Chemical Water Quality Parameters Research Articles

CHARACTERIZATION OF PHYSICO-CHEMICAL AND BIOLOGICAL PARAMETERS IN AREAS WITH FISHING POTENTIAL

In the present study, the physico-chemical quality of the water in the Midia coastal area, the Tasaul Lake and the Siutghiol Lake water bodies were analyzed, as integrated sites in the territory of the North Dobrogea FLAG. This study allows establishing the state of favourability of the aquatic ecosystem, focusing on the chlorophyll content as the basis of the trophic level. The premise of a stable ecosystem induces the possibility of developing natural fish resources. An essential attribute in the context of preserving natural heritage and increasing the attractiveness for fishing activities, is the need to evaluate the qualitative and quantitative profile of the phytoplankton and, respectively, the eutrophication indicators. If aquaculture activities will be developed in the analyzed areas in the future, they could increase the economic value of the Romanian sector of the Black Sea. The biological analyzes of the water quality are the basis of the substantiation of some methods of its determination and evaluation. Thus, testing the concentration of chlorophyll, the classes of algae and the photosynthetic activity, are useful for the evaluation of eutrophication in the aquatic environment, but also for the evaluation of productivity in the surface waters studied. At the same time, the determination and evaluation of the physical and chemical parameters of water quality allowed the realization of some correlations with the structure of the biota. In this sense, the analysis methods are based on the use of modern equipment based on real time (in situ) determinations.

Determination of Water Quality Index of Drinking Water in Aligarh District, UP, India

Water is perhaps the most precious natural resource after air. Though the surface of the earth is mostly consists of water, only a small part of it is usable, which makes this resource very limited. This precious and limited resource, therefore, must be used with prudence. As water is required for different purposes, the suitability of it must be checked before use. Nowadays fresh water cannot be used directly for drinking purposes due to contamination and pollution. So treatment is used before it is used for drinking or for industrial processes. Also, sources of water must be monitored regularly to determine whether they are in sound health or not. Poor condition of water bodies are not only the indictor of environmental degradation, it is also a threat to the ecosystem. In industries, improper quality of water may cause hazards and severe economic loss. Thus, the quality of water is very important in both environmental and economic aspects. Thus, water quality analysis is essential for using it in any purpose. The quality of water depends upon its source of history. The history of water signifies the terrain through which water is flowing, its origin and most important the extent to which it is contaminated on its way by impurities, sediments and industrial waste. The solubilisation and fragmentation of the terrain through which it flows determines its quality. The extent of dissolved solid materials present in water decides its quality. Such quality is also decided by the solubility of the geological deposits, contact of water with sediments, time of interaction and special factors related to environment. To ascertain suitability of water for consumption, it is necessary to undertake examination of quality of water. . Major information on the quality of water is obtained by physical examination. considered in the present paper for calculating the WQI such as pH, Total alkalinity, Calcium, Magnesium, Chloride, Sulphate, Nitrate and also calculated the seasonal variations of physio- chemical parameters of water quality of Aligarh District.

20-year water quality analysis reveals spatial variability and long-term changes at North Carolina's Masonboro Island National Estuarine Research Reserve

Urbanization impacts, especially stormwater runoff and pollutant discharge, pose ecological threats to coastal ecosystems globally. Long-term environmental monitoring datasets and assessments are used to quantify anthropogenic impacts on ecosystem health. This study synthesized twenty years (2002–2021) of water quality data from the National Estuarine Research Reserve System-wide Monitoring Program at the understudied Masonboro Island Reserve (North Carolina, United States) and provided an analytical methodology that can be applied to other Reserves and monitoring programs world-wide. Time series and correlation analyses of biological, chemical, and physical water quality parameters were used to identify spatiotemporal trends of nutrient dynamics and phytoplankton biomass at three stations within a 5-km stretch of the Atlantic Intracoastal Waterway. Heterogenous water quality conditions were observed between stations, especially for chlorophyll a, and were influenced by the relative proximity to marine waters, human developments, and urban tidal creeks. Long-term trends indicated significant water quality changes (i.e., increased chlorophyll a, reduced pH and salinity) related to anthropogenic influences. An unexpected and rapid shift in nutrient dynamics occurred around 2007, marked by significantly decreased ammonium and orthophosphate concentrations, which considerably reduced DIN/DIP ratios. This positive change was potentially influenced by sewage infrastructure improvements and stormwater wetland construction, removing waste-derived nutrients that previously entered the ecosystem. Impacts of major storms were also observed with weeks of hypoxia and low salinity following Hurricane Florence. These findings emphasized the value of long-term trend analyses of monitoring program data at multiple sites and provided insights into the significant water quality impacts of urbanization and benefits from wetland protection. This study further encourages the evaluation of long-term water quality monitoring datasets in estuarine environments globally.

Analysis of Residential Well Water Quality Around People's Gold Mines in the Tourist Area of Dusun Selindungan

The Sekotong area has natural charm and potential mining. This area is one of the preferred destinations for visits by local and foreign tourists. However, apart from that, the Sekotong area is also famous as a community gold mining area. Mining activities carried out still use traditional methods, which are very far from environmentally friendly principles, so they can have impacts, including causing a decrease in the quality of residential well water. This research was conducted to determine the water quality of residential wells around community gold mining in the tourist area of Dusun Selindungan Eleven well water samples were taken using a purposive sampling method based on the distance of the well to the source of gold mining waste disposal and are still used by residents to meet their daily needs. Physical, chemical and biological water quality parameters of water samples were investigated in the laboratory, except temperature and pH were measured directly in the field. Data for each water quality variable was analyzed to determine the pollution index. The results show that DO, TDS, content of phosphate, E. Coli bacteria and total coliforms in well water from the study area generally exceed quality standardsWell water in an area that is a different distance from the people's gold mining waste disposal site has each been contaminated with manganese and mercury, although it is still below quality standards.

Wastewater as a nutrient source for hydroponic production of lettuce: Summer and winter growth

Solutions combining soilless cropping systems with wastewater reuse can offer benefits in the agriculture sector, reducing pressure on water resources, promoting sustainable production, and reclaiming wastewater. However, assessing the sanitary risks associated with wastewater reuse is of utmost importance. This study aimed to investigate the hydroponic growth of lettuce (Lactuca sativa var. crispa L.) in wastewater from an urban treatment plant with different levels of treatment and evaluate potential sanitary risks. Crop growth took place in a greenhouse, during summer and winter periods, using wastewater after primary (PTW) or secondary (STW) treatment, and a nutrient solution (NS), as control. Physical and chemical water quality parameters, morphological crop growth parameters, and environmental conditions inside the greenhouse were monitored. Toxicity analyses were carried out through cell viability assays with the Caco-2 cell line and total coliforms and Escherichia coli (E. coli) were determined. Wastewater-grown plants achieved acceptable growth, even though presenting lower fresh weight than NS-plants. STW-plants’ growth was limited essentially by nutrient deficiency, and PTW-plants were affected by nutrient deficiency, pH values, solid load, and N-NO2 concentration. Higher temperatures in summer led to faster crop growth, and lower temperatures in winter allowed better nutrient uptake by the crop. Wastewater-grown plants did not evidence toxicity in leaf extracts up to 1 % w/v. Coliform enumeration data indicated an accumulation in plant roots, with high removal from the wastewater. E. coli was not detected on plants’ leaves and total coliforms were within acceptable limits. Furthermore, the results point to an improvement in the wastewater quality, with minimum removal values of 75.2 % BOD5, 83.1 % COD, 43.4 % P, 44.9 % N, and 90.4 % K. The results demonstrated the viability of wastewater reuse for hydroponic production allowing a better understanding of its processes and contributing to mitigating water scarcity for food production, and the impacts of treated wastewater discharge in freshwater courses, particularly those associated with nutrient delivery to aquatic systems.

Physicochemical Characteristics of Water in the Bontanga Irrigation Dam in the Guinea Savannah Agro-Ecological Zone of Ghana

Fresh water resource is one of the most significant natural assets of a country. Irrigation dams are usually used for irrigation purposes and also often serve as a source of water for domestic use. Due to this, there is a need for proper maintenance, assessment, and sustainable use of irrigation dams. This study assessed the physicochemical properties of the water in the reservoir of Bontanga irrigation dam situated in the Guinea Savannah Agro-Ecological Zone of Ghana. The study assessed four (4) physical and fourteen (14) chemical water quality parameters of the water for irrigation to know whether they are within the acceptable threshold set by the Food and Agriculture Organization (FAO) and the World Health Organization (WHO). Sampling techniques used in this study were stratified and purposive samplings. The reservoir of the dam was divided into nine (9) strata and in each stratum, 5 samples were taken making a total of 45 samples. Samples taken in each strata were composited making it a total of 9 samples. The water samples were collected into well-labelled polythene bottles and kept in an ice chest with ice cubes. The samples were transported to the Ecological Laboratory of the University of Ghana for analysis. The parameters analyzed were pH, electrical conductivity (EC), temperature, total dissolved solutes (TDS), chloride (Cl-), sulphate (SO42-), bicarbonate (HCO3-), carbonate, PO4-P, nitrites/nitrate (NO3-N), total dissolved solids (TDS), magnesium (Mg2+), calcium (Ca2+), sodium (Na+), boron, total alkalinity, ammonia (NH4-N) and potassium (K+). A greater percentage of the results obtained were within acceptable limits except potassium which was slightly higher. This could be the result of farming activities in the catchment of the dam. In general, the water in Bontanga irrigation dam can be considered suitable for irrigation purposes.

Evaluation of water quality and trophic status in relation to seasonal water mixing in a highland Lake Ardibo, Ethiopia.

The aim of the present study was to evaluate the spatio-temporal variability of various physical and chemical parameters of water quality and to determine the trophic state of Lake Ardibo. Water samples were collected from October 2020 to September 2021 at three sampling stations in four different seasons. A total of 14 physico-chemical parameters, such as water temperature, pH, dissolved oxygen (DO), electrical conductivity, turbidity, alkalinity, Secchi-depth, nitrate, ammonia, silicon dioxide, soluble reactive phosphorus, total phosphorus, chloride, and fluoride were measured using standard methods. The results demonstrated that temporal variation existed throughout the study period. Except for turbidity, the water quality of the lake varied significantly within the four seasons (ANOVA, p < 0.05). DO levels decreased significantly during the dry season following water mixing events. Chlorophyll-a measurements showed significant seasonal differences ranging from 0.58 μg L-1 in the main-rainy season to 8.44 μg L-1 in the post-rainy period, indicating moderate algal biomass production. The overall category of Lake Ardibo was found to be under a mesotrophic state with medium biological productivity. A holistic lake basin approach management is suggested to maintain water quality and ecological processes and to improve the lake ecosystem services.

Spatial and temporal analysis of physical and chemical properties of Short Creek

Freshwater systems are vitally important. Ecologically, rivers and streams are responsible for immense biodiversity, providing habitat for terrestrial and aquatic flora and fauna. Freshwater systems benefit humans in innumerable ways, providing drinking water to millions of people, means of transportation, food sources, and recreation areas. Nevertheless, the degradation of freshwater ecosystems continues to worsen at alarming rates. Long-term water quality monitoring can help determine the best management practices to improve and restore waterways. This study assessed changes in water chemistry in the Short Creek tributary located in Wheeling, WV, comparing historical data to current, focusing on physical and chemical water quality parameters data recorded from single monthly points obtained from historical data and averaged monthly points from current data. Short Creek represents 4 of 11 sites where data is collected weekly year-round. This data collection has been ongoing since 2018 and is part of a more extensive compilation hosted by Three Rivers Quest and the WVU Water Resource Research Institute. Water temperature, dissolved oxygen, chloride, specific conductivity, pH, and turbidity were recorded and analyzed utilizing Excel and RStudio. The increased frequency of monitoring provides a more accurate representation of Short Creek's overall condition. Both historical and current datasets were incomplete but generally did not show declines. A concerted effort in long-term water quality monitoring is necessary for understanding stream health. Current and historical data combined give us more resolution to estimate trends in water chemistry, better determine stream health progress, and assist in implementing best management practices.

Long-term trial of a community-scale decentralized point-of-use drinking water treatment system

Two billion people lack access to safely managed drinking water services, many of these are in low/middle income countries where centralised systems are impractical. Decentralised point-of-use drinking water treatment systems offer alternative solutions in remote or resource constrained settings. The main aim of this study was to assess the long-term (3 year) operation and performance of a point-of-use drinking water treatment system (POU-DWTS). A biologically contaminated urban drainage pond was used as a water source and the quality of the produced drinking water was assessed over two independent trials. The decentralised POU-DWTS combined ultrafiltration membranes with disinfection from electrochemically generated hypochlorous acid (HOCl). The operational parameters, such as flow rate, free available chlorine and transmembrane pressure, were monitored in real-time and recorded via a remote monitoring system. Water quality from the source and treated water was assessed over two trial periods within the 3-year operational trial: an 11-week period at the start and a 22-week trial at the end. All water samples were assessed for a range of basic, chemical, microbiological and metal water quality parameters. The results demonstrate that the decentralised POU-DWTS is capable of continuously producing high quality drinking water when HOCl is continuously used to dose water prior to entering the ultrafiltration [UF] membranes. Over the 3-year operational study, the continuous dosing of HOCl pre-UF membranes resulted in stable permeability, indicating no occurrences of irreversible biofouling within the UF membranes and that good membrane ‘health’ was maintained throughout. As such, there was no need to replace the UF membranes nor undertake acid/alkaline chemical cleans at any point throughput the three-year study. The POU-DWTS continuously produced high quality drinking water, resulting in 6453 m3 of drinking water produced over the trial period, that met international water quality standards, at a community scale within the location studied.

Prediction of microbial activity and abundance using interpretable machine learning models in the hyporheic zone of effluent-dominated receiving rivers

Serving as a vital linkage between surface water and groundwater, the hyporheic zone (HZ) plays a fundamental role in improving water quality and maintaining ecological security. In arid or semi-arid areas, effluent discharge from wastewater treatment facilities could occupy a predominant proportion of the total base flow of receiving rivers. Nonetheless the relationship between microbial activity, abundance and environmental factors in the HZ of effluent-receiving rivers appear to be rarely addressed. In this study, a spatiotemporal field study was performed in two representative effluent-dominated receiving rivers in Xi'an, China. Land use data, physical and chemical water quality parameters of surface and subsurface water were used as predictive variables, while the microbial respiratory electron transport system activity (ETSA), the Chao1 and Shannon index of total microbial community, as well as the Chao1 and Shannon index of denitrifying bacteria community were used as response variables, while ETSA was used as response variables indicating ecological processes and Shannon and Chao1 were utilized as parameters indicating microbial diversity. Two machine learning models were utilized to provide evidence-based information on how environmental factors interact and drive microbial activity and abundance in the HZ at variable depths. The models with Chao1 and Shannon as response variables exhibited excellent predictive performances (R2: 0.754–0.81 and 0.783–0.839). Dissolved organic nitrogen (DON) was the most important factor affecting the microbial functions, and an obvious threshold value of ∼2 mg/L was observed. Credible predictions of models with Chao1 and Shannon index of denitrifying bacteria community as response variables were detected (R2: 0.484–0.624 and 0.567–0.638), with soluble reactive phosphorus (SRP) being the key influencing factor. Fe (Ⅱ) was favorable in predicting denitrifying bacteria community. The ESTA model highlighted the importance of total nitrogen in the ecological health monitoring in HZ. These findings provide novel insights in predicting microbial activity and abundance in highly-impacted areas such as the HZ of effluent-dominated receiving rivers.

The relationship between healthy behavior and environmental sanitation with water quality in stunting occurrence work area of Sikabu Community Health Center Padang Pariaman

Stunting is a long-term nutritional deficiency from insufficient intake and recurrent infectious diseases. One of the factors that can influence stunting is the limited access to clean water. This research analyzes the relationship between healthy behavior and environmental sanitation with water quality in stunting occurrences. This is a quantitative descriptive study with a cross-sectional design. The population includes all mothers with stunted toddlers in the working area of Sikabu Community Health Center, Padang Pariaman Regency, totaling 49 individuals. The sampling technique employed was total sampling. Behavior and sanitation assessments were conducted using a questionnaire. Data collection took place from September 14 to 18, 2023. Microbiological parameters were evaluated using the Most Probable Number (MPN) method, while inorganic chemical parameters were assessed using spectrophotometry. Data processing involved Spearman rank statistical tests, where a p-value <0.05 was considered statistically significant. The research results indicate a significant relationship (p<0.05) between behavior and microbiological and inorganic chemical water quality parameters, with correlation coefficients of 0.745 and 0.604, respectively. There is a significant relationship (p<0.05) between sanitation and microbiological and inorganic chemical water quality parameters, with correlation coefficients of 0.658 and 0.520, respectively. This study concludes that there is a significant relationship between good behavior that has a positive impact on sanitation and drinking water quality on the level of stunting in the Sikabu Puskesmas working area of Padang Pariaman Regency with a correlation coefficient of (p<0.05).

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.

Effects of water quality on fish parasite biodiversity and physiological responses in the host fish Clarias gariepinus from a eutrophic lake subjected to acid mine drainage in South Africa.

Elevated concentrations of contaminants have negative impacts on aquatic organisms and their parasites. Changes in parasite infections have been proposed as a technique for monitoring the health of aquatic ecosystems. Furthermore, alterations in physiological responses (biomarkers) of organisms have also been used to delineate ecosystem quality. Lake Heritage is situated along the Crocodile River in Muldersdrift, Gauteng, South Africa, and is subject to contamination by acid mine drainage. Clarias gariepinus is a well-studied bioindicator species and host to numerous endoparasites and ectoparasites. The aims of this study were to delineate the health status of Lake Heritage through a multifaceted approach by comparing the water quality, biomarker responses, and parasite biodiversity of C. gariepinus, compared to unexposed laboratory-reared fish. Physical and chemical water quality parameters were determined using a hand-held probe, test kits, and element analysis with inductively coupled plasma-mass spectrometry. Biomarker responses in the gill, liver, and muscle tissues from C. gariepinus were assessed for total protein, metallothioneins, superoxide dismutase (SOD), and reduced glutathione (GSH) concentrations and activities of acetylcholinesterase and catalase. Results for water quality variables showed higher pH, nitrate, hardness, and copper levels compared with the South African Target Water Quality Guidelines. Catalase activity and concentrations of SOD and reduced GSH showed a response in C. gariepinus to the water quality. Ectoparasites had lower prevalence and mean intensity than endoparasites. However, there were no differences in the physiological responses between infected and uninfected hosts. The study shows that the eutrophic conditions in Lake Heritage cause biomarker responses in the host when compared to host fish in laboratory conditions. Integr Environ Assess Manag 2024;20:1539-1553. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Evaluating socio-cultural influences on the Nubui river quality and utilisation in Ghana

Clean water plays an important role in ensuring good public health and reducing health risks. To ensure population well-being, clear quality guidelines and standard limits are set to protect water re-sources. Drinking water should be free of microbial and chemical contamination, with water quality index values between 70 and 100. Despite meeting these standards, socio-cultural values deeply influence the relationship between rural communities and their water resources. Aesthetic, chemical and microbial water quality parameters including pH, turbidity, colour, TDS, nitrate and phosphate content, Escherichia coli and Salmonella levels were assessed; these parameters were used in computing water quality indices. Field observations were also done throughout the sampling season as water samples were assessed. Key informant interviews were conducted among ten purposively sampled community leaders, using an in-depth interview guide; the results were analysed using the interpretative phenomenological analysis method. Subsequently, a descriptive cross-sectional observational study involving 338 respondents was conducted to assess public perceptions regarding water quality, utilization types and socio-cultural influences. Water quality is compromised by run-off from riparian agricultural activities and domestic, coupled with seasonal aesthetic issues. Cultural norms and history influenced the

Effect of Water Storage Tank Material on Quality of Water with Storage Period

Quality drinking water is of prime importance for human need. Potable water comes from surface water and groundwater sources and it is acceptable for human consumption. The method of storing water plays a crucial role in maintaining its purity and safety for human consumption. Due to lack of continuous water supply, storage tanks are necessary to store water and storage tank material may affect the quality of potable water. The objective of this study is to investigate the variation in water quality during storage for some particular time period in different types of storage containers. 40 days (six weeks) is considered to determine potable water quality variation during storage in different container materials and materials used for containers are plastic tanks, clay pot and Reinforced Cement Concrete. To find the water quality parameters, samples are to be collected at five days interval. During the period of storage, physical, chemical and biological water quality parameters are to be determined. Parameters obtained from above tests are analyzed to understand the effect of age and container material on the quality of potable water. This analysis is useful to choose the material of storage container to store water for a particular period of time.

Biológiai vízminőségi paraméterek hatásainak vizsgálata a szarvasi Holt-Körösön

One of the essential natural resources is water resource in Hungary. It is threatened by many threats, both quantitative and qualitative. For these reasons, the protection of surface water and groundwater is a priority. The main objective of the present study is to determine which parameters have the greatest influence on the horizontal and vertical distribution patterns of phytoplankton in the water body. The study area is the Holt-Körös, which plays an important ecological, social, economic and recreational role in the region. Between the field and laboratory tests, the following physical, chemical and biological water quality parameters were investigated: water temperature, UV radiation index, Secchi depth, underwater light condition, dissolved oxygen content, suspended solids content, chlorophyll-a content, Fe, NO2-, NO3- NH4+, PO43-, Na+, K+, Mg2+, and pH value.

Analysis of Water Quality and Phagocytic Activity (Clarias Sp.) in Aquaponic and Non-Aquaponic Cultivation Systems

Catfish (Clarias sp.) is one of the many fishery biota that has animal protein which is much loved by Indonesian people. One way to develop environmentally friendly catfish cultivation is through the implementation of an aquaponic biofilter system. This research aims to analyze physical, chemical, and biological water quality parameters in catfish cultivation with and without aquaponics, to obtain a description of the non-specific immune system which is analyzed from the conditions of phagocytic activity of catfish cultivated with and without aquaponics. The method used is by taking samples ten times per week by taking water quality parameters as well as blood samples of catfish raised in ponds with and without aquaponics. The analysis used is the unpaired T-test. Based on the results obtained, it was concluded that all parameters showed that the aquaponic cultivation media was better compared to those without aquaponics.

Influence of runoff regulation on hydrochemical indicators of water in small rivers on the example of the Teplaya river in the Saratov region

Small rivers are extremely sensitive to any anthropogenic activity, including runoff regulation, and serve as a kind of indicator of the ecological state of natural complexes. In general, large rivers are well studied, and small water bodies are practically not studied, although they are of great economic importance. For Teplaya river of the Saratov region was given an ecological and geographical characteristic, sources of anthropogenic load on the reservoir were identified, an analysis was made of the degree of knowledge and background indicators of the rivers of this basin. On the example of Teplaya river effect of runoff regulation of a small river by a dam on a number of physical and chemical parameters of pond water quality is considered. It has been established that the water temperature in the Teplaya river in the autumn period before the runoff regulation was a constant value, and after the dam it increased to the last sampling point downstream. The hydrogen index varied within 7.5-8.4, the total mineralization of water consistently increased in the studied section of the river (0.66-1.08 g/dm3). It is shown that the content of ammonium ions and nitrites was much higher than the sanitary and hygienic standards, which indicates the uniform nature of fresh organic water pollution in this section of the river. An increase in the concentration of chlorides in the last of the cascade of ponds was established - almost 1.5 times compared to the higher sampling points, which, however, did not exceed the standard values.

Comparison of COD Determination Methods FAS Titrimetric with UV-Vis Spectrophotometry

Liquid waste is one of the factors causing contamination of the aquatic environment. One of the chemical parameters of water quality namely Chemical Oxygen Demand (COD). This research was conducted at three different concentration levels, namely low, medium, and high, with samples of river water, domestic wastewater, and sago liquid waste. The method used is UV-Vis spectrophotometry (SNI 6989.2: 2019) and FAS titrimetry (APHA, 2017 methods 5220 D); for the UV-Vis spectrophotometry method in the range 90 mg/L, the wavelength was measured at 420 nm, while for high levels in the range 100 mg/L x 900 mg/L, it was measured at 600 nm. The quality control parameters used are accuracy and precision parameters. The purpose of this study was to compare the COD determination between UV-vis spectrophotometry and FAS titrimetry and to determine the validity and correlation of the two methods—a comparison of the results of the two methods used in the F test. The results showed that the COD values from UV visible spectrophotometry and FAS titrimetry yielded good precision and accuracy values and met the acceptable limits, namely %RSD 10% and 90% accuracy %R 110%. However, the results of the COD analysis using the UV-Vis spectrophotometry method were lower by 0.8556 than the results of the COD analysis using the FAS titration method, with a correlation coefficient r2 = 0.982. The average concentration of UV-Vis spectrophotometry in samples of sago wastewater was 572.141 mg/L, domestic wastewater was 113.525 mg/L, and river water was 42.98 mg/L. The average COD level of the titrimetric method in sago wastewater was 641.888 mg/L, domestic wastewater was 219.251 mg/L, and river water was 58.016 mg/L. The results of the F test for these two methods produce an Fcount Ftable. The null hypothesis (Ho) is rejected, meaning there is a significant difference between the two methods.

Invasive species interactions affect nutrient cycling in a shallow reservoir: a mesocosm experiment

Shivers SD, Golladay SW, Waters MN, Wilde SB, Marzolf NS, Covich AP. 2023. Invasive species interactions affect nutrient cycling in a shallow reservoir: a mesocosm experiment. Lake Reserv Manage. 39:278–290.Nonnative species’ introductions can affect nutrient dynamics as new combinations of species form novel ecosystems. This experiment investigated how combinations of 3 invasive species, one submerged macrophyte (Hydrilla) and 2 benthic invertebrates (Corbicula and Pomacea), affected nutrient cycling in a shallow reservoir, Lake Seminole, Georgia, United States. To assess these effects, an in-reservoir mesocosm array was installed using different combinations of the invasive species. Eight physical and chemical parameters of water quality were measured in all the mesocosms (1 control, 7 treatments) weekly for the duration of the 5 wk experiment. Nitrogenous compounds were strongly affected by Hydrilla and Pomacea presence, with NO3-N concentrations decreasing in Hydrilla mesocosms and NH4-N and total nitrogen (TN) increasing in Pomacea mesocosms. Corbicula, when present, helped to mitigate increases in N concentrations, presumably as filter feeding reduced water column TN concentration. Overall, Hydrilla growth reduced inorganic N concentration. Pomacea grazing converted stored N to available organic and particulate N. Total phosphorus concentrations were not impacted by the invasive species treatments and increased in all mesocosms during the experiment. In short, Hydrilla and Corbicula are contributing to the uptake, conversion, and sequestration of nutrients that may increase eutrophication, while Pomacea is releasing potentially eutrophying nutrients. As climate change and human influence continue to create new combinations of species, it is important to understand the effects produced by novel combinations of species.