ANALYSIS OF ELECTROCOAGULATION PROCESS EFFICIENCY OF COMPOST LEACHATE WITH THE FIRST ORDER KINETIC MODEL

Large quantities of leachate are generated from the water release during the decomposition of the biodegradable waste. The composition of compost leachate is very complex and its treatment is necessary before releasing into the environment. The possibilities of treating compost leachate by electrocoagulation have been extensively studied. The scope of this work was to investigate applicability of the first order kinetic model for degradation of metal and organic compounds from compost leachate by electrocoagulation process. Experimental results showed 75 % removal efficiency of Cu2+ and 65 % of Zn2+, while chemical oxygen demand was reduced by 36 %. According to obtained kinetic parameters, simulation of metal removal efficiency was performed in batch reactor. This way optimal electrocoagulation time which is needed for 95 % efficiency of metal removal was determined at 120th min for Zn2+ and 102nd min for Cu2+

Adsorption and antibacterial activity of soluble and precipitated chitosan on cellulose viscose fibers

The aim and novelty of this work was to compare the adsorption of totally-soluble chitosan (acidic solution) against the adsorption of precipitated chitosan, onto cellulose fibers. The influences of both these chitosan-adsorption procedures on a final amino groupćs content in functionalized cellulose fibers were studied, using potentiometric titration and the conventional spectrophotometric C.I. Acid Orange 7 method. Surface modification and adsorption of chitosan were, in addition, monitored by determining XPS spectra. The antimicrobial activities of both chitosan- functionalised cellulose fibers were examined, in regard to pathogen bacteria and fungus

Antimicrobial efficiency of functionalized cellulose fibres as potential medical textiles

This chapter presents an overview of methods for cellulose fibres functionalization in order to introduce antimicrobial activity. In view the need for ecologically friendly textiles antimicrobial finishing is introduced, together with some strategies for the functionalization of fibres using biodegradable polysaccharides such as the use of chitosan. Additionally,the methods used for the microbiological testing of these fibres are discussed and the current disadvantages of these methods indicated. Moreover, a new strategy for a reliable methodology regarding the antimicrobial testing of oriented fibre-based polymers such as cellulose is discussed, which could also be useful within several other polymer industrial fields

TEMPO oksidacija u funkciji poboljsanja antibakterijskih svojstava viskozne tkanine funkcionalizovane nanočesticama na bazi hitozana

TEMPO oxidation of viscose fabric was used as a pretreatment 10 introduce carboxyl and aldehyde groups for irreversible binding of chilosan and to improve antibacterial activity and washing durability of viscose fabrics functionalized with chitosan nanoparticles withour (NCS) and with emt edded zine (NCS+ Zn). Carboxyl and aldehyde group content, electrokinetic properties, elemental analysis, inductively coupled plasma optical emission spectrometry and antibacterial testing were used to caluare the influence of TEMPO axidation on subseguent NCS and NCS+Zn binding and antibacterial properties of chitosan functionalized viscose fabrics. Anvibacterial activity of NCS and NC$+Zn functionalized viscose fabrics was preserved after multiple wasting

Ružička days : International conference 16th Ružička Days “Today Science – Tomorrow Industry” : Proceedings

Proceedings contains articles presented at Conference divided into sections: open lecture (1), chemical analysis and synthesis (3), chemical and biochemical engineering (8), food technology and biotechnology (8), medical chemistry and pharmacy (3), environmental protection (11) and meeting of young chemists (2)

Biomass-Derived Plant Extracts in Macromolecular Chitosan Matrices as a Green Coating for PLA Films

Due to the growing problem of food and packaging waste, environmental awareness, and customer requirements for food safety, there is a great need for the development of innovative and functional packaging. Among these developments, the concept of active packaging is at the forefront. The shortcoming in this area is that there is still a lack of multifunctional concepts, as well as green approaches. Therefore, this work focuses on the development of active chemical substances of natural origin applied as a coating on polylactic acid (PLA) films. Biopolymer chitosan and plant extracts rich in phenolic compounds (blackberry leaves—Rubus fruticosus, needles of prickly juniper—Juniperus oxycedrus) obtained from plant biomass from Southeastern Europe were selected in this work. In order to increase the effectiveness of individual substances and to introduce multifunctionality, they were combined in the form of different colloidal structural formulations. The plant extracts were embedded in chitosan biopolymer particles and dispersed in a macromolecular chitosan solution. In addition, a two-layer coating, the first of a macromolecular chitosan solution, and the second of a dispersion of the embedded extracts in chitosan particles, was applied to the PLA films as a novel approach. The success of the coatings was monitored by X-ray photoelectron spectroscopy (XPS) and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), and the wettability was evaluated by contact angle measurements. Scanning electron microscopy SEM tracked the morphology and homogeneity of the coating. Antioxidation was studied by DPPH and ABTS spectrophotometric tests, and microbiological analysis of the films was performed according to the ISO 22196 Standard. Desorption of the coating from the PLA was monitored by reducing the elemental composition of the films themselves. The successful functionalization of PLA was demonstrated, while the XPS and ATR-FTIR analyses clearly showed the peaks of elemental composition of the extracts and chitosan on the PLA surface. Moreover, in all cases, the contact angle of the bilayer coatings decreased by more than 35–60% and contributed to the anti-fogging properties. The desorption experiments, due to decrease in the concentration of the specific typical element (nitrogen), indicated some migration of substances from the PLA’s surface. The newly developed films also exhibited antioxidant properties, with antioxidant ABTS efficiencies ranging from 83.5 to 100% and a quite high inhibition of Gram-positive Staphylococcus aureus bacteria, averaging over 95%. The current functionalization of PLA simultaneously confers antifogging, antioxidant, and antimicrobial properties and drives the development of a biodegradable and environmentally friendly composite material using green chemistry principles

Advanced technologies for pre-treatment of sludge and development of new materials from the same

Blato, ki je nastaja na čistilnih napravah odpadnih voda, je precejšn problem. Ustrezno ravnanje z odpadno vodo je prioriteta pri upravljanju z vodami. Ne glede na to, v kolikšni meri se čistijo odpadne vode, te tvorijo določeno količino blata (0,5 kg blata/m³ odpadne vode) – pojavlja se torej kot stranski produkt, ki ga je treba odstraniti v skladu z zakonskimi predpisi. V pričujočem delu so podrobneje opisani možni zaključni postopki in odlaganje blata iz čistilne naprave za odpadne vode. V magistrskem delu smo se osredotočili na ponovno uporabo blata - za razvoj novih materialov, ki se lahko uporabljajo na področju kmetijstva kot gnojilo/ojačevalci humusa ali pa za toplotno obdelavo. Pred začetkom eksperimentalnega dela smo morali blato dehidrirati. Testiranje blata v laboratoriju za tvorbo potencialnega goriva je potekalo s kemijsko analizo, merjenjem vsebnosti vlage, določevanje kurilne vrednosti in klora.. V drugem poskusu smo na osnovi kalilnega in rastnega testa pridobili rezultate, ki kažejo, ali je blato primerno za uporabo v kmetijske namene.Sludge, which is produced as a product on waste water treatment plants, is a major environmental problem the world. Adequate waste water treatment is a priority for water management. Regardless of the concept of wastewater treatment, a certain amount of sludge (0,5 kg of sludge / m³ of waste water) is produced as a by-product that needs to be disposed of in accordance with legal requirements. Possible procedures for the final treatment and disposal of sludge from the wastewater treatment plant are detailed in this document. In the graduation work we focused on the recycling of sludge, that is, on the development of new materials that will be applicable in the field of agriculture as fertilizer/humus enhancersand for thermal treatment. Before the very beginning of the experimental work, the sludge had to be dehydrated. The sludge testing in the laboratory for the development of a potential fuel consisted of a chemical analysis, a measurement of the moisture content, the determination of the heating value and chlorine. In the second experimental work on the basis of the growth and calorie test, we obtained results that show us whether the sludge is suitable for agricultural purposes

Cellulose–Chitosan Functional Biocomposites

Here, we present a detailed review of recent research and achievements in the field of combining two extremely important polysaccharides; namely, cellulose and chitosan. The most important properties of the two polysaccharides are outlined, giving rise to the interest in their combination. We present various structures and forms of composite materials that have been developed recently. Thus, aerogels, hydrogels, films, foams, membranes, fibres, and nanofibres are discussed, alongside the main techniques for their fabrication, such as coextrusion, co-casting, electrospinning, coating, and adsorption. It is shown that the combination of bacterial cellulose with chitosan has recently gained increasing attention. This is particularly attractive, because both are representative of a biopolymer that is biodegradable and friendly to humans and the environment. The rising standard of living and growing environmental awareness are the driving forces for the development of these materials. In this review, we have shown that the field of combining these two extraordinary polysaccharides is an inexhaustible source of ideas and opportunities for the development of advanced functional materials