Ildikó Bodnár

Fast microwave-mediated bulk polycondensation of D,L-lactic acid

The polycondensation of D,L-lactic acid upon microwave irradiation was studied. The results of polycondensation by means of microwave were compared to those obtained from conventional heating of lactic acid at 100°C, and it was found that the reaction proceeds with much higher rate upon microwave irradiation. The oligomer mixtures formed were investigated by means of matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). The molecular mass of the poly(lactic acid) formed under microwave irradiation was found to increase with irradiation time, and the formation of cyclic oligomers after 20 min of reaction time was also revealed.

Optimum conditions for the synthesis of linear polylactic acid-based urethanes

The reactions of polylactic acid (PLA) oligomers and isocyanates (4,4′-diphenylmethane diisocyanate and toluene diisocyanate) are reported. The effects of the reaction conditions, that is, the reaction time, reaction temperature, molar ratios, isocyanates, and catalyst, on the number-average molecular weight (Mn ) are demonstrated. The optimum reaction conditions are determined by the synthesis of relatively high Mn PLA-based linear polyurethanes. The structure of the polymer samples was investigated with dynamic light scattering, 1H NMR, IR, and matrix-assisted laser-desorption ionization time-of-flight mass spectroscopy (MALDI-TOF MS).

UTILIZATION OF MODERN ANALYTICAL TECHNIQUES FOR THE ANALYSIS OF HOUSEHOLD GENERATED GREYWATER SAMPLES

Detailed analysis of household generated greywater (GW) samples is an essential task for the design of treatment systems before reuse. In this paper modern analytical methods will be discussed, which were applied to determine the ionic and elemental concentration of different GW samples. Ion chromatography (IC) and Microwave plasma atomic emission spectrometry (MP-AES) methods were used to spoor the composition of GW samples. It was shown that from the IC results and from calculated parameters (Na ee% and SAR) the application of raw or treated GW flows for irrigation is controlled. According to the elemental concentration, GW samples from laundry/kitchen sink and dishwasher proved to be the most contaminated compared to drinking water, while the concentration of the measured elements did not elevate as significantly in GW samples from shower/bathtub.

Characterization of greywater sources on the base of organic content and microbial quality

Abstract The recycling of greywater for non-potable water applications, such as toilet flushing or irrigation, is a potential solution to reduce potable water consumption. To estimate the quality of raw greywater samples, we measured several physical, chemical and biological parameters. We used Hygiene Monitor test kits to determine microbiological presence in the samples. The greywater samples showed a high variability for all the measured parameters. In general, we found that greywater sources had lightly alkaline character with a considerable inorganic and organic content. About half of the analyzed samples can be characterized as highly contaminated water source with organic substance. The average BOD5 and DOC values of greywater samples were 429 ± 410 mg l−1 and 341 ± 348 mg l−1. The samples showed high similarity concerning the total plate counts parameter (range from 5 to 6 log10 cfu ml−1). Among the three greywater sources, the samples from dish sources showed the lowest coliform content (3.9 log1...

Investigation of chemical parameters along the Nagy Brook

Abstract Several small and big water streams cut across Hungary; the protection of these water resources is in our common interest. To perform this protection, it is necessary to carry out extensive condition surveys of these surface waters. Unfortunately, our surface water streams are not properly investigated; it is true especially for the small ones. That is why we started to study the water quality of Nagy Brook, which is loaded by many point sources of pollution. During our work we have done measurements on spot and in laboratory, as well. In this paper we are presenting only those results which were measured on the spots along the Nagy Brook. Our results demonstrate how large the effect of inflowing treated wastewater is on the quality of a seasonal water stream and how the water level affects the studied parameters and what kind of the chemical and ecological water conditions can be developed under these circumstances.