Entity

Time filter

Source Type


Zhu L.,Zhejiang University | Lin H.-Z.,Zhejiang University | Lin H.-Z.,Wenzhou Environmental Protection Design Scientific Institute | Qi J.-Q.,Zhejiang University | And 3 more authors.
Water Research | Year: 2012

Using a combined zero-valent iron (ZVI) and anaerobic sludge system as the platform, the hydrogen utilization and reductive mechanism of p-chloronitrobenzene (p-ClNB) were investigated in the study. Results showed that the corrosion of ZVI could be used as a source of electron donor for anaerobic microorganisms, and then enhanced reductive transformation of p-ClNB and production of methane. Thereinto, the transformation of p-ClNB was observed to have priority for the utilization of H 2. The enhancement factors (Q') for the reductive transformation of p-ClNB with exogenous H 2, reduced ZVI (RZVI), industrial ZVI (IZVI), and nanoscale ZVI (NZVI) as electron donors were 4.1-5.6, 14.8-35.1, 2.8-4.6, and 1.5-5.7, respectively. Results demonstrated that RZVI was the most effective type of electron donors, which was attributed to the production and utilization of H 2/[H] simultaneously via the ZVI corrosion and microbial metabolism. It is hopeful for the application of ZVI to enhance the reductive transformation of analogous persistent organic pollutants in the anaerobic sludge system. © 2012 Elsevier Ltd.


Zhu L.,Zhejiang University | Lin H.,Zhejiang University | Lin H.,Wenzhou Environmental Protection Design Scientific Institute | Qi J.,Zhejiang University | And 2 more authors.
Environmental Science and Pollution Research | Year: 2013

The combination of zero-valent iron (ZVI) with anaerobic sludge for enhancing reductive transformation and dechlorination of p-chloronitrobenzene (p-ClNB) was investigated in this study. p-ClNB was quickly reduced into p-chloroaniline (p-ClAn) and subsequently dechlorinated into aniline in the complex system, and the strengthening factor for pseudo-first-order transformation rate constant of p-ClNB (Q, k ZVI + sludge/(k sludge + k ZVI)) was above 3. The Q values for the different ZVI types with anaerobic sludge were as following: Reduced ZVI (RZVI) > Industrial ZVI > Nanoscale ZVI (NZVI). Thereinto, the aggregation of NZVI occurred, and its reaction activity declined. Furthermore, the increase of ZVI dosage promoted the p-ClNB transformation, but the p-ClAn dechlorination rate and Q value were not improved. With the anaerobic biomass increasing, the dechlorination rate of p-ClAn was significantly enhanced, and the Q value had positive relation with the mass ratio of anaerobic sludge to RZVI. © 2013 Springer-Verlag Berlin Heidelberg.


Zhu L.,Zhejiang University | Zhu L.,Zhejiang Province Key Laboratory for Water Pollution Control and Environmental Safety | Gao K.,Zhejiang University | Jin J.,Zhejiang University | And 4 more authors.
Environmental Science and Pollution Research | Year: 2014

The zero-valent iron (ZVI) corrosion products and their functions were investigated in the combined ZVI and anaerobic sludge system. Results showed that ZVI corrosion occurred, and the reductive transformation and dechlorination of p-chloronitrobenzene (p-ClNB) by the anaerobic sludge were enhanced. In the combined systems with different types of ZVIs and mass ratios of anaerobic sludge to ZVI, a considerable amount of suspended iron compounds was produced and coated onto the microbial cells. However, the microbial cellular structure was damaged, and the p-ClNB reductive transformation was affected adversely after the long-term presence of nanoscale ZVI (NZVI) or reduced ZVI (RZVI) with a high concentration of 5 g L−1. The oxidized products of FeOOH and Fe3O4were found on the surface of ZVI, which are speculated to act as electron mediators and consequently facilitate the utilization of electron donors by the anaerobic microbes. © 2014, Springer-Verlag Berlin Heidelberg.


Zhu L.,Zhejiang University | Zhu L.,Zhejiang Province Key Laboratory for Water Pollution Control and Environmental Safety | Jin J.,Zhejiang University | Lin H.,Zhejiang University | And 4 more authors.
Journal of Hazardous Materials | Year: 2015

The combined zero-valent iron (ZVI) and upflow anaerobic sludge blanket (UASB) process is established for the treatment of chloronitrobenzenes (ClNBs) wastewater, and the succession of microbial community and its enhanced mechanism are investigated in the study. Results showed that compared with the control UASB (R1), the stable COD removal, ClNBs transformation, and dechlorination occurred in the combined system (R2) when operated at influent COD and 3,4-Dichloronitrobenzene (3,4-DClNB) loading rates of 4200-7700gm-3d-1 and 6.0-70.0gm-3d-1, and R2 had the better shock resistance and buffering capacity for the anaerobic acidification. The dechlorination for the intermediate products of p-chloroanaline (p-ClAn) to analine (AN) occurred in R2 reactor after 45 days, whereas it did not occur in R1 after a long-term operation. The novel ZVI-based anaerobic granular sludge (ZVI-AGS) was successfully developed in the combined system, and higher microbial activities including ClNB transformation and H2/CH4 production were achieved simultaneously. The dominant bacteria were closely related to the groups of Megasphaera, Chloroflexi, and Clostridium, and the majority of archaea were correlated with the groups of Methanosarcinalesarchaeon, Methanosaetaconcilii, and Methanothrixsoehngenii, which are capable of reductively dechlorinating PCB, HCB, and TCE in anaerobic niche and EPS secretion. © 2014 Elsevier B.V.

Discover hidden collaborations