水解酸化-磷酸铵镁法-EGSB组合工艺处理大豆蛋白废水

采用水解酸化-磷酸铵镁（MAP）法-EGSB组合工艺对大豆蛋白废水进行处理,考察了水解酸化系统运行效果,并对其运行参数进行优化;提出MAP法对高浓度氨氮废水的处理方法,并评选其处理高浓度氨氮废水的适宜条件。结果表明,水解酸化系统运行稳定,最适pH为7.0,最佳水力停留时间为12 h,氨氮转化率高达95.8%;MAP法处理高浓度氨氮废水的优选条件为n（Mg）：n（N）：n（P）=1：1：0.8,此条件下氨氮去除率为88.3%,磷酸去除率为76.7%;EGSB反应器经过三个月的启动后可稳定运行,有机负荷高达到9.88 kg·（m3·d）-1,COD去除率达到90.0%左右。水解酸化-MAP-EGSB组合工艺在处理大豆蛋白废水时可获得连续稳定的处理效果,为大豆蛋白废水处理的工程化提供了基础依据。     

Management of basiphilous dune slack communities in relation to carbonate accumulation and hydrological conditions

In dune slacks in The Netherlands, a decline of rare mesotrophic basiphilous plant species and their plant communities has been observed in combination with an increase of more productive systems with common, taller acidophilous plant species. This has been attributed to both natural and anthropogenic changes. In a humid climate with a precipitation surplus, as in The Netherlands, the calcium carbonate content of a calcareous soil increases with depth. However, soils in coastal dune slacks, may have a higher carbonate content in the topsoil horizon than in the underlying layers. Carbonates which buffer the pH can prolong the presence of mesotrophic basiphilous plant communities which are of high conservation value. To explain the occurrence of calcareous surface horizons in dune slacks, hydrological and micromorphological analyses were carried out in three dune slacks. Two slacks are situated on the Wadden Sea islands in the northern part of The Netherlands; one on Schiermonnikoog and one on Texel. The third slack is situated in the dunes on the island of Goeree in the southwestern part of The Netherlands. In all three slacks, carbonate occurs as mollusc and gastropod fragments (silt- or sand-sized) and as micritic nodules in the topsoil layer, due to aeolian deposition and sedimentation by water.In situ carbonate accumulation (calcitans and calcareous crusts) due to CO₂ release in inundated and/or capillary rise of calcareous groundwater near, or at the soil surface. Accumulation of carbonate also occurs as a result of biological activity by algae in the topsoil of the Goeree site. In general, hydrological processes maintaining high levels of calcareous groundwater are a prerequisite for the maintenance of high carbonate levels in topsoils. Such levels are necessary for the conservation and management of basiphilous pioneer vegetation.     

光照条件对跑道池光生物反应器内蛋白核小球藻生长特性的影响

本文采用多孔曝气管的曝气方式,以蠕动泵为藻液循环的动力,研究了气体流量、光照强度、光照周期等因素对跑道池光生物反应器内蛋白核小球藻生长与代谢特性的影响,并利用傅里叶红外光谱半定量法对不同光照条件下藻细胞内蛋白质、油脂以及多糖含量变化进行了分析。研究结果表明,适当的气体流量、光照强度和光照周期有利于跑道池内蛋白核小球藻细胞的生长和代谢。在本实验条件下,在最佳气体流量2 000 mL/min条件下,光照强度为3 500 μW/cm2,光照周期为16:8时最有利于蛋白核小球藻的生长;光照强度为2 000 μW/cm2和光照周期为16:8的条件均有利于藻细胞内油脂的积累。     

伴矿景天汁液中重金属形态及絮凝沉淀效果优化

超积累植物伴矿景天在镉污染土壤修复方面展现出广泛的应用前景,而收获后鲜样的快速脱水处置是目前急需解决的问题。采用连续浸提法研究了伴矿景天植株中重金属浓度及形态,正交实验探讨了汁液在絮凝沉淀过程中重金属及化学需氧量(COD)的去除效果及其影响因素,Cd离子选择电极测定了汁液处理前后镉形态变化。结果表明,伴矿景天植株中Cd、Pb主要以活性较低的盐提取态和酸提取态存在,Zn主要以活性较高的乙醇提取态和去离子水提取态存在;汁液中离子态Cd约占总浓度的20%,其余主要为非离子态;絮凝沉淀可有效去除汁液COD和重金属,优选条件pH为10,聚合氯化铝(PAC)投加量2%,搅拌速度为400 r·min-1,该条件下汁液Cd、Pb、Zn和COD去除率分别为81.9%、77.0%、76.4%和55.0%。汁液经絮凝沉淀后,Cd总浓度降低到0.23 mg·L-1,且主要为非离子态。伴矿景天汁液中重金属的形态对汁液的絮凝沉淀效果有较大影响,有机螯合态重金属难以通过絮凝沉淀彻底去除,而离子态重金属在絮凝沉淀中更容易被去除。     

京津冀产业碳排放强度变化及驱动因素研究

为探讨京津冀地区温室气体排放强度变化的影响因素,采用对数平均迪式分解模型及归因分析(LMDI-Attribution)方法,基于1996—2014年数据从细分行业角度进行研究。针对温室气体排放强度作产业结构、能源强度和排放因子三因素LMDI乘法分解,对温室气体排放强度变化的影响效应作归因分析,量化4个行业对分解因素影响效应的贡献,得到以下主要结论:1996—2014年京津冀地区温室气体排放强度主要呈现下降趋势,累计下降23.05%。其中,能源强度是温室气体排放强度下降的主导因素,其影响效应为-61.18%,对这一影响效应贡献最大的是工业,并且四大经济部门均通过能源强度在不同程度上使得温室气体排放强度有所减小,可见"阶梯电价"、"千家企业节能项目"、"十大重点节能项目"等相关政策在工业发展中对提高能源效率的作用明显。产业结构使得温室气体排放强度增加23.53%,其主要贡献者是工业,说明"工业产品出口退税率调整"等一系列政策的效果不明显;然而农业则使得温室气体排放强度降低,贡献值为3.09%。碳排放因子在1996—2014年间对温室气体排放强度的影响为60.47%,是京津冀地区温室气体排放强度增加的主要因素,说明京津冀地区的能源结构不合理。工业对这一效应的贡献最大为55.97%。可见,工业在京津冀地区的温室气体减排工作中起到最为关键的作用。     

钠型丝光沸石去除猪场废水中营养元素的试验研究

以钠型丝光沸石为试验材料进行猪场废水同步脱氮除磷研究,考察了沸石投加量、吸附时间、pH、Ca²⁺和Mg²⁺浓度对钠型丝光沸石同步去除氨氮和磷的影响。结果表明,在沸石投加量为300 g/L,pH为8.0～9.0,吸附时间为4 h的条件下,钠型丝光沸石对氨氮的去除率达到92%,对磷的去除率达到86%。随着pH的升高,氨氮和磷的去除率均先升高再降低,氨氮的去除率在pH为8.0时达到最高,为90%;磷的去除率在pH为9.0时达到最高,为85%。Ca²⁺浓度的增加对沸石去除氨氮的影响不大,但对磷的去除效果影响较显著,在P与Ca的摩尔比为1:6,pH为9.0时,磷的去除率达到88%。Mg²⁺浓度的增加对沸石去除氨氮和磷的效果影响较显著,在P与Mg的摩尔比为1:4,pH为10.0时,废水中氨氮和磷的去除率达到93%和91%。     

VERIFICATION OF THE RHEA-OROGRAPHIC-PRECIPITATION MODEL1

ABSTRACT: Observed April 1 snowpack accumulations within and near the Gunnison River basin in southwestern Colorado are compared with simulations from the Rhea-orographic-precipitation model to determine if the model simulates reliable magnitudes and temporal and spatial variability in winter precipitation for the basin. Twenty simulations of the Rhea model were performed using‘optimal’parameter sets determined for 10-kilometer (km) grids (10-km by 10-km grid cells) through stochastic calibration. Comparisons of Rhea-model simulations of winter precipitation with April 1 snowpack accumulations at 32 snowcourse stations were performed for the years 1972–1990. For most stations and most years the Rhea model reliably simulates the temporal and spatial variability in April 1 snowpack accumulations. However, in general, the Rhea-model underestimates April 1 snowpack accumulations in the Gunnison River basin area, and the underestimation is greatest for locations that receive the largest amount of snow. A significant portion of the error in Rhea-model simulations is due to the calibration of the Rhea model using gauge-catch precipitation measurements which can be as much as 50 percent below actual snowfall accumulations. Additional error in the Rhea-model simulations is a result of the comparison of gridded precipitation values to observed values measured at points.     

SPATIAL VARIATIONS OF WATER LOSS DURING DROUGH A CASE STUDY1

ABSTRACT: A regional water conservation system for drought management involves many uncertain factors. Water received from precipitation may stay on the ground surface, evaporate back into the atmosphere, or infiltrate into the ground. Reliable estimates of the amount of evapotranspiration and infiltration are not available for a large basin, especially during periods of drought. By applying a geographic information system, this study develops procedures to investigate spatial variations of unavailable water for given levels of drought severity. Levels of drought severity are defined by truncated values of monthly precipitation and daily streamflow to reflect levels of water availability. The greater the truncation level, the lower the precipitation or streamflow. Truncation levels of monthly precipitation are recorded in depth of water while those of daily streamflow are converted into monthly equivalent water depths. Truncation levels of precipitation and streamflow treated as regionalized variables are spatially interpolated by the unbiased minimum variance estimation. The interpolated results are vector values of precipitation and streamflow at a grid of points covering the studied basin. They are then converted into raster‐based values and expressed graphically. The image subtraction operation is used to subtract the image of streamflow from that of precipitation at their corresponding level of drought severity. It is done on a cell‐by‐cell basis resulting in new attribute values to form the spatial image representing a spatial distribution of potential water loss at a given level of drought severity.     

酒精废水消化液预处理试验研究

高浓度酒精糟液经厌氧生物处理后排出的消化液COD浓度为4500—6000mg/L,SS浓度高这1500—2．600mg,／L,且由于微小沼气泡附着在厌氧污泥上,沉降性能很差,难以与消化液相分离,对后续处理十分不剁。本研兜采用预曝气．化学混凝沉淀组合工艺,对该消化液进行去除高浓度SS的顸处理试验,研究探讨了曝气时间、混凝剂种类和投加量对SS和COD去除效果的影响。试验结果表明,预曝气．化学混凝沉淀组合工艺对消化液SS的去除效果十分显著。当预曝气时间为6．0h,FeCl3投加量为100mg/L时,消化液的SS去除率75．4％,COD去除率24．3％,可为后续的好氧生物处理提供较为有利的水质和负荷条件。     

PRECIPITATION CHANGES FROM 1956 TO 1996 ON THE WALNUT GULCH EXPERIMENTAL WATERSHED1

ABSTRACT: The climate of Southern Arizona is dominated by summer precipitation, which accounts for over 60 percent of the annual total. Summer and non‐summer precipitation data from the USDA‐ARS Walnut Gulch Experimental Watershed are analyzed to identify trends in precipitation characteristics from 1956 to 1996. During this period, annual precipitation increased. The annual precipitation increase can be attributed to an increase in precipitation during non‐summer months, and is paralleled by an increase in the proportion of annual precipitation contributed during non‐summer months. This finding is consistent with previously reported increases in non‐summer precipitation in the southwestern United States. Detailed event data were analyzed to provide insight into the characteristics of precipitation events during this time period. Precipitation event data were characterized based on the number of events, event precipitation amount, 30‐minute event intensity, and event duration. The trend in non‐summer precipitation appears to be a result of increased event frequency since the number of events increased during nonsummer months, although the average amount per event, average event intensity, and average event duration did not. During the summer “monsoon” season, the frequency of recorded precipitation events increased but the average precipitation amount per event decreased. Knowledge of precipitation trends and the characteristics of events that make up a precipitation time series is a critical first step in understanding and managing water resources in semiarid ecosystems.