Biodegradation studies of polylactic acid copolymers

Medium molecular weight copolymers were synthesized by the condensation of L-lactic acid (LA), terephthalic acid (TPA) and 1,3-propanediol (PDO). The obtained copolymers were characterized for acid value, hydroxyl value and number average molecular weight. Also, the biodegradation behavior by different fungal species (A spergillus niger, A spergillu s versicolor, A lternaría altern a ta and P enicilliu m ) was performed. The degree of biodegradation was examined by weight loss. It was observed that the biodegradation of copolymer with higher quantity of lactic acid was faster and more effective than the biodegradation of copolymer with smaller quantity of lactic acid

ASSESSMENT OF Pb, Cd, Cu AND Zn AVAILABILITY FOR PLANTS IN BAIA MARE MINING REGION

In order to evaluate the mobility of heavy metals in soil from Baia Mare mining region, the total, water and DTPA extractable metal contents were determined. The results showed that despite the high total metals contents and the high percentages of plant available metals only a low percent was water soluble, indicating a potential accumulation of metals in trophic chain and a potential risk for public health. Among the investigated metals, the plant available Pb and Cd species are the most severe contaminants. Significant correlations between total and DTPA extractable metals were found for Cu (r=0.510) and Pb (0.418), and also an affinity between total and water extractable metals were identified for Cu (0.366), Pb (0.502) and Zn (0.597)

CHEMICAL AND TECHNOLOGICAL PROPERTIES OF BLACKTHORN (PRUNUS SPINOSA) AND ROSE HIP (ROSA CANINA) FRUITS GROWN WILD IN CLUJ-NAPOCA AREA

In this study, the chemical and technological properties of blackthorn (Prunus spinosa) and rose hip (Rosa canina) fruits growing wild in Cluj-Napoca area were analysed. Proximate analysis such as dry matter, moisture content, crude protein, crude fiber, ash, water-soluble, pH and mineral contents were established in this work. Al, B, Ca, K, Mg, Na, P and S were determined as major minerals. Mineral content of samples growing in Cluj-Napoca area were determined by inductively coupled plasma ICP-OES. All samples contained high amounts of K (18711-952 mg/kg), Ca (1504.22-88.06 mg/kg), Mg (972-22.7 mg/kg), P (1511-2104 mg/kg), Na (534-34.8 mg/kg), Al (26.3-1.15 mg/kg) and Fe (16.0-1.97 mg/kg). Technological properties such as projected area, porosity, bulk density, and hectoliter weight were measured. The obtained results revealed nutritional properties and mineral contents of analyzed fruit. It is very important to know the technological properties of the fruits because optimal equipment and working parameters can be used for harvesting, transportation and processing