INFLUENCE OF VARIOUS PHYSICAL-CHEMICAL TREATMENT METHODS ON MICROBIAL GROWTH IN WATER

Use of the TinO2n-1 electrode for water electrolysis process promotes the destruction of organic matter as shown by the changes in permanganate index different values of electrolysed and non electrolysed solution. Using the TinO2n-1 electrode in the electrolysis process with the presence of chlorine and bromine ions can create a lasting disinfectant effect that was demonstrated by the sharp decrease in the number of bacterial colony forming units in electrolysed solutions. Using the TinO2n-1 electrode in the electrolysis process with the presence of iodine ions can create a bacteriostatic effect which was maintained for at least 10 days in electrolysed solution

Siltuma apmaiņas procesi ķīmijas tehnoloģijā

Grāmatā aplūkoti galvenie teorētiskie priekšstati par siltuma apmaiņas procesiem. analizētas siltuma vadīšanas, konvekcijas un siltuma starošanas procesu likumsakarības. Analizētas siltuma apmainītāju konstrukcijas un darbības principi. Katras nodaļas beigās doti raksturīgāko uzdevumu risināšanas piemēri

Preparation of Electroconductive Titania Scaffolds for Bone Tissue Regeneration

Use of scaffolds as sacrificial templates for bone ingrowth is the basis of bone tissue regeneration. The main reasons for using bone scaffolds are to provide an environment for bone formation, maintain the space and at the same time supply mechanical support to the skeleton during healing process1. Bone healing can be significantly improved by applying electrical stimuli in the injured region. Thus, electrically active ceramics with three-dimensional porous structure are of interest as bone graft substitute materials2. Highly porous TiO2 ceramic scaffolds has attracted particular attention as a bone substitute material due to its excellent mechanical properties compared to other ceramic materials, biocompatibility and good osteoconductivity3. Thus, our research goal was to obtain electroconductive and 3D porous TiO2 ceramic scaffolds. Such materials could enhance bone healing process by providing electrical stimuli in the regeneration site of bone defects

Quantum Chemical Simulations of Doped TiO2 Nanotubes for Photocatalytic Hydrogen Generation

Since the experimental synthesis and characterization of nanostructured materials is quite complicated and expensive procedure, in order to perform realiable band gap engineering of doped and co-doped TiO2 nanotubes we propose relatively cheap, but efficient large-scale ab initio calculations on the electronic structure

Mathematical Model Development for Electrochemical Disinfection Efficiency Prediction

Using found equations allows water disinfection process prediction and management. Obtained equations is valid within a certain set of chosen parameters (applied current strength 0.1 – 0.4 A, chloride ions concentration 0~250 mg/L, productivity may vary from 0.055 L/min until 0.280 L/min, and sulfate ions concentration is 24 – 250 mg/L)

Water Preparation Using Electrochemical Process

Electrolysis of water under dynamic conditions and successive filtration substantially reduces the amount of iron ions in the solution. Specific work decreases if the concentration of iron ions in the initial solution is increased; if the current intensity is increased, the amount of iron ions is reduced, but the specific work of the process increases. Iron removal using electrolysis method significantly improves microbiological condition of the treated water if it contains at least 1mmol/L of chlorine ions. In water treated with electrodialysis during five days there is no development of colony forming units of bacteria Pseudomonas fluorescens. It is possible to efficiently desalinate solution. In the desalinated water there is a marked decrease (up to 1500 times) in intensity of development of colony forming units of bacteria Pseudomonas fluorescens

Preparation of Water Using Electrochemical Processes

The effect of electrolysis and electrodialysis processes on iron and calcium ion concentration and the development of microorganisms in water were studied in this work. Experiments were conducted under laboratory conditions using model solutions containing iron and calcium ions. Bacteria Pseudomonas fluorescens were used as model organism for disinfection experiments. In this work it was found that the solution electrolysis with successive filtration through quartz sand reduces total iron ion concentration 40 - 50 times. If the current intensity applied to the electrodialysis cell is increased, the total amount of iron ion concentration reduced in the solution and the specific work of the process increases. It was found that calcium and total iron ion concentration in FeSO4 and CaCO3 containing solution decreased during electrodialysis. Rapid concentration decrease is observed at the beginning of the process. Electrolysis (to remove iron) of water solution containing at least 1 mmol/L of chloride ions also significantly improves the microbiological situation. No bacteria Pseudomonas fluorescens colony forming unit development in electrolyzed water within five days was found. Using water electrodialysis it is possible to efficiently desalinate solution. The development intensity of bacteria Pseudomonas fluorescens colony forming units in desalinated water is significantly reduced (as far as 1500 times)

In vitro Bioactivity Studies of Thermally Treated Titanium Dioxide Ceramics

The ability to induce formation of bonelike apatite on artificial bone implants in the human body is vital to the successful bonding between the implants and bone tissue. Immersion in simulated body fluid (SBF) is often used in vitro method for the first indication of potential bioactivity of biomaterials. Previous studies have shown that apatite-forming ability of titania is associated not only with its chemical composition and crystallinity, but also with its textural properties. The aim of present work was to evaluate the impact of different factors (e.g. microstructure, phase composition) on in vitro bioactivity of sintered titania ceramics

Elektroķīmisko procesu izmantošana ūdens sagatavošanā

Daudzos tehnoloģiskajos procesos ūdens kvalitāte ir atkarīga no dzelzs jonu koncentrācijas un cietības. Darbā tika pētīta elektrolīzes un elektrodialīzes procesa ietekmi uz dzelzs un kalcija jonu koncentrācijas izmaiņām un mikroorganismu attīstību ūdenī. Eksperiments tika veikts laboratorijas apstākļos, izmantojot dzelzs un kalcija jonus saturošus modeļšķīdumus. Lai raksturotu ūdens apstrādes ietekmi uz mikroorganismu vairošanās intensitātes izmaiņām, izmantoja baktērijas Pseudomonas fluorescens. Darbā tika noskaidrots, ka šķīduma elektrolīze ar tai sekojošu filtrēšanu caur kvarca smilšu slānim kopējo dzelzs jonu koncentrāciju samazina no 40 līdz 50 reizēm. Pieaugot kopējai dzelzs jonu koncentrācijai izejas šķīdumos, elektrolīzes procesā patērētais īpatnējais darbs pēc strāvas samazinās. Palielinot elektrolīzes šūnai pielikto strāvas stiprumu, kopējā dzelzs jonu koncentrācija elektrolizētajā šķīdumā samazinās, bet procesa veikšanai nepieciešamais īpatnējais darbs pieaug. Veicot CaCO3 un FeSO4 saturošu šķīdumu elekrodialīzi cirkulācijas režīmā, ir novērojama gan kalcija, gan kopējās dzelzs jonu koncentrācijas samazināšanās, pieaugot procesa laikam. Straujākas koncentrācijas izmaiņas novērojamas procesa sākumā. Realizējot šķīduma, kas satur vismaz 1mmol/L hlorīda jonus, atdzelžošanu ar elektrolīzes palīdzību, tiek ievērojami uzlabots tā mikrobioloģiskais stāvoklis. Elektrolizētajā ūdenī piecu dienu laikā nav novērojama baktērijas Pseudomonas fluorescens koloniju veidojošo vienību attīstība. Veicot ūdens elektrodialīzi, iespējams efektīvi atsāļot šķīdumu. Atsāļotajā ūdenī ievērojami samazinās (līdz pat 1500 reizēm) baktērijas Pseudomonas fluorescens koloniju veidojošo vienību attīstības intensitāt