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1.
Environ Pollut ; 337: 122529, 2023 Nov 15.
Article in English | MEDLINE | ID: mdl-37690468

ABSTRACT

Microbial community, as the decomposers of constructed wetland (CW), plays crucial role in biodegradation and biotransformation of pollutants, nutrient cycling and the maintenance of ecosystem balance. In this study, 9 water samples, 6 sediment samples, and 8 plant samples were collected in Annan CW, which has the functions of water treatment and wetland culture park. The characteristics of microbial community structure in different media were illustrated by using of high-throughput sequencing-based metagenomics approach and statistical analysis. Meanwhile, this study identified and classified human pathogens in CW to avoid potential risks to human health. The results showed that dominant bacteria phyla in CW include Proteobacteria, Bacteroides, Actinobacteria, Firmicutes and Verrucomicrobia. The distribution of microorganisms in three media is different, but not significant. And the pH and DO profoundly affected microbe abundance, followed by water temperature. The microbial diversity in sediments is the highest, which is similar with the detection of human pathogens in sediments. Moreover, compared with Calamus, Lythrum salicaria and Reed, Scirpus tabernaemontani has fewer pathogenic microorganisms. The distribution of microorganisms in the CW is complex, and a variety of human pathogens are detected, which is more prone to create potential risks to human health and should receive additional attention.


Subject(s)
Microbiota , Wetlands , Humans , Beijing , Bacteria/genetics , China
2.
Int J Biol Sci ; 19(5): 1616-1632, 2023.
Article in English | MEDLINE | ID: mdl-37056933

ABSTRACT

Cancer progression depends on the communication between tumor cells and tumor microenvironment. Cancer-associated fibroblasts (CAFs) are a major component of stromal cells. CAFs promote cancer metastasis; however, it has not been evaluated whether N6-methyladenosine (m6A) modification is responsible for CAFs' role in metastasis. In the present study, we found that CAFs promoted migration and invasion of non-small cell lung cancer (NSCLC) cells by elevating m6A modification in NSCLC cells. Methyltransferase-like 3 (METTL3) in NSCLC cells mediated CAFs' effect on m6A modification, and was regulated by CAFs-secreted vascular endothelial growth factor A (VEGFA). METTL3 knockdown in NSCLC cells dramatically inhibited cell migration and invasion, and suppressed tumor growth in vivo. Database analysis revealed that METTL3 was associated with poor prognosis of lung cancer. The mechanism study showed that METTL3 increased m6A level of RAC3 mRNA, resulting in increased stability and translation of RAC3 mRNA. RAC3 was responsible for the CAFs' promoting effect on cell migration via the AKT/NF-κB pathway. This study established a CAF-METTL3-RAC3 m6A modification-dependent regulation system in NSCLC metastasis, suggesting potential candidates for metastasis treatment.


Subject(s)
Cancer-Associated Fibroblasts , Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Humans , Cancer-Associated Fibroblasts/metabolism , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Lung Neoplasms/metabolism , Methyltransferases/genetics , Methyltransferases/metabolism , rac GTP-Binding Proteins/metabolism , RNA, Messenger/metabolism , Tumor Microenvironment , Vascular Endothelial Growth Factor A/metabolism
3.
Ecotoxicol Environ Saf ; 241: 113747, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35709670

ABSTRACT

The effect of dissolved organic matter (DOM) on metal bioavailability and toxicity is a complex process. Effluents from galvanizing plants containing large amounts of DOM and Zn were selected to investigate the potential influence and mechanism of DOM on Zn bioavailability and its role in inducing thyroid hormone disrupting effects. Thyroid hormone disrupting effects were evaluated using a recombinant thyroid hormone receptor ß gene yeast assay. The results suggest that Zn could be the main metal contributor to the toxic effects. Then, Zn-binding characteristics with different fluorescent components of DOM were analyzed using three-dimensional excitation emission matrix fluorescence spectroscopy (3DEEM) and revealed that Zn was more susceptible to interactions with fulvic-like materials. Furthermore, DOM altered the cellular biouptake and compartmentalization processes of Zn by downregulating Zn transmembrane transport-related genes (ZRT1, ZRT2 and ZAP1) and upregulating detoxification-related genes (COT1 and ZRC1), thus altering thyroid toxicity. These results provide comprehensive insights into the influence and mechanism of DOM on bioavailability and thyroid toxicity of Zn and suggest that the influence is associated with complex physical, chemical and biological processes, indicating that more refined medium constraints along with subtle biological reactions should be considered when predicting the bioavailability and toxicity of Zn in environmental water samples.


Subject(s)
Dissolved Organic Matter , Zinc , Biological Availability , Endocrine Disruptors/toxicity , Humic Substances/analysis , Organic Chemicals , Spectrometry, Fluorescence/methods , Thyroid Gland/chemistry , Thyroid Hormones , Water Pollutants/toxicity , Zinc/toxicity
4.
Sci Total Environ ; 836: 155715, 2022 Aug 25.
Article in English | MEDLINE | ID: mdl-35525365

ABSTRACT

Based on in vitro and in silico assays as well as proteome analysis, this study explored the nongenomic mechanism for butyl benzyl phthalate (BBP)-induced thyroid disruption. Molecular docking simulations showed that BBP could dock into the Arg-Gly-Asp (RGD) domain of integrin αvß3 and form hydrogen bonds with a docking energy of -35.80 kcal/mol. This chemical enhanced rat pituitary tumor cell (GH3) proliferation and exhibited thyroid hormone-disrupting effects at 5-10 µmol/L. Meanwhile, BBP upregulated ß3 gene expression and activated the downstream mitogen-activated protein kinase (MAPK) pathway in GH3 cells. Interestingly, GH3 cell proliferation was attenuated by integrin αvß3 inhibitor (RGD peptide) or ERK1/2 inhibitor (PD98059), suggesting that the disruptions might be partly attributed to its interaction with integrin αvß3 and activation of MAPK. Furthermore, quantitative proteomic analysis of zebrafish embryos exposed to BBP at an environmentally relevant concentration of 0.3 µmol/L revealed that BBP perturbed proteins and pathways related to cell communication (e.g., integrin binding) and signal transduction (e.g., MAPK signaling pathway). Taken together, our results supported that the biological effects of BBP-activated integrin αvß3 mediated by the nongenomic pathway play an important role in its thyroid disruption. CAPSULE: The nongenomic pathway plays a vital role in the thyroid disruption-inducing actions of BBP.


Subject(s)
Phthalic Acids , Thyroid Gland , Animals , Integrin alphaVbeta3/genetics , Integrin alphaVbeta3/metabolism , Mitogen-Activated Protein Kinases/metabolism , Molecular Docking Simulation , Phthalic Acids/metabolism , Phthalic Acids/toxicity , Proteome/metabolism , Proteomics , Rats , Zebrafish/metabolism
5.
Cell Death Dis ; 12(10): 858, 2021 09 22.
Article in English | MEDLINE | ID: mdl-34552063

ABSTRACT

Tumor progression requires the communication between tumor cells and tumor microenvironment (TME). Cancer-associated fibroblasts (CAFs) are major components of stromal cells. CAFs contribute to metastasis process through direct or indirect interaction with tumor cells; however, the underlying mechanism is largely unknown. Here, we reported that autophagy was upregulated in lung cancer-associated CAFs compared to normal fibroblasts (NFs), and autophagy was responsible for the promoting effect of CAFs on non-small cell lung cancer (NSCLC) cell migration and invasion. Inhibition of CAFs autophagy attenuated their regulation on epithelial-mesenchymal transition (EMT) and metastasis-related genes of NSCLC cells. High mobility group box 1 (HMGB1) secreted by CAFs mediated CAFs' effect on lung cancer cell invasion, demonstrated by using recombinant HMGB1, HMGB1 neutralizing antibody, and HMGB1 inhibitor glycyrrhizin (GA). Importantly, the autophagy blockade of CAFs revealed that HMGB1 release was dependent on autophagy. We also found HMGB1 was responsible, at least in part, for autophagy activation of CAFs, suggesting CAFs remain active through an autocrine HMGB1 loop. Further study demonstrated that HMGB1 facilitated lung cancer cell invasion by activating the NFκB pathway. In a mouse xenograft model, the autophagy specific inhibitor chloroquine abolished the stimulating effect of CAFs on tumor growth. These results elucidated an oncogenic function for secretory autophagy in lung cancer-associated CAFs that promotes metastasis potential, and suggested HMGB1 as a novel therapeutic target.


Subject(s)
Autophagy , Cancer-Associated Fibroblasts/metabolism , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , HMGB1 Protein/metabolism , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , NF-kappa B/metabolism , Adenine/analogs & derivatives , Adenine/pharmacology , Autophagy/drug effects , Autophagy/genetics , Autophagy-Related Protein 5/metabolism , Cancer-Associated Fibroblasts/pathology , Carcinoma, Non-Small-Cell Lung/genetics , Cell Line, Tumor , Cell Movement/drug effects , Cell Movement/genetics , Cell Proliferation/drug effects , Chloroquine/pharmacology , Epithelial-Mesenchymal Transition/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Humans , Lung Neoplasms/genetics , Microtubule-Associated Proteins/metabolism , Models, Biological , Neoplasm Invasiveness , Neoplasm Metastasis , Recombinant Proteins/pharmacology , Signal Transduction/drug effects
6.
Front Cell Dev Biol ; 9: 764151, 2021.
Article in English | MEDLINE | ID: mdl-34977016

ABSTRACT

Cancer-associated fibroblasts (CAFs) are major component of tumor microenvironment (TME), which plays crucial roles in tumor growth, invasion and metastasis; however, the underling mechanism is not fully elucidated. Despite many studies are focused on the tumor promoting effect of CAFs-derived cytokines, the upstream regulators of cytokine release in CAFs is largely unknown. Here we found that miR-101-3p was downregulated in primary lung cancer-associated CAFs compared to normal fibroblasts (NFs). Ectopic overexpression of miR-101-3p suppressed CAFs activation, and abrogated the promoting effect of CAFs on migration and invasion of non-small cell lung cancer cells (NSCLC), through attenuating CAFs' effect on epithelial mesenchymal transition (EMT) process, metastasis-related genes (MMP9, TWIST1) and AKT/endothelial nitric oxide synthase (eNOS) signaling pathway. Further study indicated that vascular endothelial growth factor A (VEGFA) was a novel target of miR-101-3p, and CAFs-derived VEGFA mediated the effect of miR-101-3p on migration and invasion of lung cancer cells, demonstrated by using recombinant VEGFA and VEGFA neutralizing antibody. Interestingly, the analysis of the Cancer Genome Atlas (TCGA) database revealed that lung cancer tissues expressed lower level of miR-101-3p than non-cancerous tissues, and low/medium-expression of miR-101-3p was associated with poor overall survival (OS) rate. Moreover, the mouse xenograft experiment also showed that CAFs accelerated tumor growth whereas miR-101-3p diminished CAFs' effect. These findings revealed a novel mechanism that CAFs facilitated lung cancer metastasis potential via miR-101-3p/VEGFA/AKT signaling pathway, suggesting miR-101-3p as a potential candidate for metastasis therapy.

7.
Int J Mol Med ; 45(5): 1616-1626, 2020 May.
Article in English | MEDLINE | ID: mdl-32323737

ABSTRACT

[Su(var)3­9, enhancer of zeste, Trithorax] domain­â€‹containing protein 7 (SETD7) is a protein lysine methyltransferase that methylates both histone H3K4 and non­histone proteins, such as transcription factors. The methylation on proteins alters their activity and affects a series of biological processes. Recent studies have demonstrated that SETD7 contributes to tumor progression and may play different roles in tumor development. However, the effect of SETD7 on lung cancer cell migration and invasion has not been fully elucidated. The present study demonstrated that the expression of SETD7 was significantly downregulated in lung cancer tissues in comparison with that in matched non­cancer tissues, and lung cancer cell lines also exhibited lower SETD7 levels compared with normal human bronchial epithelial cells. Overexpression of SETD7 inhibited the migration and invasion of lung cancer cells, whereas decreased SETD7 expression promoted cell migration and invasion. Further study revealed that SETD7 regulated the expression of the metastasis­related genes metalloproteinase 2, Twist1 and vascular endothelial growth factor. Furthermore, SETD7 knockdown activated the Janus kinase 2/signal transducer and activator of transcription 3 (STAT3) signaling pathway and enhanced lung cancer cell migration, whereas the STAT3­specific inhibitor Stattic abrogated the effect of SETD7 on cell migration. Taken together, these data indicated that SETD7 acts as a tumor suppressor, and the reduced expression of SETD7 may contribute to lung cancer progression. The findings of the present study suggest that SETD7 may be a novel candidate for the treatment of metastatic lung cancer.


Subject(s)
Cell Movement/genetics , Down-Regulation/genetics , Histone-Lysine N-Methyltransferase/genetics , Janus Kinase 2/genetics , Lung Neoplasms/genetics , Neoplasm Invasiveness/genetics , STAT3 Transcription Factor/genetics , A549 Cells , Adult , Aged , Aged, 80 and over , Bronchi/metabolism , Cell Line, Tumor , Epithelial Cells/metabolism , Female , Humans , Lung Neoplasms/metabolism , Male , Matrix Metalloproteinase 2/genetics , Middle Aged , Signal Transduction/genetics , Vascular Endothelial Growth Factor A/genetics
8.
Onco Targets Ther ; 13: 2711-2723, 2020.
Article in English | MEDLINE | ID: mdl-32280245

ABSTRACT

BACKGROUND: Cancer-associated fibroblasts (CAFs) are an essential component of tumor microenvironment. They are attracting increasing attentions due to their crucial role in tumor growth, drug-resistance and metastasis. Cisplatin is a first-line chemotherapy drug applying in various types of cancer. There are intensive studies on cisplatin's effect on tumor cells, however, its effect on CAFs remains poorly understood. In the present study, we investigated the effect of cisplatin on CAFs. METHODS: Cell migration was detected by wound healing assay. Cell invasion was performed by the transwell assay. mRNA expression was detected by quantitative PCR, and protein expression was detected by Western blotting. Tumor growth was measured using BALB/c nude mice tumor models. RESULTS: Cisplatin attenuated the promoting capacity of CAFs on lung cancer cell migration and invasion, via suppressing CAFs' effect on metastasis-related genes including Twist1, vascular endothelial growth factor receptor (VEGFR), MMP2, and AKT signaling pathway. Keratin 8 (KRT8) was identified as a target of cisplatin. KRT8 upregulation in CAFs is responsible for the inhibitory effect of cisplatin on lung cancer cells metastasis potential through AKT pathway suppression. The stimulation of AKT by AKT activator SC79 reversed KRT8's effect on cell migration. Importantly, in vivo study also showed that CAFs enhanced tumor growth significantly, and cisplatin effectively abrogated the promoting effect of CAFs on tumor growth. CONCLUSION: Our results revealed a novel mechanism that cisplatin attenuated the metastasis promoting effect of CAFs via KRT8/AKT signaling pathway. This finding highlights KRT8 in CAFs as a potential therapeutic candidate for metastasis treatment.

9.
Mol Carcinog ; 59(6): 590-603, 2020 06.
Article in English | MEDLINE | ID: mdl-32189414

ABSTRACT

Isothiocyanates (ITCs) are natural compounds abundant in cruciferous vegetables. Numerous studies have shown that ITCs exhibit anticancer activity by affecting multiple pathways including apoptosis and oxidative stress, and are expected to be developed into novel anticancer drugs. In our previous studies, we demonstrated that ITCs effectively inhibit the proliferation of non-small cell lung cancer (NSCLC) cells, also induce apoptosis and autophagy. In the present study, we found that phenethyl isothiocyanate (PEITC) had significant synergistic effects with epidermal growth factor receptor tyrosine kinase inhibitor Gefitinib in NSCLC cell lines NCI-H1299 and SK-MES-1; and the degradation of antiapoptotic factor myeloid cell leukemia 1 (Mcl-1) caused by PEITC treatment played key roles in the sensitivity of NSCLC cells to Gefitinib. We further illustrated that PEITC regulated the expression of Mcl-1 through protein kinase RNA-like endoplasmic reticulum kinase (PERK)-eukaryotic translation initiation factor 2α-CHOP-Noxa pathway by a posttranscriptional modulation. Pretreatment with endoplasmic reticulum stress (ER stress) inhibitor tauroursodeoxycholic acid and knockdown of PERK expression attenuated the degradation of Mcl-1 caused by PEITC. In in vivo study, nude mice bearing NCI-H1299 xenograft were administrated with PEITC (50 mg/kg, ip) and Gefitinib (50 mg/kg, ig) for 15 days, the PEITC-Gefitinib combination treatment resulted in a significant synergistic reduction in tumor growth, and significantly induced both ER stress and Mcl-1 degradation in tumor tissues. In conclusion, we explored the prospect of PEITC in improving the efficacy of targeted drug therapy and demonstrated the synergistic effects and underlined mechanisms of PEITC combined with Gefitinib in NSCLC cells treatment. This study provided useful information for developing novel therapy strategies by combination treatment of PEITC with targeted drugs.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Apoptosis/drug effects , Carcinoma, Non-Small-Cell Lung/pathology , Drug Synergism , Endoplasmic Reticulum Stress/drug effects , Myeloid Cell Leukemia Sequence 1 Protein/metabolism , Animals , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/metabolism , Cell Proliferation , Drug Resistance, Neoplasm/drug effects , Female , Gefitinib/administration & dosage , Humans , Isothiocyanates/administration & dosage , Lung Neoplasms/drug therapy , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Mice , Mice, Inbred BALB C , Mice, Nude , Myeloid Cell Leukemia Sequence 1 Protein/genetics , Oxidative Stress , Reactive Oxygen Species/metabolism , Tumor Cells, Cultured , Xenograft Model Antitumor Assays
10.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-825749

ABSTRACT

@#[Abstract] Objective: To investigate the molecular mechanism of microRNA-101 (miR-101) inhibiting the migration and invasion of non-small cell lung cancer (NSCLC) via targeting fibroblast growth factor 2 (FGF2). Methods: qPCR was used to detect the expression levels of miR-101 and FGF2 in human normal lung epithelial BEAS-2B cells and NSCLC cell lines (A549, H661 and SK-MES-1) as well as A549 cells after transfection. MiR-NC, miR-101 mimics, miR-IN-NC, miR-101 inhibitor or pcDNA-3.1 empty plasmid, pcDNA-FGF2 were respectively transfected into A549 cells. Wound healing assay and Transwell assay were used to examine the effects of overexpression of miR-101 and FGF2 on the migration and invasion of A549 cells. Western blotting(WB) was used to detect the expression levels of FGF2, E-cadherin, N-cadherin, Vimentin, ERK1/2 and p-ERK1/2 in A549 cells in each group. Results: The expression level of miR-101 in NSCLC cell lines were significantly lower than that in normal lung epithelial cells (all P<0.05), while the expression level in A549 cells was the lowest. Overexpression of miR-101 significantly inhibited the migration (P<0.05) and invasion (P<0.01) of A549 cells, increased the expression level of E-cadherin but decreased the expression level of Vimentin (P<0.05),N-cadherin (P<0.01) and p-ERK1/2 (P<0.05). Inhibition of miR-101 significantly enhanced the invasion and migration of A549 cells (all P<0.05), decreased the expression level of E-cadherin but increased the expression levels of Vimentin, N-cadherin and p-ERK1/2 (all P<0.05). The results of WB and Dual-luciferase reporter gene assay verified that FGF2 is a direct target gene of miR-101, and over‐expression of FGF2 significantly enhanced the invasion and migration of A549 cells (all P<0.01), decreased the expression of E-cadherin (P<0.01) but increased the expressions of Vimentin (P<0.01), N-cadherin (P<0.05) and p-ERK1/2 (P<0.01). Compared with the FGF2 overexpression alone group, co-overexpression of miR-101 and FGF2 significantly reduced the invasion and migration of A549 cells (all P<0.01), increased the expression of E-cadherin (P<0.01), and decreased the expressions of Vimentin (P<0.01), N-cadherin (P<0.05) and p-ERK1/2 (P<0.01). Conclusion: By targeting FGF2, miR-101 inhibits the invasion and migration of NSCLC cells through suppressing the epithelial-mesenchymal transition (EMT) and ERK signaling pathway.

11.
Ground Water ; 57(3): 430-442, 2019 05.
Article in English | MEDLINE | ID: mdl-29934945

ABSTRACT

Hydrogeochemical evolution of interactions between surface water and groundwater is crucial for guaranteeing water supply quality in a riverside water source area. This study focuses on the seasonal and spatial characteristics of hydrogeochemical evolution affected by groundwater exploitation in the Hulan water source area using hydrochemical analyses and stable isotope tracers. Results show that the concentrations of major ions and total dissolved solids (TDS) increase considerably during the dry season. A bicarbonate water type is primarily produced by the dissolution of calcite, dolomite and gypsum, as well as the cation exchange and human activities. Along the typical infiltration path, the proportions of surface water increase with proximity to the river from 8%-63% during the wet season to 11%-84% during the dry season, which are attributed to an increased hydraulic gradient by exploitation. The typical path is classified into two zones. The first is the intensive mixing zone (within 1 km) with increasing concentrations of major ions and TDS due to mixing effect. The second is the exploitation influence zone (1-3.3 km) with increased concentrations of Ca2+ , Mg2+ , SO4 2- , and HCO3 - during the dry season due to two reasons of seasonal variations in evaporation, stronger water-rock interactions and mixing effects with increased surface water by exploitation.


Subject(s)
Groundwater , Water Pollutants, Chemical , Environmental Monitoring , Humans , Rivers , Water , Water Quality
12.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-793190

ABSTRACT

@#Cancer-associated fibroblasts (CAFs) are one of the major cellularcomponents in tumor microenvironment (TME), which play an important role in cancer progression. MicroRNAs (miRNAs) could participate in the process of CAFs, transformation and metabolism reprogramming, affect the stemness of CAFs, and regulate CAFs-mediated tumor cell proliferation, invasion and chemotherapy resistance; and studies have shown that miRNAs play an important role in CAFs formation and the regulation of CAFs on tumors. The miRNAs released by CAFs can be used as reference indicators for tumor diagnosis, prognosis and drug selection. Thus, exploring the role of miRNAs in the interaction between CAFs and tumor cells and underlining the mechanism, is of great significancefor understanding the occurrence and development of tumors, as well as providing novel strategy for cancer treatment. This review will summarize the role of miRNAs in the formation of CAFs and the regulation of CAFs on tumor cells.

13.
Huan Jing Ke Xue ; 39(9): 4086-4095, 2018 Sep 08.
Article in Chinese | MEDLINE | ID: mdl-30188049

ABSTRACT

Riverbank filtration is internationally accepted as a safe new method for extracting drinking water. This paper describes the structure and characteristics of pollution sources in the Hulan water source area of Harbin during wet and dry seasons, based on groundwater pollution sources apportionment technology. Pollution risk of the water source area was also assessed using the pollution sources-pathway-receptor model. Impacts on water quality safety under the collective effects of seasonal changes and human activities were then analyzed. Results showed that groundwater pollution sources have different spatial distribution characteristics based on pollution source apportionment during wet and dry seasons, with four principal influencing factors:①water-rock interaction caused by exploitation of water sources, ② natural geological processes resulting from dissolution of iron manganese minerals, and pollution by ③ nitrogen and ④ organics in response to human activities. Pollution risk assessment showed that water sources were at low risk during both wet and dry seasons. However, the south area of the water source area showed high groundwater pollution risk during the wet season, while other high-risk areas were mainly distributed around the riverbanks and densely populated areas during the dry season. These findings indicate that human activities greatly influence groundwater pollution risk during the dry season; accordingly, this season should be the focus of integrated water quality management and control for the water source area.

14.
J Contam Hydrol ; 211: 39-48, 2018 04.
Article in English | MEDLINE | ID: mdl-29551242

ABSTRACT

The objective of this study was to explore the controlling factors on the migration and transformation of nitrogenous wastes in groundwater using long-term observations from a contaminated site on the southwestern edge of the Tengger Desert in northwestern China. Contamination was caused by wastewater discharge rich in ammonia. Two long-term groundwater monitoring wells (Wells 1# and 2#) were constructed, and 24 water samples were collected. Five key indicators were tested: ammonia, nitrate, nitrite, dissolved oxygen, and manganese. A numerical method was used to simulate the migration process and to determine the migration stage of the main pollutant plume in groundwater. The results showed that at Well 1# the nitrogenous waste migration process had essentially been completed, while at Well 2# ammonia levels were still rising and gradually transitioning to a stable stage. The differences for Well 1# and Well 2# were primarily caused by differences in groundwater flow. The change in ammonia concentration was mainly controlled by the migration of the pollution plume under nitrification in groundwater. The nitrification rate was likely affected by changes in dissolved oxygen and potentially manganese.


Subject(s)
Groundwater/analysis , Nitrogen/analysis , Water Pollutants, Chemical/analysis , Ammonia/analysis , China , Desert Climate , Environmental Monitoring , Groundwater/chemistry , Manganese/analysis , Nitrates/analysis , Nitrification , Nitrites/analysis , Oxygen/analysis , Wastewater/chemistry , Water Wells
15.
Article in English | MEDLINE | ID: mdl-29415516

ABSTRACT

Globally, groundwater resources are being deteriorated by rapid social development. Thus, there is an urgent need to assess the combined impacts of natural and enhanced anthropogenic sources on groundwater chemistry. The aim of this study was to identify seasonal characteristics and spatial variations in anthropogenic and natural effects, to improve the understanding of major hydrogeochemical processes based on source apportionment. 34 groundwater points located in a riverside groundwater resource area in northeast China were sampled during the wet and dry seasons in 2015. Using principal component analysis and factor analysis, 4 principal components (PCs) were extracted from 16 groundwater parameters. Three of the PCs were water-rock interaction (PC1), geogenic Fe and Mn (PC2), and agricultural pollution (PC3). A remarkable difference (PC4) was organic pollution originating from negative anthropogenic effects during the wet season, and geogenic F enrichment during the dry season. Groundwater exploitation resulted in dramatic depression cone with higher hydraulic gradient around the water source area. It not only intensified dissolution of calcite, dolomite, gypsum, Fe, Mn and fluorine minerals, but also induced more surface water recharge for the water source area. The spatial distribution of the PCs also suggested the center of the study area was extremely vulnerable to contamination by Fe, Mn, COD, and F-.


Subject(s)
Groundwater/standards , Seasons , Water Pollutants, Chemical , Water Pollution/statistics & numerical data , Water Quality , Agriculture , China , Environmental Monitoring/methods , Groundwater/analysis , Principal Component Analysis , Spatial Analysis , Water Pollutants, Chemical/analysis , Water Pollution/analysis
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