Oxidation by-products of the C.I. Direct Blue 106 dye after ozonation

Oksidacijski nusprodukti bojila C.I. Direct Blue 106 nakon ozonizacije U radu je istražena oksidacija često upotrebljavanih oksazinskih direktnih bojila C.I. Direct Blue 106 (Direct Dye 106) u vodenim otopinama (600 mg L-1) pomoću ozona. VIS spekti su pokazali degradaciju oksazinskih skupina u početnoj strukturi Direct Dye 106. Oksidacijski nusprodukti, poput sulfata, nitrata, nitrita, kloridnih iona i spojeva fenola su identificirani pomoću MS-MS i LC-MS analiza. Provedena ispitivanja toksičnosti na dafnije (vodenbuhe) nakon ozonizacije otpadne vode koja je sadržala Direct dye 106 je potvrdio da nusprodukti nemaju toksične karakteristike.The oxidation of the often used oxazine direct dye C.I. Direct Blue 106 (Direct Dye 106) in an aqueous solution (600 mg L-1) by ozonation was investigated. VIS spectra showed degradation of the oxazine groups in the initial Direct Dye 106 structure. The oxidation by-products, such as sulphate, nitrate, nitrite, chloride ions and phenolic compounds, were identified by MS-MS and the LC-MS analyses. After ozonation the wastewater containing the Direct Dye 106 showed no toxic characteristics, according to Daphnia magna test (24 h- EC50 > 75%)

The decoloration of waste water after dyeing by the coagulation and flocculation

Odpadne barvalne kopeli po barvanju celuloznih vlaken z reaktivnimi barvili so zelo obarvane, saj vsebujejo večje količine hidroliziranih barvil. V raziskavi smo proučevali učinkovitost postopkov koagulacije in flokulacije za čiščenje odpadnih barvalnih kopeli neposredno po barvanju viskozne tkanine po postopku izčrpavanja. V raziskavo so bila vključena tri monofunkcionalna vinilsulfonska barvila, ki jih izdelovalci barvil priporočajo za t.i. kombinacije trikromi. V eksperimentalnem delu smo za preliminarne raziskave razbarvanja uporabili štiri anorganske koagulante ($FeCl_3$, $Ca(OH)_2$, $Fe_2(SO_4)_3$ in $Al_2(SO_4)_3$ · $18H_2O$) in komercialni organski flokulant, posamezno in v kombinaciji. V nadaljevanju smo se glede na začetne rezultate osredotočili na uporabo samega organskega flokulanta. Proučevali smo vpliv pH medija na učinkovitost čiščenja in optimirali količino uporabljenega flokulanta. Učinek fizikalno-kemičnega čiščenja smo ovrednotili spektrofotometrično z določanjem koncentracije barvil in nekaterih sumarnih ekoloških parametrov v odpadnih barvalnih kopelih pred čiščenjem in po njem. Rezultati raziskave so pokazali, da je z uporabo koagulanta učinek razbarvanja uporabljenih reaktivnih barvil več kot 90 odstotkov, z nadaljnjo filtracijo (0,45 μm stekleni filter) pa se učinek poveča do 99,5 odstotka.In most cases, after dyeing structurally complex viscose fabrics with reactive vinylsulphonic dyes, waste water contains a high amount of hydrolized dyes. The objective of the research was to study the efficiency of coagulation and flocculation for the removal of colour from waste water directly after dyeing cellulosic fabric in the exhaustion procedure. Three mono-functional vinylsulphonic dyes, recommended by the producers for the so-called "trichrom" combinations, were used in the research. In the experimental work, four inorganic coagulants ($FeCl_3$, $Ca(OH)_2$, $Fe_2(SO_4)_3$ and $Al_2(SO_4)_3$ · $18H_2O$) and a commercial organic flocculant were used. With regard to the results of the preliminary experiments, further research was focused to a commercial organic flocculant. The influence of pH was studied and the optimal amount of flocculant was determined. The efficiency of physical-chemical treatment of a dyed waste water was evaluated spectrophotometrically. The results of the research showed that by using the commercial flocculant 90% of decoloration of the used reactive dyes was obtained, and by using an additional 0.45 μm fibreglass filter even 99,5% of colour removal could be achieved

Use of a stable carbon isotope to assess the efficiency of a drinking water treatment method with CO2

CO2 gas with a special isotopic signature (?13C = -35.2% vs. VPDB) was used as a marker to evaluate the efficiency of a drinking water treatment method and the effect of an ultrasonic (US) stirrer. This treatment was developed to prevent precipitation and corrosion effects in water-supply systems. The research work was performed using a laboratory-scale pilot plant that was filled with tap water. The stable isotope analyses of ?13C-DIC (Dissolved Inorganic Carbon) in the water samples indicated that the maximum content of added CO2 gas in DIC was in the range of 35 to 45%. The use of the US stirrer during the entire experiment decreased the method\u27s overall efficiency by 10%, due to degassing at a late stage of the experiment but accelerated the dissolution process in the early experimental stage

Textile wastewater cleaning with O3O_3 and H2O2/O3H_2O_2/O_3 process

V članku sta predstavljena postopka ozoniranje ($O_3$) in $H_2O_2/O_3$, kot dva izmed učinkovitejših postopkov za čiščenje tekstilnih voda. Podane so različne sestave in lastnosti barvalnih kopeli in odplak, predstavljeni so konvencionalni postopki čiščenja ter njihove slabosti. Poglobljeno sta prikazana in razložena postopka ozoniranja in $H_2O_2/O_3$ ter pregled literature, ki se nanaša na ozoniranje in $H_2O_2/O_3$ postopek čiščenja tekstilnih barvalnih kopeli, ki vsebujejo barvila z različnimi kromofornimi skupinami. V nadaljevanju članka je podana učinkovitost postopka ozoniranja in $H_2O_2/O_3$ pri različnih eksperimentalnih pogojih za razbarvanje in zniževanje ekoloških parametrov. Iz pregleda literature je razvidno, da se postopka ozoniranje in $H_2O_2/O_3$ veliko uporabljata za odstranjevanje reaktivnih, kislih in direktnih barvil. Manj podatkov je o bazičnih, disperznih in kovinsko-kompleksnih barvilih.The paper describes the ozonation ($O_3$) and $H_2O_2/O_3$ process as two efficient methods for cleaning textile effluents. The composition and characteristics of differently coloured dyebath effluents and wastewaters, as well as conventional processes and their disadvantages are stated. The presentation of the ozonation and $H_2O_2/O_3$ process reactions and a review of applications for textile dyebath effluents loaded with different dye types of various chromophore groups are given precisely. Furthermore, the paper states the ozonation and $H_2O_2/O_3$ process efficiency for the removal of various dye types at different experimental conditions. The literature review shows that the ozonation and $H_2O_2/O_3$ process are mainly used for reactive, acid and direct dyes treatment. Less information is available on basic, disperse and metal-complex dyes

Enzymatic Hydrolysis of Textile and Cardboard Waste as a Glucose Source for the Production of Limonene in Escherichia coli

Cellulose containing textiles (cotton) and cardboard/carton waste represent a large reservoir of untapped organic carbon. These wastes have enormous potential for use as carbon feedstock in industrial biotechnological processes. Essentially, cotton/cardboard (CC) waste is pure cellulose (with some additives) in the form of polymerised glucose consisting of β-(1→4)-linked D-glucose subunits. One of the largest and most diverse classes of natural chemicals that can be produced from glucose are terpenes with a wide range of applications as flavours, fragrances, pharmaceuticals, biopesticides, and biofuels. Here we have investigated the bioconversion of CC waste into the exemplary terpene limonene as a proof of concept. Six different CC waste streams were enzymatically hydrolysed and used to produce limonene using the Escherichia coli (E. coli) microbial cell factory. The D-glucose content in the CC hydrolysate (glucose juice) was determined and then metabolised by E. coli via a manipulated heterogeneous biolipid synthesis pathway (the mevalonate pathway) to produce limonene. This study represents an important proof of concept for the production of terpenes from hydrolysed CC waste streams

Izboljšanje kvalitete podzemne vode z uvajanjem ogljikovega dioksida

The presented research work is focused on the development of an innovative way of economically improving the quality of underground water by the application of carbon dioxide. The basic pilot plant was developed with the idea of applying carbon dioxide in order to maintain the carbonate equilibria in water, pumped from under the ground. The optimal content of this natural component in underground water, used in urban areas for different purposes (e.g. drinking water, heating systems etc), simultaneously prevents corrosion and precipitated mineral deposits. The adaptation of an existing pilot plant started with operational testing and preliminary measurements. An appropriate sensor system for the online monitoring of the tap waterćs heating process measuring parameters such as the temperature, the concentration of dissolved carbon dioxide, the conductivity and the pH value was built in. Different amounts of carbon dioxide were applied during the two experimental stages. The composition of the water was regularly analysed using automatic titration and ionic chromatography. The gas-dosing control in the first phase was volumetric. Due to an observed inaccuracy in the gasdosing system, the volumetric dosing control was replaced with a system for the mass control of the introduced gas. Closing the system was considered to be suitable, as the water composition remained almost constant during the entire experiment. Improvements to the gas-dosing control and the closing of the system were carried out in the final phase of the pilot plant\u27s adaptation. Further measurements were made in different seasons to test the seasonal influences on underground water\u27s composition and the efficiency of the carbon dioxide supply.Predstavljeno raziskovalno delo obravnava razvoj sodobne metode za izboljšanje kakovosti podzemne vode z ekonomsko perspektivno uporabo ogljikovega dioksida. Osnovna pilotna naprava za uvajanje ogljikovega dioksida je bila razvita z namenom ohranjanja karbonatnega ravnotežja v vodi, ki se črpa iz podzemlja. Optimalna količina ogljikovega dioksida, ki je naravna komponenta podzemne vode ob uporabi le-te v različne namene (pitna, tehnološka voda) nudi hkrati zaščito pred odlaganjem mineralnih oblog in preprečuje korozijo. Adaptacija obstoječe pilotne naprave je v začetni fazi vključevala testni zagon in preliminarne meritve. V nadaljevanju je bil vgrajen senzorski sistem za spremljanje najpomembnejših parametrov karbonatnega ravnotežja: pH vrednosti, temperature, prevodnosti in raztopljenega CO2. Sledili sta dve seriji eksperimentov z različnimi količinami dodanega CO2. Kemijska sestava vode je bila analizirana s pomočjo ionske kromatografije in avtomatske titracije. Regulacija uvajanja plina je bila v prvi seriji eksperimentov volumetrična, v drugi seriji pa zaradi boljše natančnosti nadomeščena z masno regulacijo, tehtanjem plina. V začetku pretočni sistem je bil v drugi seriji zaprt glede na dotok sveže vode, z namenom doseganja večjih nihanj v sestavi vode. Sledili so eksperimenti v različnih letnih časih z namenom ugotoviti vpliv letnih časov na sestavo podzemne vode in učinkovitosti dodajanja ogljikovega dioksida

Statistical desgning of finishing process for viscose fabrics made from hard twisted yarn. Part 1: Finishing with reagents with low formaldehyde content

V prispevku so predstavljeni rezultati optimiranja zamreženja tkanin iz močno vite viskozne preje z reagentom z nizko vsebnostjo formaldehida - metilirane dimetiloldihidroksietilen sečnine (DMDHEU). Proučevali smo vpliv koncentracije reagenta za zamreženje, katalizatorja in neionogenega sredstva za mehčanje na nekatere uporabne lastnosti apretirane viskozne tkanine. Spremljali smo naslednje veličine: stopnjo nabrekanja viskoznih vlaken, pretržno silo, pretržni raztezek in kot razgubanja, kakor tudi vpliv postopka apretiranja na barvo viskoznih tkanin iz močno vite preje. Z uporabo reagenta za zamreženje z nizko vsebnostjo formaldehida smo dosegli: znižanje stopnje nabrekanja viskoznih vlaken za 29,5 - 62,7 odstotka, povečanje kota razgubanja za 18,4 - 144,3 odstotka, znižanje pretržne sile (za 7,2 - 22,9 odstotka) in pretržnega raztezka (za 6,2 - 20,9 odstotka). Postopek zamreženja ne povzroča zaznavnih barvnih razlik na pobarvanih tkaninah.The results of mathematical-statistical method for optimizing cross-linking of fabrics made from hard twisted yarn by using a reagent with low formaldehyde content - methylated dimethyloldihydroxyethylene urea (DMDHEU) are presented in the paper. The influence of the concentration of a cross-linking reagent, catalyst and non-ionic softener on certain applicability properties of finished viscose fabric is investigated. The following parameters were monitored: the degree of viscose fibres swelling, the breaking force, the breaking elongation and the angle of decreasing, as well as the influence of the finishing process on the colour of viscose fabrics made from hard twisted yarn. By using a cross-linking reagent with low formaldehyde content the following has been obtained: the decrease of viscose fibres swelling by 29.5 % - 62.7 %, the increase of the angle of decreasing by 18.4 % - 144.3 %, the reduction of breaking force (by 7.2 % - 22.9 %) and the breaking elongation (by 6.2 % - 20.9 %). The process of cross-linking does not cause any noticeable colour deviations on dyed fabrics