National Engineering Research Center for Control and Treatment of Heavy Metal Pollution

Changsha, China

National Engineering Research Center for Control and Treatment of Heavy Metal Pollution

Changsha, China
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Chai L.-Y.,Central South University | Chai L.-Y.,National Engineering Research Center for Control and Treatment of Heavy Metal Pollution | Mubarak H.,Central South University | Mubarak H.,National Engineering Research Center for Control and Treatment of Heavy Metal Pollution | And 9 more authors.
Environmental Science and Pollution Research | Year: 2015

Ramie (Boehmeria nivea L.) is the oldest cash fiber crop in China and is widely grown in antimony (Sb) mining areas. To evaluate the extent of Sb resistance and tolerance, the growth, tolerance index (TI), Sb content in plant parts and in Hoagland solution, bioaccumulation factor (BF), photosynthesis, and physiological changes in Sb-contaminated B. nivea (20, 40, 80, and 200 mg L−1 Sb) grown hydroponically were investigated. The Sb tolerance and resistance of ramie were clearly revealed by growth inhibition, a TI between 13 and 99 %, non-significant changes in the maximum quantum efficiency of photosystem (Fv/Fm), energy-harvesting efficiency (photosystem II (PSII)) and single-photon avalanche diode (SPAD) value, a significant increase in Sb in plant parts, BF >1, and an increase in catalase (CAT) and malondialdehyde (MDA) at 200 mg L−1 Sb. Under increasing Sb stress, nearly the same non-significant decline in the maximum quantum efficiency of photosystem (Fv/Fm), energy-harvesting efficiency (PSII), relative quantum yield of photosystem II (φPSII), and photochemical quenching (qP), except for Fv/Fm at 20 mg L−1 Sb, were recorded. SPAD values for chlorophyll under Sb stress showed an increasing trend, except for a slight decrease, i.e., <2 %, than the control SPAD value at 200 mg L−1 Sb. With a continuous increase in MDA, superoxide dismutase (SOD), peroxidase (POD), and CAT activities were suppressed under Sb addition up to 40 mg L−1 Sb and the addition of Sb enhanced enzyme production at 80 and 200 mg L−1 Sb. A continuous decrease in SOD, POD, and CAT up to 40 mg L−1 Sb and enhancements at ≥80 mg L−1, along with the continuous enhancement of MDA activity and inhibited biomass production, clearly reveal the roles of these enzymes in detoxifying Sb stress and the defense mechanism of ramie at 80 mg L−1 Sb. Thus, B. nivea constitutes a promising candidate for Sb phytoremediation at mining sites. © 2015 Springer-Verlag Berlin Heidelberg


Ali M.,Central South University | Ali M.,National Engineering Research Center for Control and Treatment of Heavy Metal Pollution | Chai L.-Y.,Central South University | Chai L.-Y.,National Engineering Research Center for Control and Treatment of Heavy Metal Pollution | And 11 more authors.
BioMed Research International | Year: 2013

Nitrogen pollution created severe environmental problems and increasingly has become an important issue in China. Since the first discovery of ANAMMOX in the early 1990s, this related technology has become a promising as well as sustainable bioprocess for treating strong nitrogenous wastewater. Many Chinese research groups have concentrated their efforts on the ANAMMOX research including bacteria, process development, and application during the past 20 years. A series of new and outstanding outcomes including the discovery of new ANAMMOX bacterial species (Brocadia sinica), sulfate-dependent ANAMMOX bacteria (Anammoxoglobus sulfate and Bacillus benzoevorans), and the highest nitrogen removal performance (74.3-76.7 kg-N/m3/d) in lab scale granule-based UASB reactors around the world were achieved. The characteristics, structure, packing pattern and floatation mechanism of the high-rate ANAMMOX granules in ANAMMOX reactors were also carefully illustrated by native researchers. Nowadays, some pilot and full-scale ANAMMOX reactors were constructed to treat different types of ammonium-rich wastewater including monosodium glutamate wastewater, pharmaceutical wastewater, and leachate. The prime objective of the present review is to elucidate the ongoing ANAMMOX research in China from lab scale to full scale applications, comparative analysis, and evaluation of significant findings and to set a design to usher ANAMMOX research in culmination. © 2013 Mohammad Ali et al.


Tang C.-J.,Central South University | Tang C.-J.,Zhejiang University | Tang C.-J.,National Engineering Research Center for Control and Treatment of Heavy metal Pollution | Zheng P.,Zhejiang University | And 4 more authors.
Chemical Engineering Journal | Year: 2013

The long-term effects and mechanism of organic matter on ANAMMOX process was comparatively investigated by operating two SBRs. SBR1 was operated under inorganic conditions with an efficient and stable ANAMMOX performance. The autotrophic nitrogen removal performance of SBR2 gradually deteriorated and finally disappeared when influent COD concentration was progressively increased to 800. mg/L during the 220 cycles' operation. After dosing organic matter, the ANAMMOX activity of SBR2 biomass decreased to 1/4 of that of SBR1 sludge. Intensive denitrification and sulfate reduction were observed under the long-term exposure to organic matter. The denitrification and sulfate-reduction activities of SBR2 sludge finally developed to 4 and 16 times of the values of SBR1 biomass, respectively. Thermodynamic and kinetic analyses showed that both denitrification and sulfate reduction were enhanced under the high organic conditions. ANAMMOX bacteria could be eliminated from the SBR system due to preferential metabolization of nitrite by denitrification and, thus causing starvation of ANAMMOX bacteria. © 2013 Elsevier B.V.


Tang C.-J.,Central South University | Tang C.-J.,National Engineering Research Center for Control and Treatment of Heavy Metal Pollution | Tang C.-J.,Zhejiang University | Zheng P.,Zhejiang University | And 4 more authors.
International Biodeterioration and Biodegradation | Year: 2013

The start-up of anammox process inoculated with anaerobic granular sludge and nitritation sludge were carefully investigated in two upflow anaerobic sludge blanket (UASB) reactors. Three major bioprocesses related in anammox start-up i.e. anammox, denitrification and cell lysis, were quantified in both reaction and microbial growth aspects in the four consecutive phases namely cell lysis phase, lag phase, activity elevation phase and stationary phase. The results showed that anammox was negligible when cell lysis was predominant in the reactors; however, the density of anammox bacteria objectively increased in this phase due to the biomass reduction caused by hydrolysis. During lag phase, poor anammox was detected; while denitrification and cell lysis were the two leading reactions. Anammox performance of the reactors was significantly enhanced in activity elevation phase. Denitrification continuously weakened in stationary phase and anammox gradually became the dominant reaction. Nevertheless, heterotrophic denitrification still predominated throughout the start-up course due to the extremely low growth rate of anammox bacteria. Results also suggested that the inoculation strategy using nitritation sludge as the main inoculum commixing with anaerobic granular sludge could contribute to the relatively shorter start-up time and better reactor performance. Such an alternative may prove effective strategy for full-scale application of anammox process. © 2013 Elsevier Ltd.


Tang C.-J.,Central South University | Tang C.-J.,National Engineering Research Center for Control and Treatment of Heavy Metal Pollution | He R.,Zhejiang University | Zheng P.,Zhejiang University | And 4 more authors.
Journal of Hazardous Materials | Year: 2013

A novel mathematical model was developed to estimate the volumetric nitrogen conversion rates of a high-rate Anammox UASB reactor based on the packing patterns of granular sludge. A series of relationships among granular packing density, sludge concentration, hydraulic retention time and volumetric conversion rate were constructed to correlate Anammox reactor performance with granular packing patterns. It was suggested that the Anammox granules packed as the equivalent simple cubic pattern in high-rate UASB reactor with packing density of 50-55%, which not only accommodated a high concentration of sludge inside the reactor, but also provided large pore volume, thus prolonging the actual substrate conversion time. Results also indicated that it was necessary to improve Anammox reactor performance by enhancing substrate loading when sludge concentration was higher than 37.8. gVSS/L. The established model was carefully calibrated and verified, and it well simulated the performance of granule-based high-rate Anammox UASB reactor. © 2013 Elsevier B.V.


Tang C.-J.,Central South University | Tang C.-J.,National Engineering Research Center for Control and Treatment of Heavy Metal Pollution | Xiong L.,Central South University | Xiong L.,National Engineering Research Center for Control and Treatment of Heavy Metal Pollution | And 3 more authors.
Huanjing Kexue/Environmental Science | Year: 2013

The high-rate ANAMMOX granules (HAG) were cultivated in an ANAMMOX upflow anaerobic sludge blanket (UASB) reactor. The kinetic characteristics of the HAG were investigated through batch tests, using flocculent ANAMMOX sludge (FAS) as a control. The results suggested that the specific ANAMMOX activity (SAA) of the HAG reached as high as 2.63 kg · (kg · d)-1, which was 2.5 times of that of FAS. The half saturation constants for ammonium and nitrite of the HAG were 17 mg · L-1 and 19 mg · L-1, respectively, both were lower than those of the FAS. The half inhibition constants of ammonium, free ammonia and nitrite were 11 679, 505 and 735 mg · L-1, respectively, which were far higher than the corresponding values of the FAS. The better kinetic performance of the HAG contributed to the successful competition of substrates under tough conditions, which was helpful for the novel biomass supplementation process for enhancement of the ANAMMOX performance.


Ali M.,Central South University | Ali M.,National Engineering Research Center for Control and Treatment of Heavy Metal Pollution | Chai L.-Y.,Central South University | Chai L.-Y.,National Engineering Research Center for Control and Treatment of Heavy Metal Pollution | And 13 more authors.
Biodegradation | Year: 2016

The short-cut nitrification (SCN) performance of an airlift reactor (ALR) was investigated under increasing bicarbonate condition. The sequential increase of bicarbonate from 2.5 to 7.0 g/L accelerated the nitrite accumulation and improved the NAP to 99 %. With the increase of bicarbonate dose to 11 g/L, the ammonium removal efficiency and the ammonium removal rate (ARR) were improved to 95.1 % and 0.57 kg/m3/day, respectively. However, the elevation of bicarbonate concentration from 11.0 to 14.0 g/L gradually depreciated the nitrite accumulation percentage to 62.5 %. Then, the reactor was operated in increasing ammonium strategy to increase the nitrogen loading rate (NLR) to 1.1 kg/m3/day under 700 mg/L influent ammonium concentration. The ARR and nitrite production rate were elevated to 1.1 and 0.9 kg/m3/day, respectively. The SCN performance was improved to 1.8 kg/m3/day (NLR) by the subsequent progressive shortening of HRT to 4.8 h at ammonium concentration of 350 mg/L, which was 1.6 times higher than that of the increasing ammonium strategy. Chemical analysis with EDS, FTIR and XRD confirmed the presence of CaCO3 precipitates on biomass surface during the long-term operation under high bicarbonate conditions. The attachment of precipitates to the SCN sludge helped to improve the biomass settleability and finally enhanced the SCN performance of the ALR. © 2016 Springer Science+Business Media Dordrecht


Chai L.-Y.,Central South University | Chai L.-Y.,National Engineering Research Center for Control and Treatment of Heavy Metal Pollution | Ali M.,Central South University | Ali M.,National Engineering Research Center for Control and Treatment of Heavy Metal Pollution | And 12 more authors.
Bioresource Technology | Year: 2015

The partial nitrification (PN) performance under high ammonium concentrations was evaluated in an airlift reactor (ALR). The ALR was operated for 253days with stepwise elevation of ammonium concentration to 1400mg/L corresponding nitrogen loading rate of 2.1kg/m3/d. The ammonium removal rate was finally developed to 2.0kg/m3/d with average removal efficiency above 91% and nitrite accumulation percentage of 80%. Results showed that the combined effect of limited DO, high bicarbonate, pH and free ammonia (FA) contributed to the stable nitrite accumulation substantially. The biomass in the ALR was improved with the inception of granulation. Precipitates on biomass surface was unexpectedly experienced which might improve the settleability of PN biomass. Organic functional groups attached to the PN biomass suggested the possible absorbability to different types of pollutant. The results provided important evidence for the possibility of applying an ALR to treat high strength ammonium wastewater. © 2015 Elsevier Ltd.


Zhu J.M.,Central South University | Li G.,Central South University | Jiang L.Y.,Central South University | Jiang L.Y.,National Engineering Research Center for Control and Treatment of Heavy Metal Pollution
Journal of Applied Polymer Science | Year: 2016

A series of polysiloxaneimide (PSI)/polyetherimide (PEI) composite hollow fibers were fabricated by coextrusion and phase inversion. The hydrophobic PSI outer layer was set as the selective layer which was supported by the PEI inner layer. The PSI was synthesized by polycondensation of 3,3′,4,4′-Biphenyltetracarboxylic Dianhydride (BPDA) with amino siloxane X-22-161A and a chain extender, 1,3-Bis (3-aminopropyl) -1,1,3,3-tertramethyldisiloxane (BATS). It was found that the macroscopic uniformity of PSI layer was dependent on the dope formulation, coagulant composition and dope flow rate: (1) the higher similarity degree of the solvent(s) for different layers in terms of solubility parameters, (2) the utilization of surfactant as a component in the water coagulant, and (3) higher flow rates of the outer layer dopes, led to the formation of more uniform and smoother PSI outer layer. The maximum outer layer thickness was around 2 μm. The bulk of the PEI layers were porous with finger like macrovoids. The outer surface of the inner PEI layer for some batches of the hollow fibers was confirmed to be porous. The original dual-layer hollow fibers showed poor pervaporation performance. Post treatment was applied to cure the hollow fiber, delivering composite membranes with performance dominated by the coating material of PDMS. © 2016 Wiley Periodicals, Inc.


Yu C.,Central South University | Yu C.,National Engineering Research Center for Control and Treatment of Heavy Metal Pollution | Song Y.-X.,Central South University | Song Y.-X.,National Engineering Research Center for Control and Treatment of Heavy Metal Pollution | And 10 more authors.
Journal of Bioscience and Bioengineering | Year: 2016

Batch experiments were conducted to investigate the short-term effects of Cd(II), Hg(II), Pb(II), As(III) and Cr(VI) on anammox activity, which are considered to be the top 5 toxic heavy metals in China. The IC50 values of Cd(II), Hg(II), Pb(II) and Cr(VI) were calculated to be 7.00, 2.33, 10.40 and 9.84 mg/L, respectively, while As(III) caused only 29.67% decrease in SAA even at the dosage of 60 mg/L. The evaluation of metal concentrations in liquid and sludge revealed that anammox biomass hold a high heavy-metal accumulation ability, which was hypothesized to be the key reason of activity inhibition. The functional groups possessed by anammox biomass and the extracellular polymeric substance (EPS) might contribute to the attachment of heavy metals. Especially, microbial reduction of Cr(VI) to Cr(III) inside the granules was discovered, which was considered to relieve the Cr(VI) inhibition under concentrations lower than 8.96 mg/L. © 2016.

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