**1. Introduction**

There are more than 3000 different dyes available and half of them belong to the azo dyes compounds class [1]. Azo dyes are the most frequently used dyes in textile industry and are characterized by the presence of one or more azo linkages (─N═N─), usually in number of one or four, linked to phenyl and naphthyl radicals, which are usually replaced with some combinations of functional groups including: amino (─NH2 ), chlorine (─Cl), hydroxyl (─OH), methyl (─CH<sup>3</sup> ), nitro (─NO2 ), sulfonic acid (─SO<sup>3</sup> H), and sodium salts (─SO<sup>3</sup> Na) [2–4]. These compounds can lead to significant ecological problems because of the creation

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

of carcinogenic or mutagenic compounds [5–7]. Several azo dyes have been described to lead human bladder cancer, splenic sarcomas, and hepatocarcinoma, because azo dye reduction in the intestinal tract release aromatic amines which are absorbed by the intestine and excreted in the urine [8]. The acute toxicity of azo dyes, with respect to the criteria of the European Union for the sorting of unsafe substances, is low and the values of LD50 are 250–2000 mg/kg body weight [9, 10].

LS-Fe<sup>3</sup> O4

**2.1. Materials**

, and LS-ZnO/Fe<sup>3</sup>

**2. Materials and methods**

**2.2. Green synthesis of Fe3**

Direct Blue 15 (CAS no: 2429-74-5), FeCl2

mists. All solutions were made in deionized water.

**O4**

*2.2.1. Collection of plant sample and preparation of plants extract*

(pH 6.0) and was incubated at 4°C for further analysis [23].

water instead of enzyme in the reaction mixture.

 *and ZnO nanoparticles*

*O4*

*2.2.3. Peroxidase enzyme activity test*

*2.2.4. Synthesis of Fe<sup>3</sup>*

added in sample FeCl2

O4

isotherms and kinetics and thermodynamics of these membrane forms were investigated.

, ZnCI2

 **and ZnO nanoparticles**

*2.2.2. Partial purification of the peroxidase enzyme with ammonium sulfate precipitation*

Sigma-Aldrich. Euphorbia (*Euphorbia amygdaloides*) was collected from near the town of Hasankale of Erzurum. Also, LS which is fruit of *Luffa cylindrica* was obtained from a local point of spices sale in Erzurum, Turkey, and they were identified with the helping of taxono-

Plants (*Euphorbia amygdaloides*) were collected from Hasankale town of Erzurum city. They were washed with distilled water several times for cleaning dust and soil on plants. Then, plants were cut into small pieces. Small pieces (50 g) were thoroughly shattered to form a homogeneous mixture in blender using 250 mL, 10 mM sodium phosphate buffer (pH 6.0). Then, it was centrifuged at 5000×*g* for 10 min and the supernatant was used for enzyme purification [23].

Prepared Euphorbia (*Euphorbia amygdaloides*) plant homogenate was saturated from 60 to 80% with ammonium sulfate, then the peroxidase enzyme was precipitated by centrifuged at 8000×*g*, 10 min. Obtained precipitate was dissolved at 10 mM sodium phosphate buffer

Determination of peroxidase activity was made by substrate of 1 mM 2,2′-azino-bis(3-ethylbenzthiazoline-sulfonic acid) diammonium salt (ABST) prepared in 0.1 M phosphate buffer at pH 6. For this purpose, 2.8 mL ABST was transferred to a test tube, and then the reaction

tion into the test tube. The change in absorbance was monitored at 412 nm using UV–Visible spectrophotometer at 1 min intervals for 3 min. Blank test tube was prepared using distilled

100 μL of purified peroxidase enzyme from Euphorbia (*Euphorbia amygdaloides*) plant were

of solution (2.9 mL, 10 mM) and incubated in a closed space for 4 h.

mixture was formed by the addition 100 μL of 80% enzyme and 100 μL of 3.2 mM H2

) were characterized by SEM, FT-IR, and XRD. Also, adsorption

The Investigation of Removing Direct Blue 15 Dye from Wastewater Using Magnetic *Luffa sponge* NPs

, and other chemicals were purchased from

http://dx.doi.org/10.5772/intechopen.73216

209

O2 solu-

The textile dyes can be removed by using physical, chemical, and biological methods [11]. Nevertheless, most of these methods, which simply accumulate or concentrate the dyes, and trigger secondary contamination, resulted in the extreme usage of chemical materials [11, 12].

Because of nanoparticles' features arising from size effect, nanotechnology has emerged in many scientific and industrial fields [13, 14]. It involves studies of measurement, modeling, and manipulation of substance in nanoscale. Nanoremediation is economic and has improved overall efficiency of fragmentation process. Potential catalytic activity of Au, Ag, Pd, Mg, Cu, Zn, and Fe nanoparticles have been reported for degradation of some aqueous cationic and anionic dyes [14–18]. Researchers studied degradation of Methyl Orange, Sunset Yellow, Acid Blue A azo dyes using zero valent iron nanoparticles (NZVI) with diameters between 20 and 110 nm. Methyl Orange, Sunset Yellow, Acid Red A were removed using solution prepared with 2 g NZVI rate of 79.9, 98.9, and 98.8, respectively [19].

However, nanoparticles are left in the ecosystem after their use in the removal of environmental contaminants. Thus, nanoparticles immobilized on a support material are to the fore for environmental remediation [20, 21]. LS is eco-friendly, cost effective, easy to use matrix material successfully used as a biotechnological tool for variety of systems, purposes and applications. LS immobilized cell systems have efficiently studied toward biofilm development for remediation of domestic and industrial wastewater containing toxic metal, paint, chlorinated compounds [22, 32].

In this study, ZnO and Fe<sup>3</sup> O4 nanoparticles were obtained by catalyzing using purified peroxidase enzymes from *Euphorbia amygdaloides* with green synthesis method. Membrane forms have been created by immobilizing the obtained nanoparticles on LS support material. Carcinogenic DB15 azo dye was used to evaluate effectiveness of ones to remove dye (molecular structure of DB15 shown in **Figure 1**). Optimum contact time, pH, temperature, and concentration of dye were analyzed using UV-visible spectrometry. The resulting adsorbents (LS-pure, LS-ZnO,

**Figure 1.** Molecular structure of DB15.

LS-Fe<sup>3</sup> O4 , and LS-ZnO/Fe<sup>3</sup> O4 ) were characterized by SEM, FT-IR, and XRD. Also, adsorption isotherms and kinetics and thermodynamics of these membrane forms were investigated.
