右旋反式氯丙炔菊酯农药的光化学降解研究

文章研究了时间、初始浓度、溶液pH值、催化剂、β-环糊精等因子对右旋反式氯丙炔菊酯光降解的影响,结果表明:光照时间越长,右旋反式氯丙炔菊酯光解率越高,溶液pH值越高,降解速率越快,初始浓度越低,光解率越高;TiO2催化能提高降解速率,β-环糊精和TiO2共同作用能显著提高右旋反式氯丙炔菊酯的降解速率。     

活性污泥法降解苯酚模拟废水的动力学研究

研究了活性污泥法降解苯酚模拟废水的动力学规律。实验结果表明，活性污泥法对苯酚废水具有良好的降解性能，正常状态下，3h内COD去除率迭90％以上。降解过程符合一级反应动力学方程。不同污泥浓度时反应速率常数K1相差不大，提高苯酚初始浓度K1亦增大。pH值在4．8-9．1范围内，活性污泥保持良好的降解性能，pH值过大或过小时，微生物均受到抑制。在15-35℃，K-随温度的升高而增大，求得温度系数θ为1．054。     

千屈菜种子萌发特性研究

研究千屈菜种子的萌发特性,分析影响种子活力与活力变化规律,正确及时测定种子活力,对指导种子安全贮藏和农业生产具有重要意义。探讨温度、光照和pH值、植物生长调节剂对种子萌发的影响。千屈菜种子具有明显的光促进萌发特性,并表现出温度对光照的补偿作用。不同温度对千屈菜种子的萌芽有显著影响,中性及弱碱性是千屈菜种子萌发的理想条件。     

一株对氯酚降解菌的筛选及降解特性

从制革废水中分离出1株能够降解对氯酚的棒状菌属细菌ZQ-1。该菌株降解对氯酚的最适pH值为6.0~8.0,最适温度为35~40℃。其降解对氯酚的速率与化合物的初始浓度呈负相关。为强化对氯酚的生物降解,本研究从制革废水中分离到1株能够高效降解对氯酚的细菌,并对其降解对氯酚的特性和机制进行分析。目前,尚未发现棒状菌属内有降解对氯酚的成员,该降解菌的发现对氯酚生物净化的工程实践具有重要意义。     

选择精品太阳能的六大标准

耐寒标准：冬天也好用。冬季太阳光照弱，光照时间短，温度低、温差大，热水需求量更大，是考验太阳能的关键时期。     

pH对生物炭改性土甲烷氧化速率的影响

为提高垃圾填埋场生物覆盖层的微生物甲烷氧化能力,本文通过培养瓶试验与土柱试验研究了pH对水稻秸秆生物炭改性土的微生物甲烷氧化速率的影响。结果表明,生物炭是碱性材料,降低生物炭改性土的pH能显著提升其甲烷氧化性能,当生物炭改性土(炭掺量20%)的pH从10.4降低到5.8时,其甲烷峰值氧化速率是初始值的5倍。土柱尺度下,pH=5.8时的稳定甲烷氧化速率是pH=10.4时的5.5倍。这是由于弱酸性下生物炭改性土中甲烷氧化菌与甲烷单加氧酶的活性最高。受土柱堆积情况与空气流通影响,土柱上部的甲烷氧化速率高于下部,大尺度下的甲烷氧化速率明显小于小尺度。     

利用粉煤灰和赤泥制备新型无机复合混凝剂的研究

以粉煤灰和赤泥为原料制备一种新型无机复合混凝剂，研究了产品投放量、废水初始pH值以及温度对混凝效果以及残余铝的影响，得出了产品除浊、除磷、除COD以及低残余铝的最佳投放量、最佳废水初始pH值和温度范围。     

鸡粪高效降解菌群对堆肥的影响

为明确自行筛选开发的高效降解菌对鸡粪发酵的影响,分析研究了其堆肥的主要腐熟指标。结果表明,加入高效降解菌剂的堆肥处理方法温度相对较高,脱水快,pH值适宜,C/N调整较好,种子发芽指数高,堆肥后营养养分含量高,且大肠菌群数量少,堆肥效果较好。     

PACT工艺处理废纸造纸废水的试验研究

通过实验室小试研究了PACT生物强化工艺在废纸造纸废水处理中各类影响因素,考察了粉末活性炭投加与否、粉末活性炭投加量、pH值及HRT对PACT生物强化反应的影响,筛选出最佳工艺。采用GC-MS对污水中的有机物进行了测定,表明PACT工艺具有对难降解物质有较强的降解能力。     

基于饮用水生物稳定性的主体水TOC变化研究

在供水管网中,TOC是支持微生物生长的重要因素,也是严重影响饮用水生物稳定性的因素之一。研究了在加氯之前与加氯之后主体水中TOC的变化规律,并对出现这种变化的原因做出了分析。研究表明,在这两种情况下,TOC都呈现出衰减的趋势,但加氯后的主体水中TOC的衰减速率明显受到了很大影响。     

利用SBR法处理酿酒废水

研究了采用序批式活性污泥法（SBR）处理酒厂生产废水工艺中活性污泥的培养与驯化及工艺参数的选择．分析了不同容积负荷对废水处理效果的影响。实验结果表明：SBR法在室温下就能高效处理高浓度的白酒生产废水,在室温、pH值为中性及好氧-厌氧交替运行的条件下,当废水浓度为1664mg／L、单位COD。有机负荷为0．11kg／（m^3．d）时,对CODCr BOD5、SS的去除率分别达53．8％、95．8％、91％,对N和P的去除效率分别达78％和96％。根据实验分析得知SBR法处理废水影响活性污泥降解性能的主要因素为营养物质的比例、有害物质的积累、溶解氧和pH值。     

超声波协同曝气技术对甲基橙废水的降解研究

研究了超声波协同曝气降解甲基橙溶液效果。结果表明,超声波协同曝气可明显提高甲基橙降解效果,从而节省使用超声波的能量。当曝气流量为0．4L/min、曝气管径在0．2～0．8mm范围,对超声波处理甲基橙效果有差别,但差别不明显。甲基橙溶液的pH值对超声波协同曝气降解甲基橙影响较大,酸性条件下更有利于超声波协同曝气降解甲基橙溶液。     

TiO_2光催化氧化去除水中有机污染物

TiO2光催化氧化去除水中有机污染物,是一种无毒、催化活性高、稳定性好以及抗氧化能力强的新型水处理方法,因此在水处理中日益显示出广阔的前景。介绍了TiO2光催化去除水中有机污染物的研究进展,催化剂及载体,以及反应的影响因素等概况。     

Sustainable natural resource use in rural China: Recent trends and policies

In this paper we provide an overview of recent trends in the availability and quality of land and water resources in rural China, and examine the common presumption that rural resources are rapidly degrading in China. Data based on consistent definitions and measurement methods that have recently become available are used to that end. In addition, we analyse the impact of new policy initiatives to introduce market-based instruments and new institutions to address land degradation and water scarcity problems.We find that the decline in cultivated area has accelerated in the beginning of the new century. Ecological recovery programs, not urbanization and industrialization, are the major factors causing this decline. Ecological recovery programs are also a major force behind the increase in forest land area and the reduction of water erosion. Modest successes can be observed in the protection of wetlands and (until the mid-1980s) for the average quality of cultivated land. On the other hand, degradation of natural grassland and wind erosion have become much more severe in recent decades.In northern China, particularly in the 3-H (Hai and Luan, Huai and Huang) river basins, the availability of water has tightened. Groundwater tables have fallen considerably in the Hai river basin, because farmers increasingly rely on groundwater for irrigation. Evidence on other parts of northern China is mixed. Pollution of surface water is getting worse since the beginning of the 1990s in two major lakes in southern China and until recently in the rivers in northern China. Water quality problems in the larger rivers in southern China are less severe and getting less. These problems are to a large extent caused by agriculture-based non-point source pollution, especially in the major lakes and reservoirs.The sloping land conversion program, water pricing, and the establishment of water user associations and payments for environmental service projects are used as cases to examine the introduction of market-based instruments and new institutions. We argue that less government interference in the implementation of these instruments and institutions is likely to enhance ecological as well the economic benefits. Moreover, supportive measures to improve the functioning of land and labor markets are usually needed to ensure the sustainability of the impact of interventions.     

基于PLC的槽式抛物面太阳能集热器单轴跟踪系统设计

主要对基于PLC的单轴槽式抛物面太阳能集热器跟踪系统设计方案进行了研究,根据宁夏特殊的气候环境采用南北水平单轴跟踪系统设计,大大降低成本耗材,用S7-300软件编程复杂的数学公式作为控制中心。选用角度位移,光强和太阳传感器,用以应变阴天晴天两种状况的使用,极大的提高了集热器的使用效率更好的做的实时掌握跟踪情况。     

Land use change and environmental stress of wheat, rice and corn production in China

Grain self-sufficiency is one of the most important agricultural policy goals in China. With only modest imports, China has succeeded in feeding 22% of the world's population on only 7% of its land. However, a high price has been paid for this enormous achievement. Increase in grain yields, in particular in rice, as the main source of production growth, relied heavily on intensive use of physical inputs and increasing intensity of farming systems. Soil degradation, water scarcity, and severe pollution were among the consequences as well as declining efficiency of fertilizer application. Using county-level panel data from 1980 to 2003 and graphical (GIS-based) analysis, this paper first looks at the spatial change of the major grain production across regions over the past two decades, towards the northern and northeastern provinces. The analysis is complemented by using a random panel data model, which underscores the significant influence of land availability, degree of urbanization, and government policy on grain production. Finally, this analysis addresses environmental stress which includes both soil degradation and water shortage. The latter is already severe in many of the traditional grain producing areas, but will now become a bigger problem in the “new” grain producing areas, as these have traditionally much less water resources. Hence, while the economic rational of the “grain shift” towards the northern and northeastern regions is understandable, its sustainability is not guaranteed.     

预处理-UASB-SBR联合工艺处理医药废水工程实例研究

河南某医药工厂废水CODCr含量高、pH值低、含盐量大、氨氮含量高。采用预处理＋UASB＋SBR联合工艺对其治理,工程调试结果表明,该工艺对CODCr、BOD5、含盐量、氨氮的去除率均在90%以上,出水水质满足《化学合成类制药工业废水排放标准》（GB21904-2008）中表2的要求。此类工艺调试运行过程要注意温度、进水水质对系统启动运行的影响,特别是UASB系统的启动运行的影响。启动初期不能过于强调处理效率,容积负荷要从低到高逐步增加,UASB初始容积负荷一般不超过0.6 kg/（m3.d）。