Main Source Of Water Research Articles

COMPARISON OF MICROBIOLOGICAL WATER QUALITY ASSESSMENT BETWEEN THE INDIGENOUS PEOPLE AND VISITORS WATER ACTIVITIES IN ROYAL BELUM STATE PARK

The waters within the Royal Belum State Park are predominantly utilized for recreational activities and are the main source of water for indigenous tribes. Changes in population density, tourism and climate changes may impact water quality and the consequences to human and ecological health are of economic and social importance. An assessment of water quality in Temenggor Lake, Royal Belum State Park has been conducted at two sampling locations, namely visitor water activity areas (fishing, swimming, canoeing) and indigenous people water activity areas (dishes washing, laundry, open bathing) to determine and compare the microbiological and physicochemical parameters and to classify the safety of water usage based on the National Water Quality Standards classification for water activity use with body contact. Six locations were selected and analysed in-situ for temperature, dissolved oxygen, pH level and turbidity while total suspended solids, biochemical oxygen demand, ammoniacal-nitrogen, total coliform, enterococci and Escherichia coli were analysed in the laboratory. Results indicated that all physicochemical parameters (temperature, turbidity, total suspended solids, dissolved oxygen and biochemical oxygen demand) except pH and ammoniacal-nitrogen at the six samplings stations were within the acceptable range for water activity use. All stations were within class I to IIB for microbiological parameters in comparison to the National Water Quality Standards classification for Malaysia. This indicates that the waters were safe for water activity with body contact. Visitor water activity areas were safe and clean compared to indigenous people’s water activity areas and the differences were statistically significant. There is modest and visual evidence that the indigenous community may further reduce the water quality in their areas based on their daily sanitation practises of dishwashing and open defecation on land. Hence, the responsibility falls on the authorities to provide a good sewage management system and treated water at the indigenous people’s settlement to protect the lake water quality from deteriorating in the future and contributing to the adverse health effects of its users.

ECOTOURISM MANAGEMENT BASED ON LOCAL WISDOM FOR OPTIMIZING THE FUNCTION OF CAVE WATER RESOURCES AS A PREVENTION OF FLOODS AND DROUGHTS IN WAKATOBI REGENCY, INDONESIA

The basis of local wisdom is an effort to preserve the environment in line with the main goal of developing ecotourism. Successful ecotourism management can optimize the function of the existence of natural resources. The purpose of this study was to examine the local wisdom of the community in ecotourism management to optimize the function of cave water as a prevention of flooding and drought in urban strategic areas. The research method uses descriptive qualitative by digging information through in-depth interviews with traditional leaders, relevant government, community and visitors to water caves. SWOT analysis in this study is used to determine the management of water resources and to plan the development of sustainable ecotourism as an alternative to managing the potential and conservation of cave water. Checking the validity of the data using a triagulation model. The results of the study show that there are three forms of community local wisdom regarding cave water conservation, namely: (1) Ufe Karia, (2) Imaeka, and (3) Sala piara (mistake of care). Should either intentionally or unintentionally have disturbed the existence of cave water. The cave water functions as a natural infiltration well that is able to accommodate large amounts of rain water with a concentrated flow pattern at the cave water point. Meanwhile, other cave water points are the main raw water sources to meet the domestic needs of the community with stable water discharge and never dry. The results of the SWOT analysis show that cave water has the potential to be developed into ecotourism so conserve water resources as a prevention of floods and droughts on Wangi-Wangi Island.

On the sustainability of paddy rice cultivation in the Paraíba do Sul river basin (Brazil) under a changing climate

Located in Southeast Brazil, the Paraíba do Sul River Basin is considered one of the most strategic in the country since it is the main source of fresh water for more than 14.3 million people. The population growth in recent decades, in combination with increased demand for water for industrial and agricultural activities, has generated concerns about how the combined effect of land uses and global climate change might affect water availability in the future. Once irrigation is one of the main water consumers, especially for paddy rice cultivation, in this study we used a crop simulation model to determine the water requirements of paddy rice under current and future climate conditions based on three different regionalized climate scenarios and for different land use and land cover change projections. In addition, we estimated water footprints for different irrigation and soil fertility strategies. Finally, we explored adaptation actions that can lead to more sustainable production. Projections indicate an increase in the productivity and efficiency of irrigated rice. Intermittent flooding proved to be an efficient alternative, rather than the traditional practice of continuous ponding. Most scenarios projected a gradual decrease in water footprint for rice cultivated using irrigation and soil fertility management. On the other hand, the water footprint under rainfed and non-optimum soil fertility resulted in higher water footprints. Due to changes in land use and land cover, mainly urban sprawl, the rice areas are expected to decrease in the future reducing the production in the region, which is expected to decrease by almost 10% in the period 2016–2035 and up to 38% in the period 2036–2055. This trend can be compensated by adopting sustainable practices in rice cultivation, such as rational soil fertility and water management, which can boost the current level of productivity by 50% and reduce water use by up to 15%.

Aquatic landscape and the emergence of walled sites in late Neolithic Central Plains of China: Integrating archaeological and geoarchaeological evidence from the Guchengzhai site

The emergence of many late-Neolithic and early Bronze-Age walled sites on China's Central Plains coincided with some prominent Holocene climate events. Recent excavation and geoarchaeological investigation at one of the largest walled sites of Guchengzhai provide important data to examine some of the questions concerning the long-term relationship between the formation of aquatic landscape and social evolution in late prehistoric Central Plains. We collected fine-grained paleo-environmental and archaeological evidence from a range of on- and off-site contexts to reconstruct the late-Holocene paleo-environment surrounding the walled site, and examine the construction, maintenance and abandonment processes of its large-size moat. Our results show that there existed many small-to-large-sized waterbodies during the late Holocene, which, together with local rivers, were the main source of water to the site. The Guchengzhai population was drawn to the low-lying land near the river and other waterbodies with an optimal hydrological condition. During its use, the moat might have been linked to the nearby wetlands and/or rivers. The hydrological regime was dominated by gentle but relatively sediment-laden flow, being punctuated by several high-energy flood events. The sedimentation of light yellowish silt and sand with some anthropogenic inclusions during the use of the moat gave way to a quick siltation with the deposition of rich organic matter when the moat ceased to function as a main channel for water flow, although other land-use activities such as fire (land clearance?) continued to occur in the vicinity. The reconstructed ‘life-history’ of the moat demonstrates the increasingly acute challenge facing the growing population living at Guchengzhai as the climate was becoming drier. The construction and operation of the moat signified technological innovations and intensified water management at Guchengzhai, which led to the formation of distinctive aquatic landscape that featured large-scale hydraulic infrastructures in a hydrologically optimal environment. We contend that such was a common characteristic or trend shared by many contemporary or later-period walled sites on the Central Plains.

Documentary Film Creation “Impact of Kanta River Water Pollution on Conditions Social Economic Citizens Around The Estuary of Drainage”

The Kanta River flows in Pujon District and Ngantang District. This river water is used for irrigation, livestock sanitation, and the main source of water for hydropower plants and tourist water sources of the Selorejo Reservoir. The high role of this river water is apparently not realized so that residents use the Sunga Kanta watershed as a place to dispose of garbage and sewage. The current water condition of the Kanta River is quite poor and the settlement around the Selorejo Reservoir as a drainage estuary is the most affected area. The author responds to this water pollution problem in a film with the title "The Impact of Canta River Water Pollution on the Socioeconomic Conditions of Residents Around the Drainage Estuary". The documentary genre is an option because according to the character of this film, which presents facts according to reality, it is actually considered capable of accommodating the message of the film. The film narrative is prepared based on research data that has been analyzed descriptively and obtained by three data collection methods which include observation, literature study, and interviews. Films are shown publicly so that the message of the film can be widely accepted by citizens. In the end, this documentary is expected to be able to give birth to awareness to jointly maintain the water ecosystem, especially rivers.

The surface energy balance during foehn events at Joyce Glacier, McMurdo Dry Valleys, Antarctica

Abstract. The McMurdo Dry Valleys (MDV) are a polar desert, where glacial melt is the main source of water to streams and the ecosystem. Summer air temperatures are typically close to zero, and therefore foehn events can have a large impact on the meltwater production. A 14-month record of automatic weather station (AWS) data on Joyce Glacier is used to force a 1D surface energy balance model to study the impact of foehn events on the energy balance. AWS data and output of the Antarctic Mesoscale Prediction System (AMPS) on a 1.7 km grid are used to detect foehn events at the AWS site. Foehn events at Joyce Glacier occur under the presence of cyclones over the Ross Sea. The location of Joyce Glacier on the leeward side of the Royal Society Range during these synoptic events causes foehn warming through isentropic drawdown. This mechanism differs from the foehn warming through gap flow that was earlier found for other regions in the MDV and highlights the complex interaction of synoptic flow with local topography of the MDV. Shortwave radiation is the primary control on melt at Joyce Glacier, and melt often occurs with subzero air temperatures. During foehn events, melt rates are enhanced, contributing to 23 % of the total annual melt. Foehn winds cause a switch from a diurnal stability regime in the atmospheric surface layer to a continuous energy input from sensible heat flux throughout the day. The sensible heating during foehn, through an increase in turbulent mixing resulting from gustier and warmer wind conditions, is largely compensated for by extra heat losses through sublimation. Melt rates are enhanced through an additional energy surplus from a reduced albedo during foehn.

Hydro-chemical characterisation and quality assessment of shallow groundwater in parts of the Kathmandu Valley, Nepal

Groundwater is the main source of water for drinking and irrigation in the Kathmandu Valley of Nepal. Although quality of groundwater is crucial for public health, there is little information available. Considering this, groundwater samples were collected during the post-monsoon and winter from 35 dug wells of Lalitpur Metropolitan City located in the Kathmandu Valley. Chemical analysis of these samples has revealed alkaline nature of groundwater. Factor analysis (FA) and correlation analysis (CoA) have identified lithology, geogenic, and anthropogenic activities as the main factors governing groundwater chemistry. Cluster Analysis (CA) segregated samples into five clusters indicating difference in their hydrochemistry. The Weightage Arithmetic Water Quality Index (WAWQI) has revealed unsuitability of groundwater for drinking. Among the chemical constituents, Fe, Ca2+, Mg2+ and PO43− are found most influential. Concentration of iron, and calcium were much higher than the recommended limit for drinking water. High total coliform (TC) content in particular makes groundwater of the valley totally unsafe for drinking. While percentage of sodium (Na%), sodium adsorption ration (SAR), and salinity hazard values of the samples are found suitable, on the basis of the Permeability Index (PI), several winter and post-monsoon samples were unsuitable for irrigation. This study strongly recommends for treatment and purification of groundwater before supply and use for drinking and irrigation purposes to minimise health-risk.

Analysis of Groundwater Flows under the Fukushima Daiichi Nuclear Power Plant Reactors Using Contaminated Water from 42 Subdrain Pits

We analyzed groundwater collected from 42 subdrain pits (wells) located around the reactor buildings of plant units #1 to #4 of the Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Plant (F1-NPP) to understand the groundwater dynamics and water flows around F1-NPP. Since water samples collected from this small area exhibit very similar water quality, there are difficulties in understanding the flow dynamics of the groundwater using conventional chemical analyses. In this study, we clarified the groundwater flows using an altitude-modified principal component analysis (PCA) with a total of 798 data items (19 factors × 42 pits) in the chemical analyses. The PCA results showed that six specific pits deviated from the common values and that the others contained contributions from both the natural elements and radioactive nuclides. The groundwater flows under units #1–#4 into two flow lines originating from two main water sources were classified, and these lines merged around the bayside of unit #2 due to the lower groundwater head. This method proved suitable for elucidating the groundwater dynamics and water flows in this small area by the proposed altitude-modified PCA.

Historic Variability of the Water Inflow to the Lazaro Cardenas Dam and Water Allocation in the Irrigation District 017, Comarca Lagunera, Mexico

An assemblage of tree-ring chronologies for the Nazas (NZW) in the Western Sierra Madre (WSM), Mexico was developed to determine water inflow at the Lazaro Cardenas Dam (LCD), the main source of water for surface irrigation in the Irrigation District 017 (DDR 017), Comarca Lagunera. A Principal Component Analysis of the ring-width chronologies was conducted to determine a common climate signal, and a stepwise model based on selected chronologies of the PC1 (CBA, COC) and PC2 (ARN) were used to develop a water inflow reconstruction to the Lazaro Cardenas Dam (LCD) extending from 1753 to 2003 (251 years), resulting in the following significant findings: the warm phase of the El Niño Southern Oscillation (ENSO) in the winter-spring season had a significant influence (SOI; Dec–Feb = −0.24, p < 0.01), but the North American Monsoon System (NAMS) was the most important in determining the water yield in the summer season (r = 0.48, p < 0.01). Water gauge inflow records (77 years) at the LCD used to determine the annual allocation of water for agriculture in the irrigation district 017 was an average of 1676 × 106 m3, where the maximum annual water outflow allowed of 1100 × 106 m3 for safety reasons, the dam infrastructure was released in 74% of the years and increasing to 78% when considering the reconstructed inflow. Prolonged drought episodes lasting more than 10 consecutive years were detected in the reconstructed inflow, information that could be used by decision makers to establish proper irrigation management strategies to ameliorate the economic and social impact when these extreme hydroclimatic events may occur.

Efeitos da poda no desenvolvimento vegetativo e qualidade da biomassa de halófitas perenes cultivadas em aquaponia salina

ABSTRACT The cultivation of vascular plants in aquaculture is becoming increasingly important and saline aquaponics have been centered on plants with a short life cycle (i.e. annual species). However, the cultivation of perennial halophytes can allow to produce biomass year-round by repeated cuttings and regrowth. The present study evaluated the effects of different cutting regimes on the growth and tissue nitrogen uptake of the perennial halophyte Paspalum vaginatum and Salicornia neei cultivated in saline aquaponics. Clarified water from Litopenaeus vannamei cultivation was used as the main source of water and nutrients to grow plants established in Nutrient Film Technique (NFT). In each trial (28 days), three groups of 22 plants were established in different NFT benches and subjected to no cutting, one harvest and two harvests. Cutting regimes applied to both halophytic species did not affect the quality of recirculating water. Tillering and stem elongation of P. vaginatum had increasing trends with augment of cutting frequency. Salicornia neei cut at 28-day intervals produced a larger number of marketable size branches with less lignified shoots than non-cut plants and branchy plants cut every 14 days, which showed the smallest branch size. Individual plants of P. vaginatum and S. neei took up in their tissues between 2.27-2.45 mg/day of N and 4.59-6.43 mg/day of N, respectively. Cutting regimes did not statistically affect the accumulation of nitrogen in the biomass of either halophytic species. One harvest treatment, every 28 days, was considered the most suitable practice for aquaponics production of both halophytes.

사천 선상지 ‘새미’의 이용 실태 및 가치 고찰

This study is about the story of ‘Saemi’, existing in the Sacheon Alluvial fan area. Saemi is a local word for Dumbeong, which is the traditional water irrigation facilities in this area that could be formed according to the geographical characteristics of a Alluvial fan site. In the meantime, although Saemi has been an important source of water, related research has been mainly done from an ecological point of view. Accordingly, the researcher paid attention to the functional aspects of Saemi itself, grasped its location, distribution status, and usage including the construction method, and considered its intrinsic value through classification and characteristic analysis of Saemi. As a result of five field surveys from September 2021 to October 2022, 129 Saemies remained in the Sacheon alluvial fan area. According to the structure and shape, Saemi could be divided into basic type, complex type, and buried type. The basic type was subdivided into bucket-type and stairs-type along with the complex type, and the buried type was subdivided into all buried-type and some buried-type. Saemies were mainly distributed at the distal end of the Sacheon alluvial fan site, individual Saemies were built on farmland, and common Saemies were usually built along roadsides adjacent to villages. The reason why the Saemies are concentrated at the distal end is the geographical characteristics of the alluvial fan where the water underflows. Saemi was an important multifunctional water supply source equivalent to the main water source for people at the distal end of the pond who did not receive a stable supply of water from the reservoir. Saemi was at the center of the underground water irrigation network agricultural system in the Sacheon alluvial fan area according to the principles of ‘bbaeim(drop out)’ and ‘gaepim(pooling)’ It has provided a foundation for establishing itself as an appropriate technology in this area. Such Saemi contributed to the rural landscape and agricultural biodiversity through its own system and served as a public interest function. It is necessary to know, conserve, manage, and continuously utilize the value of this Saemi as an agricultural heritage.

Aggravation of nitrogen losses driven by agriculture and livestock farming development on the Qinghai-Tibet Plateau

Nitrogen (N) losses from crop-livestock production is a major threat to the environment and human health at regional, national and global scales. A comprehensive understanding of the sources, spatiotemporal distribution and drivers of N losses is of great significance for mitigating its negative impacts and promoting N sustainable management. Here, we used the county-scale N flow model to quantitatively analyze the N losses and their driving forces of crop-livestock production on the Qinghai-Tibet Plateau (QTP). Between 2000 and 2018, the total N losses increased for more than 79% of counties on the QTP. The hotspot areas accounted for over 80% of total N losses, expanding from the east and south to the north and west of the QTP. NH3 was the main source of atmospheric N losses (over 80%) while the direct discharge of manure was the main source of water N losses. Structural equation modeling (SEM) showed that chemical fertilizer caused the largest driving effect on atmospheric N losses, and the total output value of agriculture and forestry was the main driver of water N losses. Uneven distribution of crop production and livestock contributed to the aggravation of N losses. Over 70% of counties had grater manure N excretion than crops could take up, and large proportion of manure could not be returned to the field. More than 90% of the counties used grater amount of chemical fertilizer N than crops could take up, indicating that livestock manure has not yet fully replaced chemical fertilizer N. The results provide effective guidance and support for N utilization and management of livestock in agricultural and pastoral areas.

Seasonal variations in water uptake and transpiration for plants in a karst critical zone in China

Despite substantial drought conditions in the karst critical zone (KCZ), the KCZ landscapes are often covered with forest woody plants. However, it is not well understood how these plants balance water supply and demand to survive in such a water-limited environment. This study investigated the water uptake and transpiration relationships of four coexisting woody species in a subtropical karst forest ecosystem using measurements of microclimate, soil moisture, stable isotopes (δ18O, δ2H, and δ13C), intrinsic water-use efficiency (WUEi), sap flow, and rooting depth. The focus was on identifying differences within- and between-species across soil- and rock-dominated habitats (SDH and RDH) during the rainy growing season (September 2017) and dry season (February 2018). Species across both habitats tended to have higher transpiration with lower WUEi during the rainy season and lower transpiration with higher WUEi during the dry season. Compared to those in the SDH, species in the RDH showed lower transpiration with higher WUEi in both seasons. The dominant water sources were soil water and rainwater for supporting rainy-season transpiration in the SDH and RDH, respectively, and groundwater was the main water source for supporting dry-season transpiration in both habitats. A clear ecohydrological niche differentiation was also revealed among species. Across both habitats, shallower-rooted species with higher soil-water uptake, compared to deeper-rooted species with higher groundwater uptake, showed higher transpiration and lower WUEi during the rainy season and vice versa during the dry season. This study provides integrated insights into how forest woody plants in the KCZ regulate transpiration and WUEi in response to drought stress through interactions with seasonal water sources in the environment.

Numerical study on flow pattern in meandering channels: The effect of hydraulic conditions and meander geometry

Natural rivers are one of the main sources of water and energy for humans. The design and management of exploitation of natural rivers systems will require a complete understanding of flow and sediment transport mechanics. Meanders are one of the most common types of rivers in nature, which have a very complex flow. The three-dimensional (3D) and complex characteristics of flow in meanderings bring up the necessity of investigating the flow pattern in this channel with 3D numerical models. This study aimed to investigate the flow pattern and predict the erosion and sedimentation site in the meandering. Also, the effect of the Froude number (Fr), the ratio of width-to-depth ([Formula: see text]/[Formula: see text] and meander angle parameters on the flow field are investigated. In this study, the turbulent flow pattern in a sine-generated channel and the angle of 50∘ with a rectangular section with width = 40 cm and the rigid bed is studied using the 3D mathematical model SSIIM1.1. The primary and secondary flow patterns were studied using the turbulence models of [Formula: see text]-[Formula: see text] and SST [Formula: see text]-[Formula: see text]. Comparison of numerical models and experimental results showed that the flow pattern is predicted well by both turbulence models of turbulence. But in some cases, the SST [Formula: see text]-[Formula: see text] model has provided closer results to the experimental results. The results show that the shear stress pattern depends on the changes in the Fr. But, the secondary flow pattern does not change much by changing the Fr. Also, changes in the [Formula: see text]/[Formula: see text] ratio affect the secondary flow pattern and shear stress pattern, so that for [Formula: see text]/[Formula: see text], a small rotary cell is made in addition to the main rotary cell near the outer coast. The results also show that the flow pattern and shear stress depend on the channel angle.

Water-use characteristics of two dominant plant species in different community types in the Mu Us Desert

Shrubs are pioneer species for ecological restoration in drylands and can promote the growth of herbaceous plants. Knowledge of the water-use characteristics of these revegetated species in different community types is crucial for understanding interspecific and intraspecific interactions and guiding ecological restoration; however, few studies have focused on this process. In this study, we explored the water sources and root distribution of plants in three community types in the Mu Us Desert: a mixed community including a shrub species Artemisia ordosica and a grass species Leymus secalinus, a pure A. ordosica community, and a pure L. secalinus community. We measured the δ18O of the plant xylem and soil water within 100 cm of the soil surface and surveyed the root biomass distribution. The main water source for both A. ordosica and L. secalinus in mixed communities was from the shallow soil layer (0–20 cm) and it overlapped most of the time. When soil moisture in the shallow soil layer was low, L. secalinus still used water from the shallow soil layer, whereas A. ordosica mainly used water from the dry deep soil layer (60–100 cm). The water sources for A. ordosica were significantly different among different communities. In contrast, L. secalinus had similar water sources in different communities. We also found that the root biomass of shrubs was significantly lower in mixed communities than in pure communities. Moreover, when available soil water increased, the root biomass of grasses increased significantly, whereas that of shrubs did not significantly change. These results suggest grasses have an advantage over shrubs in competing for water and this may lead to the exclusion of shrubs from the community, and grasses dominated community. Our study can be used as a reference for assessing the persistence of shrub species to guide future ecological restoration.

Natural Zeolite for The Purification of Saline Groundwater and Irrigation Potential Analysis.

Groundwater is one of the main sources of water for irrigation used worldwide. However, the application of the resource is threatened by the possibility of high saline levels, especially in low-lying coastal regions. Furthermore, the lack of readily accessible materials for successful treatment procedures makes the purification of such water a constant challenge. Based on the fact that natural zeolite is one of the easily accessible and relatively cheap filter materials, this study examined the potential use of high-salinity groundwater filtered by natural zeolite for irrigation. Zeolite-filled filters at two different depths (0.5 m and 1 m) were studied. The samples were collected from the low-lying areas of Dar es Salaam City, Tanzania. The study observed that when the raw groundwater samples were exposed to the 0.5 m column depth, sodium (Na+) had the lowest removal efficiency at 40.2% and calcium (Ca2+) had the highest removal efficiency at 98.9%. On the other hand, magnesium (Mg2+) had the lowest removal efficiency, at about 61.2%, whereas potassium (K+) had up to about 99.7% removal efficiency from the 1 m column depth treatment system. Additionally, from the salinity hazard potential analysis, most of the samples fell within C4 (based on the electrical conductivity), which is a "very high salinity" class, and based on the quality it means the water cannot be directly applied for irrigation purposes. From the 0.5 m column depth, most of the samples fell within C3 (the "high salinity" class), and from the 1 m column depth most of the samples fell within C1 ("low salinity" class). The findings of this study offer some valuable insight into the prospective use of natural zeolite for the filtration of saline groundwater before its application for irrigation.

Assessment of extraneous water inflow in separate sewerage system by different quantitative methods

Extraneous water that inflow to the sewage system is basically divided into two streams—accidental water (mainly rainwater) and infiltration water. The aim of the research was to assess the amount of extraneous water inflow to the considered system. Five different quantitative approaches were applied. Three well-known methods were used: the triangle method, the minimum night flow method, and the moving minimum method. The annual balance of water consumption and sewage supply to the wastewater treatment plant were calculated. Also, some analysis of sewage discharge during wet and dry weather was carried out. The study covered data from 6 years from 2014 to 2019. It was established that the main source of extraneous water was infiltration, because three methods which concern both streams (triangle method, minimum night flow, variability in wet and dry weather) confirm the conclusion. Merely the moving minimum method results differ from the others. In this investigation, accidental water (basically rainwater inflow) poses a significantly less share in the total volume of sewage compared to infiltration water. The total amount of extraneous water was estimated as in the range from 38 to 53% of annual sewage supply to wastewater treatment plant, depending on the year. Share of infiltration and accidental water is changing in different methods. Share of infiltration was in a range between 18 and 68%, depending on the year and the method used. Share of accidental water was in a range between 7 and 22%.

Achieving the One Health Goal: Highlighting Groundwater Quality and Public Health

In many regions of the world, groundwater is the main water source for multiple uses, including for drinking, irrigation, and industry. Groundwater quality, therefore, is closely related to human health, and the consumption of contaminated groundwater can induce various waterborne diseases. In the last ten years, the world has witnessed a rapid development in groundwater quality research and the assessment of associated health risks. This editorial introduced the foundation of the current Special Issue, Groundwater Quality and Public Health, briefly reviewed recent research advances in groundwater quality and public health research, summarized the main contribution of each published paper, and proposed future research directions that researchers should take into account to achieve the one health goal. It is suggested that groundwater quality protection should be further emphasized to achieve the one health goal and the UN’s SDGs. Modern technologies should be continuously developed to remediate and control groundwater pollution, which is a major constrain in the development of a sustainable society.

Potable Water Security in Rural South Africa: A Case Study of Vhembe District

South Africa is a semi-arid country and has limited water resources. The provision of potable water to rural communities remains a challenge. The current study assesses the provision of water services and community’s perceptions of water supply amid the coronavirus pandemic in Vhembe District Municipality (VDM). A sample of 448 households was selected from 14 villages. Findings revealed that communities rely on a variety of water sources with the main water source being boreholes. Households spend a significant amount of time daily to fetch water. Of the 38 boreholes in the villages, only 28% are functional and water tankers are used in times of emergency, most of which are also unreliable. The respondents were not satisfied with the quantity, quality of the water, distance travelled and reliability of the service. Water provision in VDM remains a challenge and thus needs immediate intervention particularly in the light of curbing the spread of the coronavirus. Keywords: Access to Water, Reliable Potable Water, Community’s Perceptions, Rural Communities, Water Service Provision

Synergistic improvement of nitrogen and phosphorus removal in constructed wetlands by the addition of solid iron substrates and ferrous irons

Sanjiang Plain is intensively used for rice production, and ditch drainage diffuse pollution prevention is crucial. Groundwater, rich in Fe ions, is the main source of irrigation water in this region. In this study, pyrite and zero-valent iron (ZVI) (sponge iron and iron scraps) were used as substrates to identify the synergistic influence of exogenous Fe2+addition and solid iron substrates on pollutant removal in constructed wetlands. Based on the results, iron substrates hardly improved the ammonia removal, mainly because of the physical structure and oxidation activity. At a hydraulic retention time longer than 8 h, the pollution removal efficiency in the zero-valent iron (ZVI) substrate treatment increased significantly, and the removal of nitrate (NO3−-N) and total phosphorus (TP) in the iron scrap substrate treatment reached about 60% and 70%, respectively. The high-throughput sequencing results showed a significant increase in the abundance of microorganisms involved in denitrification and phosphate accumulation in biofilms on ZVI substrates. The highest diversities of such microorganisms in biofilms on iron scraps were found for denitrifying bacteria (Pseudomonas), nitrate-reducing Fe (II)-oxidizing bacteria (Acidovorax), and Dechloromonas with autotrophic denitrification and phosphate accumulation, with a 43% cumulative abundance. Dechloromonas dominated in the iron sponge substrate treatment. The highest relative abundance of Acidovorax was found in the mixed iron substrate (pyrite, sponge iron, and iron scraps) treatment. The addition of ZVI substrate significantly improved the removal of NO3−-N and TP and reduced the hydraulic retention time through the continuous release of Fe2+ and the promotion of microbial growth. When designing constructed wetlands for treating paddy field drainage, the appropriate addition of iron scrap substrates is recommended to enhance the pollutant removal efficiency and shock load resistance of CWs.