Behaviors of Homologous Antibiotic Resistance Genes in a Cephalosporin WWTP, Subsequent WWTP and the Receiving River

High concentrations of antibiotics in antibiotic production wastewater can cause the widespread transmission of antibiotic resistance genes (ARGs). Here, we collected a set of time series samples from a cephalosporin production wastewater treatment plant (X-WWTP), the subsequent municipal WWTP (Y-WWTP) and the receiving stream. Using a functional gene microarray, GeoChip 5.0, which contains multiple homologous probes for 18 ARG and 13 antibiotic metabolism gene (AMG) families, we found that more than 50% of homologous probes for 20 gene families showed a relative abundance higher in X-WWTP, while only 10–20% showed lower relative abundance. The different response patterns of homologous ARG (hARGs) within the same ARG family imply environmental selection pressures are only responsible for the ARG enrichment and spread of some specific instead of all ARG-containing microorganisms, which contradicted the traditionally held belief that environmental selection pressures, especially antibiotic concentration, select for all ARG-containing microorganisms thereby selecting different hARGs in the same ARG family in an undifferentiated way. Network results imply that hARGs from three β_lactamase families enriched under the selection pressure of high cephalosporin antibiotic concentrations in X-WWTP formed positively correlated homologous ARG clusters (pohARGCs). The pohARGCs were also enhanced in the sediment of the receiving stream. The enrichment of hARGs from three β_lactamase families was likely through microorganisms belonging to the Betaproteobacteria genus.

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.

Debris flow events in Austria - regional strategies for mitigation and adaptation in the light of climate change

<p>Recent years have repeatedly witnessed natural disasters throughout Austria, e.g. the catastrophic debris flows of 2012, 2013, 2016, 2017 and 2019 which caused enormous damage and losses in some areas. The impacts of climate change on these events is rather unclear in many cases, it must be assumed that the intensity and frequency of extreme events and natural hazards is likely to increase in future.</p><p>Management of bedload/debris flow processes to ensure the protective function is a major challenge. Observing the historical development shows the constant change of design types and constructions in the course of time. Hand in hand with technical progress, lessons learned from events in the light of climate change as well as a higher process understanding the constructions were constantly improved. Other reasons for the development of fitted systems with an integrative catchment-view down to the receiving stream are the high and still rising maintenance and clearance costs. On the basis of these findings and results, recommendations were derived to improve the function fulfilment of the technical protection measures. Furthermore, integrative concepts focus on the adaptation of the alpine forests to climate change. Under the principle, “fit for the future” the recommendations are summarized and presented in this contribution.</p>

Influence of Solar Energy on the Physicochemical Parameters of Effluent Sludge and the Receiving Stream of an Oxidation Pond

Aim: This study was aimed at determining the physicochemical characteristics (such as pH, dissolved oxygen, biological oxygen demand, nitrogen, phosphorus, chloride, iron, lead, magnesium etc.) of the effluent sludge from a sewage oxidation pond and the receiving stream before and after exposure to solar energy. This is to gain a better understanding on how ultraviolet radiations from sunlight alters the physicochemical parameters inherent in the sludge and the stream. Methods and Results: Effluent sludge samples and water samples from the receiving stream were collected and exposed to solar energy over a twenty-day period. Physicochemical parameters were measured using standard methods. Results revealed that mean values of dissolved oxygen and pH increased whereas those of biological oxygen demand, ammonia nitrogen, chloride, phosphorus, iron, lead zinc and magnesium reduced over the period study. Conclusion: The findings from this study suggest that the addition of solar energy to the chains of processes in sewage treatment will produce effluents with minimal content of nutrients from organic matter and heavy metals and these will ultimately protect the receiving stream from contamination, thus contributing to human health protection.

Compliance Monitoring of Microbiological and Physicochemical Parameters of Abattoirs’ Effluents Discharged into Water Bodies in Owerri, Nigeria

Aims: To assess the quality of abattoir effluents discharged into water bodies in Owerri Municipal, Nigeria using microbiological and physicochemical approaches. Study Design: The study employed microbiological and physicochemical parameters to determine effluent and water quality. Place and Duration of Study: Abattoirs in Owerri, Imo State, Nigeria, between September 2014 and February 2016. Methodology: Physicochemical and microbiological analyses were carried out on three abattoir effluents and their receiving water bodies. Counts of total heterotrophic bacteria, total coliform and faecal coliform, Vibrio, Salmonella and Shigella were carried using the plate count method. Results: The bacterial isolates in the various samples included members of the genera Bacillus, Citrobacter, Enterobacter, Escherichia, Klebsiella, Lactobacillus, Listeria, Micrococcus, Proteus, Salmonella, Serratia, Staphylococcus, Streptococcus and Vibrio. The order of increasing effluent’s total coliform and faecal counts within the different abattoirs are given as Egbu abattoir > Amakohia Ikeduru abattoir > Ahiara abattoir. For the receiving streams, the order was as follows, for the total coliform count: Egbu abattoir > Ahiara abattoir > Amakohia Ikeduru abattoir while for faecal coliform: Egbu abattoir > Amakohia Ikeduru abattoir > Ahiara abattoir. About 85.7% and 42.9% of the total bacterial isolates were found in the Egbu abattoir effluent and receiving the stream, respectively. Ahiara abattoir’s effluent had 66.7% of the bacteria while its receiving stream had 23.8%. Over 57% of the total bacterial isolates were distributed in the Amakohia Ikeduru abattoir with 33.3% for its receiving stream. Conclusion: This study revealed that pathogenic bacteria from abattoir were constantly discharged into receiving streams, thereby presenting serious health risks. The health status of residents of Owerri who have access to these water bodies should be studied to determine the health implications of such unregulated practices.

Phytoplankton diversity in Digboi oil refinery effluent receiving stream of Assam, India

A comprehensive study was carried out to investigate phytoplankton community and water quality in the Digboi oil refinery effluent stream. Taxonomic composition, abundance, spatial distribution, temporal dynamics of phytoplankton were studied along with physicochemical properties of water based on monthly data collected from seven selected sampling stations during April, 2011 - March, 2012. Altogether 139 species (7 orders, 19 families, 67 genera) of phytoplankton were identified of which Bacillariophyceae was the dominant class with 45 species followed by Chlorophyceae 40, Cyanophyceae 34 and Euglenophyceae 20. Though distinct changes in community structure were reported, higher phytoplankton abundance revealed during the post monsoon months. Correlation analysis showed influence of phenol and total oil content (TOC) along with pH, inorganic phosphorus and nitrate content in distribution and abundance of the phytoplankton.

Design a Vegetative Filter Strips Length Using VFSMOD_W Model for Reducing Sediments and Pesticides

The vegetative filter strips (VFS) are a useful tool used for reducing the movement of sediment and pesticide in therivers. The filter strip’s soil can help in reducing the runoff volume by infiltration. However, the characteristics of VFS (i.e., length) are not recently identified depending on the estimation of VFS modeling performance. The aim of this research is to study these characteristics and determine acorrelation between filter strip length and percent reduction (trapping efficiency) for sediment, water, and pesticide. Two proposed pesticides(one has organic carbon sorption coefficient, Koc, of 147 L/kg which is more moveable than XXXX, and another one has a Koc of 2070 L/kg which is less moveable than XXXX) are presented, where the goal is to prevent 95% of incoming sediment and 85% of the incoming pesticide to reach a receiving stream in still water, Oklahoma from a cultivated field (1250 m²),for 2 hour storm with 5 years return period. Several VFS lengths were simulated including1, 3, 5, 6, 9, 11, 12, and 13 m. The results showed that the percent of reduction of sediment, pesticide, and water mainly depends on VFS lengths. Moreover, considering the design storms range, the simulation illustrated that the optimal filter length was13m for silty clay loam. When the value of was increased from 147 L/kg to 6070 L/kg, the filter length decreased from 13 to 9.5 because of the increase in trapping efficiency. In addition, the results revealed that the trap­ping efficiency was for sediment but not for water orpesticide which was highly impacted by the narrow filter strips. The amount of the rainfall and runoff of the designated field was larger than the infiltration capacity of filter strips, which resulted in low trapping efficiency for pesticide and water. Keywords: Models ,runoff, sediment, vegetative filter strip, , water quality, watershed planning.