Characterisation of Microplastics from the Effluent of a Municipal Wastewater Treatment Plant and from its Natural Receptor

Results obtained from the characterization of three water samples (one representing the effluent of a municipal treatment plant and the two others representing surface water from the Jiu River/Romania, upstream and downstream of the effluent discharge point) are presented in this study in terms of microplastic content. The water samples were processed by successively passing them through a series of filters with the following dimensions: 5 mm, 0.5 mm (500 im), 0.1 mm (100 im) and then through some microfiltration membranes (MF) type EZ-Pak Membrane Filters (Merk-Millipore) made of a mixture of cellulose esters, with an average pore diameter of 0.45�m. In order to highlight the microplastics in the water samples, their analysis was performed as well as the solid material retained on the microfiltration membranes, by scanning electron microscopy (SEM) using a SEM Quanta FEG 250/Thermo Fischer Scientific. The results obtained highlighted the existence of microplastics in all the analyzed samples, in the known forms presented in the specialized literature: irregular planes, fibers and spheres. Their dimensions are variable, ranging between 3.2 �m and 119.5 �m for irregular plane microplastics and between 3 �m and 15 �m for spherical microplastics. The dimensions of microplastics in the form of fibers are also in the range of tens of �m and cannot be established exactly because in most cases they appear in the form of conglomerates. The treatment plant�s microplastic effluents content led to the modification of the physical-chemical indicators of the water in their natural receptor. Thus, the content of organic matter and total suspended matter in the downstream water compared to the effluent discharge point is higher than in the upstream water. The analysis of microplastics by SEM allows only their highlighting and their geometry, being a first step in the study of the pollution induced by such materials.

Design and Development of Ram Pump

Due to A hydraulic ram (or water ram) pump is a simple, motorless device for pumping water at low flow rates. It uses the energy of flowing water to lift water from a stream, pond, or spring to an elevated storage tank or to a discharge point. It is suitable for use where small quantities of water are required and power supplies are limited, such as for household, garden, or livestock water supply. A hydraulic ram pump is useful where the water source flows constantly and the usable fall from the water source to the pump location is at least 3 feet.

ASSESSMENT OF HOSPITAL WASTEWATER QUALITY AND MANAGEMENT IN BAB-AL MUADHAM REGION AT BAGHDAD

The Tigris River is the most important source of water in Iraq; however, it suffers from the impact of pollutants that disposal directly into it. In this study, the Water Quality Index (WQI) of 7 of the chemical properties (Cl-, NO3, SO4, COD, BOD5, Ca, Mg) in the Tigris River, Baghdad, Iraq was analyzed to measure the impact of liquid waste discharge in the city of medicine on the river from January to October 2020. Three points were selected as the sample location, the first point was 700 meters before the discharge point, the second point was the discharge point, and the third point was 400 meters after the discharge point. The findings revealed that the concentration of all the measured components at the region where the sanitary discharge point site2 was situated was much higher than that of the location before the sanitary discharge point site1. For example, in January Cl- the concentration at site1 was (350 mg/l) relative to site2 the concentration at (1200 mg/l). In comparison, the concentration of the constituents in the area after the sanitary discharge point site 3 was lower than that of the sanitary discharge point area site2. In addition, Cl- concentration at site3 was (750 mg/l) lower than site2 (1200 mg/l) but still higher than site1 (350 mg/l). The lower concentration at site3 suggests that the water body of the river is being diluted; however, this is not a solution as the causes of pollutants of the river are various. Most of the findings have shown that the permissible cap for the Iraqi standards and the World Health Organization (WHO) for the river maintenance system has been surpassed.

Impacts of wastewater discharge from Kalar city on Diyala-Sirwan river water quality, Iraq: pollution evaluation, health risks of heavy metals contamination

In this work, a comprehensive assessment has been performed to understand impact of wastewater discharge from Kalar city on water quality parameters of Diyala-Sirwan river, Iraq. Levels of physicochemical parameters of Ca, K, Na, Mg, pH, electrical conductivity, dissolved oxygen, total dissolved solid, turbidity, biological oxygen demand, and total hardness, and heavy metals of Fe, Mn, Ni, Cu, Zn, Hg, Al, Ba, Se, and As have been determined by inductively coupled plasma optical emission spectroscopy and other devices. Pollution indices, health risk assessment, and multivariate analysis have been applied to evaluate pollution intensity originated from wastewater discharge on river water quality at different locations, before and after the impact point. Pollution levels of slight to moderate have been identified using different indices for the river water at all sampling locations after the wastewater discharge point. Cluster and correlation analyses showed that the impact of wastewater discharge on the river water quality was occurring along the river within the study area. Non-carcinogenic health risk assessment for heavy metals in the river, indicating a potential risk, might on people's health, especially after discharge point. Furthermore, a significant effect of carcinogenic risk by heavy metals of As and Hg was recognized in the same area. This study thus helps to understand clearly the alteration that happened in the water quality of Diyala-Sirwan river due to the discharge of untreated wastewater from Kalar city.

The Effect of the Effluent from a Small-Scale Conventional Wastewater Treatment Plant Treating Municipal Wastewater on the Composition and Abundance of the Microbial Community, Antibiotic Resistome, and Pathogens in the Sediment and Water of a Receiving Stream

The effluents of wastewater treatment plants (WWTPs) are major contributors of nutrients, microbes—including those carrying antibiotic resistance genes (ARGs)—and pathogens to receiving waterbodies. The effect of the effluent of a small-scale activated sludge WWTP treating municipal wastewater on the composition and abundance of the microbial community as well as the antibiotic resistome and pathogens in the sediment and water of the receiving stream and river was studied using metagenome sequencing and a quantitative approach. Elevated Bacteroidetes proportions in the prokaryotic community, heightened sulfonamide and aminoglycoside resistance determinants proportions, and an increase of up to three orders of magnitude of sul1–sul2–aadA–blaOXA2 gene cluster abundances were recorded in stream water and sediments 0.3 km downstream of a WWTP discharge point. Further downstream, a gradual recovery of affected microbial communities along a distance gradient from WWTP was recorded, culminating in the mostly comparable state of river water and sediment parameters 3.7 km downstream of WWTP and stream water and sediments upstream of the WWTP discharge point. Archaea, especially Methanosarcina, Methanothrix, and Methanoregula, formed a substantial proportion of the microbial community of WWTP effluent as well as receiving stream water and sediment, and were linked to the spread of ARGs. Opportunistic environmental-origin pathogens were predominant in WWTP effluent and receiving stream bacterial communities, with Citrobacter freundii proportion being especially elevated in the close vicinity downstream of the WWTP discharge point.

Analysis of Discharge Channel Characteristics Based on Three-Phase Flow Dielectric Characteristics in USV-MF Assisted WEDM-LS

In this paper, considering the effects of the characteristics of the three-phase flow dielectric in the discharge gap flow field on the discharge channels in the ultrasonic vibration and magnetic field assisted low speed WEDM, the model of discharge channel including discharge position and size of discharge channel is established and analyzed. Firstly, given working conditions of cutting workpiece with large thickness, a mechanism of bubble-particle bridging breakdown was proposed. Then a prediction model of the discharge point position in USV-MF assisted WEDM-LS under three-phase flow dielectric characteristics based on the breakdown mechanism was performed, and FEM software COMSOL was used to simulate and analyze this model. By comparing with the experimental results of discharge point position captured by high speed camera, the accuracy of the prediction results of discharge point position in USV-MF assisted WEDM-LS was verified, showing that this model can more accurately explain the dielectric breakdown in cutting workpiece with large thickness. Next, the model of radius of discharge channel including magnetic field intensity, electric field intensity, medium pressure and surface tension of discharge channel was established, and the influence of ultrasound and magnetic field on the size of discharge channel was analyzed theoretically. The radius of discharge channel in USV-MF assisted WEDM-LS was obtained by solving the partial differential equation in MATLAB. According to discharge point position and radius of the plasma discharge channel, surface morphology of workpiece was simulated by COMSOL. Finally, the experiment of photographing the discharge channel in USV-MF assisted WEDM-LS was carried out to verify the above model. It shows that the trend of the simulated results of discharge channel position is the same as that of the experimental results, and the error between the peak height value of the simulated surface morphology of workpiece and that of the experimental surface morphology of workpiece is within 6%.

Hydrogeological Changes along a Fault Zone Caused by Earthquakes in the Moncayo Massif (Iberian Chain, Spain)

The response of springs to earthquakes in the zone of moderate seismicity associated with the fault under study (the Talamantes–Castilruiz fault, Soria, Spain) always leads to a flow decrease regardless of the magnitude of the earthquake and the distance from the epicenter. The sensitivity of the springs is explained by the different degrees of the confinement of their aquifers. The semi-confined aquifer of the Vozmediano spring (1100 L/s) experiences short post-seismic events with a variable decrease in flow and an increase in turbidity, depending on the intensity of the earthquakes felt at the site (Intensity). These changes are likely due to elastic deformation and an increased permeability in their aquifers. This spring is an example of how previous (historical) earthquakes can break the aquifer through the fault causing horizontal movements of the groundwater and displacing the discharge point to a different fracture site located six kilometers from the initial point.

Markers Specific to Bacteroides fragilis Group Bacteria as Indicators of Anthropogenic Pollution of Surface Waters

The aim of this study was to evaluate the applicability of markers specific to Bacteroides fragilis group (BFG) bacteria as indicators of anthropogenic pollution of surface waters. In addition, the impact of wastewater treatment plants (WWTPs) on the spread of genes specific to fecal indicator bacteria and genes encoding antimicrobial resistance in water bodies was also determined. Samples of hospital wastewater (HWW), untreated wastewater (UWW), and treated wastewater (TWW) evacuated from a WWTP were collected, and samples of river water were taken upstream (URW) and downstream (DRW) from the wastewater discharge point to determine, by qPCR, the presence of genes specific to BFG, Escherichia coli and Enterococcus faecalis, and the abundance of 11 antibiotic resistance genes (ARGs) and two integrase genes. The total number of bacterial cells (TCN) in the examined samples was determined by fluorescence in situ hybridization (FISH). Genes specific to BFG predominated among the analyzed indicator microorganisms in HWW, and their copy numbers were similar to those of genes specific to E. coli and E. faecalis in the remaining samples. The abundance of genes specific to BFG was highly correlated with the abundance of genes characteristic of E. coli and E. faecalis, all analyzed ARGs and intI genes. The results of this study indicate that genes specific to BFG can be used in analyses of human fecal pollution, and as indicators of environmental contamination with ARGs. A significant increase in the copy numbers of genes specific to BFG, E. coli, and seven out of the 11 analyzed ARGs was noted in samples of river water collected downstream from the wastewater discharge point, which suggests that WWTPs are an important source of these genes in riparian environments.

The role of turbulence and internal waves in the structure and evolution of a near-field river plume

An along-channel momentum budget is quantified in the near-field plume region of a controlled river flow entering Doubtful Sound, New Zealand. Observations include highly resolved density, velocity and turbulence, enabling a momentum budget to be constructed over a control volume. Estimates of internal stress (τ) were made from direct measurements of turbulence dissipation rates (ϵ) using vertical microstructure profiles. High flow speeds of the surface plume over 2 m s−1 and strong stratification (N2∼10-1 s−2) resulted in enhanced turbulence dissipation rates (ϵ>10-3 W kg−1) and internal stress (τ>10-2 m2 s−2) at the base of the surface layer. Internal waves were observed propagating along the base of the plume, potentially released subsequent to a hydraulic jump in the initial 1 km downstream of the plume discharge point. The momentum flux divergence of these internal waves suggests that almost 15 % of the total plume momentum can be transported out of the system by wave radiation, therefore playing a crucial role in the redistribution of momentum within the near-field plume. Observations illustrate that the evolution of the momentum budget components vary between the distinct surface plume layer and the turbulent, shear-stratified interfacial layer. Within the surface plume, a momentum balance was achieved. The dynamical balance demonstrates that the deceleration of the plume, driven by along-channel advection, is controlled by turbulence stress from the plume discharge point to as far as 3 km downstream. In the interfacial layer, however, the momentum equation was dominated by the turbulence stress term and the balance was not closed. The redistribution of momentum within the shear-stratified layer by internal wave radiation and other hydraulic features could account for the discrepancy in the budget.