Outlet Samples Research Articles

Suspended sediment connectivity analysis: Snowmelt-driven dynamics in an alpine basin

Understanding snowmelt and its related suspended sediment transport in mountain streams is a crucial issue in the world of hydraulic and sediment research. Field-based approaches are still poorly used to investigate the response of mountain basins to different stages of snowmelt. To explain the suspended sediment dynamics of the Rio Cordon basin (Italy, Dolomites), the snowmelt in the year 2021 was analysed. First, a descriptive analysis of temporal trends of meteorological, hydrological, and sedimentological variables was carried out. Second, suspended sediment budgets of the main channel were quantified, considering the contribution of the tributaries at week- and event- scale, and supported by hysteresis analyses. Third, the role of sediment sources and snow cover was examined and integrated to comprehend variations in sediment supply from tributaries. Data were collected using a (i) multiparametric sonde installed at the outlet, (ii) water and sediment samples at significant points along the channel network, (iii) satellite images and sediment sources inventory. The whole snowmelt period 2021 featured 210.8 mm of precipitation and a mean temperature of 4.6°C. The total load of suspended sediment was 100 t. The main period of ablation was May, which showed contrasting suspended sediment dynamics in the four weeks. Sediment availability exceeded transport capacity in the initial two weeks, whereas transport capacity exceeded sediment availability in the subsequent two weeks. The main snowmelt event analysis mirrored the same trend: limited transport during the rising limb and the opposite during the falling limb. Such results were confirmed by the hysteresis analysis, proving to be an effective tool for detecting changes in suspended sediment connectivity. The variations of snow cover and the extent of sediment sources across the sub-basins influence the sediment supply. This study enhances our comprehension of snowmelt-driven hydrological and sedimentological dynamics, providing insights into the resilience of mountains to changing climate conditions.

From the highway to receiving water bodies: identification and simultaneous quantification of small microplastics (< 100µm) in highway stormwater runoff.

Highway stormwater (HSW) runoff is among the environment's most important sources of microplastics. This study aimed to characterize via vibrational spectroscopy and quantify SMPs (small microplastics < 100µm) in HSW runoff from a trafficked highway entering a facility equipped with a filtration system and in those flowing out to the receiving water body near agricultural activities. Samples of the inlet runoff (from the highway) and outlet runoff (the discharge into the environment) were collected in different periods to investigate potential seasonal and spatial differences. The sampling, methodology, and analysis were thoroughly carried out to quantify and simultaneously identify SMPs via Micro-FTIR to obtain a specific novel dataset to assess the environmental quality of highway pollution. A significant difference between inlet and outlet samples was reported; the highest abundance in inlet samples was 39813 ± 277 SMPs L.1 (SW10 IN; average length of 77µm), while the highest one in outlet samples was 15173 ± 171 SMPs L-1 (SW10 OUT; SMPs' average length of 63µm). Polyamide 6 (PA 6) and High-Density Polyethylene (HDPE) were predominant. Our results show that these HSW treatment plants, designed for managing regulated pollutants, can intercept SMPs, improving the quality of HSW runoff discharged into the environment.

Temporal and spatial changes in the abundance of antibiotic resistance gene markers in a wastewater treatment plant.

In this study, we investigated the temporal and spatial quantitative changes in the concentration of antibiotic resistance gene (ARG) markers in a municipal wastewater treatment plant (WWTP). Four ARGs conferring resistance to different classes of antibiotics (ermB, sul1, tet[W], and blaCTXM) and a gene used as a proxy for ARG pollution (intl1) were quantified in two separate sampling campaigns covering two and half years of operation of the WWTP. First, a systematic monthly monitoring of multiple points in the inlet and the outlet revealed an absolute decrease in the concentration of all analyzed ARGs. However, the relative abundance of sul1 and intl1 genes relative to the total bacterial load (estimated using the universal marker 16S rDNA) increased in the outlet samples as compared to the inlet. To pinpoint the exact stage of removal and/or enrichment within the WWTP, a second sampling including the stages of the biological treatment was performed bimonthly. This revealed a distinct enrichment of sul1 and intl1 genes during the biological treatment phase. Moreover, the temporal and spatial variations in ARG abundance patterns within the WWTP underscored the complexity of the dynamics associated with the removal of ARGs during wastewater treatment. Understanding these dynamics is pivotal for developing efficient strategies to mitigate the dissemination of ARGs in aquatic environments. PRACTITIONER POINTS: Regular monitoring of ARG markers in WWTPs is essential to assess temporal and spatial changes, aiding in the development of effective mitigation strategies. Understanding the dynamics of ARG abundance during biological treatment is crucial for optimizing processes and minimizing dissemination in aquatic environments. Increased relative abundance of certain ARGs highlights potential enrichment during wastewater treatment, necessitating targeted interventions. Systematic monitoring of multiple points within WWTPs can provide valuable insights into the efficacy of treatment processes in reducing ARG levels over time. The complexity of ARG abundance patterns underscores the need to develop holistic approaches to tackle antibiotic resistance in wastewater systems.

Bacterial microbiome dynamics in commercial integrated aquaculture systems growing Ulva in abalone effluent water

In South Africa, the green seaweed Ulva lacinulata is grown in land-based integrated multi-trophic aquaculture (IMTA) farms with the abalone Haliotis midae. The Ulva serves as a biofilter and the co-produced Ulva is often used as feed for the abalone. To better understand the potential benefits and risks associated with this practice, this study characterised the bacterial microbiome associated with the seawater and Ulva raceways receiving abalone effluent (IMTA system) and compared this to Ulva tanks supplied with fertilised seawater (non-IMTA; control). Ulva samples were collected from each Ulva system, and water samples were collected at the inlet and outlet of each system. Bacterial communities were assessed using a culture-based approach and next-generation sequencing (NGS) of the V3-V4 16S rDNA region. It was observed that Ulva has the potential to reduce the bacterial load of abalone effluent, with the total number of potential culturable Vibrio species declining from 150×103 cells mL-1 in the inlet to 37×103 cells mL-1 in the outlet of the Ulva system. The NGS dataset supported these findings, with a reduction observed in Vibrio and Pseudoalteromonas from the inlet to outlet samples. A lower number of genera (p < 0.05) were observed on Ulva when compared with water samples, indicating that Ulva has a beneficial, modulatory effect on bacteria. These findings contribute towards the growing body of evidence for the benefits of seaweeds in IMTA and addresses the biosecurity concerns of abalone farmers wishing to improve the circularity of their farming activities by incorporating seaweeds.

Metagenomic analysis reveals differential effects of sewage treatment on the microbiome and antibiotic resistome in Bengaluru, India

ABSTRACT Climate change and health are closely linked to urban wastewater used for irrigation. Sewage treatment plants (STPs) provide ideal environments and niche availability for the transmission of antibiotic resistance genes (ARGs) among pathogenic and non-pathogenic bacteria. In this study, we examined the differential effect of sewage processing methods from the inlet to the outlet on the microbial diversity and antibiotic resistomes of 26 STPs in the urban sewage network of Bengaluru, India. We screened 478 ARGs and found 273 in wastewater, including clinically relevant genes such as CTX-M, qnr, sul-1, and NDM-1, which confer resistance to six major classes of antibiotics. The richness of ARGs was higher in sewage inlets compared with outlets. We observed a downward shift in drug classes from inlet to outlet samples, except for aminoglycosides, beta-lactams, MLSB, and tetracycline. Inlet samples exhibited more complex correlations between ARGs and bacteria compared with outlet samples. Our findings serve as a baseline study that could aid in the quantification of genes from both culturable and non-culturable taxa and will assist in the development of policies and strategies to address water quality issues associated with the use of recycled water.

A Battery of Simple Bioassays for Domestic and Industrial Wastewater Treatment Plants in Konya, Turkey

Wastewater ingredients present risks to the environment and can cause health problems. The aim of this study was to identify the toxicological effects of influent and effluent wastewater from Konya Urban Wastewater Treatment Plant (KU WWTP) and Konya Organized Industrial Zone Wastewater Treatment Plant (KOI WWTP). Three different trophic level toxicity tests were conducted to determine the possible harmful effects of wastewater on the environment. The base toxic unit values of the Lepidium sativum toxicity test for the inlet and outlet samples of KU WWTP were found to be 1.43 and 1.10, respectively. Both values classified the analyzed wastewater into the “toxic” category. Wastewater entering the KU wastewater treatment facility was classified as “toxic” for the presence of toxic substances according to the Vibrio fischeri toxicity testing. Influent samples from the KOI wastewater treatment plant were classified as “toxic” with the Vibrio fischeri toxicity test. In addition, based on the fish bioassay value (TDF), wastewater from the KOI treatment facility was also classified as “toxic”. It was concluded that increased chemical oxygen demand and concentrations of total nitrogen and phosphorus and of certain heavy metals above the limits played a decisive role in classifying the samples as “toxic”. The results of this study suggest that all three tests have the potential to assess wastewater toxicity and that changes in wastewater properties may result in differences in test sensitivity.

Non-target analysis for water characterization: wastewater treatment impact and selection of relevant features.

Non-target analyses were conducted to characterize and compare the molecular profiles (UHPLC-HRMS fingerprint) of water samples from a wastewater treatment plant (WWTP). Inlet and outlet samples were collected from three campaigns spaced 6months apart in order to highlight common trends. A significant impact of the treatment on the sample fingerprints was shown, with a 65-70% abatement of the number of features detected in the effluent, and more polar, smaller and less intense molecules found overall compared to those in WWTP influent waters. Multivariate analysis (PCA) associated with variations of the features between inlets and outlets showed that features appearing or increasing were correlated with effluents while those disappearing or decreasing were correlated with influents. Finally, effluent features considered as relevant to a potentially adverse effect on aqueous media (i.e. those which appeared or increased or slightly varied from the influent) were highlighted. Three hundred seventy-five features common with the 3 campaigns were thus selected and further characterized. For most of them, elementary composition was found to be C, H, N, O (42%) and C, H, N, O, P (18%). Considering the MS2 spectra and several reference MS2 databases, annotations were proposed for 35 of these relevant features. They include synthetic products, pharmaceuticals and metabolites.

Occurrence, distribution, and environmental risk of 61 glucocorticoids in surface water of the Yellow River Delta, China

Glucocorticoids (GCs), as important endocrine disrupting compounds and emerging contaminants, could have irreversible adverse effects on aquatic organisms even at ng/L levels. However, previous studies have only focused on the dissolved concentrations of GCs in the water, and limited data are available for their occurrences in the solid phase. In this study, the occurrence, distribution, and environmental risks of 61 natural and synthetic GCs in surface water of the Yellow River Delta (YRD) were simultaneously analyzed by investigating water, suspended particulate matter (SPM) and sediment samples at 64 sites in six major rivers in the wet season. Overall, 51 GCs were detected in all samples from different matrices, and their concentrations were in the range of not detected (ND)−274 ng/L in water, ND−42 ng/g dry weight (dw) in SPM and ND−9.98 ng/g dw in sediment. Natural GCs were the dominant compounds in all samples, followed by synthetic halogenated esters. High concentrations of GCs were observed in discharge outlet samples from livestock farming, aquaculture and industrial production, and the composition differences of GCs between human/animal sources and industrial sources could be used as indicators to identify pollution sources. Most GCs were distributed in the water phase, while compounds with higher log octanol/water partition coefficients (log Kow) tended to be adsorbed to SPM and sediment. The spatial distribution of GCs was primarily affected by anthropogenic activities and hydrodynamic conditions. Four synthetic compounds (budesonide [BD], fluocinolone acetonide [FOA], fluticasone propionate [FP], and clobetasol propionate [CBSP]) were identified as the main contributors to GC activity with a combined contribution of 57 %–95 %. Risk assessment using the risk quotient revealed that low to moderate risks are posed to aquatic organisms in surface water.

PacBio next-generation sequencing uncovers Apicomplexa diversity in different habitats

The phylum Apicomplexa comprises a large group of intracellular protozoan parasites. These microorganisms are known to infect a variety of vertebrate and invertebrate hosts, leading to significant medical and veterinary conditions such as toxoplasmosis, cryptosporidiosis, theileriosis, and eimeriosis. Despite their importance, comprehensive data on their diversity and distribution, especially in riverine environments, remain scant. To bridge this knowledge gap, we utilized next-generation high-throughput 18S rRNA amplicon sequencing powered by PacBio technology to explore the diversity and composition of the Apicomplexa taxa. Principal component analysis (PCA) and principal coordinate analysis (PCoA) indicated the habitat heterogeneity for the physicochemical parameters and the Apicomplexa community. These results were supported by PERMANOVA (P < 0.001), ANOSIM (P < 0.001), Cluster analysis, and Venn diagram. Dominant genera of Apicomplexa in inlet samples included Gregarina (38.54%), Cryptosporidium (32.29%), and Leidyana (11.90%). In contrast, outlet samples were dominated by Babesia, Cryptosporidium, and Theileria. While surface water samples revealed 16% and 8.33% relative abundance of Toxoplasma and Cryptosporidium, respectively. To our knowledge, the next-generation high throughput sequencing covered a wide range of parasites in Egypt for the first time, which could be useful for legislation of the standards for drinking water and wastewater reuse.

Occurrence and Removal of Microplastic in Sewage Treatment Facilities in Chungcheongbuk-do

Microplastics from sewage and wastewater treatment facilities can be discharged into rivers and oceans, and the treatment facilities themselves can be a point source of microplastic pollution. The microplastic detection status and methods were compared in Miwon, Cheongju, Jecheon, and Chungju sewage treatment facilities in Chungcheongbuk-do. Samples were collected from the inlet, filtration facility, and discharge of Miwon Sewage Treatment Facility, a Porous Substrate Bioreactor (PSBR) construction corporation. Additionally, the inlet, first settling tank, final settling tank and outlet samples were taken from three sewage treatment facilities (Cheongju, Jecheon, and Chungju), which use bioreactor transformation processes. In the results, raw water showed a range of 232-1,510 pieces/L, and effluent water showed a range of 0.7-6.7 pieces/L. All four sewage treatment facilities showed high treatment efficiency of 98.5-99.9%. The treatment processes showed high removal efficiency in the order of CNR (97.0%) &gt; PSBR (95.9%) &gt; NPR (91.5%) &gt; SMART3 (70.3%). As a study was conducted on only one sewage treatment facility for each process, additional research is necessary.

Emerging pollutants characterization, mitigation and toxicity assessment of sewage wastewater treatment plant- India: A case study

India faces major challenges related to fresh water supply and the reuse of treated wastewater is an important strategy to combat water scarcity. Wastewater in Gorakhpur, India, is treated by a decentralised wastewater treatment system (DEWATS) and the treated wastewater is reused in the rural area. This research provides important scientific data that ascertain the safety of wastewater reuse in this region. The physicochemical characteristics, including pigment, ionic strength, BOD, COD, TDS, TSS, salinity, total N, ammonium N, phenolics, heavy metals, and sulphate, of the inlet and outlet sewage water samples (SWWs) from a wastewater treatment facility was conducted. These parameters were found to be significantly over the national limit. The inlet and outlet samples were further characterised by using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR) and gas chromatography–mass spectrometry (GC–MS). SEM showed microstructure and the presence of various metals, polymers, and other co-pollutants in the samples and FT-IR confirmed the presence of aldehyde, hard liquor, and nitrogen molecules in the SWW's discharge. Many endocrine disruptors and potentially mutagenic chemical substances (e.g., Dodecane, Hexadecane, Octadecane etc.) were identified in the outlet SWW by the GC–MS analysis. Toxicity of the SWW was assessed via phytotoxicity assessment using Phaseolus mungo L. and histological and biochemical analyses of Heteropneustes fossilis in a 24-h exposure study. Results confirmed the wastewater was harmful and inhibited germination of P. mungo L. by >80% compared to the control, destroyed gill laminae and significantly increased oxidative stress (above 5% increase in catalase production) in H. fossilis. This work clearly demonstrated that the quality of the treated wastewater in Gorakhpur was poor and immediate action is needed before it can be discharged or reused.

Analysis of the Copper (Cu), Chromium (Cr), and Manganese (Mn) Levels from the Steel Industry Liquid Waste by Atomic Absorption Spectrophotometry Method

Liquid waste from the steel industry processing, washing machine, and kitchenware foundry that is disposed containing copper (Cu), chromium (Cr) and manganese (Mn) elements which is harmful to enviromental. The levels of elemental copper (Cu), chromium (Cr), and manganese (Mn) were analyzed using Atomic Absorption Spectrophotometry (AAS) method. The effluent samples were destructed with the addition of concentrated HNO3. Then determining of the concentration of the element copper (Cu), chromium (Cr) and manganese (Mn) using Atomic Absorption Spectrophotometer with a calibration curve. The obtained results for the levels of copper (Cu) on the inlet samples were 0.9714 mg/L - 0.9719 mg/L, the outlet samples were 3.9990 mg/L - 4.0002 mg/L. Hence, the levels of the element chromium (Cr) on inlet samples were 0.0295 mg/L - 0.0297 mg/L, the outlet samples were 0.0399 mg/L - 0.0400 mg/L and the levels of manganese (Mn) in the inlet samples were 0.1269 mg/L - 0.1271 mg/L in a outlet samples were 2.9699 mg/L - 2.9701 mg/L. Then the steel industry wastewater for elemental copper (Cu) and manganese (Mn) has exceeded the limits that have been instituted by the Minister of Environment Decree No. 51, 1995, about the Liquid Waste Quality Standard for Industrial Activity

Evaluation of the Implementation Integrated Biological System Industrial Wastewater Treatment Plant: Pollutant Removal, Operational Maintenance, Estimation of Carbon Emission

The development of WWTP in business activities needs to pay attention to getting appropriate WWTP that is more valuable to support sustainable development. This study aims to evaluate two systems of integrated biological WWTP; anaerobic-wetland, and anaerobic-aerobic-wetland, including the effectiveness of pollutant removal, operational and maintenance, and estimation of carbon emissions. The performance of pollutant removal was evaluated by analyzing inlet and outlet samples of WWTP. An operational and maintenance evaluation was carried out by studying the WWTP operating system and maintenance procedures supported by a literature review. Carbon emission estimation was carried out using a formula referring to the IPCC Guidelines (2006). Organic matter removal of anaerobic-aerobic-wetland WWTP in the form of BOD₅ and COD are 92.12% and 91.72%, respectively, higher than anaerobic-wetland WWTP are 88.69% of BOD₅ and 77.62% of COD. Anaerobic-aerobic-wetland WWTP needs more maintenance and operation than anaerobic-wetland WWTP. The highest carbon emission of both WWTP is 41530.91 kgCO₂ eq/year of anaerobic-wetland WWTP from the organic matter removal process and 46485.15 kgCO₂ eq/year of anaerobic-aerobic-wetland WWTP. Electrical energy consumption emits in anaerobic-aerobic-wetland WWTP is 22338 kgCO₂ eq/year higher than anaerobic-wetland WWTP at 4299.70 kgCO₂ eq/year. Total carbon emissions of anaerobic-wetland WWTP is 47404.58 kgCO₂ eq/year and anaerobic-aerobic-wetland WWTP is 68900.23 kgCO₂ eq/year.

Causes of Industrial Protein A Column Degradation, Explored Using Raman Spectroscopy.

Monoclonal antibodies (mAbs) are used extensively as biotherapeutics for chronic and acute conditions. Production of mAbs is lengthy and expensive, with protein A affinity capture the most costly step, due both to the nature of the resin and its marked reduction in binding capacity with repeated use. Our previous studies using in situ ATR-FTIR spectroscopy indicated that loss in protein A binding capacity is not the result of leaching or degradation of protein A ligand, suggesting fouling is the principal cause. Here we explore binding behavior and resin capacity loss using Raman spectroscopy. Our data reveal a distinct Raman spectral fingerprint for mAb bound to the protein A ligand of MabSelect SuRe. The results show that the drop in static binding capacity (SBC) previously observed for used protein A resin is discernible by Raman spectroscopy in combination with partial least-squares regression. The SBC is lowest (35.76 mg mL-1) for used inlet resin compared to used outlet (40.17 mg mL-1) and unused resin samples (70.35 mg mL-1). Depth profiling by Raman spectroscopy indicates that at below saturating concentrations (∼18 mg mL-1), binding of mAb is not homogeneous through used resin beads with protein binding preferentially to the outer regions of the bead, in contrast to fully homogeneous distribution through unused control MabSelect SuRe resin beads. Analysis of the Raman spectra indicates that one foulant is irreversibly bound mAb. The presence of irreversibly bound mAb and host cell proteins was confirmed by mass spectrometric analysis of used resin beads.

Determination of Chemical Oxygen Demand (COD) Concentration in Domestic Wastewater Using UV-Vis Spectrophotometry Method Based On The Effect Of Reflux Time And Preservation Time

The purpose of determining Chemical Oxygen Demand (COD) in samples of domestic wastewater is to determine the effect of variations in the reflux process time which is set to 0, 30, 60, 90, and 120 minutes as well as with variations in the testing time which are set to 0, 3, and 7 days. Determination of LOD and LOQ using a UV-Vis Spectrophotometer was also carried out and the regression equation y = 0.0003x + 0.0066 with a coefficient of determination (R2) was 0.998 with LOD and LOQ values ​​respectively 40.0416 mg O2/L and 133.4721 mg O2/L. Determination of the effect of reflux time and preservation time on COD levels was carried out statistically, namely the normality test (Kolmogorov-Smirnov Test) and homogeneity test (Levene Test) ending with a two-way ANOVA test with a probability or significance value of the inlet and outlet samples of 0.000 &lt; 0.05 ( ). Reflux time affects COD levels, the longer the reflux time, the higher and more stable COD levels. Preservation time affects the decrease in COD levels, which is the longer the preservation time, the greater the decrease in COD levels.

CPI outlet samples from the CE: a new life for the Point-of-Purchase Survey

This article describes U.S. Bureau of Labor Statistics testing efforts to collect consumer shopping location data in the Consumer Expenditure Surveys. These efforts, which started in 2016, eventually replaced the Telephone Point-of-Purchase Survey as the Consumer Price Index’s primary establishment sampling frame for the Commodities and Services Pricing Survey.

Study of Monitoring Water Quality as Impact of Steam Power Plant (SPP) 3 x 10 MW Tanjung Enim Banko Operational Activities

The construction of power plants is very necessary to anticipate the crisis of electricity resources and always increases every year. Tanjung Enim city has Steam Power Plant (SPP), one of them is Banko SPP which has 3 x 10 MW capacity. It was built to meet the demand for society electrical energy. The existence of this SPP construction can cause environmental degradation such as a decrease in water quality that does not meet environmental quality standards. The decline in environmental quality can also have a direct impact on the community around the Tanjung Enim SPP location. This is due to the existence of SPP operational activities that can produce liquid waste such as boiler blowdown, airheater blowdown, cooling system and domestic waste waterfrom the manufacturing process. This research study aims to analyze water quality around Banko SPP based on the physical and chemical parameters by testing in the laboratory. The approach employed in this study was an experimental method that included laboratory sample and testing. The water quality pollution index (PI) which refers to the Ministerial Decree No. 115/2003 (Environmental Decree) was used to analyze the result of laboratory testing. The water quality samples examined in this study were wastewater treatment plant (WWTP) outlet, river water, and groundwater nearest to the SPP's location. The phenol and chlorine parameters exceeded the quality requirements referred to in the South Sumatra Governor Regulation No. 16 of 2005, according to the findings of laboratory testing of river water samples. The mercury (Hg) parameter in the WWTP outlet samples surpassed the South Sumatra Governor Regulation No. 16 of 2005 quality criteria. Meanwhile, the manganese (Mn) parameter in groundwater samples surpasses the quality requirement established by the Government of South Sumatra Regulation No. 82/ 2001 as Class I clean water quality criteria. The water quality pollution index (PI) method achieves a score of 1.52 with the category of Lightly Polluted. Based on these findings, it can be concluded that the influence of SPP Banko's operations on water contamination is minor.

Quantifying Non‐Thermal Silicate Weathering Using Ge/Si and Si Isotopes in Rivers Draining the Yellowstone Plateau Volcanic Field, USA

AbstractIn active volcanic regions, high‐temperature chemical reactions in the hydrothermal system consume CO2 sourced from magma or from the deep crust, whereas reactions with silicates at shallow depths mainly consume atmospheric CO2. Numerous studies have quantified the load of dissolved solids in rivers that drain volcanic regions to determine chemical weathering rates and atmospheric CO2 consumption rates. However, the balance between thermal and non‐thermal components to riverine fluxes in these areas remains poorly constrained, hindering accurate estimates of atmospheric CO2 consumption rates. Here we use the Ge/Si ratio and the stable silicon isotopes (δ30Si) as tracers for quantifying non‐thermal silicon contributions in rivers draining the Yellowstone Plateau Volcanic Field, USA. The Ge/Si ratio (µmol.mol−1) was determined for seven thermal water samples (183 ± 22), eight rivers (35 ± 23) and six creeks flowing into Yellowstone Lake (5 ± 3) during base flow and during peak water discharge following snowmelt. The δ30Si value (‰) was determined for thermal waters (−0.09 ± 0.04), Yellowstone River at Yellowstone Lake outlet (1.91 ± 0.23) and creek samples (0.82 ± 0.29). The calculated atmospheric CO2 consumption associated with non‐thermal waters flowing through Yellowstone's rivers during peak discharge is ∼3.03 ton.km−2.yr−1, which is ∼2% of the annual mean atmospheric CO2 consumption in other volcanic regions. This study highlights the significance of quantifying seasonal variations in chemical weathering rates for improving estimates of atmospheric CO2 consumption rates in active volcanic regions.

Seasonality of Solute Flux and Water Source Chemistry in a Coastal Glacierized Watershed Undergoing Rapid Change: Wolverine Glacier Watershed, Alaska

AbstractAs glaciers around the world rapidly lose mass, the tight coupling between glaciers and downstream ecosystems is resulting in widespread impacts on global hydrologic and biogeochemical cycling. However, a range of challenges make it difficult to conduct research in glacierized systems, and our knowledge of seasonally changing hydrologic processes and solute sources and signatures is limited. This in turn hampers our ability to make predictions on solute composition and flux. We conducted a broad water sampling campaign in order to understand the present‐day partitioning of water sources and associated solutes in Alaska's Wolverine Glacier watershed. We established a relationship between electrical conductivity and streamflow at the watershed outlet to divide the melt season into four hydroclimatic periods. Across hydroclimatic periods, we observed a shift in nonglacial source waters from snowmelt‐dominated overland and shallow subsurface flow paths to deeper groundwater flow paths. We also observed the shift from a low‐ to high‐efficiency subglacial drainage network and the associated flushing of water stored subglacially with higher solute loads. We used calcium, the dominant dissolved ion, from watershed outlet samples to estimate solute fluxes for each hydroclimatic period across two melt seasons. We found between 40% and 55% of Ca2+ export occurred during the late season rainy period. This partitioning of the melt season coupled with a characterization of the chemical makeup and magnitude of solute export provides new insight into a rapidly changing watershed and creates a framework to quantify and predict changes to solute fluxes across a melt season.

Photocatalytic degradation of amoxicillin from aqueous solutions by titanium dioxide nanoparticles loaded on graphene oxide.

The photocatalytic degradation of amoxicillin (AMX) by titanium dioxide nanoparticles loaded on graphene oxide (GO/TiO2) was evaluated under UV light. Experimental results showed that key parameters such as initial pH, GO/TiO2 dosage, UV intensity, and initial AMX concentration had a significant effect on AMX degradation. Compared to the photolysis and adsorption processes, the AMX degradation efficiency was obtained to be more than 99% at conditions including pH of 6, the GO/TiO2 dosage of 0.4 g/L, the AMX concentration of 50 mg/L, and the intensity of 36 W. Trapping tests showed that all three hydroxyl radical (OH•), superoxide radical (O2•-), and hole (h+) were produced in the photocatalytic process; however, h+ plays a major role in AMX degradation. Under UV irradiation, GO/TiO2 showed excellent stability and recyclability for 4 consecutive reaction cycles. The analysis of total organic carbon (TOC) suggested that AMX could be well degraded into CO2 and H2O. The formation of NH4+, NO3-, and SO42- as a result of AMX degradation confirmed the good mineralization of AMX in the GO/TiO2/UV process. The toxicity of the inlet and outlet samples of the process has been investigated by cultivation of Escherichia coli and Streptococcus faecalis, and the results showed that the condition is suitable for the growth of organisms. The photocatalytic degradation mechanism was proposed based on trapping and comparative tests. Based on the results, the GO/TiO2/UV process can be considered as a promising technique for AMX degradation due to photocatalyst stability, high mineralization efficiency, and effluent low toxicity.