Hongjian Lin

Prediction of Enological Parameters and Discrimination of Rice Wine Age Using Least-Squares Support Vector Machines and Near Infrared Spectroscopy

The use of least-squares support vector machines (LS-SVM) combined with near-infrared (NIR) spectra for prediction of enological parameters and discrimination of rice wine age is proposed. The scores of the first ten principal components (PCs) derived from PC analysis (PCA) and radial basis function (RBF) were used as input feature subset and kernel function of LS-SVM models, respectively. The optimal parameters, the relative weight of the regression error gamma and the kernel parameter sigma 2, were found from grid search and leave-one-out cross-validation. As compared to partial least-squares (PLS) regression, the performance of LS-SVM was slightly better, with higher determination coefficients for validation ( Rval2) and lower root-mean-square error of validation (RMSEP) for alcohol content, titratable acidity, and pH, respectively. When used to discriminate rice wine age, LS-SVM gave better results than discriminant analysis (DA). On the basis of the results, it was concluded that LS-SVM together with NIR spectroscopy was a reliable and accurate method for rice wine quality estimation.

Optimization of continuous hydrogen production from co-fermenting molasses with liquid swine manure in an anaerobic sequencing batch reactor.

This study investigated and optimized the operational conditions for continuous hydrogen production from sugar beet molasses, co-fermented with liquid swine manure in an anaerobic sequencing batch reactor. Results indicated that pH, HRT and total solids content in the swine manure (TS) had significant impact on all the responses such as biogas production rate (BPR), hydrogen content (HC), hydrogen production rate (HPR), and hydrogen yield (HY), although the highest level of each response was achieved at different combination of the three variables. The maximum BPR, HC, HPR and HY of 32.21 L/d, 30.51%, 2.23 L/d/L and 1.57 mol-H2/mol-sugar were estimated at the optimal pH, HRT, and TS of 5.55, 15.78 h, and 0.71% for BPR; 5.22, 12.04, and 0.69 for HC; 5.32, 15.62, and 0.78% for HPR; and 5.36, 17.56, and 0.74% for HY, respectively. Good linear relationships of the predicted and tested results for all the parameters were observed.

Phosphorus removal and recovery from dairy manure by electrocoagulation

Livestock manure waste, containing high level of phosphorus (P) will impair water environment if it is directly discharged to water body or improperly land applied. P recovery from animal manure not only addresses its environmental concerns, also provides a value added product as a fertilizer for better managing P. Electrocoagulation (EC) is proved to be an efficient approach that can be applied in the municipal and industrial wastewater for P removal and recovery; however, its application in the livestock manure management is less researched, especially with different selection of the electrode materials. In this study, EC process was evaluated on P removal and recovery from dairy manure. Four commonly seen electrodes, including Al, stainless steel, low carbon steel and cast iron, were compared. The results showed low carbon steel achieved the most efficient P removal (96.7%). The average particle size of manure solids was increased from 32.2 to 126.9 μm. The simulation experiment suggested that iron release and hydrolysis, which then worked as coagulants, is the major mechanism for P removal. EC by low carbon steel is an effective method for P separation from liquid phase of dairy manure to solid phase.

Pilot-scale field study for ammonia removal from lagoon biogas using an acid wet scrubber.

The anaerobic activities in swine slurry storage and treatment generate biogas containing gaseous ammonia component which is a chemical agent that can cause adverse environmental impacts when released to the atmosphere. The aim of this pilot plant study was to remove ammonia from biogas generated in a covered lagoon, using a sulfuric acid wet scrubber. The data showed that, on average, the biogas contained 43.7 ppm of ammonia and its concentration was found to be exponentially related to the air temperature inside the lagoon. When the air temperature rose to 35°C and the biogas ammonia concentration reached 90 ppm, the mass transfer of ammonia/ammonium from the deeper liquid body to the interface between the air and liquid became a limiting factor. The biogas velocity was critical in affecting ammonia removal efficiency of the wet scrubber. A biogas flow velocity of 8 to 12 mm s−1 was recommended to achieve a removal efficiency of greater than 60%. Stepwise regression revealed that the biogas velocity and air temperature, not the inlet ammonia concentration in biogas, affected the ammonia removal efficiency. Overall, when 73 g L−1 (or 0.75 M) sulfuric acid solution was used as the scrubber solution, removal efficiencies varied from 0% to 100% with an average of 55% over a 40‐d measurement period. Mass balance calculation based on ammonium–nitrogen concentration in final scrubber liquid showed that about 21.3 g of ammonia was collected from a total volume of 1169 m3 of biogas, while the scrubber solution should still maintain its ammonia absorbing ability until its concentration reaches up to 1 M. These results showed promising use of sulfuric acid wet scrubber for ammonia removal in the digester biogas.

Electricity generation and nutrients removal from high-strength liquid manure by air-cathode microbial fuel cells

ABSTRACT Air-cathode microbial fuel cells (MFCs) are widely tested to recover electrical energy from waste streams containing organic matter. When high-strength wastewater, such as liquid animal manure, is used as a medium, inhibition on anode and cathode catalysts potentially impairs the effectiveness of MFC performance in power generation and pollutant removal. This study evaluated possible inhibitive effects of liquid swine manure components on MFC power generation, improved liquid manure-fed MFCs performance by pretreatment (dilution and selective adsorption), and modeled the kinetics of organic matter and nutrients removal kinetics. Parameters monitored included pH, conductivity, chemical oxygen demand (COD), volatile fatty acids (VFAs), total ammoniacal nitrogen (TAN), nitrite, nitrate, and phosphate concentrations. The removals of VFA and TAN were efficient, indicated by the short half-life times of 4.99 and 7.84 d, respectively. The mechanism for phosphate decrease was principally the salt precipitation on cathode, but the removal was incomplete after 42-d operation. MFC with an external resistor of 2.2 kΩ and fed with swine wastewater generated relatively small power (28.2 μW), energy efficiency (0.37%) and Coulombic efficiency (1.5%). Dilution of swine wastewater dramatically improved the power generation as the inhibitory effect was decreased. Zeolite and granular activated carbon were effective in the selective adsorption of ammonia or organic matter in swine wastewater, and so substantially improved the power generation, energy efficiency, and Coulombic efficiency. A smaller external resistor in the circuit was also observed to promote the organic matter degradation and thus to shorten the treatment time. Overall, air-cathode MFCs are promising for generating electrical power from livestock wastewater and meanwhile reducing the level of organic matter and nutrients.

In-depth observations of fermentative hydrogen production from liquid swine manure using an anaerobic sequencing batch reactor

Abstract In this study, experiments were designed to reveal in-depth information of the effect of pH and hydraulic retention time (HRT) on biohydrogen fermentation from liquid swine manure supplemented with glucose using an Anaerobic Sequencing Batch Reactor (ASBR) System. Five values of HRT (8, 12, 16, 20, and 24 h) were first tested and the best HRT determined was further studied at five pH levels (4.4, 4.7, 5.0, 5.3, and 5.6). The results showed that for HRT 24 h, there was a dividing H 2 content (around 37%) related to the total biogas production rate for the ASBR System running at pH 5.0. When the H 2 content went beyond 37%, an appreciable decline in biogas production rate was observed, implying that there might exist an H 2 content limit in the biogas. For other HRTs (8 through 20 h), an average H 2 content of 42% could be achieved. In the second experiment (HRT 12 h), the highest H 2 content (35%) in the biogas was found to be associated with pH 5.0. The upswing of pH from 5.0 to 5.6 had a significantly more impact on biogas H 2 content than the downswing of pH from 5.0 to 4.3. The results also indicated good linear relationships of biogas and H 2 production rates with HRT ( r =0.9971 and 0.9967, respectively). Since the optimal ASBR operating conditions were different for the biogas/H 2 production rates and the H 2 yield, a compromised combination of the running parameters was determined to be HRT 12 h and pH 5.0 in order to achieve good biogas/H 2 productions.

Kinetics, equilibrium, and thermodynamics of ammonium sorption from swine manure by natural chabazite

ABSTRACT Sorption kinetics and equilibria were evaluated in shaken-batch mode for ammonium separation from liquid swine manure through chabazite, a type of Ca-dominated natural zeolite. A set of kinetic and isothermal models were assessed. Total ammoniacal nitrogen sorption capacity was 11.6 mg/g-chabazite, and the maximum sorption capacity at room temperature was 34.2 mg/g-chabazite. Thermodynamic parameters indicated the spontaneity and exothermic nature of the sorption. Chabazite sorption decreased soluble phosphorus, possibly by forming insoluble calcium phosphate. This study demonstrated that chabazite sorbent was effective for ammonium separation from liquid swine manure, and the resulting sorbent may be used as slow-release nitrogen fertilizer.

Influence of Seeds Moisture on in situ Alkaline Transesterification of Canola Seeds for Biodiesel Production

In situ alkaline transesterification is reported to be an efficient method of biodiesel (methyl ester) production from several oilseed crops. Seed moisture content has a significant influence on methyl ester yields from biodiesel made in situ. Biodiesel quality properties are closely associated with the parent feed stock, and methyl esters derived from conventional transesterified canola oil have improved cold flow properties when compared to other oilseed crops. This study evaluated canola in situ alkaline transesterification and examined the impact of seed moisture content on methyl ester yield. Biodiesel quality parameters including oxidative stability, moisture content, kinematic viscosity, free fatty acids and total glycerin were evaluated between biodiesel derived from conventional and in situ methods.

Near-infrared transmittance spectroscopy for nondestructive determination of soluble solids content and pH in tomato juice

The potential of near-infrared (NIR) transmittance spectroscopy to nondestructively detect soluble solids contents (SSC) and pH in tomato juices was investigated. A total of 200 tomato juice samples were used for NIR spectroscopy analysis at 800-2400 nm using FT-NIR spectrometer. Multiplicative signal correcton (MSC), the first and second derivative were applied for preprocessing spectral data. The relationship between SSC, pH and FT-NIR spectra of tomato juice was analyzed via partial least-squares (PLS) regression, respectively. PLS regression models for SSC and pH in tomato juices show the high accuracy. The correlation coefficient (r), root mean square error of calibration (RMSEC) and root mean square error of validation (RMSEP), root mean square error of cross-validation (RMSECV) for SSC were 0.91582, 0.0703, 0.150 and 0.138, respectively, whereas those values for pH were 0.8997, 0.0333, 0.0316 and 0.0489, respectively. It is concluded that the NIR transmittance spectroscopy is promising for the fast and nondestructive detection of chemical components in tomato juices.

Effect of Trace Contaminants on Cold Soak Filterability of Canola Biodiesel

ASTM D 7501-09b, a cold soak filtration test (CSFT) was included in B100 specifications of ASTM D 6751-09, and brought new challenges to biodiesel producers and researchers investigating B100 quality. For a plant breeding program evaluating canola biodiesel quality traits, rapid assessment of biodiesel quality is important. Unfortunately, a limited amount of canola seed is available and obtaining the required volume of biodiesel (300 mL) for evaluating cold soak filterability is challenging. In order to develop a high throughput screening method of canola breeding lines for B100, assessing the cold soak filterability with reduced volumes of biodiesel is necessary. The primary objective of this study was to evaluate the impact of saturated monoglycerides, glycerin, and soap on cold soak filterability. The influence of saturated monoglycerides (0.04% to 0.46% w/w) on biodiesel precipitate formation was also evaluated. A regression model was generated to predict the filterability of biodiesel against the concentrations of trace contaminants. These experiments explored the possibility of using small scale biodiesel batches for scaling down the CSFT for canola breeding program for biodiesel production.