A Review on Electrochemical Degradation and Biopolymer Adsorption Treatments for Toxic Compounds in Pharmaceutical Effluents

Abstract

Pharmaceutical industries generate very large quantities of toxic organic compounds which include volatile organic compounds (VOCs) and/or organic volatile impurities (OVIs). These toxic compounds, amongst which are emerging residual solvents, largely come from wastewater treatment plants (WWTPs) and are being continuously dumped into the environment at an alarming rate. Efficient treatment of pharmaceutical wastewaters (effluents) is currently a major challenge because of not only the enormous quantity to be disposed of but also its complexity, as well as its hazardous nature. Dumping these kinds of polluted wastes into the environment at uncontrolled rates are putting increasing pressure on freshwater ecosystems. This review paper focuses on combined electrochemical degradation and biopolymer adsorption treatment processes and techniques for toxic compounds in pharmaceutical wastewater treatment. These emerging processes such as the combination of electrochemical techniques as a primary treatment method, followed by an adsorption process, is now a topic of intense research as it is proving to very feasible, ecofriendly, and cost-effective in the complete recovery of toxic residual solvents from binary aquatic systems. This paper presents major toxic pollutants in pharmaceutical wastewaters and their fate in the aquatic environment, their sources, and origin in pharmaceutical industries. The evaluation of the traditional methods used for the removal of these emerging organic pollutants from aquatic matrices and pharmaceutical effluents is accomplished. New developments in electrochemical treatments for the remediation of toxic compounds in pharmaceutical wastewaters are also discussed.

Robust and Self‐Cleaning Electrochemical Production of Periodate

“…Mineralization of these impurities is not harming the oxidative recycling of periodate. As shown previously, the formation of periodate occurs via hydroxyl radicals, which can also degrade and mineralize the organic impurities [59–61] . In this study, 8 different organic dyes, 3 contrast media, and 8 different iodine compounds were tested as impurities and shown to degrade during periodate recycling, as verified by UV/Vis spectroscopy and mass spectrometry (MS).…”

“…As shown previously, the formation of periodate occurs via hydroxyl radicals, which can also degrade and mineralize the organic impurities. [59][60][61] In this study, 8 different organic dyes, 3 contrast media, and 8 different iodine compounds were tested as impurities and shown to degrade during periodate recycling, as verified by UV/Vis spectroscopy and mass spectrometry (MS). Iodo compounds (e.g., from industrial processes) could even enhance the periodate yield by upcycling.…”

Molecular inspired electrocatalyst materials for environmental remediation

“…98 Microbiological and enzymatic degradation processes are time-consuming, expensive, and have low conversion yields. 20,99 Electrochemical dehalogenation 12,95,100 requires heterogenous electrodes typically made of expensive Ag and Pd (since they can easily adsorb hydrogen) to catalyze the X/H exchange, 101,102 and their surface can easily be passivated during the initial electrolysis steps. 103 Molecular inspired electrocatalysts can be efficient and affordable options for dehalogenation of HOCs, and Table 1 shows some representative examples and their corresponding metrics and parameters.…”

“…10,11 Electrochemical methods can be cheap, easy to implement, provide high removal efficiencies, and have the capability to be powered by renewable electricity, making them environmentally friendly and scalable. [12][13][14] Most electrochemical processes use anodes and cathodes made of metals, alloys, metallic nanoparticles, metallic foams, metal-carbon scaffolds, and, more recently, boron-doped diamond (BDD), 15 to oxidize or reduce pollutants in water. 16 These materials can promote C-H bond activation, 17 C-C bond homolytic cleavage, 18 decarboxylation reactions, 19 dehalogenation reac-tions, 20 and other small molecule activation.…”

The Experimental Design Approach to Removal of Endocrine Disrupting Compounds from Domestic Wastewater by Electrooxidation Process

“…After adsorption to the anode surface of the compounds, direct anodic oxidation (through direct electron transfer to the anode) comprises electron exchange between the compounds and the anode surface without the presence of other substances [56,88]. Theoretically, such oxidation is conceivable at more negative potentials than are required for the hydrolysis and the creation of oxygen.…”