Odstranjevanje težkih kovin iz kontaminirane zemlje

diplomsko delo visokošolskega strokovnega študijskega programa I. stopnje

Tilen Peček (Author), Darko Goričanec (Mentor), Danijela Doberšek (Co-mentor)

Abstract

Namen diplomske naloge je bilo s pomočjo literature preučiti vrste postopkov odstranjevanja težkih kovin iz onesnažene zemlje in možnost njihove ponovne uporabe v kmetijstvu. Odločil sem se za postopek pranja sedimenta in blata, ki smo ga pridobili iz dveh čistilnih naprav. Z eksperimentom sem poskušal določiti najprimernejši čas pranja vzorca v kelatnem sredstvu, ki je bil v našem primeru EDTA. V teoretičnem delu so opisani najpogostejši vzroki kontaminacije in posledice degradacij tal s težkimi kovinami. Prav tako so povzete lastnosti naslednjih elementov: svinec, kadmij, cink, mangan, železo, nikelj, živo srebro, arzen, kositer. Predstavljenih pa je tudi vrsto različnih postopkov oz. načinov čiščenja prsti. Eksperimentalni del sem izvedel v laboratoriju, kjer sem na začetku pripravil načrt izvedbe eksperimenta, povezanega z določevanjem količin posameznih težkih kovin v vzorcu zemlje pred in po čiščenju z EDTA. Sledil je postopek priprave vzorca, vse od vzorčenja, mletja, sejanja in sušenja. Za analizo sem imel tri različne vzorce, in sicer: sediment Drave, blato iz industrije težkih odpadkov in mulj iz čistilne naprave. Nato sem začel s postopkom pranja, tako da sem na vzorce nalili ligand EDTA in pričel z mešanjem. Po končani metodi je sledila filtracija in sušenje očiščene zemlje. Izbral sem metodo razklopa z zlatotopko in s hitrimi testi dobili vednosti težkih kovin v zemljini. Elementi kroma, železa in cinka so imeli največje vrednosti koncentracij, ki pa se je skozi daljšanje časa pranja zmanjševala. Opazil sem tudi, da je najprimernejši čas pranja pri šestih urah.

Keywords

onesnaženost tal;težke kovine;postopek pranja;razklop;degradacija;diplomske naloge;

Data

Language:	Slovenian
Year of publishing:	2019
Typology:	2.11 - Undergraduate Thesis
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher:	[T. Peček]
UDC:	66.069.1:628.516(043.2)
COBISS:	22674966
Views:	1187
Downloads:	220
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Removal of heavy metals from contaminated soil
Secondary abstract:	The aim of this paper is to study the types of heavy metal removal processes from contaminated soil and the possibility of their re-use in agriculture. After theoretical exploration of that topic I practically researched the sediments and sludge washing process. We obtained samples from two treatment plants. With the experiment, I tried to determine the most appropriate washing time of the sample in the chelating agent, which in our case was EDTA. In theoretical part I described the most common causes of contamination and the consequences of soil degradation by heavy metals. The properties of the following elements are also explained: lead, cadmium, zinc, manganese, iron, nickel, mercury, arsenic and tin. I also explained a number of different procedures or ways of cleaning the soil. The experimental part was carried out in the laboratory. I initially prepared a plan for carrying out an experiment, which includes defining the amount of a specific heavy metal in the soil sample before and after EDTA washing. A sample preparation process followed, everything from sampling, grinding, sieving and drying. I had three different samples to analyze: Drava sediment, heavy waste sludge, and sewage sludge. I then started the washing process by pouring EDTA ligand onto the samples and started mixing. This was followed by filtration and drying of the purified soil. I chose the aqua regia method of decomposition and obtained the amount of heavy metals in the soil by rapid tests. The elements of chromium, iron and zinc had the highest values of concentrations, which decreased with time of washing. I also discover that the most appropriate time of washing is 6 hours.
Secondary keywords:	soil pollution;heavy metals;washing process;EDTA;aqua regia;degradation;
Type (COBISS):	Bachelor thesis/paper
Thesis comment:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages:	VIII, 39 str.
ID:	11214926