Serious groundwater pollution not only affects the development of enterprises but also threatens the life and health of residents. To explore the utilization potential of shallow groundwater and the ...status of water quality pollution in Daqing city, factor analysis and Kriging spatial interpolation methods were applied to analyze the spatial distribution characteristics of pollution sources. The results showed that the HCO
3
-Ca + Mg type water with a maximum salinity of 1.5 g/L was the main chemical type of shallow groundwater in this area. Based on the Fe pollution index, the shallow underground water quality in the northeast of Daqing city can be used for drinking. Due to higher salinity, the locations of the availability of groundwater for irrigation only were in the west. Multivariate statistical analysis was carried out using a factor analysis method, and eight main impact factors were extracted in the study. The pollution sources of human activity impact factors were mainly found to be the direct discharge of organic matter from industrial wastewater in petrochemical enterprises and domestic sewage and the inappropriate or excessive application of agricultural fertilizers. The primary geological environment factors were mainly affected by the hydrogeological and runoff conditions in the study area. Pollution factors were mainly distributed in the northeast of the study area where the pollution was a serious problem, while those in the south-central area were fewer and the pollution was light. This study provides a scientific decision basis for the application of groundwater and the management of groundwater resources in this area.
Graphical abstract
The groundwater vulnerability assessment has been identified as an important tool of groundwater pollution prevention. In this study, the DRASTIC method was modified to estimate the groundwater ...vulnerability of porous aquifers to nitrate. The parameter system was optimized by replacing the original parameters of aquifer media, soil media, impact of the vadose zone and hydraulic conductivity with quantitative parameters of aquifer thickness, nitrate attenuation intensity, hydraulic resistance and groundwater velocity and adding pollutant input intensity to develop the DRANTHVP method. In addition, the rating scale of the DRASTIC method was revised, and the weight and influence degree of each parameter were determined using the projection pursuit dynamic clustering (PPDC) model. The DRANTHVP method was applied to the plain area of western Jilin Province, and the vulnerability index map of groundwater to nitrate pollution was established. The DRANTHVP method improved the correlation coefficient between vulnerability index and nitrate concentration to 0.720, which was more than three times that of the original DRASTIC method. And the high variance of the (ANOVA) F statistic indicated that there was less overlap between the nitrate values in different vulnerability classes. Furthermore, the DRANTHVP method produced a more uniform distribution of vulnerability classes. In short, the DRANTHVP method using the PPDC model was suitable to assess the groundwater vulnerability of porous aquifers to nitrate in the study area. Hence, the mapping of groundwater vulnerability to nitrate can provide a scientific and reasonable basis for the formulation of groundwater resource protection plan.
•The DRANTHVP method was developed based on DRASTIC method modified to assess groundwater vulnerability to nitrate.•The parameter system was optimized by quantitative parameters.•The weight and influence degree of each parameter were determined using the PPDC model.•The correlation with nitrate concentration was more than three times higher than DRASTIC method.
Access to safe drinking water is one of the fundamental human rights and an important part of healthy living. This study considered various land use methods, used geostatistical analysis, and ...triangular random model to explore nitrogen pollution and estimate its potential risk to human health for local populations in Songnen Plain of Northeast China and recognize parameter uncertainties. Nitrate concentrations in groundwater ranged from 0.01 to 523.45 mg/L, more than 72.35% of the samples exceeded Grade III threshold (20 mg/L of N) as per China's standard, and nitrate nitrogen content is greater than 20 mg/L accounted for around 60% of the research area, mainly distributed in the eastern and central high plain area. The nitrate-nitrogen content of groundwater in the town land was significantly higher than that of agricultural land, and the ammonia nitrogen content was conversely. The townland's risk value was two times that of agricultural land, considering different land use methods would avoid overestimating or underestimating regional risk value. Non-carcinogenic risks (HI) of two land use were above the safety level (i.e., HI > 1), suggesting that groundwater nitrate would have significant health effects on the age groups, and further threaten children. There was a wide range of fluctuations in the uncertainty of nitrogen concentration and model evaluation parameters; triangular random model was more sensitive to data changes, which could reduce the uncertainty. The contribution rate of nitrate-nitrogen concentration to risk was above 90%, which explained the need for random sampling to improve the evaluation results reliability. The findings in this paper will provide new insight for solving uncertainties in water safety management.
•Nitrate-nitrogen content in townland was higher than that of agricultural land.•The townland's risk value was two times that of agricultural land.•Triangular stochastic models would reduce the risk uncertainty.•Nitrate-nitrogen concentration was the most sensitive to risk values.
Floral transition in cereals is a critical phenomenon influenced by exogenous and endogenous signals, determining crop yield and reproduction. Flowering Locus T-like (FT-like) genes encode a mobile ...florigen, the main signaling molecule for flowering. In this study, we characterized two FT-like genes, FTL9 and FTL10, to study their functional diversity in flowering control in rice. We compared independent mutant lines of ftl10 with WT and observed negligible differences in the flowering phenotype, or agronomic traits implying potentially redundant roles of FTL10 loss-of-function in flowering control in rice. Nevertheless, we found that overexpression of FTL10, but not FTL9, substantially accelerated flowering, indicating the flowering-promoting role of FTL10 and the divergent functions between FTL9 and FTL10 in flowering. Besides flowering, additive agronomic roles were observed for FTL10-OE regulating the number of effective panicles per plant, the number of primary branches per panicle, and spikelets per panicle without regulating seed size. Mechanistically, our Y2H and BiFC analyses demonstrate that FTL10, in contrast to FTL9, can interact with FD1 and GF14c, forming a flowering activation complex and thereby regulating flowering. Altogether, our results elucidate the regulatory roles of FTL9 and FTL10 in flowering control, unveiling the molecular basis of functional divergence between FTL10 and FTL9, which provides mechanistic insights into shaping the dynamics of flowering time regulation in rice.
To more accurately predict the migration behavior of pollutants in porous media, we conduct laboratory scale experiments and model simulation. Aniline (AN) is used in one-dimensional soil column ...experiments designed under various media and hydrodynamic conditions. The advection-dispersion equation (ADE) and the continuous-time random walk (CTRW) were used to simulate the breakthrough curves (BTCs) of the solute transport. The results show that the media and hydrodynamic conditions are two important factors affecting solute transport and are related to the degree of non-Fickian transport. The simulation results show that CTRW can more effectively describe the non-Fickian phenomenon in the solute transport process than ADE. The sensitive parameter in the CTRW simulation process is
, which can reflect the degree of non-Fickian diffusion in the solute transport. Understanding the relationship of
with velocity and media particle size is conducive to improving the reactive solute transport model. The results of this study provide a theoretical basis for better prediction of pollutant transport in groundwater.
Dongliao River Basin (DLRB) is facing serious deterioration of water quality impacted by anthropogenic activities. As China attaches increasing importance to environmental protection, many regions ...are trying to reduce water pollution through land use changes. The long-term variations of the nonpoint source (NPS) pollution affected by land use changes in the DLRB have not been previously assessed. In this study, the contributions of land use/land cover (LULC) changes in 1980–2015 to NPS pollution were evaluated by comparing simulations under paired land use scenarios using the Soil and Water Assessment Tool (SWAT). The historical trend and ecological protection scenarios in 2025 were established based on CA–Markov model, and pollution loads in both scenarios were forecasted. Results show that the expansion of dryland and urban areas and the decline in forest and grassland coverage were the major contributors to the increase in NPS pollution in the DLRB. The expansion of paddy field resulted in an increase in actual total phosphorus (TP) but a decrease in total nitrogen (TN). In the historical trend scenario, dryland would decrease by 4.57%. TN and TP loads were 1.40% and 1.45% lower than those in 2015, respectively. In the ecological protection scenario, TN and TP loads were 3.37% and 6.11% lower than those in 2015, respectively, due to the decreased area of dryland by 7.22%. Pollutions in the riverside and southeast areas of the basin would be reduced in 2025. This finding shows that NPS pollution is controlled under the current policy.
* A model coupling water-heat-salt of unsaturated frozen soil was established. * Future temperature, precipitation, and evaporation increase in freeze-thaw period. * Soil water, heat, and salt ...transport are closely coupled during freeze-thaw period. * Freeze-thaw cycles and future climate change can exacerbate salinization.
The transport mechanisms of water, heat, and salt in unsaturated frozen soil, as well as its response to future climate change are in urgent need of study. In this study, western Jilin Province in north-eastern China was studied to produce a model of coupled water-heat-salt in unsaturated frozen soil using CoupModel. The water, heat, and salt dynamics of unsaturated frozen soil under three representative concentration pathway (RCP) scenarios were simulated to analyze the effects of future climate change on unsaturated frozen soil. The results show that water, heat, and salt migration are tightly coupled, and the soil salt concentration in the surface layer (10 cm) exhibits explosive growth after freezing and thawing. The future (2020-2099) meteorological factors in the study area were predicted using the Statistical Downscaling Model (SDSM). For RCP2.6, RCP4.5, and RCP8.5 scenarios, future temperatures during the freeze-thaw period increased by 2.68°C, 3.18°C, and 4.28°C, respectively; precipitation increased by 30.28 mm, 28.41 mm, and 32.17 mm, respectively; and evaporation increased by 93.57 mm, 106.95 mm, and 130.57 mm, respectively. Climate change will shorten the freeze-thaw period, advance the soil melting time from April to March, and enhance water and salt transport. Compared to the baseline period (1961-2005), future soil salt concentrations at 10 cm increased by 1547.54 mg/L, 1762.86 mg/L, and 1713.66 mg/L under RCP2.6, RCP4.5, and RCP8.5, respectively. The explosive salt accumulation is more obvious. Effective measures should be taken to prevent the salinization of unsaturated frozen soils and address climate change.
Freeze–thaw cycles (FTCs) occur during the nongrowing season, and residual nitrogen (N) increases the risk of N loss with melting water. To study the effect of FTCs on soil N, rice fields in improved ...irrigated saline soil in northeast China were selected as the research subjects. Water content (10%, 20%, and 30%), different N fertilizer levels (180 and 220 kg/ha), and multiple FTCs of soil samples were used to clarify the effects of N fertilizer application and water content on N efficiency. The results indicate that, after the third FTC, the soil ammonium nitrogen (NH4+-N) level increased significantly. NH4+-N increased with an increase in the initial soil moisture content and decreased with fertilizer levels. Nitrate nitrogen (NO3−-N) decreases with increasing initial soil moisture. The inorganic N increased significantly compared with that in the unfrozen stage, indicating that FTCs promote soil N mineralization. However, high fertilization rates inhibit mineralization. Analysis of variance showed that NO3−-N is sensitive to the N application rate, water content, and salinity (p < 0.05). FTCs and artificial fertilization are the factors that affect N mineralization (p < 0.05). The research results are significant for preventing nitrate leaching and soil acidification during spring plowing and providing a scientific basis for fertilization systems and water environment pollution in improved saline soils.
Changbai Mountain area is an important mineral water storage and development area in China. The hydrochemical composition of mineral water is the decisive factor for mineral–water quality. Based on ...the hydrochemical data of 74 mineral water samples collected from 2018 to 2020, the characteristics and formation mechanism of the hydrochemical components of the mineral water were analyzed. The results show that the formation of single-type mineral springs (metasilicate mineral water) is controlled by rock weathering; compound mineral springs (metasilicate mineral water with high CO
2
content) are the product of CO
2
-rich, weakly acidic, confined hot groundwater with high salinity, which are mixed with shallow groundwater as rising along the fracture. The volcanic geological process greatly influences the formation of the hydrochemical components of mineral springs on the North slope of Changbai Mountain. The mineral springs on the Longgang Mountain are greatly affected by human activities. The results of cluster analysis only consider that hydrochemical components are consistent with the classification of the areas which concentrated distributions of mineral as determined by hydrogeological and geomorphological studies. The results of this study are useful for understanding the distribution, hydrochemical characteristics, and formation mechanism of mineral springs in the Changbai Mountain area of China and provide the theoretical basis for the protection and development of mineral spring.
Road dust, which contains trace elements and certain organic matter that can be harmful to human health, plays an important role in atmospheric pollution. In this paper, concentrations of 16 elements ...in the road dust of Changchun, China were determined experimentally. A total of 100 samples were collected using plastic brushes and dustpans, and the elements were analyzed by an inductively coupled plasma optical emission spectrometer (ICP-OES). It was indicated that the elements could be divided into major and trace elements. The concentration of trace elements followed the trend: mercury (Hg) > manganese (Mn) > zinc (Zn) > lead (Pb) > chromium (Cr) > copper (Cu) > vanadium (V) > arsenic (As) > nickel (Ni) > cobalt (Co) > cadmium (Cd). Contamination-level-assessment calculated by the geo-accumulation index (I
) showed that the pollution-level ranged from non-contaminated to extreme contamination, while the calculations of enrichment factor (EF) showed that EF values exhibited a decreasing trend: Cd > Hg > As > Pb > Cu > Co > Zn > Ni > Cr > V > Mn > Mg > Fe > Sr > Ba. In our study, ingestion was the greatest exposure pathway for humans to intake trace elements by calculating the average daily dose (ADD) from three routes (ingestion, inhalation, and dermal contact). According to the health risk assessment results, the non-carcinogenic risks that human beings suffered from these elements were insignificant. Additionally, the hazard quotient (HQ) values were approximately one-tenth in the case of children. Meanwhile, the total excess cancer risk (ECR) was also lower than the acceptable level (10
⁻10
) for both adults and children.
PDF
