scholarly journals A new approach for the removal of unfixed dyes from reactive dyed cotton by Fenton oxidation

2019 ◽  
Vol 9 (2) ◽  
pp. 133-141
Author(s):  
Sana Islam ◽  
Irfan Ahmed Shaikh ◽  
Nabeela Firdous ◽  
Azhar Ali ◽  
Yumna Sadef

Abstract The use of fresh water in the textile wash-off process is becoming more expensive day by day due to declining water levels in the region. In this study, the potential of using Fenton oxidation in wash-off cotton reactive dyeing was investigated. The spent wash-off wastewater from one dyeing was first treated with Fenton oxidation, and then reused in several washing-offs employing widely used reactive dyes, C.I. Reactive Yellow 145, C.I. Reactive Blue 21, and C.I. Reactive Red 195. Experimental results showed that at acidic pH (3) using optimized quantities of FeSO4 and H2O2, Fenton process yielded a significant reduction (90–95%) of color in 30 minutes of treatment time. New washing-offs were then carried out in Fenton decolorized wash-off wastewater, and dyed cotton fabric samples were subjected to quality evaluations in terms of color difference properties (ΔL*, Δc*,Δb*, Δa*, ΔE*cmc) and wash fastness properties. This study concluded that after Fenton oxidation, treated liquor can be effectively reused subsequent washing-offs without compromising fabric quality parameters as ΔE*cmc was less than 1, and washing and crocking was also in the range of 4.5–5 which is commercially acceptable. Moreover, the difference in color strength in terms of k/s was also negligible.

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1484 ◽  
Author(s):  
Ewelina Płuciennik-Koropczuk ◽  
Sylwia Myszograj

Conventional quality parameters such as Chemical Oxygen Demand (COD) or Biochemical Oxygen Demand (BOD) give information about the quantity of organic matter present in wastewater, but do not give a clear indication of the biodegradability of the pollutants flowing in the WWTP. Detailed knowledge can be obtained by dividing the total COD into fractions. Fractionation and balancing of COD can be determined in various ways and with varying accuracy. Good wastewater characteristics are obtained on the basis of COD fractionation in accordance with ATV-A 131 guidelines, especially when the wastewater characteristics are in high compliance with the assumptions of the method. The article proposes a modification of the ATV-A131 method that increases the accuracy of determining the COD fraction. In order to reduce errors in the calculation of COD fractions, the value of fraction XS was calculated on the basis of the biochemical degradation rate determined in studies (k) for raw wastewater, whereas the SI fraction was calculated from the difference between SCOD and BODTot of filtered treated wastewater. BODTot of the treated wastewater was calculated taking into account the rate of biochemical degradation determined in the studies (k) for treated wastewater. The shares of individual COD fractions in raw wastewater calculated on the basis of the standard and modified procedure differed by approx. 10% in the case of suspension fractions. Modification of the methodology to determine the COD of the treated wastewater SS fraction significantly influenced the contents of all fractions in treated wastewater.


2019 ◽  
Vol 41 (6) ◽  
pp. 1138-1138
Author(s):  
Sana Islam Sana Islam ◽  
Irfan Ahmed Shaikh Irfan Ahmed Shaikh ◽  
Nabeela Firdous Nabeela Firdous ◽  
Azhar Ali and Yumna Sadef Azhar Ali and Yumna Sadef

In this study, a novel wash-off method was investigated wherein the use of Fenton’s reagent was evaluated to get rid of hydrolyzed and unfixed reactive dyes from wash-off liquor and reused in next wash-off process. After dark shade dyeing (5% o.w.f) with C.I. Reactive Blue 72, C.I. Reactive Blue 221, C.I. Reactive Red 141, C.I. Reactive Red 198, C.I. Reactive Orange 84, C.I. Reactive Orange 122, C.I. Reactive Yellow 105 and C.I. Reactive Yellow 138 , fabrics were subjected to both clean water (reference) and treated wash-off liquors (batch) and comparisons were made. Fenton reagent was proved capable to achieve 88-97% color reduction in wash-off liquor at pH 3 by using optimal dose of FeSO4 and H2O2 at room temperature. Then effectiveness of Fenton’s reagent treated wash-off was evaluated in terms of color difference values (ΔL*, ΔC*, Δh* and ΔE*), wash fastness and crocking properties. For color fastness properties the commercially tolerable value of ΔE*≤1 was observed for blue and red dyes and slightly higher value for yellow and orange dyes. Wash fastness and crocking results are almost similar for reference and batch dyed fabrics and their values ranges 4-5 on grey scale. Color strength (K/S) showed negligible difference in values indicating that fabrics absorbed almost same amount of dyestuff for each dye .Fenton method of treatment proved to be an eco-friendly and economically feasible treatment method and treated liquor can be effectively used in next dyeing, without compromising quality parameters.


2018 ◽  
pp. 5-29 ◽  
Author(s):  
L. M. Grigoryev ◽  
V. A. Pavlyushina

The phenomenon of economic growth is studied by economists and statisticians in various aspects for a long time. Economic theory is devoted to assessing factors of growth in the tradition of R. Solow, R. Barrow, W. Easterly and others. During the last quarter of the century, however, the institutionalists, namely D. North, D. Wallis, B. Weingast as well as D. Acemoglu and J. Robinson, have shown the complexity of the problem of development on the part of socioeconomic and political institutions. As a result, solving the problem of how economic growth affects inequality between countries has proved extremely difficult. The modern world is very diverse in terms of development level, and the article offers a new approach to the formation of the idea of stylized facts using cluster analysis. The existing statistics allows to estimate on a unified basis the level of GDP production by 174 countries of the world for 1992—2016. The article presents a structured picture of the world: the distribution of countries in seven clusters, different in levels of development. During the period under review, there was a strong per capita GDP growth in PPP in the middle of the distribution, poverty in various countries declined markedly. At the same time, in 1992—2016, the difference increased not only between rich and poor groups of countries, but also between clusters.


Linguistics ◽  
2020 ◽  
Vol 58 (6) ◽  
pp. 1701-1735
Author(s):  
Jeroen van de Weijer ◽  
Weiyun Wei ◽  
Yumeng Wang ◽  
Guangyuan Ren ◽  
Yunyun Ran
Keyword(s):  

AbstractIn this article we present a new approach to words of the type zigzag, chitchat, etc. in English. Such words form a formal (phonological) and functional (semantic) pattern in English. We argue that this pattern should be analysed in a construction-based approach, which has clear advantages over other approaches, e.g. analyses involving extragrammaticality or a synchronically productive reduplication process. We propose to extend the construction-based approach beyond its original scope (syntactic constructions) to words that may even no longer be morphologically complex. Finally, we make a tentative suggestion about how the difference between productive and unproductive patterns could be captured in the construction-based approach.


Author(s):  
Nives Marušić Radovčić ◽  
Damir Ježek ◽  
Ksenija Markov ◽  
Jadranka Frece ◽  
Duška Ćurić ◽  
...  

In the present work, the effect of high pressure processing (HPP) (0, 100, 200 and 300 MPa) and different treatment time (5 and 10 minutes) on the moisture uptake, cooking yield, colour and texture, as well as microbial population of chicken breast fillets was investigated. The application of high hydrostatic pressure resulted in a modification of quality parameters of chicken breast meat. By increasing pressure and time of the treatment the moisture uptake was reduced: samples treated with 300 MPa for 10 min had the lowest moisture uptake values. Cooking yield was not affected by HPP treatments. Increased pressure affected the colour by increasing L*, a* and b* values (only HPP treatment of 100 MPa in duration of 5 and 10 minutes did not affect colour of chicken breast meat). Lower pressures (100 and 200 MPa) tenderized, whereas elevated pressure (300 MPa) increased hardness in chicken breast fillets. Higher level of pressure (300 MPa) reduced bacteria count by about 3.0 – 5.3 log (CFU/g), depending on the microorganism and duration of the process.


2016 ◽  
Vol 23 (3) ◽  
pp. 265-276 ◽  
Author(s):  
Alifdalino Sulaiman ◽  
Mohammed Farid ◽  
Filipa VM Silva

Worldwide, apple juice is the second most popular juice, after orange juice. It is susceptible to enzymatic browning spoilage by polyphenoloxidase, an endogenous enzyme. In this study, Royal Gala apple juice was treated by thermosonication (TS: 1.3 W/mL, 58 ℃, 10 min), pulsed electric field (PEF: 24.8 kV/cm, 60 pulses, 169 µs treatment time, 53.8 ℃) and heat (75 ℃, 20 min) and stored at 3.0 ℃ and 20.0 ℃ for 30 days. A sensory analysis was carried out after processing. The polyphenoloxidase activity, antioxidant activity and total color difference of the apple juice were determined before and after processing and during storage. The sensory analysis revealed that thermosonication and pulsed electric field juices tasted differently from the thermally treated juice. Apart from the pulsed electric field apple juice stored at room temperature, the processed juice was stable during storage, since the pH and soluble solids remained constant and fermentation was not observed. Polyphenoloxidase did not reactivate during storage. Along storage, the juices’ antioxidant activity decreased and total color difference increased (up to 6.8). While the antioxidant activity increased from 86 to 103% with thermosonication and was retained after pulsed electric field, thermal processing reduced it to 67%. The processing increased the total color difference slightly. No differences in the total color difference of the juices processed by the three methods were registered after storage. Thermosonication and pulsed electric field could possibly be a better alternative to thermal preservation of apple juice, but refrigerated storage is recommended for pulsed electric field apple juice.


2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Darwis Darwis ◽  
Joppy D. Mudeng ◽  
Sammy N.J. Londong

This research aimed to determine the stocking density that support the best growth and survival rate of carp cultivated in aquaponic systems, and to study the water quality of carp culture with different stocking densities in aquaponic systems. The study used 12 aquaria measuring 40x40x40 cm each (water volume of 50 liters). The experimental fish are carp (Cyprinus carpio) weighing in average of 3.5 g/individual.  The fish were cultivated with different stocking densities as treatment, including A = 4; B = 7; C = 10 and D = 13 individuals/aquarium.  The fish were fed with pellet at 5%/body weight/day with a feeding frequency of two times a day. The study was conducted for 4 weeks. Data consisting of daily growth, survival and water quality parameters (temperature, pH, dissolved oxygen, ammonia, nitrite and nitrate) were measured once a week. The data obtained were analyzed by ANOVA. The results of the study showed that the difference in stocking density had no significant effect on the growth and survival of carp.  Water quality was in a reasonable range to support the growth and survival of carp cultivated with aquaponic systems.Keywords: cultivation, carp, aquaponics, stocking density, growth


2003 ◽  
Vol 1 (1) ◽  
pp. 79 ◽  
Author(s):  
F. Ribas ◽  
M.J. Cabello ◽  
M.M. Moreno ◽  
A. Moreno ◽  
L. López-Bellido

The influence of different watering regimes and of potassium applications on the quality of the melon cultivar «Pielde Sapo» was studied over a two-year period (1995 and 1996). The statistical design was a split-plot with four replications,where irrigation was the main factor and applied potassium was the secondary factor. Water levels were determinedaccording to the watering needs (NRc) calculated on the basis of crop evapotranspiration. Four irrigationtreatments were tested: 1.25 NRc; 1.00 NRc; 0.75 NRc and 0.50 NRc. Two potassium treatments were applied: K0 (0UF) and K1 (375 UF K2O in 1995 and 2 L ha–1 of a commercial product for spraying 20% of K2O in 1996). The potassiumdoses tested did not significantly influence any of the quality parameters studied except for flesh firmness inthe placenta area in 1995. Both in 1995 and 1996, the water deficit significantly reduced fruit size and flesh thickness.The severe water restriction caused a strict decrease in the percentage of fruits with recorded weight above 2.5kg. However, the weight percentage of the placenta plus the seeds in relation to the whole fruit, and the sugar content,both increased significantly in water deficient treatments. In 1995, skin thickness decreased with less irrigation whileflesh firmness increased. Following quality concerns, and in order to obtain large fruits with appropriate levels ofsugar, it is advisable to provide water amounts that meet the crop’s watering needs


2020 ◽  
Vol 9 (10) ◽  
pp. e4479108555
Author(s):  
Josué Ribeiro da Silva Nunes ◽  
Carolina Joana da Silva ◽  
Solange Kimie Ikeda-Castrillon ◽  
Nilo Leal Sander

The Pantanal wetland Mato Grosso, Brazil is among the largest floodplains in the world, with a mosaic of different habitats and rich aquatic and terrestrial biota. The habitat mosaics are found in the Chacororé and Sinhá Mariana lake System. These parental lakes of the Cuiabá River, a left tributary of the Upper Paraguay River, are known for their aquatic productivity and scenic beauty. The characteristics of these lakes and their floodplains are showed through the difference between their waters, the diversity of the aquatic macrophytes communities, fish communities and aquatic birds. Our study looked at changes in limnological variables as well as diversity of aquatic birds, during high water or flooded phase; medium water or receding phase; and the low water or dry phase. We used a temporary small lagoon in the floodplain of this system as our study area. The flood pulse is the main ecological factor affecting the Pantanal; it modifies ecological process and species composition. The water depth decreases during the season, decreasing electrical conductivity, dissolved phosphate and nitrate, water transparency, dissolved oxygen and biomass of aquatic macrophyte; and increasing calcium, total phosphorus and total nitrogen. We also observed increase in species richness and abundance of aquatic birds during the receding phase. Results show that the number of species (density) of aquatic birds increased from 10 to 30 species and the numbers of individuals from 40 to 936. The maximum richness and abundance of aquatic birds was registered during the receding phase.


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