Low Trihalomethane Formation during Managed Aquifer Recharge with Chlorinated Desalinated Water

Abstract

Trihalomethanes (THMs) are toxic disinfection by-products, formed in the reaction of chlorine with organic matter. This work aimed to study THM formation during a unique case study of managed aquifer recharge (MAR) with chlorinated desalinated seawater. THM formation was tested in the field, along a 3.0 m deep vadose zone gallery. Two small-scale experiments were conducted in the site, with untreated and with bromide spiked desalinated seawater. These were accompanied by a large-scale, ~1-month long operational MAR event. In the small-scale experiments, THM concentrations were shown to increase with bromide concentrations, with increasing dominance of the brominated species. Nevertheless, concentrations remained within the single µg/L range, which is an order of magnitude lower than drinking water regulations. Such low THM concentrations were also determined in the large-scale event. In both cases, THM formation occurred in the ponding water, without significant formation or degradation in the upper 3.0 m of the vadose zone. This study shows that MAR with chlorinated (<0.5 mg/L) desalinated seawater through sandy infiltration basins does not pose a threat to drinking water quality at this site.

Modification of Disinfection Process at a Local Water Treatment Plant—Skawina (Poland)

“…The role of critical factors controlling the formation of DBPs has received a great deal of attention recently. Extensive research efforts have continued, including laboratory-scale testing, pilot plant testing, investigations carried out at water treatment works [28][29][30][31][32][33][34][35], and local reports [15,[36][37][38][39]. The mutagenicity of chlorinated water is higher than that of water treated with minimal doses of chlorine and ozone [40,41].…”

Simultaneous determination of stable chlorine and bromine isotopic ratios for bromochlorinated trihalomethanes using GC-qMS

“…For instance, the presence of THMs in the atmosphere is of environmental concern as these compounds play an important role on the ozone depletion in the stratosphere (Montzka et al, 1999;Shechner et al, 2019). Also, chlorination of drinking water, wastewater and seawater releases THMs as dissolved disinfection by-products (Chowdhury et al, 2010;Hu et al, 2019;Kim et al, 2015;Padhi et al, 2019), which can contaminate surface water, groundwater and drinking water and poses a serious threat to ecosystem and human health (Bernstein et al, 2020;Komaki et al, 2018). The latter may be particularly at risk through the intake of THMs upon consumption of drinking water treated by chlorination (Ashley et al, 2020).…”

Optimization of compound‐specific chlorine stable isotope analysis of chloroform using the Taguchi design of experiments

“…Chloroform (CHCl 3 ), a toxic chlorinated hydrocarbon, is detected at various concentrations in tap water, surface water reservoirs (natural and manmade), and some aquifers. In addition to the natural formation of chloroform, 1,2 chlorination of water supplies may result in the formation of trihalomethanes (THMs), as the chlorine reacts with organic matter, 3,4 with chloroform being one of the main products 5 . Moreover, its wide manufacture and use as an industrial solvent, and its commercial use contribute to its common occurrence and detection.…”