Five new synonyms for Impatiensprocumbens (Balsaminaceae) in China.

In the revision on the genus Impatiens L. in China, we found that there were synonyms amongst some species. Impatiensprocumbens Franch. morphologically resembled I.reptans Hook.f., I.crassiloba Hook.f., I.ganpiuana Hook.f., I.atherosepala Hook.f. and I.rhombifolia Y.Q.Lu & Y.L.Chen. After a thorough morphological study, based on original literature, type specimens and field surveys, it was found that the above six species of Impatiens had no substantial differences in morphological characters and there was continuity in geographical distribution. Therefore, we determined that I.reptans, I.crassiloba, I.ganpiuana, I.atherosepala and I.rhombifolia are the synonyms of I.procumbens. At the same time, we present the color photographs, supplementary descriptions of morphology, and geographical distribution. The lectotype of I.procumbens and I.reptans are also designated here.

Impatiensbijieensis (Balsaminaceae), a new species from karst plateau in Guizhou, China.

Impatiensbijieensis X.X. Bai & L.Y. Ren, sp. nov. from northwest Guizhou Province, China, is described and illustrated. This new species is distributed discontinuously in Jiulongshan, Dafang County and Dajiucaiping, Hezhang County, both of which are in the Wumeng Mountain area, a karst plateau landform. The new species is morphologically similar to I.pterosepala Hook.f., I.lasiophyton Hook.f. and I.leptocaulon Hook.f. in height and flower shape and it especially resembles I.lasiophyton in pilosity. However, it differs in its deep purplish-red flower, 2-lobed lower sepal apex and cylindrical capsule. A detailed description, colour photographs and a provisional IUCN Red List assessment are provided along with discussions of its geographical distribution, ecology and morphological relationships with other similar species.

Impatiensliupanshuiensis (Balsaminaceae), a new species from Guizhou, China.

Impatiensliupanshuiensis (Balsamianceae), belonging to I.subgen.Impatiens, is recognised as a new species from Guizhou, China and it is described and illustrated. It is morphologically similar to I.xanthocephala W.W. Sm. in its yellow flowers, extremely small basal lobes on lateral united petals, broadly-dolabriform distal lobes and funnelform lower sepal. However, it is distinctive in the number of lateral sepals, teeth on the margin of lateral sepals, the recurvature of the dorsal petal, the number of lateral veins, the shape and size of the lamina and the type of lamina margin. A detailed description of the new species and colour photographs are provided. Its geographical distribution and morphology are also compared to similar species.

Phosphorus accumulation by bacteria isolated from a continuous-flow two-sludge system.

In this article, polyphosphate-accumulating organisms (PAOs) from a lab-scale continuous-flow two-sludge system was isolated and identified, the different phosphorus accumulation characteristics of the isolates under anoxic and aerobic conditions were investigated. Two kinds of PAOs were both found in the anoxic zones of the two-sludge system, one of them utilized only oxygen as electron acceptor, and the other one utilized either nitrate or oxygen as electron acceptor. Of the total eight isolates, five isolates were capable of utilizing both nitrate and oxygen as electron acceptors to uptake phosphorus to some extent. And three of the five isolates showed good phosphorus accumulative capacities both under anoxic or aerobic conditions, two identified as Alcaligenes and one identified as Pseudomonas. Streptococcus was observed weak anoxic phosphorus accumulation because of its weak denitrification capacity, but it showed good phosphorus accumulation capacity under aerobic conditions. One isolates identified as Enterobacteriaceae was proved to be a special species of PAOs, which could only uptake small amounts of phosphorus under anoxic conditions, although its denitrification capacity and aerobic phosphorus accumulation capacity were excellent.

Simultaneous phosphorus and nitrogen removal in a continuous-flow two-sludge system.

The ability of simultaneous biological phosphorus and nitrogen removal was investigated in a lab-scale continuous-flow two-sludge system. Alternating anaerobic and anoxic conditions were combined with contact oxidation stage for treating raw municipal wastewater. Long-term experiments showed that the contradiction of competing for the organic substrate between denitrifying bacteria and PAOs (phosphorus accumulating organisms) in traditional phosphorus and nitrogen removal system has been resolved. The system can adapt to low influent COD/TN ratio (C/N). Furthermore the SRT (sludge retention time) of nitrifying sludge and denitrifying phosphorus removal sludge can be controlled at optimal conditions respectively. The removal efficiency of COD, TP, TN, and NH4-N was 81.78%, 92.51%,75.75%, and 84.47% respectively. It was also found that the appropriate influent C/N should be controlled at the range of 3.8-6, while the optimal C/N to the system ranged between 4-5, and the BFR (bypass sludge flow rate) should be controlled at 0.35 around.

[Cultivation and enrichment of denitrifying phosphorus removal bacteria (DPB) in denitrifying biological nutrient removal process].

The cultivation of the denitrifying phosphorus removal bacteria (DPB) in biological nutrient removal system will directly affect the removal efficiency of the nutrients in wastewater such as nitrogen and phosphorus, and the stability of the process. For this reason, a new BNR process, which is called double-sludge denitrifying-nitrogen and phosphorus removal process, was designed. In order to create a good anaerobic/anoxic alternating environment for DPB, gradual transition of training methods were used to make DPB natural selection, and then finally, screened the dominated DPB bacteria. The results indicated that the anaerobic/aerobic (A/O) operation mode can induce induction of PAOs rapidly by 15 days intermittent aeration. The proportion of DPB/PAOs in the reactor was aggrandized in the second phase (about 25 days' inducement) by reducing the aeration time in aerobic phase gradually and adding nitrate in anoxic phase, which is called anaerobic/aerobic/anoxic (A/O/A) mode; finally, the strictly alternating environmental anaerobic/anoxic conditions for DPB were used to induce and enrich the target DPB bacteria for 19 days by a gradual transition of enrichment culture. The successful domestication and cultivation of DPB provides a new method to remove nitrogen and phosphorus efficiently and steadily in municipal wastewater.