scholarly journals Reductive/Oxidative Sequential Bioelectrochemical Process for Perchloroethylene Removal

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2579 ◽  
Author(s):  
Zeppilli ◽  
Dell’Armi ◽  
Cristiani ◽  
Petrangeli Papini ◽  
Majone

An innovative bioelectrochemical reductive/oxidative sequential process was developed and tested on a laboratory scale to obtain the complete mineralization of perchloroethylene (PCE) in a synthetic medium. The sequential bioelectrochemical process consisted of two separate tubular bioelectrochemical reactors that adopted a novel reactor configuration, avoiding the use of an ion exchange membrane to separate the anodic and cathodic chamber and reducing the cost of the reactor. In the reductive reactor, a dechlorinating mixed inoculum received reducing power to perform the reductive dechlorination of perchloroethylene (PCE) through a cathode chamber, while the less chlorinated daughter products were removed in the oxidative reactor, which supported an aerobic dechlorinating culture through in situ electrochemical oxygen evolution. Preliminary fluid dynamics and electrochemical tests were performed to characterize both the reductive and oxidative reactors, which were electrically independent of each other, with each having its own counterelectrode. The first continuous-flow potentiostatic run with the reductive reactor (polarized at −450 mV vs SHE) resulted in obtaining 100% ± 1% removal efficiency of the influent PCE, while the oxidative reactor (polarized at +1.4 V vs SHE) oxidized the vinyl chloride and ethylene from the reductive reactor, with removal efficiencies of 100% ± 2% and 92% ± 1%, respectively.

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 272
Author(s):  
Ayman M. Atta ◽  
Mohamed H. El-Newehy ◽  
Meera Moydeen Abdulhameed ◽  
Mohamed H. Wahby ◽  
Ahmed I. Hashem

The enhancement of both thermal and mechanical properties of epoxy materials using nanomaterials becomes a target in coating of the steel to protect it from aggressive environmental conditions for a long time, with reducing the cost. In this respect, the adhesion properties of the epoxy with the steel surfaces, and its proper superhyrophobicity to repel the seawater humidity, can be optimized via addition of green nanoparticles (NPs). In-situ modification of silver (Ag) and calcium carbonate (CaCO3) NPs with oleic acid (OA) was carried out during the formation of Ag−OA and CaCO3−OA, respectively. The epoxide oleic acid (EOA) was also used as capping for Ca−O3 NPs by in-situ method and epoxidation of Ag−OA NPs, too. The morphology, thermal stability, and the diameters of NPs, as well as their dispersion in organic solvent, were investigated. The effects of the prepared NPs on the exothermic curing of the epoxy resins in the presence of polyamines, flexibility or rigidity of epoxy coatings, wettability, and coatings durability in aggressive seawater environment were studied. The obtained results confirmed that the proper superhyrophobicity, coating adhesion, and thermal stability of the epoxy were improved after exposure to salt spray fog for 2000 h at 36 °C.


Author(s):  
Tingting Li ◽  
Tianyun Jing ◽  
Dewei Rao ◽  
Xiaotian Jia ◽  
Yunpeng Zuo ◽  
...  

Multimetallic pyrite-type sulfides have been a promising electrocatalytic materials for electrochemical oxygen evolution reaction (OER), but still requires further improve due to the easily oxidization of surface atoms and the...


Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 405
Author(s):  
Edoardo Dell’Armi ◽  
Marco Zeppilli ◽  
Bruna Matturro ◽  
Simona Rossetti ◽  
Marco Petrangeli Papini ◽  
...  

Chlorinated aliphatic hydrocarbons (CAHs) are common groundwater contaminants due to their improper use in several industrial activities. Specialized microorganisms are able to perform the reductive dechlorination (RD) of high-chlorinated CAHs such as perchloroethylene (PCE), while the low-chlorinated ethenes such as vinyl chloride (VC) are more susceptible to oxidative mechanisms performed by aerobic dechlorinating microorganisms. Bioelectrochemical systems can be used as an effective strategy for the stimulation of both anaerobic and aerobic microbial dechlorination, i.e., a biocathode can be used as an electron donor to perform the RD, while a bioanode can provide the oxygen necessary for the aerobic dechlorination reaction. In this study, a sequential bioelectrochemical process constituted by two membrane-less microbial electrolysis cells connected in series has been, for the first time, operated with synthetic groundwater, also containing sulphate and nitrate, to simulate more realistic process conditions due to the possible establishment of competitive processes for the reducing power, with respect to previous research made with a PCE-contaminated mineral medium (with neither sulphate nor nitrate). The shift from mineral medium to synthetic groundwater showed the establishment of sulphate and nitrate reduction and caused the temporary decrease of the PCE removal efficiency from 100% to 85%. The analysis of the RD biomarkers (i.e., Dehalococcoides mccartyi 16S rRNA and tceA, bvcA, vcrA genes) confirmed the decrement of reductive dechlorination performances after the introduction of the synthetic groundwater, also characterized by a lower ionic strength and nutrients content. On the other hand, the system self-adapted the flowing current to the increased demand for the sulphate and nitrate reduction, so that reducing power was not in defect for the RD, although RD coulombic efficiency was less.


Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 275
Author(s):  
Chung Yiin Wong ◽  
Kunlanan Kiatkittipong ◽  
Worapon Kiatkittipong ◽  
Seteno K. O. Ntwampe ◽  
Man Kee Lam ◽  
...  

Oftentimes, the employment of entomoremediation to reduce organic wastes encounters ubiquitous shortcomings, i.e., ineffectiveness to valorize recalcitrant organics in wastes. Considering the cost-favorability, a fermentation process can be employed to facilitate the degradation of biopolymers into smaller organics, easing the subsequent entomoremediation process. However, the efficacy of in situ fermentation was found impeded by the black soldier fly larvae (BSFL) in the current study to reduce coconut endosperm waste (CEW). Indeed, by changing into ex situ fermentation, in which the fungal Rhizopus oligosporus was permitted to execute fermentation on CEW prior to the larval feeding, the reduction of CEW was significantly enhanced. In this regard, the waste reduction index of CEW by BSFL was almost doubled as opposed to in situ fermentation, even with the inoculation of merely 0.5 wt % of Rhizopus oligosporus. Moreover, with only 0.02 wt % of fungal inoculation size to execute the ex situ fermentation on CEW, it could spur BSFL growth by about 50%. Finally, from the statistical correlation study using principal component analysis, the presence of Rhizopus oligosporus in a range of 0.5–1.0 wt % was regarded as optimum to ferment CEW via ex situ mode, prior to the valorization by BSFL in reducing the CEW.


Desalination ◽  
2006 ◽  
Vol 200 (1-3) ◽  
pp. 173-174 ◽  
Author(s):  
Patrice Huguet ◽  
Philippe Sistat ◽  
Stefano Deabate ◽  
Eddy Petit

Author(s):  
Munzer S. Y. Ebaid ◽  
Mohamad Y. Mustafa

The design of the fuel cell plays a major role in determining their cost. It is not only the cost of materials that increases the cost of the fuel cell, but also the manufacturing techniques and the need for skilled technicians for assembling and testing the fuel cell. The work presented in this paper is part of a research work aims to design and manufacture a proton exchange membrane (PEM) modular fuel cell of 100 W output at low cost using conventional materials and production techniques, then testing the fuel cell to validate its performance. This paper will be dealing only with the design of a modular fuel cell that can be mass produced and used to set up a larger fuel cell stack for stationary applications (6 kW) which is capable of powering a medium sized household. The design for 100 W fuel cell module will include the calculations for the main dimensions of the fuel cell components, mass flow rate of reactants, water production, heat output, heat transfer and the cooling system. This work is intended to facilitate material and process selection prior to manufacturing alternatives prior to capital investment for wide-scale production. The authors believe that the paper would lead to a stimulating discussion.


The Precast industry is booming industry now a day, but then also the implementation ratio of precast member in residential construction work is not up to the mark. As we all know that precast having numerous advantages over the cast in situ construction method, for example it saves the total time of construction which indirectly reduces the cost of construction but still we are lagging behind in implementation of precast in it. In this research we have listed out some problem which can be cause of less implementation of precast in residential construction buildings. As discussed in paper, there are so many factors are affected on Implementation of Precast in Residential Construction Sector For example: Technical Issues and General Issues. In Technical Issues Joint stability problem during Erection, Standard size of precast element, Leakage Issues, Design change related problem, Requirement of Standard Rate per Panel, End user Profit, Additional Taxes, General Issues are: Transportation of Precast Element, Loading and Unloading problems, Transportation to sight, Storage Area, Skilled Labour Research has done and data is collected through Questionery survey, Field survey, and research survey.


2015 ◽  
Vol 31 (8) ◽  
pp. 1609-1614
Author(s):  
Ming-Feng. SHANG ◽  
◽  
Pei-Quan. DUAN ◽  
Tian-Tian. ZHAO ◽  
Wen-Chao. TANG ◽  
...  

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