漂白剂的制造技术和最近动向

本文叙述了漂白剂的制造工艺和漂白活化剂及有机过酸的前景。

Pedogenic Carbonate and Soil Dehydrogenase Activity in Response to Soil Organic Matter in Artemisia ordosica Community

Little attention has been paid to the role of soil organic matter （OM） in the formation of pedogenic carbonate in desert soils. The relationships among soil OM, soil dehydrogenase activity （DHA）, and soil CaCO3 in a plant community dominated by Artemisia ordosica, located on the eastern boundary of Tcngger Desert in the Alxa League, Inner Mongolia, China, were studied to understand whether OM was directly involved in the formation of pedogenic carbonate. The results showed that DHA and CuCO3 positively correlated with OM content, and DHA, OM, and CaCO3 were correlated with each other in their spatial distribution, indicating that abundant OM content contributed to the formation of CaCO3. Therefore, the formation of pedogenic CaCO3 was a biotic process in the plant community dominated by A. ordosica.

Effect of organic acid during the fermentation of vegetable

The technology of anaerobic digestion of sewage and solid wastes regains people＇s attention, mainly due to high price of fossil fuel nowadays in most recent years. The main topic for batch test is to study the inhibitory effect and boundary conditions of organic acid （propionic acid） to anaerobic digesters. High concentrations ofpropionic acid are achieved by direct dosage of the acid. As it is thought to be highly inhibitory to the digester, we are expecting that： （1） the production rate of methane declines and finally stops when the acid gradually accumulates; （2） the propionic acid will displace stronger inhibition under lower pH values. The results of the batch tests will assist engineers to better control anaerobic digesters and react to potential digester crises caused by propionic acid before it is too late.

The degradation of organophosphorus pesticides by means of sodium percarbonate

The factors and mechanisms of oxidative degradation of three organophosphorus pesticides （dichlorvos, methamidophos and phoxim） were studied with sodium percarbonate （SPC） as a solid oxidant. The result showed that SPC has highly activity in degrading these organophosphous pesticides. The most efficient degradation of pesticides occurred under basic conditions and the degradation rates increased with time extension and high temperature. The degradation of organophosphorus pesticides was expected to get even better results at lower initial concentration. Furthermore, we analyzed the intermediate products by NMP, spectrometry. On the basis of the analytical result, the oxidative degradation mechanism was proposed for each organophosphous pesticide. It is significant to understand the environment chemistry of organophosphorus pesticides in environmental system.

Sequestration of carbon as carbonate in the critical zone：insights from the Himalayas and Tibetan Plateau

The carbon pool stored in soil carbonate is comparable to the soil organic carbon.Therefore,secondary calcite precipitation in supersaturated catchment could be an important,yet poorly constrained,carbon sink within the modern global carbon cycle.The chemical analysis of some dissolved species transported by rivers,such as elevated Sr/Ca and Mg/Ca ratios but also heavy stable Ca isotopic compositions,witness the formation of secondary calcite in rivers draining arid regions.However,in areas affected by active tectonics and rapid physical erosion,co-variations in the fluvial Sr/Ca and Mg/Ca ratios could also be related to incongruent carbonate weathering processes.Here,we present a model to assess the roles played by incongruent carbonate dissolution and secondary calcite precipitation in modern weathering processes.We tested and applied the model to rivers draining the Himalayan–Tibetan region.The results suggest that regional aridity in the drainage basin promotes carbon sequestration as secondary carbonate but that for a given runoff,incongruent dissolution of carbonate possibly related to rapid physical erosion amplifies such sequestration.The isotopic compositions(^(13)C/^(12)C and^(18)O/^(16)O)of detrital carbonate transported by the main rivers in South and South-East Tibet imply that around 1%of the suspended material transported by those rivers corresponds to secondary carbonate and can represent between 5%and 15%of the alkalinity flux.Most of these alkalinity transported as particulate material is,nevertheless related to the weathering of carbonate lithologies and is also subjected to dissolution prior its final storage in sedimentary basins.However,on glacial-interglacial timescale this will amplify the significant role of mountain weathering on climatic variations.

Dynamic Regulation of Nitrogen and Organic Acid Metabolism of Cherry Tomato Fruit as Affected by Different Nitrogen Forms

Cherry tomatoes （Lycopersicon esculentura Mill., cv. hongyangli） were hydroponically cultivated in a greenhouse to determine the effect of different nitrogen （N） forms on organic acid concentration and the activities of related enzymes involved in nitrogen and organic acid metabolism during cherry tomato fruit development. The results showed that fruit nitrate reductase （NR） activity was much higher following treatment with 100% NO3 and 75% NO3 ＋ 25% NH＋ than with 100% NH＋ except at maturity. Glutamine synthetase （GS） activity trended downward during fruit development under all three treatments. Plants fed 100% NH＋ had the lowest fruit citrate and malate levels at maturity, with the highest malate concentration at an early stage. The activity of phosphoenolpyruvate carboxylase （PEPC） was found to be in accord with the malate concentration with every N source. Under all three N forms, the citrate synthase （CS） activity peaked one week before the citrate concentration.