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Assessment of Water Quality

A special issue of Water (ISSN 2073-4441). This special issue belongs to the section "Water Quality and Contamination".

Deadline for manuscript submissions: closed (30 September 2021) | Viewed by 71311

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Guest Editor
Institute of Evolution, University of Haifa, Haifa, Israel
Interests: algae; cyanobacteria; ecology; cummunity structure; bioindicators; water quality
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Water quality is currently one of the main indicators of the standard of living; therefore, all developed societies are making maximum efforts to provide the population and the economy with sufficient water of adequate quality. Most of the water comes from natural sources, including rivers, lakes, and reservoirs, the quality of which it is necessary not only to assess but also to predict. Classification systems of water quality, methods for assessment, and presentations of the results can be summarized, improved, and developed. The characteristics of diversity, abundance, biomass, and species composition of aquatic biota are used in bioindicator methods of water quality assessment in changing the environment. They enable an integrated assessment of the results of all processes occurring in a water body.

Prof. Dr. Sophia Barinova
Guest Editor

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Keywords

  • algae
  • invertebrates
  • fish
  • macrophytes
  • diversity
  • bioindicator
  • water quality
  • aquatic ecosystem
  • rivers
  • lakes
  • sea
  • estuary

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Published Papers (15 papers)

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24 pages, 5018 KiB  
Article
Preliminary Assessment of Ecological Status of the Siversky Donets River Basin (Ukraine) Based on Phytoplankton Parameters and Its Verification by Other Biological Data
by Olena Bilous, Sergey Afanasyev, Olena Lietytska, Oksana Manturova, Oleksandr Polishchuk, Inna Nezbrytska, Maryna Pohorielova and Sophia Barinova
Water 2021, 13(23), 3368; https://doi.org/10.3390/w13233368 - 29 Nov 2021
Cited by 7 | Viewed by 3022
Abstract
The river basin of Siversky Donets is of great scientific interest since this river runs through a territory with heavy industry (in particular, coal mining, chemical processing and metal industries). Within the basin, rivers of different sizes were explored (small, medium, large and [...] Read more.
The river basin of Siversky Donets is of great scientific interest since this river runs through a territory with heavy industry (in particular, coal mining, chemical processing and metal industries). Within the basin, rivers of different sizes were explored (small, medium, large and extra-large) that flow through siliceous and calcareous rocks on the same elevation (lowland—below 200 m a.s.l.). Phytoplankton, as one of the Biological Quality Element, was used to perform the assessment of ecological status of the water bodies within the Siversky Donets river basin in 2019. The state monitoring program based on the updated approaches has been implemented in the river basin for the first time. The composition of phytoplankton species in the basin comprised 167 species (168 intraspecies taxa), mainly Bacillariophyta (63%) and Chlorophyta (22%) with the presence of other species (Cyanobacteria, Charophyta, Chrysophyta, Dinophyta and Euglenophyta). High species diversity and divisions amount are a distinctive property of the smaller rivers, while the bigger rivers show lower number of divisions. The “bloom” events, which are important ecological factors, were not detected in the Siversky Donets river basin. Algal species composition in plankton samples of the basin was identified and series of ecological parameters, such as habitat preferences, temperature, pH, salinity, oxygenation and organic water pollution according to Watanabe and Sládeček’s index of saprobity (S) trophic state and nitrogen uptake metabolism were analyzed. The ecological conclusions were also verified by a canonical correspondence analysis (CCA). The significance of the Canonical Correspondence Analysis (CCA) results was estimated of by a Monte-Carlo permutation test. The high concentrations of inorganic phosphorus compounds (permanganate index (CODMn)) and nitrite ions favored the diversity of Chlorophyta and Cyanobacteria diversity correlated with the levels of bicarbonate and CODMn. High diversity of diatoms was facilitated by the total amount of dissolved solids and chemical oxygen demand (COD). It was found that low water quality could be associated with conditions leading to predominant growth of the mentioned groups of algae. According to the analysis, the highest water quality was characterized by balanced phytoplankton composition and optimal values of the environmental variables. The sites with reference conditions are proposed for future monitoring. Full article
(This article belongs to the Special Issue Assessment of Water Quality)
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11 pages, 4775 KiB  
Article
Effect of the COVID-19 Pandemic on Residential Water Use Behavior in Japan
by Kanako Toyosada, Chika Nakagawa, Takehiko Mitsunaga and Hiroyuki Kose
Water 2021, 13(21), 3129; https://doi.org/10.3390/w13213129 - 5 Nov 2021
Cited by 2 | Viewed by 2431
Abstract
To investigate the effect of the COVID-19 (coronavirus) pandemic on residential water use behavior in Japan, we conducted a web-based survey of 1310 people throughout Japan in March 2021, one year after the initial spread of coronavirus. The survey was designed to provide [...] Read more.
To investigate the effect of the COVID-19 (coronavirus) pandemic on residential water use behavior in Japan, we conducted a web-based survey of 1310 people throughout Japan in March 2021, one year after the initial spread of coronavirus. The survey was designed to provide an average picture of Japan. The survey revealed that the time respondents spent at home increased during the pandemic for both men and women in all age groups by an average of 1 h, an increase of 9%. Changes in water use behavior increased almost in proportion to the increase in time spent at home, except for the frequency of defecation, which was limited to once a day. The amount of time spent in the washroom increased by 13%, an increase of more than 1.4 times the increase in the amount of time spent at home. The additional 40% increase could be considered an effect of the awareness of disease prevention. The coronavirus pandemic is expected to end in the near future. In Japan, the pandemic has led to a strong push for the reform of work styles. Therefore, even in a post-coronavirus-pandemic society, changes in work styles may normalize the increased time spent at home and the proportional increase in water use. However, because the change in water use behavior caused by quarantine awareness is a result of the fear of coronavirus infection, it is possible that water use will gradually return to pre-pandemic levels once the source of the fear is removed. To reflect the changes in water use behavior in the design of facilities in the post-coronavirus-pandemic society, it is necessary to continue this survey even once the pandemic has ended. Full article
(This article belongs to the Special Issue Assessment of Water Quality)
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18 pages, 1371 KiB  
Article
The Assessment of Phytoplankton Dynamics in Two Reservoirs in Southern Africa with Special Reference to Water Abstraction for Inter-Basin Transfers and Potable Water Production
by Johannes Sirunda, Paul Oberholster, Gideon Wolfaardt, Marelize Botes and Christoff Truter
Water 2021, 13(21), 3045; https://doi.org/10.3390/w13213045 - 1 Nov 2021
Cited by 6 | Viewed by 2547
Abstract
Toxic phytoplankton in the aquatic ecosystems are dynamic, affecting water quality. It remains unclear as to how possible toxic phytoplankton assemblages vary vertically and temporally in Swakoppoort and Von Bach dams, located in a dry subtropical desert region in central Namibia. The following [...] Read more.
Toxic phytoplankton in the aquatic ecosystems are dynamic, affecting water quality. It remains unclear as to how possible toxic phytoplankton assemblages vary vertically and temporally in Swakoppoort and Von Bach dams, located in a dry subtropical desert region in central Namibia. The following variables were analyzed: pH, Secchi depths, turbidity, water temperature, total phosphorus, orthophosphate, chlorophyll-a, phytoplankton cells, and water depths. Cyanobacteria dominated the phytoplankton community in the autumn, winter and spring (dry) and summer (wet) seasons, at all the depth ranges in both dams. Microcystis dominated the vertical and temporal dynamics, followed by Dolichospermum. In the dry seasons, higher cyanobacteria cell numbers were observed in comparison to the rainy season in both dams. Spring blooms of cyanobacteria were evident in the Von Bach Dam while autumn and spring cyanobacteria blooms were observed in the Swakoppoort Dam. In the Swakoppoort Dam, the preferable depth ranges for toxic cyanobacteria species were at 5 to 10 m while in the Von Bach Dam at 0 to 5 m range. The findings of the current study indicate that the traditional selective withdrawal of water in the two dams should be performed with vertical and temporal dynamics of possible toxic cyanobacteria accounted for to aid the abstraction of water with the lowest possible toxic phytoplankton numbers, which could lower the public health risk. Full article
(This article belongs to the Special Issue Assessment of Water Quality)
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15 pages, 885 KiB  
Article
Evidence of Resistance of Heavy Metals from Bacteria Isolated from Natural Waters of a Mining Area in Mexico
by Alondra Escamilla-Rodríguez, Salvador Carlos-Hernández and Lourdes Díaz-Jiménez
Water 2021, 13(19), 2766; https://doi.org/10.3390/w13192766 - 6 Oct 2021
Cited by 12 | Viewed by 5655
Abstract
This study focuses on identifying relationships between the content of heavy metals in water and the resistance patterns of different bacteria. Samples from watercourses in one of the most important mining areas in Mexico were collected. Seventy-one bacteria were isolated, and their resistance [...] Read more.
This study focuses on identifying relationships between the content of heavy metals in water and the resistance patterns of different bacteria. Samples from watercourses in one of the most important mining areas in Mexico were collected. Seventy-one bacteria were isolated, and their resistance to Cr, Zn, Cu, Ag, Hg, and Co was studied. The Minimum Inhibitory Concentration range was determined, and a Multiple Metal Resistant index was calculated. After that, 11 isolated bacteria were chosen to estimate kinetic parameters. The obtained results show differences in the behavior of the studied bacteria concerning the presence of heavy metals in the media: (1) without effect, (2) inhibited growth; and (3) considerable inhibited growth. Finally, a Performance Index was proposed to select adequate bacteria for heavy metals removal; five bacteria were selected. Among them, Pseudomonas koreensis was identified as a good candidate for a future biosorption system since these bacteria can stimulate growth in the presence of all the metals tested. Full article
(This article belongs to the Special Issue Assessment of Water Quality)
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19 pages, 2924 KiB  
Article
Multi-Scale Analysis of the Dependence of Water Quality on Land Use Using Linear and Mixed Models
by Johann Alexander Vera Mercado and Bernard Engel
Water 2021, 13(19), 2618; https://doi.org/10.3390/w13192618 - 23 Sep 2021
Cited by 4 | Viewed by 2441
Abstract
Land use influences water quality in streams at different spatial scales and varies in time and space. Water quality has long been associated with agricultural and urban land uses in catchments. The effects of developed, forest, pasture, and agricultural land use on nitrogen, [...] Read more.
Land use influences water quality in streams at different spatial scales and varies in time and space. Water quality has long been associated with agricultural and urban land uses in catchments. The effects of developed, forest, pasture, and agricultural land use on nitrogen, nitrate, and nitrite (NNN); total phosphorus (TP); total suspended solids (TSS); chemical oxygen demand (COD); dissolved oxygen (DO) and total Kjeldahl nitrogen (TKN) concentrations and their sensitivity were quantified to spatial pattern differences. The linear mixed modeling framework was used to examine the importance of spatial extent on models with water quality parameters as the response variable and land use types as the predictor variable. The results indicated that land use categories on different water quality parameters were significant and dependent on the selected spatial scales. Land use exhibited a strong association with total phosphorus and total suspended solids for close reach distances. Phosphorus is not highly soluble, and it binds strongly to fine soil particles, which are transported by water via runoff. Nitrogen, nitrate, and nitrite, dissolved oxygen, chemical oxygen demand, and total Kjeldahl nitrogen concentrations were better predicted for further reach distances, such as 45 or 50 km, where the best model of nitrogen, nitrate, and nitrite is consistent with the high mobility of NO3. Full article
(This article belongs to the Special Issue Assessment of Water Quality)
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15 pages, 8958 KiB  
Article
A Gateway to Rapid Prediction of Water Quality: A Case Study in China’s South-to-North Water Diversion Project
by Yuxuan Zhang, Ranhang Zhao, Haofang Wang, Tao Peng and Huaqing Zhao
Water 2021, 13(17), 2407; https://doi.org/10.3390/w13172407 - 1 Sep 2021
Cited by 3 | Viewed by 2997
Abstract
Water quality assurance is the primary factor for the successful operation of water diversion projects across river basins. The rapid prediction of water pollution is the basis for timely and effective emergency control and disposal measures. In China, since the open channels intersect [...] Read more.
Water quality assurance is the primary factor for the successful operation of water diversion projects across river basins. The rapid prediction of water pollution is the basis for timely and effective emergency control and disposal measures. In China, since the open channels intersect with numerous waterways and traffic arteries, water transfer projects are prone to sudden water pollution accidents. In this paper, the rapid prediction method was developed for sudden water pollution accidents that possibly occurred in the East Route of the South-to-North Water Diversion Project (ERP) in Shandong Province. With the empirical formula of the pollution transfer law, a rapid prediction model of water quality (WQRP) was established based on the simulation of the typical accidents in the main channel. Finally, four typical accidents were selected as application examples, and the prediction results were compared with the results from a computer numerical simulation to demonstrate the validity of the model. The results showed that the prediction results by the WQRP model meet the accuracy requirements. This method is of great significance for providing water transport security in the extreme conditions of long-distance water transfer projects. Full article
(This article belongs to the Special Issue Assessment of Water Quality)
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15 pages, 3057 KiB  
Article
The Benthic Trophic Corner Stone Compartment in POPs Transfer from Abiotic Environment to Higher Trophic Levels—Trichoptera and Ephemeroptera Pre-Alert Indicator Role
by Angela Curtean-Bănăduc, Alexandru Burcea, Claudia-Maria Mihuţ and Doru Bănăduc
Water 2021, 13(13), 1778; https://doi.org/10.3390/w13131778 - 27 Jun 2021
Cited by 15 | Viewed by 2569
Abstract
Persistent organic pollutants (POPs) have been at the forefront of environmental contamination research even before their ban in 2001 at the Stockholm Convention. Their relation to different compartments of the environment (biotic and abiotic) has been thoroughly investigated. This article aims to identify [...] Read more.
Persistent organic pollutants (POPs) have been at the forefront of environmental contamination research even before their ban in 2001 at the Stockholm Convention. Their relation to different compartments of the environment (biotic and abiotic) has been thoroughly investigated. This article aims to identify whether the benthos could represent a reliable indicator of environmental contamination with POPs and to highlight its potential transfer role between abiotic and upper trophic compartments—benthos feeders. In this regard, we determined that the Ephemeroptera samples have higher concentrations (p < 0.05) of ΣPCB, ΣHCH, and ΣDDT than sediment samples while Trichoptera samples have higher concentrations (p < 0.05) only in the case of ΣPCB and ΣDDT. This, along with the fact that the frequency of detection for POPs is similar between the sample types (sediments, Trichoptera, and Ephemeroptera), makes the benthos samples valuable indicators of contamination with sediment samples working as complementary information about how recent the contamination is. Full article
(This article belongs to the Special Issue Assessment of Water Quality)
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25 pages, 2571 KiB  
Article
The Role of External Factors in the Variability of the Structure of the Zooplankton Community of Small Lakes (South-East Kazakhstan)
by Moldir Aubakirova, Elena Krupa, Zhanara Mazhibayeva, Kuanysh Isbekov and Saule Assylbekova
Water 2021, 13(7), 962; https://doi.org/10.3390/w13070962 - 31 Mar 2021
Cited by 5 | Viewed by 3013
Abstract
The variability of hydrochemical parameters, the heterogeneity of the habitat, and a low level of anthropogenic impact, create the premises for conserving the high biodiversity of aquatic communities of small water bodies. The study of small water bodies contributes to understanding aquatic organisms’ [...] Read more.
The variability of hydrochemical parameters, the heterogeneity of the habitat, and a low level of anthropogenic impact, create the premises for conserving the high biodiversity of aquatic communities of small water bodies. The study of small water bodies contributes to understanding aquatic organisms’ adaptation to sharp fluctuations in external factors. Studies of biological communities’ response to fluctuations in external factors can be used for bioindication of the ecological state of small water bodies. In this regard, the purpose of the research is to study the structure of zooplankton of small lakes in South-East Kazakhstan in connection with various physicochemical parameters to understand the role of biological variables in assessing the ecological state of aquatic ecosystems. According to hydrochemical data in summer 2019, the nutrient content was relatively high in all studied lakes. A total of 74 species were recorded in phytoplankton. The phytoplankton abundance varied significantly, from 8.5 × 107 to 2.71667 × 109 cells/m3, with a biomass from 0.4 to 15.81 g/m3. Shannon diversity index of phytoplankton in the lakes at high altitude varied from 1.33 to 2.39 and from 0.46 to 3.65 in the lakes at lower altitudes. The average weight of the cells of algae species varied from 0.2079 to 1.5076 × 10−6 mg in the lakes at lower altitudes, the average weight of the cells of algae species changed from 0.6682 to 1.2963 × 10−6 mg in the lakes at higher altitudes. Zooplankton was represented by 58 taxa. The total abundance of zooplankton varied from 0.05 to 169.00 thousand ind./m3 with biomass of 0.51–349.01 mg/m3. Shannon diversity of zooplankton in the lakes at lower altitude fluctuated from 0.42 to 2.32 and it was 0.66–1.77 in the lakes at higher altitudes. The average individual mass of specimens in zooplankton in mountain lakes ranged from 0.021 to 0.037 mg and varied from 0.002 to 0.007 mg in other lakes. The main factors in the development of the structure of zooplankton communities in small lakes were temperature, TDS, the content of nitrates, phosphates, and the composition and biomass of planktonic algae. The hydrochemical and biological data of the investigated lakes indicated their organic pollution. Our results once again confirmed the applicability of structural variables of zooplankton in assessing water quality. Full article
(This article belongs to the Special Issue Assessment of Water Quality)
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22 pages, 32556 KiB  
Article
Fecal Contamination and High Nutrient Levels Pollute the Watersheds of Wujiang, China
by Raju Sekar, Xin Jin, Shuang Liu, Jing Lu, Jianwei Shen, Yingya Zhou, Ziyang Gong, Xueying Feng, Shengjie Guo and Wenlong Li
Water 2021, 13(4), 457; https://doi.org/10.3390/w13040457 - 10 Feb 2021
Cited by 4 | Viewed by 4110
Abstract
Freshwaters in China are affected by point and non-point sources of pollution. The Wujiang District (Suzhou City, China) has a long history of canals, rivers, and lakes that are currently facing various water quality issues. In this study, the water quality of four [...] Read more.
Freshwaters in China are affected by point and non-point sources of pollution. The Wujiang District (Suzhou City, China) has a long history of canals, rivers, and lakes that are currently facing various water quality issues. In this study, the water quality of four rivers and a lake in Wujiang was assessed to quantify pollution and explore its causes. Seventy-five monthly samples were collected from these water bodies (five locations/samples per area) from August to October 2020 and were compared with nine control samples collected from a water protection area. Fifteen physicochemical, microbiological, and molecular–microbiological parameters were analyzed, including nutrients, total and fecal coliforms, and fecal markers. Significant monthly variation was observed for most parameters at all areas. Total phosphorus, phosphates, total nitrogen, ammonium–nitrogen, and fecal coliforms mostly exceeded the acceptable limits set by the Chinese Ministry of Environmental Protection. The LiPuDang Lake and the WuFangGang River were the most degraded areas. The studied parameters were correlated with urban, agricultural, industrial, and other major land use patterns. The results suggest that fecal contamination and nutrients, associated with certain land use practices, are the primary pollution factors in the Wujiang District. Detailed water quality monitoring and targeted management strategies are necessary to control pollution in Wujiang’s watersheds. Full article
(This article belongs to the Special Issue Assessment of Water Quality)
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19 pages, 10291 KiB  
Article
Predicting Cyanobacterial Harmful Algal Blooms (CyanoHABs) in a Regulated River Using a Revised EFDC Model
by Jung Min Ahn, Jungwook Kim, Lan Joo Park, Jihye Jeon, Jaehun Jong, Joong-Hyuk Min and Taegu Kang
Water 2021, 13(4), 439; https://doi.org/10.3390/w13040439 - 8 Feb 2021
Cited by 18 | Viewed by 4676
Abstract
Cyanobacterial Harmful Algal Blooms (CyanoHABs) produce toxins and odors in public water bodies and drinking water. Current process-based models predict algal blooms by modeling chlorophyll-a concentrations. However, chlorophyll-a concentrations represent all algae and hence, a method for predicting the proportion of harmful cyanobacteria [...] Read more.
Cyanobacterial Harmful Algal Blooms (CyanoHABs) produce toxins and odors in public water bodies and drinking water. Current process-based models predict algal blooms by modeling chlorophyll-a concentrations. However, chlorophyll-a concentrations represent all algae and hence, a method for predicting the proportion of harmful cyanobacteria is required. We proposed a technique to predict harmful cyanobacteria concentrations based on the source codes of the Environmental Fluid Dynamics Code from the National Institute of Environmental Research. A graphical user interface was developed to generate information about general water quality and algae which was subsequently used in the model to predict harmful cyanobacteria concentrations. Predictive modeling was performed for the Hapcheon-Changnyeong Weir–Changnyeong-Haman Weir section of the Nakdong River, South Korea, from May to October 2019, the season in which CyanoHABs predominantly occur. To evaluate the success rate of the proposed model, a detailed five-step classification of harmful cyanobacteria levels was proposed. The modeling results demonstrated high prediction accuracy (62%) for harmful cyanobacteria. For the management of CyanoHABs, rather than chlorophyll-a, harmful cyanobacteria should be used as the index, to allow for a direct inference of their cell densities (cells/mL). The proposed method may help improve the existing Harmful Algae Alert System in South Korea. Full article
(This article belongs to the Special Issue Assessment of Water Quality)
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18 pages, 4054 KiB  
Article
Diatom Algae-Indicators of Water Quality in the Lower Zarafshan River, Uzbekistan
by Sophia Barinova and Karomat Mamanazarova
Water 2021, 13(3), 358; https://doi.org/10.3390/w13030358 - 30 Jan 2021
Cited by 7 | Viewed by 4372
Abstract
This work is the first, the purpose of which was a comprehensive assessment of the ecological state of the lower reaches of the Zarafshan River using bioindication of water quality by diatoms based on species’ ecological preferences, pollution indices, statistics, and ecological mapping. [...] Read more.
This work is the first, the purpose of which was a comprehensive assessment of the ecological state of the lower reaches of the Zarafshan River using bioindication of water quality by diatoms based on species’ ecological preferences, pollution indices, statistics, and ecological mapping. A total of 198 species and subspecies of diatoms were first identified from 195 samples collected four times a year at six sites in the lower reaches of the Zarafshan River in 2009–2015. The richest species were Cymbella, Navicula, and Nitzschia. Pleurosira laevis, resistant to salinity, was first found in aquatic habitats in Uzbekistan. Bioindicators of nine environmental variables make up 91% of the list. Distribution analysis of variables, pollution indices (SLA—SládečDek index of saprobity), and toxicity indices (WESI—Water Ecosystem State Index) show increases in salinity, turbidity, and decreases in organic pollution downstream. The source of acidification can be the Navoi region. We found an increase in the ability to self-purify with an increase in species richness and abundance of diatoms in the lower part of Zarafshan. Thus, the ecosystem of the studied part of the river successfully copes with the incoming pollution from the middle part of Zarafshan and demonstrates some stability and successful self-purification with a water quality class of 2–3. The first studied lower reaches of the ecosystem of the Zarafshan River using bioindicators, statistics, and ecological mapping show that the problem of aridization in Central Asia does not necessarily lead to degradation of the river ecosystem and an increase in pollution, but with rational water use can improve water quality and self-purification processes. Hence, diatoms can be good indicators of river water quality in a semi-arid region and reflect the climate and anthropogenic load change. We recommend that attention be paid to nutrient and turbidity management and to expand state monitoring points to the lower part of the river up to the Karakul region. Full article
(This article belongs to the Special Issue Assessment of Water Quality)
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24 pages, 3426 KiB  
Article
Planktonic Invertebrates in the Assessment of Long-Term Change in Water Quality of the Sorbulak Wastewater Disposal System (Kazakhstan)
by Elena Krupa, Sophia Barinova, Sophia Romanova, Moldir Aubakirova and Nazia Ainabaeva
Water 2020, 12(12), 3409; https://doi.org/10.3390/w12123409 - 4 Dec 2020
Cited by 13 | Viewed by 2566
Abstract
The multicomponent composition of wastewater makes it challenging to assess its quality objectively, but the last one is a prerequisite for the safe re-use of wastewater. The solution to this problem should be aimed at finding criteria that make it possible to increase [...] Read more.
The multicomponent composition of wastewater makes it challenging to assess its quality objectively, but the last one is a prerequisite for the safe re-use of wastewater. The solution to this problem should be aimed at finding criteria that make it possible to increase the objectivity of assessing the water quality of reservoirs with multicomponent pollution. This work analyzes the water quality of the Sorbulak wastewater disposal system in the summer of 2017, based on chemical variables and zooplankton structure and assess the long-term changes in the water quality of Sorbulak. According to the Kruskal–Wallis test, in 2017, the differences between the studied water bodies in the content of nutrients and heavy metals were mostly insignificant. From 2000–2002 to 2017, nitrate, nitrite nitrogen, and heavy metals in Sorbulak significantly decreased. Zooplankton communities consisted of a relatively small number of eurybiontic species resistant to environmental factors. The variability of the quantitative variables of zooplankton was associated with the nutrients. Males dominated the population of the cyclopoid copepods Acanthocyclops trajani. In 2000–2002 individuals with morphological anomalies were found in cyclopoid copepods populations, but were absent in 2017. The appearance of individuals with morphological anomalies was associated with copper or lead. The chemical data and structure of zooplankton communities indicated that the toxic pollution of Sorbulak decreased by 2017 compared to 2000–2002. Our results demonstrate that the structural variables of zooplankton communities could be successfully used to assess the water quality of water bodies with mixed pollution. We recommend using not only the traditional set of biological variables (abundance, biomass, diversity indices, and the average mass of an individual), but also data on the structure of species dominance, the sex structure of copepod populations, and the presence of individuals with morphological anomalies for monitoring of water bodies with mixed pollution. Full article
(This article belongs to the Special Issue Assessment of Water Quality)
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19 pages, 3868 KiB  
Article
Groundwater Quality Characterization in an Overallocated Semi-Arid Coastal Area Using an Integrated Approach: Case of the Essaouira Basin, Morocco
by Mohamed Ouarani, Mohammed Bahir, David J. Mulla, Driss Ouazar, Abdelghani Chehbouni, Driss Dhiba, Salah Ouhamdouch and Otman El Mountassir
Water 2020, 12(11), 3202; https://doi.org/10.3390/w12113202 - 16 Nov 2020
Cited by 17 | Viewed by 3985
Abstract
In this study, hydrogeochemical analyses were combined with geographic information system (GIS) tools to investigate salinization sources of groundwater in the downstream part of the Essaouira basin, and to analyze the spatiotemporal trends in groundwater quality. To assess groundwater suitability for drinking purposes, [...] Read more.
In this study, hydrogeochemical analyses were combined with geographic information system (GIS) tools to investigate salinization sources of groundwater in the downstream part of the Essaouira basin, and to analyze the spatiotemporal trends in groundwater quality. To assess groundwater suitability for drinking purposes, the quality of sampled water was compared with the World Health Organization (WHO) and the Moroccan guidelines. Wilcox and US salinity laboratory (USSL) diagrams were used to evaluate groundwater suitability for irrigation. Hydrogeochemical analyses revealed that groundwater is of Na-Cl and Ca-Mg-Cl types. The analyses of the correlation between the chemical elements showed that the water–rock interaction and the reverse ion exchange are the major processes impacting groundwater degradation in the study area. The study of groundwater suitability for drinking and irrigation purposes shows that groundwater quality in the study area is permissible, but not desirable for human consumption. Additionally, groundwater is permissible for agricultural use but with high-salinity hazards. The spatial distribution of the physicochemical elements shows a general upward gradient from the north to the south and from the east to the west. The trend in groundwater quality during the last five years shows a shifting in the quality from the mixed Ca-Mg-Cl to the Na-Cl type. Full article
(This article belongs to the Special Issue Assessment of Water Quality)
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19 pages, 6250 KiB  
Article
Zooplankton as Indicator of the Ecological State of Protected Aquatic Ecosystems (Lake Borovoe, Burabay National Nature Park, Northern Kazakhstan)
by Elena Krupa, Sophia Romanova, Galym Berkinbaev, Natalya Yakovleva and Erlan Sadvakasov
Water 2020, 12(9), 2580; https://doi.org/10.3390/w12092580 - 16 Sep 2020
Cited by 17 | Viewed by 3305
Abstract
The enrichment of the protected Borovoe Lake with nutrients has taken place within the last 100 years, from the moment the first resort was formed on its shores. The purpose of this study was to assess the current ecological state of Borovoe based [...] Read more.
The enrichment of the protected Borovoe Lake with nutrients has taken place within the last 100 years, from the moment the first resort was formed on its shores. The purpose of this study was to assess the current ecological state of Borovoe based on the structure of zooplankton. According to the chemical data, in the summer of 2019, the content of nutrients in the water was, relatively, not high; the content of heavy metals was very low. Twenty-seven species were found in zooplankton. The average abundance of zooplankton was 988.8 thousand ind./m3 with a biomass of 1.52 g/m3. Rotifera dominated. Cladocera sub-dominated. The Shannon index values were 2.31 bit/ind. and 2.57 bit/mg; the values of Clarke’s W-statistics and Δ-Shannon were negative. The abundance of zooplankton increased more than nine times, but the average individual mass of an organism decreased from 0.0112 to 0.0016 mg over the past decade. Despite the relatively low content of nutrients, the structure of zooplankton demonstrated that the nutritional load on Lake Borovoe is currently close to critical. Statistical mapping of the data and redundancy analysis (RDA) showed that the primary source of lake pollution is the village of Borovoe and sanatoriums located on the southeast and northwest coasts. Full article
(This article belongs to the Special Issue Assessment of Water Quality)
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Review

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34 pages, 2065 KiB  
Review
Modification of the Water Quality Index (WQI) Process for Simple Calculation Using the Multi-Criteria Decision-Making (MCDM) Method: A Review
by Naseem Akhtar, Muhammad Izzuddin Syakir Ishak, Mardiana Idayu Ahmad, Khalid Umar, Mohamad Shaiful Md Yusuff, Mohd Talha Anees, Abdul Qadir and Yazan Khalaf Ali Almanasir
Water 2021, 13(7), 905; https://doi.org/10.3390/w13070905 - 26 Mar 2021
Cited by 157 | Viewed by 20940
Abstract
Human activities continue to affect our water quality; it remains a major problem worldwide (particularly concerning freshwater and human consumption). A critical water quality index (WQI) method has been used to determine the overall water quality status of surface water and groundwater systems [...] Read more.
Human activities continue to affect our water quality; it remains a major problem worldwide (particularly concerning freshwater and human consumption). A critical water quality index (WQI) method has been used to determine the overall water quality status of surface water and groundwater systems globally since the 1960s. WQI follows four steps: parameter selection, sub-indices, establishing weights, and final index aggregation, which are addressed in this review. However, the WQI method is a prolonged process and applied to specific water quality parameters, i.e., water consumption (particular area and time) and other purposes. Therefore, this review discusses the WQI method in simple steps, for water quality assessment, based on two multi-criteria decision-making (MCDM) methods: (1) analytical hierarchical process (AHP); and (2) measuring attractiveness by a categorically based evaluation technique (MACBETH). MCDM methods can facilitate easy calculations, with less effort and great accuracy. Moreover, the uncertainty and eclipsing problems are also discussed—a challenge at every step of WQI development, particularly for parameter selection and establishing weights. This review will help provide water management authorities with useful knowledge pertaining to water usage or modification of existing indicators globally, and contribute to future WQI planning and studies for drinking, irrigation, domestic, and industrial purposes. Full article
(This article belongs to the Special Issue Assessment of Water Quality)
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