Mass Discharge Research Articles

Per- and Polyfluoroalkyl Substances in Water (2008-2022) and Fish (2015-2022) in The Netherlands: Spatiotemporal Trends, Fingerprints, Mass Discharges, Sources, and Bioaccumulation Factors.

Per- and polyfluoroalkyl substances (PFAS) are persistent, bioaccumulative, and toxic synthetic chemicals of concern, which have been detected in nearly all environmental compartments. The present study provides a data analysis on PFAS concentrations in the Dutch inland and coastal national waters and fish sampled from 2008 to 2022 and 2015 to 2022, respectively. Although the fish database is relatively small, the water database is unique because of its temporal dimension. It appears that PFAS are omnipresent in Dutch water and fish, with relatively small spatial differences in absolute and relative concentrations (fingerprints) and few obvious temporal trends. Only perfluorooctanoic acid and perfluorooctanesulfonic acid (PFOS) aqueous concentrations in the rivers Rhine and Scheldt have substantially decreased since 2012. Still, PFOS concentrations exceed the European water quality standards at all and fish standards at many locations. Masses of PFAS entering the country and the North Sea are roughly 3.5 tonnes/year. Generally, the data suggest that most PFAS enter the Dutch aquatic environment predominantly through diffuse sources, yet several major point sources of specific PFAS were identified using fingerprints and monthly concentration profiles as identification tools. Finally, combining concentrations in fish and water, 265 bioaccumulation factors were derived, showing no statistically significant differences between freshwater and marine fish. Overall, the analysis provides new insights into PFAS bioaccumulation and spatiotemporal trends, mass discharges, and sources in The Netherlands. Environ Toxicol Chem 2024;43:965-975. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Prediction of performance parameters of a hermetic reciprocating compressor applying an artificial neural network

The efficiency of the compressor's thermodynamic, mechanical, and electric motors can be increased by minimizing their losses. Based on the design characteristics of the compressor, the current study proposes an artificial neural network (ANN) model to forecast the mass flow rate, cooling capacity, compression power, and discharge line loss of the hermetic reciprocating compressor as outputs. This study uses experimental and numerical results obtained by the fluid–structure interaction (FSI) method, and the whole findings are used as inputs for the machine learning method. Using 36 numerical and 3 experimental data sets, a multilayer network is created with input parameters defining mass flow rate, cooling capacity, compression power, and discharge line energy loss. The input parameters for the network model are the compressor's design parameters, which include the compressor speed, discharge valve thickness, and discharge valve length. When comparing the experimental and FSI methods for compressor speeds of 1300, 2100, and 3000 rpm, the FSI study's mass flow rate and cooling capacity parameters converged at 11.9%, 9.1%, and 9.3%, respectively, to their actual values. The convergence rate to experimental compression power data was −0.3%, 2.6%, and 11%. The numerical-experimental deviation for discharge line energy losses is 14.9%, −3.6%, and 7.8%, respectively, for 1300, 2100, and 3000 rpm. With the Levenberg–Marquardt (LM) ANN model, which is used in this study, the average squared error value is calculated as 1.75E-02 and the R2 value is calculated as 0.99976. ANN model can predict outputs with average deviation rates of less than 0.88%. It is seen that results obtained with the ANN method provide high convergence on the experimental and FSI results, while the results obtained with the regression model deviate from the compressor exhaust line results by more than ±20%, and the ANN method is more successful than regression.

An empirical relation between velocity, mass discharge rate and vent area for normal through paroxysmal eruptions at Stromboli

An empirical relation between velocity, mass discharge rate and vent area for normal through paroxysmal eruptions at Stromboli

Discharge rate influenced by friction and shape of dimers: Numerical study

An influence of the particle aspect ratio in a range from 1 to 1.6 and the coefficients of particle – particle and particle – wall friction of dimer-shaped particles discharging from a flat-bottomed, cylindrical container on the mass discharge rate (MDR) was investigated using a discrete element method. The impact of the friction coefficients on the MDR was found to be stronger when compared to the effect of elongation. The most significant changes in MDR, influenced by friction, were observed for µpp < 0.2. For spherical particles with µpp < 0.4, the orifice diameter producing uncertain flow spread out from 4.2 to 4.7 particle diameters. No flow fluctuations were observed as coefficient of friction decreased below 0.2.

Preparation of Alumina Thin Films by Reactive Modulated Pulsed Power Magnetron Sputtering with Millisecond Pulses

This paper aims to investigate the quality of thin alumina films deposited on glass samples using magnetron sputtering in the reactive modulated pulsed power mode (MPPMS) and evaluate the process productivity. The aluminum target was sputtered in Ar/O2 gas mixtures with different fractions of oxygen in the total gas flow, in the fixed pulsed voltage mode. The pulse-on duration was varied between 5 and 10 ms, while the pulse-off time was 100 or 200 ms. The dependences of mass deposition rate and discharge current on the oxygen flow were measured, and the specific deposition rate values were calculated. Prepared coatings had a thicknesses of 100–400 nm. Their quality was assessed by scratch testing and by measuring density, refractory index, and extinction coefficient for different power management strategies. The strong influence of pulse parameters on the coating properties was observed, resulting in a maximum density of 3.6 g/cm3 and a refractive index of 1.68 for deposition modes with higher duty cycle values. Therefore, adjusting the pulse-on and pulse-off periods in MPPMS can be used not only to optimize the deposition rate but also as a tool to tune the optical characteristics of the films. The performance of the studied deposition method was evaluated by comparing the specific growth rates of alumina coatings with the relevant data for other magnetron discharge modes. In MPPMS, a specific deposition rate of 200 nm/min/kW was obtained for highly transparent Al2O3, without using any dedicated feedback loop system for oxygen pressure stabilization, which makes MPPMS superior to short-pulse high-power impulse magnetron sputtering (HiPIMS) modes.

A comparative analysis of a new semi-empirical model and the AHRI polynomial model for positive displacement compressors

A semi-empirical model has been proposed to predict the refrigerant mass flow rate, input power, and discharge temperature of positive displacement compressors. The prediction accuracy of the proposed model is compared with the accuracy of the AHRI polynomial model. To examine the generalizability of the models, a resampling methodology is used to compare prediction accuracy that results when smaller data sets are used to fit the models. These results show that the semi-empirical model has similar mass flow rate and input power prediction errors to the AHRI polynomial model and results in more consistent performance when smaller data sets are used to fit the model. The results also show that the AHRI polynomial is not a good choice for the prediction of discharge temperature and that the proposed model is much more suitable for this purpose.

Quantification of contaminant mass discharge from point sources in aquitard/aquifer systems based on vertical concentration profiles and 3D modeling

Point sources with contaminants, such as chlorinated solvents, per- and polyfluoroalkyl substances (PFAS), or pesticides, are often located in low-permeability aquitards, where they can act as long-term sources and threaten underlying groundwater resources. We demonstrate the use of a 3D numerical model integrating comprehensive hydrogeological and contamination data to determine the contaminant mass discharge (CMD) from an aquitard into the underlying aquifer. A mature point source with a dissolved chlorinated solvent in a clayey till is used as an example. The quantitative determination is facilitated by model calibration to high-resolution vertical concentration profiles obtained by direct-push sampling techniques in the aquifer downgradient of the contaminant source zone. The concentration profiles showed a plume sinking with distance from the source characteristic for such aquitard/aquifer settings. The sinking is caused by the interplay between infiltrating water and horizontal groundwater flow. The application of 3D solute transport modeling on high-resolution profiles allowed for determining the infiltration rate, the hydraulic conductivity in the aquitard, and, ultimately, the CMD. Different source zone conceptualizations demonstrate the potential effects of fractures and sorption in source zones in aquitards on CMD development. Fractures in the aquitard had a minor influence on the current CMD determined with the presented approach. Still, fractures with hydraulic apertures larger than 10 μm were crucial for the temporal development of the CMD and plume. A thorough characterization of the source zone conditions combined with high-resolution concentration profiles and detailed modeling is valuable for shedding light on the probable future development of groundwater contamination arising from sources in aquitard/aquifer settings and evaluating remedial actions.

Precise control of discharge of spherical particles by cone valve configuration: Insert – Converging orifice

The effect of the size and shape of the insert (inverted cone, sphere) when placed axially above an orifice on the mass discharge rate (MDR) of monodisperse spherical particles from a cylindrical silo has been investigated through experiments and DEM simulations. MDR characteristics have been measured for various distances between the insert and the orifice.An important practical finding is that, within a specific range of placement distances, the MDR increases by approximately 10% when a conical insert is used, whereas no such effect was observed when a spherical insert was employed.It was observed that, in some cases, a slight increase in friction coefficient leads to an increase in MDR as result of alterations in the initial grain structure, facilitating faster discharge.In a quasi-2D configuration, significant changes in flow rate occur when the thickness exceeds the natural multiple of dp, allowing the next layer of particles to flow.

Vibration and stability analyses of rotor–bearing-casing system in an axial piston pump subjected to bearing faults

Healthy roller bearings are essential for the safe performance of axial piston pumps. A dynamic failure model of a rotor–bearing-casing system was developed to investigate the effect of bearing damage on the vibration characteristics and stability. This model considers the effect of large-gap circulation on a wet rotor system model, which is closely related to the stirring conditions during actual operation of axial piston pumps. The stator and rotor of the pump were modelled using the centralised parameter technique and finite element method, which were combined to develop the rotor–bearing-casing model. Vibration and stability analyses were performed for the system model with bearing failure, considering the gap annular flow and hydraulic excitation force. The effects of the mass eccentricity, rotational speed, and discharge pressure on the vibration characteristics and stability were analysed under different types of bearing failures. Furthermore, the vibration behaviour of the rotor–bearing-casing system with a bearing fault was measured to validate the established dynamic model. The results indicated that the rotational speed and rotor eccentricity affected the churning and unbalanced effects of the rotor. With an increase in the rotor eccentricity, the rotor first transitioned from nonlinear motion to one-period motion and subsequently to periodic motion. The rotor energy reduction and steady state of the rotor–bearing-casing system were induced by the rotor churning action. As the annular gap decreased, churning losses increased, resulting in a more stable rotor motion.

Large encapsulated papillary carcinoma presenting as an arteriovenous malformation

Encapsulated papillary carcinomas (EPCs) are a rare breast tumour that carry a good prognosis. They are typically 0.5-8.0 cm in size and commonly present with a painless mass and bloody nipple discharge. We present an 80-year-old female with a 15.0 cm EPC, the largest reported in literature, that presented with an expanding breast haematoma and a distant history of breast trauma. Anaemic symptoms post initial aspiration, previous arterial injury to the same breast and prominent feeding vessels to the mass seen on both imaging, and at time of mastectomy, raise the differential of underlying vascular malformation.

Predicting the impact and duration of persistent and mobile organic compounds in groundwater systems using a contaminant mass discharge approach

This study investigated methods for predicting the duration and impact on groundwater quality from persistent and mobile organic compounds (PMOCs) at a drinking water well field affected by multiple contaminant sources. The fungicide metabolite N,N-dimethylsulfamide (DMS), which frequently occurs above the Danish groundwater quality criterion (0.1 μg/L), was used as an example. By combining contaminant mass discharge (CMD) estimations, modeling, and groundwater dating, a number of important discoveries were made. The current center of contaminant mass was located near the source area. The CMD at the well field was predicted to peak in 2040, and an effect from the investigated sources on groundwater quality could be expected until the end of the 21st century. A discrepancy in the current CMD at the well field and the estimated arrival time from the studied source area suggested an additional pesticide source, which has not yet been thoroughly investigated. The presence of the unknown source was supported by model simulations, producing an improved mass balance after inclusion of a contaminant source closer to the well field.The approach applied here was capable of predicting the duration and impact of DMS contamination at a well field at catchment scale. It furthermore shows potential for identification and quantification of the contribution from individual sources, and is also applicable for other PMOCs. Predicting the duration of the release and impact of contaminant sources on abstraction wells is highly valuable for water resources management and authorities responsible for contaminant risk assessment, remediation, and long-term planning at water utilities.

Effects of in-nozzle liquid fuel vortex cavitation on characteristics of flow and spray: Numerical research

The current work studies the dynamics of vortex cavitation under various conditions, including the pressure and orifice number, and their effects on the nozzle flow and spray characteristics using a modified cavitation model considering the swirling flow. Its validation against experimental data has demonstrated a high precision of the code in terms of vortex cavitation inside the nozzles. The higher the inlet pressure, the higher the mass flow rate and discharge coefficient, but the weaker the vortex cavitation; while the vortex cavitation intensity decreases, the discharge coefficient increases and the mass flow rate is almost constant with increasing back pressure. Moreover, under the influence of vortex cavitation, the primary jet liquid spreading angle, spray penetration, and spray volume coefficient increase first and then decrease with increasing inlet pressure; with an increase of back pressure, however, the primary jet liquid spreading angle increases, the spray penetration vice versa. Additionally, once the inner well-organized large-scale longitudinal vortices are destroyed, the vortex cavitation will not incept, which induces a larger discharge coefficient and spray penetration, but a smaller primary jet liquid spreading angle as a result. The swirling flow in the multi-hole nozzle is inhibited; hence, vortex cavitation is difficult.

Facile synthesis of pomegranate-like structured SiOx composite spheres with internal carbon conductive network for lithium-ion batteries

Incorporating carbon into unique structural particles is an effective way to further enhance cycle stability, the number of lithium-ion transfer channels within particles, and diffusion rate, but the procedure is intricate and challenging. The introduction of carbon into pomegranate-like SiO2 nanospheres is achieved by co-depositing SiO2 with carbon precursors to produce ultra-fine SiO2/C composite nanoparticles that replace the SiO2 nanoparticles that make-up the pomegranate spheres. The ultrafine SiO2/C composite nanoparticles encapsulated inside the sphere are connected to each other, creating a carbon-conductive network within the sphere. A mechanically stable outer carbon layer containing nitrogen is coated on the surface to form the (P-SiOx/CN)@CN composite material. The mechanically stable outer carbon layer, the reserved void space within the sphere, the core constructed by interconnected nanoparticles, and the carbon conductive network inside the sphere work together to endow the composite with superior electrochemical properties. The (P-SiOx/CN)@CN composite delivers high reversible mass discharge specific capacity of 970 mA h g−1 at 1.0 A g−1 over 500 cycles. This work develops a new approach to the facile synthesis of high-performance SiO2 anode materials for lithium-ion batteries.

Assessing Contaminant Mass Discharge Uncertainty With Application of Hydraulic Conductivities Derived From Geoelectrical Cross‐Borehole Induced Polarization and Other Methods

AbstractA new methodology was developed to support contaminant mass discharge (CMD)‐based risk assessment of groundwater contamination downgradient of point source zones. Geoelectrical cross‐borehole induced polarization (IP) data were collected at a site undergoing in situ remediation of chlorinated solvents for determining 2D hydraulic conductivity (K) distributions with an inversion model resolution of 0.15 m (vertically) x 0.50 m (horizontally) in three control planes from 10 to 20 m depth. Additionally, 18 slug tests and 31 grain size distribution analyses (GSA) from the control planes, were used for K‐estimation. The geometric means and variance of the IP, slug test, and GSA derived K‐estimates were consistent with previously studied sandy aquifers. Furthermore, the vertical variation in K between two geological settings, a sandy till and a meltwater sand formation, was clearly identified by the IP K‐estimates. The vertical variation was backed up by hydraulic profiling tool (HPT) measurements. Random realizations of CMD were simulated based on the cross‐borehole IP derived K‐values. For comparison, the CMD was also estimated with a geostatistical conditional simulation approach, using the data from slug tests and GSAs. The high IP resolution captured the small scale variations in K across the transects and led to CMD predictions with a narrow uncertainty interval, whereas slug test and GSA either under‐ or overestimated the magnitude of the areas with the highest CMD. Applying the geophysical cross‐borehole method for estimating K‐distributions in addition to traditional methods would improve CMD‐based risk assessment and evaluation of remediation performance at contaminated sites.

Detailed Comparison of Xenon APPI (9.6/8.4 eV), Krypton APPI (10.6/10.0 eV), APCI, and APLI (266 nm) for Gas Chromatography High Resolution Mass Spectrometry of Standards and Complex Mixtures.

Photoionization schemes for mass spectrometry, either by laser or discharge lamps, have been widely examined and deployed. In this work, the ionization characteristics of a xenon discharge lamp (Xe-APPI, 9.6/8.4 eV) have been studied and compared to established ionization schemes, such as atmospheric pressure chemical ionization, atmospheric pressure photoionization with a krypton discharge lamp (Kr-APPI, 10.6/10 eV) and atmospheric pressure laser ionization (266 nm). Addressing the gas-phase ionization behavior has been realized by gas chromatography coupled to high-resolution mass spectrometry without the usage of a dopant. For standard substances, it has been found that Xe-APPI is able to ionize a broad range of polycyclic aromatic hydrocarbons as well as their heteroatom-containing and alkylated derivatives. However, thiol and ester compounds could not be detected. Moreover, Xe-APPI revealed a high tendency to generate oxygenated artifacts, most likely due to a VUV absorption band of oxygen at 148 nm. Beneficially, almost no chemical background, commonly caused by APCI or Kr-APPI due to column blood, plasticizers or impurities, is observed. This advantage is noteworthy for evolved gas analysis without preseparation or for chromatographic coelution. For the complex mixtures, Xe-APPI revealed the predominant generation of radical cations via direct photoionization with a high selectivity toward aromatic core structures with low alkylation. Interestingly, both Xe-APPI and Kr-APPI could sensitively detect sterane cycloalkanes, validated by gas chromatographic retention. The narrowly ionized chemical space could let Xe-APPI find niche applications, e.g., for strongly contaminated samples to reduce the background.

Pump-and-treat (P&T) vs groundwater circulation wells (GCW): Which approach delivers more sustainable and effective groundwater remediation?

Pump-and-treat (P&T) is commonly used to remediate contaminated groundwater sites. The scientific community is currently engaged in a debate regarding the long-term effectiveness and sustainability of P&T for groundwater remediation. This work aims to provide a quantitative comparative analysis of the performance of an alternative system to traditional P&T, to support the development of sustainable groundwater remediation plans. Two industrial sites with unique geological frameworks and contamination with dense non-aqueous phase liquid (DNAPL) and arsenic (As) respectively, were selected for the study. At both locations, attempts were made for decades to clean up groundwater contamination by pump-and-treat. In response to persistently high levels of pollutants, groundwater circulation wells (GCWs) were installed to explore the possibility of accelerating the remediation process in unconsolidated and rock deposits. This comparative evaluation focuses on the different mobilization patterns observed, resulting variations in contaminant concentration, mass discharge, and volume of extracted groundwater. To facilitate the fusion of multi-source data, including geological, hydrological, hydraulic, and chemical information, and enable the continuous extraction of time-sensitive information, a geodatabase-supported conceptual site model (CSM) is utilized as a dynamic and interactive interface. This approach is used to assess the performance of GCW and P&T at the investigated sites. At Site 1, the GCW stimulated microbiological reductive dichlorination and mobilized significantly higher 1,2-DCE concentrations than P&T, despite recirculating a smaller volume of groundwater. At Site 2, As removal rate by GCW resulted generally higher than pumping wells. One conventional well mobilized higher masses of As in the early stages of P&T. This reflected the P&T's impact on accessible contaminant pools in early operational periods. P&T withdrew a significantly larger volume of groundwater than the GCW. The outcomes unveil the diverse contaminant removal behavior characterizing two distinct remediation strategies in different geological environments, revealing the dynamics and decontamination mechanisms that feature GCWs and P&T and emphasizing the limitations of traditional groundwater extraction systems in targeting aged pollution sources. GCWs have been shown to reduce remediation time, increase mass removal, and minimize the significant water consumption associated with P&T. These benefits pave the way for more sustainable groundwater remediation approaches in various hydrogeochemical scenarios.

Multizone Aquatic Ecological Exposures to Landfill Contaminants from a Groundwater Plume Discharging to a Pond.

While it is recognized that groundwater contaminant plumes can impact surface waters, there remains little information on the magnitude, spatial extent, and especially temporal variability of the resulting exposure to the variety of aquatic organisms, particularly for stagnant surface waters (e.g., ponds). The present study of a historic landfill plume discharging to a pond investigated contaminant exposure to multiple aquatic zones (endobenthic, epibenthic, pelagic) over approximately 1 year within a temperate climate. Landfill tracers included the artificial sweetener saccharin, ammonium, chloride, and specific conductance. Sampling of pond sediment porewater (upwelling groundwater) and continuous geophysical imaging of the subsurface showed a relatively stable plume footprint covering approximately 26% of the pond, although with spatially varying leachate composition, revealing year-round exposure to endobenthic (within sediments) organisms. Substantial and variable contaminant exposure to epibenthic organisms within the plume footprint was shown by elevated specific conductance measured directly above the sediment interface. Exposure varied daily at times and increased through winter to values representing undiluted plume groundwater. Exposure to pelagic organisms (overlying water) covered a larger area (~50%) due to in-pond circulation. The stream outlet concentrations were stable at approximately 10 times dilution for chloride and saccharin, but were substantially less in summer for ammonium due to in-pond processes. Whereas groundwater contaminants are typically assumed elevated at base flows, the outlet stream contaminant mass discharges to downstream receptors were notably higher in winter than summer, following stream flow patterns. Insights from the present study into the timings and locations of contaminant plume exposure to multiple ecological zones of a pond can provide guidance to contaminated site and aquatic ecosystem managers on improved monitoring, assessment, and remediation protocols. Environ Toxicol Chem 2023;42:1667-1684. © 2023 His Majesty the King in Right of Canada and The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. Reproduced with the permission of the Minister of Environment and Climate Change Canada.

Determining groundwater recharge for quantifying PFAS mass discharge from unsaturated source zones

AbstractSoil‐to‐groundwater contaminant mass discharge (Md) is the authoritative metric defining source strength at sites impacted by per‐ and polyfluoroalkyl substances (PFAS) and is increasingly being reported. Accurate estimates of groundwater recharge at representative spatial scales, however, is critical to quantitatively estimating Md, which to date has received comparatively little attention relative to PFAS‐specific partitioning and retention processes within unsaturated zone source areas despite a plethora of available literature. The objective of this review is to summarize the concept of Md as it applies to PFAS‐impacted sites, present standardized terminology, and collate published literature on groundwater recharge for a practitioner‐level summary of practical methods. Critically, the primary aim is to reduce uncertainty in recharge (and, thus, Md) estimates commensurate to a given site management application (i.e., the data quality objective process). Therefore, we propose a tiered system of increasing cost, complexity, and certainty depending on specific project requirements and site conditions and recommend applicable recharge methods for each tier based on these factors. Ultimately, a framework is presented for the assessment of PFAS‐impacted source areas based on the concept of Md.

Modeling of Complex, Multi‐Component NAPL Remediation for Decision Support

AbstractIn situ remediation of nonaqueous phase liquid (NAPL)‐impacted sites is difficult and costly. Even with enhancements (e.g., chemical and thermal) and partial NAPL recovery, mass transfer constraints associated with partitioning from residual NAPL typically control the depletion rate of sources and attainment of cleanup goals. Practical methodologies are needed to support strategic evaluation, planning, and implementation of cost‐effective remedial approaches that are considered protective. A modeling system averaging over the NAPL‐impacted saturated soil volume was developed and demonstrated at the former Williams Air Force Base. The system combines upscaled, physically based mass transfer coefficients for multi‐component NAPL dissolution with theoretical enhancements specific to multiple remediation processes. Dissolution increases in the presence of aqueous phase reactions, according to first‐ or second‐order kinetics, by increasing concentration gradients. Slow biological processes are considered first order in modeling natural attenuation and enhanced biological degradation. Fast reactions associated with chemical oxidation are considered second order. These enhancement models are equally applicable to numerical simulations of NAPL remediation. Pump and treat enhances dissolution in proportion to increases in the characteristic velocity associated with dissolution. The demonstration yielded realistic predictions, with greater certainty, for outcomes from of multiple technologies intended to reduce remedial timeframes and life cycle costs. The enhanced dissolution modeling provides a site‐specific, quantitative assessment of changes in NAPL source discharge concentration and mass discharge over time for various remedial options that is equivalent to assessments from complex numerical transport models, given typical input data limitations.

Numerical Modeling and Data‐Worth Analysis for Characterizing the Architecture and Dissolution Rates of a Multicomponent DNAPL Source

AbstractA numerical solute transport model was calibrated to a high‐resolution monitoring data set to characterize a multicomponent source of nonaqueous phase liquids (NAPLs) and evaluate the uncertainty of estimated parameters. The dissolution of NAPL mass was simulated using SEAM3D with parameter zones including adjustable NAPL saturations and mass transfer coefficients, representing the heterogenous architecture of the source zone. Source zone parameters were simultaneously estimated using PEST from aqueous‐phase concentrations measured in a multilevel monitoring transect and from mass recovery rates measured at extraction wells during a controlled field experiment. Data‐worth analyses, facilitated by PEST ancillary software, linked maximum aqueous‐phase concentrations of all compounds to reductions in the pre‐calibration uncertainty of mass transfer coefficients. In turn, decreasing concentrations of the most soluble NAPL fraction constrained the source mass estimation. The accurate estimation of model parameters was possible by removing concentrations measured during early NAPL dissolution stages, identified as drivers of model bias using the iterative ensemble smoother PESTPP‐iES. Although uncertainty analyses highlighted model limitations for representing sub‐grid‐scale heterogeneity of NAPL distribution and mass transfer rates, final stages of NAPL dissolution measured at multilevel ports eliminated parameter bias and produced long‐term projections of multi‐stage source zone depletion. Including mass discharge rates for model calibration further improved the accuracy of estimated residual source mass, complementing multilevel monitoring constraints on the saturation distribution and mass transfer coefficients.