[Qualitative-Quantitative Analysis of Rice Bran Oil Adulteration Based on Laser Near Infrared Spectroscopy].

The purpose of this study is mainly to have qualitative-quantitative analysis on the adulteration in rice bran oil by near-infrared spectroscopy analytical technology combined with chemo metrics methods. The author configured 189 adulterated oil samples according to the different mass ratios by selecting rice bran oil as base oil and choosing soybean oil, corn oil, colza oil, and waste oil of catering industry as adulterated oil. Then, the spectral data of samples was collected by using near-infrared spectrometer, and it was pre-processed through the following methods, including without processing, Multiplicative Scatter Correction(MSC), Orthogonal Signal Correction(OSC), Standard Normal Variate and Standard Normal Variate transformation DeTrending(SNV_DT). Furthermore, this article extracted characteristic wavelengths of the spectral datum from the pre-processed date by Successive Projections Algorithm(SPA), established qualitatively classified calibration methods of adulterated oil through classification method of Support Vector Machine(SVM), optimized model parameters(C, g) by Mesh Search Algorithm and determined the optimal process condition. In extracting characteristic wavelengths of the spectral datum from pretreatment by Backward interval Partial Least Squares(BiPLS) and SPA, quantitatively classified calibration models of adulterated oil through Partial Least Squares(PLS) and Support Vector Machine Regression(SVR) was established respectively. In the end, the author optimized the combination of model parameters(C, g) by Mesh Search Algorithm and determined the optimal parameter model. According to the analysis, the accuracy of prediction set and calibration set for SVC model reached 95% and 100% respectively. Compared with the prediction of the adulteration oil content of rice bran oil which was established by the PLS model, the SVR model is the better one, although both of them could implement the content prediction. Furthermore, the correlation coefficient R is above 0.99 and the Root Mean Square Error (MSE) is below 5.55 x 10(-4). The results show that the near-infrared spectroscopy technology is effective in qualitative-quantitative analysis on the adulteration of rice bran oil. And the method is applicable to analyze adulteration in other oils.

[Low carbon number fatty acid content prediction based on near-infrared spectroscopy].

The rapid prediction of the low-carbon fatty acids (C < or = 14) content in grease samples was achieved by a mathematical model established by near infrared spectroscopy combined with support vector machine regression (SVR). In the present project, near-infrared spectrometer SupNIR-5700 was used to collect near-infrared spectra of 58 samples; partial least square (PLS) was applied to remove the strange samples, and principal component analysis (PCA) was conducted on the measurements; radial basis function (RBF) kernel function was selected to establish a regression model supporting vector machine, and then detailed analysis and discussions were conducted concerning their spectral preprocessing and parameters optimization methods. Experimental results showed that by applying particle swarm optimization (PSO) the model demonstrated improved performance, stronger generalization ability, better prediction accuracy and robustness. In the second pretreatment method after PSO, when the optimization parameters are: C = 2.085, gamma = 22.20, the prediction set and calibration set correlation coefficient (gamma) reached 0.998 0 and 0.925 8, respectively; and root mean square errors (MSE) were 0.000 4 and 0.014 3, respectively. Research results proved that the method based on near infrared spectroscopy and PSO-SVR for accurate and fast prediction of the low-carbon fatty acid content in vegetable oil is feasible.

[Study of ammonium-nitrogen removal in suspended carrier biofilm reactor].

In order to improve the ammonium-nitrogen (NH4+ -N) biodegradation rate, a suspended carrier was exploited and biofilm was cultivated in three different phases in a sequencing batch reactor (SBR). A flimsy honeycomb-shape biofilm was formed between the endocentric columns on the suspended carrier,which increased the cling amount of nitrobacteria and provided the better condition for nitrobacteria. The bioreactor was operated at the temperature ranges of 24-29 degrees C and pH between 7.8 and 8.2. When the influent COD and NH4+-N concentrations varied in a range of 140-300 mg x L(-1) and 40- 78 mg x L(-1) , respectively, under 90 min aeration, the effluent concentrations were less than 40 mg x L(-1) and 2 mg x L(-1) , respectively. Under 180 min aeration, the influent COD concentration varied from 150 to 350 mg x L(-1) and NH4+-N concentration in the range of 80 - 130 mg x L (-1), the effluent concentration below 45 mg x L(-1) and 3.5 mg x L(-1), respectively. The results indicated that the ammonium-nitrogen biodegradation rate is much greater than that of the conventional activated sludge process. The active fraction of the biofilm is affected by the concentration of substrates in the bulk liquid, the actual metabolic rates within the biofilm, and the thickness of the biofilm. The suspended carrier configuration used in this investigation and the method of cultivating biofilm are beneficial for decreasing biofilm thickness, for increasing the activated biomass of nitrobacteria, and for increasing surface area of the biofilm relative to the volume of the reactors, which insulting in a high rate of nitrification.

[Treating high strength antibiotic wastewater by micro-aerobic hydrolysis and acidification process].

The effect of micro-aerobic hydrolysis and acidification to high strength antibiotic wastewater treatment is studied. The results demonstrate that micro oxygen enhanced the physiological metabolizability of facultative hydrolytic and acidogenic bacteria, and aerating stirring improved the hydraulic condition. Degree of acidification (AD) and volatile fatty acid (VFA) in the effluent reached 58.64% and 4825 mg/L with the shortest HRT 10 h and the maximal OLR 20 kg/(m3 x d), respectively. Wastewater biodegradability was improved greatly and rising BOD5/COD was about 17%, which offered good substrate for post aerobic treatment. The effluent quality was relative stable with the fluctuant influent, and COD and SS were 7000-8000 mg/L and 150-300 mg/L, respectively, while the removal efficiencies of COD and SS were 15%-30% and 90%-95%. The changement of VFA lagged behind that of AD in the effluent, and AD would represent the effect of hydrolysis and acidification process more properly. The sludge bed in the bottom of the reactor was the main reaction field for VFA production, and the height of the reactor for stable VFA production increased with the increase of OLR. The filling field mainly aimed to entrap SS in the effluent and benefited little to VFA production. Sludge in the reactor was mainly little sludge particles with the size of 0.5-1.0 mm and flocculent sludge.