小中大【求助】用分光光度计测量MLSS的方法
用分光光度计测量MLSS的方法，而且文中说方法较稳定。但本人尝试过，效果不佳，由于活性污泥混合液不是均匀溶液，所以吸光度跳动很大。我想可能是我哪里有疏忽。
想请问各位大虾有没有用过这个方法的，具体做法是咋样的？
我的实验方法就是在运行稳定的活性污泥系统中取活性污泥若干，在离心机中离心并清洗数次后，放在反应装置中序批培养，定期测量混合液在比色皿里在670nm波长下测吸光度，并用差重法测MLSS。测量吸光度前没有再次进行离心处理，就直接取样测量的。
参考文献如下：
The mixed liquor suspended solids (MLSS) concentration was calculated by means of a calibration curve (Eq (1)), which was obtained experimentally, by the following procedure. Five 500ml conical flasks were filled with 200ml of growth medium, inoculated with activated sludge and placed in a shaker at 30 ◦C. Several hours later,when sufficient growthwas observed, the monitoring of optical densities and biomass concentrations were performed as follows: every hour (for the next 4 h), 30ml of mixed liquor were extracted from each flask; the optical densitywasmeasured using 1ml of the sample,whilst the rest was immediately filtered through pre-weighed filter paper with a size cutoff of 0.2 m. The filter was washed twice with 100ml of deionisedwater and the filter paperwas thenweighted,
after drying at 105 ◦C. Optical densities (ABS) were plotted against dry weight, yielding the curve of Eq. (1).
MLSS = 1.1519ABS + 0.1232
来源：P. Gikas, P. Romanos / Journal of Hazardous Materials B133 (2006) 212–217
Microbial growth evolution was carried out by monitoring the MLSS concentration along the time in a VARIAN-CARY 1E spectrophotometer. During batch growth, liquid samples were withdrawn and centrifuged immediately to separate bacteria from the liquid medium. Depending on turbidity, samples were diluted with water
by a factor of 2±8 and then centrifuged at 4000 rpm for 20 min to precipitate the bacteria. After centrifugation, the supernatant was removed, cell pellet was resuspended into water and cell density was then determined by optical density at 450 nm. Optical density measurements of the activated sludge culture were converted into MLSS concentration by means of this calibration curve:
=ÿ 2.118(20.941)+548.74(24.68)ABS, where ABS is the absorbance value and is the mixed liquor suspended solids concentration (expressed as mg
biomass/l). The coecient of correlation for this linear re gression was r2=0.998.
来源：Wat. Res. Vol. 32, No. 5, pp. 1355-1362, 1998
