1.
[Characteristics and Mechanism of Biological Nitrogen and Phosphorus Removal Granular Sludge Under Carbon Source Stress].
Qin, SY, Chen, W, Ma, ZR, Liu, XY, Chen, XG, Yu, WT, Xia, YY, Huang, J
Huan jing ke xue= Huanjing kexue. 2017;(6):2461-2469
Abstract
In SBR reactor, the mature granular sludge fed with sodium acetate was gradually cultivated with different carbon sources (sodium acetate/glucose ratio was 1:0, 3:1, 1:1, 1:3 and 0:1, in terms of COD, respectively). During the five stages, the physical, biochemical properties, extracellular polymeric substances (EPS), phosphorus fractions and nitrogen and phosphorus removal efficiency of granular sludge were studied. 705 days' experimental results were showed as follows. At stage Ⅳ, the granular sludge had the smallest diameter of 0.5 mm; moreover the phosphorus release/uptake rate, denitrification rate and the total phosphorus (TP) content were the lowest. While at stages Ⅰ and Ⅱ, the phosphorus release/uptake and denitrification rates were the highest, meanwhile, the TP content reached up to 72.36 mg·g-1, and the EPS content was about 350 mg·g-1, as a result, the nitrogen and phosphorus removal efficiencies were both over 94%. Nevertheless at stage Ⅴ, the biochemical rates were slightly slower than values of stages Ⅰ and Ⅱ, simultaneously the TP, glycogen and EPS contents in sludge were maintained at 69.60 mg·g-1, 224.18 mg·g-1 and 200 mg·g-1, respectively, while high nitrogen and phosphorus removal efficiency was obtained. During all stages, Ca-P was the main phosphorus fraction, and inorganic phosphorus(IP) was closely related to phosphorus removal of granular sludge.
2.
[Effects of application of N, P and K and plant density on growth of Artemisia annua and yield of artemisinin].
Yang, S, Yang, X, Huang, J, Li, L
Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica. 2009;(18):2290-5
Abstract
OBJECTIVE To study the effects of different doses of fertilizer N,P and K and different plant densities on the growth of Artemisia annua and the yield of artemisinin which provides a scientific basis for the A. annua cultivation and artemisinin production. METHOD Field experiment with an orthogonal experimental design L16(45) was applied. RESULT N, P and K in moderate supplies increased significantly total biomass, leaf yield, artemisinin content in leaf and artemisinin yield under both per plant and per plot, with N and K having more effective on the artemisinin content in leaves than P. Ample N benefited the formation of leaf yield, but excess N had a significant negative effect on artemisinin content. Extra supply of P or K had hardly obvious father positive efficiency, nor negative on artemisinin content. The plant density had strong negative effects on total biomass, leaf output and artemisinin yield of single plant (per plant), but obvious positive effects on the same indices of population (per plot) with the moderate densities due to the enlarging numbers of the population; over crowded density significantly decreased artemisinin content and artemisinin yield per plot. By multiple comparison, the treatment 12 (N3P4K2 density 3) which produced the highest yields of artemisinin and artemisinin-rich leaf per plot was selected as the best in the experiment. CONCLUSION Fertilization quantities of N, P and K fertilizer and moderate density were essential for A. annua growth and artemisinin production. The optimal application of N, P and K were respectively 300 (N), 150-300(P2O5), 210(K2O) kg x hm(-2) and the optimum density was 25 000 plant x hm(-2) nearby the test area in Chongqing.