56 research outputs found
Enhanced bio-minerals production using catalysts to accelerate resource recovery in wastewater treatment plants.
The biomineralisation mechanisms of five known bio-struvite producing microbes have been
established and their ability to recover said biomineral from synthetic solutions and sludge
dewatering liquors has been trialled. There is a lack of evidence and knowledge how these
microbes perform in open culture conditions and the impact encapsulating media has on their
ability to remove and recover orthophosphate as bio-struvite. In this PhD thesis, these
microorganisms (Brevibacterium antiquum, Bacillus pumilus, Halobacterium salinarum,
Idiomarina loihiensis, Myxococus xanthus) were investigated initially, this was streamlined
into investigating encapsulated cultures of B. antiquum and B. pumilus in wastewaters under
open culture conditions. The inoculation of all five microbes in source-separated urine in open
culture conditions showed growth rates as high as 0.18 1/h and high nucleic acid proportions
>80% within 24 hours of incubation. An orthophosphate removal of up to 70% was achieved
by B. antiquum inoculations and was increased to 100% when magnesium was increased to a
1:1, P:Mg. Encapsulated cultures of B. pumilus were incubated B4.1 growth media, the removal
of orthophosphate and chemical oxygen demand was equal to suspended cell inoculations of
B. pumilus. In pure culture and open culture sludge dewatering liquors, encapsulated cultures
of B. pumilus and B. antiquum, removed 55% and 70% of the initial orthophosphate over 24
hours respectively. The minimal difference in orthophosphate removal between pure and open
culture conditions indicates that encapsulation provided an environmental advantage to the
selected microbes to out compete the native species within the open culture sludge dewatering
liquors. Suspended cell inoculations into open culture sludge dewatering liquors did not remove
any more orthophosphate than non-inoculated controls. In continuous reactors fed by open
culture sludge dewatering liquors orthophosphate removal for both encapsulated microbes
averaged between 20% and 30%, at phosphorus loading rates of 0.4 kg P/mÂł .d and 0.6 kg
P/mÂł .d. Supplementing a carbon source to the equivalent of 150 mg sCOD/L and increasing
the ratio of P:Mg to 1:1.5, achieved an orthophosphate removal of 96% on average by
encapsulated B. antiquum. Bio-struvite recovered from all open culture wastewaters was
euhedral, prismatic and tabular and was typically coated in a secondary abiotic calcium
phosphate. Micropollutant analysis showed the recovered minerals were below international
heavy metal limits and were absent from faecal coliforms, pharmaceuticals and other
micropollutants for fertilisers. Potential end users and consumers from the public and industry
showed a strong willingness to use and eat produce grown from recycling derived fertilisers.
There remains to be optimisation of the biomineralisation technique to improve the efficiency
of recovery and streamline the operational set up, however the data collected in this PhD
strongly supports the development of this technique into industry and will satisfy a growing
need for circular economies and closing the nutrient loop.PhD in Water, including Desig
Understanding the biochemical characteristics of struvite bio-mineralising microorganisms and their future in nutrient recovery
The biochemical properties of selected microorganisms (Bacillus pumilus, Brevibacterium antiquum, Myxococcus xanthus, Halobacterium salinarum and Idiomarina loihiensis), known for their ability to produce struvite through biomineralisation, were investigated. All five microorganisms grew at mesophilic temperature ranges (22â34âŻÂ°C), produced urease (except I. loihiensis) and used bovine serum albumin as a carbon source. I. loihiensis was characterised as a facultative anaerobe able to use O2 and NO3 as an electron acceptor. A growth rate of 0.15 1/h was estimated for I. loihiensis at pH 8.0 and NaCl 3.5% w/v. The growth rates for the other microorganisms tested were 0.14â0.43 1/h at pH 7â7.3 and NaCl â€1% w/v. All the microorganisms produced struvite, as identified by morphological and X-ray Powder Diffraction (XRD) analysis, under aerobic conditions. The biological struvite yield was between 1.5 and 1.7âŻg/L of media, the ortho-phosphate removal and recovery were 55â76% and 46â54%, respectively, the Mg2+ removal and recovery was 92â98% and 83â95%, respectively. Large crystals (>300âŻÎŒm) were observed, with coffin-lid and long-bar shapes being the dominant morphology of biological struvite crystals. The characterisation of the biochemical properties of the studied microorganisms is critical for reactor and process design, as well as operational conditions, to promote phosphorus recovery from waste streams
Predicting the potential of sludge dewatering liquors to recover nutrients as struvite biominerals
Phosphorus and nutrient recovery from wastewater as mineral salts can support local replenishment of fertilisers and reduce mining, contributing to the circular economy. Wastewater and related streams are rich in nutrients, however; there is need to develop bio-based processes to recover them. This study investigates the fractions of phosphorus (P) used by Brevibacterium antiquum to form struvite biominerals (bio-struvite) in wastewater sludge dewatering liquors. After 72h of incubation, 25.6 mg P/L were recovered as bio-struvite from 12.4 mg P/L organic plus condensed P and 13.2 mg P/L of ortho-phosphate. The potential of sludge dewatering liquors to recover nutrients as struvite was investigated by characterising ten types of sludge liquors (originating from primary, secondary sludge, feed to anaerobic digester and digestate, from 3 types of wastewater treatment plants) for their P fractions together with other parameters relevant for B. antiquum growth. Results indicated that liquors obtained from primary sludge, feed to anaerobic digesters and digestate were the most suitable to produce bio-struvite, as these were found to frequently have a high content of organic and condensed P, between to 276â732 mg P/L. Liquors, from all the investigated sites, presented a higher potential for bio-struvite production than with conventional struvite precipitation. This study demonstrated that B. antiquum could convert organic and condensed P into bio-struvite, and this opens up a completely new way to recover forms of phosphorus that are not typically available for nutrient recovery in a single proces
Learning outcomes from a biomedical research course for second year osteopathic medical students
Effects of Child and Maternal Histo-Blood Group Antigen Status on Symptomatic and Asymptomatic Enteric Infections in Early Childhood
Funding Information: Financial support. This work was funded by the Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development Project (MAL-ED) is carried out as a collaborative project funded by the Bill & Melinda Gates Foundation (BMGF) (BMGF-47075), the Foundation for the National Institutes of Health, and the National Institutes of Health, Fogarty International Center, whereas additional support was obtained from BMGF for the examination of host innate factors on enteric disease risk and enteropathy (Grants OPP1066146 and OPP1152146; to M. N. K.). Additional funding was obtained from teh Sherrilyn and Ken Fisher Center for Environmental Infectious Diseases, Johns Hopkins School of Medicine (to M. N. K) and the National Center for Research Resources and the National Center for Advancing Translational Sciences, National Institues of health 1UL1TR001079. Acknowledgments. We thank the participants, their families, and the study community for their dedicated time and effort to better the understanding the transmission and more enduring impact of enteric infections in early childhood. We also thank the following: Jan Vinje (Centers for Disease Control and Prevention) for critical input and manuscript review; Dr. Leah Jager for consultation regarding the statistical analysis; Dr. Ben Jann (University of Bern, Switzerland) for guidance in generating the figures; Christine Szymanski for insight and encouragement, particularly regarding Campylobacter infection and disease patency; Chris Damman and Anita Zaidi for input on early iterations of the analysis; and Dick Guerrant for final reflections.Peer reviewe
Amphibians and reptiles of the Calakmul Biosphere Reserve, MĂ©xico, with new records
We provide a list of amphibians and reptiles of the Calakmul Biosphere Reserve in the southern half of the Mexican Yucatan, in the state of Campeche. The study area was sampled through opportunistic, transect and pitfall trap surveys conducted for three successive years. These surveys resulted in a total of 2,359 amphibian and reptile encounters, belonging to 20 amphibian and 69 reptile species from 24 total families. We present herein the records for one snake, one chelonian and two salamander species not previously recorded in the area
Associations Between Eight Earth Observation-Derived Climate Variables and Enteropathogen Infection : An Independent Participant Data Meta-Analysis of Surveillance Studies With Broad Spectrum Nucleic Acid Diagnostics
Diarrheal disease, still a major cause of childhood illness, is caused by numerous, diverse infectious microorganisms, which are differentially sensitive to environmental conditions. Enteropathogen-specific impacts of climate remain underexplored. Results from 15 studies that diagnosed enteropathogens in 64,788 stool samples from 20,760 children in 19 countries were combined. Infection status for 10 common enteropathogens-adenovirus, astrovirus, norovirus, rotavirus, sapovirus, Campylobacter, ETEC, Shigella, Cryptosporidium and Giardia-was matched by date with hydrometeorological variables from a global Earth observation dataset-precipitation and runoff volume, humidity, soil moisture, solar radiation, air pressure, temperature, and wind speed. Models were fitted for each pathogen, accounting for lags, nonlinearity, confounders, and threshold effects. Different variables showed complex, non-linear associations with infection risk varying in magnitude and direction depending on pathogen species. Rotavirus infection decreased markedly following increasing 7-day average temperatures-a relative risk of 0.76 (95% confidence interval: 0.69-0.85) above 28 degrees C-while ETEC risk increased by almost half, 1.43 (1.36-1.50), in the 20-35 degrees C range. Risk for all pathogens was highest following soil moistures in the upper range. Humidity was associated with increases in bacterial infections and decreases in most viral infections. Several virus species' risk increased following lower-than-average rainfall, while rotavirus and ETEC increased with heavier runoff. Temperature, soil moisture, and humidity are particularly influential parameters across all enteropathogens, likely impacting pathogen survival outside the host. Precipitation and runoff have divergent associations with different enteric viruses. These effects may engender shifts in the relative burden of diarrhea-causing agents as the global climate changes. Plain Language Summary Diarrheal disease is a big health problem for children. It can be caused by different bugs, which can be caught more easily in certain weather conditions, though not much is understood about this because the climate varies so much from one place to the next. This study combined data from many different countries where diarrhea-causing bugs were diagnosed in children's stool. Satellites recorded what the weather was like on the day each sample was collected. Rotavirus is easiest to catch in cold weather and when water washes over the ground after rain. Dry weather also makes it and other viruses easy to catch. Bacteria spread best when the air is warm and humid, and the soil moist, though one type of E. coli can also be spread in rainwater. Climate change will make dry places drier, wet places wetter and everywhere warmer. This might lead to more diarrhea caused by bacteria and less by viruses in some places, though places with moist soil might see more of every kind of bug.Peer reviewe
Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences
The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & NemĂ©sio 2007; Donegan 2008, 2009; NemĂ©sio 2009aâb; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported
by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on
18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based
researchers who signed it in the short time span from 20 September to 6 October 2016
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