摇动床生物膜反应器和活性污泥法组合技术处理高浓度有机废水的研究

利用摇动床生物膜反应器(简称摇动床)技术具有的容积负荷高与污泥产量低的优点,在普通活性污泥池的前部填充高性能丙烯酸树脂纤维(Biofringe)填料,研究了摇动床和活性污泥法组合技术处理高浓度有机废水的有效性。结果表明,该组合技术具有很强的有机物去除能力,当进水COD平均质量浓度由1500mg/L上升到2514mg/L时,出水COD的平均去除率基本保持在96%以上;整个运行阶段的出水COD浓度均满足《污水综合排放标准》(GB8978—1996)的二级标准;当进水NH4+-N浓度增加时,NH4+-N的去除率由99.7%降低到76.5%,但是在试验运行的整个阶段,摇动床和活性污泥法组合技术系统都表现出较强的硝化能力;活性污泥池中最高的混合液悬浮固体(MLSS)质量浓度为10625mg/L,最高MLSS约为普通活性污泥法的4倍;运行结束后的污泥产率为0.186,污泥产率仅为普通活性污泥法的50%左右。     

Treated wastewater irrigation effect on soil, crop and environment： Wastewater recycling in the loess area of China

A study was carried out at the Loess Plateau in Dongzhi,China,to test the feasibility of using secondary treatment sewage effluent and to determine whether the water quality would then meet the recommended irrigation norm.Seven crops,including celery,wheat, maize,millet,apples,rapeseed and yellow beans,were tested in the study.Physical and chemical properties of the soil,crop yield and quality and leachate at different soil depths were measured.In most cases,the quality of the crops that made use of treated sewage was not distinctively different from those that did not use treated sewage.However,yields for the former were much higher than they were for the latter.Leachates at different soil depths were analyzed and the results did not show alarming levels of constituents.For a period of approximately 14 months,the treated sewage irrigation had no significant effect on the loess soil and no cases of illness resulting from contact with the treated sewage were reported.With treated sewage irrigation,a slight increase in the organic content of the soil was observed.     

HYDROLOGIC RESPONSES OF AN AGRICULTURAL WATERSHED TO VARIOUS HYDROLOGIC AND MANAGEMENT CONDITIONS1

ABSTRACT: The hydrologic responses from an agricultural watershed in southeast Nebraska were investigated under an array of physiographic, hydrologic, meteorologic, and management conditions. For analytical purposes, the hydrologic responses were narrowed to include only runoff and sediment yield. The study was performed by utilizing the ANSWERS (Areal Nonpoint Source Watershed Environment Response Simulation) hydrologic-simulation model. Results of this study indicate that, generally, nonstructural (agronomic) Best Management Practices (BMPs) have a more significant impact in controlling erosion and nonpoint-source pollution than structurally oriented BMPs. The percentage of reduction in average soil loss as a result of changing tilage systems from conventional to chisel plow was in the mid-40s. The corresponding percentages of reduction in sediment yield from the watershed under minimum tillage and no-till systems were in the mid-60s and mid-80s, respectively. The impact of these management strategies on runoff varied considerably. That is primarily based on the watershed's antecedent soil moisture condition, land use, and the growth stage of crops. Generally, an intense, short, thunderstorm type of rainfall event had more relative impact on runoff, and therefore sediment yield than a long, gentle, and steady event.     

A novel approach to treat combined domestic wastewater and excess sludge in MBR

Domestic wastewater was treated by combined anaerobic biofilm-aerobic membrane bioreactor(MBR) process, and part biomass in MBR was withdrawn, to treat with ozone, then the ozonated sludge was returned to anaerobic inlet. In aerobic MBR, MLSS and DO were controlled at 3000—3500 mg/L and 0.8 mg/L respectively. Comparing the experimental results of two stages, it was noticed that ozonation did not affect the removal efficiency for organics but had a significant influence on the removals of NHs-N and TN. During the ozonation period of two months, no excess sludge was wasted, and a zero sludge yield was obtained.     

厌氧—好氧处理高得率浆APMP废水的研究

设计了生物处理高得率浆碱性过氧化氢机械浆 (APMP)废水厌氧 (UASB)—好氧 (SBR)组合技术 ,结果表明该技术可使 APMP废水 COD去除率达 90 .3 %。并用计算机处理实验结果 ,建立了厌氧—好氧关联方程及 SBR降解 APMP废水的动力学关系式。     

Optimizing carbon sequestration in commercial forests by integrating carbon management objectives in wood supply modeling

This paper provides a methodology for generating forest management plans, which explicitly maximize carbon (C) sequestration at the forest-landscape level. This paper takes advantage of concepts first presented in a paper by Meng et al. (2003; Mitigation Adaptation Strategies Global Change 8:371–403) by integrating C-sequestration objective functions in existing wood supply models. Carbon-stock calculations performed in Woodstock^TM (RemSoft Inc.) are based on C yields generated from volume table data obtained from local Forest Development Survey plots and a series of wood volume-to-C content conversion factors specified in von Mirbach (2000). The approach is used to investigate the impact of three demonstration forest-management scenarios on the C budget in a 110,000 ha forest in south-central New Brunswick, Canada. Explicit demonstration scenarios addressed include (1) maximizing timber extraction either by clearcut or selection harvesting for greatest revenue generation, (2) maximizing total C storage in the forest landscape and in wood products generated from harvesting, and (3) maximizing C storage together with revenue generation. The level of clearcut harvesting was greatest for scenario 1 (≥15 × 10⁴ m³ of wood and ≥943 ha of land per harvesting period), and least for scenario 2 (=0 m³ per harvesting period) where selection harvesting dominated. Because softwood saw logs were worth more than pulpwood ($60 m⁻³ vs. $40 m⁻³) and were strategic to the long-term storage of C, the production of softwood saw logs exceeded the production of pulpwood in all scenarios. Selection harvesting was generally the preferred harvesting method across scenarios. Only in scenario 1 did levels of clearcut harvesting occasionally exceed those of selection harvesting, mainly in the removal of old, dilapidated stands early in the simulation (i.e., during periods 1 through 3). Scenario 2 provided the greatest total C-storage increase over 80 years (i.e., 14 × 10⁶ Mg C, or roughly 264 Mg ha⁻¹) at a cost of $111 per Mg C due to lost revenues. Scenarios 3 and 1 produced reduced storage rates of roughly 9 × 10⁶ Mg C and 3 × 10⁶ Mg C, respectively; about 64% and 22% of the total, 80-year C storage calculated in scenario 2. The bulk of the C in scenario 2 was stored in the forest, amounting to about 76% of the total C sequestered.     

规模化牲畜养殖场的环境效应及其对策

通过对江苏省2个典型地区的4个生猪养殖场的饲料、牲畜排泄物、土壤、地表水及水土水中养分状况的调查采样与分析，对牲畜规模养殖的环境效应进行了评价。在此基础上，对牲畜养殖排泄物的养分管理与资源化利用提出了建议，并通过对牲畜排泄物中养分状况及作物养分需求状况的分析统计，提出了种植－养殖区域养分平衡管理模式。     

高强钢海洋环境应力腐蚀破裂敏感性的控制因素

首先在不同含碳量的CrMo系列钢上,就模拟海水中应力腐蚀抗力和破裂方式、屈服强度、晶界特性和晶内显微组织随含碳量和回火温度的变化关系进行综合测试分析,得出了碳化物分布尤其是原奥氏体晶界的碳化物微层对高强钢应力腐蚀破裂行为有控制作用的新观点。该观点在实用于装备的高强钢30Cr3SiNiMoV、37SiMnCrMoV和30CrMnSiA以及弹簧钢65Mn在各种环境的应力腐蚀和氢脆行为上得到了验证。     

气候对河南省小麦产量的影响及其变化研究

河南省位于亚热带与温带的气候过渡带 ,小麦产量对气候变化非常敏感 ,气候对小麦产量影响的南北过渡性很明显。文中用正交多项式的方法分离小麦产量 ;用积分回归的方法分析气候对小麦产量的影响。在此基础上 ,首先根据降水量、温度和日照时数对小麦产量影响的区域分布 ,分别把河南省分为4个降水量影响区、4个温度影响区、5个日照影响区 ;然后 ,采用滑动积分回归的方法 ,分别分析了亚热带和温带3个影响因子对小麦产量影响的变化 ;最后 ,讨论了未来气候变化的可能影响。