Urban River Water Quality Research Articles

Assessment of Urban River Water Quality Using Modified NSF Water Quality Index Model at Siliguri City, West Bengal, India

Assessment of Urban River Water Quality Using Modified NSF Water Quality Index Model at Siliguri City, West Bengal, India

Immobilization of microorganisms in activated zeolite beads and alkaline pretreated straws for ammonium-nitrogen removal from urban river water

AbstractThe non-treated wastewater from residential areas contains high concentrations of ammonium-nitrogen (NH4+-N). When discharged into the drainage water system, it deteriorates the water quality in urban rivers. This study used two types of materials to form eco-bags, using activated zeolite bead (AZB) and alkaline pretreated straw (APS), in geotextile bags for easy recovery and reuse. The AZB and APS provided the breeding habitat for the microorganisms that promoted biofilm formation on their surface. The immobilization of engineered denitrification microorganisms facilitated the removal of NH4+-N from the urban river water. The NH4+-N removal in the AZB and APS bags were in the range of 64–73%, and 56–61%, respectively, while the chemical oxygen demand (COD) removal in the AZB and APS bags ranged from 33–36%, and 30–31%, respectively. In addition, as evident from DNA and microbial community analysis, the microorganisms demonstrated a greater proclivity to grow and proliferate on the surface of AZB and APS and improved the water quality of urban rivers.

Ecological assessment of water quality in an urban river replenished with reclaimed water: the phytoplankton functional groups approach

Comprehensive water quality assessment plays a vital role in decision making for the sustainable management of urban rivers, and thus the exploration of integrated ecological assessment methods for water quality has become a major requirement. This study assessed the water quality of the North Canal River on the basis of its ecological status using the phytoplankton functional groups (PFGs) approach. The river runs through the megacities of the Beijing-Tianjin-Hebei region in China, and is mainly replenished with reclaimed water. The results showed that the PFGs approach is much better for evaluating the water quality of urban rivers than the conventional physicochemical index method and phytoplankton diversity metrics, because the PFGs approach is more sensitive to the spatiotemporal variations in the water quality of urban rivers. The average Q r index, for ecological status estimation in rivers, based on the PFGs of the North Canal River was 3.30, indicating ‘good’ water quality. In the dry season, the dominant PFG upstream was group D (Cyclotella spp.), whereas the major downstream PFGs had changed to group Y (Glenodinium spp., Cryptomonas ovata, and Cryptomonas erosa) and W1 (Euglena spp. and Gonium pectoral). While the dominant PFG throughout the river changed to TB: Melosira spp. in the wet season. The Q r at each site was one to two grades lower during the wet season than the dry season, indicating that water quality was worse in the wet than the dry season.

Urban river water quality improvement in Bandung City, Indonesia

Bandung City is one of the big cities in Indonesia with a relatively poor river water quality. Several improvement efforts have been made, especially by the government. This study aims to review these improvement efforts and the results obtained. The rivers that are the leading review are the Cikapundung River, Citepus River, Cicadas River, and Cipamokolan River. The data was obtained from the monitoring results conducted by the government environmental service bureau of Bandung and the Province of West Java. Based on the study results, it was found that there was an improvement in the water quality of the Citepus River, but this river had a non-biodegradation capacity in 2020. The high TSS, COD, BOD, and MBAS detergents indicate the dominating domestic activity in urban watersheds. The most significant control effort to improve the quality of river water in the city of Bandung is the availability of waste treatment at the source, both household and regional scale. Onsite efforts to improve river water quality also have a positive impact, i.e., applying an eco-enzyme solution and developing structures in the river for the aeration process.

Retrieval of water quality parameters from hyperspectral images using a hybrid feedback deep factorization machine model

Environmental protection of water resources is of critical importance to daily life of human beings. In recent years, monitoring the variation of water quality using remote sensing techniques has become prevalent. Unmanned aerial vehicle (UAV) based remote sensing techniques have been applied to quantitative retrieval of concentrations of water quality parameters including phosphorus, nitrogen, chemical oxygen demand (COD), biochemical oxygen demand (BOD), and chlorophyll a (Chl-a), successfully and efficiently. In this study, a novel method with deep factorization machine, spatial distribution pattern analysis, and probabilistic analysis engaged, named hybrid feedback deep factorization machine (HF-DFM), has been developed to quantitatively estimate concentrations of water quality parameters based on hyperspectral reflectance data on large scale effectively. Our proposed method is a unified model for quantifying concentrations of water quality parameters with an end to end structure, which integrates UAV based optical remote sensing techniques and deep learning to estimate concentrations of water quality parameters. Furthermore, our proposed model was applied to real-time quantitative monitoring the variation of water quality of Mazhou River, Shenzhen, Guangdong, China. Finally, we evaluate the performance of proposed model on a real-world dataset in terms of root of mean squared error (RMSE), mean absolute percent error (MAPE), and coefficient of determination (R2). The experimental results show that our proposed model outperforms other state-of-the-art models with respect to RMSE, MAPE, and R2, where resulting MAPEs for quantifying all water quality parameters range from 8.78% to 12.36%, and resulting R2s range from 0.81 to 0.93. It can serve as a useful tool for decision makers in effectively monitoring water quality of urban rivers.

Changes in turbidity and human activities along Haihe River Basin during lockdown of COVID-19 using satellite data.

During the outbreak of the COVID-19, China implemented an urban lockdown in the first period. These measures not only effectively curbed the spread of the virus but also brought a positive impact on the ecological environment. The water quality of urban inland river has a significant impact on urban ecology and public health. This study uses Sentinel-2 visible and near-infrared band reflectance and the Normalized Difference Turbidity Index (NDTI) to analyze the water quality of the Haihe River Basin during the control period of COVID-19. It is found that during the lockdown period, the river water quality was significantly improved compared to the same period in 2019. The average NDTI of the Haihe River Basin in March decreased by 0.27, a decrease of 219.06%; in April, it increased by 0.07, that is 38.38%. Further exploration using VIIRS lights found that the brightness of the lights in the main urban area was significantly lower in February, the beginning of the lockdown. However, as the city was unblocked, the lights rose sharply in March and then recovered to normal. There is obvious asynchrony in changes between river turbidity and light. The results can help understand the impact of human activities on the natural environment.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11356-021-15928-6.

Influence of reclaimed water on water quality of urban rivers receiving WWTP effluent in Beijing

As a new type of water source, reclaimed water is used to replenish the landscape water bodies of urban river courses, which can alleviate the problem of insufficient water in river courses. However, due to the large amount of reclaimed water input, the water quality of the downstream river is obviously different from that of the upstream river. In this study, with the recharge of reclaimed water, the water conductivity increased gradually from upstream to downstream of the Wenyu River river, while the pH decreased gradually. In terms of nutrient concentration, TN, NO3-N and NO2-N of river water showed an obvious upward trend from upstream to downstream.

Study on effect of different reservoir water diversion modes on river water quality improvement

Urban river water pollution is a serious environmental issue and tends to become worse. One of the key measures to improve urban river water quality is to divert water from upstream reservoir to downstream river course to flush pollutant. In this paper, a one-dimensional hydrodynamic and water quality model of Hun River network was developed based on HEC-RAS model. Different reservoir water diversion modes for sewage discharge were simulated and their effect on the water quality improvement of downstream river course was analysed. The results show that under different diversion flow rates, the larger the diversion flow rate, the better the effect on water quality improvement, and that when total water diversion volume is fixed, the effect of long-term diversion with a low flow rate is better than that of short-term diversion with a high flow rate on downstream water quality improvement. The research results can provide scientific support for optimization of the operation of water diversion from reservoir for sewage discharge.

Sources, transformations of suspended particulate organic matter and their linkage with landscape patterns in the urbanized Beiyun river Watershed of Beijing, China

This study explored the sources, transformations of suspended particulate organic matter (POM), and the influence of landscape patterns on POM within the Beiyun River Watershed by applying the stable carbon and nitrogen isotope technique combined with multiple statistical analyses. The POM variables showed great spatial fluctuations under different urban development gradients. Analysis of multiple isotopes revealed that assimilation of phytoplankton might exist in the rainy season, while nitrification occurs in the dry season. SIAR modeling results indicated that the sewage debris and phytoplankton were the main sources of POM in both seasons, accounting for 52.58% and 38.39% in the rainy season, 33.17% and 31.95% in the dry season, respectively. Spatiotemporal variations of POM sources existed in the study watershed, probably due to urbanization and human disturbance. The multiple linear stepwise regression and redundant analysis results indicated that landscape metrics reflecting contagion and fragmentation at the class level correlated well with the POM variables over seasons. Interspersion and juxtaposition indices of grassland and water were negatively related to POM variables in the rainy season, whereas the landscape division index of buildup land showed negative correlations with POM parameters in the dry season. Increasing the adjacency of grassland and water to other land uses, while reducing the aggregation of buildup lands would be an efficient way for urban river water quality improvement.

Deoxygenation rate coefficient in modeling the quality of urban rivers in Indonesia

This study investigates the use of the deoxygenation rate coefficient in modeling the urban river water quality in Indonesia. The method used in this study is data collection in the form of calculating the rate of deoxygenation carried out in rivers in several urban areas based on previous studies. This assessment includes the amount of deoxygenation rate, calculation, and determination method. Based on the studies conducted, the method recently used is laboratory treatment. Several studies have used an empirical formula proposed by Hydroscience to determine the deoxygenation rate. Most of the deoxygenation rate value determination used the Slope Method, but many also directly referenced typical values without performing analysis in the laboratory. The deoxygenation rate for urban rivers in Indonesia, which has been based on various determination methods, varies from 0.001 per day to more than 1.00 per day. Low deoxygenation rates are often found at sampling sites. This can be caused by pollutants that inhibit the process of decomposing organic matter in river waters. The comparison between the use of laboratory tests and empirical formulas shows a vast difference.

Impact assessment of water diversion project on urban aquatic ecological environment

Water diversion project (WDP) plays an increasingly important role in improving the water quality of urban rivers along the Yangtze Delta megalopolis of China. However, their effects on the water ecological environment has generated extensive debates. Water quality variables and phytoplankton community dynamics were tracked and monitored during the summer–winter water diversions to explore the comprehensive effects of WDP on the urban aquatic ecological environment. The multi-index comprehensive evaluation model (MCEM) was adopted for further quantitative assessment, together with a newly proposed progressive degree calculation model (PDCM), which broke the limitations of the traditional ways using Markov chains. The grade evaluation was based on the Environmental Quality Standards for Surface Water (GB 3838–2002) in China. The comprehensive water quality evaluated by MCEM was improved with the largest improvement of two grades after WDP in summer, which on the contrary was worsened because of water transfers in winter by a maximum decrement of one grade. The PDCM evaluation on water quality index indicated that WDP has improved the water quality to some extent but without grade changes. Also, the proportion of Cyanobacteria and Chlorophyta decreased in the phytoplankton community of the three rivers after WDP, whereas the proportion of Bacillariophyta increased, indicating that the community structure was more inclined to the Yangtze River. The comprehensive water pollution situation evaluated by MCEM was improved with the largest improvement from middle pollution to lower pollution (one grade) because of water transfers. The changes in aquatic biological indexes evaluated by PDCM were more obvious than those of water quality indexes, which were improved by one grade.

An Integrated Device for Online Monitoring Water Quality

For a long time, worsening water pollution has always been an important threat to the safety of water sources in most cities at home and abroad. Statistics show that in recent years, sudden pollution accidents caused by oil spills and toxic chemical leakage have occurred frequently all over the world, causing serious environmental pollution and huge ecological losses. Therefore, there is an urgent need to improve the water quality monitoring of water sources and the early warning and forecasting capabilities of sudden environmental pollution. The urban inland river water quality monitoring system is an application demonstration developed by using Internet of Things technology for urban inland river water quality monitoring and water source security. In this article, we build a real-time monitoring network for inland river water quality monitoring to effectively solve the existing offline water quality monitoring workload and timeliness. Poor performance, water pollution warning and emergency response are slow to ensure the water quality and environmental safety of urban inland rivers.

The effects of surface pollution on urban river water quality under rainfall events in Wuqing district, Tianjin, China

A large quantity of pollutants is washed off by stormwater during rainfall events. Polluted storm runoff deteriorates the water quality of receiving water bodies, which is becoming a main threat to urban water environment. In this work, five rainfall events were monitored to clarify the characteristics of land surface pollution in Wuqing district, China. Four pollutant indicators of storm runoff samples, including chemical oxygen demand (COD), total phosphorus (TP), total nitrogen (TN) and ammonia nitrogen (NH3-N), were analyzed and then used to validate the parameters of a model established by Infoworks integrated catchment modeling (ICM). The land surface pollutant loads of metropolitan area for four different rainfall scenarios and the variations in pollutants concentration in urban rivers were illustrated based on the model. The simulated results showed that the volume of runoff increased from 31.8 × 104 m3 to 139.7 × 104 m3 with the increase in the return period. The EMCs (Event Mean Concentration) of pollutants, however, were negatively correlated with return periods and the maximum drop was approximately 67%. Furthermore, the increased runoff enhanced the dilution effect and reduced the residence time of pollutants in rivers, which were the main reasons for the decrease of the pollutants concentrations. The results suggested that the runoff should be taken into account when considering the effects of surface pollution on urban river water quality.

EVALUATING FUTURE WATER QUALITY OF URBAN RIVERS IN HANOI UNDER EFFECT OF URBANIZATION AND CLIMATE CHANGE - THE APPLICATION OF WEAP MODEL FOR CAU BAY RIVER

Every day, up to 750,000 cubic meters of wastewater in Hanoi metropolitan areas is discharged directly into rivers and lake, of which only 10% is treated to the Vietnamese standards. According to the water drainage development master plan for the capital city of Hanoi until 2030, the government aim at dealing with flooding and improve environmental sanitation for local residents. With respect to the baseline and Master plan implementation scenarios, this study evaluates the future water quality of urban rivers in Hanoi under the effect of urbanization and climate change using Water Evaluation And Planning tool (WEAP) and take the Cau Bay catchment as the case study. The result shows that, without implementation of wastewater treatment plant, the water quality of Cau Bay River will be worse with the DO in dry season is 0.2-1.2 mg/l and BOD is 52.0-55.0 mg/l. With the implementation of Master plan, the level of DO and BOD would be 7.1-7.3 mg/l and 7.0-13.8 mg/l respectively in the dry season whereas the values are 3.7 mgO/l and 36.1-41.8 mg/l in the wet season. The degradation of wastewater during the wet season is results from the combine- overflow sewage system as designed in the master plan.

Impact of intensive land use on heavy metal concentrations and ecological risks in an urbanized river network of Shanghai

• Concentrations and spatial distribution of HMs in the river network were influenced by intensive land use. • AVS and TOC in river sediments influenced the migration and transformation of Cd, Hg and Zn. • Hg and Cd were the main contributors of RI, HMs in the central city area showed the highest potential ecological risk. • HMs in the river network primarily originated from industrial activities, traffic emissions and coal-burning emissions. Heavy metal pollution characteristics in the urbanized river network are closely related to urban land use. The existing studies mainly focused on the pollution characteristics of heavy metals in single rivers, but fewer studies reported the impact of land use on the concentrations and ecological risks of heavy metals in surface water and sediments of the urban river network. This study combined land use types with heavy metal pollution in rivers, and explored the specific impact of intensive land use on the characteristics of heavy metal pollution in rivers, which provided scientific basis for the study of heavy metal pollution in plain river networks. The concentrations, spatial variations and potential ecological risk levels of cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), lead (Pb) and zinc (Zn) in surface water and sediments from five different intensive land use areas of Shanghai river network (industrial areas, agricultural areas, central city, suburban towns and Chongming Island) were analyzed. Results showed the concentrations of Cd, Cr, Cu, Pb and Zn in surface water of the Shanghai river network were relatively low, but Hg pollution existed in some rivers. Influenced by intensive land use, heavy metal concentrations in the central city were generally higher than those in other areas. Heavy metals in sediments had considerable ecological risk, in which Hg and Cd were the main contributors, and showed the highest potential ecological risk in central city. Acid volatile sulfides (AVS) and total organic carbon (TOC) in river sediments affected the migration and transformation of Cd, Hg and Zn. Industrial activities, traffic emissions and coal-burning emissions were the main sources of heavy metals. Intensive land use caused by anthropogenic activities led to the weakening of hydrodynamic conditions and the discharge of a large number of pollutants into the river network. In the central city with intensive anthropogenic activities, heavy metals in the river network showed higher levels than those in other areas. This study found that intensive land use and high-intensity anthropogenic activities led to the high pollution level of heavy metals in the plain urbanized river networks. Quantitative analyses of the effects of intensive land use on heavy metal pollution in urbanized river networks were suggested to conduct further to protect the urban river water quality.

Improved Principal Component-Fuzzy Comprehensive Assessment Coupling Model for Urban River Water Quality: A Case Study in Chongqing, China

An improved principal component-fuzzy comprehensive assessment coupling model for urban river water quality is proposed, which fully considers the influence of water quality and quantity. This model can not only choose the key indexes, but also specify the spatial variation and class of water quality. This proposed model was used to assess the water quality of the Qingshui and Fenghuang streams in Chongqing, China. Data of twelve indexes used in the assessment were collected from 17 monitoring points. The assessment results show that the key indexes include TN, TP, NH3-N, CODcr, pH, DO and velocity. Water quality of 14 monitoring points is classified as class Bad V, and that of the remaining points is class V. Mainly affected by the deposition of garbage and discharge of domestic sewage, water quality of the midstream is the worst. The upstream is mainly influenced by farmland non-point source pollution and rural domestic sewage pollution. The downstream is close to the scenic area, and environmental control measures such as river dredging and artificial aeration are regularly carried out. The water quality of it is the best. The results provide valuable information that allow local environmental departments to discover the source of pollutant and formulate water resource management strategies.

Purification Effect of Sequential Constructed Wetland for the Polluted Water in Urban River

Constructed wetlands can play an active role in improving the water quality of urban rivers. In this study, a sequential series system of the floating-bed constructed wetland (FBCW), horizontal subsurface flow constructed wetland (HSFCW), and surface flow constructed wetland (SFCW) were constructed for the urban river treatment in the cold regions of North China, which gave full play to the combined advantages. In the Yitong River, the designed capacity and the hydraulic loading of the system was 100 m3/d and 0.10 m3/m2d, respectively. The hydraulic retention time was approximately 72 h. The monitoring results, from April to October in 2016, showed the multiple wetland ecosystem could effectively remove chemical oxygen demand (COD), ammonia nitrogen (NH4+-N), total nitrogen (TN), total phosphate (TP), and suspended solids (SS) at average removal rates of 74.79%, 80.90%, 71.12%, 78.44%, and 91.90%, respectively. The removal rate of SS in floating-bed wetland was the largest among all the indicators (80.24%), which could prevent the block of sub-surface flow wetland effectively. The sub-surface flow wetland could remove the NH4-N, TN, and TP effectively, and the contribution rates were 79.20%, 64.64%, and 81.71%, respectively. The surface flow wetland could further purify the TN and the removal rate of TN could reach 23%. The total investment of this ecological engineering was $12,000. The construction cost and the operation cost were $120 and $0.02 per ton of polluted water, which was about 1/3 to 1/5 and 1/6 to 1/3 of the conventional sewage treatment, respectively. The results of this study provide a technical demonstration of the restoration of polluted water in urban rivers in northern China.

Assessment of urban river water quality and developing strategies for phosphate removal from water and wastewaters: Integrated monitoring and mitigation studies

In this work, the water quality status of the surface water that lies around the Karamana River basin, Trivandrum urban area, was studied on the basis of the water quality index (WQI) method. The eutrophic condition of the basin is revealed, and proper mitigation strategy was adopted for the removal of phosphate species using pillared clay materials. Proper sampling was carried out in the urban rivers, and various physico-chemical parameters for evaluating the quality of water were analysed. WQI values obtained for these riverine systems are in the range 317.7–3005.1, indicating that the water is not suitable without treatment for any domestic activities. Also, phosphate ions in the range 1.98–20.52 mg/L reflect the dominance of phosphate species in surface water. A proper mitigation strategy was adopted for the selective removal of phosphate ions using adsorption technique by using zirconium-pillared bentonite clay (ZPBC) prepared by the stirring–ageing technique. The batch adsorption experiment performed on simulated phosphate solution shows that for 2.0 g/L of ZPBC a maximum phosphate adsorption capacity of 35.71 mg/g was achieved in 30 min at pH 3.0. The data obtained were used to study models in kinetics and isotherm. The reusability of spent ZPBC for five continuous cycles without major loss in adsorption capacity using 0.025 M Na2CO3 extractant was proved from the desorption study. A single-stage reactor was also designed from the isotherm data and proved to be effective. The applicability of the adsorbent towards phosphate anions was successfully checked in the laboratory using surface water collected and found that the complete removal of phosphate was achieved using 6.0, 8.0 and 10.0 g/L of ZPBC.

Effects of Landscape Development Intensity on River Water Quality in Urbanized Areas

Urban development and human activities have greatly changed the appearance of urban landscapes, and also affect urban river water environments. Rapidly urbanized regions in China face particularly severe pressures and challenges in alleviating degradation of river water quality. Information is needed on which indexes of landscape development intensity in rapidly-urbanized areas are the key factors affecting the quality of river water environments, and how these factors affect water quality. In order to answer these questions, this research selected six indexes belonging to three dimensions for landscape development intensity evaluation. Based on five water quality parameters of 20 rivers and the land use data of 20 small watersheds of Liangjiang New Area, Chongqing, China in 2014, this research explored the correlation between the landscape development intensity indexes and river water quality through redundancy analysis. We found that the impervious surface rate and the land average fixed asset investment are the key indexes to affect river water quality. Regulating the corresponding indexes at the urban planning and design level, as well as the decision making level, can effectively achieve the goal of improving urban river water quality. The conclusions inspire strategies in planning and design, and are helpful for government decision making to effectively protect river water environment in rapidly urbanized areas in the developing countries.

‘Swimmability’: A key element for communities to safely engage with Australian urban rivers

Australia’s largest cities are growing, and this is placing increasing pressure on urban waterways. There is a growing awareness that the quality of life in Australian urban communities is enhanced through the engagement of people with healthy urban rivers. Swimming, boating, and fishing in many Australian urban waterways are popular recreational activities. Swimming and other activities associated with waterways contributes to quality of life in urban communities. Swimming in urban rivers can be risky. Hazards include dangerous currents, aquatic plants, submerged hazards, algal blooms, and unsuitable water quality. In Sydney, Australia’s largest City, swimming is popular in the Hawkesbury-Nepean River. Data from showed that E. coli levels in the river occasionally exceeded safe recreational guidelines for human health. The results are not reported to the public. We believe that it is more important than ever that government, industry and scientific bodies work to protect and improve the water quality of Australian urban rivers as our cities grow. Sharing this information with the community needs to consider education programs, public forums, and timely communication of the current state of local Australian urban rivers regarding their ‘swimmability’.