Quantification of filamentous bacteria in activated sludge systems can be made by manual counting under a microscope or by the application of various automated image analysis procedures. The latter has been significantly developed in the last two decades. In this work a new method based upon automated image analysis techniques was elaborated and presented. It consisted of three stages: (a) ...
Over the past ten years the management of microbiological drinking water quality in The Netherlands has shifted from curative administration toward a more preventative strategy. This shift in policy came as a result of the findings of reports from other developed countries which highlighted the risk from persistent pathogens such as Cryptosporidium, Giardia, some enteroviruses; and the pathogenic ...
ABSTRACTThe California Regional Water Quality Control Board, Santa Ana Region (RWQCB) required wastewater collection agencies in Orange County to report discharges from “pipe breaks, leaking sewer pipes and joints, and other subsurface discharges of wastewater.” The Orange County Sanitation District (OCSD), in conjunction with a research team from University of California, Irvine (UCI), developed ...
Untitled Document ABSTRACT Monitoring of recreational beaches for fecal indicator bacteria is currently performed using culturebased technology that can ...
The purpose of this study was to use molecular techniques to quantify and characterize ammonia-oxidizing bacteria (AOB) communities in several Intermittent Cycle Extended Aeration Systems (ICEAS®), and examine whether there are relationships between AOB community structure and system operational parameters and performance. Total AOBconcentrations measured at four plants ranged from 1.6×109 - ...
The objective of this study was to investigate the autoaggregation, coaggregation and biofilm formation of four bacteria namely Sphingobium, Xenophilus, Methylobacterium and Rhodococcus isolated from drinking water. Auto and coaggregation studies were performed by both qualitative (DAPI staining) and semi-quantitative (visual coaggregation) ...
Urbanization and frequent storms play important roles in increasing faecal bacteria pollution, especially for tropical urban catchments. However, only little information on the faecal bacteria levels from different land use types and the factors that influence bacteria concentrations is available. Thus, the objectives of this study were to quantify the levels and transport mechanism of faecal ...
Keywords: Engineered Channels, Bacteria, TMDL, Los Angeles River Problem Statement and Objectives: Many rivers in the US are channelized to control stormwater runoff and reduce the impacts of major flood events in the region. The characteristics of channelized rivers may vary from a completely concrete-box or trapezoidal channel to those with “soft-bottom” streambeds. ...
The purpose of this study was to identify triclosan tolerant heterotrophic plate count (HPC) bacteria from sewage effluent and to determine cross-resistance to antibiotics. R2 agar supplemented with triclosan was utilised to isolate triclosan resistant bacteria and 16S rRNA gene sequencing was conducted to identify the isolates. Minimum inhibitory concentrations (MICs) of organisms were ...
Urban drainage structures have increasing demands which can lead to increasing hydrogen sulphide related problems forming in places where they have not previously been prevalent. This puts pressure on the methods currently used to monitor and diagnose these problems and more sophisticated methods may be needed for identifying the origin of the problems. Molecular microbiological techniques, ...
Routine stormwater monitoring programs focus on quantification of average fecal indicator bacteria (FIB) concentration at the terminal watershed discharge point. While important for permit compliance, such monitoring provides little insight into relative bacteria levels from different land use types or the mechanisms that influence FIB concentrations. The goal of this study was to quantify the ...
An improved real-time PCR was developed to quantify Ammonia-Oxidising Bacteria (AOB) in aerobic granular sludge and activated sludge influenced by Pentachlorophenol (PCP), which ranged from 0 mg/L to 50 mg/L. With the increase of PCP concentration, there is no obvious variation of AOB quantification (p > 0.05) and COD removal rate in both types of sludge. However, the ammonia nitrogen removal of ...
Ammonia-oxidizing bacteria (AOB) are very sensitive to environmental conditions and wastewater treatment plant operational parameters. One of the most important factors affecting their activity is pH. Its effect is associated with: NH3/NH4+ and HNO2/NO2− chemical equilibriums and biological reaction rates. The aim of this study ...
The aim of the work was to quantify the influence of the simultaneous presence of flocs and granules in the nitrifying activity in a sequencing batch airlift reactor (SBAR). The nitrification rate and oxygen limitation of flocs, granules and hybrid sludge was investigated using respirometric assays at different dissolved oxygen concentrations. The spatial distribution of Ammonium Oxidizing ...
A 4-month sampling campaign has been conducted for the monitoring of three drinking water treatment plants using flow cytometry and culture-based methods to provide information related to changes in bacterial concentration according to treatments. Flow cytometry is a fast and user-friendly technique enabling bacteria quantification and viability assessment in less than 1 hour. Specific profiles ...
The present study aimed to compare several methods for quantifying and discriminating between the different physiological states of a bacterial population present in drinking water. Flow cytometry (FCM), solid-phase cytometry (SPC), epifluorescence microscopy (MSP) and culture method performances were assessed by comparing the results obtained for different water samples. These samples, ...
The Kinetico K5 drinking water station with Purefecta cartridge clearly passed the test when examined by the Bactiquant®-water method (US-EPA, verified technology) developed by Mycometer. The method is based on a highly sensitive fluorescence technology which is used to detect and quantify an enzyme activity in bacteria. The fluorescence produced is directly proportional to the content of ...
This study investigates the influence of gamma radiation on the total phenols, tannins and antimicrobial activity of ethanolic plant extracts of the bark and leaves of Anadenanthera colubrina (Vell.) Brenan (angico). The extracts were separated into four groups (0, 5, 7.5 and 10 kGy) to quantify total phenols (Folin-Ciocalteu method), tannins (precipitation of casein), and antimicrobial activity ...
Chem-bioflocculation (CBF) process was a new municipal wastewater treatment process developed in recent years. The flocculant dosage was one of the most important factors in operation optimization of chem-bioflocculation(CBF) treatment process. Five levels of flocculant dosage (PAFC) from 30mg/L to 100mg/L were applied to compare operational performance between CBF process and chemically enhanced ...
Acanthamoeba, human pathogens and natural hosts of pathogenic bacteria, may be accurately detected and quantified by real-time PCR if Acanthamoeba DNA are properly extracted and PCR inhibitors are effectively eliminated. However, the optimization of DNA extraction methods has not been reported for Acanthamoeba. This study compared the effectiveness of two DNA extraction/purification methods ...