Sorption and leaching of benzalkonium chlorides in agricultural soils

Choe

Environmental Engineering Research

et al. 2021

Because disinfectants have been essential during the COVID-19 pandemic, the global demand for benzalkonium chlorides (BACs) has significantly increased. BACs can inactivate coronaviruses, but are known as toxic. In this study, we investigated the adsorption mechanisms of BAC12, BAC14, and BAC16 in water using powdered activated carbon (PAC). The effects of the reaction time, pH, and temperature on the adsorption kinetics of BACs were examined. The adsorption reaction followed pseudo-second-order kinetics, and better fitted to the Langmuir isotherm than the Freundlich isotherm. The best adsorption of BACs was achieved at neutral pH conditions. Thermodynamic analysis revealed that adsorption of BACs onto PAC is a spontaneous and endothermic process. Competitive adsorption experiments revealed that BACs with longer alkyl chains were adsorbed more effectively onto PAC than shorter alkyl chain BACs, implying that, while the electrostatic interaction is an important adsorption mechanism for BAC12, van der Waals interaction plays a more important role during the adsorption of BAC14 and BAC16. Finally, we observed the partial detoxification (69%) BAC in adsorption treated water with PAC using a Microtox test.

Section: Adsorption Isothermscontrasting

confidence: 75%

Adsorption of benzalkonium chlorides onto powdered activated carbon: mechanisms and detoxification

Choe

Environmental Engineering Research

et al. 2021

“…The data obtained in this study suggested that ODTMA-Br (C18) might be a cyanocide candidate with a relatively longer duration in suppressing cyanobacterial blooms. Although several studies have reported the (eco)toxicity of QACs [39,40], these compounds are adsorbed into particulate matter rapidly after application [41,42], and the possibility to become bioavailable through leaching from the particulate fraction is very low at environmentally relevant concentrations [43]. Moreover, QACs are susceptible to microbial degradation [44].…”

Section: Impacts On the Long-term Biodiversitymentioning

confidence: 99%

Can Alkyl Quaternary Ammonium Cations Substitute H2O2 in Controlling Cyanobacterial Blooms—Laboratory and Mesocosm Studies

et al. 2021

Mitigation of harmful cyanobacterial blooms that constitute a serious threat to water quality, particularly in eutrophic water, such as in aquaculture, is essential. Thus, in this study, we tested the efficacy of selected cyanocides towards bloom control in laboratory and outdoor mesocosm experiments. Specifically, we focused on the applicability of a group of cationic disinfectants, alkyltrimethyl ammonium (ATMA) compounds and H2O2. The biocidal effect of four ATMA cations with different alkyl chain lengths was evaluated ex situ using Microcystis colonies collected from a fish pond. The most effective compound, octadecyl trimethyl ammonium (ODTMA), was further evaluated for its selectivity towards 24 cyanobacteria and eukaryotic algae species, including Cyanobacteria, Chlorophyta, Bacillariophyta, Euglenozoa and Cryptophyta. The results indicated selective inhibition of cyanobacteria by ODTMA-Br (C18) on both Chroccocales and Nostocales, but a minor effect on Chlorophytes and Bacillariophytes. The efficacy of ODTMA-Br (C18) (6.4 μM) in mitigating the Microcystis population was compared with that of a single low dose of H2O2 treatments (117.6 μM). ODTMA-Br (C18) suppressed the regrowth of Microcystis for a longer duration than did H2O2. The results suggested that ODTMA-Br (C18) may be used as an effective cyanocide and that it is worth further evaluating this group of cationic compounds as a treatment to mitigate cyanobacterial blooms in aquaculture.

“…The emitted amount ultimately accumulated in sludge and it was found that the total sum of BAC-12 and BAC-14 in the digested sludge of three different Swedish WWTPs was greater than 1000 kg/yr, highlighting potential concerns for the use of sludge for land application [257]. Furthermore, sorption kinetic studies of municipal sludge and lime-stabilized biosolids revealed that the sorption affinity of BACs is very high, while mobility in aqueous phase is very low [295,296]. The presence of the commonly encountered BAC-10, BAC-12, BAC-14 and BAC-16 in digested sludge provides evidence of the wide distribution of BAC homologues in sludge [261].…”

Section: Benzalkonium Chlorides In Sludge and Biosolidsmentioning

confidence: 99%

“…Biodegradation and abiotic transformations are not significant for BACs [270,298]. Therefore, physical separation by sorption is an important contributor to the fate and environmental distribution of BACs [291,295,296,303].…”

Section: Fate Transformation and Impacts Of Benzalkonium Chlorides Imentioning

confidence: 99%

A Review on the Fate of Legacy and Alternative Antimicrobials and Their Metabolites during Wastewater and Sludge Treatment

Abbott

Kor-Bicakci

Islam

et al. 2020

IJMS

Antimicrobial compounds are used in a broad range of personal care, consumer and healthcare products and are frequently encountered in modern life. The use of these compounds is being reexamined as their safety, effectiveness and necessity are increasingly being questioned by regulators and consumers alike. Wastewater often contains significant amounts of these chemicals, much of which ends up being released into the environment as existing wastewater and sludge treatment processes are simply not designed to treat many of these contaminants. Furthermore, many biotic and abiotic processes during wastewater treatment can generate significant quantities of potentially toxic and persistent antimicrobial metabolites and byproducts, many of which may be even more concerning than their parent antimicrobials. This review article explores the occurrence and fate of two of the most common legacy antimicrobials, triclosan and triclocarban, their metabolites/byproducts during wastewater and sludge treatment and their potential impacts on the environment. This article also explores the fate and transformation of emerging alternative antimicrobials and addresses some of the growing concerns regarding these compounds. This is becoming increasingly important as consumers and regulators alike shift away from legacy antimicrobials to alternative chemicals which may have similar environmental and human health concerns.