Inlet Samples Research Articles

From the highway to receiving water bodies: identification and simultaneous quantification of small microplastics (< 100µm) in highway stormwater runoff.

Highway stormwater (HSW) runoff is among the environment's most important sources of microplastics. This study aimed to characterize via vibrational spectroscopy and quantify SMPs (small microplastics < 100µm) in HSW runoff from a trafficked highway entering a facility equipped with a filtration system and in those flowing out to the receiving water body near agricultural activities. Samples of the inlet runoff (from the highway) and outlet runoff (the discharge into the environment) were collected in different periods to investigate potential seasonal and spatial differences. The sampling, methodology, and analysis were thoroughly carried out to quantify and simultaneously identify SMPs via Micro-FTIR to obtain a specific novel dataset to assess the environmental quality of highway pollution. A significant difference between inlet and outlet samples was reported; the highest abundance in inlet samples was 39813 ± 277 SMPs L.1 (SW10 IN; average length of 77µm), while the highest one in outlet samples was 15173 ± 171 SMPs L-1 (SW10 OUT; SMPs' average length of 63µm). Polyamide 6 (PA 6) and High-Density Polyethylene (HDPE) were predominant. Our results show that these HSW treatment plants, designed for managing regulated pollutants, can intercept SMPs, improving the quality of HSW runoff discharged into the environment.

Water Quality Characteristics and Water-Rock Interaction Mechanisms of Coal Mine Underground Reservoirs.

Constructing underground reservoirs in coal mines can effectively improve the recycling of mine water. Water-rock interactions within underground reservoirs have been demonstrated to improve water quality; however, the mechanisms underlying these water-rock interactions remain unclear, hindering the widespread applications of underground reservoirs. Thus, this study focused on the underground reservoir of the Shendong Daliuta coal mine. Through on-site sampling tests and single-mineral leaching experiments, combined with X-ray diffraction, X-ray fluorescence spectrometry, and scanning electron microscopy, the water quality characteristics of the inlet and outlet water samples from the coal mine underground reservoir were analyzed. Moreover, the physical and chemical properties of the collapsed rocks in the reservoir were investigated, with the aim of clarifying the mechanism underlying the water-rock interactions in coal mine underground reservoirs. The results revealed a significant self-purification effect of the coal mine underground reservoir. Compared with the inlet water sample, the outlet water sample featured substantially reduced amounts of solid-suspended substances, turbidity, total dissolved solids, and electrical conductivity, with the average removal rates of Fe and Mn approaching 98.73 and 92.12%, respectively. Along the flow direction of the inlet and outlet water of the coal mine underground reservoir, the concentrations of Na+ and Cl- presented an increasing trend, whereas the concentrations of Ca2+, Mg2+, and HCO3 - presented a decreasing trend. The concentration of K+ changed insignificantly, while the concentration of SO4 2- fluctuated unstably. The collapsed rocks in the Daliuta coal mine underground reservoir primarily comprised mudstone and sandstone with mineral components including quartz, orthoclase, albite, illite, kaolinite, glauconite, calcite, and pyrite. Among these, kaolinite exhibited the strongest adsorption capacity for Na+, Ca2+, and Mg2+ present in the mine water, while glauconite demonstrated the strongest dissolution capacity for Mg2+. Illite presented the strongest dissolution capacity for K+, while albite presented the strongest dissolution capacity for Na+. The water-rock interactions within the coal mine underground reservoir primarily included dissolution and adsorption processes, wherein mudstone and fine sandstone both played dominant roles in the adsorption of Ca2+, as well as in the dissolution of K+, Na+, and Mg2+. In particular, mudstone exhibited a stronger adsorption capacity than fine sandstone, whereas fine sandstone presented a stronger dissolution capacity than mudstone. Thus, our results offer theoretical guidance for understanding water quality purification mechanisms in coal mine underground reservoirs.

Metagenomic analysis reveals differential effects of sewage treatment on the microbiome and antibiotic resistome in Bengaluru, India

ABSTRACT Climate change and health are closely linked to urban wastewater used for irrigation. Sewage treatment plants (STPs) provide ideal environments and niche availability for the transmission of antibiotic resistance genes (ARGs) among pathogenic and non-pathogenic bacteria. In this study, we examined the differential effect of sewage processing methods from the inlet to the outlet on the microbial diversity and antibiotic resistomes of 26 STPs in the urban sewage network of Bengaluru, India. We screened 478 ARGs and found 273 in wastewater, including clinically relevant genes such as CTX-M, qnr, sul-1, and NDM-1, which confer resistance to six major classes of antibiotics. The richness of ARGs was higher in sewage inlets compared with outlets. We observed a downward shift in drug classes from inlet to outlet samples, except for aminoglycosides, beta-lactams, MLSB, and tetracycline. Inlet samples exhibited more complex correlations between ARGs and bacteria compared with outlet samples. Our findings serve as a baseline study that could aid in the quantification of genes from both culturable and non-culturable taxa and will assist in the development of policies and strategies to address water quality issues associated with the use of recycled water.

Nutrient Removal Efficiencies in a Bioretention Cell Using Pre-Treated Coconut By-Product as Carbon Source

Abstract In this research, the appropriateness of alkali pre-treatment on coconut by-products was managed by exposing coconut husk and shell to 2M NaOH. The powdered samples were analysed for morphology observation, Fourier Transform Infrared (FTIR), Particle Size Analyzer (PSA), and water quality tests. Weakening the hemicellulose structure resulted from subjecting the coconut shell to alkali pre-treatment shown in the morphology observation. Furthermore, the FTIR analysis exhibited the presence of O-H stretch in all pre-treated samples representing an indication for occurring the lignin breakdown, while an absence of the C=O functional group was shown in both additive samples after their subjection to alkali pre-treatment. In PSA analysis, the particles of all samples were found finer than the particle size distribution standards, in which the smallest D50 was obtained for the treated coconut shell (TCS), followed by untreated coconut shell (UCS), untreated coconut husk (UCH), and treated coconut husk (TCH). Among all the powdered samples (TCS, UCS, UCH, and TCH) analysed in this study, only TCH values met the ranges provided and recommended by the Urban Stormwater Management Manual for Malaysia (MSMA) and the Australian Department of Sustainability, Environment, Water, Population, and Communities (DSEWPC). Meanwhile, a poor removal rate for total suspended solids (TSS) was attained due to the contribution of TSS by the filter media which caused the TSS rates to surpass the inlet values. Additionally, the presence of a high concentration of total phosphorous (TP) in all the tested samples indicated their capabilities to provide PO43 in the bioretention cell, which is a vital nutrient for the plant’s growth. In contrast, Ammoniacal Nitrogen (AN) with a concentration rate as low as 4 mg/L was observed throughout the test periods which showed a significant reduction compared to the rate of AN at the inlet samples ranged between 5.2 and 11.4 mg/L. The findings indicated that coconut by-products, when subjected to an alkali pre-treatment process, are appropriate for incorporation as additives in bioretention filter media.

Urban stormwater green infrastructure: Evaluating the public health service role of bioretention using microbial source tracking and bacterial community analyses

Bioretention cells (BRCs) control stormwater flow on-site during precipitation, reducing runoff and improving water quality through chemical, physical, and biological processes. While BRCs are effective in these aspects, they provide habitats for wildlife and may face microbial hazards from fecal shedding, posing a potential threat to human health and the nearby environment. However, limited knowledge exists regarding the ability to control microbial hazards (e.g., beyond using typical indicator bacteria) through stormwater biofiltration. Therefore, the purpose of this study is to characterize changes in the bacterial community of urban stormwater undergoing bioretention treatment, with the goal of assessing the public health implications of these green infrastructure solutions. Samples from BRC inflow and outflow in Columbus, Ohio, were collected post-heavy storms from October 2021 to March 2022. Conventional culture-based E. coli monitoring and microbial source tracking (MST) were conducted to identify major fecal contamination extent and its sources (i.e., human, canine, avian, and ruminant). Droplet digital polymerase chain reaction (ddPCR) was utilized to quantify the level of host-associated fecal contamination in addition to three antibiotic resistant genes (ARGs): tetracycline resistance gene (tetQ), sulfonamide resistance gene (sul1), and Klebsiella pneumoniae carbapenemase resistance gene (blaKPC). Subsequently, 16S rRNA gene sequencing was conducted to characterize bacterial community differences between stormwater BRC inflow and outflow. Untreated urban stormwater reflects anthropogenic contamination, suggesting it as a potential source of contamination to waterbodies and urban environments. When comparing inlet and outlet BRC samples, urban stormwater treated via biofiltration did not increase microbial hazards, and changes in bacterial taxa and alpha diversity were negligible. Beta diversity results reveal a significant shift in bacterial community structure, while simultaneously enhancing the water quality (i.e., reduction of metals, total suspended solids, total nitrogen) of urban stormwater. Significant correlations were found between the bacterial community diversity of urban stormwater with fecal contamination (e.g. dog) and ARG (sul1), rainfall intensity, and water quality (hardness, total phosphorous). The study concludes that bioretention technology can sustainably maintain urban microbial water quality without posing additional public health risks, making it a viable green infrastructure solution for heavy rainfall events exacerbated by climate change.

A Battery of Simple Bioassays for Domestic and Industrial Wastewater Treatment Plants in Konya, Turkey

Wastewater ingredients present risks to the environment and can cause health problems. The aim of this study was to identify the toxicological effects of influent and effluent wastewater from Konya Urban Wastewater Treatment Plant (KU WWTP) and Konya Organized Industrial Zone Wastewater Treatment Plant (KOI WWTP). Three different trophic level toxicity tests were conducted to determine the possible harmful effects of wastewater on the environment. The base toxic unit values of the Lepidium sativum toxicity test for the inlet and outlet samples of KU WWTP were found to be 1.43 and 1.10, respectively. Both values classified the analyzed wastewater into the “toxic” category. Wastewater entering the KU wastewater treatment facility was classified as “toxic” for the presence of toxic substances according to the Vibrio fischeri toxicity testing. Influent samples from the KOI wastewater treatment plant were classified as “toxic” with the Vibrio fischeri toxicity test. In addition, based on the fish bioassay value (TDF), wastewater from the KOI treatment facility was also classified as “toxic”. It was concluded that increased chemical oxygen demand and concentrations of total nitrogen and phosphorus and of certain heavy metals above the limits played a decisive role in classifying the samples as “toxic”. The results of this study suggest that all three tests have the potential to assess wastewater toxicity and that changes in wastewater properties may result in differences in test sensitivity.

Non-target analysis for water characterization: wastewater treatment impact and selection of relevant features.

Non-target analyses were conducted to characterize and compare the molecular profiles (UHPLC-HRMS fingerprint) of water samples from a wastewater treatment plant (WWTP). Inlet and outlet samples were collected from three campaigns spaced 6months apart in order to highlight common trends. A significant impact of the treatment on the sample fingerprints was shown, with a 65-70% abatement of the number of features detected in the effluent, and more polar, smaller and less intense molecules found overall compared to those in WWTP influent waters. Multivariate analysis (PCA) associated with variations of the features between inlets and outlets showed that features appearing or increasing were correlated with effluents while those disappearing or decreasing were correlated with influents. Finally, effluent features considered as relevant to a potentially adverse effect on aqueous media (i.e. those which appeared or increased or slightly varied from the influent) were highlighted. Three hundred seventy-five features common with the 3 campaigns were thus selected and further characterized. For most of them, elementary composition was found to be C, H, N, O (42%) and C, H, N, O, P (18%). Considering the MS2 spectra and several reference MS2 databases, annotations were proposed for 35 of these relevant features. They include synthetic products, pharmaceuticals and metabolites.

Normothermic Ex Vivo Liver Machine Perfusion in Mouse.

This protocol presents an optimized erythrocytes-free NEVLP system using mouse livers. Ex vivo preservation of mouse livers was achieved by employing modified cannulas and techniques adapted from conventional commercial ex vivo perfusion equipment. The system was utilized to evaluate the preservation outcomes following 12 h of perfusion. C57BL/6J mice served as liver donors, and the livers were explanted by cannulating the portal vein (PV) and bile duct (BD), and subsequently flushing the organ with warm (37 °C) heparinized saline. Then, the explanted livers were transferred to the perfusion chamber and subjected to normothermic oxygenated machine perfusion (NEVLP). Inlet and outlet perfusate samples were collected at 3 h intervals for perfusate analysis. Upon completion of the perfusion, liver samples were obtained for histological analysis, with morphological integrity assessed using modified Suzuki-Score through Hematoxylin-Eosin (HE) staining. The optimization experiments yielded the following findings: (1) mice weighing over 30 g were deemed more suitable for the experiment due to the larger size of their bile duct (BD). (2) a 2 Fr (outer diameter = 0.66 mm) polyurethane cannula was better suited for cannulating the portal vein (PV) when compared to a polypropylene cannula. This was attributed to the polyurethane material's enhanced grip, resulting in reduced catheter slippage during the transfer from the body to the organ chamber. (3) for cannulation of the bile duct (BD), a 1 Fr (outer diameter = 0.33 mm) polyurethane cannula was found to be more effective compared to the polypropylene UT - 03 (outer diameter = 0.30 mm) cannula. With this optimized protocol, mouse livers were successfully preserved for a duration of 12 h without significant impact on the histological structure. Hematoxylin-Eosin (HE) staining revealed a well-preserved morphological architecture of the liver, characterized by predominantly viable hepatocytes with clearly visible nuclei and mild dilation of hepatic sinusoids.

PacBio next-generation sequencing uncovers Apicomplexa diversity in different habitats

The phylum Apicomplexa comprises a large group of intracellular protozoan parasites. These microorganisms are known to infect a variety of vertebrate and invertebrate hosts, leading to significant medical and veterinary conditions such as toxoplasmosis, cryptosporidiosis, theileriosis, and eimeriosis. Despite their importance, comprehensive data on their diversity and distribution, especially in riverine environments, remain scant. To bridge this knowledge gap, we utilized next-generation high-throughput 18S rRNA amplicon sequencing powered by PacBio technology to explore the diversity and composition of the Apicomplexa taxa. Principal component analysis (PCA) and principal coordinate analysis (PCoA) indicated the habitat heterogeneity for the physicochemical parameters and the Apicomplexa community. These results were supported by PERMANOVA (P < 0.001), ANOSIM (P < 0.001), Cluster analysis, and Venn diagram. Dominant genera of Apicomplexa in inlet samples included Gregarina (38.54%), Cryptosporidium (32.29%), and Leidyana (11.90%). In contrast, outlet samples were dominated by Babesia, Cryptosporidium, and Theileria. While surface water samples revealed 16% and 8.33% relative abundance of Toxoplasma and Cryptosporidium, respectively. To our knowledge, the next-generation high throughput sequencing covered a wide range of parasites in Egypt for the first time, which could be useful for legislation of the standards for drinking water and wastewater reuse.

Efisiensi Pengolahan Air Limbah Domestik pada IPAL Komunal Di Kabupaten Bone Bolango

Waste water needs to be managed properly based on its characteristics to reduce the levels of contaminants contained therein. Communal IPAL or Waste Water Treatment Plants (WWTP) is a centralized wastewater treatment system. Several Communal WWTPs in Bone Bolango Regency have been built, but monitoring is rarely carried out. The purpose of this research was to determine the processing efficiency of communal WWTPs in Kabila District (Dutohe Barat Village and Tanggilingo Village), and Tilongkabila District (Butu Village and Iloheluma Village). The parameters measured were Total Suspended Solid (TSS), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Coliform, Ammonia, and fatty oil tests from inlet and outlet water samples from WWTP. The values obtained are then compared with the quality standards based on the Indonesian National Standard (SNI) 6989.59:2008 concerning Water and Wastewater. The research method uses non-experimental with a quantitative descriptive approach. Sampling using a purposive sampling technique. Based on the results of observations, it was found that there were differences in the results of the efficiency of domestic wastewater treatment, namely the highest TSS removal efficiency in Butu Village (82.9); total coliform in all locations (0); the highest removal in efficiency values were in Iloheluma Village, namely BOD (100), Ammonia (86.95), COD (65.53) and fatty oil efficiency values (98.11) in Tanggilingo Village. The results of this research can be used as a reference for the Regional Government of Bone Bolango Regency to improve the Communal WWTP sustainably to overcome environmental pollution.

Emerging pollutants characterization, mitigation and toxicity assessment of sewage wastewater treatment plant- India: A case study

India faces major challenges related to fresh water supply and the reuse of treated wastewater is an important strategy to combat water scarcity. Wastewater in Gorakhpur, India, is treated by a decentralised wastewater treatment system (DEWATS) and the treated wastewater is reused in the rural area. This research provides important scientific data that ascertain the safety of wastewater reuse in this region. The physicochemical characteristics, including pigment, ionic strength, BOD, COD, TDS, TSS, salinity, total N, ammonium N, phenolics, heavy metals, and sulphate, of the inlet and outlet sewage water samples (SWWs) from a wastewater treatment facility was conducted. These parameters were found to be significantly over the national limit. The inlet and outlet samples were further characterised by using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR) and gas chromatography–mass spectrometry (GC–MS). SEM showed microstructure and the presence of various metals, polymers, and other co-pollutants in the samples and FT-IR confirmed the presence of aldehyde, hard liquor, and nitrogen molecules in the SWW's discharge. Many endocrine disruptors and potentially mutagenic chemical substances (e.g., Dodecane, Hexadecane, Octadecane etc.) were identified in the outlet SWW by the GC–MS analysis. Toxicity of the SWW was assessed via phytotoxicity assessment using Phaseolus mungo L. and histological and biochemical analyses of Heteropneustes fossilis in a 24-h exposure study. Results confirmed the wastewater was harmful and inhibited germination of P. mungo L. by >80% compared to the control, destroyed gill laminae and significantly increased oxidative stress (above 5% increase in catalase production) in H. fossilis. This work clearly demonstrated that the quality of the treated wastewater in Gorakhpur was poor and immediate action is needed before it can be discharged or reused.

Analysis of the Copper (Cu), Chromium (Cr), and Manganese (Mn) Levels from the Steel Industry Liquid Waste by Atomic Absorption Spectrophotometry Method

Liquid waste from the steel industry processing, washing machine, and kitchenware foundry that is disposed containing copper (Cu), chromium (Cr) and manganese (Mn) elements which is harmful to enviromental. The levels of elemental copper (Cu), chromium (Cr), and manganese (Mn) were analyzed using Atomic Absorption Spectrophotometry (AAS) method. The effluent samples were destructed with the addition of concentrated HNO3. Then determining of the concentration of the element copper (Cu), chromium (Cr) and manganese (Mn) using Atomic Absorption Spectrophotometer with a calibration curve. The obtained results for the levels of copper (Cu) on the inlet samples were 0.9714 mg/L - 0.9719 mg/L, the outlet samples were 3.9990 mg/L - 4.0002 mg/L. Hence, the levels of the element chromium (Cr) on inlet samples were 0.0295 mg/L - 0.0297 mg/L, the outlet samples were 0.0399 mg/L - 0.0400 mg/L and the levels of manganese (Mn) in the inlet samples were 0.1269 mg/L - 0.1271 mg/L in a outlet samples were 2.9699 mg/L - 2.9701 mg/L. Then the steel industry wastewater for elemental copper (Cu) and manganese (Mn) has exceeded the limits that have been instituted by the Minister of Environment Decree No. 51, 1995, about the Liquid Waste Quality Standard for Industrial Activity

Evaluation of the Implementation Integrated Biological System Industrial Wastewater Treatment Plant: Pollutant Removal, Operational Maintenance, Estimation of Carbon Emission

The development of WWTP in business activities needs to pay attention to getting appropriate WWTP that is more valuable to support sustainable development. This study aims to evaluate two systems of integrated biological WWTP; anaerobic-wetland, and anaerobic-aerobic-wetland, including the effectiveness of pollutant removal, operational and maintenance, and estimation of carbon emissions. The performance of pollutant removal was evaluated by analyzing inlet and outlet samples of WWTP. An operational and maintenance evaluation was carried out by studying the WWTP operating system and maintenance procedures supported by a literature review. Carbon emission estimation was carried out using a formula referring to the IPCC Guidelines (2006). Organic matter removal of anaerobic-aerobic-wetland WWTP in the form of BOD₅ and COD are 92.12% and 91.72%, respectively, higher than anaerobic-wetland WWTP are 88.69% of BOD₅ and 77.62% of COD. Anaerobic-aerobic-wetland WWTP needs more maintenance and operation than anaerobic-wetland WWTP. The highest carbon emission of both WWTP is 41530.91 kgCO₂ eq/year of anaerobic-wetland WWTP from the organic matter removal process and 46485.15 kgCO₂ eq/year of anaerobic-aerobic-wetland WWTP. Electrical energy consumption emits in anaerobic-aerobic-wetland WWTP is 22338 kgCO₂ eq/year higher than anaerobic-wetland WWTP at 4299.70 kgCO₂ eq/year. Total carbon emissions of anaerobic-wetland WWTP is 47404.58 kgCO₂ eq/year and anaerobic-aerobic-wetland WWTP is 68900.23 kgCO₂ eq/year.

Bacterial composition in Swedish raw drinking water reveals three major interacting ubiquitous metacommunities.

BackgroundSurface raw water used as a source for drinking water production is a critical resource, sensitive to contamination. We conducted a study on Swedish raw water sources, aiming to identify mutually co‐occurring metacommunities of bacteria, and environmental factors driving such patterns.MethodsThe water sources were different regarding nutrient composition, water quality, and climate characteristics, and displayed various degrees of anthropogenic impact. Water inlet samples were collected at six drinking water treatment plants over 3 years, totaling 230 samples. The bacterial communities of DNA sequenced samples (n = 175), obtained by 16S metabarcoding, were analyzed using a joint model for taxa abundance.ResultsTwo major groups of well‐defined metacommunities of microorganisms were identified, in addition to a third, less distinct, and taxonomically more diverse group. These three metacommunities showed various associations to the measured environmental data. Predictions for the well‐defined metacommunities revealed differing sets of favored metabolic pathways and life strategies. In one community, taxa with methanogenic metabolism were common, while a second community was dominated by taxa with carbohydrate and lipid‐focused metabolism.ConclusionThe identification of ubiquitous persistent co‐occurring bacterial metacommunities in freshwater habitats could potentially facilitate microbial source tracking analysis of contamination issues in freshwater sources.

Monitoring and assessment of Dracaena-based constructed vertical flow wetlands treating textile dye wastewater.

The monitoring and assessment of multiple constructed vertical flow wetlands (CVFWs) treating textile dye wastewater (metanil yellow as dye) are studied covering three seasons. Three CVFWs (CVFW-1, dye—5 mg/l; CVFW-2, dye—50 mg/l; and CVFW-3, dye—100 mg/l) and a control (dye—5 mg/l) were used. The CVFWs with Dracaena (an ornamental plant) efficiently removed contaminants like dye, COD, NH4+-N, and PO43−-P from the wastewater under varying inlet dye concentrations, indicating its dependence on meteorological conditions. Substantial dye removal was observed to be maximum in summer (control, 44.3%; CVFW-1, 75.1%; CVFW-2, 76.1%; CVFW-3, 46%), but lesser in winter (control, 45%; CVFW-1, 73.1%; CVFW-2, 76.8%; CVFW-3, 42.6%) and minimum in monsoon (control, 40.8%; CVFW-1, 63.5%; CVFW-2, 51.6%; CVFW-3, 37.1%), respectively. Efficiency was less in CVFW-3 as it observed plant stress due to higher inlet dye concentration. COD removal was higher in winter, followed by summer and monsoon. A first-order kinetic model was used to investigate the efficiency of the CVFW system w.r.t. contaminant removal. Various functional groups were characterized using Fourier transform infrared spectroscopy (FTIR) from the inlet and outlet water samples of different CVFWs. The Dracaena accumulated various elements and oxides during the treatment with no stress on its health. No effects on plant health highlight the suitability of Dracaena for textile wastewater treatment. The results were validated using statistical tools like the Mann–Whitney U test and principal component analysis (PCA).Supplementary InformationThe online version contains supplementary material available at 10.1007/s10661-022-10415-y.

Determination of Chemical Oxygen Demand (COD) Concentration in Domestic Wastewater Using UV-Vis Spectrophotometry Method Based On The Effect Of Reflux Time And Preservation Time

The purpose of determining Chemical Oxygen Demand (COD) in samples of domestic wastewater is to determine the effect of variations in the reflux process time which is set to 0, 30, 60, 90, and 120 minutes as well as with variations in the testing time which are set to 0, 3, and 7 days. Determination of LOD and LOQ using a UV-Vis Spectrophotometer was also carried out and the regression equation y = 0.0003x + 0.0066 with a coefficient of determination (R2) was 0.998 with LOD and LOQ values ​​respectively 40.0416 mg O2/L and 133.4721 mg O2/L. Determination of the effect of reflux time and preservation time on COD levels was carried out statistically, namely the normality test (Kolmogorov-Smirnov Test) and homogeneity test (Levene Test) ending with a two-way ANOVA test with a probability or significance value of the inlet and outlet samples of 0.000 &lt; 0.05 ( ). Reflux time affects COD levels, the longer the reflux time, the higher and more stable COD levels. Preservation time affects the decrease in COD levels, which is the longer the preservation time, the greater the decrease in COD levels.

Lab-on-printed circuit board based water harvesting condensation particle counter for ubiquitous monitoring of airborne ultrafine particles

We have developed a water harvesting condensation particle counter (WHCPC) using lab-on-printed circuit board (PCB) technology. Our method provides an inexpensive, compact, and highly accurate system for the ubiquitous monitoring of airborne ultrafine particles (UFPs). Lab-on-PCB-based WHCPC uses water as the working fluid to monitor harmless UFPs; it does not require water replenishment using a moderated water condensation method. Lab-on-PCB-based WHCPC consists of two main parts, a UFP growth section and a mini-OPC, through which UFPs are grown into micro-sized droplets and the grown droplets are single-counted. The UFP growth section consists of two PCBs and a 3D-printed channel. The heater, temperature sensor, and hydrophilic micropillar array wick, which are essential for the growth of UFPs, are integrated on the PCBs. Simulations were performed to verify the saturated-air generation and water collection in the UFP growth section. The dew points of the inlet and outlet air samples were measured to verify water collection using the moderated water condensation method. Through quantitative experiments using UFPs artificially generated in the laboratory, particles of 9.4 nm could be counted. It was possible to precisely measure the number concentration (2500–270000 N cm−3) over a wide range. In addition, the stability of the proposed system was confirmed through a long-term comparison with the reference CPC in an outdoor environment. The proposed system realized the sensorization of CPC because it could monitor harmless UFPs, with minimal maintenance; the proposed system is also inexpensive and compact.

Photocatalytic degradation of amoxicillin from aqueous solutions by titanium dioxide nanoparticles loaded on graphene oxide.

The photocatalytic degradation of amoxicillin (AMX) by titanium dioxide nanoparticles loaded on graphene oxide (GO/TiO2) was evaluated under UV light. Experimental results showed that key parameters such as initial pH, GO/TiO2 dosage, UV intensity, and initial AMX concentration had a significant effect on AMX degradation. Compared to the photolysis and adsorption processes, the AMX degradation efficiency was obtained to be more than 99% at conditions including pH of 6, the GO/TiO2 dosage of 0.4 g/L, the AMX concentration of 50 mg/L, and the intensity of 36 W. Trapping tests showed that all three hydroxyl radical (OH•), superoxide radical (O2•-), and hole (h+) were produced in the photocatalytic process; however, h+ plays a major role in AMX degradation. Under UV irradiation, GO/TiO2 showed excellent stability and recyclability for 4 consecutive reaction cycles. The analysis of total organic carbon (TOC) suggested that AMX could be well degraded into CO2 and H2O. The formation of NH4+, NO3-, and SO42- as a result of AMX degradation confirmed the good mineralization of AMX in the GO/TiO2/UV process. The toxicity of the inlet and outlet samples of the process has been investigated by cultivation of Escherichia coli and Streptococcus faecalis, and the results showed that the condition is suitable for the growth of organisms. The photocatalytic degradation mechanism was proposed based on trapping and comparative tests. Based on the results, the GO/TiO2/UV process can be considered as a promising technique for AMX degradation due to photocatalyst stability, high mineralization efficiency, and effluent low toxicity.

First surveillance of SARS-CoV-2 and organic tracers in community wastewater during post lockdown in Chennai, South India: Methods, occurrence and concurrence.

Surveillance of SARS-CoV-2 and organic tracers (OTs) were conducted in the community wastewater of Chennai city and the suburbs, South India, during partial and post lockdown phases (August–September 2020) as a response to the coronavirus disease 2019 (COVID-19) pandemic. Wastewater samples were collected from four sewage treatment plants (STPs), five sewage pumping stations (SPSs) and at different time intervals from a suburban hospital wastewater (HWW). Four different methods of wastewater concentrations viz., composite (COM), supernatant (SUP), sediment (SED), and syringe filtration (SYR) were subjected to quantitative real time-polymerase chain reaction (qRT-PCR). Unlike HWW, STP inlet, sludge and SPS samples were found with higher loading of SARS-CoV-2 by SED followed by SUP method. Given the higher levels of dissolved and suspended solids in STPs and SPSs over HWW, we suspect that this enveloped virus might exhibit the tendency of higher partitioning in solid phase. Cycle threshold (Ct) values were < 30 in 50% of the HWW samples indicating higher viral load from the COVID-19 infected patients. In the STP outlets, a strict decline of biochemical oxygen demand, >95% removal of caffeine, and absence of viral copies reflect the efficiency of the treatment plants in Chennai city. Among the detected OTs, a combination of maximum dynamic range and high concurrence percentage was observed for caffeine and N1 gene of SARS-CoV-2. Hence, we suggest that caffeine can be used as an indicator for the removal of SARS-CoV-2 by STPs. Our predicted estimated number of cases are in line with the available clinical data from the catchments. Densely distributed population of the Koyambedu catchment could be partly responsible for the high proportion of estimated infected individuals during the study period.

The presence of SARS-CoV-2 in raw and treated wastewater in 3 cities of Iran: Tehran, Qom and Anzali during coronavirus disease 2019 (COVID-19) outbreak.

This study aimed to identifying the presence of SARS-CoV-2 RNA in raw and treated wastewater during the COVID-19 outbreak in Tehran, Qom and Anzali cities (Iran). From three wastewater treatment plants (WWTPs), 28 treated and untreated wastewater composite samples were collected from April 4 to May 2, 2020. In this study, polyethylene glycol 6000 (PEG 6000) was used through one-step real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) for identification of RNA viruses. SARS-CoV-2 RNA was elicited from wastewater composite samples in all inlet samples taken from the three above mentioned cities. The results of outlet samples were as follows: 1) Results from Qom and East Anzali outlets showed no trace of SARS-CoV-2 RNA despite the difference in treatment disinfection method used (chlorine vs. ultraviolet (UV) disinfection). 2. In Tehran, SARS-CoV-2 RNA was not detected in any of the outlet samples taken from the modules disinfected by UV. Out of the four samples taken from the modules disinfected by chlorine, two were positive for the SARS-CoV-2 RNA which could have been caused by deficiencies in operation and maintenance. It can be concluded that meeting the standards of operation and maintenance (O&M) in WWTPs can considerably ensure that wastewater does not act as one of the roots of transmission for the disease.