Equilibrium analysis copper ions sorption on zeolite from various heavy metal sources : master thesis

Ispitana je sorpcija bakrovih iona na sintetskom zeolitu NaX u ovisnosti o različitim početnim koncentracijama otopina bakrovog(II) nitrata i bakrovog(II) klorida. Eksperiment je proveden u šaržnim reaktorima pri stalnoj temperaturi od 306 K, brzini miješanja od 200 okr min-1, u trajanju od 3 h. Uočeno je da kod sorpcije bakrovih iona iz otopine bakrovog(II) nitrata kapacitet sorpcije naglo raste s porastom početne koncentracije bakrovih iona do koncentracije od 22,909 mmol dm-3 te se neznatno mijenja daljnjim povećanjem početne koncentracije. Kod sorpcije bakrovih iona iz otopine bakrovog(II) klorida kapacitet sorpcije cijelo vrijeme raste s porastom početne koncentracije bakrovih iona te dostiže svoj maksimalni kapacitet sorpcije pri najvišoj odabranoj koncentraciji. Analizom dobivenih rezultata za obje otopine uočava se neprestani pad učinka sorpcije bakrovih iona na zeolitu s porastom početne koncentracije, a primijećeno je da je i učinak sorpcije bakrovih iona iz otopine bakrovog(II) klorida uvijek viši od učinka sorpcije bakrovih iona iz otopine bakrovog(II) nitrata za sve početne koncentracije osim za najnižu odabranu početnu koncentraciju. Dobiveni eksperimentalni podatci su testirani različitim sorpcijskim modelima. Kako bi procjena kvalitete slaganja modela izotermi s eksperimentalnim podatcima bila što preciznija uzeto je u obzir i slaganje izračunatih ravnotežnih kapaciteta sorpcije bakrovih iona s maksimalnim eksperimentalnim kapacitetom sorpcije bakrovih iona, kao i vrijednost statističkih parametara izračunatih za RMSE i χ2. Uzimajući u obzir sve navedeno može se zaključiti da najbolje slaganje s eksperimentalnim podatcima pokazuje Tothova izoterma kod sorpcije bakrovih iona iz otopine bakrovog(II) nitrata, dok je kod sorpcije bakrovih iona iz otopine bakrovog(II) klorida nabolje slaganje postignuto primjenom Langmuirove izoterme.Sorption of copper ions on a synthetic zeolite NaX was examined depending on different initial concentrations of copper (II) nitrate and copper (II) chloride solutions. The experiment was conducted in batch reactors at a constant temperature of 306 K, stirring speed of 200 rpm, for 3 hours. It was observed that for the sorption of copper ions from a solution of copper (II) nitrate, the sorption capacity increases rapidly with an increase in the initial concentration of copper ions until the concentration of 22.909 mmol dm-3 and slightly changes at the higher concentrations. In the case of copper ions sorption from a solution of copper (II) chloride, the sorption capacity increases all the time with an increase in the initial concentration of copper ions and reaches its maximum sorption capacity at the highest selected concentration. The analysis of the obtained results for both solutions shows a constant decrease in the sorption efficiency of copper ions on the zeolite with an increase in the initial concentration. It was also observed that the sorption efficiency of copper ions from copper (II) chloride solution is consistently higher than the sorption efficiency of copper ions from copper (II) nitrate solution for all initial concentrations except for the lowest selected initial concentration. To make the assessment as precise as possible the maximum experimental capacity of sorption of copper ions and value of the statistical parameters calculated, RMSE and χ2 were also taken into account. Taking everything into account all of the above, it can be concluded that the best agreement with the experimental data is shown by the Toth isotherm for the sorption of copper ions from a solution of copper (II) nitrate, while the best agreement with the sorption of copper ions from a solution of copper (II) chloride is achieved by using the Langmuir isotherm