No abstract

No abstract

Greywater (GW) has attracted global attention as an alternative water source over the last few decades. GW treatment and reliable reuse require the overall qualitative characterization of samples from different sources. This paper represents an investigation of household-generated GW in the Northern Great Plain Region of Hungary. Modern and reliable analytical techniques and instruments (ion chromatography, microwave plasma atomic emission spectrometry, Zetasizer Nano Z analysis, etc.) were applied for the determination of the main pollutants and the preparation and specification of the potential treatment methods for indoor or outdoor GW reuse. It was shown that the shower/bathtub fraction must be collected separately from other sources based on its low organic matter (DOC<87. , Cu<0.15 mg L -1 , Ba<0.38 mg L -1 ) concentrations. In particular, laundry and kitchen sink or dishwasher GW were the most loaded streams. The current study demonstrated that there are no significant limitations for implementing GW reuse systems in Hungarian households but that treatment is necessary before reuse. Further research is needed to adapt treatment methods for the specifics of Hungary.

The melt polycondensation of D,L-lactic acid was studied by the MALDI-TOF MS method at temperatures ranging from 100 to 220 °C. At low temperature, i.e., up to 120 °C, linear, and at higher temperature both linear and cyclic oligomers were formed. The ring-chain equilibrium was investigated in detail and the concentration-based equilibrium constants (K x ) and their dependence on the degree of polycondensation and on the temperature were determined. It was also found that the molecular size distribution of the linear chain oligomers obeys to "the most probable distribution". A detailed investigation also showed that the ring size distribution of the cyclic oligomers follows the Jacobson-Stockmayer theory.

The reaction between lactic acid and diphenylmethane diisocyanate was studied by 1 H NMR, 13 C NMR, and matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy. The structure of the oligomers formed was also investigated and supported by using the postsource decay method. Analysis of the products revealed that, besides linear chain copolymer formation, branching and homooligomerization of lactic acid also took place. A mechanism is suggested for the cooligomerization processes.