**4. Conclusion**

**Figure 10.** Thermodynamic kinetics graph for adsorption of DB15 azo dye with formed membrane forms.

ΔG° values decreased as the temperature increases in adsorption of DB15 azo dye with all membrane forms. This shows an increasing tendency in the feasibility and spontaneity of DB15 azo dye adsorption. The fact that ΔG° has negative values means that the adsorption of DB15 azo dye is spontaneously. The negative values of ΔH° confirm the exothermic structure of the adsorption process. Therefore, the adsorption of DB15 azo dye with membranes formed by the use of

**Table 5.** First- and second-order adsorption rate constants in DB15 azo dye removal.

**First order Second order**

**R2 k2**

 **(g/mg min)**

**qecal (mg/g)** **R2**

**DB15**

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

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

O4

**Adsorbent Initial dye** 

222 Iron Ores and Iron Oxide Materials

**conc.**

**qeexp (mg/g)**

**k1**

 **(L/min) qecal**

LS 10 8.8 0.034 0.845 0.9954 5.77 × 10−4 16.53 0.9751

LS*-*ZnO NPs 10 9.1 0.053 0.809 0.9974 2.63 × 10−3 12.03 0.9702

NPs 10 8.6 0.055 0.949 0.925 2.03 × 10−3 13.14 0.9912

**(mg/g)**

25 12.6 0.030 0.978 0.9977 2.27 × 10−3 20.70 0.9955 50 33.6 0.0.28 1.296 0.9873 6.8 × 10−5 96.15 0.6882

25 17.1 0.038 1.071 0.9986 1.03 × 10−3 26.46 0.9923 50 49.65 0.049 1.395 0.9744 8.78 × 10−5 95.24 0.9547

25 22.7 0.049 1.113 0.9983 1.45 × 10−3 27.25 0.991 50 44.3 0.054 1.414 0.9603 1.48 × 10−4 76.33 0.9654

25 24.0 0.039 1.075 0.9494 1.23 × 10−3 29.94 0.9537 50 48.6 0.054 1.400 0.9715 2.54 × 10−4 67.57 0.9876

NPs 10 8.9 0.047 0.839 0.9821 2.83 × 10−3 12.76 0.9971

In this study on remediation, the possibilities offered by the environment are evaluated. ZnO and Fe<sup>3</sup> O4 NPs were produced by green synthesis with catalyzed peroxidase enzyme partially purified from *Euphorbia amygdaloides* plant. In this phase of the study, a new plant source was presented to literature for the green synthesis of nanoparticles. It has also been shown that produced nanoparticles may play an active role in dye adsorption. The synthesis of this plant with other nanoparticles will be further studied.

LS is a natural plant that can grow in many countries, can be used for many purposes, and has recently undergone a lot of research. In this study, nanoparticles were immobilized successfully on this material. In this way, it is aimed to prevent the nanoparticles accumulation in the environment and the creation of a separate pollution. Adsorption of DB15, a carcinogenic azo dye, was studied with nanoparticle-loaded membrane forms. Optimization, characterization, kinetic, thermodynamic studies demonstrated effectiveness of the membrane forms used in dye adsorption. For this reason, we can easily say that this work will be a source for commercialized membrane systems in the future.
