Application of An Organic Plant-Derived Binder in the Fabrication of Diatomaceous Earth Waste-Based Membranes for Water Purification Systems

MRS Advances ◽  
2020 ◽  
Vol 5 (26) ◽  
pp. 1339-1348
Author(s):  
Mary T. Simiyu ◽  
Francis W. Nyongesa ◽  
Bernard O. Aduda ◽  
Zephania Birech ◽  
Godwin Mwebaze

ABSTRACTThis work reports on the use of diatomaceous earth (DE) waste and organic binder derived from Corchorus olitorius, locally known as “Mrenda” in the design of an efficient water filtration membranes. Charcoal powder was incorporated to enhance the porosity of the membrane. The firing was done at temperatures varying from 700.0 °C to 1150.0 °C. The DE waste samples comprised 79.0% silica (by mass) and 11.0% total flux content compared to porter’s clay that had 50.0% silica, 28.8% AL2O3 and 7.0% total flux content. On the other hand, the “Mrenda” binder contained 6.5% total organic matter. The use of the plant-derived binder enhanced the mechanical strength of the greenware by 52.7% and the fired membranes by 152.2%. The fabricated DE waste-based membranes were 15.0% stronger than clay-based ceramic membranes prepared under similar conditions. A sintering temperature of 900.0 °C was optimal in producing porous membranes for filtering of 4.1 liters of water per hour. The pore diameter of the membranes fabricated from DE waste only ranged between 2.0 nm – 99.0 nm. On micro-organisms filtering efficacy, the DE waste-based membranes and those fabricated with 5.0% charcoal were 99.9% and 88.4% effective in the removal of E. coli and Rotavirus respectively.

2011 ◽  
Vol 24 (No. 6) ◽  
pp. 261-267 ◽  
Author(s):  
K. Lapišová ◽  
R. Vlček ◽  
J. Klozová ◽  
M. Rychtera ◽  
K. Melzoch

The separation of stillage was tested by means of the pilot plantARNO600-BIO using three-channel ceramic membranes with the pore diameter range from microfiltration to ultrafiltration (1.4 µm–5 kDa). The permeate from the last membrane step was able to be recycled as technological water. The best results were achieved in the arrangement of series using 0.2 µm membrane as the first step supplemented by ultra-filtration membranes (50 kDa and 15 kDa), predominantly, where the reduction of the chemical oxygen demand (COD) extended 80%. With this process, we try to get some advantages over the conventional process in terms of eliminating both land and energy costs for the wastewater treatment process and improving the quality of the discharge water. The main goal in this study is to analyse different separation steps and conditions to find both the best separation options for the decrease of the final volume of distillery stillage, and the way how to make the bio ethanol production more profitable.  


2019 ◽  
Vol 11 (20) ◽  
pp. 18268-18275
Author(s):  
Hidenori Kuroki ◽  
Alexey Gruzd ◽  
Igor Tokarev ◽  
Taras Patsahan ◽  
Jaroslav Ilnytskyi ◽  
...  

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1752
Author(s):  
Blanca Jalvo ◽  
Andrea Aguilar-Sanchez ◽  
Maria-Ximena Ruiz-Caldas ◽  
Aji P. Mathew

This article presents a comparative study of the surface characteristics and water purification performance of commercially available cellulose nonwoven fabrics modified, via cast coating, with different nano-dimensioned bio-based carbohydrate polymers, viz. cellulose nanocrystals (CNC), TEMPO-oxidized cellulose nanofibers (T-CNF), and chitin nanocrystals (ChNC). The surface-modified nonwoven fabrics showed an improvement in wettability, surface charge modification, and a slight decrease of maximum pore size. The modification improved the water permeance in most of the cases, enhanced the particle separation performance in a wide range of sizes, upgraded the mechanical properties in dry conditions, and showed abiotic antifouling capability against proteins. In addition, T-CNF and ChNC coatings proved to be harmful to the bacteria colonizing on the membranes. This simple surface impregnation approach based on green nanotechnology resulted in highly efficient and fully bio-based high-flux water filtration membranes based on commercially available nonwoven fabrics, with distinct performance for particle rejection, antifouling and antibacterial properties.


1997 ◽  
Vol 35 (11-12) ◽  
pp. 249-252 ◽  
Author(s):  
G. J. Medema ◽  
M. Bahar ◽  
F. M. Schets

Oocysts of Cryptosporidium parvum can survive for several months in surface water, one of the main factors determining their success in environmental transmission and thus their health hazard via water. Several factors in the environment, e.g. temperature, presence of predators and exo-enzymes will probably influence oocyst survival. The high persistence of oocysts may also limit the value of traditional faecal indicator bacteria. The aim of this study was to determine the rate at which C parvum oocysts, E coli, faecal enterococci and C perfringens spores die in surface water and the influence of temperature and the presence of autochthonous (micro)organisms on the die-off rate. Microcosms with autoclaved river water were inoculated with the organisms. Microcosms with untreated river water were inoculated with concentrated primary effluent containing the bacteria and with C parvum oocysts. Microcosms were incubated at 5°C or 15°C at 100rpm. Viability of oocysts was monitored by in vitro excystation and dye-exclusion; viability of the bacteria was determined on appropriate selective media. When pseudo first-order die-off kinetics were assumed, the die-off rate of oocysts at 5°C was 0.010 log10/d and at 15°C, 0.006–0.024 log10/d. These rates underestimate die-off since oocyst disintegration was not accounted for. Incubation in autoclaved or untreated water did influence the die-off rate of oocysts at 15°C but not at 5°C. The die-off rate of E coli and enterococci was faster in the non-sterile river water than in autoclaved water at both temperatures. At 15°C, E coli (and possibly E faecium) even multiplied in autoclaved water. In untreated river water, the die-off of E coli and enterococci was approximately 10x faster than die-off of oocysts but die-off rates of C perfringens were lower than those of oocysts. As for oocysts, die-off of the bacteria and spores was faster at 15°C than at 5°C. Oocysts are very persistent in river water: the time required for a 10x reduction in viability being 40–160d at 15°C and 100d at 5°C. Biological/biochemical activity influenced oocyst survival at 15°C and survival of both vegetative bacteria at 5 and 15°C. The rapid die-off of E coli and enterococci makes them less suitable as indicators of oocyst presence in water. As C perfringens survived longer in untreated river water than oocysts, it may prove useful as an indicator of the presence of C parvum.


Microbiology ◽  
2005 ◽  
Vol 151 (5) ◽  
pp. 1421-1431 ◽  
Author(s):  
Patrice Bruscella ◽  
Laure Cassagnaud ◽  
Jeanine Ratouchniak ◽  
Gaël Brasseur ◽  
Elisabeth Lojou ◽  
...  

The gene encoding a putative high-potential iron–sulfur protein (HiPIP) from the strictly acidophilic and chemolithoautotrophic Acidithiobacillus ferrooxidans ATCC 33020 has been cloned and sequenced. This potential HiPIP was overproduced in the periplasm of the neutrophile and heterotroph Escherichia coli. As shown by optical and EPR spectra and by electrochemical studies, the recombinant protein has all the biochemical properties of a HiPIP, indicating that the iron–sulfur cluster was correctly inserted. Translocation of this protein in the periplasm of E. coli was not detected in a ΔtatC mutant, indicating that it is dependent on the Tat system. The genetic organization of the iro locus in strains ATCC 23270 and ATCC 33020 is different from that found in strains Fe-1 and BRGM. Indeed, in A. ferrooxidans ATCC 33020 and ATCC 23270 (the type strain), iro was not located downstream from purA but was instead downstream from petC2, encoding cytochrome c 1 from the second A. ferrooxidans cytochrome bc 1 complex. These findings underline the genotypic heterogeneity within the A. ferrooxidans species. The results suggest that Iro transfers electrons from a cytochrome bc 1 complex to a terminal oxidase, as proposed for the HiPIP in photosynthetic bacteria.


2016 ◽  
Vol 57 (4) ◽  
pp. 45-51 ◽  
Author(s):  
Zbigniew Dąbrowiecki ◽  
Małgorzata Dąbrowiecka ◽  
Romuald Olszański ◽  
Piotr Siermontowski

AbstractWhen working in chemical or biological environments, contamination is an extremely dangerous issue for the rescue services of the fire department, police and the army.Modern protective overalls worn by fire fighters or dry “Viking” diving suits made from neoprene or nylon covered with polyurethane, have been proven to ensure sufficient protection. However, once the contaminated area is left, there is a need to perform decontamination of the external and internal surfaces of the protective overalls; in order to ensure the clothing continues to offer a high level of comfort and to retain the durability of said protective clothing, it is of course also necessary to perform a drying procedure.Moreover, there is a risk of a transfer of pathogenic micro-organisms between persons utilising the same protective clothes, particularly in the case of expensive specialist suits. Micro-organisms which may potentially spread through clothing include intestinal bacteria, such as: Salmonella, Shigella, Campylobacter, E. coli (including E. coli O157), C. difficile, viruses inducing infections of the upper respiratory tract and alimentary tract (noraviruses, rotaviruses, adeno and astroviruses). The risk of infection also involves the presence of the flu viruses, herpesviruses and pathogens transferred through skin, such as S. aureus (including MRSA), yeast-like fungi (Candida albicans), fungal strains inducing Tinea pedis and Tinea corporis [1]. Pathogenic micro-organisms can easily transfer from fabric surface onto the body of a person wearing protective clothing.From the numerous available techniques of decontamination of surfaces, equipment and protective clothing we propose to use for this purpose gaseous hydrogen peroxide (H2O2), a very effective biocidal agent. In field conditions, typical for the activities of rescue crews of the fire department, police and army we assume utilisation of a portable decontamination chamber enabling performance of a complete decontamination process.The process lasting approximately 3 hours encompasses 3 phases:• Drying phase;• Decontamination with gaseous hydrogen peroxide;• Catalytic combustion phase of hydrogen peroxide residues to a level safe for the environment.The integrated humidity and H2O2level sensors ensure automatic control of the entire process and the unique distribution system of gaseous H2O2secures full accessibility of the biocidal agent to the external surface of protective clothing as well as its interior. Moreover, the container allows for the conduction of the complete decontamination of the rescue equipment, night vision devices, binoculars, field telephones, radio stations, etc. Upon decontamination cycle completion, we obtain a completely dried suit which can be safely used by another crew member.


Membranes ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 711
Author(s):  
Wan Fan ◽  
Dong Zou ◽  
Jingrui Xu ◽  
Xianfu Chen ◽  
Minghui Qiu ◽  
...  

Support is a necessary foundation for ceramic membranes to achieve high performance. Finding the optimum balance between high performance and low cost is still a significant challenge in the fabrication of ceramic supports. In this study, low-cost fly ash-based ceramic supports with enhanced performance were prepared by the addition of bauxite. The pore structure, mechanical strength, and shrinkage of fly ash/bauxite supports could be tuned by optimizing the bauxite content and sintering temperature. When the sintering temperature and bauxite content were controlled at 1300 °C and 40 wt%, respectively, the obtained membrane supports exhibited a high pure water permeance of approximately 5.36 m3·m−2·h−1·bar−1 and a high bending strength of approximately 69.6 MPa. At the same time, the optimized ceramic supports presented a typical mullite phase and excellent resistance to acid and alkali. This work provides a potential route for the preparation of ceramic membrane supports with characteristics of low cost and high performance.


Author(s):  
O. Shkromada ◽  
Yu. Dudchenko ◽  
T. Necherya ◽  
I. Abubakari Kavla

In this field, complex disinfectants were contrasted using effective concentrations against bacteria and spore-forming microorganisms. A significant problem for the owners is the emergence of resistance of strains of microorganisms in the existing production and the same disinfectants. Investigation of trusted working concentrations of disinfectants that do not have a corrosive effect on metal structures. According to the results of research and production, contrast is an effective disinfectant for reducing E. coli and S aureus at 0,3 – 0,5% concentration at exposure for 30 min. and consumption of 100 - 400 cm3 / m2. Laboratory researches were carried out in laboratories of microbiological faculties of veterinary medicine of Sumy National Agrarian University. Disappearance gaps and disinfection on the market in Kyiv. Samples were drawn in the refrigerators from the walls, ceilings and floors. Refrigerated chambers made of stainless steel are made up of rubber and plastic elements. Metals are very vulnerable to corrosion with more concentrated acids and alkali. This was taken into account when choosing a disinfectant and its effective organizations. As a disinfectant used the drug contrast (manufacturer PE "Kronos Agro", Ukraine). The disinfectant was taken at a dose of 100 ml per 1 m2. To produce the culture was prepared basic products containing 1000 mg of the drug in 1 ml of distilled water. The experimental solutions were prepared for study with the main formulations developed. Representatives had extraordinary effects. The  disks were leaked through the disinfectant to obtain a zone of retention of high bacteria and fungi. The reliability of disinfectant destroying the micro-organisms of E. coli and S. aureus test cultures was also known. For the trusted production preparations, the contrast at the trusted enterprises was carried out by the rehabilitation of the premises of the educational laboratory of the Sumy National Agrarian University (premises for animals, dairies, refrigeration chambers). Renovation and test activities were performed at 0,1, 0,25 and 0,5 % of exposed contrast with exposure for 60, 30 and 10 min. the disinfectant was consumed 250 cm3 / m2. Upon completion of the studies, the investigated tests were investigated with distilled water (flow rate - 1000 cm3 / m2). Water that has been washed away test products, presented in specially prepared capabilities. Test results for this after disinfection were also investigated with distilled water, which was found on the disinfectant. To study the corrosion activity of the disinfectant used metal plates 1h1sm2. The metal samples were welded to the fifth mark after the commission before and after the study. 0,5; 1,0; 1,5; 2,5 % contrast solutions were used in the study. For comparison, in the experiments used 2% of productive. M. bovis mycobacterial cultures were grown on Pavlovsky's glycerol medium. The bacterial culture was transferred into sterile vials and sterile isotonic material containing 0,05 cm3 / mg was added. A large amount of delay zone in Petri dishes containing 0,5 % of S. aureus disinfectant, 3,5 times S. cholerase 1,8 S. Enteritidis 2 more than 0,5% formal form . Higher indicators of bacterial properties of the disinfectant contrast at a concentration of 0,5%.


Author(s):  
Rachana Kanaujia ◽  
Amit Kumar ◽  
Malay Bajpai

Background: Urinary tract infections (UTIs) are one of the most common infections. For treatment of UTIs, there are limited antibiotics due to increased resistance among uropathogens. Two older antibiotics; Nitrofurantoin and Fosfomycin have become novel oral therapeutic options against uropathogens. Aim of the study was to identify UTI causing micro-organisms and evaluate in-vitro activity of nitrofurantoin and fosfomycin against most common isolated organism (E. coli).Methods: Results of urine samples culture and susceptibility testing over a period of 1 year were analysed and included in this study.Results: Micro-organisms were isolated from 568 urine samples. Most commonly isolated organism was Escherichia coli (40.50%), followed by Klebsiella spp. (20.07%) and Staphylococcus spp. (17.07%). Susceptibility of E. coli to nitrofurantoin and fosfomycin was 91.74% and 65.65% respectively. Conclusion: Good activity of nitrofurantoin and fosfomycin against E. coli indicates that these two drugs are potential therapeutic alternatives for urinary tract infections.


2009 ◽  
Vol 60 (2) ◽  
pp. 389-398
Author(s):  
Hoei-Yuan Hwang ◽  
Hung-Yuan Fang

Ta-an Beach in Taichung County, central Taiwan, was found to have exceeded 1,000 CFU/100 ml, 51% of the total monitoring records. It is difficult to identify the contamination source using traditional Escherichia coli and Enterococci analysis. Therefore, a more advanced method known as molecular biotechnology is adopted in this study to diagnose the sources of E. coli at Ta-An Beach. After comparing several different groups of micro-organisms in water samples, we know that there are E. coli and Bacillus. This shows that the beach water quality is indeed affected by contamination from land drainage, and the numbers of E. coli and non-E. coli coliform in land drainage is far greater than that normally found at the beach. The analytical methods and techniques used in this study were not significantly different from the results detected using standard data analysis. The proposed method has high stability and reliability, providing ways to track and identify future of contamination.


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