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1.
Sci Total Environ ; 767: 144976, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33636779

RESUMEN

Plastics accumulation in marine ecosystems has notable ecological implications due to their long persistence, potential ecotoxicity, and ability to adsorb other pollutants or act as vectors of pathogens. The present work aimed to evaluate the physiological response of the gilthead seabream (Sparus aurata) fed for 90 days with a diet enriched with virgin and seawater exposed low-density polyethylene microplastics (LDPE-MPs) (size between 100 and 500 µM), followed by 30 days of depuration, applying oxidative stress and inflammatory markers in liver homogenates. No effects of LDPE-MPs treatments on fish growth were observed throughout this study. A progressive increase in antioxidant enzyme activities was observed throughout the study in both treatments, although this increase was higher in the group treated with seawater exposed MPs. This increase was significantly higher in catalase (CAT), glutathione reductase (GRd), and glutathione-s-transferase (GST) in the seawater exposed MPs group, with respect to the virgin group. In contrast, no significant differences were recorded in superoxide dismutase (SOD) and glutathione peroxidase (GPx) between both groups. Exposure to MPs also caused an increase in the oxidative damage markers (malondialdehyde and carbonyls groups). Myeloperoxidase activity significantly increased because of MPs treatments. After 30 days of depuration, antioxidant, inflammatory enzyme activities and oxidative damage markers returned to values similar to those observed in the control group. In conclusion, MPs exposure induced an increase of antioxidant defences in the liver of S. aurata. However, these elevated antioxidant capabilities were not enough to prevent oxidative damage in the liver since, an increased oxidative damage marker was associated with MPs ingestion. The treatment with seawater exposed MPs caused a more significant antioxidant response (CAT, GRs, and GST). Although after a depuration period of 30 days a tendency to recover the initial values of the biomarkers was observed this does not seem to be time enough for a complete normalization.


Asunto(s)
Dorada , Contaminantes Químicos del Agua , Animales , Catalasa/metabolismo , Dieta , Ecosistema , Inflamación , Hígado/química , Microplásticos , Estrés Oxidativo , Plásticos/metabolismo , Plásticos/toxicidad , Dorada/metabolismo , Agua de Mar , Contaminantes Químicos del Agua/análisis
2.
Sci Total Environ ; 767: 145305, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33636788

RESUMEN

Biochar, a carbon-rich material, has been widely used to adsorb a range of pollutants because of its low cost, large specific surface area (SSA), and high ion exchange capacity. The adsorption capacity of biochar, however, is limited by its small porosity and low content of surface functional groups. Nano-metal oxides have a large SSA and high surface energy but tend to aggregate and passivate because of their fine-grained nature. In combining the positive qualities of both biochar and nano-metal oxides, nano-metal oxide-biochar composites (NMOBCs) have emerged as a group of effective and novel adsorbents. NMOBCs improve the dispersity and stability of nano-metal oxides, rich in adsorption sites and surface functional groups, maximize the adsorption capacity of biochar and nano-metal oxides respectively. Since the adsorption capacity and mechanisms of NMOBCs vary greatly amongst different preparations and application conditions, there is a need for a review of NMOBCs. Herein we firstly summarize the recent methods of preparing NMOBCs, the factors influencing their efficacy in the removal of several pollutants, mechanisms underlying the adsorption of different pollutants, and their potential applications for pollution control. Recommendations and suggestions for future studies on NMOBCs are also proposed.


Asunto(s)
Contaminantes Ambientales , Contaminantes Químicos del Agua , Adsorción , Carbón Orgánico , Óxidos , Contaminantes Químicos del Agua/análisis
3.
Sci Total Environ ; 767: 145447, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33636789

RESUMEN

The removal of potentially toxic metals by biochars is currently a popular and salutary method. In this study, we combined the advantages of blue algae (Microcystic) and pyrolysis technology to produce a late-model biochar. Moreover, the adsorption capacity and potential mechanisms of blue algae-derived biochars for the removal of cadmium (Cd) from aqueous solution were evaluated in comparison with the adsorption capacity and potential mechanisms of corn straw-derived biochar (CSBC) and rice husk-derived biochar (RHBC). Batch adsorption experiments were used to explore the adsorption performance of biochars, and a wide range of characterization techniques were employed: scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and zeta potential analysis. The results showed that the adsorption isotherms could be described well by the Langmuir model and that the pseudo-second-order model fit the Cd(II) adsorption kinetics best, indicating that the process was monolayer and controlled by chemisorption. Moreover, the Cd(II) removal capacity of optimal blue algae-derived biochar (BC600-2) (135.7 mg g-1) was 85.9% and 66.9% higher than the removal capacity of CSBC and RHBC, respectively. In addition, the results of the characterization methods showed that precipitation with minerals was the primary mechanism, accounting for 68.7-89.5% of the capacity. Overall, blue algae-derived biochars, as a product from freshwater biowaste, may be a novel and potentially valuable adsorbent for Cd(II) removal.


Asunto(s)
Cadmio , Contaminantes Químicos del Agua , Adsorción , Cadmio/análisis , Carbón Orgánico , Cinética , Contaminantes Químicos del Agua/análisis
4.
Sci Total Environ ; 767: 144699, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33636791

RESUMEN

The present study investigates the cytotoxic and oxidative effects of custom-made nanoparticles (NPs) on hemocytes of Mytilus galloprovincialis, utilizing hemolymph serum (HS) as exposure medium. Specifically, hemocyte lysosomal membrane destabilization (in terms of neutral red retention time assay/NRRT), superoxide anion (O2-), nitric oxide (NO, in terms of nitrites) and lipid peroxidation content (in terms of malondialdehyde/MDA equivalents) were determined in cells treated for 1 h with different concentrations (0.1-50 µg mL-1) of ZnO NPs, Ag NPs and ZnO-Ag NPs, as well as AgNO3 and/or ZnCl2 (bulk ions, respectively). According to the results, Ag NPs were more cytotoxic than ZnO-Ag NPs and/or ZnO NPs, while NRRT values observed in AgNO3 treated cells were lower than those of ZnCl2. Furthermore, high levels of both O2- and MDA were detected in cells treated with Ag NPs, ZnO-Ag NPs, and AgNO3 at concentrations lower than 5 µg mL-1, while high NO generation was observed only in cells treated with 5-25 µg mL-1 of ZnO NPs or ZnCl2. Despite the absence of data, regarding the formation of NP-serum protein corona complexes that could mediate NP surface energy and uptake efficiency, the current study firstly revealed that ZnO NPs, probably via their surface charge, particle agglomeration, and NP Zn+ release could promote an immune-related generation of O2- and NO via the respiratory burst stimulation, a process that is questioned in the case of Ag NPs and/or ZnO-Ag NPs. Moreover, ZnO-Ag NP interaction with biological membranes and their oxidative mode of action seemed to be regulated by the release and the antagonistic/synergistic response of its ionic counterparts (ZnO+ and Ag+), but further studies are needed to elucidate the oxidative mode of action of NP metal ions in complex NP mixtures.


Asunto(s)
Nanopartículas del Metal , Mytilus , Nanopartículas , Contaminantes Químicos del Agua , Óxido de Zinc , Animales , Hemocitos , Nanopartículas del Metal/toxicidad , Estrés Oxidativo , Plata/toxicidad , Contaminantes Químicos del Agua/toxicidad , Óxido de Zinc/toxicidad
5.
Sci Total Environ ; 767: 145425, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33636795

RESUMEN

The bTPMT (bacterial thiopurine S-methyltransferase), encoded by the tpm gene, can detoxify metalloid-containing oxyanions and xenobiotics. The hypothesis of significant relationships between tpm distribution patterns and chemical pollutants found in urban deposits was investigated. The tpm gene was found conserved among eight bacterial phyla with no sign of horizontal gene transfers but a predominance among gammaproteobacteria. A DNA metabarcoding approach was designed for tracking tpm-harboring bacteria among polluted urban deposits and sediments recovered for more than six years in a detention basin (DB). This DB recovers runoff waters and sediments from a zone of high commercial activities. The PCR products from DB samples led to more than 540,000 tpm reads after DADA2 or MOTHUR bio-informatic manipulations that were allocated to more than 88 and less than 634 sequence variants per sample. The tpm community patterns were significantly different between the recent urban deposits and those that had accumulated for more than 2 years in the DB, and between those of the DB surface and the DB settling pit. These groups of samples had distinct mixture of priority pollutants. Significant relationships between tpm ordination patterns, sediment accumulation time periods and location, and concentrations in PAH, chlorpyrifos, and 4-nonylphenols (NP) were observed. These correlations matched the higher occurrences of, among others, Aeromonas, Pseudomonas, and Xanthomonas tpm-harboring bacteria in recent urban DB deposits more contaminated with chrysene and alkylphenol ethoxylates. Highly significant drops in tpm reads allocated to Aeromonas species were recorded in the oldest DB sediments accumulating naphthalene and metallic pollutants. Degraders of urban pollutants such as P. aeruginosa and P. putida showed conserved distribution patterns over time but P. syringae phytopathogens were more abundant in the oldest sediments. TPMT-harboring bacteria can be used to assess the incidence of high risk priority pollutants on environmental systems.


Asunto(s)
Contaminantes Ambientales , Contaminantes Químicos del Agua , Adenosina Desaminasa , Bacterias/genética , Monitoreo del Ambiente , Sedimentos Geológicos , Péptidos y Proteínas de Señalización Intercelular , Metiltransferasas , Contaminantes Químicos del Agua/análisis
6.
J Environ Sci (China) ; 102: 159-169, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33637241

RESUMEN

Nitrated polycyclic aromatic hydrocarbons (NPAHs) have toxic potentials that are higher than those of their corresponding parent polycyclic aromatic hydrocarbons (PAHs) and thus have received increasing attention in recent years. In this study, the occurrence, distribution, source, and human health risk assessment of 15 NPAHs and 16 PAHs were investigated in the surface water from 20 sampling sites of Lake Taihu during the dry, normal, and flood seasons of 2018. The ΣPAH concentrations ranged from 255 to 7298 ng/L and the ΣNPAH concentrations ranged from not-detected (ND) to 212 ng/L. Among the target analytes, 2-nitrofluorene (2-nFlu) was the predominant NPAH, with a detection frequency ranging from 85% to 90% and a maximum concentration of 56.2 ng/L. The three-ringed and four-ringed NPAHs and PAHs comprised the majority of the detected compounds. In terms of seasonal variation, the highest levels of the ΣNPAHs and ΣPAHs were in the dry season and flood season, respectively. Diagnostic ratio analysis indicated that the prime source of NPAHs was direct combustion, whereas in the case of PAHs the contribution was predominantly from a mixed pattern including pollution from unburned petroleum and petroleum combustion. The human health risk of NPAHs and PAHs was evaluated using a lifetime carcinogenic risk assessment model. The carcinogenic risk level of the targets ranged from 2.09 × 10-7 to 5.75 × 10-5 and some surface water samples posed a potential health risk.


Asunto(s)
Hidrocarburos Policíclicos Aromáticos , Contaminantes Químicos del Agua , China , Monitoreo del Ambiente , Humanos , Lagos , Nitratos , Hidrocarburos Policíclicos Aromáticos/análisis , Medición de Riesgo , Agua , Contaminantes Químicos del Agua/análisis
7.
J Environ Sci (China) ; 102: 170-184, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33637242

RESUMEN

Seven popular fluoroquinolone antibiotics (FQs) in synthetic marine aquaculture water were subject to sodium hypochlorite (NaClO) disinfection scenario to investigate their reaction kinetics and transformation during chlorination. Reactivity of each FQ to NaClO was following the order of ofloxacin (OFL) > enrofloxacin (ENR) > lomefloxacin (LOM) > ciprofloxacin (CIP) ~ norfloxacin (NOR) >> pipemedic acid (PIP), while flumequine did not exhibit reactivity. The coexisting chlorine ions and sulfate ions in the water slightly facilitated the oxidation of FQs by NaClO, while humic acid was inhibitable to their degradation. The bromide ions promoted degradation of CIP and LOM, but restrained oxidation of OFL and ENR. By analysis of liquid chromatography with tandem mass spectrometry (LC-MS/MS), eight kinds of emerging brominated disinfection byproducts (Br-DBPs) caused by FQS were primarily identified in the chlorinated synthetic marine culture water. Through density functional theory calculation, the highest-occupied molecular orbital (HOMO) and the lowest-unoccupied molecular orbital (LUMO) characteristic as well as the charge distribution of the FQs were obtained to clarify transformation mechanisms. Their formation involved decarboxylation, ring-opening/closure, dealkylation and halogenation. Chlorine substitution occurred on the ortho-position of FQs's N4 and bromine substitution occurred on C8 position. The piperazine ring containing tertiary amine was comparatively stable, while this moiety with a secondary amine structure would break down during chlorination. Additionally, logKow and logBAF of transformation products were calculated by EPI-SuiteTM to analyze their bioaccumulation. The values indicated that Br-DBPs are easier to accumulate in the aquatic organism relative to their chloro-analogues and parent compounds.


Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Antibacterianos , Bromuros , Cromatografía Liquida , Desinfección , Fluoroquinolonas , Halogenación , Cinética , Hipoclorito de Sodio , Espectrometría de Masas en Tándem , Agua , Contaminantes Químicos del Agua/análisis
8.
J Environ Sci (China) ; 102: 235-243, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33637248

RESUMEN

Biological processes have been widely used for the treatment of both domestic and industrial wastewaters. In such biological processes, pollutants are converted into pollution-free substances by microorganisms through oxidation-reduction reactions. Thus, how to quantify the internal oxidation-reduction properties wastewaters and seek out targeted countermeasures is essential to understand, operate, and optimize biological wastewater treatment systems. So far, no such approach is available yet. In this work, a novel concept of electron neutralization-based evaluation is proposed to describe the internal oxidation-reduction properties of wastewater. Pollutants in wastewater are defined as electron donor substances (EDSs) or electron acceptor substances (EASs), which could give or accept electrons, respectively. With such an electron neutralization concept, several parameters, i.e., electron residual concentration (R), economy-related index (E and Er), and economical evaluation index (Y and Yr), are defined. Then, these parameters are used to evaluate the performance and economic aspects of currently applied wastewater treatment processes and even optimize systems. Three case studies demonstrate that the proposed concept could be effectively used to reduce wastewater treatment costs, assess energy recovery, and evaluate process performance. Therefore, a new, simple, and reliable methodology is established to describe the oxidation-reduction properties of wastewater and assess the biological wastewater treatment processes.


Asunto(s)
Fenómenos Biológicos , Contaminantes Químicos del Agua , Purificación del Agua , Electrones , Oxidación-Reducción , Eliminación de Residuos Líquidos , Aguas Residuales , Contaminantes Químicos del Agua/análisis
9.
J Environ Sci (China) ; 102: 24-36, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33637249

RESUMEN

UV/chlorine process, as an emerging advanced oxidation process (AOP), was effective for removing micro-pollutants via various reactive radicals, but it also led to the changes of natural organic matter (NOM) and formation of disinfection byproducts (DBPs). By using negative ion electrospray ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS), the transformation of Suwannee River NOM (SRNOM) and the formation of chlorinated DBPs (Cl-DBPs) in the UV/chlorine AOP and subsequent post-chlorination were tracked and compared with dark chlorination. In comparison to dark chlorination, the involvement of ClO•, Cl•, and HO• in the UV/chlorine AOP promoted the transformation of NOM by removing the compounds owning higher aromaticity (AImod) value and DBE (double-bond equivalence)/C ratio and causing the decrease in the proportion of aromatic compounds. Meanwhile, more compounds which contained only C, H, O, N atoms (CHON) were observed after the UV/chlorine AOP compared with dark chlorination via photolysis of organic chloramines or radical reactions. A total of 833 compounds contained C, H, O, Cl atoms (CHOCl) were observed after the UV/chlorine AOP, higher than 789 CHOCl compounds in dark chlorination, and one-chlorine-containing components were the dominant species. The different products from chlorine substitution reactions (SR) and addition reactions (AR) suggested that SR often occurred in the precursors owning higher H/C ratio and AR often occurred in the precursors owning higher aromaticity. Post-chlorination further caused the cleavages of NOM structures into small molecular weight compounds, removed CHON compounds and enhanced the formation of Cl-DBPs. The results provide information about NOM transformation and Cl-DBPs formation at molecular levels in the UV/chlorine AOP.


Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Cloro/análisis , Desinfección , Halogenación , Espectrometría de Masas , Contaminantes Químicos del Agua/análisis
10.
J Environ Sci (China) ; 102: 256-262, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33637251

RESUMEN

This study aimed to evaluate the spatial and temporal variations of molybdenum (Mo) in the downstream water body of a Mo mine during three hydrologic periods (wet, dry and medium seasons). The physical properties in Luhun Reservoir reflected seasonal variations in different hydrological periods. The redox potential (ORP) and dissolved oxygen (DO) increased in the dry season. The concomitant decrease in temperature (T), conductivity (COND) and total dissolved solids (TDS) were lowest in the wet season. The pH value did not change significantly during the three hydrologic periods. The distribution of Mo in the dry season was high in upstream and low in downstream areas, which was significantly different from that of the wet and medium seasons. The total Mo concentration in wet (150.1 µg/L) and medium season (148.2 µg/L) was higher than that in the dry season, but the TDS (288.3 mg/L) and the percentage dissolved Mo (81.3%) in overlying water was lowest in the wet season. There was no significant relationship between the dissolved Mo and the total Mo with TDS. In the dry season, the mean total Mo concentration was 116.3 µg/L, which was higher than the standard limit value (70 µg/L) for drinking water (US EPA-United States Environmental Protection Agency recommended value 40 µg/L). Non-point source pollution is the main characteristic of mining area pollution, which was closely related to rainfall. Thus, the Luhun Reservoir contains substantial Mo pollution, which was a significant concern given that it is used as a source of drinking and irrigation water.


Asunto(s)
Monitoreo del Ambiente , Contaminantes Químicos del Agua , China , Minería , Molibdeno , Estaciones del Año , Agua , Contaminantes Químicos del Agua/análisis , Calidad del Agua
11.
J Environ Sci (China) ; 102: 291-300, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33637255

RESUMEN

In this study, a denitrification (DN)-partial nitritation (PN)-anaerobic ammonia oxidation (Anammox) system for the efficient nitrogen removal of mature landfill leachate was built with a zone-partitioning self-reflux biological reactor as the core device, and the effects of changes in seasonal temperature on the nitrogen removal in non-temperature-control environment were explored. The results showed that as the seasonal temperature decreased from 34°C to 11.3°C, the total nitrogen removal rate of the DN-PN-Anammox system gradually decreased from the peak value of 1.42 kg/(m3•day) to 0.49 kg/(m3•day). At low temperatures (<20°C), when the nitrogen load (NLR) of the system is not appropriate, the fluctuation of high NH4+-N concentration in the landfill leachate greatly influenced the stability of the nitrogen removal. At temperatures of 11°C-15°C, the NLR of the system is controlled below 0.5 kg/(m3•day), which can achieve stable nitrogen removal and the nitrogen removal efficiency can reach above 96%. The abundance of Candidatus Brocadia gradually increased with the decrease of temperature. Nitrosomonas, Candidatus Brocadia and Candidatus Kuenenia as the main functional microorganisms in the low temperature.


Asunto(s)
Nitrificación , Contaminantes Químicos del Agua , Amoníaco , Reactores Biológicos , Desnitrificación , Nitrógeno , Oxidación-Reducción , Estaciones del Año , Temperatura
12.
J Environ Sci (China) ; 102: 301-315, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33637256

RESUMEN

A series of novel adsorbents composed of cellulose (CL) with Ca/Al layered double hydroxide (CCxA; where x represent the Ca/Al molar ratio) were prepared for the adsorption of antimony (Sb(V)) and fluoride (F-) ions from aqueous solutions. The CCxA was characterized by Fourier-transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), elemental analysis (CHNS/O), thermogravimetric analysis (TGA-DTA), zeta potential, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) analysis. The effects of varying parameters such as dose, pH, contact time, temperature and initial concentration on the adsorption process were investigated. According to the obtained results, the adsorption processes were described by a pseudo-second-order kinetic model. Langmuir adsorption isotherm model provided the best fit for the experimental data and was used to describe isotherm constants. The maximum adsorption capacity was found to be 77.2 and 63.1 mg/g for Sb(V) and F-, respectively by CC3A (experimental conditions: pH 5.5, time 60 min, dose 15 mg/10 mL, temperature 298 K). The CC3A nanocomposite was able to reduce the Sb(V) and F- ions concentration in synthetic solution to lower than 6 µg/L and 1.5 mg/L, respectively, which are maximum contaminant levels of these elements in drinking water according to WHO guidelines.


Asunto(s)
Nanocompuestos , Contaminantes Químicos del Agua , Adsorción , Antimonio , Celulosa , Fluoruros , Concentración de Iones de Hidrógeno , Hidróxidos , Cinética , Espectroscopía Infrarroja por Transformada de Fourier
13.
J Environ Sci (China) ; 102: 316-325, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33637257

RESUMEN

The biological toxicity of aquatic ecosystems should be considered when assessing the effects of toxicity on the water environment. The aim of this study was to identify the main pollutants in the Baiyangdian (BYD) and the factors that contribute to biological toxicity. We determined various physical and chemical indicators in the surface water of the BYD, including nutrients and heavy metals, and the biological toxicity. We also explored the sources of the main pollutants and how the pollutants contributed to toxicity in the lake, using correlation analysis and an index of the biological toxicity. The results showed that total nitrogen (TN), ammoniacal nitrogen (NH4+-N), chromium (Cr), and zinc (Zn) were the main pollutants in the BYD surface water. The average concentration of Cr was 2.3 times greater than the Class V threshold, and the concentrations at about 65% of the sampling points, mainly those in the southern part of the BYD, exceeded the threshold standard. The average concentration of Zn was 1.25 times higher than the Class V threshold, with the concentrations of about 35% of the samples greater than the threshold concentration. The integrated toxicity of the surface water to luminescent bacteria ranged from 0.51% to 58%, and averaged 24.07%, which was within the range of moderate toxicity. The inhibition rates were high near Diantou (59%) and Duan (51.6%). The pollutant levels in the BYD tend to be related to the population density, with pollution mainly caused by sewage and domestic garbage, with little influence from local industries. Cr and TN were strongly correlated, but the biological toxicity was not correlated with any of the individual environmental indicators, which suggests that the toxicity in the surface water of the BYD reflected the combined effects of the environmental factors, rather than a single factor. The information from this study, about the main pollutants and the relationships between the physical and chemical properties of the surface water in the BYD, can be used to support plans for restoring the BYD.


Asunto(s)
Metales Pesados , Contaminantes Químicos del Agua , China , Ecosistema , Monitoreo del Ambiente , Sedimentos Geológicos , Lagos , Metales Pesados/análisis , Poaceae , Medición de Riesgo , Agua , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
14.
J Environ Sci (China) ; 102: 352-362, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33637260

RESUMEN

The aqueous foam template without any solvent and only using the particles stabilizer has attracted much attention for preparation of the porous adsorbents. Herein, a novel porous adsorbent was fabricated via thermal-initiated polymerization of Pickering aqueous foams, which was stabilized by the natural sepiolite (Sep) and pine pollen, and utilized for the removal of antibiotic from aqueous solution. The stabilizing mechanism of Pickering aqueous foam of that the Sep was modified with the leaching substance from pine pollen and arranged orderly around the bubble to form a dense "shell" structure was revealed. The adsorbents possessed the hierarchical porous structure and excellent adsorption performance for antibiotic of chlorotetracycline hydrochloride (CTC) and tetracycline hydrochloride (TC). The equilibrium adsorption capacities of CTC and TC were achieved with 465.59 and 330.59 mg/g within 60 min at 25°C, respectively. The adsorption process obeyed Langmuir model and pseudo-second-order adsorption kinetic model. This work provided eco-friendly approach for fabricate porous adsorbents for wastewater treatment.


Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Adsorción , Antibacterianos , Cinética , Porosidad
15.
J Environ Sci (China) ; 102: 64-73, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33637266

RESUMEN

Organochlorine pesticides (OCPs) have received much attention due to their toxicity. Reliable methods to monitor their residues in the environment are needed. Here, magnetic polyamidoamine dendrimers were prepared by co-precipitation, Michael addition, and amidation. The magnetic polyamidoamine dendrimers demonstrated good adsorption ability for OCPs-this feature was utilized to construct a sensitive tool for monitoring OCPs in water samples. The proposed method provided remarkable linearity from 0.1 to 500 µg/L and satisfactory limits of detection from 0.012 to 0.029 µg/L. The spiked recoveries of the four target analytes were 91.8%-103.5% with relative standard deviations less than 4.5%. The magnetic materials had good reusability. The results indicated that the resulting method was an efficient, easy, rapid, economical, and eco-friendly tool for monitoring OCPs in aqueous samples.


Asunto(s)
Dendrímeros , Hidrocarburos Clorados , Plaguicidas , Contaminantes Químicos del Agua , Cromatografía Líquida de Alta Presión , Hidrocarburos Clorados/análisis , Fenómenos Magnéticos , Plaguicidas/análisis , Poliaminas , Agua , Contaminantes Químicos del Agua/análisis
16.
J Environ Sci (China) ; 102: 74-84, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33637267

RESUMEN

Fresh water microplastic pollution is of pressing concern globally, but its distribution and sources in reservoirs are poorly documented. Danjiangkou Reservoir is the second largest reservoir in China and is divided into the Han Reservoir and Dan Reservoir. In this work, microplastic abundances and morphological characteristics of the reservoir were investigated. The microplastic abundance of 15 main tributaries of the reservoir was also measured. The vertical distribution (in water column and sediment), horizontal distribution (in Han Reservoir and Dan Reservoir) and source of microplastics were analyzed. Microplastics accumulated in the middle layer of the reservoir, and the size and color of the microplastic particles changed from the surface to the bottom, which implies that surveys of surface water are not enough to determine the microplastic contamination for deep water reservoirs. In the surface water, the microplastic abundance in the Han Reservoir was lower than that in the Dan Reservoir (p < 0.05), but microplastic abundance did not differ significantly in the intermediate and bottom water. Tributaries were one of the main sources of microplastics for Han Reservoir but not for Dan Reservoir. Agricultural cultivation in the hydro-fluctuation belt might be an important source of microplastics in the Dan Reservoir, which should be given additional attention. The results of this study can provide valuable information for developing microplastic sampling strategies in deep water reservoirs. Further studies are recommended to investigate the process through which microplastics in the hydro-fluctuation belt enter the reservoir and the sinking behavior of microplastics in the reservoir.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , China , Monitoreo del Ambiente , Plásticos , Contaminantes Químicos del Agua/análisis
17.
Environ Monit Assess ; 193(3): 122, 2021 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-33580837

RESUMEN

As a historic gold mining area, the City of Benoni has numerous water bodies close to major tailings dams and mine dumps. Here we assess spatial patterns in the sediment geochemistry of five dams and four natural pans within a 5-km radius of the core mining area to determine the degree of contamination7 by mining-associated pollutants. XRF analysis was used with a geoaccumulation index to assess the degree of contamination above background levels. Prevailing winds blow from the north and north-west with less dominant winds from the east. Sediment concentrations of As, Cu, Pb, Ni and Zn are highly correlated across the region, suggestive of a common source. Except for one pan showing evidence of local industrial pollution, the most contaminated sites are the dams to the west of the mine dumps where concentrations of As, Cu, Pb and Zn increase towards the central mining area, with highest trace metal concentrations in Kleinfontein Dam, adjacent to a reworked mine dump. Sites upwind of the central mining area showed little evidence of mining-related contamination. Trace contaminant concentrations in sediments of these dams are much greater than those found in the nearby Springs-Blesbokspruit wetlands adjacent to more recently active mines. The potential risks to aquatic ecosystems and recreational users of these urban and suburban water bodies from these wind-blown, legacy mining contaminants merit further investigation.


Asunto(s)
Metales Pesados , Contaminantes del Suelo , Oligoelementos , Contaminantes Químicos del Agua , Ecosistema , Monitoreo del Ambiente , Sedimentos Geológicos , Oro , Metales Pesados/análisis , Minería , Contaminantes del Suelo/análisis , Sudáfrica , Contaminantes Químicos del Agua/análisis
18.
Environ Monit Assess ; 193(3): 119, 2021 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-33569704

RESUMEN

Coastal lagoons are among the most vulnerable ecosystems as they are often exposed to different anthropogenic activities. The Polychaetes, which are dominant components in macrobenthic community, are particularly exposed to contamination. The current study was designed to assess and compare the sensitivity of different polychaetes species towards urban pollution. To do this, three polychaete species: Perinereis cultrifera, Diopatra neapolitana, and Marphysa sanguinea, were collected from the Tunis South Lagoon during summer 2013. A set of biomarkers indicative of genotoxicity (DNA damage), biotransformation, and oxidative stress (glutathione S-transferase, GST) as well as immune response (cyclooxygenase activity (COX), lysozyme activity, and nitric oxide level (NOx)), was used. The results revealed that D. neapolitana and P. cultrifera exhibited higher genetic alteration and GST activity and more prominent immune response when compared with M. sanguinea. These findings denote of the higher sensitivity of D. neapolitana and P. cultrifera to urban pollution and suggest their possible use in environmental biomonitoring programs.


Asunto(s)
Poliquetos , Contaminantes Químicos del Agua , Animales , Biomarcadores/metabolismo , Ecosistema , Monitoreo del Ambiente , Estrés Oxidativo , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
19.
Dis Aquat Organ ; 143: 79-100, 2021 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-33570042

RESUMEN

The response of macrophage aggregates in fish to a variety of environmental stressors has been useful as a biomarker of exposure to habitat degradation. Total volume of macrophage aggregates (MAV) was estimated in the liver and spleen of white perch Morone americana from Chesapeake Bay using stereological approaches. Hepatic and splenic MAV were compared between fish populations from the rural Choptank River (n = 122) and the highly urbanized Severn River (n = 131). Hepatic and splenic MAV increased with fish age, were greater in females from the Severn River only, and were significantly greater in fish from the more polluted Severn River (higher concentrations of polycyclic aromatic hydrocarbons, organochlorine pesticides, and brominated diphenyl ethers). Water temperature and dissolved oxygen had a significant effect on organ volumes, but not on MAV. Age and river were most influential on hepatic and splenic MAV, suggesting that increased MAV in Severn River fish resulted from chronic exposures to higher concentrations of environmental contaminants and other stressors. Hemosiderin was abundant in 97% of spleens and was inversely related to fish condition and positively related to fish age and trematode infections. Minor amounts of hemosiderin were detected in 30% of livers and positively related to concentrations of benzo[a]pyrene metabolite equivalents in the bile. This study demonstrated that hepatic and splenic MAV were useful indicators in fish from the 2 tributaries with different land use characteristics and concentrations of environmental contaminants. More data are needed from additional tributaries with a wider gradient of environmental impacts to validate our results in this species.


Asunto(s)
Lubina , Enfermedades de los Peces , Contaminantes Químicos del Agua , Animales , Bahías , Monitoreo del Ambiente , Femenino , Macrófagos , Ríos
20.
Bioresour Technol ; 326: 124753, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33545628

RESUMEN

Acetaminophen (ACE), cephalexin (CPX), and valsartan (VAL) are recognized water pollutants, which can be removed by adsorption. Herein, the removal of these pharmaceuticals using a biochar (BP), prepared from oil palm fiber, was tested. It was studied the structural effects of the pharmaceuticals and biochar on the adsorption process supported by experimental and computational results, plus characterizations of the material. The biochar has 76.05 m2 g-1 of surficial area, and carboxylic groups (1.343 mmol g-1) predominantly. The maximum adsorption uptakes were 7.3, 7.9, and 23.85 mg g-1 for ACE, CPX, and VAL, respectively; following pseudo-second-order kinetics. The best pollutants removal was obtained at acidic pH (3.0). Computational analyses indicated that oxygenated groups of BP (able to generate H-bond interactions) influenced the adsorption of pharmaceuticals. It can be remarked that BP is a low-cost adsorbent synthesized easily from wastes, with high feasibility to remove pharmaceutical structures from water.


Asunto(s)
Preparaciones Farmacéuticas , Contaminantes Químicos del Agua , Adsorción , Carbón Orgánico , Concentración de Iones de Hidrógeno , Cinética , Agua , Contaminantes Químicos del Agua/análisis
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