氧化塘深度对猪场厌氧消化液后处理的影响

采用小试装置对3个不同深度氧化塘处理猪场厌氧消化液的效果进行了研究,结果表明:当平均气温为21.9℃,停留时间在80 ～110天,进水负荷为0.05 m3·m-2d-1的条件下,氧化塘对NH4-N的去除率达到了90％以上,CODcr,TP的去除率分别为50％,40％.硝化作用和藻类的吸收是氧化塘去除NH4-N的主要方式,沉淀作用则是CODcr和TP的主要去除方式,在较长停留时间下,微生物对于溶解性CODcr的分解和同化也能提供一定的去除效果.当平均气温为21.9℃,在表面负荷为0.05 m3·m-2d-1的条件下,有效深度为0.3m和0.7m的氧化塘面积去除负荷分别为1.41 g·m-2d-1,1.49 g·m-2d-1,容积去除负荷分别为4.7g·m -3d-1,2.8g·m-3d-1.虽然较深氧化塘具有较高的面积去除负荷,但较浅的氧化塘却有更高的容积去除负荷.     

两种不同布水方式对生物砂滤池去除厌氧消化液氨氮的影响

在实验室条件下,采用试验生物砂滤柱模拟生物砂滤池系统,研究了雾化和滴渗布水方式对生物砂滤池去除猪场厌氧消化液氨氮的影响,结果表明:在进水水力负荷为0.057 m3.m-2d-1,氨氮平均浓度分别为293 mg.L-1,513 mg.L-1,553 mg.L-1时,雾化布水生物砂滤池对氨氮的平均去除率分别为98.8%,87.4%,75.1%,出水氨氮平均浓度分别为3.61 mg.L-1,64.7 mg.L-1,138 mg.L-1,平均去除负荷分别为16.4 g.m-2d-1,25.4g.m-2d-1,23.5 g.m-2d-1;滴渗布水生物砂滤池对氨氮的平均去除率分别为77.4%,71.4%,59.3%,出水氨氮平均浓度分别为66.3 mg.L-1,147 mg.L-1,225 mg.L-1,平均去除负荷分别为12.9 g.m-2d-1,20.7 g.m-2d-1,18.6 g.m-2d-1;雾化布水可以提高生物砂滤池氨氮的去除率、去除负荷,降低出水氨氮浓度;滴渗布水在进水氨氮平均浓度293 mg.L-1,雾化布水进水氨氮平均浓度293 mg.L-1,513 mg.L-1的条件下,出水氨氮平均浓度可达到《畜禽...     

江坪河放空洞有压洞口段衬砌混凝土冬季温控方案分析

冬季衬砌混凝土施工面临的寒潮等问题,容易导致混凝土产生裂缝.基于有限元分析软件ANSYS,对江坪河放空洞有压段洞口段衬砌厚度为1.0 m的混凝土的拆模时间、围岩特性以及在遭遇寒潮时保温与否等6种不同的方案的进行了分析,并提出相应的温控方案和温控标准供设计与施工参考.     

稻麦平床燃油干燥机的研制

针对农村农户,设计了稻麦平床燃油干燥机,适于小批量稻麦干燥生产。整机设计烘干段采用分体结构,卸粮操作采用旋转方式,并对燃烧器改造及烘干机的有关计算做了阐述。     

基于径向基神经网络的叶轮轴面投影图优化

为了提高余热排出泵的效率,采用拉丁超立方试验设计方法对叶轮轴面投影图上的前盖板圆弧半径、后盖板圆弧半径、前盖板倾角和后盖板倾角4个几何变量进行35组叶轮方案设计,应用ANSYS CFX 14.5软件对余热排出泵进行定常数值模拟,得到设计工况下的效率,应用径向基神经网络建立效率与轴面投影图的4个几何变量之间的近似模型,最后采用遗传算法对近似模型进行极值寻优,获得最优的轴面投影图几何参数组合。研究结果表明:对比原始泵的数值模拟性能曲线和试验外特性能曲线,两者吻合较好;径向基神经网络能较好地预测泵设计点效率;优化的轴面投影图使得余热排出泵的水力效率提高了6.18个百分点,改善了叶轮内流场特性。因此,叶轮轴面投影图的优化设计方法是可行的。     

厌氧生物水处理技术研究进展

在原有脱碳技术基础上,废水厌氧处理在其他领域的研究与应用被不断拓展.本文介绍了近年来厌氧生物处理技术的新发展,从理论和工艺两个方面,综述了厌氧生物脱硫、生物制氢、厌氧氨氧化、厌氧反硝化的原理、研究、技术开发与应用.     

The effect of plastic mulch on the fate of urea-N in rain-fed maize production in a semiarid environment as assessed by 15N-labeling

A better understanding of the fate of fertilizer nitrogen (N) is critical to design appropriate N management strategies in plastic-mulched croplands. We evaluated the effects of plastic mulch on urea-N recovery by crops and loss from soil in furrow-ridge plots, with and without maize (Zea mays L.) cropping, in a semi-arid rain-fed site in China. We applied the same rate of urea-N (281 kg ha⁻¹) to all treatments during the preparation of the furrow-ridges in 2011 and 2012 but ¹⁵N-labeled the urea in 2011 only. We used transparent film to cover all soil surfaces in the mulched treatments and seeded maize in furrows in treatments with crop. In 2011, plastic mulch increased the total N uptake in the aboveground biomass of maize by 53%, whereas it decreased the in-season labeled-N uptake by 19%, compared to non-mulched treatment. At harvest in 2011, in mulched treatments the total labeled-N remaining in the 0−170 cm soil layer was 25% greater whereas unaccounted labeled-N was 69% less, than in non-mulched treatments, regardless of whether maize was cropped. In 2012 the effect of mulch on total maize N uptake was comparable to that in 2011, but the residual soil labeled-N uptake by maize was 63% higher in mulched compared to non-mulched treatment. At harvest in 2012, plastic mulch increased total labeled-N remaining in the 0−170 cm depth in cropped soils and unaccounted labeled-N in non-cropped soils, compared with no mulch. Our results indicate that plastic mulch profoundly changes the fate of urea-N in maize production in cold and dry croplands.     

Study on Optimum Design of Rectangular Sedimentation Tanks

In this paper,the flow velocity fields,suspended solids concentration fields and flow-through curves in rectangular sedimentation tanks with different reaction baffles location,inlet horizontal velocity and length height ratio are simulated in detail using a developed mathematical model given in Reference 2.According to the numerical results,the influence of different reaction baffles location,inlet horizontal velocity and length height ratio on the operating efficiency is analyzed.Finally,the rational reaction baffles location,inlet horizontal velocity and length height ratio are presented.     

Test Analysis of Ecosystem on Functional Groups of Microorganism in Spiral Up- flow Reactor System

The test of functional groups of microorganisms in Spiral Up-flow Reactor System and the correlation between microorganisms in the water and the main environmental factors are studied.The results show that the diversity of microorganisms population in the SUFR system is complex and the bio-community formed in the SUFR system is stable.The close relations between abundance of bacteria and nutrients are found.The correlation between heterotrophic bacteria and COD is 0.949.The correlation between organic phosphate bacteria and TP is 0.815. The correlation between nitrosobacteria and NH_3-N is 0.909. The correlation between disnitrifier bacteria and TN is 0.653.