稻壳资源化新工艺的研究

根据纤维素、半纤维素、木质素在高温高压水中分解速度相差很大的特点，提出了一条稻壳资源化的新工艺，以便减少废弃物、最大限度地得到糖类化合物。新工艺主要包括连续水蒸汽蒸煮爆碎处理、连续近临界水处理和燃烧三步。研究了连续近临界水处理过程中温度和停留时间对液相分解产物的收率和残渣组成的影响，并得到了较优的操作条件。通过对新工艺中固形物组成变化的研究得知：水蒸汽蒸煮爆碎处理过程主要分解半纤维素，而连续近临界水处理同时水解纤维素和含硅化合物。新工艺可将约80%的碳源转化为水溶性物质，其中多聚糖和单糖的收率可达40%（wt）以上。新工艺为稻壳的全面综合利用提供了一条新途径。     

近临界水中大豆油无催化水解反应动力学研究

为系统研究油脂在近临界水中的水解动力学机理，系统地测定了压力10 MPa下，温度180～240℃范围内大豆油在近临界水中水解反应的动力学数据。试验结果表明，近临界水中大豆油水解反应是一个典型的自催化反应，在无任何外加催化剂的情况下大豆油可以在近临界水中顺利进行水解反应生成脂肪酸和甘油。温度对水解反应影响很大，随温度升高，水解反应速率迅速增大。采用二级自催化反应动力学模型对动力学数据进行了拟合，得到大豆油在近临界水中水解反应的活化能为43.2 kJ/mol。     

红酵母发酵豆腐渣产类胡萝卜素工艺优化

豆腐渣虽含有多种营养成分,但大约50%的干物质是难以消化的纤维素及半纤维素,直接用作饲料,饲喂效果并不理想。为了提高豆腐渣的饲用价值,进行了红酵母发酵豆腐渣产类胡萝卜素工艺优化研究。首先,在单因素试验基础上进行正交试验的结果显示,优化的豆腐渣酸解产还原糖工艺参数为:盐酸浓度1.0mol/L,料液比(g/mL)1∶10,酸解温度100℃,酸解时间3.0h,该条件下还原糖得率达29.06%±0.07%。然后,选用嗜还原糖红酵母发酵富含还原糖的豆腐渣酸解产物,以产生具有抗氧化、增强机体免疫等多种生物学功能的类胡萝卜素。通过单因素试验、Plackett-Burman试验回归分析、Box-Behnken试验及响应面分析,获得优化的发酵工艺参数:发酵底物pH值6.0,装液量80 mL/(500 mL),接种龄48 h,接种量11%(种子液浓度为8.5×10~9 CFU/mL),转速60 r/min,发酵温度31℃,发酵时间128 h;该条件下类胡萝卜素产量达(2.65±0.02)mg/L,比工艺优化前产量提高了67.7%,研究结果可为利用廉价豆腐渣开发高附加值类胡萝卜素功能饲料提供参考。     

粗糙元覆盖对土壤风蚀的控制作用

应用湍流边界层中粗糙壁面的阻力分解规律研究土壤风蚀中的临界侵蚀风速、输沙率和风蚀率,建立了一个揭示地表粗糙元对土壤风蚀控制作用的理论模型。该模型给出了临界侵蚀风速与盖度之间的指数关系,临界侵蚀风速与农田茬高之间的指数关系,以及反映输沙率(或风蚀率)与盖度(或茬高)、风速之间依赖关系的理论公式。然后应用天然地表风蚀和农田风蚀的多家实验数据,对这些理论公式进行了广泛地检验和评价,发现具有很好的普适性。     

黄土高原多沙粗沙区侵蚀产沙的临界问题

黄土高原多沙粗沙区高强度产沙是自然因素和人文因素综合作用的结果。该产沙过程对其影响要素存在着多个维度的临界响应。在对多沙粗沙区侵蚀产沙影响要素进行识别的基础上，比较系统地阐述了该地区侵蚀产沙存在的自然临界和社会经济临界问题及其产生的内在机理，以便为该地区的水土流失治理和生态环境建设提供一定的理论和调控依据。     

FAO56计算水分胁迫系数的方法在田间水量平衡分析中的应用

从作物水分胁迫系数的基本概念和FAO56的相关公式出发，考虑土壤临界含水量的时间变化，推导出了一个水分胁迫系数计算公式，该公式比较全面地表达了土壤供水能力、作物潜在腾发量与作物所受水分胁迫之间的关系。将该公式和另一幂函数公式应用于山西潇河冬小麦田间水量平衡分析，两者对土壤水分的动态模拟都达到了较高的精度，水量平衡计算结果也比较合理，模型的参数基本一致。与幂函数公式建立的模型相比，新公式建立的田间水量平衡模型具有待定参数少、求解结果稳定、易于收敛的优点，同时还能得到0～1 m土壤临界含水量变化曲线。该曲线反映了作物在土壤水分消退的过程中遭受不同程度水分胁迫的可能性大小，并得出土壤临界含水量在冬小麦生长前期较小，中期最大，后期较大。在返青～收获期，0～1 m深土壤临界含水量最大为290 mm，最小为215 mm，平均值为247 mm。这些结论对于农业用水管理具有一定的参考价值。     

甲鱼养殖废水用于土培和基质培的应用研究

集约化水产养殖技术近２０年来在国内外得到迅速发展,集约化养殖是高密度的控温养殖,在此条件下,喂食含高蛋白的配合饲料,鱼类的排泄物和残铒沉积于水中,在适宜温度下被迅速分解,使池水生态环境恶化,一旦发生水质恶化,鱼类的摄食、生长都将受到严重影响,甚至导致...     

食品蛋白电渗透脱水机理的研究

电渗透脱水应用在食品蛋白质的脱水方面尚未达到实用阶段,这是因为食品蛋白组成复杂,关于其机理研究不多,该研究以大豆分离蛋白、玉米蛋白和豆腐渣等为原料,探讨了不同电压、压力及缓冲液等实验条件下,这些含水物料的电渗透脱水效果和规律。实验表明电渗透脱水不仅速度快、效率高,还有节能效果。研究也对食品物质电渗透脱水的关键技术进行了分析,从原理和技术角度对其在食品脱水干燥领域的应用提出了新思路。     

不同发育阶段日本落叶松人工林枯落物层微生物群落特征

为探寻日本落叶松人工林在中龄林或近熟林阶段地力衰退的机制,以分子生物学实验手段与常规实验分析方法结合,分别对不同发育阶段林分枯落物未分解层、半分解层以及全分解层微生物的数量、群落结构以及理化性质进行分析,并采用冗余分析法探索枯落物层微生物群落结构与理化性质的相关性。结果表明：枯落物储量及养分储量随林分发育呈倒“V”字型变化趋势,在近熟林阶段最大,微生物数量、均匀度指数在中龄林或近熟林最低。不同发育阶段林分优势细菌种类基本相同,但相对含量不同;优势真菌的种类明显不同,尤其是在近熟林半分解层。中龄林与近熟林未、半分解层受环境因素影响较大,主要受pH、有效磷、碱解氮、速效钾、全钾、C/N以及林下植被生物量影响。因此,日本落叶松纯林在中龄林与近熟林阶段需强化植被管理,适时开展修枝间伐等经营措施,促进林下植被发育、改善枯落物性质,加速养分循环,缓解地力衰退。     

豆腐渣混合苹果渣固态发酵改善纤维适口性

为了改善豆腐渣发酵后膳食纤维的适口性,适量混合部分苹果渣,利用其糖分提高酿酒酵母的发酵效率,并对其固态发酵工艺条件进行优化。采用单因素和正交试验方法优化的较佳发酵条件为pH值为8、发酵温度22℃、豆腐渣与苹果渣质量比2∶1、酿酒酵母接种量8%、发酵时间48 h。在优化发酵条件下,豆腐渣和苹果渣混合物中粗纤维的质量分数由发酵前的107.8 mg/g下降到发酵后的64.2 mg/g,降解率为40.45%。混合苹果渣的固态发酵极大地改善了膳食纤维的适口性,可以作为健康食品原料广泛使用。     

外源微生物对堆肥理化性质及酶活影响的研究

利用牛粪和稻草为原料进行堆肥实验,通过测定堆肥过程中的温度、含水率等物理、化学指标以及酶活性的变化,研究了接种外源微生物对堆肥过程的影响。结果表明,接种外源微生物比对照提前2d达到高温期,并且维持时间长。大肠杆菌数量及植物毒性比不接种大幅度降低,纤维素酶、脲酶、多酚氧化酶、过氧化氢酶均有所增加。说明接种外源微生物可以使堆肥中微生物数量增多,加速堆料中有机物的分解,加快堆肥腐熟,缩短堆肥反应的进程,对优化堆肥工艺具有重要的意义。     

A Laboratory Method to Investigate Gaseous Emissions And Solids Decomposition During Composting Of Municipal Solid Wastes

A laboratory method was developed to quantify CO₂, NH₃ and VOC yields and to follow solids decomposition during composting of MSW or its components. All organic substrates were shredded, water and nutrients were added to near optimum levels prior to composting, and composting was continued until feed materials reached approximately the full extent of decomposition. Twenty five L stainless steel digesters were used and aluminum packing was mixed with the wastes to facilitate airflow. Thermophilic temperatures were maintained and air supplied in excess. Nutrients were added to reach an initial C/N ratio of approximately 30. CO₂ and NH₃ gases in the exit air stream were captured in alkaline and acidic solutions, respectively, and quantified through titration on a cumulative basis. VOC traps, prior to the gas traps, captured emitted volatile organic compounds, which were quantified on a cumulative basis. Solids were analyzed for hot water soluble matter, fats and lipids, cellulose, hemicellulose and lignin/humus. Food wastes, yard wastes and mixed paper produced approximately 368, 220 and 153 g C-CO₂/dry kg and approximately 40.5, 4.6 and 2.0 g N NH₃/dry kg of starting material, respectively. VOC volatilization profiles had a decreasing trend with composting. Partially composted MSW produced 8.2 mg/dry kg of 8 selected VOCs. CO₂, NH₃ and VOC recovery tests resulted in efficiencies of 98.6%, 97.6% and 94.6% respectively. Reproducibility of the solids decomposition and gaseous emissions measurements was observed. Carbon and nitrogen mass balance closures ranged from 85.5% to 117.1% and 32.2% to 175% respectively.     

Decomposition of Emergent Aquatic Plant (Cattail) Litter Under Different Conditions and the Influence on Water Quality

Decomposition of aquatic plant might generate a significant influence on the receiving water body. In this study, decomposition of emergent aquatic plant (cattail) litter was investigated under different conditions to determine the influencing level of the decomposition process on the water quality. Different litter addition rates (0.1, 0.5, 1.0 g L^?1), temperature changes, sediment additions, and kinestates (static and dynamic conditions) were selected as the influencing factors for the decomposition process. The results suggested that the decomposition process could be all accelerated when conducted at a higher litter addition rate, under a cold condition, with sediment addition or on dynamic condition, respectively. Additionally, the maximum ratio of releasing carbon to nitrogen (C/N) was increased when the decomposition process was conducted with a higher litter addition rate, under a cold condition (31.0), with sediment addition (24.6) and on a dynamic condition (28.0), respectively, and the C/N ratios were all higher than that with only 0.5 g L^?1 litter addition (24.5), suggesting that lowering of water temperature, sediment addition, and increasing of oxygen might also enhance the C/N. The high C/N released during the decomposition process implied that the cattail litter might be utilized as the potential organic carbon source for nitrogen removal in the CW system.     

Role of organic fractions on C decomposition and N mineralization of animal wastes in soil

The relative contributions of water-soluble, water-non-soluble, Van Soest-soluble, and neutral detergent fiber (NDF) fractions of pig slurry (PS), cattle slurry (CS), cattle farmyard manure (FYM), and composted cattle farmyard manure (CFYM) to the overall C and N mineralization of the raw wastes were studied by incubating treated soil for 107 days at 15°C under non-limiting N conditions. The C or N mineralization of soluble fractions was calculated from the difference between C or N mineralization of the raw and non-soluble fractions. The organic N content of raw wastes ranged from 15 to 32 mg N g⁻¹ dry matter and organic C to organic N ratio from 13 to 29. The water-soluble fraction (SOL_W) was close to 100 mg C g⁻¹ raw waste C for CS, FYM, and CFYM but reached 200 mg C g⁻¹ for PS. The Van Soest-soluble fraction (SOL_VS) was the main fraction for PS, CS, and CFYM (>500 mg C g⁻¹ raw waste C) but only 303 mg C g⁻¹ raw waste C for FYM. Both soluble and non-soluble fractions contributed to C decomposition of slurries, with half to more than half of the decomposed C derived from the degradation of soluble compounds. Most of the C decomposed from FYM was derived from the large NDF fraction, but the contribution from the water-soluble C to the decomposition was also significant. Carbon mineralization of CFYM was due to the degradation of the NDF fraction, whereas soluble C did not contribute. Amounts of N mineralized or immobilized by raw wastes and non-soluble fractions at the end of incubation were significantly correlated (P < 0.01) with their organic C to organic N ratio. The contribution of the Van Soest-soluble fraction to N mineralization varied greatly between the four wastes. Finally, large differences in the C degradability and N availability of the water and Van Soest-soluble fractions were demonstrated.     

当量比对猪粪空气气化效果的影响

畜禽养殖废弃物的减量化和资源化利用是畜禽养殖污染控制的主要途径,热化学处理技术为畜禽养殖废弃物的资源化利用提供了新的方式。试验采用自主设计制造的流化床反应器,对猪粪展开以空气为气化剂的气化研究。该文主要考察了当量比（ER）对气化过程和效果的影响,结果表明ER对气化过程的影响具有双重性和复杂性。ER的改变直接影响反应器内流化气体的流动速度,对反应器内温度场分布产生显著影响,随着ER的提高,使氧化还原区和高温区向反应器上部移动。ER值升高,固体得率减小,对热解气化有利,但ER值过大,使液态产物增加,对气化过程不利。燃气热值随ER值升高而降低,碳转化率随ER值升高而升高,ER值对气化效率的影响呈波动特性。猪粪气化的ER调节范围应该在0.25左右。在实际生产中根据反应器内温度分布情况、气体输出情况和反应器内的物料流化状况等对ER的作适当调控非常重要。     

13C solid-state NMR assessment of decomposition pattern during co-composting of sewage sludge and green wastes

The fate of organic matter during composting is poorly understood. Therefore, we analysed composts of sewage sludges and green wastes (44 samples representative of 11 stages of biodegradation) by conventional chemical methods: pH, humic (HA) and fulvic acid (FA) content, C, N and organic matter (OM) content, and by ¹³C CPMAS NMR to assess the decomposition process of the organic matter. Chemical changes clearly occurred in two phases: first, decomposition of OM during the first 2 months was characterized by decreased C/N ratios, OM content and increased pH; and second, a humification process with increased HA/FA ratios. NMR spectrum changes confirmed this pattern, with an increase in aromaticity and a decrease in alkyl C. A decrease of syringyl to guaiacyl ratio (S/G), a sign of lignin transformation, also indicated humification during composting. NMR spectroscopic properties of composts were also studied by means of principal components analysis (PCA) and revealed changes according to the degree of compost maturation. The factorial map presents a chronological distribution of composts on the two first principal components. The influences of eight chemical factors on the PCA ordination of composts as monitored by their evolution by NMR were also studied by multivariate analyses. PCA clearly indicated two phases: the rapid decomposition of organic matter followed by the formation of humic‐like substances. The first phase, that is ‘new’ composts, was strongly correlated with OM contents, pH and C/N ratios whereas the second phase, corresponding to ‘old’ compost, was correlated with pH, HA content and HA/FA ratio. These results confirm that knowledge of the formation of humic substances is indispensable to suitable monitoring of the composting process.     

Zelluloseabbau während der Heißrotte von Siedlungsabfällen

Degradation of cellulose during high-temperature composting of municipal wastes Model experiments were carried out to investigate the breakdown of cellulose during the decomposition of municipal wastes at high temperatures. At 70°C only small amounts of cellulose were decomposed. But a very considerable breakdown of cellulose was observed at temperatures of 65°C and below, i.e. at temperatures suitable for the growth and activity of thermophilic microorganisms.     

农田不同肥力条件下玉米秸秆腐解效果

为了探讨农田不同肥力对玉米秸秆腐解转化和能态变化的影响,该文采用砂滤管法在陕西关中高、中等、低3种肥力塿土上进行了480 d的玉米秸秆腐解试验,研究了腐解进程中玉米秸秆的分解率以及有机碳组成和能态变化。结果显示,随着腐解进行,腐解产物中的苯–醇溶性、水溶性组分下降,半纤维素和纤维素含量先上升后下降,而木质素增加;腐解物的能态呈现上下起伏、下降和相对稳定3个阶段的变化,总体是一个放能过程。腐解产物的热值与其有机碳、苯–醇溶性组分、水溶性组分、半纤维素和纤维素呈显著正相关,但与其灰分、木质素、腐殖物质含量呈显著负相关。腐解480 d,3种肥力间比较发现,玉米秸秆在中等肥力田块上矿化率最高,低肥力田块上的最低;中等肥力土壤能够促进玉米秸秆中的水溶性有机组分和木质素的分解,而高肥力土壤能够促进苯–醇溶性组分和半纤维素、纤维素分解,并有利于腐殖物质的形成,而且腐解物的能态最高。     

集约化畜禽业粪便资源化对策管见

对集约化畜禽粪便资源化提出四点建议:1.强化农业环境管理,增加对区域环境资源的协调能力,把集约化企业的粪便治理纳入区域生态系统和综合洽理轨道,改变养种脱节状况,充分利用环境自净能力,实现养种互补。2.优化区域资源化技术路线,探寻组合配套技术;优化原则为,优先利用环境容量,粪水和部分粪物就地利用。超负荷部分以商品形式输出,无力输出部分才作废弃物输出。3.以市为单位,建立资源化基金,开拓集资渠道,按治理规划统筹使用,迫使企业纳金尽责,又让其享用行业互助和政府的支持,以保证资金来源。4.组织科技攻关,为猪粪处理和北方冬季粪水利用开辟新路,为深层次利用粪便探索新技术。