Jialu River Research Articles

Deciphering Microbial Assembly and Coexistence in Rivers Subjected to Long-Term Reclaimed Water Replenishment

Reclaimed water recharge into rivers is an important supplementary approach to address water resource shortage in arid and semi-arid areas worldwide. However, the ecology impacts of reclaimed water recharge on the rivers are still unknown, especially for the microbial assemble and species coexistence in different seasons. Here, the evolution of microbiome and its response to different reasons in the Jialu River, which was subjected to long-term reclaimed water recharge, is investigated by using 16S rRNA gene sequencing and multivariate statistical methods. The results indicated that microbial communities exhibited significant temporal heterogeneity across different periods and were negatively correlated with river discharge. Their assembly was primarily influenced by stochastic processes such as dispersal limitation and drift. As the transition occurred from the dry season to the normal season, the role of drift diminished, while the deterministic effects of dispersal limitation and niche selection intensified. The relationships among planktonic bacterial species were primarily positive (cooperative), and the complexity and positive correlations within the ecological network showed a trend of first decreasing and then increasing with the change of seasons. Temperature, dissolved oxygen, and ammonia nitrogen were the main driving forces influencing the structure of microbial communities. In summary, these findings provided insights into the impact of seasonal variations on the microbial community patterns in reclaimed water-supplemented river ecosystems.

Analysis of the evolution and causes of groundwater chemistry after ecological water replenishment of the Jialu River, China

Ecological water replenishment is an important measure for conserving water sources and improving the water environment. To explore the evolution and causes of groundwater chemistry after ecological water replenishment in the Jialu River, this study utilized groundwater monitoring data from 2015 to 2019 following ecological water replenishment. Various methods, including Piper’s trilinear diagram, Gibbs diagram, principal component analysis, and ion ratio analysis, were employed for research purposes. The results indicate that (1) since the implementation of ecological water replenishment in the Jialu River, there has been a general downwards trend in total dissolved solids (TDS) in groundwater. The dominant cation in groundwater is Ca2+, whereas HCO3− is the dominant anion. The concentration of cations in groundwater has generally decreased, with noticeable reductions in SO42− and Cl− concentrations in the upper reaches of the recharge river contributing to improved groundwater quality. (2) A comparison with 2015 reveals a gradual transition at sampling points from chemical types such as HCO3-Ca·Mg and HCO3·Cl–Ca·Mg to an ecological water replenishment chemical type (HCO3-Ca).

Variation of runoff-sediment relationship at flood event scale in three typical watersheds of the Loess Plateau

River runoff and sediment load are characterized by topography, climate patterns, and vegetation in the watershed. The relationship runoff and sediment load has been greatly altered in many rivers throughout the world, as well as rivers in the Chinese Loess Plateau (LP) due to large-scale ecological restoration and soil conservation measures implementation. This study attempts to identify the changes of runoff-sediment relationship in three watersheds: the Gushanchuan River watershed, Jialu River watershed and Xichuan River watershed by using the flood event data during the periods of 1974–1989 and 2007–2019 in the LP. The results indicated that both runoff depth and sediment yield of flood events during 2007–2019 reduced significantly compared with those during 1974–1989 in all the watersheds. The highest decrease was found in the Gushanchuan River watershed, exhibiting reduction of 56.48% and 95.03% in runoff and sediment yield, respectively. The ratios between sediment yield and runoff depth in all three watersheds showed significant decrease during 2007–2019 when comparing to those in 1974–1989. The correlations between runoff and sediment variables became worse in 2007–2019, compared with those during 1974–1989. The implementation of soil and water conservation (SWC) measures (vegetation restoration, terraces and check dams) accounted for the changes in runoff-sediment relationship in all three watersheds. The result of this study could provide valuable information for the influences of SWC implementation and guide soil erosion control in the LP.

Urban rivers health assessment based on the concept of resilience using improved FCM-EWM-MABAC model

Urban rivers are vital for urbanization and regional economic development, which can provide water for living, industrial and agricultural needs of urban residents, and regulate the hydrological environment in the urban. The exploration of urban rivers health based on resilience theory can provide important reference for urban rivers restoration and resilience urban construction. To this purpose, this study explores the health status of Jialu River during 2011–2020 from the perspective of resilience. First, a comprehensive indicator system based on the resilience theory was established for the health analysis of urban rivers. Second, an urban rivers resilience index (URRI) was developed utilizing the improved FCM-EWM-MABAC method to accurately illuminate the health states of urban rivers. Final, the health state of Jialu River from 2011 to 2022 was diagnosed using the comprehensive indicator system and URRI. Our results suggested that the Jialu River’s health state showed a rapid improvement trend from ordinary state in 2011 to good state in 2020. The health status of resistance, recovery and adaptability subsystems displayed different degrees of improvement during the study period, and the growth trend of adaptability subsystem was the most obvious. Over the past decade, the resilience state of Jialu River had improved by implementing a series of governance measures, but there is still room for improvement. This study can provide significant references for future work on the water resource conservation and sustainable development in rapidly economic developing regions.

Where military and fluvial geographies disastrously conjoined: The Huayuankou flood of 1938–1947 during the Sino-Japanese war

The Huayuankou flood event (1938–1947) refers to the prolonged flooding caused by the artificial bursting of the Yellow River embankment at Huayuankou during the Sino-Japanese War (1937–1945). It recreated the historical scenes of frequent floods in the lower Yellow River region of China since the Ming and Qing Dynasties (1368–1911), with the counties along the Jialu River in the eastern plains of Henan especially becoming the disaster-stricken areas. The flood lasted for nearly nine years until the completion of embankment restoration work in 1947, causing long-term and extensive environmental impacts. This paper discusses this catastrophic historical flood event caused by human factors, the warfare strategies and hydraulic technology that acted as drives, and the location factors and historical context leading to the start of flooding in flood-prone areas of Henan. Based on spatial perspectives and the historical GIS approach, the paper compiles and integrates historical documents and maps with archival material and topographic maps from the 1930s and 1940s to present the extent of the flood, the associated disasters, and the persistent effects of official relief strategies and political situation in the wider context, examining how the Huayuankou flood was used as a military tactic, but with unpredictable disastrous consequences.

Experimental study on prefabricated composite box girder bridge with corrugated steel webs

An innovative prefabricated composite box girder with corrugated steel web was proposed in this paper. This study investigated the mechanical property of the prefabricated composite box girder with corrugated steel web during two batches of tensioning of internal prestressed tendons and one field static loading test at the Jialu River Bridge in Zhengzhou, China. By analyzing the experimental, theoretical and numerical results, a finite element model was established, and the prestress transfer mechanism of the prefabricated composite box girder with corrugated steel web was revealed. The results showed that during tensioning, the prestress of the concrete floor could be effectively transferred to the concrete roof through the coordinated deformation of the web while the sheer force of the section was mainly transferred by the corrugated steel web. The concrete roof was gradually compressed, and upward deflection occurred during the tensioning. The deflection of the test beam was relatively small under the seven types of working conditions, and the deformation of the concrete roof and floor of each section satisfied the plane-section assumption. The normal stress values of the wet joint and prefabricated section of the concrete floor were consistent and changed synchronously, which demonstrates the integrality of the wet joint and prefabricated part of the beam. The test results presented in this study may provide a reference for the design and construction of such bridges.

“The 20 July 2021 Major Flood Event” in Greater Zhengzhou, China: A Case Study of Flooding Severity and Landscape Characteristics

Climate change and rapid urbanization are two global processes that have significantly aggravated natural disasters, such as drought and flooding. Urbanization without resilient and sustainable planning and execution could lead to undesirable changes in landscapes and stormwater regulation capacity. These changes have exacerbated the effects of extreme climatic events with disastrous consequences in many cities worldwide. Unfortunately, the major storm in Zhengzhou, China on 20 July 2021 was one of these examples. This event provided a rare opportunity to study the key roles of green infrastructures (GI) in mitigating flooding risks in a major urban center after a devasting flood event. Using the data from high-resolution images collected via two satellites, a comprehensive study of the Jialu System in Greater Zhengzhou was conducted to systematically compare how far the river water had reached before and after the 20 July 2021 major storm in order to identify the main weak links in the city’s GI and stormwater management system. A flood inundation intensity index (FI) in the Upper (UJLR), Middle (MJLR), and Lower (LJLR) Regions of the Jialu River System was generated. Bivariate Moran’s I, a correlation coefficient between FI and landscape characteristics, was calculated and used to identify problem areas for future improvements. Our results showed that the MJLR had the severest flooding impacts. LJLR had the biggest change in how far the river water reached after flooding, ranging from 4.59 m to 706.28 m. In UJLR, the percentages of mine, crop land, and green space had the highest global bivariate Moran’s I correlation coefficients. In MJLR, the percentages of vacant land, impervious surfaces, and water body had the highest global bivariate Moran’s I correlation coefficients. In LJLR, the percentages of vacant land, water body, and crop land had the highest global bivariate Moran’s I correlation coefficients. The total percentages of both high landscape characteristics indices-high flood inundation intensity indices and low landscape characteristics indices-high flood inundation intensity indices areas are 12.96%, 13.47%, and 13.80% in UJLR, MJLR, and LJLR, respectively. These land cover composition types identified for each region can be treated as areas of primary focus. However, GeoDector Model (GDM) analyses showed that our eight variables of landscape characteristics were not independent. Hence, a more comprehensive approach integrating all eight variables is still necessary in future flood mitigation efforts.

Frequency Analysis of the Nonstationary Annual Runoff Series Using the Mechanism-Based Reconstruction Method

Due to climate change and human activities, the statistical characteristics of annual runoff series of many rivers around the world exhibit complex nonstationary changes, which seriously impact the frequency analysis of annual runoff and are thus becoming a hotspot of research. A variety of nonstationary frequency analysis methods has been proposed by many scholars, but their reliability and accuracy in practical application are still controversial. The recently proposed Mechanism-based Reconstruction (Me-RS) method is a method to deal with nonstationary changes in hydrological series, which solves the frequency analysis problem of the nonstationary hydrological series by transforming nonstationary series into stationary Me-RS series. Based on the Me-RS method, a calculation method of design annual runoff under the nonstationary conditions is proposed in this paper and applied to the Jialu River Basin (JRB) in northern Shaanxi, China. From the aspects of rationality and uncertainty, the calculated design value of annual runoff is analyzed and evaluated. Then, compared with the design values calculated by traditional frequency analysis method regardless of whether the sample series is stationary, the correctness of the Me-RS theory and its application reliability is demonstrated. The results show that calculation of design annual runoff based on the Me-RS method is not only scientific in theory, but also the obtained design values are relatively consistent with the characteristics of the river basin, and the uncertainty is obviously smaller. Therefore, the Me-RS provides an effective tool for annual runoff frequency analysis under nonstationary conditions.

Water-sediment synergistic relationship in the flood season in the coarse sand source regions of the loess plateau, China

A number of studies have been conducted to determine the relationships between runoff and sediment under different conditions. However, the water-sediment synergistic relationship, which refers to the degree of intervention between the runoff and suspended sediment transport processes in the flood season, must be further analyzed. This study proposed the concept of the synergy degree between water and sediment based on the discipline of synergetics created by Haken (Haken, 1983). The flood and suspended sediment transport processes in the flood season and the measured water-sediment coordination levels were adopted in this study to obtain their synergy degree by taking as an example the largest and most continuous region from the Huangfu River to the Jialu River in the coarse sand source regions of the Loess Plateau. The results of this investigation are as follows. The degree of synergy between runoff and suspended sediment transport was below 0.722 from 1958 to 2016. Approximately 70% of the flood events in the five river basins had poor degrees of synergy between the flow and sediment processes in the flood season. Moreover, the synergy degrees of the water-sediment relationship were relatively low in the runoff and suspended sediment transport processes in the flood season due to the low order degrees of these two process subsystems. The low synergistic relationship between these two subsystems shows that the coordination and buffering abilities between the flood and suspended sediment transport processes were weak. These findings demonstrate the successful adoption of synergetics to ascertain the water-sediment synergistic relationship and also provided critical information for designing water conveyance systems with high sediment concentrations for irrigation in the coarse sand source regions of the Loess Plateau, China.

Spatiotemporal Dynamics of Green Infrastructure in an Agricultural Peri-Urban Area: A Case Study of Baisha District in Zhengzhou, China

Quantifying the dynamics of green infrastructure (GI) in agricultural peri-urban areas is of great significance to the regional ecological security, food security, and the sustainable development of urban integration. Based on remote sensing images, this study aims to provide a spatiotemporal dynamic assessment of the GI in Baisha District from 2007 to 2018 to improve the layout of GI and planning policies from the perspective of ecological security and food security. Research methods include landscape pattern indices, spatial autocorrelations, and grid analyses in this case study. The results suggest that ensuring the dominant position of farmland is critical to maintaining the composition and connectivity of the overall GI. The recreation, inheritance of farming culture, and ecosystem service functions of farmland should be improved to meet the growing needs of urban residents. GI includes the farmland, greenspace, and wetland on both sides of the Jialu River that should be retained and restored as much as possible to protect natural ecological processes. Simultaneously, construction of important urban facilities and residential areas in flooded areas should be banned. A part of the evenly distributed large greenspace patches should be moved to both sides of the Jialu River to increase the agglomeration effect of GI. Optimization measures in this case study also offer a perspective for other agricultural peri-urban areas that have experienced similar urbanization.

Soil phosphorus composition, loss risk and contribution to the aquatic environment in a typical agricultural area

Abstract River eutrophication risk increased significantly in agricultural areas. In this paper, spatial variability of soil phosphorus (P) and loss risk in the Jialu River Basin, China, were analyzed using a geostatistical approach. The correlation between soil and river sediment P was analyzed to identify the main aquatic P source. The results showed that inorganic phosphorus (IP) was the main form of soil TP (82.13%), but the ratio of apatite phosphorus (AP) and non-apatite phosphorus (NAIP) varied between different soil types. AP was the primary form of IP in fluvo-aquic cinnamon soil, while NAIP dominated in meadow aeolian sandy soil. Calculated soil total dissolvable P (TDP, 94–622 mg/kg) exceeded the environmental threshold. High TDP (>400 mg/kg) in mixed soil and sandy soil indicated a high P loss risk. The spatial variability of soil P was moderate to weak, indicating a low heterogeneity. In sediment, IP and AP showed a significant correlation with total organic carbon (p < 0.05), indicating a P source of soil erosion. Sediment AP had a significant positive correlation with soil AP (p < 0.05), confirming soil as the main source of sediment P. Furthermore, an accumulation of sediment P along the Jialu River and its consistency with water TP was revealed.

Multi-scale flood prediction based on GM (1,2)-fuzzy weighted Markov and wavelet analysis

Abstract In order to forecast flood accurately and reveal the relationship between rainstorm and flood at the micro level, a model which combines wavelet analysis, GM (1,2) and fuzzy weighted Markov is built. Taking the Jialu River of Zhengzhou City in China as study area, the GM (1,2) model is constructed between the components of rainfall and flood volume by wavelet decomposition to connect the two variables, then a fuzzy weighted Markov method is introduced to correct the predicted component of flood volume. The corrected results are superimposed to obtain the predicted value of flood. To verify the reliability of the model, the maximum daily, 3-, 5- and 7-day flood volume of the next five floods in Zhongmu and Jiangang hydrological stations are predicted in turn. The results show that the multi-scale flood forecasting model has high overall forecasting accuracy, with the average relative errors all less than 10%. The forecasting accuracy of maximum five-day flood volume is higher than other periods. On the micro level, the results indicate that the fluctuation trend and period of rainfall-flood volume in d1, d2 and d3 are basically the same. Among the components of forecasted flood, the impact of rainfall on flood volume is most significant in the d3 component.

Exploring the Dominant Runoff Processes in Two Typical Basins of the Yellow River, China

Storm runoff in basins is comprised of various runoff processes with widely disparate infiltration and storage capacities, such as Hortonian overland flow (HOF), saturated overland flow (SOF), sub-surface flow (SSF), and deep percolation (DP). Areas may be classified according to these various runoff processes based on the soil characteristics, geology, topography, and land-use. This study analyzes changes in runoff components in the Jialu River basin and the Fen River (Jingle sub-basin) during runoff generation from 1980 to 2013 using the runoff segmentation method. Based on the decision scheme, the dominant runoff process (DRP) in the basins was distinguished using geographic information system (GIS) tools. The impact of different runoff process distributions on the changes in the runoff for the basin was determined. The results show that the floods in the Jialu River basin and Jingle sub-basin were dominated by overland flow components. Compared with 1980–1999, the proportion of overland flow components for 2000–2013 in two basins showed a decreasing trend by 8.3% and 7.1%, respectively, while the interflow and underground runoff components increased. In addition, HOF was the DRP in the Jialu River basin and Jingle sub-basin from 2000 to 2013. The area of the rapid runoff processes (HOF, SOF1, and SSF1) in the Jialu River basin and Jingle sub-basin accounted for 89% and 78% of the entire basin, respectively. In contrast, the slow runoff processes (SOF2, SSF2, and DP) accounted for 11% and 22% of the entire basin, respectively. The runoff of the Jingle sub-basin was substantially lower than that of the Jialu River basin under the same rainfall conditions, because of the influence of the distribution of different runoff processes. Compared with the Jialu River Basin, the peak discharge and runoff of Jingle sub-basin were 190.4 m3/s and 2.85 mm lower on average, respectively. The results of this study provide useful information to understand land-use changes and formulate management practices to reduce flooding in the Yellow River.

Insights onto Hydrologic and Hydro-Chemical Processes of Riparian Groundwater Using Environmental Tracers in the Highly Disturbed Shaying River Basin, China

Understanding the hydrologic and hydrochemistry processes in the riparian area is of great importance for managing and protecting riparian water resources. This paper took a highly disturbed and polluted Shaying River Basin (SRB) of China as the study area. In this research, environmental tracers (hydrochemical and isotopic data of222Rn, δ18O, and δD) and corresponding models (two-component mixing model and 222Rn mass balance model) were employed to investigate the hydrologic and associated hydro-chemical process of riparian groundwater. The results indicated that rivers received groundwater discharge located at Xihua (J8), Zhoukou (Y1), Luohe (S2), and Shenqiu (SY2), and the mixing extent with groundwater was greater in wet seasons than in dry seasons. The 222Rn mass balance model showed that the flux of river water leakage was 3.27 × 10−4 m3/(s·m) at the front of Zhoukou sluice while groundwater discharge was 3.50 × 10−3 m3/(s·m) at the front of Shenqiu sluice during the sampling period. The cation exchange and the dissolution/precipitation of aquifer minerals (including calcite, dolomite, gypsum, and halite) were dominated by geochemical processes. The untreated sewage discharge and fertilizer usage were the main anthropogenic activities affecting the hydrochemistry process in surface water and riparian groundwater. Additionally, our results found that nitrate pollutants derived by riparian groundwater were potential threats to river quality at the lower reaches of Jialu River and Shenqiu county of Shaying River, where the nitrate inputs could be larger during the wet seasons because of higher groundwater discharge.

Ecological improvement by restoration on the Jialu River: water quality, species richness and distribution

The Jialu River has experienced serious water quality deterioration and biodiversity decline. An ecological restoration project was undertaken. We investigated water quality, species richness and distribution before and after restoration to describe ecological improvements on the Jialu River. After the project, total nitrogen (TN), total phosphorus (TP), chemical oxygen demand (COD) and ammonium nitrogen (NH4+-N) decreased by 38.69, 40.52, 39.06 and 45.07% respectively. Concentrations of these indices were maintained at steady levels after restoration, indicating stable purification capacity had been established. However, TN, TP and NH4+-N concentrations were still higher than Level V of the Chinese surface water standards. In all, 155 species, belonging to 94 families, were found, with shore plants accounting for the largest proportion (26.53%). The biota showed different distribution patterns over space and time, except for species of zooplankton and phytoplankton, which were evenly distributed over space and time. Most species (71.71%) occurred in only one or two sites. Compared with July 2013, by July 2015 species richness had increased, on average, 65.61%. Furthermore, 31 novel native species were found in July 2015, covering the main functional groups (hydrophytes, zoobenthos and fishes). The recovery of an intact food chain as a result of the project facilitated water purification in the short term and the return of birds to the Jialu River in the long term. This study evaluated the recovery of the Jialu River and the results will inform future ecosystem restoration projects.

Urban River Health Analysis of the Jialu River in Zhengzhou City Using the Improved Fuzzy Matter-Element Extension Model

Urban rivers are valuable elements of urban ecosystems and play a key role in urban socio-economic development. Unfortunately, the functional integrity of urban rivers is being threatened by extensive human activities associated with the social development. Urban river health evaluation is important, as it may provide policy makers with information that is fundamental for river governance and the protection of urban ecosystems. To this purpose, we first constructed an urban river health assessment index system based on the pressure–state–response (PSR) framework. Secondly, we developed an urban river health index (uRHI) using the improved fuzzy matter–element extension assessment model. Finally, we used the uRHI to assess the health state of the Jialu River from 2008 to 2017 in Zhengzhou City, China. The results indicate that the health state of the Jialu River was improved from an unhealthy state in 2008 to a sub-healthy state in 2017. The pressure, state, and response subsystems developed towards a healthier state from 2008 to 2017, thanks to the implementation of a number of actions by the local government. However, the overall health status of the Jialu River is still relatively low. The Jialu River also faces several pressures, such as substantial Chemical Oxygen Demand (COD) emissions and sewage discharge. This paper concludes that it is necessary to further strengthen the health management of the Jialu River and the protection of Zhengzhou’s water environment.

Sources and transformations of anthropogenic nitrogen in the highly disturbed Huai River Basin, Eastern China.

Due to serious nitrogen pollution in the Huai River, Eastern China, nitrogenous concentrations and dual stable isotopes (δ15N and δ18O) were measured to ascertain the sources and transformation of nitrogen in the Shaying River, the largest and most polluted tributary of the Huai River during the summer and winter seasons. Total nitrogen (TN), NO3-, and NH4+ were significantly higher in winter, with values of 7.84 ± 3.44mgL-1, 2.31 ± 0.81mgL-1, and 3.00 ± 2.24mgL-1, respectively, while the highest nitrogen compounds occurred in the Jialu River, one of the tributaries of the Shaying River, in both summer and winter. Isotope characteristics of nitrate reveal that manure and sewage were the principal nitrate sources in both summer (62.44 ± 19.66%) and winter (67.33 ± 15.45%), followed by soil organic nitrogen, with 24.94 ± 15.52% in summer and 26.33 ± 9.45% in winter. Values of δ15N-suspended particulate nitrogen (SPN) ranged from 0.78 to 13.51%, revealing that point source from industrial and domestic sewage accounted for the largest input to SPN at most sites, whereas soil organic nitrogen and agricultural fertilizers were found in the Jialu River in both sampling periods. Point sources from septic/manure and household waste were the main contributors to ammonium in most river water samples in both summer and winter; most wastewater discharged into the river was untreated, which was one of the main reasons for the high level of ammonium in winter. Nitrogen pollution and the dams had an effect on N transformation in the river. Significant assimilation of NH4+ and aerobic denitrification competed for NH4+, resulting in the weakness of nitrification in the summer. Denitrification was also an important process of nitrate removal during the summer, whereas nitrification was a key N transformation process in the river in the winter time. To reduce nitrogen pollution and improve water quality, greater effort should be focused on the management of sources from urban input as well as on the improvement in sewage treatment.

Changing properties and causes of the annual maximum flood in the Jialu River Basin

Based on the daily precipitation data from 1969 to 2015 and the flood summary data of the hydrological station in the Jialu River Basin, the annual maximum flood (AMAXF) and extreme precipitation were used to analyze the changing properties and causes of the annual maximum flood. Mann-Kendall test were used to analyze the change characteristics and the correlations between AMAXF and extreme precipitation were analyzed with cross wavelet analysis method. The changes in the NDVI were also analyzed to investigate the reasons for the changes of AMAXF. The results showed that AMAXF series had a significant decreasing trend with an abrupt change point around 1998, and there was no significant change in extreme precipitation. Cross Wavelet Analysis showed the AMAXF had statistically correlations with extreme precipitation in the Jialu River Basin. The decreasing trend in the AMAXF were mainly caused by LUCC.

The '333' integrated strategy for effective pollution control and its application to the heavily polluted Jialu River in north China.

In this study, an integrated approach named the '333' strategy was applied to pollution control in the Jialu River, in northern China, which is heavily burdened with anthropogenic pollution. Due to a deficiency of the natural ecological inflow, the Jialu River receives predominantly industrial and municipal effluent. The '333' strategy is composed of three steps of pollution control including industrial point-source pollution control, advanced treatment of municipal wastewater, and ecological restoration; three increased stringency emission standards; and three stages of reclamation. Phase 1 of the '333' strategy focuses on industrial point-source pollution control; phase 2 aims to harness municipal wastewater and minimize sewage effluents using novel techniques for advanced water purification; phase 3 of the '333' strategy focuses on the further purification of effluents flowing into Jialu River with the employment of an engineering-based ecological restoration project. The application of the '333' strategy resulted in the development of novel techniques for water purification including modified magnetic resins (NDMP resin), a two-stage internal circulation anaerobic reactor (IC reactor) and an ecological restoration system. The results indicate that water quality in the river was significantly improved, with increased concentrations of dissolved oxygen (DO), as well as reduction of COD by 42.8% and NH3-N by 61.4%. In addition, it was observed that the total population of phytoplankton in treated river water notably increased from only one prior to restoration to 8 following restoration. This system also provides a tool for pollution control of other similar industrial and anthropogenic source polluted rivers.

Assessment of the cytotoxic and mutagenic potential of the Jialu River and adjacent groundwater using human-hamster hybrid cells

The Jialu River in China has been seriously polluted by the direct discharge of industrial and domestic wastewater. The predominant contaminants of the Jialu River and its adjacent groundwater were recently investigated. However, the potential genotoxic impact of polluted water on human health remains to be clarified. Here, we used human–hamster hybrid (AL) cells, which are sensitive for detecting environmental mutagens. We found that the cytotoxicity and mutagenicity of the groundwater in the Jialu River basin were influenced by the infiltration of the Jialu River. Hydrological periods significantly affected the cytotoxicity, but not the mutagenic potential, of surface and groundwater. Further, the mutagenic potential of groundwater samples located <1km from the Jialu River (SM-2 water samples) was detected earlier than that of groundwater samples located approximately 20km from the Jialu River (SN water samples). Because of high cytotoxicity, the mutagenic potential of water samples from the Jialu River (SM-1 water samples) was not significantly enhanced compared with that of untreated controls. To further assess the mutagenic dispersion potential, an artificial neural network model was adopted. The results showed that the highest mutagenic potential of groundwater was observed approximately 10km from the Jialu River. Although further investigation of mutagenic spatial dispersion is required, our data are significant for advancing our understanding of the origin, dispersion, and biological effects of water samples from polluted areas.