Trace Organic Contaminant Transfer and Transformation in Bioretention Cells: A Field Tracer Test with Benzotriazole

Abstract

Bioretention cells can effectively infiltrate stormwater runoff and partly remove conventional water contaminants. A field tracer injection experiment in a conventionally designed bioretention cell was used to investigate the fate of benzotriazole, a model trace organic contaminant, during and between runoff events. Moderate (29%) benzotriazole load reductions were measured during the 6 h long injection experiment. The detection of 1-methyl benzotriazole, hydroxy benzotriazole, and methoxy benzotriazole provided in situ evidence of some rapid benzotriazole microbial transformation during the tracer test and more importantly between the events. The detection of benzotriazole alanine and benzotriazole acetyl alanine also showed fast benzotriazole phytotransformation to amino acid conjugates during the tracer test and suggests further transformation of phytotransformation products between events. These data provide conclusive full-scale evidence of benzotriazole microbial and phytotransformation in bioretention cells. Non-target chemical analysis revealed the presence of a diverse range of trace organic contaminants in urban runoff and exiting the bioretention cell, including pesticides and industrial, household, and pharmaceutical compounds. We have demonstrated the in situ potential of urban green infrastructure such as bioretention cells to eliminate polar trace organic contaminants from stormwater. However, targeted design and operation strategies, for example, hydraulic control and the use of soil amendments, should be incorporated for improved bioretention cell performance for such compounds.

The regenerative role of biofilm in the removal of pesticides from stormwater in biochar-amended biofilters

“…Effluent samples (1 mL) were taken every 20 min, diluted with Milli-Q water and analyzed by ion chromatography (IC). Based on the salt tracer data, mean HRTs of the columns were between 90-125 min (consistent with a recent bioretention study 56 ), with the variance likely due to experimental variation rather than the presence of biochar or a biofilm (see Fig. S6 †).…”

Stormwater Bioretention Cells Are Not an Effective Treatment for Persistent and Mobile Organic Compounds (PMOCs)

“…The cell is unlined, allowing exfiltration through the sides and bottom to the surrounding native soil. A perforated pipe drains the unexfiltrated water to a nearby receiving body. , Gu et al used a two-compartment version of this model to model the fate of bromide, rhodamine-WT, and benzotriazole in the same bioretention cell considered here (see below) …”

“…The mobile water, soil, root body, xylem, and central cylinder compartments were also discretized to the finite volume grid. The final finite volume unit represented the drainage zone (gravel drain), where we assumed that no roots were present . Evapotranspiration into the root compartments (root body, xylem, and central cylinder) entered the soil compartment before flowing through the root central cylinder to the shoots.…”

“…Bioretention cell geometry data were obtained from Spraakman et al . We assumed that the poor utilization of the bioretention area observed for the tracer experiment continued for the subsequent events. The system studied here contained porous soil leading to an extremely fast drawdown time, much faster than the ∼24 h recommended by local design guidance documents. , Many bioretention cells are designed like this one with a high (∼80–90%) proportion of sand in the bioretention soil …”

Promotion of Bladder Cancer Cell Metastasis by 2-Mercaptobenzothiazole via Its Activation of Aryl Hydrocarbon Receptor Transcription: Molecular Dynamics Simulations, Cell-Based Assays, and Machine Learning-Driven Prediction

“…Extensive exposure to MBT occurred through direct contact with consumer products and other environmental matrices. MBT residues have reached 30 μg/L in surface water, − 70 μg/L in sediments, 840 μg/L in wastewater, − and 591 pg/m 3 in airborne particulate matter . MBT was also detected in human bodies, including exhaled breath condensate (up to 6.7 μg/L), and concentrations in the urine of occupational groups were as high as 6210 μg/L (∼37.1 μM) .…”