinite. This study proposes, an inexact mixed-integer bi-infinite programming (IMIBIP) method by incorporating the concept of functional intervals into the programming framework. Different from the existing methods, the IMIBIP can tackle the inexact programming problems that contain both infinite objectives and constraints. The developed method is applied to capacity planning of waste management systems under a variety of uncertainties. Four scenarios are considered for comparing the solutions of IMIBIP with those of IMILP. The results indicate that reasonable solutions can be generated by the IMIBIP method. Compared with IMILP, the system cost from IMIBIP would be relatively high since the fluctuating market factors are considered; however, the IMILP solutions are associated with a raised system reliability level and a reduced constraint violation risk level.
Waste Management 05/2008; 29(1):21-31. · 2.43 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: This study develops a nonlinear chance-constrained programming (NCCP) model for optimizing surfactant-enhanced aquifer remediation (SEAR) processes. The model can not only address the parameter uncertainty, but provide a reliability level for the identified optimal remediation strategy. To solve the NCCP model, stepwise cluster analysis (SCA) is used to create a set of proxy simulators for quantifying the relationships between operating conditions (i.e., pumping rate) and probabilities of benzene levels in violation of standard. Compared to conventional parametric inference techniques, SCA is independent of prior assumptions for model forms (e.g., linear or exponential ones) and capable of reflecting complex nonlinear relationships between operating conditions and probabilities. To alleviate the computational efforts in the optimization process, the generated proxy simulators are repeatedly called by simulated annealing (SA) to test the feasibility of each potential solution. The implicit of the optimal NCCP solutions is discussed through a laboratory-scale SEAR system where porosity and intrinsic permeability are treated as stochastic parameters. It is observed that well locations, environmental standards, reliability levels and remediation durations would have significant effects on optimal SEAR strategies. By comparing the predicted benzene concentration without and with remediation actions, it is indicated that the optimal SEAR process can guarantee the benzene concentration to meet the environmental standard with a high reliability level.
Environmental Science and Technology 04/2008; 42(6):2009-14. · 5.23 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In this study, adsorption of dirhamnolipid biosurfactant on a Gram-negative Pseudomonas aeruginosa, two Gram-positive Bacillus subtilis, and a yeast, Candida lipolytica, was investigated, and the causality between the adsorption and change of cell surface hydrophobicity was discussed. The adsorption was not only specific to the microorganisms but also depended on the physiological status of the cells. Components of the biosurfactant with different rhamnosyl number or aliphatic chain length also exhibited slight difference in adsorption manner. The adsorption indeed caused the cell surface hydrophobicity to change regularly; however, the changes depended on both the concentrations of rhamnolipid solutions applied and the adsorbent physiological conditions. Orientation of rhamnolipid monomers on cell surface and micelle deposition are supposed to be the basic means of adsorption to change cell hydrophobicity at low and high rhamnolipid concentrations, respectively. This study proposed the possibility to modify cell surface hydrophobicity with biosurfactant of low concentrations, which may be of importance in in situ soil remediation.
Applied Microbiology and Biotechnology 12/2007; 77(2):447-55. · 3.42 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Three kinds of adsorbents-potassium dihydrogen phosphate, sawdust and mixture of potassium dihydrogen phosphate and sawdust were added respectively into composting to investigate their adsorption effect on ammonia. The experimental results showed that all the adsorbents could restrain ammonia volatilizing, with the sorption of potassium dihydrogen phosphate adsorbents being the best of all, the sorption of mixture adsorbent with potassium dihydrogen phosphate and sawdust being the second and the sorption of sawdust adsorbent being the last. Therefore, the total nitrogen loss ratios respectively reduced from 38% to 13%, 15% and 21% after adding these three kinds of adsorbents into composting. However, potassium dihydrogen phosphate produced negative influence on composting properties as its supplemented amount exceeded a quantity basis equivalent to 18% of total nitrogen in the composting, for example: pH value had been lessened, microorganism activity reduced, which finally resulted in the reduction of biodegradation ratio of organic matter. But it did not result in these problems when using the mixture of potassium dihydrogen phosphate and sawdust as adsorbent, in which the amount of potassium dihydrogen phosphate was under a quantity basis equivalent to 6% of total nitrogen in the composting. Moreover, the mixture adsorbent produced better adsorption effect on ammonia, and raised biodegradation ratio of organic matter from 26% to 33%.
Journal of Hazardous Materials 04/2007; 141(3):736-44. · 4.17 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Bacterial communities were analyzed using Biolog method in agricultural waste composting. The results of cluster analysis and principle component analysis indicated that bacterial communities varied greatly during the first stage of composting, while began to stabilize during the second stage. Bacteria that could utilize the first and second kinds of carbon sources on Biolog plate were found to be the dominant ones during composting, which were also believed to be related with lignocellulose degradation. Thermophilic bacteria were believed to be able to metabolize the fourth and sixth kinds of carbon sources on Biolog plate. Thereinto, the fourth kinds of carbon sources were also connected with lignocellulose transformation. The bacteria utilizing the sixth kinds of carbon sources were just able to metabolize some simpler organic matters.
ACTA MICROBIOLOGICA SINICA 03/2007; 47(1):98-102.
-
[show abstract]
[hide abstract]
ABSTRACT: In the experiment four parallel beakers A, B, C,D were adopted, among which A was without any inoculum, B was added with the inocula of immobilized Phanerochaete chrysosporium, C was inoculated with non-immobilized Phanerochaete chrysosporium, and D was only with pentachlorophenol (PCP)-contaminated soils open to air. By contrastive analyses, the feasibility of applying composting to the bioremediation of the PCP-contaminated soil was discussed. It can be seen from the experimental results that composting with inocula was better than that without innoculation and after 60d composting, more than 94% PCP in the compost was degraded; meanwhile the effect by immobilized fungi was better than that by nonimmobilized one. From the experimental data it shows that the PCP degradation achieved 50% on 9d by immobilized fungi. What's more, shown by indicators of germination index, volatile solids, microbial carbon activity and other factors, the compost were mature and of no hazard to plant at the end, which provided the benign environment for the Phanerochaete chrysosporium to degrade the PCP so that the bioremediation and composting could be combined together.
Huan jing ke xue= Huanjing kexue / [bian ji, Zhongguo ke xue yuan huan jing ke xue wei yuan hui "Huan jing ke xue" bian ji wei yuan hui.] 01/2007; 27(12):2553-7.
-
[show abstract]
[hide abstract]
ABSTRACT: The activities of lignin-degrading peroxidases are the primary decomposition indexes in compost bioremediation. In this paper, artificial neural networks (ANNs) have been combined with an enzyme sensor for simultaneous determination of lignin peroxidase (LiP) and manganese peroxidase (MnP) activities secreted by Phanerochaete chrysosporium in composting of municipal solid waste. The LiP and MnP activities were detected through catalytic redox of H2O2, hydroquinone and veratryl alcohol as substrates by an amperometric sensor immersed in the culture filtrate solution. Due to the dynamic, nonlinear and uncertain characteristics of the complex composting system, ANNs have been used as a chemometric tool for overlapping signal deconvolution and modelling to quantify the two enzyme activities separately. Feedforward backpropagation network was used for the training process. The effects of the transfer functions, the amount of current values, the number of hidden neurons and the optimization algorithm were investigated. The LiP activities in the filtrate varied from 8.14 to 29.79 U L(-1), and from 0.36 to 1.37 U L(-1) for MnP activities. A good prediction capability was obtained, with correlation coefficients of 0.9936 for LiP activity and 0.9976 for MnP activity between the expected and predicted values of the external test samples. The performance of the ANN model was compared with the linear regression model in respect to simulation accuracy, adaptability to uncertainty, etc. All the results show that the combination of amperometric enzyme sensor and artificial neural networks is a rapid, sensitive and robust method in the quantitative study of composting system.
Analytica chimica acta 11/2006; 579(1):109-16. · 4.31 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The agricultural by-product of Lentinus edodes was used as a novel biosorbent for bioremediation of chromate contaminated waste water in the simulated experimental conditions. The contact time, particle size, biosorbent dosage and optimum pH range were investigated to optimize the sorption condition. The biosorption by the biomass was strongly affected by pH. At pH 1.0-2.5, all hexavalent chromium was diminished, either removed by the biosorbent or reduced to less toxic trivalent chromium even in very high concentration of 1000 mg/L. The adsorbed hexavalent chromium and reduced trivalent chromium were both linearly dependent on the initial chromium concentration. Most uptake of Cr occurred at pH around 4. The maximum uptake of chromium was 21.5 mg/g when simulated with Langmuir model, which showed the potential biosorption capacity of this biomaterial. The change of oxidation-reduction potential (ORP) during biosorption process revealed strong reduction ability of this biosorbent. Comparing analysis from Fourier transform infrared spectrums indicated that nitrogen oxide and carboxyl groups were increased after biosorption. The energy-dispersive X-ray microanalyzer revealed the mechanism of cation exchange during biosorption.
Journal of Hazardous Materials 08/2006; 135(1-3):249-55. · 4.17 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The bioremediation of the simulated lead (Pb)-contaminated soils by incubating with Phanerochaete chrysosporium and straw was studied at laboratory-scale. The soil pH, Pb concentration, soil microbial biomass, microbial metabolic quotient, microbial quotient and microbial biomass C-to-N ratios were monitored. The above indicators were to study the stress of Pb on soil and the microbial effects during the bioremediation process. It was found that the soils treated with P. chrysosporium and straw showed a much lower concentration of soluble-exchangeable Pb, lower metabolic quotient and biomass C-to-N ratios (0mgkg(-1) dry weight soil, 1.9mg CO(2)-Cmg(-1) biomass carbon and 4.9 on day 60, respectively) and higher microbial biomass and microbial quotient (2258mgkg(-1) dry weight soil and 7.86% on day 60, respectively) compared with the controls. In addition, the kinetic parameters in the model based on logistic equation were calculated by the BIOLOG data. By analyzing those kinetic parameters some information on the metabolic capacity of the microbial community could be obtained. All the results indicated that the bioavailability of Pb in contaminated soil was reduced so that the potential stress of Pb was alleviated, and also showed that the soil microbial effects and the metabolic capacity of microbial community were improved.
Journal of Hazardous Materials 07/2006; 134(1-3):268-76. · 4.17 Impact Factor
