In this study, the adsorption capacity of toxic and recalcitrant organic pollutant(s) Remazol Brilliant Blue R (RBBR) onto the invader Xanthium İtalicum (XI) plant was assessed using the Response Surface Method (RSM). The adsorp-tion behavior of RBBR was determined by the spectrophotometric method, FTIR and SEM analysis were used to characterize XI, Brunauer, the Emmett and Teller (BET) analysis was accomplished to find the surface area of the ad-sorbent. The experiment procedures were planned by the Central Composite Design (CCD) whereby a model was built to examine the effects of the different parameters and the possible interaction between them. The correlation factor (R2) for the developed model was 0.985, suggesting that the model could achieve 98.5% of RBBR removal through an adsorption process. The desirability of 0.992 can be attained using the identified optimum conditions: XI = 3g, pH = 9, Time = 84min, RBBR = 50ppm. Under these conditions, the adsorption capacity reached 1.59 mg.g-1, and the removal percentage reached 95%. Freundlich isotherm had the best-fitted values with R2 of 0.999. Furthermore, the adsorption of RBBR onto XI was found to be pseudo-second-order kinetic with R2=0.999. Also, the recovery of RBBR from XI was studied through desorption experiments in presents of 0.5M NaOH. The recovery percentage after 120 min reached 47%. The maximum recovery percentage reached 73% at 24h.

İstilacı bitkiler, tarım ürünlerinin gelişimini engelleyerek ürün verimini azaltmaktadır. Bu çalışmada, sentetik bir boya olan Malachite Green (MG)'nin sulu çözeltiden uzaklaştırılmasında tarımsal atık olan istilacı Centaurea Solstitialis (CS) bitkisi adsorban olarak kullanılmıştır. Adsorbent - adsorbate ilişkisi, spektrofotometrik yöntem ve Fourier dönüşüm infrared (FTIR) ile incelenmiştir. Yüzey morfolojisi taramalı elektron mikroskobu (SEM) ile belirlenmiştir. CS yüzey alanı Brunauer, Emmett ve Teller (BET) analizi ile ölçülmüştür. Deney tasarımı ve modellemesinde RSM kullanılmış ve korelasyon faktörü 0,984 olarak bulunmuştur. Optimum çalışma koşulu olan 312.5 mg.L -1 MG içeren çözeltiye (pH=7.5) 0.325 g CS (30 mesh) koyularak 150 rpm’de 75 dakika çalkalanmıştır. Çalışmada CS tanecik boyutu 30 mesh ve çalkalama hızı 150 rpm sabit tutulmuştur. Optimum çalışma koşullarında CS’nin maksimum adsorpsiyon kapasitesi 90.816 mg.g -1 bulunmuştur. Sonuçlar Langmuir, Freundlich, Temkin ve Dubinin-Radushkevich (D-R) izotermleri ile değerlendirilmiştir. Sonuç olarak adsorpsiyon işleminin Temkin izotermine (0,997 R 2 ) uyan yalancı ikinci dereceden (R 2 = 0.9982) bir kinetik reaksiyon olduğu bulunmuştur. İntrapartikül difüzyon modeli, sırasıyla sınır difüzyon tabakası ve partikül içi difüzyon etkilerini göstermiştir. Adsorpsiyonun -4,47 KJ.mol -1 Gibbs serbest enerjisi ile endotermik olduğu bulunmuştur. Desorpsiyon çalışmasında maksimum %2.16’lık bir verim elde edilmiştir. Bu sonuç CS üzerine adsorbe olan MG’nin tekrar suya karışma ihtimalinin düşük olduğunu göstermektedir. Daha sonra kolon çalışmalarına geçilmiştir. Kolonun verimliliği, 40. dakikada % 99.5'e ulaşmış ve bundan sonra sabit kalmıştır. Sonuç olarak, CS’nin, sulu çözeltiden MG gideriminde etkili bir adsorbent olduğu bulunmuştur.

In this study, calcium alginate (Ca-Alg) beads were mixed with leonardite powder to prepare leonardite-embedded calcium alginate (Leo-Ca-Alg) beads. The prepared Leo-Ca-Alg beads were utilized for the adsorption of the Safranin-O dye. Leo-Ca-Alg beads were characterized by X-ray diffraction, Fourier transform infrared, and scanning electron microscopy before and after the adsorption process. The effects of pH, adsorbent dose, initial dye concentration, and contact time on the adsorption of Safranin-O dye onto Leo-Ca-Alg beads were investigated. The optimal condition was achieved at a pH value of 8.0, an adsorbent amount of 20 g/L, an initial concentration of 10 mg/L, and a contact time of 120 min. Under optimum conditions, 98.91% dye removal efficiency was obtained. Besides, the isotherm, kinetic, and thermodynamic were studied for the adsorption process. Accordingly, the removal of Safranin-O dye by the Leo-Ca-Alg adsorbent can be defined by the Freundlich model and described by the Elovich model and the second-order kinetic model at concentrations of 10 and 20–30 mg/L, respectively. The Safranin-O removal by Leo-Ca-Alg was feasible and naturally spontaneous. In reuse cycle studies, it was tried up to 10 reuses and decreased from 98.91 to 83.01% in the 10th use.