Electrodialytic (ED) recovery of citric acid (CA) in the presence/absence of strong electrolytes (NaCl, CaCl2 and Feel3) was separately analyzed under different process conditions. Recovery effectiveness was qua...Electrodialytic (ED) recovery of citric acid (CA) in the presence/absence of strong electrolytes (NaCl, CaCl2 and Feel3) was separately analyzed under different process conditions. Recovery effectiveness was quantitatively estimated from current efficiency values. Efficiency attained optimum value with both flow rate and potential applied, while a monotonic rise was noted with temperature which got lowered beyond 0.1 tool. L 1 feed concentration. 40% drop in efficiency was recorded in the presence of strong electrolytes (Noel, CaCl2 and Feel3) in feed relative to their presence in concentrate. Severe transport hindrance and efficiency loss were attributed to adsorption and allied physicochemical changes occurred with anion/cation exchange membranes (AEM/CEM) and these were confirmed through contact angle/Chronopotentiometry/AFM/EDX. Sluggish potential rise (Galvanostatic mode) in Chronopotentiometric analysis indicated diffusion limiting transport of organic acids influenced AEM resistance. XRD and EDX analysis indicated the presence of salt hydrates/ions (Ca2+/Fe3+) over CEM justifying the resistance buildup due to adsorption of multivalent metal ion(s) and salts.展开更多
To separate and concentrate NH4+ and PO43 from the synthetic wastewater to the concentrated solution through a novel electrochemical reactor with circulated anode and cathode using the difference of the concentration...To separate and concentrate NH4+ and PO43 from the synthetic wastewater to the concentrated solution through a novel electrochemical reactor with circulated anode and cathode using the difference of the concentration between electrode chamber and middle chamber.In recent years, the research on electrochemical processes have been focused on phosphate and ammonium removal and recovery. Among the wide range of possibilities with regards to electrochemical processes, capacitive deionization (CDI) saves the most energy while at the same time does not have continuity and selectivity. In this study, a new electrochemical reactor with electrolyte cyclic flowing in the electrode chambers was constructed to separate and concentrate phosphate and ammonium continuously and selectively from wastewater, based on the principle of CDI. At the concentration ratio of NaCI solution between the electrode chambers and the middle chamber (r) of 25 to 1, phosphate and ammonium in concentration level of domestic wastewater can be removed and recovered continuously and selectively as struvite. Long-term operation also indicated the ability to continuously repeat the reaction and verified sustained stability. Further, the selective recovery at the certain r could also be available to similar technologies for recovering other kinds of substances.展开更多
基金Financial support to execute the experimental work is gratefully acknowledged to IIT Roorkee(No.IITR/SRIC/244/FIG-Sch-A)UAY Project(ICSR/UAY/2016/SN dt 04/01/2017),India
文摘Electrodialytic (ED) recovery of citric acid (CA) in the presence/absence of strong electrolytes (NaCl, CaCl2 and Feel3) was separately analyzed under different process conditions. Recovery effectiveness was quantitatively estimated from current efficiency values. Efficiency attained optimum value with both flow rate and potential applied, while a monotonic rise was noted with temperature which got lowered beyond 0.1 tool. L 1 feed concentration. 40% drop in efficiency was recorded in the presence of strong electrolytes (Noel, CaCl2 and Feel3) in feed relative to their presence in concentrate. Severe transport hindrance and efficiency loss were attributed to adsorption and allied physicochemical changes occurred with anion/cation exchange membranes (AEM/CEM) and these were confirmed through contact angle/Chronopotentiometry/AFM/EDX. Sluggish potential rise (Galvanostatic mode) in Chronopotentiometric analysis indicated diffusion limiting transport of organic acids influenced AEM resistance. XRD and EDX analysis indicated the presence of salt hydrates/ions (Ca2+/Fe3+) over CEM justifying the resistance buildup due to adsorption of multivalent metal ion(s) and salts.
基金This research was supported by the Key Program of the National Natural Science Foundation of China (Grant Nos. 51238004 & 21521064).
文摘To separate and concentrate NH4+ and PO43 from the synthetic wastewater to the concentrated solution through a novel electrochemical reactor with circulated anode and cathode using the difference of the concentration between electrode chamber and middle chamber.In recent years, the research on electrochemical processes have been focused on phosphate and ammonium removal and recovery. Among the wide range of possibilities with regards to electrochemical processes, capacitive deionization (CDI) saves the most energy while at the same time does not have continuity and selectivity. In this study, a new electrochemical reactor with electrolyte cyclic flowing in the electrode chambers was constructed to separate and concentrate phosphate and ammonium continuously and selectively from wastewater, based on the principle of CDI. At the concentration ratio of NaCI solution between the electrode chambers and the middle chamber (r) of 25 to 1, phosphate and ammonium in concentration level of domestic wastewater can be removed and recovered continuously and selectively as struvite. Long-term operation also indicated the ability to continuously repeat the reaction and verified sustained stability. Further, the selective recovery at the certain r could also be available to similar technologies for recovering other kinds of substances.