Coupling of Anodic Oxidation and Soil Remediation Processes: A Review

Abstract

In recent years, due to industrial modernization and agricultural mechanization, several environmental consequences have been observed, which make sustainable development difficult. Soil, as an important component of ecosystem and a key resource for the survival of human and animals, has been under constant contamination from different human activities. Contaminated soils and sites require remediation not only because of the hazardous threat it possess to the environment but also due to the shortage of fresh land for both agriculture and urbanization. Combined or coupled remediation technologies are one of the efficient processes for the treatment of contaminated soils. In these technologies, two or more soil remediation techniques are applied simultaneously or sequentially, in which one technique complements the other, making the treatment very efficient. Coupling anodic oxidation (AO) and soil remediation for the treatment of soil contaminated with organics has been studied via two configurations: (i) soil remediation, ex situ AO, where AO is used as a post-treatment stage for the treatment of effluents from soil remediation process and (ii) soil remediation, in situ AO, where both processes are applied simultaneously. The former is the most widely investigated configuration of the combined processes, while the latter is less common due to the greater diffusion dependency of AO as an electrode process. In this review, the concept of soil washing (SW)/soil flushing (SF) and electrokinetic as soil remediation techniques are briefly explained followed by a discussion of different configurations of combined AO and soil remediation.

Towards Use of Persulfate Electrogenerated at Boron Doped Diamond Electrodes as Ex-Situ Oxidation Approach: Storage and Service-Life Solution Parameters

“…3 From an environmental point of view, a wide range of organic pollutants of different nature have been studied by using BDD-SO 4 2− /SO 4 •− /S 2 O 8 2− systems, such as pharmaceuticals, pesticides, herbicides, dyes, petroleum hydrocarbons, industrial chemicals and so on, considering synthetic and real effluents 1,2 as well as to treat effluents generated during the treatment of soil matrices (by using soil washing, electrokinetic soil remediation or soil flushing). 14,15 Also, similar approaches have been investigated as alternatives for microorganism's inactivation by electrodisinfection or food control applications 12 Note that when BDD-SO 4 12 Although • OH is a very reactive oxidizer, it has an important limitation, a very short half-life; 6 so, it is necessary that the species to be oxidized are very close to the electrode surface (Nernst layer). Meanwhile, it is well-known that persulfate has a half-life greater than that of the • OH, 10,16 and its stability favors solution diffusion.…”

“…Conversely, lower concentration removals were achieved, 33.28%, 35.04% and 36.20% for MO, 1,4-BQ and CF, respectively, when fresh-persulfate solution was used as an ex situ oxidation process. 1,15,35 On the other hand, the effectiveness of cold-persulfate solution electrochemically produced at 60 mA cm −2 , which was stored at 10 °C for 7 days, was tested in the degradation of all organic target compounds. Although, the oxidation power of cold-persulfate solution decreased significantly, the concentration removals for MO, 1,4-BQ and CF were more substantial than those achieved with fresh-persulfate solution (see, Fig.…”

Bibliometric Analysis of Global Research Progress on Electrochemical Degradation of Organic Pollutants

“…Ti is a material commonly used as a substrate for the electrodeposition of metallic elements and metallic oxides due to its high chemical stability, high mechanical strength, wide electrochemical potential windows and low cost (Ansari et Among the strategies used to improve electrocatalytic performance is the introduction of doping elements. In the case of PbO 2 and SnO 2 electrodes, doping with F, Bi, Fe, Ni, Co, Sb, Al, Pd, Yb, Ce, La, Gd, among other elements (Ferreira et al 2020;Yao et al 2020), managed to further improve the performance for electrochemical degradation of organic pollutants. For example, the addition of nickel metal to the Ti/SnO 2 -Sb-Ni electrode generated a more compact and uniform surface compared to the Ti/SnO 2 -Sb electrode, in addition to improving the oxidation performance for mineralization of the chloramphenicol compound (Li et al 2021).…”

Remediation Effect of Biomass Amendment on the Physical-Chemical Performance and Sustainable Utilization of Sandy Soil

“…In recent years, biomass amendment provides a new solution for soil remediation, with features like rich carbon, fine particle size, and high porosity. Nature hails "biomass improvement and its application" as one of the world's top 15 environmental issues [1][2][3][4]. Chinese and foreign scholars have explored extensively into the porosity, saturated water content, cation exchange capacity, and organic matter ratio of soil after the addition of biomass amendment, and further investigated the action mechanism of biomass amendment on farmland soil with microbial diversity, an indicator of the status of the soil ecosystem [5][6][7][8].…”