Qingdao, China
Qingdao, China

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Tian W.,Ocean University of China | Tian W.,CAS Qingdao Institute of Oceanology | Qiao K.,Ocean University of China | Yu H.,Qingdao Water Group Co. | And 5 more authors.
Journal of Environmental Management | Year: 2016

In this paper, the modified coal cinders and zeolite powders in proportion of 2:1 were mixed with modified polyvinyl alcohol (PVA) with a ratio of 20:1 (w/v) to make a new sorbent and biological carrier-the coal cinder-zeolite balls (CCZBs). The maximum absorption capacities of ammonia nitrogen and Chemical Oxygen Demand (CODCr) on CCZBs, adsorption process were evaluated in batch experiments. And then they were combined with reed wetland for bioremediation of micro-polluted aquaculture water in estuarine wetlands. The results showed that the removal efficiencies of ammonia nitrogen and CODCr improved with the decrease in water inflow and increase in inflow concentrations. Efficiencies of 67.3% and 71.3% for ammonia nitrogen and CODCr under water flow of 10 L/h were obtained when their inflow concentrations were 1.77 and 56.0 mg/L respectively. This strategy can be served as a model system for bioremediation in situ of aquaculture water and other organic polluted or eutrophic water. © 2016 Elsevier Ltd

Gu Y.,China University of Petroleum - East China | Fu R.,Shanghai Academy of Environmental science | Li H.,Qingdao Water Group Co.
Huagong Xuebao/CIESC Journal | Year: 2014

Batch desorption and bench-scale electrochemical remediation experiments were conducted to investigate the feasibility of using citric acid industrial wastewater (CAIW) as the enhancement agent to extract cadmium from natural soil of high buffer capacity. The results of the desorption experiments indicated that it was very difficult to dissolve cadmium without any enhancement agent when the soil pH was above 7.0. The addition of CAIW, however, could make more than 85% of the sorbed cadmium dissolved into solution at pH ≤ 5.0. The proportion of cadmium desorption was 20%-45% higher with the enhancement of CAIW compared with DI water at pH 5.0-8.0. The results of the electrochemical remediation experiments showed that CAIW as the electrolyte could cause significant migration of cadmium in soil compared with HNO3 solution of the same pH. Cadmium concentration in soil samples at 0-4 cm and 8-10 cm from the anode decreased to approximately 167-200 mg·kg-1 from the initial value of 282 mg·kg-1, while it increased to 400 mg·kg-1 at 4-8 cm from the anode. Approximately 84.7% of the spiked cadmium could be removed after 514 h of electrochemical treatment enhanced by CAIW. Approximately 94.6% of the removed cadmium was collected in the catholyte. It is concluded that CAIW can be a promising alternative for other expensive metal chelating agents for enhancing electrochemical remediation of heavy metal-contaminated soils of high buffer capacities. © All Rights Reserved.

Gu Y.,China University of Petroleum - East China | Fu R.,Shanghai Academy of Environmental science | Li H.,Qingdao Water Group Co. | An H.,China University of Petroleum - East China
Chinese Journal of Chemical Engineering | Year: 2015

Electrochemical extraction of contaminants from soils is a promising soil decontamination technology. Various experiments have been conducted to study electrochemical reactions and geochemical processes in the electrochemical extraction using different experimental apparatuses. This paper presents the development of a new closed two-dimensional (2D) apparatus that can better simulate the field application of the technology and accurately monitor the most important electrochemical parameters to understand the process. The innovative features of the new apparatus include the outer and inner electrodes designed to apply a non-uniform electrical field across the specimen as in the field electrochemical remediation process, the probes installed to measure the 2D distribution of electrical voltage, and the gas and fluid volume measurement devices used to accurately monitor the gas generation and electroosmotic flow rates at both electrodes as a function of time. The components of this new apparatus and the features of each component are described. The operating procedure and some typical results from three experiments with the apparatus are demonstrated. The results show that the variation of the gas generation rate is in good agreement with the electric current. Their relation provides a valid evaluation for electrochemical behavior of the system and Faraday's laws of electrolysis. The 2D profiles of cadmium concentration and voltage distribution at the end of the experiment reveal the great effects of a non-uniform electrical field on the contaminant mobilization. © 2015 Elsevier B.V.

Sun Y.,Shandong University | Sun Y.,Qingdao Water Group Co. | Zhang F.,Shandong University | Xu L.,Shandong University | And 2 more authors.
Journal of Materials Chemistry A | Year: 2014

Effective surface and interface control of metal nanomaterials provides a powerful tool for achieving their enhanced catalytic properties. This article reports a remarkably simple approach for the preparation of copper nanowires with a rough surface. Surface roughness of Cu nanowires can be successfully controlled by adjusting the reactant ratio of the same type of element ions with different valence state (Cu+ and Cu2+). Furthermore, it is noted that the as-prepared rough Cu nanowires have higher BET surface areas and a porous structure with a total pore volume of 4.212 nm. Cu nanowires-Ag heterostructures are further prepared using the as-prepared rough Cu wires as the "substrate". Our experimental results reveal that Ag nanocrystals preferentially grow on nanowires with a rough surface morphology compared to smooth nanowires. Due to the surface effects and synergistic effect of their constituents, the as-prepared rough copper nanowires and Cu nanowires-Ag heterostructures demonstrated highly enhanced catalytic performance for the reduction of 4-nitrophenol. In particular, the Cu nanowires-Ag heterostructures show superior catalytic activity than the as-obtained Cu nanowires with smooth surface, and some recently reported noble metal catalysts, such as pure Ag nanowires, magnetic Au nanocrystals, and Au/graphene hydrogel. This study offers a simple strategy that could be applied for the fabrication of other promising one dimensional Cu-based bimetallic nanomaterials. © the Partner Organisations 2014.

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