河北省张北县土地质量地球化学调查评价—以台路沟乡为例

为助力河北省张家口市张北县脱贫攻坚,基于台路沟乡土地质量调查数据,分析了该乡土壤元素地球化学特征,划分了土壤地球化学等级、灌溉水等级,以及土地质量地球化学等级。养分元素主要较缺乏磷及速效钾、硼、铜、硒。土壤环境地球化学综合评价等级以一等无风险区为主,占总面积的98.88%。二等风险可控区占总面积的1.12%,主要是受Ni元素的污染影响。约97.49%的面积符合绿色食品产地环境质量标准,具有开发绿色食品的巨大潜力。灌溉水各元素均处于限量标准以下,为优质灌溉水。土地质量地球化学等级以良好级质量为主,占总面积的66.46%;优质级区占总面积的18.57%,中等级占总面积的14.97%,无差等、劣等级。相关成果可为张北县土地利用规划、水源涵养功能区和生态环境支撑区建设、资源环境承载力评价和国土空间适宜性评价提供基础资料。     

Nitrous oxide generation in full-scale biological nutrient removal wastewater treatment plants

International guidance for estimating emissions of the greenhouse gas, nitrous oxide (N₂O), from biological nutrient removal (BNR) wastewater systems is presently inadequate. This study has adopted a rigorous mass balance approach to provide comprehensive N₂O emission and formation results from seven full-scale BNR wastewater treatment plants (WWTP). N₂O formation was shown to be always positive, yet highly variable across the seven plants. The calculated range of N₂O generation was 0.006-0.253 kgN₂O-N per kgN denitrified (average: 0.035 ± 0.027). This paper investigated the possible mechanisms of N₂O formation, rather than the locality of emissions. Higher N₂O generation was shown to generally correspond with higher nitrite concentrations, but with many competing and parallel nitrogen transformation reactions occurring, it was very difficult to clearly identify the predominant mechanism of N₂O production. The WWTPs designed and operated for low effluent TN (i.e. <10 mgN L⁻¹) had lower and less variable N₂O generation factors than plants that only achieved partial denitrification.     

Development of a mechanistic model for biological nutrient removal activated sludge systems and application to a full‐scale WWTP

In wastewater treatment plants (WWTPs) the production of nitrite as an intermediate in the biological nutrient removal (BNR) process has been widely observed, but not been taken into account by most of the conventional activated sludge models yet. This work aims to develop a mechanistic mathematical model to evaluate the BNR process after resolving such a problem. A mathematical model is developed based on the Activated Sludge Model No.3 (ASM3) and the EAWAG Bio‐P model with an incorporation of the two‐step nitrification–denitrification, the anoxic P uptake, and the associated two‐step denitrification by phosphorus accumulating organisms. The database used for simulations originates from a full‐scale BNR municipal wastewater treatment plant. The influent wastewater composition is characterized using batch tests. Model predictions are compared with the measured concentrations of chemical oxygen demand (COD), NH‐N, NO‐N, NO‐N, PO‐P, and mixed liquid volatile suspended solids. Simulation results indicate that the calibrated model is capable of predicting the microbial growth, COD removal, nitrification and denitrification, as well as aerobic and anoxic P removal. Thus, this model can be used to evaluate and simulate full‐scale BNR activated sludge WWTPs. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

基于GIS和SWAT模型的清江流域面源污染模拟研究

 水体面源污染评价研究是一项复杂的工作,涉及面广和要求有较长时间序列的数据。面源污染模型很大程度上依赖于对于流域的特征描述的相关参数,因此提高输入模型参数的精度,有利于提升流域面源污染的径流、泥沙和营养物质的产出模拟效果。GIS和面源污染模型的有机结合是当前面源污染模拟研究最有效的方法。本研究建立了基于GIS的基础数据库,其中包括DEM、土壤类型、土地利用、气象数据以及农业耕作管理数据等。面源污染模拟的产生和形成具有很大的不确定性,这更加增加了监测和控制面源污染的难度。探索影响面源污染的主要因素,研究其不确定性对于提出和制定污染控制措施至关重要。本研究进行了清江流域面源污染的参数敏感性分析,根据观测数据对SWAT模型进行验证和率定,并利用SWAT模型进行模拟,揭示了清江流域面源污染的时空分布特征,确定了清江流域水土流失风险区。结果表明清江流域的面源污染主要发生在丰水期,不同的土地利用方式、农业耕作制度以及降水等是影响径流量和营养物质产生的主要因素。     

Mechanical sludge disintegration for the production of carbon source for biological nutrient removal

The primary driver for a successful biological nutrient removal is the availability of suitable carbon source, mainly in the form of volatile fatty acids (VFA). Several methods have been examined to increase the amount of VFAs in wastewater. This study investigates the mechanism of mechanical disintegration of thickened surplus activated sludge by a deflaker technology for the production of organic matter. This equipment was able to increase the soluble carbon in terms of VFA and soluble chemical oxygen demand (SCOD) with the maximum concentration to be around 850 and 6530 mgl(-1), for VFA and SCOD, respectively. The particle size was reduced from 65.5 to 9.3 microm after 15 min of disintegration with the simultaneous release of proteins (1550 mgl(-1)) and carbohydrates (307 mgl(-1)) indicating floc disruption and breakage. High performance size exclusion chromatography investigated the disintegrated sludge and confirmed that the deflaker was able to destroy the flocs releasing polymeric substances that are typically found outside of cells. When long disintegration times were applied (>or=10 min or >or=9000 kJkg(-1)TS of specific energy) smaller molecular size materials were released to the liquid phase, which are considered to be found inside the cells indicating cell lysis.     

Reported Use of Reduced-sugar Foods and Beverages Reflect High-quality Diets

ABSTRACT: The purpose of this study was to determine differences in nutrient and energy intakes and in quantity of food eaten, and to compare the knowledge, attitudes, and practices of users of reduced-sugars foods and beverages with those who use only the full sugar versions of the same products. Records for adults (≥ 20 y old) responding to the 1994–1996 Continuing Survey of Food Intakes by Individuals (CSFII) and the Diet Health and Knowledge Survey were used. CSFII food lists were scanned for both full and reduced-sugar versions of yogurt, cocoa, and other milk beverages, frozen and gelatin desserts, puddings, breads, cookies, cakes, fruit drinks, carbonated and noncarbonated drinks, confectionary products, and sweeteners. Recalls were sorted for those reporting use of only full sugar (FS) products and those reporting mixed use of full sugar and reduced-sugar (RS) versions. Comparisons were made between demographic characteristics, body mass index, food group servings, food intake amounts, and nutrient densities. When compared with FS users, RS users consistently reported significantly higher intakes of fruit, lower intakes of discretionary fat and added sugars, and equal or lower intakes of other foods (in gram amounts), except for greater intake of yogurt and frozen and gelatin desserts. RS users tended to report similar or higher micronutrient intakes compared with FS users. After adjusting for energy intake, significantly higher micronutrient intakes were found for both males and females consuming RS foods and beverages (13 and 15 of 17 nutrients, respectively).     

Influence of lipase and/or emulsifier addition on the ileal and faecal nutrient digestibility in growing pigs fed diets containing 4% animal fat

Information on the addition of lipase and/or emulsifiers to less digestible or saturated fat sources, such as tallow or other animal fats, used in swine feeding is very limited. Therefore, in a 4 × 4 Latin square design, the effects of adding lipase (0.05% L5, microbial source) and/or an emulsifier (0.3% Lysoforte) on the apparent ileal (AID) and faecal (AFD) digestibility of the main nutrients and fatty acids in particular were studied with four ileal‐cannulated growing pigs (female, initial live weight 20 kg) fed diets containing barley/soybean meal supplemented with 4% animal fat. The fat source contained 35% saturated (S) and 65% unsaturated (U) fatty acids. All diets were free of antibacterial substances (antibiotics, copper sulphate or zinc oxide beyond requirements), in order to avoid interactions between the parameters studied and the gut flora. Lipase addition did not affect the AID or AFD of fat. However, the digestibility of minor fatty acids (C6:0, C14:0) was significantly improved by lipase at both ileal and faecal level. On the other hand, lipase supplementation (P < 0.05) improved the AID of dry matter (DM) and energy as well as the AFD of DM, organic matter (OM), crude protein (CP), ash and energy. Addition of an emulsifier did not have any significant influence on the AID or AFD of fat, while the AID values of DM, OM, CP and energy as well as the AFD values of DM, OM, CP and ash were significantly (P < 0.05) improved. Adding lipase in combination with an emulsifier to the diets decreased (P < 0.05) the AID and AFD of fat, with minor effects on the AID and AFD of the non‐fat components of the diet. The lack of improvement in the digestion of fat by exogenous lipase and/or emulsifier may be related to the rather high U/S ratio (0.65:0.35) of the animal fat source used and to the mode of incorporation of the emulsifier (no pre‐dispersion in the fat source). Furthermore, during the trial the diets, stored at room temperature, showed a steady increase in their content of free fatty acids (to more than 700 g kg^?1 fat), due to endogenous lipase activity, leaving less room for upgrading the digestion of animal fat by exogenous lipase and/or emulsifier. Copyright © 2004 Society of Chemical Industry     

TYM-A酶酶法生产蚕丝营养素和丝多肽的研究

该文研究了适于蚕丝营养素和丝多肽酶解的诱变株米曲霉CV-8-1和芽孢-1-1的选育，2诱变株的最佳酶解条件的优化，试验确定TYM-A复合蛋白酶的最佳配比及最佳酶解小试工艺条件。     

鲁中(费县)烟区土壤养分特征及其调节措施

山东费县适宜种植优质烟的土壤主要有3个亚类,分别属于普通棕壤、淋溶褐土和潮褐土.在费县不同类型的地块采集178个土壤样品进行分析化验,结果表明,费县主要植烟土壤的pH值介于微酸性至中性范围,有机质和有效磷含量中等偏低,大部分土壤有效氮、速效钾含量中等偏高.为此提出该区烟草施肥中应该掌握"控氮、增磷、稳钾"的施肥对策.     

营养盐对球等鞭金藻生长及多糖等生化成分含量的影响

通过研究营养盐浓度对球等鞭金藻生长及其细胞生化成分含量的影响，探讨了球等鞭金藻细胞生长与其细胞内多糖、叶绿素、蛋白质营养成分的关系。结果表明，所选用的4种营养盐在一定的浓度范围内均对球等鞭金藻的生长和细胞生化成分有很大的影响，这4种营养盐的适宜浓度依次为NaNO_3-N10mg／L、FeCl_3-Fe0.10mg／L、KH_2PO_4-P0.6mg／L、Na_2SiO_3-Si0.3mg／L。