Drainage Samples Research Articles

Bench-scale study of active mine water treatment using cement kiln dust (CKD) as a neutralization agent

The overall objective of this study was to investigate the potential impact on settled water quality of using cement kiln dust (CKD), a waste by-product, to replace quicklime in the active treatment of acidic mine water. Bench-scale experiments were conducted to evaluate the treatment performance of calcium hydroxide (Ca(OH) 2) slurries generated using four different CKD samples compared to a control treatment with quicklime (CaO) in terms of reducing acidity and metals concentrations in acid mine drainage (AMD) samples taken from the effluent of a lead/zinc mine in Atlantic Canada. Results of the study showed that all of the CKD samples evaluated were capable of achieving greater than 97% removal of total zinc and iron. The amount of solid alkaline material required to achieve pH targets required for neutralization of the AMD was found to be higher for treatment with the CKD slurries compared to the quicklime slurry control experiments, and varied linearly with the free lime content of the CKD. The results of this study also showed that a potential benefit of treating mine water with CKD could be reduced settled sludge volumes generated in the active treatment process, and further research into the characteristics of the sludge generated from the use of CKD-generated calcium hydroxide slurries is recommended.

Assessment of drainage water quality in pre- and post-irrigation seasons for supplemental irrigation use

Knowledge on hydrochemistry is very important to assess the quality of water for effective management of water resources or drainage water reuse. On this basis, an assessment of water quality was conducted in the Agoulinitsa district in Peloponnese (western Greece). Both drainage and irrigation channel water samples have been collected, treated, and subjected to chemical analysis. A characterization has been carried out using the Piper-trilinear diagram. Assessment of the water samples from the point of view of sodium adsorption ratio, Na(+)%, and residual sodium carbonate indicated that 60.0% and 83.3% of the drainage water samples during pre- and post-irrigation season, respectively, as well as the irrigation channel water samples, are chemically suitable for irrigation use. Moreover, assessment of the water samples by comparing quality parameters with the Food and Agriculture Organization guidelines indicated that 20.0% and 44.4% of the drainage water samples collected during pre- and post-irrigation season, respectively, as well as the irrigation channel water samples could cause slight to moderate problems to the plants. On the other hand, 80.0% and 55.6% of the drainage water samples collected during pre- and post-irrigation season, respectively, could cause immediate development of severe problems to the plants growth.

Changes in the composition of an acid mine drainage microbial community upon successive transfers in medium containing low-grade copper sulfide

A consortium of microorganisms from acid mine drainage samples was cultured in modified 9K medium containing low-grade copper sulfide. The culture was maintained for sixty days and then transferred to fresh medium. This process was repeated three more times and a final consortium exhibiting a copper extraction rate of 89.3% was obtained. RFLP and microarrays analysis of 16S rRNA sequences retrieved from the consortia showed that Acidithiobacilluscaldus, Leptospirillumferriphilum, Sulfobacillus sp., Acidiphilium sp., and Sulfolobus spp. were represented in higher numbers in the consortia obtained in the copper-containing medium than in the original consortium. In contrast, a decrease in Acidithiobacillus ferrooxidans, Alicyclobacillus sp., Pseudomonas sp., and Sulfobacillus thermosulfidooxidans was observed. The abundance of genes related to sulfur metabolism from At. caldus and Sulfolobus spp., iron oxidation from Leptospirillum sp. and metal resistance from most of the detected microorganisms increased as the consortium was successively transferred into fresh medium.

The effect of bevacizumab on wound healing after resection of colorectal liver metastases despite persistent VEGF inactivation at wound sites.

e14005 Background: The antibody bevacizumab (Bev) has proven a promising tool for anti-angiogenic cancer therapy by neutralizing vascular endothelial growth factor A (VEGF). Although VEGF is known as a major regulator of wound healing and liver regeneration, the incidence of postoperative complications at these sites is unexpectedly low in patients after neoadjuvant therapy including Bev. Mechanistic studies evaluating this discrepancy are limited. Methods: 40 patients with stage IV colorectal cancer received chemotherapy with (n = 31) or without (n = 9) Bev prior to resection of liver metastases. Plasma samples were taken before and 1-3 days after surgery. Additionally, intraabdominal (abd) and subcutaneous (sc) drainage samples were collected in 24 patients. The percentage of Bevacizumab bound vs. free VEGF was evaluated by immunoprecipitation. Results: No increased incidence of wound healing complications or postoperative liver failure was observed in Bev treated patients as compared to chemotherapy controls. As previously reported, a significant rise in VEGF blood levels was recorded in response to neoadjuvant treatment with bevacizumab (P < 0.001). Postoperative plasma VEGF levels were also found to be significantly higher in Bev treated patients (p<0.01). In contrast, VEGF was significantly lower in abd and sc fluid of Bev treated as opposed to control patients without Bev (p<0.05). Despite this discrepancy in systemic versus local VEGF concentrations, VEGF was mostly bound by Bev in both, plasma and wound fluid. With respect to the other angiogenesis factors investigated in wound fluid, Bev treated patients had substantially elevated PD-ECGF levels as compared to controls. Conclusions: VEGF feedback production in response to neoadjuvant Bev therapy was detectable by an increase in circulating (systemic) VEGF in patient plasma prior to surgery and in the postoperative period. However, at the actual site of wound healing, we found significantly reduced VEGF values in Bev patients, and the remaining VEGF was inactivated by Bev. Therefore, wound healing seems to proceed independent of VEGF and might be supported by other, compensatory growth factors such as PD-ECGF.

2010 AEG Outstanding Student Professional Paper

Horizontal drains have been used since the 1930s to increase the stability of slopes by lowering the groundwater table. Horizontal wick drains represent a new technique that has proven to be effective at stabilizing slopes of fine-grained soils while being less costly and time-consuming to install than traditional polyvinyl chloride (PVC) or steel pipe drains. Their adoption has been slow in part due to uncertainty about clogging and the life span before drain replacement is required. To address these concerns, the degree of clogging and the reduction in flow rate were measured for exhumed wick drains that had been in the ground between less than 1 year and 11 years. The flow rate through the drain samples was measured under constant head conditions, and clogging was measured visually and by increase in drain mass. The results of this study suggest that drain failure does not occur during the first 11 years of use and is not anticipated during continued use in the expected field conditions. A reduction in flow rate of 85 percent was the maximum measured for the drain samples. Despite this reduction in flow rate, horizontal wick drains are able to transport at least two times more water than the surrounding soil will introduce. Though horizontal wick drains are not expected to fail due to clogging, a chart is provided to select the proper drain spacing based on soil hydraulic conductivity and required drain length, in order to prevent the flow capacity of the drains from being exceeded.

Isolation and Phylogenetic Analysis of Chromium(VI) Reducing Bacteria of a Magnetite Mine Drainage from Hebei China

A magnetite mine drainage sample collected from Han-Xing Iron mine area in Hebei Province was domesticated with potassium dichromate. Four kinds of media supplemented with 300mg/L chromium(VI) were used to isolate chromium(VI) tolerant bacteria. 10 Cr(VI) reducing strains which can tolerant at least 350 mg/L Cr(VI) and reduce the Cr(VI) efficently are screened by observing the growth station and measuring the remaining chromium (VI) concentration in media. 16S rDNA sequencing and phylogenetic analysis showed that Brevundimonas spp. are the main group of chromium(VI) tolerant bacteria in the magnetite mine drainage water sample.

Physico-Chemical Environment of Coastal Areas in the Vicinity of Lbod And Tidal Link Drain in Sindh, Pakistan after Cyclone 2a

This paper presents the results of preliminary assessment of water quality along the coastal areas in the vicinity of Left Bank Outfall Drainage (LBOD) and Tidal Link Drain (TLD) in Sindh province after the cyclone 2A occurred in 1999. The water samples were collected from various RDs of Tidal Link Drain and lakes during September 2001 to April 2002 and were analysed for salinity, nitrite, phosphate, ammonia, silicate and suspended material in water. The results of the study showed considerable variations in water quality depending upon the location along the coast in the vicinity of LBOD and RDs. The salinity ranged between 4.39-65.25 ppt in Tidal Link Drain samples whereas 2.4-38.05 ppt in samples collected from lakes. The values of suspended material at various RDs of Tidal Link Drain ranged between 56.6-2134 ppm and at the lakes between 68-297 ppm. The data of continuous monitoring at RD-93 showed the range of PO4 (8.6-25.2 µg/l), SiO3 (554.96-1462 µg/l), NO2 (0.557.2-25.2 µg/l) and NH3 (9.38-23.62 µg/l). The concentration of nutrients in water samples collected from different RDs was found in the range of PO4 (10.85 to 11.47 µg/l), SiO3 (1624 to 2635.08 µg/l), NO2 (20.38 to 44.8 µg/l) and NH3 (24.08 to 26.6 µg/l). Sindh coastal areas which situated at the north-western boundary the Arabian Sea are highly vulnerable to flood damages due to flash floods during SW monsoon or impact of sea level rise and storm surges coupled with cyclones passing through Arabian Sea along Pakistan coast. It is hoped that the obtained data in this study would act as a database for future investigations and monitoring of LBOD and Tidal Link Drain coastal waters. Keywords—Tidal Link Drain, Salinity, Nutrients, Nitrite salts, Coastal areas.

A laboratory study of colloid and solute transport in surface runoff on saturated soil

Colloids in surface runoff may pose risks to the ecosystems not only because some of them (e.g., pathogens) are toxic, but also because they may facilitate the transport of other contaminants. Although many studies have been conducted to explore colloid fate and transport in the environment, current understanding of colloids in surface runoff is still limited. In this study, we conducted a range of laboratory experiments to examine the transport behavior of colloids in a surface runoff system, made of a soil box packed with quartz sand with four soil drainage outlets and one surface flow outlet. A natural clay colloid (kaolinite) and a conservative chemical tracer (bromide) were applied to the system under a simulated rainfall event (64 mm/h). Effluent soil drainage and surface flow samples were collected to determine the breakthrough concentrations of bromide and kaolinite. Under the experimental conditions tested, our results showed that surface runoff dominated the transport processes. As a result, kaolinite and bromide were found more in surface flow than in soil drainage. Comparisons between the breakthrough concentrations of bromide and kaolinite showed that kaolinite had lower mobility than bromide in the subsurface flow (i.e., soil drainage), but behaved almost identical to bromide in the surface runoff. Student’s t-test confirmed the difference between kaolinite and bromide in subsurface flow (p = 0.02). Spearman’s test and linear regression analysis, however, showed a strong 1:1 correlation between kaolinite and bromide in surface runoff (p < 0.0001). Our result indicate that colloids and chemical solutes may behave similarly in overland flow on bare soils with limited drainage when surface runoff dominates the transport processes.

Five novel acid-tolerant oligotrophic thiosulfate-metabolizing chemolithotrophic acid mine drainage strains affiliated with the genus Burkholderia of Betaproteobacteria and identification of two novel soxB gene homologues

Five acid-tolerant thiosulfate-metabolizing bacteria were isolated from acid mine drainage samples from Garubathan, India. 16S rRNA gene analysis revealed that the strains were affiliated with the genus Burkholderia of the class of Betaproteobacteria. Comparative 16S rRNA gene sequence analyses indicated that the strains designated as GAH1 and GAH2 produced a separate phylogenetic branch having Burkholderia pyrrocinia ATCC 51958 T (96–98%) as the closest relative. Strains GAH4 and Burkholderia tropica Ppe8 T (93%) branched out separately in the phylogenetic tree. Strain GMX2 was most closely related to Burkholderia cepacia ATCC 25417 T (99.6%) and Burkholderia vietnamiensis LMG 10929 T (99%). Strain GAH5 was most closely related to B. pyrrocinia ATCC 51958 T (98%). Oligotrophy has been demonstrated in all AMD strains of Burkholderia spp. All strains showed chemolithoautotrophic and mixotrophic growth in thiosulfate. Furthermore, cell-free extracts of all test strains possessed thiosulfate and sulfite dehydrogenase activities. Phylogenetic analysis of the soxB gene revealed that GAH4 and GAH2 strains formed a novel cluster, Betaproteobacteria II, having highest similarity with Allochromatium vinosum, a member of Gammaproteobacteria II.

Effects of vegetation and fertilizer on metal and Sb plant uptake in a calcareous shooting range soil

Shooting range soils frequently contain anomalous concentrations of metals (e.g. Pb, Zn, Mn) and Sb coming from bullets which may be released into the environment. In a pot experiment, we investigated metal and Sb uptake by three plant species ( Plantago lanceolata, Lolium perenne and Triticum aestivum) growing on a calcareous shooting range soil (pH 7.8; 500 mg kg −1 Pb, 21 mg kg −1 Sb) and the uptake changes when an acidic fertilizer solution was applied to the soil. Metal and Sb solubility in the soil was determined by extraction with 0.1 M NaNO 3. In addition, we measured pH, electrical conductivity and dissolved organic carbon in drainage samples. The results showed significant increase over time of pH (from 7.8 to 8.3) and decrease of electrical conductivity and dissolved organic carbon (from 230 to ∼130 mg L −1). Fertilizer application increased NaNO 3-extractable Pb and Sb and root:shoot biomass ratio but not plant metal uptake. In T. aestivum spikes accumulated more Zn, Ni and Cu than shoots and grains. Mn and Zb uptake was correlated in L. perenne shoots. P. lanceolata, a Sb-bioindicator, did not accumulate high amounts of Sb (<1 mg kg −1).

Column bioleaching of uranium embedded in granite porphyry by a mesophilic acidophilic consortium

A mesophilic acidophilic consortium was enriched from acid mine drainage samples collected from several uranium mines in China. The performance of the consortium in column bioleaching of low-grade uranium embedded in granite porphyry was investigated. The influences of several chemical parameters on uranium extraction in column reactor were also investigated. A uranium recovery of 96.82% was achieved in 97days column leaching process including 33days acid pre-leaching stage and 64days bioleaching stage. It was reflected that indirect leaching mechanism took precedence over direct. Furthermore, the bacterial community structure was analyzed by using Amplified Ribosomal DNA Restriction Analysis. The results showed that microorganisms on the residual surface were more diverse than that in the solution. Acidithiobacillus ferrooxidans was the dominant species in the solution and Leptospirillum ferriphilum on the residual surface.

Fate of Mycobacterium avium subsp. paratuberculosis after application of contaminated dairy cattle manure to agricultural soils.

Details regarding the fate of Mycobacterium avium subsp. paratuberculosis (basonym, Mycobacterium paratuberculosis) after manure application on grassland are unknown. To evaluate this, intact soil columns were collected in plastic pipes (lysimeters) and placed under controlled conditions to test the effect of a loamy or sandy soil composition and the amount of rainfall on the fate of M. paratuberculosis applied to the soil surface with manure slurry. The experiment was organized as a randomized design with two factors and three replicates. M. paratuberculosis-contaminated manure was spread on the top of the 90-cm soil columns. After weekly simulated rainfall applications, water drainage samples (leachates) were collected from the base of each lysimeter and cultured for M. paratuberculosis using Bactec MGIT ParaTB medium and supplements. Grass was harvested, quantified, and tested from each lysimeter soil surface. The identity of all probable M. paratuberculosis isolates was confirmed by PCR for IS900 and F57 genetic elements. There was a lag time of 2 months after each treatment before M. paratuberculosis was found in leachates. The greatest proportions of M. paratuberculosis-positive leachates were from sandy-soil lysimeters in the manure-treated group receiving the equivalent of 1,000 mm annual rainfall. Under the higher rainfall regimen (2,000 mm/year), M. paratuberculosis was detected more often from lysimeters with loamy soil than sandy soil. Among all lysimeters, M. paratuberculosis was detected more often in grass clippings than in lysimeter leachates. At the end of the trial, lysimeters were disassembled and soil cultured at different depths, and we found that M. paratuberculosis was recovered only from the uppermost levels of the soil columns in the treated group. Factors associated with M. paratuberculosis presence in leachates were soil type and soil pH (P < 0.05). For M. paratuberculosis presence in grass clippings, only manure application showed a significant association (P < 0.05). From these findings we conclude that this pathogen tends to move slowly through soils (faster through sandy soil) and tends to remain on grass and in the upper layers of pasture soil, representing a clear infection hazard for grazing livestock and a potential for the contamination of runoff after heavy rains.

Detoxification of aflatoxin B1 by certain bacterial species isolated from Egyptian soil

Aflatoxin contamination of food and grain poses a serious economic and health problem worldwide. Aflatoxin B1 (AFB1) is extremely mutagenic, toxic and a potent carcinogen to both humans and livestock. A safe, effective and environmentally sound detoxification method is needed for controlling this toxin. In this study, 21 soil samples were screened from various sources with vast microbial populations using a coumarin containing medium. Eleven bacterial isolates showing AFB1 reduction activity in a liquid culture medium were selected from the screening experiments. Isolate 12-3 and 12-5, obtained from soil samples of Kafr-Zaiat Pesticide company drainage and identified to be Pseudomonas putida and Escherichia coli, reduced AFB1 by 69.3% and 58.8%, respectively, after incubation in the liquid medium at 37 °C for 72 h. The culture supernatant of these isolates was able to reduce AFB1 effectively by 76.2% and 62.5%, respectively, whereas the viable cells and cell extracts were far less effective. Factors influencing AFB1 detoxification by the culture supernatant were investigated. The highest detoxification activity for P. putida and E. coli was 83.3% and 63.8%, respectively, at pH 8 and 30 °C for 72 h. The detoxification activity was reduced at 10, 20 and 45 °C. The Mg2+, Mn2+, Se and Cu2+ ions were activators for AFB1 detoxification. However, Zn2+ ion was a strong inhibitor. Treatments with proteinase K, proteinase K plus SDS and heating significantly reduced or eradicated the detoxification activity of the culture supernatant. In conclusion, the detoxification of AFB1 by P. putida 12-3 was enzymatic and the enzymes responsible for the detoxification of AFB1 are constitutively extracellular produced. Also, the AFB1 detoxification by E. coli was conducted by enzymes as well as by cell wall binding mechanism. Both bacteria could have great potential in industrial applications.

A kinetics analysis applied to the recovery of Zn(II) content from mine drainage by using a surfactant liquid membrane

A kinetics analysis was conducted for the recovery of zinc (II) ions from a mine drainage sample by a liquid surfactant membrane containing di-(2-ethylhexyl)phosphoric acid as a carrier extractant and Span-80 as the surfactant. The extraction of metal was proportional to the concentration of carrier in the organic phase, inversely proportional to the zinc content in the feed solution, and was enhanced as the pH of the feed phase was increased. A minimum sulfuric acid content of 150 g/L in the stripping solution was necessary to favor the transport of metals from the external aqueous solution to the metal-receiving strip liquor. The experimentally observed results were analyzed by a metal extraction kinetics mechanism based on a facilitated transport model, which considers the interfacial chemical reaction between the metal and the carrier at the external interface of the liquid membrane as kinetic controlling step. The experimental results were fairly well explained by the model that takes into account th...

Leaching of Salmonella enterica in Clay Columns Comparing Two Manure Application Methods

Transfer of zoonotic bacterial pathogens through intact soil columns was monitored in an outdoor lysimeter over 36 d. Manure spiked with Salmonella enterica serovar Senftenberg was applied to either the soil surface or injected 0.08 m into the soil to compare leaching associated with the two manure application methods. The highest concentrations of S. enterica (up to 60,000 S. enterica CFU/mL) were detected on Day 1 in the first drainage samples, with measurable but declining concentrations persisting for 10 to 36 d depending on replicate columns. The total recovery of leached S. enterica in drainage samples ranged from 0.08% to 13.8%. When comparing the two application methods, there was no statistically significant difference in the leaching concentration of S. enterica at each sampling time during the study period. In addition, comparison of enumerations by selective plating and real-time polymerase chain reaction yielded similar concentrations of S. enterica, indicating that mainly viable and culturable cells were leached from the columns. When the experiment was terminated, the fluorescent dye Acid Yellow was applied to four selected columns and the distribution of dye and size of active (dye-stained) pores were measured with a digital camera and visualization software. The profiles showed that the area covered by active pores ranged from 0.1% to 3.6%. The relatively small fraction of active pores in the soil profile was consistent with the evidence of rapid transport of S. enterica and chloride in the columns.

Multi-residue Screening Method To Quantify Mycotoxins in Aqueous Environmental Samples

Mycotoxins are naturally occurring secondary metabolites of fungi colonizing agricultural products on the field or during storage. In earlier work, we have shown that two common mycotoxins, i.e., zearalenone and deoxynivalenol, can be present at significant levels in the aquatic environment. This raises the question about the relevance of a wider range of mycotoxins in natural waters. In this investigation, we present the first validated method for analysis of some additional 30 mycotoxins in drainage, river, and wastewater treatment plant effluent water. The method includes solid-phase extraction over Oasis HLB cartridges, followed by liquid chromatography with electrospray ionization triple quadrupole mass spectrometry. Absolute method recoveries for 13 of the 33 mycotoxins were higher than 70% in wastewater treatment plant effluent (at 25 ng/L), and 27 compounds had method detection limits (MDLs) below 10 ng/L. The applicability of this method is illustrated with selected data from our ongoing monitoring campaigns. Specifically and for the first time, beauvericin and nivalenol were quantified in drainage and river water samples with mean concentrations of 6.7 and 4.3 ng/L and 6.1 and 5.9 ng/L, respectively. These compounds thus add to the complex mixture of natural and anthropogenic micropollutants in natural waters, where their ecotoxicological risk remains to be evaluated.

Diversity of microbial community at acid mine drainages from Dachang metals-rich mine, China

Two acid mine drainage (AMD) samples TS and WK, which were from the Dachang metals-rich mine in Guangxi province, China, were studied using PCR-based cloning approach. A total of 44 operational taxonomic units (OTUs) were obtained from the two AMD samples. However, only three OTUs (GXDC-9, GXDC-19 and GXDC-50) detected in sample TS can also be observed in sample WK. Phylogenetic analysis revealed that the bacteria in the two samples fell into four putative divisions, which were Nitrospira, Alphaproteobacteria, Gamaproteobacteria, and Acidobacteria. Organisms of genuses Acidithiobacillus and Leptospirillum, which were in gamaproteobacteria class and Nitrospira family, were dominant in two samples, respectively. In sample TS, which was characterized by low pH, high sulfate, high iron, and high arsenide, two species ( Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans) constituted 98.22% of the entire microbial community. Compared with sample TS, the microbial community in sample WK was more diversified according to the observation. Interestedly, the Legionella species, which was rarely observed in the low-pH environment, was detected in sample WK. This work helps us to further understand the diversity of microbial community living in extreme acid mine drainages with unique geochemistry and the tolerance capability of acidophiles to heavy metal.

Estrogenicity and Nutrient Concentration of Surface Waters Surrounding a Large Confinement Dairy Operation Using Best Management Practices for Land Application of Animal Wastes

The impact of a confinement dairy operation (>2000 head) using best management practices for land application of animal wastes, on estrogenic activity (E-Screen), estrogens, and nutrients of associated surface waters and tile drain runoff were evaluated. Farm tile drain and creek samples were collected from the drainage region: above and below a municipal wastewater treatment plant located upstream from the dairy; and downstream from animal housing, parlor, and fields receiving applied wastes. Fifty-four thousand tons of waste (from approximately 1000 milking head) were applied to approximately 809 ha from April to July. Maximum estradiol equivalents (E(2)Eqs) present in tile drain samples (<or=0.257 ng/L) were 2-fold maximum creek E(2)Eqs, but only 25% of the proposed no observable effect concentration for E(2) (1 ng/L). Relative manure slurry estrogen concentrations were estrone >17alpha-E(2) > 17beta-E(2). Creek nutrient concentrations were similar above and below the dairy, with higher concentrations found in tile drain samples: tile ammonia ranged from <0.05 to 0.70 mg/L, nitrate/ite from 1.2 to 14 mg/L, and total phosphorus from 0.04 to 0.34 mg/L. No differences in estrogenic activity or nitrate/ite, ammonia, and phosphorus concentrations were detected in surface waters downstream of a large confinement dairy facility and measured nutrients were within regional norms.

Quantitative PCR assays to survey the bovine adenovirus levels in environmental samples

Previous studies suggested bovine adenoviruses (BAdVs) could be used as cattle faecal indicators. The main aim of this study was to survey the levels of BAdV in environmental samples using quantitative polymerase chain reaction (qPCR). Two qPCR assays were developed to identify and quantify BAdVs in environmental samples. BAdVs were detected in all dairy manure, and in most cases, the sample concentrations were around 10(3)-10(4) copies ml(-1). Farm tile drainage samples were also detected, but the concentrations were about 1-3 log(10) lower than the BAdV concentrations in the manure samples. The genome equivalent copy (GEC) levels of BAdV and the phage forming unit (PFU) levels of somatic phage in manure samples were comparable. Four of twenty individual cattle faeces were positive with concentrations similar to that found in the manure samples. Sequencing results confirmed the presence of BAdV in the environmental samples, and phylogenetic analysis indicated that BAdV 2 and 4 were the most prevalent serotypes in all the manure samples tested. The qPCR assays developed in this study showed higher sensitivity in detecting BAdV 1 and 2 than the previous published nested assay. The high levels of BAdV in the environmental samples may suggest it could be used for bovine faecal indicator. The significant levels of BAdV in the drainage samples may indicate the potential of surface water pollution by the manure applied to farm fields. This is the first study that reports the quantitative level of BAdV in environmental samples. These results could be useful when it comes to determining whether BAdV could be utilized as a bovine faecal indicator.

A Comparative Study of Sterility Levels in Continuous Ambulatory Peritoneal Dialysis System

Peritonitis remains a serious risk associated with continuous ambulatory peritoneal dialysis (CAPD), although better patient education programs and such technological advances as improved automated connecting devices have greatly decreased its incidence over the past 20 years. The automated devices have a good resistance to contamination, but they rely on an external electrical power source and are not easily portable. There has, therefore, been a need for a highly sterile nonelectric manual connecting device to complement the automated devices already in use. Such a manual device has recently been developed. We compared the level of sterility after touch contamination in this new device with levels in 2 other connecting devices: a conventional device with a manual cap (JMS Co. Ltd., Hiroshima, Japan), and a powered total containment device (JMS Co. Ltd.). Five bacteria frequently causing CAPD-related peritonitis (Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans) were separately applied to the tip of each connecting device, and peritoneal washing fluid was injected as in a routine exchange. We used a membrane filter method to determine whether the route had been contaminated by the washing fluid. In the conventional device with a manual cap, 3 to 4 colony-forming units (CFUs) of S. aureus were detected in 2 of 10 drainage samples, 8 CFUs of E. coli in 1 of 10 drainage samples, and 1 CFU of E. coli in the injection fluid. In contrast, no contamination was detected in the automated connecting device or the new manual cap device. This study confirmed that the new device has a risk of touch contamination lower than that of the conventional manual cap device and equal to that of the automated device. Being easily portable and not reliant on an external power source, the new device should be useful in various situations.