Physicochemical Water Quality Research Articles

Effect of agriculture on surface water quantity and quality in Gilgel Gibe watershed, southwestern Ethiopia.

Monitoring water quality and quantity is crucial to be sure that water resources are sustainably used. However, there is no monitoring system of water quantity and quality in southwestern Ethiopia, despite expansion of agricultural activities demanding water resources. The objective of this study was to investigate the effect of agriculture on water quantity and quality with special emphasis on irrigation in southwestern Ethiopia. Data of water quantity was collected from four rivers and four irrigation canals during dry season of 2023. Physico-chemical water quality data was collected from 35 sites. Water quantity was calculated by estimating the water discharge of the rivers and irrigation canals. Weighted arithmetic water quality index was calculated to assess the status of the studied rivers. Principal component analysis was used to identify the relation of the sites with water quality parameters. This study revealed that the average amount of abstracted water for irrigation from the four studied rivers was 22,399 m3/day during the studied period, and the average percentage of abstracted water was 17%. Sites downstream of the irrigation site were characterized by poor water quality compared with the upstream sites. Sites surrounded by agricultural land use were correlated with chemical oxygen demand, electric conductivity, nitrate, orthophosphate, water temperature, and pH, whereas all sites surrounded by forest were positively correlated with dissolved oxygen. This study indicates that agricultural activities have a negative impact on surface water quality and quantity if not managed properly. Hence, we recommend sustainable use of water resources for the planned irrigation expansion.

Can dietary C:N ratio influence water quality and microbiology in recirculating aquaculture systems?

AbstractThe potential impacts of diet composition on water quality in recirculating aquaculture systems (RAS) have been studied only to a limited extent. This study examined the effects of different dietary C:N ratios on physiochemical water quality and associated microbiology in 12 pilot scale freshwater RAS with rainbow trout (Oncorhynchus mykiss). By adjusting the proportions of protein, carbohydrate, and fat, four diets with different C:N ratios—fully embracing the span observed in commercial diets—were formulated (CN8.5, CN9.3, CN10.0, and CN12.2). Each diet was administered to three separate RAS for 4 weeks at a daily feed loading of 1.67 kg/m3 make-up water. At the end of the trial (in week 4), concentrations of nitrite-N, nitrate–N, and dissolved COD, and microbial activity were significantly lower and water clarity was simultaneously higher in systems fed the CN12.2 diet as compared to the other diets. Microbial community compositions in system water and biofilter biofilms and the overall microbial abundance in system water were not affected. This was likely due to the molar C:N ratios in system water not correlating to the dietary C:N ratios and being very low (0.27–0.34) throughout all dietary C:N levels, suggesting that microorganisms were carbon limited in all RAS. Altogether, the results demonstrate that changing dietary C:N ratios can affect physicochemical water quality and microbial activity in RAS. In contrast, changing dietary C:N ratios did not affect water C:N ratios or water or biofilter microbial community composition at least within the span of dietary C:N ratios observed for commercial juvenile rainbow trout feeds.

Trends in Water Quality in a Tropical Kenyan River-estuary System: Responses to Anthropogenic Activities

Aims: To determine the spatial variation in physico-chemical water quality attributes in estuarine ecosystems of South Coast Kenya to inform its management. Study Design: We employed diagnostic research design where such factors as anthropogenic activities, hydrology, and accessibility were considered in choosing 12 sampling stations. A mixed sampling design (probability and non-probability) was used to sample. Place and Duration of Study: Four discharging rivers into estuarine system with a reference point were identified. 12 sampling points were earmarked and sampled for 12 months. Methodology: Nine selected water quality parameters were collected in triplicates monthly for 12 months. Temperature, dissolved oxygen, pH, conductivity, salinity and TDS were collected in situ using YSI Multiparameter meter (Professional plus) while nutrients were analyzed in the laboratory calorimetrically. Data was tested for normality and homogeneity of variances using Levene's and Shapiro-Wilk tests. Two-way analysis of variance (ANOVA), and Principal Component Analysis (PCA) were done using the 64-bit R Software version 4.3.0 to test for significant differences and correlate the parameters among the sampling sites respectively. Observed differences were considered statistically significant at P < 0.05. Results: The measured environmental variables differed significantly among the sampling stations (P < 0.05). temperature and salinity exhibited moderate to strong effect on water quality, while pH and nutrients (phosphates, nitrates, and ammonia) exhibited mixed effects with both negative and positive loadings on the Principal Components. It is demonstrated that the south coast estuary, Kenya is affected by two gradients: mineralization from the sea and the organic matter gradient at the upstream stations dominated by the fluvial inflows from the respective rivers. Conclusion: The south coast of Kenya estuary is impacted by natural processes and anthropogenic activities. we recommend for continued regular water quality assessment and monitoring to acquire sufficient data to shape policy frameworks towards its sustainable management.

Appraisement of groundwater quality status within Enugu, Nigeria, using physicochemical evaluation and water quality indices

Enugu state is notorious for potable water scarcity which forces residents to depend on polluted water sources. In this study, an appraisement of the quality status of groundwater from some areas within Enugu was conducted. Physicochemical characteristics of groundwater sampled from 15 boreholes that supply domestic water to Aninri, Awgu, Ezeagu, Udi and Oji River Areas of Enugu, Nigeria, were determined. A total of 45 water samples were obtained across both rainy and dry seasons. Standard methods were used to determine the physicochemical parameters and trace metals. The physicochemical results showed values within the WHO safe limits, except sulphate (1670 ± 21.5 mg L−1) in Mpu water samples, and high chloride levels in Ndeaboh and Mpu (18088 ± 29.4 and 1095 ± 23.9 mg L−1 for dry and rainy seasons, respectively). The pH values were predominantly slightly acidic, ranging from 5 to 8.2. Groundwater within Ukaete, Ndeaboh, Oduma and Amankpunato had very high levels of electrical conductivity (2897.80 ± 173.38, 31000 ± 45.9, 1672 ± 9.3 and 1222 ± 8.1) in the dry season, respectively; and 1665.06 ± 326.6, 5410 ± 2.4, 4860 ± 9.4, 1872 ± 19.3 in the rainy season, respectively. The higher chloride values observed, possibly due to a geogenic origin, could also be responsible for the higher values of the electrical conductivity. There were traces of copper and lead in the samples during the dry season; however, lead was not detected in most borehole water samples during the wet season. Fe was the only metal that recorded values above the WHO standard. Traces of copper in the samples may have resulted from corrosion in the copper pipelines, reservoirs or other metallic fittings used in the construction of the boreholes. The water quality index (WQI) of the borehole water examined was above 100 in all except Ogugu Awgu samples, indicating that borehole water was generally not potable and therefore unsuitable for domestic application or drinking. The observed results revealed that the groundwaters from the study area were contaminated with chloride and lead, causing the water parameters to be above standard limits. Lead at any concentration is deemed toxic according to USEPA. There is a need to treat borehole water supplies in the area before its application for domestic use.

Water physicochemical quality as driver of spatial and temporal patterns of microbial community composition in lake ecosystems

This study aimed at monitoring and management of the surface water and potentially pathogenic microbes of Lake Tonga (Algeria) with respect to. It characterized the main bacterial diversity patterns of Lake Tonga and predicted from water physicochemical parameters and water quality index (WQI) the distribution of bacterial species and the main indicator groups of faecal water contamination. Water samples were taken monthly at three sampling sites of different water depths. Several physicochemical parameters were measured; of which some were included in computing WQI to characterize the water quality of the lake. Counting, isolation and bacterial identification methods were used to characterize the existing aerobic heterotrophic bacteria. The composition of the microbial community of the waterbody of Lake Tonga included an abundant culturable bacterial flora belonging to several bacterial families and whose specific richness varied between water depths of the sites sampled. Species richness of the bacteria identified phenotypically varied between 7 and 11 per sample. The site with shallow water was the richest in bacterial species, compared to moderate and deep waters. The redundancy analysis showed the main physicochemical drivers of the microbial community composition. Our findings showed that high WQI scores indicated the water quality deterioration which triggered the increase in total load of faecal indicator bacterial groups. This study identified in Lake Tonga an important culturable aerobic bacterial flora whose specific richness and distribution varied spatially following the effects of water physicochemical parameters. Lake Tonga needs an integrated management plan to mitigate human disturbances declining water quality.

Impact of lytic phages infecting Salmonella enterica subspecies arizonae on physicochemical and microbiological water quality of the old Port of Bizerte (Tunisia, SW Mediterranean Sea)

Phage therapy is among recent innovative technology to improve wastewater quality. Previous phage studies have focused on the interactions of phages with bacterial host-cells or the impact of environmental conditions on phage-host cell dynamics. In this research, we particularly examined the impact of phages on a marine physicochemical and microbiological environmental characteristic. Following three days of incubation, seawaters receiving separately phage fBC-Eco01 (OM272052) and phage PA25, undergone a temperature increase of 1.7°C and 2.5°C, respectively. Seawater salinity values saved an increase in conductivity over time that ranged between 51.03 and 53.94 µS and from 51.04 to 53.7 μS for the phage PA25 and the phage fBC-Eco01, respectively. A significant decrease in dissolved oxygen levels of 2,1mg/L were reported following the addition of both phages PA25 and fBC-Eco01 during three days of incubation, compared to a decrease of 1mg/L in the control seawaters. The TOC increased from 0.33 ppm to 0.67 ppm in the presence of the PA25 phage and from 0.2 ppm to 1.51 ppm after the addition of the fBC-Eco01 phage, compared to control that saved values decreasing from 0.35 ppm to 0.05 ppm. The absorbance and fluorescence spectrophotometry values were also affected by phages addition. Moreover, phages addition reduced total aerobic mesophilic bacteria (TAMB) and Total aerobic thermophilic bacteria (TATB) abundance, corresponding to a decrease of 2 Ulog and 1 Ulog discharge, respectively following addition of PA25 and 3 Ulog and 2 Ulog discharge, respectively with addition of fBC-Ec01 phage.

Safety of Tap Water in Terms of Changes in Physical, Chemical, and Biological Stability

Monitoring the quality of tap water in the distribution system and the ability to estimate the risk of losing its sanitary safety is an important aspect of managing the collective water supply system. During monitoring, the physical, chemical, and biological stability of water was assessed, which is the main determinant ensuring the appropriate quality of water for consumers. The physicochemical and microbiological quality of water was analyzed for two distribution systems (DSs), including the analysis of heavy metals (Zn, Fe, Mn, Cr, Ni, Cu, Cd, Pb). The tests carried out showed that in both distribution systems, the water supplied to consumers met the guidelines for water intended for human consumption. It can be considered that the risk of uncontrolled changes in water quality in DSs with an average water production of <10,000 m3/d and the length of water pipelines < 150 km is very low. The water introduced into the system differed in the place of water intake and water purification technology, which influenced the final water quality. In DS(II), higher values were recorded for hardness, conductivity, calcium, alkalinity, nitrates, and DOC. It was found that the content of heavy metals during water transport to the consumer increased in the case of DS(I) for Zn, Ni, Cu, Cd, and Pb, and in the case of DS(II) for Fe, Mn, Ni, Cu, Cd, and Pb. The observed differences resulted from the different quality of the intake water as well as from different materials used to build internal installations and their age and technical condition. The analyzed tap water was characterized by physical and chemical stability. However, the water did not meet the guidelines for water biostability due to the increased content of biogenic substances.

Assessment of the Microbial and Physicochemical Quality of Water: Evidence from Selected Groundwater Sources from The Coastal Region of Ondo State, Nigeria

The coastal area of Nigeria frequently experiences pollution of water due to various human activities that may compromise the quality of underground water. This study evaluated the microbial contamination and quality indicators of groundwater in the coastal environment of Ondo State, Nigeria. Nine underground water samples were collected from the study area and assayed using conventional microbiological techniques coupled with standard physical and chemical analytical procedures. Results revealed that all the samples had total viable bacterial counts, fungal counts and coliform counts which ranged from 61.25 to 85.32 CFU/100 mL, 10.00 to 35.32 SFU/100 mL and 6 – 24 MPN/100 mL respectively, which were higher than the set WHO limit. Results also revealed that the samples from Irele and Ese- Odo Local Governments Areas had acidic pH in the range of 4.20 -5.21 considered to be below the WHO permissible limit whereas only one of three samples from Ilaje Local Government had acidic pH of 5.23. The concentrations of the heavy metals varied among the samples with manganese (0.183-0.311) mg/L exceeding the 0.08 mg/L prescribed by the WHO. The high microbial load, acidic pH of 4.20 -5.23 in 77.78 % of samples and elevated amount of certain metals suggest the need for water quality monitoring and intervention by government and oil multinationals operating in the area noting that adequate supply of safe - drinking water will improve human health and reduce the burden of waterborne diseases.

Physical and chemical features of hydro-geologically connected wetlands in the Abbay River basin, Ethiopia

Physico-chemical water quality assessment is vital for wetland characterization, detecting environmental stress affecting the ecosystem and wetland management interventions. Therefore, this study aimed at comprehensive analysis of water quality parameters of six hydro-geologically connected wetlands in West Gojjam zone, Amhara region, Ethiopia. Water quality data was collected for one year (from June 2022 to April 2023) during four sampling seasons (pre-rainy, main-rainy, post-rainy and dry seasons) from twelve purposively selected sampling sites. In-situ measurements and nutrient analysis were carried out following standard procedures. Water quality index (WQI) was also computed by the weighted arithmetic water quality index method (WAWQI) based on selected parameters. Phosphate ranged from 0.24 mg/l (Kurt Bahir) to 1.80 mg/l (Zindib) and nitrate ranged from 2.12 mg/l (at Gudera) to 3.25 mg/l (at Geray). This increased nutrient concentration and the decreasing trend in DO level clearly indicates their ecological degradation. There was a statistically significant difference (P < 0.05, One-way ANOVA) in the mean measurements of some of the parameters among the study wetlands and among the study seasons. The PCA also clearly shows the most influential variables responsible for the variation among the wetlands. The study concluded that the wetlands water quality has been degraded. Therefore, regular water quality monitoring is recommended to reduce further deterioration.

Physicochemical quality of underground water from agricultural influence

GGroundwater in rural areas is the only source of supply for consumption and various activities. It is exposed to various pollutants that arrive through the subsoil layers. The objective of this study was to evaluate the quality of water from 15 wells in the municipality of Cotaxtla, through physicochemical variables such as pH, conductivity (EC), salinity and total dissolved solids (TDS), where the results were compared with the regulations according to its use. The samples were collected according to NOM-230-SSA1-2002. The physicochemical variables were determined with the multiparametric Consort C6010. Results ranged from pH 6.71-8.04, EC 228-4500 mS/cm, salinity 0.13-2.42 mg/L, and TDS 132-2250 mg/L. In every case, water is destined for agricultural use, where 52% is used for livestock and 80% for consumption, 60% of the wells are community and supply 612 inhabitants. According to Mexican regulations, the results obtained from EC, 13% of the wells were not suitable for consumption, in relation to the TDS results, 33% were not suitable for consumption and 13% were not suitable for agricultural irrigation. The pH showed values within the norm, however, one showed a pH of 6.71 ± 0.043, while the rest were found between 7.4 ± 0.03-8.1 ± 0.19. In all values, significant differences were shown between the sites analyzed

Assessment of Physicochemical Quality and Challenges of Municipal Sewage Water in Manchalapur Village in the Karnataka, India

The present study was carried out on characterization of municipal sewage water tank of Manchalapur village near Raichur city in Karnataka. The water samples were collectedeight times from four different locations like inlet, outlet and water spreading area of the Manchalapur tank during the year 2018-2019 in monsoon and post monsoon season. The collected water samples were analyzed for the water quality parameters by using standard procedure. The results obtained were compared with Central Pollution Control Board (CPCB) and Bureau of India Standards (IS 2296:1992) water quality requirements for irrigation. The results showed that pH (7.89, 8.54), Electrical Conductivity (1.41, 1.48 dSm-1), Total Dissolved Solids (929.63, 1031.56 mg L-1), Carbonate (2.15, 0.86 mg L-1), Bicarbonate (7.71,4.99 mg L-1), Nitrate (26.90, 34.09 mg L-1), Phosphate (9.85, 6.20 mg L-1), Calcium (3.38, 2.77 mg L-1), magnesium (5.16, 4.13 mg L-1), Sodium (0.85, 0.92 mg L-1), Biological Oxygen Demand (1396.88, 1252.31 mg L-1), Chemical Oxygen Demand (14480, 8573.0 mg L-1), Dissolved Oxygen (7.91, 8.02 mg L-1) and turbidity (13.33, 8.77 NTU) for monsoon and post monsoon respectively. All the water quality parameters were within the recommended range of irrigation standards except the parameters BOD, COD, DO and turbidity. The results could be applicable advice to farmers and agricultural researchers for proper management and use of tank water for agricultural purpose.

Evaluation of Water Quality Based on Macrozoobenthos as Bioindicator in Ngesong Spring and The Ditch, Batu-East Java

The Ngesong spring is a clean spring that is used by society as a spring of clean water and as a tourist attraction. The Ngesong spring has a ditch that flows up to the society settlement, where the water is used for agricultural irrigation and plantation irrigation. The utilization of the Ngesong spring as a tourist attraction and its ditch through agriculture, settlements, and society settlements have great potential to cause pollution and degradation of water quality, so it is necessary to evaluate water quality. Therefore, it is necessary to monitor the quality of this water, one of which is using the macrozoobenthos community structure as a bioindicator. The research was conducted in four locations, namely a water spring and the channels that will be used for agriculture, plantations, and settlement activities, in September and October 2022. The variables observed in this study include the physicochemical quality of water, namely water temperature, conductivity, power of hydrogen (pH), dissolved oxygen (DO), biological oxygen demand (BOD), and total suspended solids (TSS), as well as community structure and macrozoobenthos diversity. The results of this study indicate that there are 26 macrozoobenthos families belonging to 12 orders, for a total of 968 individuals. Water springs are the location with the highest diversity and evenness index values, with H = 2.27 and E = 0.54. The results of the analysis of macrozoobenthos family relationships as an indicator of water quality using the Family Biotic Index (FBI) and Average Score Per Taxon (ASPT) showed that the Waterspring site has very clean waters and no organic pollution. At Waterspring sites that have good water quality, the families Perlidae, Nemouridae, Limnephilidae, Viviparidae, Chironomidae, and Euphaeidae were found. Meanwhile, according to the FBI, sites that have highly organically polluted waters are the ditches that had agricultural activity and, based on ASPT, settlement activity.

Phytoplankton functional dynamics in relation to some physicochemical parameters in Lake Kuriftu (Oromia, Ethiopia)

The water quality of Lake Kuriftu is deteriorating, and monitoring programs are almost nonexistent in Ethiopia. Phytoplanktons are good indicators of environmental changes due to their fast response to a wide range of stressors. The phytoplankton functional groups (FGs) can be used as water quality indicators. This study aimed to assess the dynamics of phytoplankton functional groups (FGs) in relation to some physicochemical water quality parameters measured at three sites in Lake Kuriftu. Samples for the analysis of biological and physicochemical parameters were collected monthly, from December 2020 to April 2021. The results of the physicochemical parameters revealed that Lake Kuriftu is turbid (21.37 to 59.86 NTU), has a thin euphotic depth (ZSD0.304 to 0.548 m), and is eutrophic. Ninety-seven (97) phytoplankton taxa were identified and classified into 16 Reynolds Functional Groups (RFGs), of which six (J, MP, X1, Lo, S1, and F) were represented by more than six species. FGs S1, SN, Lo, and Lm, which often form Harmful Algal Blooms, contributed together about 33.54 mg L−1, or 87.84 %, of the total biomass recorded for Lake Kuriftu, demonstrating the water quality of the lake is deteriorating. Among the FGs, the most dominant (in terms of biomass) was S1, followed by J at all sites and in all sampling months. The results of redundancy analysis (RDA) revealed that the main driving factors of phytoplankton FG biomass and composition were TP, ZSD, TN, Salinity, and ammonia. Among these, TP and salinity impacted the FGs negatively, while TN and ammonia influenced them positively. Thus, the physicochemical parameters have a significant impact on the distribution of phytoplankton FGs, suggesting that the use of FGs for water quality monitoring programs is useful. To promote wise use and conservation of the lake ecosystem, more intensive study should be carried out on the biological and physicochemical aspects of the lake, as it is part of a tourist attraction area and a source of income for local inhabitants.

Plankton Diversity and Hydro-biological Parameters at Wazirabad Barrage in Yamuna River

This study conducted a comprehensive investigation into the qualitative and quantitative analysis of plankton diversity and Physico-chemical water quality parameters in the Yamuna River. Samples were collected from the Wazirabad barrage from June 2022 to November 2022, revealing a diverse phytoplankton community consisting of 50 genera distributed across five major classes. The abundant classes were Bacillariophyceae, with 18 genera, followed by Chlorophyceae with 20 genera, Cyanophyceae with 9 genera, Euglenophyceae with 2 genera, and Dianophyceae represented by a single genus. The qualitative analysis uncovered a zooplankton community with 20 genera from Protozoa and Rotifera, Copepoda, and Cladocera. Protozoa were represented by two genera, Copepods exhibited eight genera, Cladocera included five genera, and Rotifera featured four genera. The most abundant class of phytoplankton is Chlorophyceae and Zooplankton is Copepods. Physico chemical water quality parameters more fluctuation during the study period. These findings offer valuable insights into the biodiversity and composition of phytoplankton and zooplankton communities in the Wazirabad Barrage ecosystem.

Spatio-temporal evaluation of the impact of anthropogenic stressors on physico-chemical characteristics and water quality of the River Ganga using GIS-based approach in the middle Gangetic Plains at Patna, Bihar, India.

The present study aimed to assess the impact of anthropogenic stressors on the physico-chemical characteristics and water quality of the River Ganga employing a GIS-based approach in the middle Gangetic Plain at Patna, India. After the survey, sand mining, bridge construction, and disposal of untreated domestic and sewage wastes were selected as major anthropogenic stressors. A total of 48 samples were collected in pre-monsoon and post-monsoon seasons of 2022 and were analyzed for 16 physico-chemical parameters, namely water temperature (WT), pH, electrical conductivity (EC), total dissolved solids (TDS), turbidity, dissolved oxygen (DO), biological oxygen demand (BOD), total hardness (TH), Ca2+, Mg2+, Na+, K+, Cl- and SO42- ions, following standard protocols. The WQI was calculated using the Weighted Arithmetic Water Quality Index (WAQWI) method and spatial maps were created using ArcGIS software. The result revealed significant seasonal variation in several physico- chemical parameters except for Ca2+, K+ and TA (p > 0.05). ANOVA revealed significant variation for BOD and COD at Ghagha and Triveni, whereas for nitrate at Gai Ghat reference and impact sites, respectively. The Water Quality Index (WQI) revealed a deterioration in water quality by 60% in post-monsoon season. HCA revealed that the WQI was mostly governed by TDS, TH, TA, and EC.

Improving Hasanuddin University Lake Water Quality by Controlling Contamination Sources and Biological Monitoring Systems

Hasanuddin University Lake in Indonesia is a water tourism destination that offers natural beauty and comfort. In addition, the lake functions as an important scientific development park for the university. Even though its location is on campus, the surroundings of the campus are residential areas and various life activities. Recently, weed growth has occurred, which could be an indication of contamination and may hinder its useful function. Therefore, this study investigates the physicochemical quality of water, the pollution index, and its monitoring, attempting to make the campus lake continue to function sustainably. The research was carried out at the peak of the dry and rainy seasons, with laboratory examinations based on standard methods for quality parameters that follow lake use function standards. The results showed that most of the water quality parameters measured needed to meet the required quality standards. Based on the scoring results using the water pollution index method, lake water is classified as lightly to moderately polluted, which requires protection. The monitoring method is prepared with the addition of a biological indicator system. In line with that, intensification of the diversity of greenery around the lake and environmental management in an integrated manner with the surrounding settlement. The conclusion is that there is a need for complementary monitoring between physicochemical and biological methods and management coordination with the surrounding territories.

Integrated Assessment of Kirala Kele Wetland Health: Bridging the Gap between Water Quality Parameters and Biotic Components

Abstract The present study was carried out to assess the health of the Kirala Kele Wetland, Sri Lanka, by coupling water quality indices and bioindicators. A total of 12 sampling sites were selected to represent different land-use patterns of the Kirala Kele Wetland using purposive sampling technique, and sampling was conducted from March 2021 to May 2021, on a monthly basis. Triplicated samples (n = 3) were obtained for each sampling event at each sampling site. Aquatic macroinvertebrates were collected from each site to determine the biological water quality using the Biological Monitoring Working Party (BMWP) score. Weighted Arithmetic Water Quality Index (WAWQI) was calculated to understand the physicochemical parameters of water, and the mean values of physicochemical water quality parameters were compared with the Sri Lankan water quality standards. According to the WAWQI for the different sampling sites, water is not suitable for drinking without treatment. The resulted BMWP score (BMWP = 61) shows that the water quality is acceptable (clean but slightly impacted) for biotic components of the wetland in accordance with the aquatic macroinvertebrates present. Spatial variation in water quality parameters and the aquatic macroinvertebrates were taken into account, and the temporal variation in water quality parameters within the 3 months from March to May was considered.

Microbial and physicochemical water quality changes within distribution and premise plumbing systems during a chlorine conversion

A strategy for nitrification control within chloraminated drinking water systems (CDWSs) is to temporarily switch from chloramine secondary disinfection to free chlorine, also known as a free chlorine conversion (FCC). However, the long-term and beneficial effects of FCCs are unclear, especially regarding opportunistic pathogen occurrence. In this study, the impacts to microbial and physicochemical parameters were monitored throughout a CDWS implementing a FCC. Water samples were collected weekly for 4–6 weeks before, during, and after a FCC at eight locations: four distribution system and four residential sites. Monochloramine residual (mean±standard deviation) before and after the FCC averaged 1.8±0.9 and 1.6±1.0 parts per million (ppm) for all sites, respectively. Free chlorine levels averaged 2.3±0.9 ppm. There were no significant differences in turbidity and hardness at each location during the three time periods, but some were noted for pH, temperature, and orthophosphate levels across various sites and sampling periods. For all locations, heterotrophic plate count levels were lower during the FCC compared to the periods before and after. All samples from one residence were culture positive for P. aeruginosa which exhibited high levels before the FCC, decreasing levels during, and steadily increasing levels after. Additionally, one week prior to the FCC, sediment samples from two elevated storage tanks, ET-1 and ET-2, were analyzed with ET-1 displaying higher levels of culturable heterotrophic bacteria and molecularly detected total bacteria, Legionella spp., and nontuberculous mycobacteria (NTM), as well as presence of culturable P. aeruginosa and total coliforms compared to ET-2. Fourteen P. aeruginosa and total coliform isolates were whole genome sequenced with genetic differences observed depending on the sampling location and timepoint. Collectively, the observed differences in chemical and microbial parameters advocates for a better understanding of the effects associated with implementing FCCs to determine both their effectiveness and potential risks/rewards to water quality.

Study of the Physico-Chemical and Microbiological Quality of Water from River Innaouene, Taza Province, Morocco

Study of the Physico-Chemical and Microbiological Quality of Water from River Innaouene, Taza Province, Morocco

Comparison of the zooplankton-based RCC to Carlson’s trophic state indices and water quality parameters

Zooplankton is not included as a biological quality element, even though it is a key component of pelagic food webs. The data on zooplankton community structure can be used to evaluate the trophic state of lakes through an RCC Index, based on quantitative proportions between the main zooplankton groups. As previous investigations have related the index only to the Secchi disc transparency, the aim of this study was to compare the Index to a set of water quality parameters and trophic state indices. Two sandpit lakes with contrasting characteristics were selected as model lakes for the study. A total of 57 samples were collected simultaneously with the physicochemical water quality parameters between 2016 and 2020. Carlson’s trophic state indices were used to assess the trophic state of the lakes. Pearson correlation coefficient and Principal Component Analysis were used to assess the observed correlations between the measured parameters and to distinguish what factors regulate zooplankton community structure. Overall, 86 zooplankton taxa were identified. RCC Index ranged from 2 in the small sandpit lake to 87 in the big sandpit lake. A highly significant negative correlation was found between the RCC Index and the values of TP and COD. The results complement the arguments for the inclusion of zooplankton as a BQE for the assessment of the status of lakes.