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61.
豆制品加工废水有机物和悬浮物浓度较高,水量及水质波动大,且容易发酸发臭。浙江某豆制品生产企业采用化学沉淀+SBR生化工艺对废水进行处理,出水水质达到《污水综合排放标准》GB8978-1996三级标准。该工艺操作简便,运行稳定,处理效率高,适合中小规模豆制品企业废水的处理。  相似文献   
62.
雅砻江流域是我国水电开发的重点区域之一,在全球气候变化背景下探究流域干湿时空演变规律有利于合理规划和充分利用水资源,为流域内农业生产活动提供科学指导。基于1981~2017年雅砻江流域内及周边16个气象站月气象数据,采用Penman-Monteith(PM)公式计算各站逐月潜在蒸散量ET0,基于气象站降水校正CHIRPS卫星降水产品,从而获得更高空间分辨率的降水数据,以此计算标准化降水蒸散SPEI指数,采用云模型、Mann-Kendall(MK)趋势检验法分析流域年代际、年、季尺度的干湿时空分布特征与变化趋势。结果表明:(1)对CHIRPS卫星降水产品进行偏差校正不但提高了精度,而且能够获得更高空间分辨率的降水;(2)流域春季呈湿润化趋势,其余时间尺度均呈现干旱化趋势,以冬季干旱化速率最快。年尺度下干湿变化不均匀度的稳定性最差,秋季稳定性相对最好。春、冬两季SPEI空间分布的不均匀度弱于时间分布;(3)同一时间尺度下的流域各级别干湿相对面积近似呈正态分布,流域干湿变化趋势空间分布差异较大;(4)流域各级别干旱与湿润高发区无明显区域分布规律,发生干旱与湿润的最高频率在20%左右,且随着干湿程度的加重,频率变化范围逐渐缩小;(5)不同年代干湿频率差异较为显著,年平均干旱频率变化趋势为减-增-减,湿润频率变化趋势为增-减-减,湿润频率高值区呈现由下游向上游转移的趋势。  相似文献   
63.
European forestry is facing many challenges, including the need to adapt to climate change and an unprecedented increase in forest damage. We investigated these challenges in a Norway spruce-dominated mountain region in Central Europe. We used the model Sibyla to explore forest biomass production to the year 2100 under climate change and under two alternative management systems: the currently applied management (CM), which strives to actively improve the forest’s adaptive capacity, and no management (NM) as a reference. Because biodiversity is thought to have mostly positive effects on the adaptive capacity of forests and on the quality of ecosystem services, we explored how climate change and management affect indicators of biodiversity. We found a differential response across the elevation-climatic gradient, including a drought-induced decrease in biomass production over large areas. With CM, the support of non-spruce species and the projected improvement of their growth increased tree species diversity. The promotion of species with higher survival rates led to a decrease in forest damage relative to both the present conditions and NM. NM preserved the high density of over-matured spruce trees, which caused forest damage to increase. An abundance of dead wood and large standing trees, which can increase biodiversity, increased with NM. Our results suggest that commercial spruce forests, which are not actively adapted to climate change, tend to preserve their monospecific composition at a cost of increased forest damage. The persisting high rates of damage along with the adverse effects of climate change make the prospects of such forests uncertain.  相似文献   
64.
蓝藻水华暴发已成为全球性生态环境问题。太湖作为流域重要的水源地,2007年蓝藻水华事件的暴发引起公众的高度关注。运用问卷调查法,研究无锡市区489名公众的太湖蓝藻水华生态风险感知特征及其主要影响因素。研究结果表明:蓝藻水华生态风险被公众知觉为总体风险是陌生和完全可控的;蓝藻水华暴发原因是陌生和不可控的,这是引起公众风险意识的主要因素。影响公众蓝藻水华生态风险感知水平的主要因素有媒体、信息和个体因素。报纸广播电视是主要的媒体因素。信息因素有灾害信息、灾害治理信息、政府防范措施信息。灾害治理信息的影响作用最大,其次是灾害信息和政府防范措施信息。不同性别、年龄段、教育程度、收入水平及职业的人群,对不同类别的风险信息关注程度不同,影响到个体风险偏好的不同。研究结果有助于决策者更全面地理解蓝藻水华风险的本质,开展风险沟通,针对不同特征的人群选择有效的风险管理方案。〖  相似文献   
65.
基于复杂系统建模的水管理政策研究进展   总被引:3,自引:0,他引:3  
基于Agent的建模方法(ABSS)通过自下而上的方式,考察系统中主体的不同状态和行为特征、主体与环境的作用、主体之间的作用,来表征系统的宏观特征,是进行复杂社会环境系统分析和政策研究的重要手段,在水资源、水环境管理系统中得到了有效的应用。本文在大量文献调研的基础上,讨论了ABSS建模方法的基本原理、主要特征、系统构成、分类方法和开发工具等特征,总结了其供水系统发展、水资源分配和流域水资源管理、农业土地和水资源利用、居民用水行为、农业污染控制及人类活动的水环境影响等方面的应用,分析了其在研究内容、研究方法、研究结果等方面的发展趋势,讨论了利用该方法研究我国水资源管理和水污染控制政策的必要性和重要性。  相似文献   
66.
中日韩循环经济政策比较研究   总被引:6,自引:0,他引:6  
在中国经济迅猛发展的同时,投资主导型的经济模式中环境保护要素的缺失导致我国工业化发展旱、中期的资源、能源约束、效率低下和浪费严重。在我国实施循环经济刻不容缓。循环经济政策是依据不同的社会、经济和环境条件而制定的。由于历史的原因,中日韩三国在地缘关系、政治传统、风俗习惯、文化教育等内在制度和外在制度彼此趋同,反映在循环经济政策的制定、执行上也有某些相似的地方。对三国循环经济的历史和现状进行比较研究,得出有益于我国的经验,无疑具有很重大的现实意义。采用制度变迁的基本理论作为指导,运用历史研究法、调查研究法等方法进行研究,对中日韩循环经济政策演变的历程进行系统梳理和比较,深入全面地考量其指导思想和举措的选择动机,系统广泛地从多方面研究中日韩循环经济政策。并将三者加以比较,以得出对我国循环经济的发展具有较强借鉴意义的经验,更好地推进循环经济在我国的发展。  相似文献   
67.
In recent years, poly (butylene adipate-co-terephthalate) (PBAT) has been widely used. However, PBAT-degrading bacteria have rarely been reported. PBAT-degrading bacteria were isolated from farmland soil and identified. The effects of growth factors on the degradation of PBAT and the lipase activity of PBAT-degrading bacteria were assessed. The degradation mechanism was analyzed using scanning electron microscopy, attenuated total reflection Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, X-ray diffraction, and liquid chromatography-mass spectrometry. The results showed that Stenotrophomonas sp. YCJ1 had a significant degrading effect on PBAT. Under certain conditions, the strain could secrete 10.53 U/mL of lipase activity and degrade 10.14 wt.% of PBAT films. The strain secreted lipase to catalyze the degradation of the ester bonds in PBAT, resulting in the production of degradation products such as terephthalic acid, 1,4-butanediol, and adipic acid. Furthermore, the degradation products could participate in the metabolism of YCJ1 as carbon sources to facilitate complete degradation of PBAT, indicating that the strain has potential value for the bioremediation of PBAT in the environment.  相似文献   
68.
Ten nitrated polycyclic aromatic hydrocarbons (nPAHs) and 4 oxygenated polycyclic aromatic hydrocarbons (oPAHs) in fine particulate matter (PM2.5) samples from Mount Tai were analyzed during summer (June to August), 2015. During the observation campaign, the mean concentration of total nPAHs and oPAHs was 31.62 pg/m3 and 0.15 ng/m3, respectively. Two of the monitored compounds, namely 9-nitro-anthracene (9N-ANT) (6.86 pg/m3) and 9-fluorenone (9FO) (0.05 ng/m3) were the predominant compounds of nPAHs and oPAHs, respectively. The potential source and long-range transportation of nPAHs and oPAHs were investigated by the positive matrix factorization (PMF) method and the potential source contribution function (PSCF) methods. The results revealed that biomass/coal burning, gasoline vehicle emission, diesel vehicle emission and secondary formation were the dominant sources of nPAHs and oPAHs, which were mainly from Henan province and Beijing-Tianjin-Hebei region and Bohai sea. The incremental life cancer risk (ILCR) values were calculated to evaluate the exposure risk of nPAHs and oPAHs for three group people (infant, children and adult), and the values of ILCR were 7.02 × 10?10, 3.49 × 10?9 and 1.41 × 10?8 for infant, children and adults, respectively. All these values were lower than the standard of EPA (Environmental Protection Agency) (<10?6), indicating acceptable health risk of nPAHs and oPAHs.  相似文献   
69.
Modified clay (MC), an effective material used for the emergency elimination of algal blooms, can rapidly reduce the biomass of harmful algal blooms (HABs) via flocculation. After that, MC can still control bloom population through indirect effects such as oxidative stress, which was initially proposed to be related to programmed cell death (PCD) at molecular level. To further study the MC induced cell death in residual bloom organisms, especially identifying PCD process, we studied the physiological state of the residual Prorocentrum donghaiense. The experimental results showed that flocculation changed the physiological state of the residual cells, as evidenced by growth inhibition and increased reactive oxygen species production. Moreover, this research provides biochemical and ultrastructural evidence showing that MC induces PCD in P. donghaiense. Nuclear changes were observed, and increased caspase-like activity, externalization of phosphatidylserine and DNA fragmentation were detected in MC-treated groups and quantified. And the mitochondrial apoptosis pathway was activated in both MC-treated groups. Besides, the features of MC-induced PCD in a unicellular organism were summarized and its concentration dependent manner was proved. All our preliminary results elucidate the mechanism through which MC can further control HABs by inducing PCD and suggest a promising application of PCD in bloom control.  相似文献   
70.
塑料浮选作为一种基于表面活性剂的废旧塑料分选技术,是解决废旧塑料环境污染的有效方法. 为深入考察塑料浮选过程中气泡的黏附行为及影响因素,运用高速摄影技术结合气泡黏附时间模型,对比分析纯水中气泡与亲/疏水材料的黏附效果,重点比较不同溶液〔纯水、鼠李糖脂和SDS(十二烷基硫酸钠)溶液〕中气泡与疏水材料的黏附时间变化,并探讨其影响机制. 结果表明:气泡在纯水中只与疏水材料发生黏附,表面活性剂及其浓度对气泡与疏水材料的黏附时间影响显著. 在c(鼠李糖脂)和c(SDS)(二者均为0.03 mmol/L)均较低的溶液中,气泡与疏水材料的黏附时间由纯水中的158 ms分别降至120和140 ms,而二者较高(10.00 mmol/L)时黏附时间分别增至1 134和338 ms. 基于黏附时间模型分析表明,黏附时间是气泡尺寸、接触角、溶液黏度及表面张力等参数的函数,通过控制这些参数可以调控气泡在目标塑料表面的黏附时间,实现浮选效率的优化.   相似文献   
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