Uptake and Detoxification of Organic Micropollutants by Macrophytes in Constructed Wetlands

Pollution by organic micropollutants (OMPs) is recognized worldwide as an emerging environmental problem. Since conventional wastewater treatment processes are generally ineffective for most of these pollutants, alternative/complementary technologies need to be considered with the aim of more efficiently addressing this problem. Constructed wetlands is a promising technology that uses plants and microorganisms to remove OMPs from wastewaters. As result of their sedentary nature, plants have evolved diverse abilities for dealing with toxic compounds present in their environment. They, therefore, possess a variety of pollutant attenuation mechanisms that makes their use in wastewater treatment more feasible than physical and chemical processes. This chapter presents an overview of OMPs’ fate inside plants, following their uptake, and discusses the main factors influencing their uptake and translocation within plants. The various phases of the metabolic transformations of organic pollutants inside plants, which have the aim of modifying the xenobiotics in order to make them less toxic to the plants, are also described in this chapter. Finally, a brief account is given on the response of antioxidant defense systems of plants which are triggered by abiotic stress conditions that may result from long-term exposure of plants to OMPs

The Role of Macrophytes in the Removal of Organic Micropollutants by Constructed Wetlands

The contamination of aquatic environments with organic micropollutants (OMPs) resulting from human activities is becoming a widespread, serious environmental issue. The problem is mainly rooted in a general inefficiency of conventional wastewater treatment plants to deal with this type of pollutants, which causes treated wastewaters to still contain significant amounts of OMPs as they are discharged into the receiving water bodies. Among various technologies that have been developed and evaluated for removal of OMPs from wastewaters, constructed wetland systems (CWS) are generally seen as a cost-effective option. Aquatic macrophytes are a fundamental component of CWS, possessing a vast potential for removal, transformation/degradation of a variety of OMPs. This chapter presents a review focusing on the role of macrophytes in CWS targeted for OMPs removal, detailing the several types of physical, chemical and biological processes that may be responsible for their role in removing these pollutants from wastewater, how these processes are affected by several conditions and characterizing the situations where each type of process may be more relevant. Furthermore, the types of interactions that potentially occur between plants and the other components of CWS, and how important these interactions may be for the system's performance are briefly presented

Bioelectrochemical enhancement of methane production from exhausted vine shoot fermentation broth by integration of MEC with anaerobic digestion

[ES] A microbial electrolysis cell integrated in an anaerobic digestion system (MEC-AD) is an efficient configuration to produce methane from an exhausted vine shoot fermentation broth (EVS). The cell worked in a single-chamber two-electrode configuration at an applied potential of 1 V with a feeding ratio of 30/70 (30% EVS to 70% synthetic medium). In addition, an identical cell operated in an open circuit was used as a control reactor. Experimental results showed similar behavior in terms of carbon removal (70–76%), while the specific averaged methane production from cycle 7 was more stable and higher in the connected cell (MECAD) compared with the unpolarized one (OCAD) accounting for 403.7 ± 33.6 L CH4·kg VS−1 and 121.3 ± 49.7 L CH4·kg VS−1, respectively. In addition, electrochemical impedance spectroscopy revealed that the electrical capacitance of the bioanode in MECAD was twice the capacitance shown by OCAD. The bacterial community in both cells was similar but a clear adaptation of Methanosarcina Archaea was exhibited in MECAD, which could explain the increased yields in CH4 production. In summary, the results reported here confirm the advantages of integrating MEC-AD for the treatment of real organic liquid waste instead of traditional AD treatment.SIPublicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCL

Destruction of chemical warfare surrogates using a portable atmospheric pressure plasma jet

Today’s reality is connected with mitigation of threats from the new chemical and biological warfare agents. A novel investigation of cold plasmas in contact with liquids presented in this paper demonstrated that the chemically reactive environment produced by atmospheric pressure plasma jet (APPJ) is potentially capable of rapid destruction of chemical warfare agents in a broad spectrum. The decontamination of three different chemical warfare agent surrogates dissolved in liquid is investigated by using an easily transportable APPJ. The jet is powered by a kHz signal source connected to a low-voltage DC source and with He as working gas. The detailed investigation of electrical properties is performed for various plasmas at different distances from the sample. The measurements of plasma properties in situ are supported by the optical spectrometry measurements, whereas the high performance liquid chromatography measurements before and after the treatment of aqueous solutions of Malathion, Fenitrothion and Dimethyl Methylphosphonate. These solutions are used to evaluate destruction and its efficiency for specific neural agent simulants. The particular removal rates are found to be from 56% up to 96% during 10 min treatment. The data obtained provide basis to evaluate APPJ’s efficiency at different operating conditions. The presented results are promising and could be improved with different operating conditions and optimization of the decontamination process

Decontamination of waterborne chemical pollutants by using atmospheric pressure nonthermal plasma: a review

<div><p>Water pollution abatement is a topic of growing interest worldwide, mainly due to the large number of contaminants that continental waters may contain and the need for a safe wastewater reclamation and reuse in many sectors (agriculture, industry, aquifer recharge, and landscape restoration) and industrial recycling to reduce the end-of-pipe treatment. In this review, different advanced oxidation processes based on atmospheric pressure nonthermal plasma treatment for the removal of organic contaminants from waters are critically reviewed. Factors affecting the removal efficiency and energy yield are reviewed for specific organic contaminants (e.g. VOC, phenols, organic dyes, pharmaceuticals and personal care products, surfactants) and also for conventional water quality parameters (e.g. BOD, COD, TOC, , turbidity). Moreover, effects of operational modes (e.g. type of discharge, reactor configuration, plasma gas), catalytic processes (heterogeneous: TiO₂, NiO, and homogeneous: Cu²⁺, Fe²⁺, ), post-treatment reactions and external oxidant addition (O₃, H₂O₂) are also presented.</p></div