Study on a Real-Time Control Strategy to Cr(VI) Removal with Fluctuation of Influent in Fe-Electrocoagulation-Al-Electroflotation Reactor

Abstract

The overall goal of this study was to construct a real-time control strategy to Cr(VI) removal with fluctuation of influent using Fe-Electrocoagulation (EC)-Al-Electroflotation (EF) reactor. Firstly, we used the pH as the indirect indicators to developed mechanism models that could describe the process of Cr(VI) reduction to Cr(III). During the process of Fe-EC, if [pHm]/ t≤ [pHp]/ t, indicating that Cr(VI) was completely removed. Model M2 was more capable of predicting the terminal time of Fe-EC process than Model M1. To improve accurate of model M2, the effective rate of Fe(II) for Cr(VI) reduction (ϕ = 28.7%) in an extremely adverse conditions was defined, and the optimal t equation was deduced according to monitoring accuracy and stability of pH monitor. Subsequently, the response surface methodology (RSM) was used to develop flocculation-flotation empirical models of suspended particles of Cr(III). The model of response of the residual total Cr and turbidity, temperature, electric quantity per volume (Q) and settling time was constructed. Verification results show the efficiency of the proposed model. Finally, we constructed a real-time control strategy by combined the Fe-EC and Al-EF, which could save 58.8% of anode material and 58.3% of electricity power and reduce 58.7% of sludge production compared to traditional control process.

Clinoptilolite augmented electrocoagulation process for the reduction of high‐strength ammonia and color from stabilized landfill leachate

“…Further increment in both pollutants removals was observed after 35 min up to 70 ± 1% and 88 ± 1% for ammonia and color, respectively, with sustained rates till the end of the experiment. The high removal efficiencies of these pollutants can be attributed to the existence of coagulant species of polymeric Al hydroxide that concurrently enhanced the flocculation of small particles, leading to precipitate reaction (Onen et al, 2018; Xu et al, 2018). This result is fairly in agreement with numerous earlier works on single EC process as reported by Khorram and Fallah (2018), Onen et al (2018), and Xu et al (2018) who documented 30 min as the optimum settling duration.…”