Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Chunjiang An is active.

Publication


Featured researches published by Chunjiang An.


Water Research | 2011

Effect of short-chain organic acids on the enhanced desorption of phenanthrene by rhamnolipid biosurfactant in soil-water environment.

Chunjiang An; Guohe Huang; Jia Wei; Hui Yu

This study investigated the effect of short-chain organic acids on biosurfactant-enhanced mobilization of phenanthrene in soil-water system. The desorption characteristics of phenanthrene by soils were assessed in the presence of rhamnolipid and four SCOAs, including acetic acid, oxalic acid, tartaric acid and citric acid. The tests with rhamnolipid and different organic acids could attain the higher desorption of phenanthrene compared to those with only rhamnolipid. Among the different combinations, the series with rhamnolipid and citric acid exhibited more significant effect on the desorption performance. The removal of phenanthrene using rhamnolipid and SCOAs gradually increased as the SCOA concentration increased up to a concentration of 300 mmol/L. The effects of pH, soil dissolved organic matter and ionic strength were further evaluated in the presence of both biosurfactant and SCOAs. The results showed that the extent of phenanthrene desorption was more significant at pH 6 and 9. Desorption of phenanthrene was relatively lower in the DOM-removed soils with the addition of biosurfactant and SCOAs. The presence of more salt ions made phenanthrene more persistent on the solid phase and adversely affected its desorption from contaminated soil. The results from this study may have important implications for soil washing technologies used to treat PAH-contaminated soil and groundwater.


Journal of Hazardous Materials | 2011

Combined effects of DOM extracted from site soil/compost and biosurfactant on the sorption and desorption of PAHs in a soil-water system.

Hui Yu; Guohe Huang; Chunjiang An; Jia Wei

The combined effects of DOM and biosurfactant on the sorption/desorption behavior of phenanthrene (PHE) and pyrene (PYR) in soil water systems were systematically investigated. Two origins of DOMs (extracted from soil and extracted from food waste compost) and an anionic biosurfactant (rhamnolipid) were introduced. The presence of DOM in the aqueous phase could decrease the sorption of PAHs, thus influence their mobility. Desorption enhancement for both PHE and PYR in the system with compost DOM was greater than that in the soil DOM system. This is due to the differences in specific molecular structures and functional groups of two DOMs. With the co-existence of biosurfactant and DOM, partitioning is the predominant process and the desorption extent was much higher than the system with DOM or biosurfactant individually. For PHE, the desorption enhancement of combined DOM and biosurfactant was larger than the sum of DOM or biosurfactant; however desorption enhancement for PYR in the combined system was less than the additive enhancement in two individual system under low PAH concentration. This could be explained as the competition sorption among PAHs, DOM and biosurfactant. The results of this study will help to clarify the transport of petroleum pollutants in the remediation of HOCs-contaminated soils.


Chemosphere | 2010

Effect of short-chain organic acids and pH on the behaviors of pyrene in soil-water system.

Chunjiang An; Guohe Huang; Hui Yu; Jia Wei; Wei Chen; Gongchen Li

The effects of five short-chain organic acids (SCOAs) on the behaviors of pyrene in soil-water system were investigated. The influences of the quantity and species of organic acids, pH, and soil dissolved organic matter were considered. The results showed the presence of SCOAs inhibited the adsorption and promoted the desorption of pyrene in the following order: citric acid>oxalic acid>tartaric acid>lactic acid>acetic acid. The decreased extents of pyrene adsorption performance enhanced with increasing SCOA concentrations, while the decreasing rate became less pronounced at high SCOA concentrations. In the presence of organic acids, the adsorption ability of pyrene decreased with increasing pH. However, there was a slight increase of pyrene adsorption with the addition of oxalic acid, tartaric acid and citric acid above pH 8. The capacity for pyrene retention differentiated significantly between the soils with and without dissolved organic matter. The presence of SCOAs was also favorable for the decrease of pyrene adsorption on soil without dissolved organic matter. The results of this study have important implications for the remediation of persistent organic pollutants in soil and groundwater.


Journal of Hazardous Materials | 2012

Performance of in-vessel composting of food waste in the presence of coal ash and uric acid.

Chunjiang An; Guohe Huang; Yao Yao; Wei Sun; Kai An

Massive quantities of food waste often coexist with other agroindustrial and industrial waste, which might contain coal ash (CA) and uric acid (UA). This study investigated the influence of CA and UA on the composting of food waste in the in-vessel system. The patterns of food waste composting were compared among various combinations. The results showed that the temperature level was enhanced in the presence of CA and UA during the first 8 days. The significant drop in pH was observed in the treatment without any amendment. But the presence of CA could alleviate the drop of pH. More intensive organic mass reduction took place in the treatments with amended CA and UA in the first half of process. The O(2) uptake rate in the reactor with CA and UA was higher than that with only CA in the early stage. Both thermophilic and mesophilic microorganisms were present throughout the composting period. The populations of both thermophilic and mesophilic microorganisms were influenced when amended with CA and UA. The decreasing trend in C/N ratio was shown in all the reactors, while a relatively lower C/N ratio was obtained in the series with both CA and UA.


Science of The Total Environment | 2017

Emerging usage of electrocoagulation technology for oil removal from wastewater: A review

Chunjiang An; Gordon Huang; Yao Yao; Shan Zhao

Electrocoagulation is a simple and efficient treatment method involving the electrodissolution of sacrificial anodes and formation of hydroxo-metal products as coagulants, while the simultaneous production of hydrogen at the cathode facilitates the pollutant removal by flotation. Oil is one of the most important hydrocarbon products in the modern world. It can cause environmental pollution during various stages of production, transportation, refining and use. Electrocoagulation treatment is particularly effective for destabilization of oil-in-water emulsions by neutralizing charges and bonding oil pollutants to generated flocs and hydrogen bubbles. The development of electrocoagulation technologies provided a promising alternative for oil removal from wastewater. This paper presents a review of emerging electrochemical technologies used for treating oil-containing wastewater. It includes a brief description of the oily wastewater origin and characteristics. The treatment processes developed so far for oily wastewater and the electrocoagulation mechanisms are also introduced. This paper summarizes the current applications of electrocoagulation for oil removal from wastewater. The factors that influence the electrocoagulation treatment efficiencies as well as the process optimization and modeling studies are discussed. The state-of-the-art and development trends of electrocoagulation process for oil removal are further introduced.


Environmental Science & Technology | 2012

Stepwise Adsorption of Phenanthrene at the Fly Ash–Water Interface as Affected by Solution Chemistry: Experimental and Modeling Studies

Chunjiang An; Guohe Huang

Fly ash (FA) is predominantly generated from coal-fired power plants. Contamination during disposal of FA can cause significant environmental problems. Knowledge about the interaction of FA and hydrophobic organic pollutants in the environment is very limited. This study investigated the adsorption of phenanthrene at the interface of FA and water. The performance of phenanthrene adsorption on FA and the effects of various aqueous chemistry conditions were evaluated. The adsorption isotherms exhibited an increasing trend in the adsorbed amounts of phenanthrene, while a stepwise pattern was apparent. A stepwise multisite Langmuir model was developed to simulate the stepwise adsorption process. The adsorption of phenanthrene onto FA was noted to be spontaneous at all temperatures. The thermodynamic results indicated that the adsorption was an exothermic process. The adsorption capacity gradually decreased as pH increased from 4 to 8; however, this trend became less significant when pH was changed from 8 to 10. The binding affinity of phenanthrene to FA increased after the addition of humic acid (HA). The pH variation was also responsible for the changes of phenanthrene adsorption on FA in the presence of HA. High ionic strength corresponded to low mobility of phenanthrene in the FA-water system. Results of this study can help reveal the migration patterns of organic contaminants in the FA-water system and facilitate environmental risk assessment at FA disposal sites.


Journal of Hazardous Materials | 2011

Investigation on the solubilization of polycyclic aromatic hydrocarbons in the presence of single and mixed Gemini surfactants

Jia Wei; Guohe Huang; Chunjiang An; Hui Yu

Water solubility enhancements of naphthalene (Naph), phenanthrene (Phen) and pyrene (Py) by a series of single cationic Gemini surfactants (CG(s), s=4, 8, 12 and 16) as well as their equimolar binary combinations (CG(12-m), m=4, 8 and 16) have been investigated. The relationships between their surface properties and solubilizing capacities toward three polycyclic aromatic hydrocarbons (PAHs) have been quantified and discussed. The selected single Gemini surfactants observably enhance the water solubility of PAHs following the order of Phen>Py>Naph except for CG(8) which has a superior solubilizing ability for Py. For the same organic compound, the solubilizing abilities of single Gemini surfactants are in tune with the order of variation tendencies of CMC values. However, the different mixed Gemini surfactant systems have shown selective solubilization on various PAHs which is not simply related to their mixed molar properties. Particularly, the CG(12-16) surfactant has relatively comparable solubilization on Py and inferior solubilization on Phen compared to all other investigated solubilizing systems. It is presumably attributed to the relationships between the structure of surfactants and the chemical nature of both solutes and surfactants. The analysis studied herein has provided valuable information for the selection of mixed Gemini surfactants for solubilizing water-insoluble compounds.


Chemosphere | 2012

Enhanced aqueous solubility of naphthalene and pyrene by binary and ternary Gemini cationic and conventional nonionic surfactants

Jia Wei; Guohe Huang; Lei Zhu; Shan Zhao; Chunjiang An; Y. R. Fan

A systematic study has been carried out to get insight into the micellar behavior of Gemini cationic and conventional nonionic in their single as well as equimolar bi and ternary mixed state using the technique of tensiometry. The models proposed by Clint, Rubingh and Motomura et al. have been employed to interpret the formation of mixed micelles and find out synergism. The obtained experimental CMCs are lower than the ideal CMCs, indicating negative deviation from ideal behavior for all multi-component mixed micelles formation. The solubilization capacities of selected equimolar bi and ternary surfactant systems towards polycyclic aromatic hydrocarbons (PAHs), naphthalene and pyrene, have been evaluated from measurements of the molar solubilization ratio (MSR), the micelle-water partition coefficient (K(m)), the deviation ratio (R) and the free energy of solubilization (ΔG(s)(0)) of PAHs. The results show that the solubility of naphthalene and pyrene over that in water in case of Gemini cationic surfactant is dramatically enhanced by adding equimolar nonionic surfactant in both bi and ternary mixed surfactant systems. The studied equimolar ternary surfactant system shows higher solubilizing efficiency than Gemini cationic binary system but lower than their cationic-nonionic counterpart. In addition, the solubilizing power of multi-component mixed surfactants towards naphthalene and pyrene increases with increasing logK(ow) of PAHs. Certainly, the solubilization abilities of the selected surfactants not only depend on their structure and mixing effect but also associate with solubilizing microenvironment and chemical nature of organic solutes.


Science of The Total Environment | 2017

Transport of anionic azo dyes from aqueous solution to gemini surfactant-modified wheat bran: Synchrotron infrared, molecular interaction and adsorption studies

Yan Zhang; Guohe Huang; Chunjiang An; Xiaying Xin; Xia Liu; Maya Raman; Yao Yao; Wenxia Wang; Mukesh Doble

From the view of economic efficiency and technology sustainability, biomass adsorbent has a high potential for pollution control. In the present study, the performance of gemini 12-2-12 surfactant-modified wheat bran (MWB) for the removal of anionic azo dyes from aqueous solution was investigated. A new insight was gained into the modification mechanism through synchrotron-assisted infrared analysis and molecular interaction simulation. The equilibrium and kinetic studies for the adsorption of Acid Red 18 (AR-18), Acid Orange 7 (AO-7) and Acid Black 1 (AB-1) on MWB were conducted. The Langmuir model well fit the adsorption isotherm data. The adsorption kinetics could be described by the pseudo-second-order and intra-particle diffusion models. The results of thermodynamic studies indicated the adsorption of AR-18 and AB-1 onto MWB was endothermic and spontaneous, while the adsorption of AO-7 was exothermic. The optimum pH for the adsorption of anionic azo dyes on MWB was 3. The adsorbed amount of anionic azo dyes onto MWB decreased when NaCl concentration increased from 0 to 0.4molL-1. The potential of modified wheat bran as a suitable adsorbent for the removal of dyes from wastewater was presented in this study. The results can help understand the migration patterns of organic pollutants at wheat bran-water interface.


Engineering Applications of Artificial Intelligence | 2014

Multi-objective ecological reservoir operation based on water quality response models and improved genetic algorithm

Ming Hu; Guohe Huang; Wei Sun; Yongping Li; Xiaowen Ding; Chunjiang An; Xiaofei Zhang; Ting Li

This study proposes a self-adaptive GA-aided multi-objective ecological reservoir operation model (SMEROM) and applies it to water quality management in the Xiangxi River near to the Three Gorges Reservoir, China. The SMEROM integrates statistical water quality models, multi-objective reservoir operations, and a self-adaptive GA within a general framework. Among them, the statistical water quality models of the Xiangxi River are formulated to deal with the relationships between reservoir operation and water quality, which are embedded in constraints of the SMEROM. The multiple objective functions, including maximizing hydropower generation, minimizing loss of flood control, minimizing rate of flood risk, maximizing the average remaining capacity of flood control and maximizing the benefit of shipping, are considered simultaneously to obtain comprehensive benefit among the environment, society and economy. The weighting method is employed to convert the multiple objectives to a single objective. To solve the complex SMEROM, an improved self-adaptive GA is employed through incorporating simulated binary crossover and self-adaptive mutation. To demonstrate the advantage of the developed SMEROM model, the solutions through ecological reservoir operation are compared with those through the traditional reservoir operation and the practical operation in 2011, in terms of water quality, reservoir operation and objective function values. The results show that most of benefit in the ecological operation is better than that in the traditional or practical operations except for the hydropower benefit and loss benefit of flood control. This is because flood control and environmental protection are reasonably considered in the ecological operation.

Collaboration


Dive into the Chunjiang An's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

Yao Yao

University of Regina

View shared research outputs
Top Co-Authors

Avatar

Jia Wei

Beijing University of Technology

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Hui Yu

Applied Science Private University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Xiaodong Zhang

University of Texas at Austin

View shared research outputs
Researchain Logo
Decentralizing Knowledge