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1.
A crab processing waste/wood shaving mixture was composted in-vessel with four intermittent aeration strategies. The composting process was monitored to assess the efficacy of the aeration methods. Temperature, moisture content and volatile solids of the compost were monitored along with the interstitial oxygen concentration. There was no significant difference in temperature profiles between constant frequency aeration and temperature feedback controlled aeration methods. An increased frequency of aeration resulted in significantly more drying than the less frequent aeration using the same total air volume. Results indicated that air volume could be reduced after the first five days of composting, and the in-vessel composting retention time could be reduced to 15 to 17 days for odor and vermin/vector problems prevention.  相似文献   

2.
反应器堆肥技术作为一种新型快速堆肥方式逐渐被人们所认可,该技术包括反应器堆肥处理和陈化两个阶段,但反应器堆肥时长和通气方式等工艺参数对堆肥全过程的影响尚不清楚。因此,本研究立足生产中的实际问题,利用12 m3立式堆肥反应器,开展了反应器堆肥工艺优化调控试验,以鸡粪和锯末为原料,分别研究了连续供气和间歇供气(风机开3 min,关7 min)两种供气方式下,反应器处理周期对堆肥有机质降解率、产品含水率、氮素损失和运行成本的影响。研究结果表明:反应器堆肥10 d比2 d的处理物料有机质降解率分别增加60.7%(间歇)和66.2%(连续),产品含水率分别降低41.2%(间歇)和40.7%(连续)。反应器堆肥阶段是物料降解的主要阶段,利用反应器堆肥的时长越长,堆肥产品生产时间越短;但运行成本的增加也对反应器堆肥时长造成了限制,同时增加反应器堆肥时长也会增加堆肥物料的氮素损失,其中连续供气反应器堆肥10 d比2 d氮素损失增加17.5%。连续供气方式可提高堆肥效率,较间歇供气处理堆肥周期平均缩短32.1%,产品全氮含量平均提高7.4%,虽然反应器堆肥阶段每日能耗较间歇供气高20.2%,但堆肥周期的缩短使全程连续供气平均运行成本降低16.5%。其中,连续供气下反应器中处理6 d、8 d和10 d,堆肥产品理化性质无显著差异。综合考虑堆肥效率、产品和经济,本试验建议选择“连续供气方式+反应器内堆肥8 d”处理,既可提高反应器堆肥处理效率,在实际生产中又具有较高的经济效益潜力。  相似文献   

3.
针对堆肥化过程中常伴有少量CH4等温室气体排放造成环境污染等问题,采用密闭堆肥化装置,进行了不同碳氮比和通气条件下,堆肥过程中的气体释放规律、影响因子及其对堆肥理化性质的影响研究。结果表明,C/N=25、30堆肥处理的有机物降解率高于低碳氮比处理;全氮含量随着有机物的降解而浓缩,随着堆肥的进行而不断提高,到堆肥结束时,C/N=15、20、25和30处理的全氮含量分别为23.5、24、27.8 g.kg-1和28.4 g.kg-1;堆肥过程中,C/N=15、20、25和30的堆肥处理CH4累积排放为0.67、0.95、2.25g.kg-1和1.80 g.kg-1,损失比例占初始碳物质的0.39%、0.5%、1.24%和0.92%,并且CH4气体的排放主要集中在高温前期,高温期越长,排放的温室气体越多。高温期适当增大通气量,对于控制堆肥温度和减少温室气体生成有双重作用。  相似文献   

4.
While composting transforms manure wastes into useful fertilizer, it also produces odors during the decomposition process. Biofiltration is a desirable method to control composting odor. This study was conducted to investigate the efficiency of using compost as a biofilter. A mixture of cattle manure and fresh compost was composted in a bin equipped with a suction-type blower. The exhaust gas was filtered through the biofilter of fresh compost. The composting temperature affected the ammonia emission. When the composting temperature was relatively high, the highest ammonia emission appeared in two experiments. The biofiltering properties were investigated according to flow rates and filter depths for two different types of fresh composts (experiment I and II). At the flow rate of 30 L/min, ammonia removal rate was 80.5% for biofilter A(detention time 56.5 s) and 99.9% for biofilter B (detention time 113 s). At the flow rate of 50 L/min, the ammonia removal rate was 82.5% for biofilter A (detention time 33.9 s) and 97.4% for biofilter B (detention time 67.8). The fresh compost could be used as a biofilter medium for odor control during composting process. The moisture content(MC) of the biofilter material increased by absorbing moisture from the exhaust gas, while the pH was decreased due to the degradation of nitrogenous compounds. As the moisture in the exhaust gas increased the MC of the biofilter, there was no need to spray water to the biofilter medium to control moisture content. While the total nitrogen(T-N) of the biofilter increased by absorbing ammonia, the total carbon (T-C) remained unchanged resulting in decrease of the C/N ratio.  相似文献   

5.
碳氮比对鸡粪堆肥腐熟度和臭气排放的影响   总被引:4,自引:2,他引:2  
为确定鸡粪堆肥最优碳氮比(C/N比),该研究以新鲜鸡粪为堆肥原料,添加玉米秸秆调节初始C/N比为14、18和22进行好氧堆肥,研究不同C/N比对鸡粪堆肥腐熟度和臭气排放(NH3和H2S)的影响。结果表明:C/N比为14的处理堆肥产品未腐熟,C/N比为18和22的处理均达到腐熟。C/N比为18的处理NH3累积排放量和总氮(TN)损失率最高;C/N比为18~22时,C/N比越高,NH3累积排放量和TN损失率越低。C/N比为14的处理H2S累积排放量和总硫(TS)损失率最高;C/N比为18和22的两个处理,H2S累积排放量显著降低,且无显著差异。此外,C/N比为18处理的微生物群落多样性在整个堆肥过程中显著高于C/N比为14和22处理。堆肥的理化指标、臭气排放与微生物群落之间的相关性分析表明,高温、高pH和缺氧环境会增加Firmicutes丰度,进而促进NH3和H2S的排放,相反地,低温、低pH和氧气充足的环境更有利于Actinobacteria增殖,有利于减少NH3和H2S的排放。综合考虑堆肥产品腐熟度和臭气减排效果,建议低C/N比鸡粪堆肥的初始C/N比为18~22。当秸秆资源不足时,建议初始C/N比为18;秸秆资源充足时,建议初始C/N比为22。  相似文献   

6.
易降解有机质含量对黄瓜秧堆肥腐熟和氮损失的影响   总被引:5,自引:4,他引:5  
蔬菜废弃物无害化处理,尤其对于集约化蔬菜产地,缺乏适用技术,易污染环境,浪费资源,甚至造成后续安全隐患。为实现蔬菜废弃物的安全高效转化,该试验以黄瓜秧为堆肥主原料,以玉米秸秆、淀粉和尿素为调理剂,在控制混合堆肥物料初始碳氮比为25,物料水分质量分数为60%,总物料质量相同的条件下,分析易降解有机质(除木质纤维素之外的有机质)比例对堆肥腐熟进程和氮素损失的影响。试验设置添加易降解有机质的质量分数分别为27%(T1)、36%(T2)、45%(T3)、51%(T4)4个处理,利用自制密闭式堆肥反应器研究了随堆肥进行,不同处理温度、物料损失、有机质降解和二氧化碳释放、p H值、电导率(electrical conductivity,EC)、发芽率指数(germination index,GI)的变化情况,并同时分析了氨气挥发速率、累积排放量和氮素损失率等。研究结果显示:随着初始混合物料中易降解有机质的增加,堆体的最高温度呈现出先升高后降低的趋势,但根据物料的p H值、EC和GI值判断,易降解有机质比例过高会影响堆肥的腐熟过程,其比例不宜超过45%,其中T3的最高温度最高,高达71.4℃,且有机质减少量和CO2累积排放量最高,表明T3最利于堆肥的起爆反应和无害化目标的实现;然而,易降解有机质的增加会伴随氮素损失,尤其是氨气挥发损失量的增加,其中T3氨气损失累积量最大(380.29 mg),T4的氮素损失率最高(36.01%),即物料中的木质纤维素有利于减少氮素的损失。综上,物料中易降解有机质质量分数为45%最利于堆肥的高温实现,同时对腐熟的影响较小,但氮素损失率高,因此实际生产中可额外添加木质纤维素类膨胀剂,改良物料的物理结构和理化特点,从而在实现高温的基础上减少氮素的损失。  相似文献   

7.
城市污泥与调理剂混合堆肥过程中有机质组分的变化   总被引:5,自引:4,他引:1  
【目的】研究城市污泥堆肥过程中各项有机质组分及碳、 氮在堆肥过程中的形成与转化,以期改善堆肥的生物有效性,促进其土地利用。【方法】在工厂规模化下,以城市污泥、 蘑菇渣锯末以及返混料按照6∶3∶1的质量比混合形成堆肥物料,辅以强制通风措施和翻抛,进行为期18 d的高温堆肥试验。堆肥期间定期采样,测定指标包括温度、 C/N值、 pH、 含水率、 有机质降解率、 水溶性组分、 半纤维素、 纤维素和木质素,研究堆肥期间不同阶段堆肥物料中有机质组分的动态变化。【结果】堆体温度随着发酵时间的延长呈现先升高后降低的趋势,最高温度达到71.3℃; 含水率由60.7%降低到51.4%,pH呈现先升高后降低的趋势,总体处于6.0~7.5之间; 总有机碳含量持续下降,氮素含量表现为高温期持续下降随后呈上升的趋势; 初始阶段,堆肥物料中四种成分含量分布为: 水溶性组分纤维素半纤维素木质素,至堆肥结束变化为: 纤维素水溶性组分木质素半纤维素,经过堆肥之后水溶性组分及半纤维素含量分别由39.5%和20.1%下降为27.9%和14.4%,纤维素含量由初始的21.8%上升至29.5%,木质素含量相对稳定不变。物料经过堆肥化处理后达到腐熟标准,水溶性组分和半纤维素含量分别降低了38.6%和38.8%,纤维素和木质素含量在高温期分别降解了11.7%和18.5%; 物料总量降低了9.8%。水溶性组分的主要降解阶段为高温期,期间降解部分占总降解量的65.5%; 半纤维素的主要降解阶段为稳定期,稳定期降解部分占总降解量的69.1%,且有继续降解的趋势; 纤维素和木质素仅在高温期有少量降解; 氮素则表现为高温期铵态氮的损失及稳定期硝态氮的积累。【结论】堆肥化处理在实现污泥减量化基础上,污泥中有机质得到了稳定化,有利于城市污泥的土地利用。  相似文献   

8.
膨松剂对厨余垃圾堆肥CH4、N2O和NH3排放的影响   总被引:6,自引:5,他引:1  
厨余垃圾有别于混合生活垃圾,具有高有机质含量和高含水率等特点,单独堆肥会产生大量CH4、N2O、NH3和渗滤液,为减少厨余垃圾堆肥过程污染物的排放,该文以居民小区产生的经大类粗分后的厨余垃圾为研究对象,以菌糠为膨松剂,设置15%、25%、35% 3个添加质量比(湿基)的堆肥处理,以纯厨余垃圾单独堆肥为对照处理,研究菌糠作为膨松剂对厨余垃圾堆肥过程中CH4、N2O、NH3和渗滤液排放的影响及其最佳添加比例。结果表明,堆肥过程中,添加菌糠可以完全避免厨余垃圾堆肥过程中渗滤液的产生;堆肥结束时,添加15%和25%菌糠的处理堆肥达到腐熟标准,但添加35%的菌糠使堆肥高温期缩短,不利于有机质分解;与对照处理相比,添加15%、25%和35%比例的菌糠均可以减少堆肥过程中CH4和NH3的累计排放量,且减排量与添加比例正相关,但只有添加15%菌糠的堆肥处理明显降低了N2O的排放量;添加质量比为15%和25%菌糠的堆肥处理,CH4和N2O排放总量比厨余垃圾单独堆肥分别减少45.8%、19.6%,而添加质量比为35%的菌糠使CH4和N2O排放总量为厨余垃圾单独堆肥的1.14倍(每t物料,干基)。综上,菌糠作为食用菌种植废弃物,可用作厨余垃圾堆肥膨松剂,在适宜的添加比例条件下,能够在避免堆肥过程中渗滤液产生的同时,减少CH4、N2O和NH3的排放量。研究结果可为厨余垃圾堆肥过程温室气体减排、氮素损失控制和工艺改进提供理论依据和试验基础。  相似文献   

9.
The effects of using intermittent aeration during composting on ammonia emissions and dry matter loss were determined during composting of hog manure amended with sawdust. Composting trials lasted three weeks and used pilot-scale 200 liter vessels (four). The experimental design used replication of two treatments, continuous aeration (CA) and intermittent aeration (IA), in two series of experiments (total of eight tests). In the CA sequence, compost temperatures were controlled at 60°C using feedback control on high and low air flow fans while the IA sequence consisted of five minutes of air flow followed by 55 minutes of rest. Mixing ratios of hog manure to sawdust were 1:1.1 and 1:1.7 dry weight basis with resulting C:N ratios of 18.2 ± 1.2 and 23.7 ± 2.2 for the two series of tests. Airflow reduction was 63 percent for IA compared to CA. Percent nitrogen loss between treatments were moderately statistically different (α = 0.14) with average percent nitrogen loss at 29.7 percent for CA and 23.0 percent for IA. Nitrogen loss as ammonia-N was higher for CA than IA (25.9 versus 14.3) but was not statistically different. No significant differences existed in dry solids loss between treatments and the physical and chemical properties of the compost produced from IA were similar to that from CA for each series. Results showed that IA compared to CA may be a practical way to reduce nitrogen loss and ammonia emissions during composting of swine manure with sawdust.  相似文献   

10.
NH3和N2O等含氮气体的排放不仅对堆肥腐熟度和堆肥产品的品质产生影响,同时也与环境污染有直接关系。以鸡粪、秸秆和干草皮为堆肥原料,采用好氧堆肥的方法,探讨了不同通风速率对堆肥腐熟度及NH3和N2O等含氮气体排放变化的影响。结果表明,通风速率为0.01、0.1、0.2 m3.min^-1.m^-3的处理高温期持续时间分别为0、11、7 d;0.1 m3.min^-1.m^-3的堆肥积温为16 176.4℃.h,在各处理中为最高;到堆肥结束时,各处理的全碳降解率分别为9.87%、24.94%、19.01%,总氮增加率分别为19.67%、32.00%、12.14%,其中处理A2的有机质降解及总氮增加效果最好。对堆肥产物腐熟度的测试结果表明,除通风速率为0.01 m3.min^-1.m^-3不能达到堆肥腐熟外,其他两个处理均达到了要求。氨气累积释放量与通气速率有关,通气速率越大,越有利于氨气的挥发。低的通气量可能会促成N2O的生成,到堆肥结束时,3个处理的N2O平均排放率分别为6.2、2.37、1.5 mg.kg^-1.d^-1。  相似文献   

11.
醋糟条垛式堆肥发酵技术及效果   总被引:4,自引:1,他引:3  
为了探讨醋糟发酵过程中氮素形态变化对pH值的影响,采用向堆体添加水分的两阶段条垛式堆肥发酵方法,测定了两个阶段堆体中总氮、氨氮、硝氮的质量分数及堆体温度、有机质、pH值。试验结果表明:堆肥完成后堆体总氮、氨氮、硝氮相对质量分数均有所上升,堆体pH值由最初的4.3上升至最高7.94,最后又回落至6.3左右,有机质质量分数由最初的91.8%下降到了83.2%,发芽指数GI达到102.3%。研究表明:经两阶段堆肥发酵,醋糟堆体已完全腐熟。  相似文献   

12.
为探究锰矿物添加对微好氧堆肥过程腐熟、温室气体和臭气排放的影响,以由厨余垃圾、水稻秸秆、羊粪和尾菜组成的多元混合物料堆肥为研究对象,共设3个处理,采用间歇通风方式,将通风速率为0.14 L/(kg·min)设置为好氧堆肥对照(CK),速率为0.06 L/(kg·min)为微好氧处理(T1),添加二氧化锰(MnO2)的微好氧处理为T2。结果表明:多元废弃物好氧或微好氧堆肥在堆制70 d后均能腐熟,但T2处理腐熟度显著高于T1。微好氧处理T1、T2减少了26.47%~30.29%的NH3和33.19%~38.60%的N2O的排放,总温室效应减少了29.26%~31.38%。臭气的排放集中在前14 d,T1、T2处理的H2S和VOCs的释放量显著增加了320.35%~501.04%和39.82%~53.63%。因此,微好氧堆肥可达到减排目的,但却加剧臭气的排放;MnO2可提高促进堆肥腐熟,降低温室气体和臭气的排放。  相似文献   

13.
为了促进发酵床废弃垫料的循环利用,以猪菌渣发酵床垫料为原料,进行了堆肥腐解试验,测定了菌渣垫料堆肥的理化性状和重金属含量,开展了菌渣垫料堆肥种植甘蓝试验。结果表明,菌渣垫料堆肥中有机质、pH值、重金属含量均达到了有机肥料标准(NY 525-2012)要求,全氮、全磷、全钾的总养分含量为4.48%,略低于标准要求。用作底肥种植甘蓝,每公顷施用菌渣垫料堆肥6 000 kg时,甘蓝产量与施用相同用量商品有机肥无显著差异,随着菌渣堆肥施用量的增加,甘蓝产量呈增加趋势。  相似文献   

14.
In this study, medlar pruning waste (MPW) was composted with and without cattle manure (CM). Two piles were prepared: one contained only MPW (pile 1) and one contained MPW augmented with CM (pile 2). Both piles were composted in an enclosed composting vessel with passive aeration and aeration by turning. During the composting process, temperature, pH, electrical conductivity (EC), organic matter (OM), OM losses, total organic carbon (Corg), total nitrogen (NT), Corg/NT ratio, and germination index (GI) were measured. Pile 2 produced a faster increase of the temperature and had a longer thermophilic phase than pile 1. However, the rate of OM degradation was faster in pile 1 than in the pile containing CM (pile 2). The addition of CM also resulted in an increased pH and salt content. In both piles, C/N ratio decreased throughout the process, presumably as a result of the faster organic carbon degradation compared to N mineralization. However, only pile 2 had a final C/N ratio <20, the limit accepted for compost by the Spanish legislation on fertilizer. Also, both composts had GI > 50 percent, indicating an absence of phytotoxicity.  相似文献   

15.
碳源调理剂对黄瓜秧堆肥进程和碳氮养分损失的影响   总被引:4,自引:3,他引:4  
由于中国蔬菜产地的黄瓜秧无害化处理与循环利用缺乏针对性的使用技术,这类废弃资源多成为当地的环境污染源。该文以黄瓜秧为原料(空白对照,CK)进行高温好氧堆肥,并在此基础上设置2组处理,即把玉米秸秆(CS)和木本泥炭(WP)作为辅助碳源调理剂,按照C/N比为25添加到物料中。通过对比分析不同处理的CO2和氨气的排放速率和累积量、物料损失率、有机质含量、p H值、电导率(EC)、发芽指数等指标,研究外加碳源对黄瓜秧堆肥过程和碳氮氧分损失的影响,以期实现对黄瓜秧堆肥化进程进行工艺优化,并降低碳氮元素以气态形式的损失,进而减少温室气体排放。结果表明:玉米秸秆和木本泥炭作为外加碳源调理剂,可以减少物料损失量,加速堆肥腐熟进程,其中尤以玉米秸秆效果更佳。但是,玉米秸秆的添加会增加整个堆肥过程中有机质的降解和CO2的排放强度,提高累积排放量(100g/kg),而木本泥炭会减少有机质的降解总量和CO2的累积排放量(77g/kg);玉米秸秆和木本泥炭都有利于控制堆肥过程中氨气的排放,且作用时间和机理不同。综合考虑堆肥进程和气体损失,木本泥炭作为碳源调理剂的改良效果更优于秸秆,应进一步研究两者联合使用的效果。  相似文献   

16.
An integrated model was developed to simulate the temporal change and spatial variation of temperature and spatial distribution of TM (total mass) and MC (moisture content) of the final compost for composting process of sewage sludge. The model included biodegradation kinetics of organic matter and balance equations of energy and mass. First-order assumption was applied to describe the biodegradation process with correction functions of temperature, oxygen, MC, and FAS (free air space). The transfer process was considered in balance equations of energy and mass. A finite difference method was used to solve the model. Two trials of 0.21 m3 were run to estimate parameters and evaluate the simulation. The model could predict TM and VS (volatile solid) of the final compost well, temporal trend of oxygen concentration and water removal, and also a good fitting of the temporal and spatial change of temperature. Hrx (reaction enthalpy of biodegradable volatile solid) and ηBVS (mass fraction of biodegradable volatile solid) were considered the most sensitive parameters based on the sensitivity analysis. Future research was suggested to focus on reasonable humidity assumption, measuring accurate value of thermodynamics and kinetics parameters of sewage sludge, and simulating the composting process with different aeration modes and turning of the pile.  相似文献   

17.
To calculate the correct nitrogen fertilizer rate for crops and the possibility of using municipal solid waste (MSW) compost as an organic amendment, nitrogen mineralization rates were studied by laboratory incubation and field measurements in a soil in central Spain. Nitrogen mineralization rates were studied in a 250-day laboratory soil incubation with two treatments: with and without compost, incubated at 28°C and a moisture content of 70% of field capacity. Three phases are described: (1) no increase in the mineral nitrogen content, (2) a linear increase in the mineral N fraction and, finally, (3) a linear, parallel increase in both mineral N and easily mineralizable organic N fractions. Incubation data were fitted to three different equations. The exponential model proposed by Stanford and Smith (1972) was selected to predict field N mineralization rates. The field experiment was performed using a crop of maize with three treatments: compost applied in February (before sowing), compost applied during sowing and a control (without compost application): sampling was carried out over 14 months. Soil water content was measured periodically. Soil with compost applied in February showed 1.9 and 1.4 times more available nitrogen than soil without compost and compost at sowing, respectively, for the month of maximum accumulation. These results suggest that compost amendments must be applied before sowing. Compost applications were shown to supply the available nitrogen for spring crops. A simulation model showed satisfactory agreement with field data, after correction for soil temperature and water content. Received: 22 July 1996  相似文献   

18.
The release of ammonia nitrogen during composting of sewage sludge mixed with a lignocellulosic bulking agent leads to a reduction in the agronomic value of the final compost and to harmful effects on the environment. We propose adding a cheap salt FeCl3 which can be used without special precaution to reduce ammonia losses by decreasing pH conditions. An in-vessel co-composting experiment was conducted in a large reactor (100 L) in which FeCl3 was added to sludge mixed with a bulking agent (pine shavings and sawdust) and compared with a control mixture without FeCl3. Temperature, oxygen consumption and pH were monitored throughout the composting of both mixtures. The final balance of organic matter, organic and inorganic nitrogen permitted to conclude that the addition of FeCl3 reduced nitrogen loss (by a factor of 2.4 in relation to the control) and increased mineralisation of the organic nitrogen by 1.6.  相似文献   

19.
The quality of compost made from the organic fraction of municipal organic waste (MOW), in terms of organic matter and nutrient concentrations, is inferior to that of compost from other feedstocks. The aim of this work was to improve the quality of MOW compost by means of cocomposting with biosolids (at ratios of 1:1, 2:1, and 3:1 MOW/biosolids) and vermicomposting. Vermicomposting (ground beds with worms) treatments were prepared from traditional pile material after 40 composting days; ground beds without worms were also included. Several parameters, including pH, electrical conductivity, carbon dioxide production, organic matter, total nitrogen, water-soluble carbon, nitrate, ammonium, and extractable phosphorus, were measured throughout the process. Organic matter in the products at 120 days ranged between 39 and 45%, whereas total nitrogen was between 1.7 and 2%. Considering these parameters, the quality of MOW and biosolids cocompost was better than that of MOW composted alone in a previous study (18% organic matter and 0.7% total nitrogen concentration). Extractable phosphorus was also greatly increased from 128 mg/kg in MOW compost to 542–722 mg/kg in the cocompost. Of the three MOW/biosolids ratios employed, only the 2:1 and 3:1 mixtures were adequate for composting and produced similar product qualities. However, the 2:1 mixture required more turnings and exhibited higher N losses. The improvement of quality by vermicomposting was limited. Compared to traditional piles, it did not affect concentrations of organic matter or total nitrogen. The direct action of worms, measured by comparing ground beds with and without worms, increased nitrate concentrations for mixtures 2:1 and 3:1 and extractable phosphorus concentrations for mixture 3:1.  相似文献   

20.
【目的】利用电子鼻和分光测色仪建立一套快速检测茶树叶片氮含量的无损伤检测方法。【方法】供试样品为茶树顶芽向下第3~4片无损伤叶片。在预实验中优化了气体收集瓶体积、顶空预热温度和顶空时间等参数。采用电子鼻自带Winmuster软件将经过优化后的传感器响应特征值进行主成分分析(principal component analysis,PCA)、线性判别法分析(linear discriminant analysis,LDA)和负荷加载分析(loadings analysis,LA),筛选出灵敏性最好的传感器。同时用分光色差仪对茶树叶片色度值进行测定。样品的测量部位是叶肉区,每组20次重复。色度值主要包括L (表示黑白或者亮暗)、a (表示红绿)、b (表示黄蓝)值。采用Origin 8.0软件对测色仪L、a、b值分别进行一元线性回归分析。利用SPSS 16.0软件采用LSD法进行单因素方差分析(one-way Anova),并进行t检验。对分光测色仪中色差指标进行筛选,以获得相关系数最高的参数。采用凯氏定氮法测定茶叶总氮含量。正式试验第二步是以不同氮含量下的电子鼻和分光测色检测数据为基础,分别建立气味、颜色、气味结合颜色的3种氮含量预测模型,并进行比较分析。【结果】通过预备试验,建立了气体收集器体积为50 mL、顶空预热温度为30℃、顶空时间为30 min的电子鼻检测体系。正式试验第一步确定了以对氮氧化合物灵敏(S2),对甲烷灵敏(S6),对无机硫化物灵敏(S7),对醇类、醛类、酮类物质灵敏(S8),对有机硫化物灵敏(S9)的传感器为主要传感器。根据L、a、b表色系统,b值与叶片缺氮程度呈线性相关。正式试验第二步利用气味、颜色、气味结合颜色建立的3个氮含量预测模型都具有可行性,其中气味结合颜色建立的预测模型准确率最高,达到90%。【结论】用气味结合颜色的预测模型预测茶树叶片氮含量准确度较高,可在实际工作中进行运用。  相似文献   

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