Homoarginine, ß-ODAP, and asparagine contents of grass pea landraces cultivated in Turkey.

The seeds of grass pea (Lathyrus sativus L.), a drought tolerant crop, were analysed for quantitative determination of the free amino acids ß-N-oxalyl-l-α,ß-diaminopropionic acid (ß-ODAP), homoarginine and asparagine by a simple and fast capillary electrophoretic method. In boric acid (80mM, pH 8.0) running buffer system, not only were α and ß-ODAP successfully separated, but also an efficient sample stacking was achieved during hydrodynamic sample introduction. The validated method was used for quantification of ß-ODAP, homoarginine and asparagine in seed extracts of 52 Lathyrus local landraces from various regions of Turkey and one released cultivar. The concentration ranges of amino acids were found as 0.21-1.27% (w/w) for homoarginine, 0.10-0.87% (w/w) for ß-ODAP and 0.006-0.47% (w/w) for asparagine. A positive correlation between homoarginine and ß-ODAP quantities in seeds of 53 Lathyrus local landraces was shown to exist (r(2)=0.649).

Wet oxidation: a pre-treatment procedure for sludge.

Wet oxidation process is specially effective for wastes with a high organic matter which can not be removed by conventional treatment methods. The digested and raw activated sludges of PAKMAYA yeast factory are treated by wet oxidation process. The liquid-phase organic matter concentration [as total organic carbon (TOC)] was increased by 16.5% in 10 min during the wet oxidation in the presence of Cu as catalyst and H2O2. Lenghtening the period of the wet oxidation, the TOC-concentration was increased by 66% in 120 min. The biodegradability of the sludge after wet oxidation process was also examined. A very little development in the biodegradability was observed, when wet oxidation was applied as pre-treatment to the digested sludge (5% decrease as TOC, in the presence of Cu catalyst and H2O2). However, in the case of digestion of the raw sludge after the application of wet oxidation, the biodegradability increased significantly (approximately 75%, as TOC). Moreover, wet oxidation improved the ability of settling of sludge solids, as well as enhancing the treatment efficiency. Finally, the volume of settled solids was decreased by 80% in the presence of Cu and H2O2. NH3+-N, NO2(-)-N and NO3(-)-N concentrations in the supernatant decreased with the wet oxidation. pH value of the sludge increased from 6.6 to 7.8-8.0. Since stable sludge was taken from the digester where the nitrification process was progressing, a decrease in the nitrite concentration, with an increase in nitrate was observed in the digestion continuing after the wet oxidation pre-treatment. However, in the raw activated sludge, there was a nitrite formation only in the non-pretreated sludge.

Adsorption of phosphate onto pumice powder.

The adsorption of phosphate onto pumice powder was studied as a function of time, pH and total dissolved phosphate concentration. Phosphate removal efficiency was found to be more than 80%. The adsorption reaction was considered to be a reversible reaction at which a forward first order reaction is opposed by a second order reaction. The reaction rate constant k was calculated as 28.31 ± 2.37×10-3. Phosphate adsorption data had a good fit to Freundlich adsorption isotherm at pH 3, 5, 7 and 9. In the presence of NaCl, Na2SO4, MgClg, CaCl2, NaF and urea, the adsorption was slightly affected.