scholarly journals Determination of the color removal efficiency of laccase enzyme depending on dye class and chromophore

2019 ◽  
Vol 80 (1) ◽  
pp. 134-143
Author(s):  
Deniz İzlen Çifçi ◽  
Rıza Atav ◽  
Yalçın Güneş ◽  
Elçin Güneş
Keyword(s):  
Removal Efficiency ◽  
Enzymatic Degradation ◽  
Reactive Dyes ◽  
Reactive Dye ◽  
Color Removal ◽  
The Other ◽  
Basic Dye ◽  
Removal Efficiencies ◽  
Laccase Enzyme

Abstract The aim of this article was to clarify which type of dye chromophores could be decolorized efficiently with the use of laccase enzyme. For this purpose, enzymatic degradation of different type of dye classes (4 reactive, 2 acid and 1 basic dye) having various chromophore groups was investigated by using commercial laccase from Cerrena unicolor. It was observed that the chromophore structure of dye is very important on enzymatic color removal efficiency. According to the experimental results, it was found that color removal efficiencies (20 mg/L initial dye) were 98.7% for RB220 (0.1 g/L enzyme after 6 h), 95.1% for RB19 (0.1 g/L enzyme after 48 h), 90.8% for AR42 (0.1 g/L enzyme after 48 h) while they were 60.9% for AR114 (0.25 g/L enzyme), 58.6% for RB21 (0.5 g/L enzyme), 39.7% for RR239 (0.25 g/L enzyme) even after seven days. As a result, it can be said that the highest decolorization rate was achieved for the reactive dye having formazan copper complex (RB220) chromophore. On the other hand, the enzymatic degradation of basic dye (BB9) was found to be rather difficult compared to the acid and reactive dyes used in this study and the maximum color removal was 42.8% after seven days.

scholarly journals HOGLA LEAF AS A POTENTIAL BIO-ADSORBENT FOR THE TREATMENT OF REACTIVE DYES IN TEXTILE EFFLUENTS

2020 ◽  
Vol 4 (12) ◽  
pp. 1-7
Author(s):  
Abdul Khalque ◽  
Shaikh Ahammed ◽  
Saquib Khan ◽  
Rabiul Awual ◽  
K.Ayaz Rabbani ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Contact Time ◽  
Reactive Dyes ◽  
Textile Wastewater ◽  
Complete Removal ◽  
Reactive Dye ◽  
Textile Effluents ◽  
Typha Angustata ◽  
Colored Wastewater ◽  
Wastewater Samples

A new bio-adsorbent to remove reactive dyes from textile effluent was investigated in the present study. The adsorbent was the leaves of locally available hogla plant (Typha angustata). Initially, sunfix yellow, a reactive dye widely used in textile effluents, was used to check the removal efficiency in terms of contact time, pH of dye solution and adsorbent dosage. Complete removal (100%) of dye was achieved at adsorbent/dye ratio of 2300:1 at pH 10 with 180 minutes contact time. The adsorbent was then applied to deep colored, raw textile wastewater samples and it was found that 2.3 g of adsorbent was able to convert 100 mL of deep colored wastewater to transparent water at pH 10. Additionally, treatment by the adsorbent resulted in significant decreases in pH, BOD, COD, TS, TDS and TSS of wastewater, while improving the DO level.

scholarly journals The effect of different types of AOPs supported by hydrogen peroxide on the decolorization of methylene blue and viscose fibers dyeing wastewater

2021 ◽  
Author(s):  
Zeynep Bilici ◽  
Mohammed Saleh ◽  
Erdal Yabalak ◽  
Alireza Khataee ◽  
Nadir Dizge
Keyword(s):  
Hydrogen Peroxide ◽  
Removal Efficiency ◽  
Textile Industry ◽  
Subcritical Water ◽  
Color Removal ◽  
H2o2 Concentration ◽  
Dyeing Wastewater ◽  
Viscose Fibers ◽  
Different Types ◽  
Removal Efficiencies

Abstract Wastewater from the textile industry containing a high concentration of organic and inorganic chemicals have strong color and residual chemical oxygen demand (COD). Therefore, advanced oxidation processes (AOPs) are very good candidates to treat textile industry wastewater. In this study, we investigated the effect of different types of AOPs supported with hydrogen peroxide (H2O2) on the treatment of viscose fibers dyeing wastewater. Fenton, photo-Fenton, and Fenton supported subcritical water oxidation (FSWO) processes were chosen as AOPs to compare the treatment efficiency of viscose fibers dyeing wastewater. The effects of solution pH, Fe2+ concentration, and H2O2 concentration on the treatment of viscose fibers dyeing wastewater were tested. The maximum color and COD removal efficiency was obtained corresponding to pH 2.5 for all oxidation methods when MB dye solution was used. However, the maximum efficiencies were obtained at pH 3.0 for real textile wastewater decolorization. The MB dye removal efficiency was increased to 97.22, 100, and 100% for Fenton, photo-Fenton, and FSWO processes, respectively, when the addition of H2O2 concentration was adjusted to 125 mg/L. However, the maximum color removal efficiencies of viscose fibers dyeing wastewater were obtained 56.94, 61.26, 64.11% for Fenton, photo-Fenton, FSWO processes, respectively. As a result, the FSWO showed maximum color removal efficiencies.

Treatment of domestic wastewater mixed with crushed garbage and garbage washing water by advanced gappei-shori johkaso

1997 ◽  
Vol 36 (12) ◽  
pp. 175-182 ◽  
Author(s):  
Toshihiro Sankai ◽  
Guoji Ding ◽  
Noritoshi Emori ◽  
Satoshi Kitamura ◽  
Kensho Katada ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Domestic Wastewater ◽  
The Other ◽  
Small Scale ◽  
Anaerobic Filter ◽  
Other Hand ◽  
Removal Efficiencies ◽  
Washing Water

By using an advanced anaerobic filter-contact aeration Gappei-shori Johkaso (AFAJ), a small-scale wastewater unit used in Japan, experiments of the treatment of the wastewater mixed with domestic wastewater and disposer wastewater which came from washing water of crushed garbage by disposer were made. After the introduction of disposer wastewater into domestic wastewater, BOD, TN and SS loads increased to 1.7 times, 1.1 times and 1.7 times, respectively. Results showed that in the 5-person-use type AFAJ, no remarkable decrease appeared to the BOD and SS removal efficiencies after introduction of disposer wastewater into domestic wastewater, however, TN removal efficiency decreased significantly. As a result, effluent BOD and TN concentrations were much higher than 20 mg·l−1. On the other hand, the 7-person-use type AFAJ, whose volume was 35 % bigger than that of the 5-person-use type AFAJ, could treat the above wastewater to be less than 20, 10 and 20 mg·l−1, respectively. In addition, it was shown that not many changes took place in the kinds and occurrence frequencies of protozoa and metazoa after the addition of the disposer wastewater, which suggested that the addition of disposer wastewater had increased the BOD and SS loads while it did not lead to much change in the component of the domestic wastewater.

Removal of Trace Heavy Metals from Sewage Using the Lime-Magnesium Process

1978 ◽  
Vol 13 (1) ◽  
pp. 149-160
Author(s):  
W.K. Oldham ◽  
B.H. MacLean
Keyword(s):  
Heavy Metals ◽  
Metal Ions ◽  
Removal Efficiency ◽  
The Other ◽  
Lime Treatment ◽  
Trace Heavy Metals ◽  
Ph Values ◽  
Treatment Conditions ◽  
Removal Efficiencies

Abstract The research described in this paper is directed toward optimizing conventional lime precipitation of heavy metals by the addition of small quantities of magnesium. Specifically, jar tests were performed to evaluate the effectiveness of adding various concentrations of Mg2+ to both raw sewage and primary effluent to improve the precipitation of metal ions at various reaction pH values. The desired pH levels (10.0, 10.6 and 11.4) were obtained by the addition of lime. General results of the study, using Cr3+, Cu2+, Pb2+, Ni2+ and Zn2+ in concentrations of 0.5, 2.5 and 5.0 mg/l, indicated the following: 1. as expected, the higher the reaction pH, the greater the removal efficiency; 2. for a given reaction pH, the presence of some added Mg++ increased the removal efficiency for all metals tested except Ni2+; 3. on the average, a lime dosage of 220 mg/l (reaction pH=10.6) coupled with an Mg2+ concentration of 30 mg/l, give equivalent removals to high lime treatment at 400 mg/l (reaction pH=11.4); 4. the removal efficiencies varied between 10% and 35% for Ni2+, while the other metals gave results of 35% to 95%, depending upon treatment conditions. It can be concluded that the addition of Mg2+ does indeed enhance the removal of many heavy metals although more work is needed to optimize the combinations for a given type of sewage and to subsequently investigate relative economics.

Effect of chemical structures of reactive dyes on color removal by an anaerobic-aerobic process

2000 ◽  
Vol 42 (3-4) ◽  
pp. 377-382 ◽  
Author(s):  
W. Luangdilok ◽  
T. Panswad
Keyword(s):  
Phosphorus Removal ◽  
Carbon Sources ◽  
Reactive Dyes ◽  
Reactive Dye ◽  
Color Removal ◽  
Synthetic Wastewater ◽  
Anthraquinone Dyes ◽  
Chemical Structures ◽  
Very High ◽  
Direct Adsorption

An Anaerobic/Aerobic SBR system was used to treat a synthetic wastewater with glucose and acetic acid (1000 mg/l COD) as carbon sources together with 20 and 100 mg/l of four different reactive dyes: disazo vinylsulphonyl, anthraquinone vinylsulphonyl, anthraquinone monochlorotriazinyle and oxazine. The decolorization efficiencies of the first three dyes at the 20 mg/l dye concentration were 63, 64 and 66%, respectively, and at the 100 mg/l dye concentration were 58, 32 and 41%, respectively. For the disazo dye, two color removal rates were evident, with the initial rate in the first two hours of the anaerobic stage higher than the latter. For the two anthraquinone dyes, only one rate of color removal was seen. For the oxazine dye, a high decolorization was observed in the reactor, but when disturbed, the color re-appeared for unexplainable reasons. The phosphorus removal efficiencies were 78, 52, 41 and 96% for the four dyes of 20 mg/l, respectively, while the corresponding numbers for the 100 mg/lcondition were 48, 48, 48 and 42%, respectively, and different types of dyes had different impacts on the phosphorus removal performance. COD and TKN removals were very high, i.e., 90–99 percent. The disazo reactive dye was decolorized by the reductive reaction, which resulted in the cleavage of the azo bond. Meanwhile, the decolorization of anthraquinone dyes is believed to be through the direct adsorption of dyes on to the floc materials.

The Removal of Color from Fuchsin Basic Dye Wastewater Using Activated Carbon

2011 ◽  
Vol 356-360 ◽  
pp. 2616-2619
Author(s):  
Li Yi Ye ◽  
Xiao Xuan Zhang ◽  
Ying Wu Yin ◽  
Song Tu ◽  
Yong Sha
Keyword(s):  
Activated Carbon ◽  
Removal Efficiency ◽  
Adsorption Process ◽  
Color Removal ◽  
Dye Wastewater ◽  
Initial Concentration ◽  
Basic Dye ◽  
Simulated Wastewater

The performance of activated carbon (AC) adsorption process for the treatment of a simulated wastewater of fuchsin basic dye was investigated. The experiment revealed that under the optimum adsorption conditions (initial concentration of wastewater 250 mg L-1of dye, temperature 25 °C and AC dosage 4 g L-1), the color removal efficiency was 98% after 360 min of adsorption. As for the further use of AC, the saturated AC was regenerated by heated 20 min at 600 °C in the atmosphere of N2. Efficiency of regeneration was 99% and the regeneration loss was less than 5%. It indicated that AC was effective in the decolorization of dye wastewater.

scholarly journals Color removal efficiency of rice husk biochar modified with magnetized iron oxides and nano zero valent iron for decolorization of dyeing wastewater

2020 ◽  
Vol 3 (2) ◽  
pp. 105-114
Author(s):  
Bao-Son Trinh ◽  
Pham Thi Kieu Chinh ◽  
Ha Đoan Tram
Keyword(s):  
Iron Oxides ◽  
Removal Efficiency ◽  
Rice Husk ◽  
Reactive Dyes ◽  
Zero Valent Iron ◽  
Color Removal ◽  
Dyeing Wastewater ◽  
Nano Zero Valent Iron ◽  
Initial Color ◽  
Rice Husk Biochar

Rice husk biochar, a rich-carbon material, can be modified with other reactive elements to improve its original properties for organic-contaminant removal efficiency. In this study, rice husk was heated to 600 oC without air in a closed-furnace for producing the rice husk biochar (BC600). BC600 was then magnetized for making an intermediate magnetized rice husk biochar (BC600-mag). Finally, nano zero valent iron (nZVI) was synthesized on BC600-mag for producing magnetized biochar impregnated nZVI (BC600-mag-nZVI). Batch experiments were conducted to investigate color removal efficiency of BC600-mag-nZVI for the reactive dyes yellow (RY145), red (RR195) and blue (RB19) from dyeing solutions with the initial color concentrations of approximately 400 Pt-Co. Results showed that, for RY145 and RR195, the optimum color removal efficiency (ɳopt) achieved the values of 95 and 93% at doses of 0.50 and 1.50 kg BC600-mag-nZVI/m3 dyeing solution, according to the treated color decreased to 21 and 30 Pt-Co, respectively, which are lower than the allowable discharged standard of column A (≤ 50 Pt-Co) of QCVN 40:2011/BTNMT, while for RB19, the ɳopt achieved the values of 63 % at dose of 8.00 kg BC600-mag-nZVI/m3 dyeing solution, according to the treated color decreased to 147 Pt-Co which is lower than the allowable discharged standard of column B (≤ 150 Pt-Co) of QCVN 40:2011/BTNMT. In addition, with increasing dose of the modified biochars, the color removal efficiency increased accordingly, achieving almost 100% for RY145 and RR195 and over 70% for RB19. It is concluded that the magnetic-nZVI rice husk biochars effectively removed the reactive dyes. In the other hand, the impregnation of nZVI particles on the biochar backbone spatially separates the particles, prevents their aggregation and therefore enhances their reactivity This study therefore proposes a new application of rice husk biochar modified with magnetized iron oxides and zero valent iron decolorization of dyeing wastewater.

scholarly journals Rice Husk Biochars Modified with Magnetized Iron Oxides and Nano Zero Valent Iron for Decolorization of Dyeing Wastewater

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 660 ◽  
Author(s):  
Bao-Son Trinh ◽  
Phung T. K. Le ◽  
David Werner ◽  
Nguyen H. Phuong ◽  
Tran Le Luu
Keyword(s):  
Removal Efficiency ◽  
Rice Husk ◽  
Low Cost ◽  
Reactive Dyes ◽  
Zero Valent Iron ◽  
Color Removal ◽  
Dyeing Wastewater ◽  
Decolorization Efficiency ◽  
Nano Zero Valent Iron ◽  
Rich Material

This study investigated if biochar, a low-cost carbon-rich material, can be modified with reactive materials for decolorization of dyeing wastewater. Two types of rice husk biochars were produced by using different processes of gasification and pyrolysis in limited air condition. The biochars were first magnetized and then modified with nano-scale zero-valent iron (nZVI) to achieve the final products of magnetic-nZVI biochars. Batch experiments were conducted to investigate the efficiency of the modified biochars for reducing color of the reactive dyes yellow (RY145), red (RR195), and blue (RB19) from dyeing solutions. Results showed that color removal efficiency of the modified biochars was significantly enhanced, achieving the values of 100% for RY145 and RR195 and ≥65% for RB19, while the effectiveness of the original biochar was significantly lower. In addition, with increasing dose of the modified biochars, the color removal efficiency increased accordingly. In contrast, when the dose of nZVI was increased beyond a certain value then its color removal efficiency decreased accordingly. It is reported that the magnetic-nZVI rice husk biochars effectively removed the reactive dyes. The impregnation of nZVI particles on the biochar surface spatially separates the nZVI particles, prevents its aggregation and therefore enhances the decolorization efficiency.

Color Removal from Dyeing Wastewater by the Polymer of Epichlorohydrin-Ethylenediamine

2013 ◽  
Vol 750-752 ◽  
pp. 1448-1451 ◽  
Author(s):  
Cui Zhen Sun ◽  
Xiao Rui Zhang ◽  
Zhi Bin Zhang ◽  
Yan Hao Zhang
Keyword(s):  
Removal Efficiency ◽  
Ferric Chloride ◽  
Reactive Dyes ◽  
Color Removal ◽  
Dyeing Wastewater ◽  
Neutralization Ability ◽  
Flocculation Process ◽  
Performance And Mechanism

A new polymer of epichlorohydrin-ethylenediamine was obtained by suspension polycondensation of ethylenediamine with epichlorohydrin. The color removal performance and mechanism of the polymer in the treatment of synthetic reactive dyes wastewater was investigated, and in comparison with polymeric aluminum ferric chloride (PAFC) and polydimethyldiallylammonium chloride (PDMDAAC). The results showed that epichlorohydrin-ethylenediamine achieved higher color removal efficiency, and its adsorption-bridging and electric neutralization ability playedimportant roles in the flocculation process.

Determination of the lattice translation across {110} APBs in GaAs

1988 ◽  
Vol 46 ◽  
pp. 600-601
Author(s):  
D.R. Rasmussen ◽  
N.-H. Cho ◽  
C.B. Carter
Keyword(s):  
Grain Boundaries ◽  
Lower Energy ◽  
Antiphase Boundary ◽  
The Other ◽  
Boundary Structure ◽  
Interface Plane ◽  
Inversion Symmetry ◽  
High Angle ◽  
Equilibrium Distance

Domains in GaAs can exist which are related to one another by the inversion symmetry, i.e., the sites of gallium and arsenic in one domain are interchanged in the other domain. The boundary between these two different domains is known as an antiphase boundary [1], In the terminology used to describe grain boundaries, the grains on either side of this boundary can be regarded as being Σ=1-related. For the {110} interface plane, in particular, there are equal numbers of GaGa and As-As anti-site bonds across the interface. The equilibrium distance between two atoms of the same kind crossing the boundary is expected to be different from the length of normal GaAs bonds in the bulk. Therefore, the relative position of each grain on either side of an APB may be translated such that the boundary can have a lower energy situation. This translation does not affect the perfect Σ=1 coincidence site relationship. Such a lattice translation is expected for all high-angle grain boundaries as a way of relaxation of the boundary structure.

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