An extensive use of plastic material, which is a characteristic of modern society, is increasing the amount of plastic waste in the environment. Accordingly, plastic pollution has become a global ...environmental problem. The problem is particularly related to microsized and nanosized plastic particles which have become environmental contaminants of emerging concern. This research was focused on ecotoxicological aspects of 5 the most common plastic substances: polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), and polyethylene terephthalate (PET); all substances were in form of microplastics. The used test organism was freshwater microalgae
Chlorella
sp. and inhibition of the algal growth after 3-day exposure was measured. The experimental domain included microplastics in range 10–1000 mg/L and sizes 100–700 µm. Response surface modeling was applied in order to analyze the influence of these two parameters and statistical analysis of the obtained models was performed. The significance level was 95%. The obtained inhibitions were relatively low (< 6.79%) but
Chlorella
sp. showed sensitivity to changes in both tested parameters. A general behavior that included inhibition increase with higher concentration values and lower particle sizes was observed. The exception was PP where only the concentration proved to be significant parameter; the influence of the particle size remained insignificant for the selected experimental domain. Hormesis appears likely in PE and PP cases at particle sizes and concentrations that are below the experimental domain. Determined adverse influence of the applied plastics followed the order: PVC > PET > PS > PE > PP.
Graphical abstract
Dasatinib (DAS), a potent anticancer drug, has been subjected to formulation enhancements due to challenges such as significant first-pass metabolism, poor absorption, and limited oral ...bioavailability. To improve its release profile, DAS was embedded in a matrix of the hydrophilic polymer polyvinylpyrrolidone (PVP). Drug amorphization was induced in a planetary ball mill by solvent-free co-grinding, facilitating mechanochemical activation. This process resulted in the formation of amorphous solid dispersions (ASDs). The ASD capsules exhibited a notable enhancement in the release rate of DAS compared to capsules containing the initial drug. Given that anticancer drugs often undergo limited metabolism in the body with unchanged excretion, the ecotoxicological effect of the native form of DAS was investigated as well, considering its potential accumulation in the environment. The highest ecotoxicological effect was observed on the bacteria
, while other test organisms (bacteria
, microalgae
sp., and duckweed
) exhibited negligible effects. The enhanced drug release not only contributes to improved oral absorption but also has the potential to reduce the proportion of DAS that enters the environment through human excretion. This comprehensive approach highlights the significance of integrating advances in drug development while considering its environmental implications.
Poznato je da je onečišćenje plastikom postalo jedno od najvažnijih ekoloških pitanja u današnjem svijetu. Iako je stopa recikliranja plastičnih proizvoda u porastu, većina plastike još uvijek ...nekontrolirano dospijeva u okoliš. Plastika sama po sebi ne predstavlja veliku prijetnju ekosustavu za razliku od njezinih degradiranih komponenti, mikroplastike (MP) i nanoplastike (NP), koje su zbog svoje veličine reaktivnije te se lakše transportiraju. Posljednjih godina porast ljudske potražnje, proizvodnje te uporabe proizvoda koji su izvorno u obliku MP-a i NP-a dodatno povećavaju problem onečišćenja. Jednom oslobođeni, MP i NP se više akumuliraju u kopnenom ekosustavu nego u vodenom, koji je po tom pitanju znatno više istražen. Posljedično tome, degradirane komponente plastike akumuliraju se u organizme koji žive u tlu te ih ti organizmi svojim metabolizmom mogu dodatno razgraditi (usitniti). Cilj ovog rada je dati pregled o ekotoksičnosti MP-a i NP-a upravo na gujavice kao predstavnike koljena kolutićavaca (Annelida) te na obliće (koljeno Nematoda), kao dvije najčešće skupine beskralježnjaka koje obitavaju u tlu. Ispitivanje utjecaja MP-a i NP-a na gujavicama dosad je provedeno na vrstama Eisenia fetida, Eisenia andrei i Lumbricus terrestris, dok je kao predstavnik oblića upotrijebljena vrsta Caenorhabditis elegans. Navedeni su se organizmi izlagali česticama polietilena, polistirena i polipropilena različitih veličina, kao i njihovim različitim koncentracijama. Rezultati mnogobrojnih istraživanja štetnog utjecaja navedenih polimernih materijala na ispitivane kolutićavce i nematode, mjerenog testom inhibicije stope preživljavanja i rasta, pokazuju značajan gubitak tjelesne težine, oštećenje probavila te oksidativni stres.
Microplastics (MP) are a global environmental problem because they persist in the environment for long periods of time and negatively impact aquatic organisms. Possible solutions for removing MP from ...the environment include biological processes such as bioremediation, which uses microorganisms to remove contaminants. This study investigated the biodegradation of polystyrene (PS) by two bacteria, Bacillus cereus and Pseudomonas alcaligenes, isolated from environmental samples in which MPs particles were present. First, determining significant factors affecting the biodegradation of MP-PS was conducted using the Taguchi design. Then, according to preliminary experiments, the optimal conditions for biodegradation were determined by a full factorial design (main experiments). The RSM methodology was applied, and statistical analysis of the obtained models was performed to analyze the influence of the studied factors. The most important factors for MP-PS biodegradation by Bacillus cereus were agitation speed, concentration, and size of PS, while agitation speed, size of PS, and optical density influenced the process by Pseudomonas alcaligenes. However, the optimal conditions for biodegradation of MP-PS by Bacillus cereus were achieved at γMP = 66.20, MP size = 413.29, and agitation speed = 100.45. The best conditions for MP-PS biodegradation by Pseudomonas alcaligenes were 161.08, 334.73, and 0.35, as agitation speed, MP size, and OD, respectively. In order to get a better insight into the process, the following analyzes were carried out. Changes in CFU, TOC, and TIC concentrations were observed during the biodegradation process. The increase in TOC values was explained by the detection of released additives from PS particles by LC-MS analysis. At the end of the process, the toxicity of the filtrate was determined, and the surface area of the particles was characterized by FTIR-ATR spectroscopy. Ecotoxicity results showed that the filtrate was toxic, indicating the presence of decomposition by-products. In both FTIR spectra, a characteristic weak peak at 1715 cm−1 was detected, indicating the formation of carbonyl groups (−C=O), confirming that a biodegradation process had taken place.
The improper disposal of plastics is a growing concern due to increasing global environmental problems such as the rise of CO
emissions, diminishing petroleum sources, and pollution, which ...necessitates the research and development of biodegradable materials as an alternative to conventional packaging materials. The purpose of this research was to analyse the properties of biodegradable polymer blends of thermoplastic potato starch (TPS) and polylactide, (PLA) without and with the addition of citric acid (CA) as a potential compatibilizer and plasticizer. The prepared blends were subjected to a comprehensive physicochemical characterization, which included: FTIR-ATR spectroscopy, morphological analysis by scanning electron microscopy (SEM), determination of thermal and mechanical properties by differential scanning calorimetry (DSC), water vapour permeability (
), as well as biodegradation testing in soil. The obtained results indicate an improvement in adhesion between the TPS and PLA phases due to the addition of citric acid, better homogeneity of the structure, and greater compatibility of the polymer blends, leading to better thermal, mechanical and barrier properties of the studied biodegradable TPS/PLA polymer blends. After conducting the comprehensive research outlined in this paper, it has been determined that the addition of 5 wt.% of citric acid serves as an effective compatibilizer and plasticizer. This supplementation achieves an optimal equilibrium across thermal, mechanical, morphological, and barrier properties, while also promoting material sustainability through biodegradation. In conclusion, it can be stated that the use of thermoplastic starch in TPS/PLA blends accelerates the biodegradation of PLA as a slowly biodegradable polymer. While the addition of citric acid offers significant advantages for TPS/PLA blends, further research is needed to optimize the formulation and processing parameters to achieve the desired balance between mechanical strength, thermal and barrier properties and biodegradability.
The harmful effects of microplastics are not yet fully revealed. This study tested harmful effects of polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), and ...polyethylene terephthalate (PET) microplastics were tested. Growth inhibition tests were conducted using three microorganisms with different characteristics:
sp.,
, and
. The growth inhibition test with
sp. is relatively widely used, while the tests with
and
were, to our knowledge, applied to microplastics for the first time. The influence of concentration and size of microplastic particles, in the range of 50-1000 mg/L and 200-600 µm, was tested. Determined inhibitions on all three microorganisms confirmed the hazardous potential of the microplastics used. Modeling of the inhibition surface showed the increase in harmfulness with increasing concentration of the microplastics. Particle size showed no effect for
with PE, PP and PET,
with PS, and
with PP. In the remaining cases, higher inhibitions followed a decrease in particle size. The exception was
sp. with PS, where the lowest inhibitions were obtained at 400 µm. Finally, among the applied tests, the test with
proved to be the most sensitive to microplastics.
Utjecaj COVID-19 obrazaca ponašanja na ekosustave Pamela Bubaš; Dora Hećimović; Filip Mikuličić ...
Kemija u industriji; časopis kemičara i tehnologa Jugoslavije,
01/2024, Volume:
73, Issue:
1-2
Journal Article
Peer reviewed
Open access
Pandemija COVID-19 prouzročila je promjenu globalnoga razmišljanja i donijela svijetu neke nove i specifične obrasce ponašanja. Pandemijsko je razdoblje gotovo u potpunosti usmjerilo fokus na ...globalnu zdravstvenu krizu te su neke pretpandemijske cirkularne vrijednosti bivale zanemarivane. Stavljajući zdravlje svojih građana kao prioritetno, mnoge su se države i vlade ponovno okrenule linearnome gospodarstvu. Također, svjetska je populacija počela rapidnom brzinom konzumirati određene farmaceutike, pojavilo se (pre)naglašeno potenciranje osobne higijene i upotrebe dezinfekcijskih sredstava te se smanjenjem ljudskog kontakta ubrzano povećala potražnja i upotreba jednokratne plastike. Pojedini dijelovi industrije privremeno su se ugasili, no pojedini su sektori radili pojačanim intenzitetom, a prenapučenost zdravstvenih ustanova i neadekvatno zbrinjavanje medicinskog otpada i bolničkih otpadnih voda zadalo je specifičan udarac svjetskim ekosustavima. Tako se u okolišu odjednom našla neočekivano velika količina raznih farmaceutika, proizvoda za osobnu higijenu, jednokratne plastike, proizvoda za osobnu zaštitu, kao i medicinskog opasnog i neopasnog otpada. Stoga je iznimno važno sagledati širu sliku pandemijskih posljedica po okoliš te shodno tome donijeti adekvatna rješenja glede sprječavanja i smanjenja onečišćenja okoliša uzrokovanog pandemijom. Pojedina pandemijska ponašanja treba promijeniti, nastalu štetu sanirati i usmjeriti globalnu proizvodnju ka nekim novijim i održivijim tehnologijama. U ovome će se radu dati sažet pregled posljedica globalne zdravstvene krize na biosferu te perspektiva za potencijalno rješavanje nastalih problema i suzbijanje budućih katastrofa.
In this study, a screening of the efficacy of a microbial consortium of bacteria and fungi isolated from activated sludge, river sediment, and compost for the degradation of LDPE/TPS was performed. ...According to the morphological and biochemical characterization, eight bacteria, Bacillus sonorensis, Bacillus subtilis, Lysinibacillus massiliensis, Bacillus licheniformis, Bacillus indicus, Bacillus megaterium, Bacillus cereus, and Pseudomonas alcaligenes, five molds, Aspergillus sp. 1, Aspergillus sp. 2, Trichoderma sp., Rhizopus sp., Penicillium sp., and Alternaria sp., and a yeast, Candida parapsilosis, were identified. The first experiment E1 was inoculated with microorganisms isolated from activated sludge and river sediment, and E2 with microorganisms isolated from compost. In both experiments, different types of polymeric materials, low density polyethylene (E1-1 and E2-1), thermoplastic starch (E1-2 and E2-2), low density polyethylene + thermoplastic starch (E1-3 and E2-3), low density polyethylene + thermoplastic starch + styrene-ethylene-styrene (E1-4 and E2-4) were added. The obtained results, weight loss, SEM, and FTIR analysis showed that the microorganisms in both experiments were able to degrade polymeric materials. The mixed culture of microorganisms in experiments E1-2 and E2-2 completely degraded TPS (thermoplastic starch). The percent weight losses of LDPE, LDPE+20% TPS, and LDPE+20% TPS+SEBS in experiment E1 were 3.3184%, 14.1152%, and 16.0062% and in experiment E2 were 3.9625%, 20.4520% and 21.9277%, respectively. SEM microscopy shows that the samples with a LDPE matrix exhibited moderate surface degradation and negligible oxidative degradation under the given conditions. FTIR/ATR data demonstrate that degradation was more intense in E2 than in E1.
Konzumiranje duhanskih proizvoda ne predstavlja samo zdravstveni već i važan ekološki problem. U prosjeku je oko 80 % opušaka odbačeno u okoliš. Najveći problem odbačenih opušaka su kemijski spojevi ...koji su štetni za ljude i okoliš te filtri koji se sporo razgrađuju u prirodi. Klasične cigarete imaju filtar napravljen od celuloznog acetata, odnosno polimernog materijala, koji nije biorazgradiv. Celulozni filtri su alternativa polimernim filtrima jer su biorazgradivi, te samim time i manje štetni za okoliš i organizme. Električne cigarete su alternativa klasičnim cigaretama zbog jednostavnijeg sastava i zbog pretpostavke da je to zdravija opcija, a ujedno je izbjegnut i problem zaostalih opušaka. Odbačene opuške možemo primijetiti u svakodnevnom životu. Pomoću vjetra i oborina transportiraju se s kopna u vodeni okoliš te još dugi niz godina otpuštaju štetne kemikalije, a s vremenom potonu na dno. Svrha ovog rada bila je razmotriti štetan učinak odbačenih opušaka na okoliš pomoću testova ekotoksičnosti. Istraženi su radovi koji ispituju ekotoksičnost na morskim i slatkovodnim vrstama u vodenom ekosustavu (bentos, plankton, nekton), kao i na kopnenim organizmima (biljke, beskralješnjaci, kralješnjaci). Istraživanja na vodenim organizmima pokazuju osjetljivost na štetne spojeve koji se nalaze u odbačenim opušcima. Također, odbačeni opušci negativno utječu i na kopneni ekosustav, što je ustanovljeno istraživanjima na mikrobiološkim zajednicama u tlu te biljkama, beskralješnjacima i kralješnjacima. Zaključno, potrebno je informirati pušače o štetnosti odbačenih opušaka u okoliš te ih educirati o pravilnom odlaganju opušaka. Štoviše, problem se može dodatno smanjiti provedbom recikliranja opušaka.
Stalni rast tržišta kave uzrokuju velike količine nastanka otpada taloga kave (OTK) koji čini i do 95 % otpada nakon konzumacije kave. OTK skriva bogatstvo različitih resursa, koje treba samo ...prevesti u neki drugi oblik, pogodan za uporabu. S druge strane, današnja prekomjerna proizvodnja plastičnog otpada uvelike uzrokuje ekološki poremećaj na globalnoj razini u gotovo svim aspektima industrije, što uzrokuje ubrzanu uporabu biorazgradivih polimera i biokompozita. Upravo zbog enormnih količina nastanka OTK i spore biorazgradnje polilaktida (PLA), u ovome istraživanju ispitana su svojstva i biorazgradivost zelenih biokompozita PLA_OTK pripremljenih umješavanjem matrice polilaktida s različitim udjelima otpada taloga kave. Toplinska svojstva biokompozita ispitana su diferencijalnom pretražnom kalorimetrijom (DSC) i termogravimetrijskom analizom (TGA). Ispitana je raspodjela veličina čestica otpada taloga kave metodom laserske difrakcije te apsorpcija vode (AV). Biorazgradnja biokompozita provedena je procesom kompostiranja tijekom 19 dana. Rezultati ispitivanja toplinskih svojstava pokazali su da OTK kao punilo ne utječe na fazne prijelaze PLA matrice, ali utječe na smanjenje toplinske stabilnosti biokompozita PLA_OTK. Rezultati ispitivanja apsorpcije vode pokazali su da povećanjem udjela OTK dolazi do povećanja apsorpcije vode u biokompozitima zbog hidrofilnog karaktera punila. Iz fotografija svjetlosnog mikroskopa vidljiv je površinski napad mikroorganizama kod biokompozita s manjim udjelom OTK, dok je dublji prodor vidljiv kod biokompozita s većim udjelom OTK kao punila.