Turbidity Research Articles

Design and Implementation of a Microcontroller-Based Water Turbidity Detector Utilizing the Nephelometric Turbidity Unit Method

The objective of this study is to create a water turbidity detection system, aiding customers of a municipal water supply company in preserving the quality of water for everyday use. The aim is to prevent the mingling of stored clean water with turbid water when the tap is turned on. To achieve this, we employ a smartphone as a remote control device, enabling users to monitor the water's condition remotely. The study's findings demonstrate that this system adeptly manages the water separation process based on its condition, allowing manual control via Bluetooth communication within a maximum range of 10 meters. This setup provides two control options: activating and deactivating the water channel through a solenoid valve. Test outcomes indicate the system effectively segregates the water as per its condition and promptly follows user directives.

Monitoring and evaluation of the water quality of the Lower Neches River, Texas, USA

Increasing bacteria levels in the Lower Neches River caused by Hurricane Harvey has been of a serious concern. This study is to analyze the historical water sampling measurements and real-time water quality data collected with wireless sensors to monitor and evaluate water quality under different hydrological and hydraulic conditions. The statistical and Pearson correlation analysis on historical water samples determines that alkalinity, chloride, hardness, conductivity, and pH are highly correlated, and they decrease with increasing flow rate due to dilution. The flow rate has positive correlations with Escherichia coli, total suspended solids, and turbidity, which demonstrates that runoff is one of the causes of the elevated bacteria and sediment loadings in the river. The correlation between E. coli and turbidity indicates that turbidity greater than 45 nephelometric turbidity units in the Neches River can serve as a proxy for E. coli to indicate the bacterial outbreak. A series of statistical tools and an innovative two-layer data smoothing filter are developed to detect outliers, fill missing values, and filter spikes of the sensor measurements. The correlation analysis on the sensor data illustrates that the elevated sediment/bacteria/algae in the river is either caused by the first flush rain and heavy rain events in December to March or practices of land use and land cover. Therefore, utilizing sensor measurements along with rainfall and discharge data is recommended to monitor and evaluate water quality, then in turn to provide early alerts on water resources management decisions.

Y-site injection physical compatibility of remdesivir with select intravenous drugs used in palliative care and for treating coronavirus disease 2019.

No compatibility tests are available for remdesivir other than 0.9% sodium chloride. In this study, we aimed to evaluate the physical compatibility of remdesivir with drugs used in palliative care and COVID-19 treatment. Remdesivir was tested for compatibility with 10 different drugs (fentanyl, morphine, hydromorphone, oxycodone, heparin, furosemide, octreotide, acetated Ringer's injection, 2-in-1 peripheral parenteral nutrition, and 2-in-1 total parenteral nutrition). Remdesivir was formulated to a final concentration of 1 mg/mL, and the other drugs were prepared at clinical concentrations. Three test solutions were used for compatibility testing, with remdesivir and the target drugs compounded in a 1:1 ratio. Appearance measurements, including Tyndall effect, turbidity, and pH, were performed immediately after mixing and at 1 h and 4 h after mixing. Changes in appearance, including the Tyndall effect, turbidity (turbidity change of ≥ 0.5 nephelometric turbidity unit [NTU] based on control solution for each test drug), and pH (a change of ≥ 10% based on the pH immediately after mixing) were used to determine physical compatibility. All the drugs tested were compatible with remdesivir. The combination of remdesivir and furosemide produced the highest turbidity (0.23 ± 0.03 NTU) 1 h after mixing. The lowest and highest pH values were observed at 4 h after mixing for the combinations of remdesivir and morphine (3.23 ± 0.02) and remdesivir and furosemide (8.81 ± 0.06). The drugs tested in this study show Y-site physical compatibility with remdesivir.

Estimation of Water Quality Parameters in Oligotrophic Coastal Waters Using Uncrewed-Aerial-Vehicle-Obtained Hyperspectral Data

Water quality monitoring in coastal areas and estuaries poses significant challenges due to the intricate interplay of hydrodynamic, chemical, and biological processes, regardless of the chosen monitoring methods. In this study, we analyzed the applicability of different monitoring sources using in situ data, uncrewed-aerial-vehicle (UAV)-mounted hyperspectral sensing, and Sentinel-2-based multispectral imagery. In the first part of the study, we evaluated the applicability of existing empirical algorithms for water quality (WQ) parameter retrieval using hyperspectral, simulated multispectral, and satellite multispectral datasets and in situ measurements. In particular, we focused on three optically active WQ parameters: chlorophyll a (Chl,a), turbidity (TUR), and colored dissolved organic matter (CDOM) in oligotrophic coastal waters. We observed that most existing algorithms performed poorly when applied to different reflectance datasets, similar to previous findings in small and optically complex water bodies. Hence, we proposed a novel set of locally based empirical algorithms tailored for determining water quality parameters, which constituted the second part of our study. The newly developed regression-based algorithms utilized all possible combinations of spectral bands derived from UAV-generated hyperspectral data and exhibited coefficients of determination exceeding 0.9 for the three considered WQ parameters. The presented two-part approach was demonstrated in the semi-enclosed area of Kaštela Bay and the Jadro River estuary in the Central Eastern Adriatic Sea. This study introduces a promising and efficient screening method for UAV-based water quality monitoring in coastal areas worldwide. Such an approach may support decision-making processes related to coastal management and ultimately contribute to the conservation of coastal water ecosystems.

The Impact of Construction Activities Near the Gulf: The Likelihood of Construction Materials Effect, ERA and Sustainable Development

The environmental risks associated with construction activities are being monitored, especially given the global construction boom, in which the United Arab Emirates is a major participant. Construction activities near Gulf water cause variations in the ecosystem, yet whilst the Environmental Protection Agency (EPA) has given much attention to environmental risks resulting from construction material during construction activities to streams and rivers, there has been limited exploration of those risks in the Gulf. This research paper aims to identify the best practices in Environmental Risk Assessment (ERA) in order to contribute towards the achievement of sustainable development. Specifically, the objective is to determine the relationship between the parameters of water quality (turbidity and pH) that affect the ecosystem during construction activities in the hot summer and to frame effective ERA, to pursue this aim, 32 water samples were collected from the Gulf water in two locations; the first adjacent by 12 m to the Gulf and at a 500 m distance from the second, inactive location in Abu Dhabi city, UAE. All these water samples were taken during the peak time of construction activities, and after six hours of no activities, taking into consideration the weather conditions. Samples were tested in the environmental laboratory within 24 hours. The temperature is particularly considered to predict future levels of variation and consider risks that will affect such areas and seasons. The results indicate that a maximum turbidity level of 25.2 NTU (Nephelometric Turbidity Units) was noticed when the temperature was 43°C and pH 5.9 at the active construction. Hence a strong relationship between turbidity, pH, and temperature and their impacts on the water quality of the Gulf during construction activities is revealed. Outcomes are promising in effective risk management for sustainable development of the Gulf ecosystem during construction activities. The study demonstrates the need for a successful risk management framework to focus on the construction material management treatment that can decrease turbidity and adjust pH in the Gulf water near active construction. In addition, managing statistics of the communities residing near the Gulf and re-evaluating environmental risks are crucial.

Rancang Bangun Water Change Otomatis Berdasarkan Kekeruhan Air pada Aquarium dengan Penerapan Internet of Things (IoT) Berbasis Android

Recently, maintaining ornamental fish has become a hobby in society, from the lower classes to the upper classes. Draining and filling water in the existing aquarium is still done manually. Many people like to keep fish confused if they travel far. No one may maintain fish properly. So, worrying about regular water changes. An important factor in keeping fish is the level of turbidity of the water. The turbidity level of water that can be tolerated by warm water fish is 25NTU (Nephelometric Turbidity Unit). So based on the above considerations, the researcher tried to submit a research proposal with the title "Design of Automatic Water Change Based on Water Turbidity in Aquariums with the Application of Android-Based Internet of Things (IoT). The developed system is expected to be able to maintain the level of water turbidity and replace water automatically in the aquarium so that it can increase the life expectancy of fish. The results of this study are that this system can effectively reduce the turbidity value of water in the aquarium. After being tested 10 times the system can keep the water turbidity level below the value that can be tolerated by warm water fish (25NTU).

Physical compatibility of sulbactam/durlobactam with select intravenous drugs during simulated Y-site administration.

Sulbactam/durlobactam is a combination antibiotic designed to target Acinetobacter baumannii, including carbapenem-resistant and multidrug-resistant strains. The objective of this study was to determine the physical compatibility of sulbactam/durlobactam solution during simulated Y-site administration with 95 intravenous (IV) drugs. Vials of sulbactam/durlobactam solution were diluted in 0.9% sodium chloride injection to a volume of 100 mL (the final concentration of both drugs was 15 mg/mL). All other IV drugs were reconstituted according to the manufacturer's recommendations and diluted with 0.9% sodium chloride injection to the upper range of concentrations used clinically or tested undiluted as intended for administration. Y-site conditions were simulated by mixing 5 mL of sulbactam/durlobactam with 5 mL of the tested drug solutions in a 1:1 ratio. Solutions were inspected for physical characteristics (clarity, color, and Tyndall effect), turbidity, and pH changes before admixture, immediately post admixture, and over 4 hours. Incompatibility was defined as any observed precipitation, significant color change, positive Tyndall test, or turbidity change of ≥0.5 nephelometric turbidity unit during the observation period. Sulbactam/durlobactam was physically compatible with 38 out of 42 antimicrobials tested (90.5%) and compatible overall with 86 of 95 drugs tested (90.5%). Incompatibility was observed with albumin, amiodarone hydrochloride, ceftaroline fosamil, ciprofloxacin, daptomycin, levofloxacin, phenytoin sodium, vecuronium, and propofol. The Y-site compatibility of sulbactam/durlobactam with 95 IV drugs was described. These compatibility data will assist pharmacists and nurses to safely coordinate administration of IV medications with sulbactam/durlobactam.

Underwater Wireless Video Communication Using Blue Light

Interest in wireless blue light communication is increasing because this technology shows promise for realizing high-speed, long-distance and full-duplex underwater communication. Here, we demonstrate an underwater wireless communication system, OceanLink, to establish full-duplex data transmission using blue light. Both the transmitter and receiver are housed together to independently transmit and receive data simultaneously. To obtain a longer transmission distance and better light field distribution, the transmitter is composed of an array of three light-emitting diode (LED) units with the dominant emission peak wavelength centered around 452 nm, each of which merges four LEDs in series. These LEDs are synchronously driven via a main processing unit to pulse blue light using a nonreturn-to-zero on-off keying modulation scheme. At the receiver, light passes through a neutral density (ND) filter and a focus lens to hit the transducer, which converts light signals into electrical signals. The waterproof OceanLink achieves a bidirectional communication rate of 4 Mbps with a wireless transmission distance of 12 m in a swimming pool, wherein the ND factor is 256 and the nephelometric turbidity unit is 1.7. Thus, real-time full-duplex underwater video communication is experimentally demonstrated.

Separation of nanoplastics from synthetic and industrial wastewater using electrolysis-assisted flotation approach: A green approach for real-time contaminant mitigation

Nanoplastics pose a significant global environmental concern, as they can accumulate emerging pollutants and enter the food chain, endangering human health and ecosystems. Wastewater treatment plants (WWTPs) have been identified as the primary source of micro and nanoplastic contamination, necessitating the development of effective removal methods. This study investigates the efficacy of electrolysis-assisted flotation (EF) process for removing nanoplastics from synthetic wastewater, using polystyrene-type nanoparticles synthesized from expanded polystyrene waste (EPS) as representative nanoplastic contaminants. Electrolysis experiments were conducted using parallel aluminium electrodes under low-voltage conditions. The study systematically explores the influence of various process parameters, including electrode spacing, salt concentration, nanoplastics concentration, and applied voltage, on the removal efficiency of nanoplastics. The removal efficiency was evaluated using a turbidity meter and dynamic light scattering technique. The derived count rate (DCR) obtained from dynamic light scattering supplements the nephelometric turbidity units (NTU) and provides a reliable estimate of the nanoplastics sample concentration. Under optimized conditions, with a specified electrolyte concentration and pH of 7.2 ± 0.3, the EF process achieved an impressive removal efficiency of nearly 95 % (94 % per DCR). A notable advantage of the proposed method is forming a foamy layer on top of the reactor when nanoplastics and coagulants are mixed, facilitating easy removal by simple scraping. This study provides valuable insights into developing an eco-friendly and sustainable approach for the large-scale removal of nanoplastics. The results contribute to advancing wastewater treatment strategies and addressing the pressing issue of nanoplastic pollution.

Water turbidity affects the establishment of Neochetina eichhorniae (Warner) (Coleoptera: Curculionidae): Implications for biological control of water hyacinth

Water hyacinth is the target of nine biological control agents in South Africa including Neochetina eichhorniae (Warner) and Neochetina bruchi (Hustache) (Coleoptera: Curculionidae). These two weevils have also been released against water hyacinth in Rwanda, but failed to control the weed invasion, possibly due to high turbidity in the country's water bodies. This study therefore aimed to investigate the effect of water turbidity on the establishment and performance of N. eichhorniae in Rwanda. Turbidity levels were measured over two seasons in four Rwandan rivers and two lakes. The results were then used to benchmark laboratory trials to test the effect of turbidity on the weevils' development. Water hyacinth plants were maintained at four turbidity levels: Clear water (2 Nephelometric Turbidity Units (NTU): low (85 NTU), medium (600 NTU) and high (1500 NTU). Each treatment plant was inoculated with three N. eichhorniae larvae, while control plants were free of larvae. Plant growth was measured weekly for three months, while adult weevil emergence was recorded from the 56th day of the experiment. The number of adults emerging from the treatment plants grown in the clear water, low, medium and high turbidity levels were 24, 21, 12 and 0, respectively. Larval feeding was greater on plants growing in clear water and the low turbidity, compared to the medium and high turbidity treatments. These results indicate that N. eichhorniae may not establish or perform well in water bodies with high levels of turbidity, which in turn enhances the growth of water hyacinth, allowing compensatory growth for weevil feeding.

Monitoring of sea surface temperature, chlorophyll, and turbidity in Tunisian waters from 2005 to 2020 using MODIS imagery and the Google Earth Engine

Time series ocean color data product facilitates the study of spatio-temporal variability of various physical parameters of water, which allows the monitoring of water quality, interannual variability in phytoplankton biomass, and seasonal representation at different latitudes.Its role in marine biogeochemistry, water quality distribution, and climate fluctuation is very crucial., However, the lack of in situ measurement induces poor management and knowledge of the dynamics of Tunisian coastal waters. Therefore, this study aims to develop a workflow to monitor Tunisian waters based on long-term spatial observations of sea surface temperature, chlorophyll, and turbidity observations.Long-term sea surface observations were automatically obtained by processing the daily Moderate-resolution Imaging Spectroradiometer (MODIS) Aqua data via the Google Earth Engine (GEE) platform from 2005 to 2020. The recorded average monthly and yearly trends are validated by point-based measurements from the Gulf of Gabes and a qualitative analysis based on the bibliographic synthesis of offshore measurement campaigns in Tunisian waters. The hottest years were 2006, 2007, and 2017 while the coldest ones (12–28 °C) were 2011, 2012, and 2016. The highest chlorophyll content (10 and 5 μg L-1) was observed in 2006, 2007, 2011, 2012, 2015, 2016, and 2019. In addition, Turbidity peaks ranging between 11 nephelometric turbidity units (NTU) and 5 NTU were identified during December and January of 2005 2008, and 2011. Moreover, seasonal cyclicity and high correlations between estimated parameters were observed. Overall, combining the Google Earth Engine tool with daily MODIS data was effective for the routine monitoring of water quality parameters that is fast, accurate, and important for Tunisian coast management.

A novel sinusoidal design for an electrocoagulation reactor followed by an electro-Fenton reaction and a porous ceramic filter for the treatment of polluted waters.

In this research work, a novel design of an electro-Fenton reactor for the treatment of polluted water was investigated. In addition to the reactor with iron electrodes, a ceramic filter was also used. An electrical circuit was designed to change the cathodes and anodes every 24 s via an electrical relay between the electrodes. The untreated water was sucked into the reactor with an air pump and entered the electrocoagulation chamber after filtration with a ceramic filter. Then, it flows to the polyethylene filter to separate the coagulated particles from the fresh water. To produce 12 L of clean water, the system consumed 100 W of energy. Analysis of a river sample showed a reduction in nephelometric turbidity units (NTUs), total suspended solids (TSS), biochemical oxygen demand (BOD), and chemical oxygen demand (COD). Turbidity reduction studies have shown that the system can improve water transparency by 95%, thereby improving water quality to acceptable levels. Further, this system reduced TSS by more than 86%. In addition, BOD was reduced by more than 84% and COD by more than 88%, as shown by the change in the ratio of BOD to COD from 0.44 to 0.625, indicating improved water quality. According to the results, the treatment system can clean polluted waters, particularly during floods and when industries discharge their effluents into rivers.

Viability of two adaptive fuzzy systems based on fuzzy c means and subtractive clustering methods for modeling Cadmium in groundwater resources

The Adaptive Neuro-Fuzzy Inference System (ANFIS) combines the strengths of both Artificial Neural Networks (ANNs) and Fuzzy Logic (FL) into a single framework. By doing so, it allows for quicker learning and adaptable interpretation capabilities, which are useful for modeling complex patterns and identifying nonlinear relationships. One significant challenge in assessing water quality is the difficulty and time-consuming nature of determining the various factors that impact it. Given this situation, predicting heavy metal levels in groundwater resources, both urban and rural, is essential. This paper investigates two methods, ANFIS-FCM and ANFIS-SUB, to determine their effectiveness in modeling Cadmium (Cd) in groundwater resources. ‏The parameters to be considered are: dissolved solids (TDS), electroconductivity (EC), turbidity (TU), and pH were assumed to be the independent variables. A total of 51 sampling location were used with in the groundwater resource were used to develop the fuzzy models. For evaluating the performance of ANFIS-FCM and ANFIS-SUB models, three different performance criteria including the correlation coefficient, root mean square error, and sum square error were used for comparing the model outputs with actual outputs‏.‏ Based on the obtained results from scatter plots of actual and predicted value by ANFIS-SUB and ANFIS- FCM models, the determination coefficient (R2) value for total data, test and train sets is equal to 0.978, 0.982, 0.993 and to 0.983, 0.999 and 0.998 respectively. This result proved the Cd predictions of the implemented ANFIS-FCM model was significantly close to the measured all experimental data with R2 of 0.983. The performance of the implemented ANFIS-FCM model was compared with the ANFIS-SUB model and it is found that the ANFIS-FCM provided slightly higher accuracy than the ANFIS-SUB model. Also, the results obtained from the comparison between the predicted and the actual data indicated that the ANFIS-FCM and ANFIS-SUB have a strong potential in estimating the heavy metals in the groundwater with a high degree of accuracy.

Nitrate Measurement in Seawater Based on Environmental Correction Algorithm

The accuracy of the in-situ nitrate measurement in seawater is affected by many environmental factors, such as salinity, temperature, and turbidity. Along these lines, in this work, an environmental correction (including salinity, temperature, and turbidity) algorithm was proposed and experimentally verified, demonstrating a good prediction accuracy of the nitrate concentration. The orthogonal projections to latent structures (OPLS) algorithm was used for performing one-time turbidity and temperature correction of the acquired spectral data. After the environmental correction, the support vector machine (SVM) was used to establish the nitrate calculation model. The OPLS-SVM algorithm was systematically examined in spiked samples with four different groups of seawater matrices (the seawater samples from Western Pacific, Aoshan Bay of Qingdao, China, South China Sea, and Yellow Sea with addition of various nitrate concentrations and turbidity). From the extracted results, it was proven that the SVM calculation model with the OPLS correction algorithm could significantly improve the accuracy of the nitrate measurement. More specifically, a prediction performance with root mean square error (RMSE) of 0.22 μmol/L and R <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> of 0.999 was demonstrated when the temperature and turbidity ranges were 5-25 °C and 0-50 NTU (nephelometric turbidity unit), respectively. The introduced method is suitable for measuring the nitrate concentration in turbidity seawater with a high degree of accuracy, which is undoubtedly of great importance for performing in-situ nitrate measurement in complex seawater environments.

A novel framework for turbidity source apportionment of the urban lakeside river network

Turbidity source apportionment is essential but complex for precise environmental rehabilitation of worldwide urban lakeside river networks impaired by turbidity. A new turbidity source analysis framework including in-situ sampling, vessel monitoring, remote sensing, and hydrodynamic modelling was proposed, where the critical processes of flow reversal from the turbid lake, navigation, and urban non-point source in urban lakeside river networks were explicitly considered. The case study results showed that the turbidity problem (mean value was 211.3 nephelometricturbidityunits (NTU)) was primarily led by suspended inorganic matter (58%), followed by suspended organic matter (19%) and other matter. The Tiaoxi River and busy shipping contributed most to the annual total suspended solids load of the target river, with the same percentage of 34%. The turbid Lake Taihu provided 64,663 tonnes and 31% of the total suspended solids load, focusing on the autumn and winter months. Tiaoxi River load was highly concentrated on the storm events, which accounted for 71.4% of the annual Tiaoxi River source (209846 tonnes). The large water volume of reverse flow and the high TSS concentration of Lake Taihu in the autumn and winter months accounted for the seasonal change in Lake Taihu’s TSS load. The coronavirus disease lockdown reduced the mean monthly total suspended solids concentration of 152.4 mg/L in November and December 2019 to 49.2 mg/L in January and February 2020, by limiting the waterway transportation and the market demand for building materials. The river estuary’s vegetation interception belt, shipping restriction and rerouting, and integrated catchment management were advised to mitigate the urban river network turbidity.

Fuzzy Inference System in Assessing the Improved Wastewater Quality for Irrigation through Sedimentation, Dilution, and Biochar Filtration in Sulaymaniyah City, Iraq

The study aims to improve the quality of wastewater in Sulaymaniyah city, Iraq, which has been facing drought problems, by using sedimentation, dilution (1:1), and biochar filtration. It provides an alternative source of water for agriculture, addressing the water shortage problem in the region. The irrigation water quality is evaluated based on the Water Quality Index (WQI) using a fuzzy inference system, a mathematical tool that converts complex statements into mathematical terms and simplifies them into outputs. The centroid defuzzification technique is applied to convert the fuzzy results into crisp numbers. The output of the FIS score is used to determine the suitability of water for irrigation. The study utilized six different samples: groundwater (GW), wastewater (WW), sedimented wastewater (SW), filtered sedimented wastewater (FSW), diluted sedimented wastewater (DSW), and filtered diluted sedimented wastewater (FDSW). The samples were analyzed for their physical and chemical properties, including pH, electrical conductivity (EC), total suspended solids (TSS), turbidity (TUR), total nitrogen (TN), total phosphate (TP), cations (Ca, Na), anions (Cl and SO4), and heavy metals (Mn, Fe, Co, Ni, Zn, Cu). The study found that the WQI FIS-I values for wastewater increased with each treatment step, with the final step of passing the DSW through a biochar filter resulting in an FIS WQI-I value of 61.59, indicating good water quality. The deterministic method also showed improved levels for TP, TN, TSS, and turbidity. Mean TN and TP values decreased to 8.9 mg L-1 and 3.62 mg L-1, respectively, in the FDSW, with turbidity and TSS also decreasing to 0.37 NTU and 21 mg L-1. The resulting FDSW was of the best quality among the treated waters, making it suitable for drip irrigation.

Evaluation of the Performance of the Makhmuor Villages Water Filtration Plant in Nineveh Governorate / Iraq

The current study was conducted to evaluate the performance of the Makhmuor villages water filtration plant and to ensure the validity of the water produced and delivered to the consumer. The physical, chemical and biological properties of the Tigris River water at the intake of the plant and at different stages of the plant and the water reaching the residential areas benefiting from the plant were studied. The studied samples were collected for a period of five months, monthly from July to November 2022. Temperature, electrical conductivity, total dissolved solids, turbidity, dissolved oxygen, biological oxygen demand, total alkalinity, total hardness, calcium, magnesium, chloride, sulfates, phosphates, nitrates, pH, residual chlorine, and the total number of bacteria. And the total number of coli bacteria and the number of plankton. The results of the study showed that many samples conformed to the Iraqi and international specifications for drinking water, except for turbidity, as it exceeded the permissible limit in most samples, which is less than 5 (Nephelometric Turbidity Unit) NTU, and dissolved oxygen reached 4.4 and 4.8 mg / liter in the Tigris River for the month of August and water Liquefaction in the villages for the months of July and September, respectively, as well as 4.4 mg/L in the automated sedimentation and filtration ponds and the village 2 for the month of November. The biological requirement for oxygen in seven samples in different locations for the months of October, August and November was 0.1 mg/L and the highest value was 6.4 mg/L in basin 2 in October. And nitrates were in low concentrations. As for residual chlorine, all tests were free of any percentage of it, except for the month of November, when it was in the plant tank 2 mg / liter and in the two villages 0.3 mg / liter. Thus, the number of bacteria increased and appeared in all samples throughout the study period.

Evaluation of the Antimicrobial Efficacy of Triphala, Aloe Vera, and Morinda Citrifolia (M. Citrifolia) as Potential Root Canal Irrigants and their Effectiveness in Decontaminating Gutta-Percha Cones: An In vitro Disk Diffusion and Digital Photo-Colorimeter-Based Study

Context and Aim: A plethora of chemicals have been used for gutta-percha decontamination, though none of these methods have proven to be fully effective. The aim of this study was to evaluate the antimicrobial efficacy of triphala, aloe vera, and Morinda citrifolia (M. citrifolia) as potential root canal irrigants and their effectiveness in decontaminating gutta-percha cones against Escherichia coli (E. coli), Escherichia faecalis (E. faecalis), and Staphylococcus aureus (S. aureus). Materials and Methods: The antimicrobial efficacy of different herbal extracts against the reference strains of the test pathogens was assessed based on the zones of inhibition created, while for testing decontamination of gutta-percha cones, sterile gutta-percha cones were incubated in thioglycollate broth (THIO) followed by the evaluation of the turbidity values of the broth (in formazin turbidity units (FTU)) through digital photo-colorimeter. Statistical Analysis Used: One-way analysis of variance (ANOVA) and Fisher's least significant difference (LSD) post hoc analysis were used for comparison between different groups. P &lt;0.05 was considered statistically significant. Results: The results of this study revealed that for E. faecalis and E. coli, 90% ethanolic extracts of aloe vera had maximum efficacy with the diameter of the zone of inhibition achieved being 23.0 mm and 17.0 mm, respectively, while for S. aureus, both aloe vera and M. citrifolia showed equal zones of inhibition of diameter of 22.0 mm at 10-1 concentration. Conclusions: The results obtained in this study suggested that all three tested herbal extracts were found to have optimal antimicrobial activity against the test pathogens.

Optimum conditions for high-speed solid-liquid separation by ballasted flocculation.

In the ballasted flocculation, high-speed sedimentation of suspensions is achieved using a microsand as a ballast material and a polymer flocculant combined with microflocs made of polyaluminum chloride (PAC) as an inorganic coagulant. In this study, three turbid water samples containing kaolin clay (kaolin concentration: 20, 200, and 500 mg/L) were treated by coagulation-sedimentation and ballasted flocculation. The effects of pH and PAC dosage, which are the controlling parameters for coagulation, and the microsand (silica sand) and polymer dosages, which are the controlling parameters for ballasted treatment, on the treatment efficiency and floc settling velocity were examined. The floc settling velocity under the optimum conditions was 17 times higher than that of the conventional coagulation-sedimentation process using PAC. The turbidity was 0.54 turbidity unit (TU) (TU as the kaolin standard), and its removal efficiency was 99.7%. Furthermore, turbid water samples with different kaolin concentrations (20 and 500 mg/L) were treated via the ballasted flocculation. In this study, fundamental information on the optimization of each dosage condition of coagulant, ballast, and polymer and pH condition in ballasted flocculation was obtained, and the removal mechanisms under optimal, underoptimistic and overoptimistic conditions were proposed.

Synchronism of sediment erosion and deposition processes during high-turbidity events in a large shallow lake

High-turbidity events (HTEs) frequently occur in shallow lakes and can deeply influence lake ecosystems. However, the processes of sediment erosion and deposition are not fully understood. To investigate these processes, two investigative campaigns that integrate bed sediment measurements, sediment settling experiments, in-situ observations, or a hydrodynamics-sediment model were conducted to quantitatively study wind-induced HTEs in Lake Taihu, China. Cohesive sediments were massively entrained from the lakebed by wind waves when the wind speed exceeded its critical value of 7 m s−1, as estimated by water depth, triggering HTEs with turbidity waves of > 100 nephelometric turbidity units. The suspended sediment concentration was the net sediment flux of erosion (average: 5.9 mg m−2 s−1) and deposition (average: 5.5 mg m−2 s−1), which occurred synchronously for most of the HTEs and resulted in high temporal variation in suspended sediment concentration. This synchronism was determined by the critical erosional stress of lakebed sediments, which was spatially heterogeneous (0.017–0.055 N m−2) in a large lake. Equations for erosion and deposition processes were derived following the investigative campaigns and used to develop a cohesive sediment transport model for simulating HTEs in Lake Taihu. Simulations indicate that the synchronism of sediment erosion and deposition led to a near-lakebed turbid water layer during an HTE, which sustained the sediment lutocline in Lake Taihu. Further investigation should be conducted on the role of the near-lakebed turbid water layer during endogenous pollution in large eutrophic lakes.