Adsorpcija izbranih težkih kovin na odpadno glivno biomaso

Rozman, Ula (author), Kalčikova, Gabriela (mentor)

Težke kovine uvrščamo med nevarna onesnaževala, ki se v tleh kopičijo zaradi industrijskih dejavnosti kot so galvanizacija, metalurgija, rudarstvo in proizvodnja kemikalij. Iz tal pa s spiranjem zlahka vstopajo tudi v vodni ekosistem. Za odstranjevanje težkih kovin iz vod se običajno uporabljajo različne fizikalno-kemijske metode, med katerimi velja za najbolj učinkovito adsorpcija. Učinkovitost je odvisna od kinetičnih parametrov in kapacitete adsorbenta. V zadnjem času se raziskuje predvsem možnost uporabe različnih bioloških materialov, med katerimi so še posebno zanimivi odpadni biološki materiali, saj so učinkoviti in ne prinašajo dodatnih stroškov. V okviru magistrskega dela smo raziskovali možnost uporabe odpadne glivne biomase za adsorpcijo svinca in kadmija. Uporabljena odpadna glivna biomasa je bila podgobje glive Ganoderma lucidum, skupaj s substratom na katerem je gliva gojena. Pri proizvodnji prehranskih dodatkov je tega odpadka veliko v primerjavi s trosnjaki glive, ki jih uporabijo za proizvodnjo. Zato je iskanje možnosti uporabe tega odpadka zelo zaželeno in v skladu s sodobnimi trendi zmanjševanja odpadkov v industriji in vpeljavo krožnega gospodarstva. V prvem delu smo glede na literaturo odpadno glivno biomaso obdelali s tremi različnimi kemikalijami (0,5 M NaOH, 10 vol% H2O2 in 0,5 M NaCl) in z njo izvedli poskuse adsorpcije svinca in kadmija, ter določili učinkovitost in kinetiko adsorpcije. Ugotovili smo, da je tako neobdelana, kot tudi obdelana odpadna glivna biomasa učinkovit adsorbent, saj se je večino kovin odstranilo že v prvih petih minutah poskusa. V nadaljevanju smo za neobdelano odpadno glivno biomaso in obdelano z 0,5 M NaCl izvedli še poskuse adsorpcije pri različnih koncentracijah odpadne glivne biomase, ter na koncu določili Freundlichovo adsorpcijsko izotermo. Ker pa je to popolnoma nepoznan adsorbent, smo material preučili z optičnim in vrstičnim elektronskim mikroskopom, kjer smo si podrobneje ogledali obliko delcev in površino. S pomočjo BET metode smo določili specifično površino materiala, ki je bila relativno nizka. Z lasersko difrakcijo smo določili numerično porazdelitev velikosti delcev. Raziskana odpadna glivna biomasa predstavlja velik potencial za adsorpcijo težkih kovin iz odpadnih vod. Poleg tega da zelo hitro in učinkovito odstranjuje težke kovine že pri nizkih koncentracijah, je kot odpadek cenovno ugodna in ni nevarna za okolje.

• Language: Slovenian
• Keywords: adsorpcija, biosorpcija, Ganoderma lucidum, težke kovine
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2019
• PID: 20.500.12556/RUL-109330
• COBISS.SI-ID: 1538323651
• Publication date in RUL: 30.08.2019

Secondary language

• Language: English
• Title: Heavy metal adsorption on waste fungal biomass

Abstract

Heavy metals are known to be dangerous pollutants. They enter the environment through industrial activities such as galvanization, metallurgy, mining, chemical production and due to runoff they can easily enter aquatic ecosystems. Various treatment technologies have been applied for the removal of heavy metals, among them adsorption is considered to be the most effective. The efficiency depends on the kinetic parameters and the adsorbent capacity. In the last decade, various biological materials have been investigated as adsorbents, particularly interesting is the use of waste biological materials, due to low-cost and efficiency. In this research, the possibility of using waste fungal biomass as adsorbent for lead and cadmium has been investigated. Waste fungal biomass was obtained after production of Ganoderma lucidum fruiting bodies and is made of residues of fungi and substrate on which fungi was cultivated. A high amount of such waste is generated and therefore using this waste is highly desirable and in line with the modern trends of waste reduction in industry and the circular economy. Waste fungal biomass was pretreated with three different chemicals (0.5 M NaOH, 10 vol% H2O2 and 0.5 M NaCl). The removal efficiency and adsorption kinetics were determined for untreated and pretreated waste fungal biomass. With all four waste fungal biomass the removal efficiency for lead and cadmium was high and almost all metal ions were adsorbed in the first five minutes. For untreated waste fungal biomass and for pretreated with 0.5 M NaCl adsorption experiments were performed with different concentrations of waste fungal biomass and later Freundlich adsorption isotherm was determined. As characteristics of waste fungal biomass are unknown, some morphological properties were determined using optical and scanning electron microscope. Specific surface area was calculated using BET method and was quite low. Particle size of the number distribution was determined with laser diffraction. The investigated waste fungal biomass represents a great potential for adsorption of heavy metals from wastewaters or contaminated surface waters, due to the cost-effectiveness and the possibility to adsorb metals at low concentrations.

• Keywords: adsorption, biosorption, Ganoderma lucidum, heavy metals