Crinela Dumitrescu

Dr. Crinela Dumitrescu

orcid

Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
26 April 2024 in Polymers
Verified
Journal Article
Open access
PDF file
MBMarius Bumbac
Marius Bumbac
CNCristina Mihaela Nicolescu
Cristina Mihaela Nicolescu
Traian ZaharescuTraian Zaharescu
Traian Zaharescu
VGValentin Gurgu
Valentin Gurgu
CBCostel Bumbac
Costel Bumbac
CDCrinela Dumitrescu
Crinela Dumitrescu
The preparation of polymer composites that incorporate material of a biogenic nature in the polymer matrices may lead to a reduction in fossil polymer consumption and a potentially higher biodegradability. Furthermore, microalgae biomass as biogenic filler has the advantage of fast growth and high tolerance to different types of culture media with higher production yields than those provided by the biomass of terrestrial crops. On the other hand, algal biomass can be a secondary product in wastewater treatment processes. For the present study, an SBS polymer composite (SBSC) containing 25% (w/w) copolymer SBS1 (linear copolymer: 30% styrene and 70% butadiene), 50% (w/w) copolymer SBS2 (linear copolymer: 40% styrene and 60% butadiene), and 25% (w/w) paraffin oil was prepared. Arthrospira platensis biomass (moisture content 6.0 ± 0.5%) was incorporated into the SBSC in 5, 10, 20, and 30% (w/w) ratios to obtain polymer composites with spirulina biomass. For the biodegradation studies, the ISO 14855-1:2012(E) standard was applied, with slight changes, as per the specificity of our experiments. The degradation of the studied materials was followed by quantitatively monitoring the CO2 resulting from the degradation process and captured by absorption in NaOH solution 0.5 mol/L. The structural and morphological changes induced by the industrial composting test on the materials were followed by physical–mechanical, FTIR, SEM, and DSC analysis. The obtained results were compared to create a picture of the material transformation during the composting period. Thus, the collected data indicate two biodegradation processes, of the polymer and the biomass, which take place at the same time at different rates, which influence each other. On the other hand, it is found that the material becomes less ordered, with a sponge-like morphology; the increase in the percentage of biomass leads to an advanced degree of degradation of the material. The FTIR analysis data suggest the possibility of the formation of peptide bonds between the aromatic nuclei in the styrene block and the molecular residues resulting from biomass biodegradation. It seems that in industrial composting conditions, the area of the polystyrene blocks from the SBS-based composite is preferentially transformed in the process.

1 January 2011 in Procedia - Social and Behavioral Sciences
Verified
Journal Article
Open access
LGLaura Gorghiu
Laura Gorghiu
GGGabriel Gorghiu
Gabriel Gorghiu
CDCrinela Dumitrescu
Crinela Dumitrescu
RORadu Lucian Olteanu
Radu Lucian Olteanu
AGAdina Elena Glava
Adina Elena Glava
The paper presents some aspects related to the teachers and pupils’ reactions concerning the introduction and integrating of ICT in the teaching and learning process of various branches of knowledge. The study was developed in the frame of the 118766-2004-RO-COMENIUS-2.1. Project “FISTE - A Future Way for In-Service Teacher Training across Europe” (http://fiste.ssai.valahia.ro), project co-funded by the European Commission, Education and Training, School Education: Socrates: Comenius. The analysis was performed on a sample of 245 teachers and over 2100 pupils from five European countries - Romania, Spain, Finland, Iceland and Latvia - involved in the educational process from pre-primary, primary, lower and upper secondary schools. The respondents were asked to write their opinions about the use of ICT during the teaching and learning process of different scientific topics by filling different evaluation and impact questionnaires designed by the FISTE partnership

23 May 2025 in Applied Sciences
Verified
Journal Article
Open access
PDF file
CDCrinela Dumitrescu
Crinela Dumitrescu
Claudia StihiClaudia Stihi
Claudia Stihi
DCDiana COSTINEL
Diana COSTINEL
Elisabeta-Irina GeanaElisabeta-Irina Geana
Elisabeta-Irina Geana
CCCorina Ciucure
Corina Ciucure
Petre BretcanPetre Bretcan
Petre Bretcan
In Romania, groundwater is an important source of drinking water, especially in rural areas. This study investigated the concentrations of organophosphorus, carbamate, and triazine pesticides (OPs) along with organochlorine pesticides (OCPs) in groundwater samples collected from the Titu-Sarata Plain. Sensitive analytical techniques were employed, including Ultrahigh-Performance Liquid Chromatography coupled with Q Exactive™ HF Hybrid Quadrupole-Orbitrap™ Mass Spectrometry (UHPLC-Orbitrap-MS/MS) and Gas Chromatography coupled with an electron capture detector (GC-ECD). Environmental and human health risks were assessed in the case of pesticides that exceeded the maximum allowed concentration. The environmental risk assessment (ERA) revealed significant risks associated with Phosdrin, Phorate, and pp’DDE. Additionally, particular concerns arose from the presence of Aldrin and Dieldrin, which pose a high carcinogenic risk, especially through groundwater consumption in agricultural areas. The results of this research highlight the need for the implementation of a continuous quality monitoring program for groundwater in the agricultural regions that were studied.

17 October 2025 in Foods
Verified
Journal Article
Open access
PDF file
Claudia StihiClaudia Stihi
Claudia Stihi
CDCrinela Dumitrescu
Crinela Dumitrescu
Edible wild mushrooms have considerable nutritional value, being widely used in Romania as a traditional food. Mushrooms are an important source of essential minerals for the optimal functioning of the body and can accumulate some toxic metals that affect human health, this being the reason to investigate their metal content, and the possible risks to human health associated with consuming mushrooms. Eighteen wild edible mushroom species from the forestry areas of Dâmbovița County, Romania, were analyzed for metal content using Energy-Dispersive X-ray Fluorescence with fundamental parameter methods (EDXRF-FP). The detected concentrations varied among species as follows: 6.309–88.745 mg/kg for Fe; 0.679–3.480 mg/kg for Cu; 5.115–25.942 mg/kg for Zn; 0.236–32.025 mg/kg for Mn; 0.033–4.507 mg/kg for Ni and 0.003–0.760 mg/kg for Cr. Pb and Cd were observed at low levels, with maximum concentrations of 0.886 mg/kg and 0.850 mg/kg, respectively, highlighting significant interspecific differences in metal content. The consumption of the studied mushroom species presents variable health risks associated with metal content. Adults were generally exposed to acceptable non-carcinogenic risks, although certain species possessed elevated carcinogenic risks due to Cu, Cr, and Cd. For children, non-carcinogenic risks were significant in cases of multiple species, indicating heightened vulnerability.

29 April 2024 in Polymers
Verified
Journal Article
Open access
PDF file
MBMarius Bumbac
Marius Bumbac
CNCristina Mihaela Nicolescu
Cristina Mihaela Nicolescu
Traian ZaharescuTraian Zaharescu
Traian Zaharescu
CBCostel Bumbac
Costel Bumbac
EMElena Elisabeta Manea
Elena Elisabeta Manea
CDCrinela Dumitrescu
Crinela Dumitrescu
Bio-fillers are intensively studied for advanced polymer composite circular design and production. In this context, the algal biomass may be considered an important and relatively low-cost resource, when harvested as a by-product from wastewater treatment plants. The biomass of the algal species Chlorella vulgaris is frequently used in this type of environmental process, and its macro constituents’ composition ranges from around 15–25% carbohydrates, 10–20% lipids, and 50–60% proteins. Poly (styrene-butadiene-styrene) (SBS) copolymers have a matrix composed of glassy polystyrene domains connected by flexible polybutadiene segments. Although the physical-mechanical properties of SBS copolymers recommend them for many industrial applications, they have the drawback of low biodegradability. This study aimed to assess the aerobic biodegradability of polymer composites by integrating biomass from Chlorella vulgaris at varying mass percentages of 5, 10, and 20% into SBS copolymer composites. Biodegradation tests were conducted under industrial composting conditions (58 °C and 50% relative humidity) for 180 days. The biodegradability of materials was evaluated by measuring the CO2 produced in each vessel during the study period. Potential correlations between the amount of carbon dioxide released and the percentage of biomass added to the polymer matrix were examined. Structural and morphological changes were assessed using Fourier Transform infrared spectroscopy (FTIR), thermal analysis (DSC), and scanning electron microscopy (SEM). Physical and chemical testing revealed a decrease in sample density after the industrial composting test, along with noticeable changes in melt flow index (MFI). The observed physical and chemical changes, coupled with FTIR, SEM, and DSC data, indicate increased cross-linking and higher porosity in biodegraded polymer structures with higher biomass content. This behavior is likely due to the formation of cross-linked connections between polymer chains and polypeptide chains resulting from protein degradation, enhancing connections between polystyrene units facilitated by peptide bonds with the benzene units of the styrene blocks within the polymer matrix.

21 July 2026 in Toxics
Verified
Journal Article
Open access
PDF file
CDCrinela Dumitrescu
Crinela Dumitrescu
Claudia StihiClaudia Stihi
Claudia Stihi
RIRoxana Elena Ionete
Roxana Elena Ionete
Elisabeta-Irina GeanaElisabeta-Irina Geana
Elisabeta-Irina Geana
CCCorina Ciucure
Corina Ciucure
Petre BretcanPetre Bretcan
Petre Bretcan
Groundwater is a vital resource for drinking water supply, agriculture, and industrial activities. However, contamination by organic pollutants may pose significant threats to both ecosystem integrity and human health. This study assessed the environmental and human health risks associated with polycyclic aromatic hydrocarbons (PAHs) in groundwater collected from 27 localities in the central–northeastern Romanian Plain. The concentrations of naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylene, and indeno [1,2,3-cd]pyrene were determined using high-performance liquid chromatography coupled with fluorescence detection. Benzo[a]pyrene concentrations ranged from <LOD to 0.08 ng/L, while total concentrations varied between 2.56 to 11.2 ng/L. The environmental risk associated with groundwater contamination was classified as low to moderate, with total risk coefficients ranged from 0.2 to 2.3. Potential contamination sources were identified using the diagnostic ratio method, complemented by multivariate statistical analysis, indicating predominantly pyrogenic and mixed pyrogenic–petrogenic sources. Human health risk assessment indicated that groundwater ingestion posed neither non-carcinogenic risks (Hazard Index, HI < 1) nor unacceptable carcinogenic risks. The Incremental Lifetime Cancer Risk (ILCR) values ranged from 5.7 × 10−9 to 2.2 × 10−8 for infants, 2.7 × 10−9 to 1.0 × 10−8 for children, and 1.5 × 10−9 to 6.1 × 10−9 for adults.