微塑料诱导下污泥造粒潜能变化及微生物富集特征

微塑料(MPs)是污水处理厂中普遍检出的新兴污染物之一,目前研究主要集中于传统污水处理系统的污染水平及分布特征,但有关微塑料暴露对污泥颗粒化过程的研究鲜见报道.为探究微塑料对污泥颗粒化的诱导影响,选用环境中广泛检出的聚对苯二甲酸乙二醇酯微塑料(PET-MPs)作为研究对象,通过微塑料暴露试验研究PET-MPs对污泥造粒过程中系统潜能、胞外聚合物(EPS)组成和菌群富集特征的影响.结果表明,PET-MPs暴露显著加快污泥颗粒化进程,同时以蛋白质(PN)为主导的EPS含量上升会增强污泥表面疏水性,造粒速度和EPS分泌量与暴露粒径成正比,微塑料和EPS协同促进颗粒污泥的形成.然而微塑料持续暴露会导致系统除污性能恶化,250μm PET-MPs暴露下亚硝酸盐氮积累的负面影响最严重,浓度高达(5.08±0.24)mg·L^-1.高通量测序结果进一步表明,变形菌门(Proteobacteria)和拟杆菌门(Bacteroidota)是促进颗粒污泥形成的主要优势门;红环菌科(Rhodocyclaceae)、鞘氨醇杆菌科(Sphingomonadaceae)、黄杆菌科(Flavob...     

用“条件”水分平衡法分析湖北省干旱的时空分布规律

从“条件”水分平衡角度和农业生产实际情况出发，提出了一个综合考虑水分盈亏和同期作物需水量的干旱指标，并用此指标分析了湖北省１９６１－１９９０年３０年来的主要干旱类型的时空分布规律及对农业生产的影响。     

Quality assured measurements of animal building emissions: gas concentrations

Comprehensive field studies were initiated in 2002 to measure emissions of ammonia (NH3), hydrogen sulfide (H2S), carbon dioxide (CO2), methane (CH4), nonmethane hydrocarbons (NMHC), particulate matter <10 microm in diameter, and total suspended particulate from swine and poultry production buildings in the United States. This paper focuses on the quasicontinuous gas concentration measurement at multiple locations among paired barns in seven states. Documented principles, used in air pollution monitoring at industrial sources, were applied in developing quality assurance (QA) project plans for these studies. Air was sampled from multiple locations with each gas analyzed with one high quality commercial gas analyzer that was located in an environmentally controlled on-farm instrument shelter. A nominal 4 L/min gas sampling system was designed and constructed with Teflon wetted surfaces, bypass pumping, and sample line flow and pressure sensors. Three-way solenoids were used to automatically switch between multiple gas sampling lines with > or =10 min sampling intervals. Inside and outside gas sampling probes were between 10 and 115 m away from the analyzers. Analyzers used chemiluminescence, fluorescence, photoacoustic infrared, and photoionization detectors for NH3, H2S, CO2, CH4, and NMHC, respectively. Data were collected using personal computer-based data acquisition hardware and software. This paper discusses the methodology of gas concentration measurements and the unique challenges that livestock barns pose for achieving desired accuracy and precision, data representativeness, comparability and completeness, and instrument calibration and maintenance.     

Conservation genetics of <Emphasis Type="Italic">Lumnitzera littorea</Emphasis> (Combretaceae), an endangered mangrove,from the Indo-West Pacific

Mangrove forests, with their ecological significance and economic benefits, are vital inter-tidal wetland ecosystems. Lumnitzera littorea (Combreataceae) is a non-viviparous mangrove distributed in tropical Asia and North Australia. Due to natural and human impacts, populations of this species have been isolated, fragmented, and highly disturbed. In China, L. littorea is an endangered species, restricted to small regions of Hainan Island. The genetic composition of five populations of this species from the Indo-West Pacific (South China, Malay Peninsula, Sri Lanka, North Australia) was assessed using inter simple sequence repeat (ISSR) makers. At the species level, expected mean heterozygosity (He) was 0.240 with 75.6% of loci polymorphic (P). However, genetic variation was much lower at the population level (P = 37.1%, He = 0.118). A high coefficient of gene differentiation (Gst = 0.515) and low level of gene flow (Nm = 0.470) indicated significant genetic differentiation among populations. AMOVA also indicated that more than half the total variation (58.4%) was partitioned among populations. The high degree of differentiation observed among populations emphasizes the need for appropriate conservation measures that incorporate additional populations into protected areas, and achieve the restoration of separate, degraded populations.     

环境分析化学发展战略研究

环境分析化学是环境化学的一个重要分支.本文报导环境分析化学的研究领域,对象,国内外研究工作的发展趋势以及环境分析方法和环境监测仪器等。近年来,在污染物的超痕量分析、环境标准参考物的制备以及环境分析监测技术自动化方面都有较大的进展,对推动研究污染物的来源、毒性和含量,为最终控制和改造环境起到了推动作用,环境科学的发展在一定程度上依赖于环境分析化学所取得的成就。 在研究国内外工作动向的基础上,我们提出了环境分析化学的中近期研究方向,其中包括有机污染物和元素化学形态定值的环境标准参考物质、无机毒物的形态分析、分析技术的联用,有毒污染物的系统分析、我国优先监测污染物名单的制定、新型采样器,以及监测技术自动化研究等方面,以供从事这方面工作的领导和科研人员参考。     

有机磷农药废水碱性水解生物处理技术

本文报道了碱性水解和生物氧化两步法,处理有机磷农药-乐果、甲胺磷生产废水的研究结果.废水经碱性水解后,COD和有机磷浓度基本不变,但可生化性有明显改善.在遵循常规生物处理必须满足的条件下,碱性废水进一步用间歇或连续活性污泥法处理.COD去除率90%左右,有机磷去除率85%以上,有机磷含量以毒性磷计小于0.5mg/L.深入考察了碱解剂种类、水溶液的pH和温度等各种因素对碱性水解的影响,结果表明:NaOH作碱解剂时的碱解速率比Ca(OH),提高28%;碱解速率随pH和温度的升高而增大,pH每增加一个单位,碱解速率增加2～11倍;温度每升高10℃,碱解速率增加2～5倍.     

完善土地利用总体规划有利于政府宏观管理

在社会主义市场经济体制的建立与发展的条件下,土地使用制度改革的日益深化,以及土地可持续利用日益被高度重视的新形势下,土地利用总体规划作为政府对土地利用实行宏观调控的有效手段,在规划修编时必须重点对规划目标、科学测算、用地平衡和规划协调等几个方面作进一步深入研究。同时,要通过切实可行的法律、行政的政策和措施,予以必要保障。     

祁连山空中云水资源开发利用效益预测与评估

利用社会效益、经济效益和生态效益3 个方面25 项指标, 建立了空中云水资源开发利用综 合效益的评价体系。同时对祁连山区人工增雨对径流的影响作了预估, 在此基础上, 对祁连山云水 资源开发利用后山前走廊各流域水资源状况及社会经济状况进行了合理的预测。最后, 选用其中 11 项指标, 并运用层次分析法对祁连山空中云水资源开发利用效益进行了评价。结果表明: 祁连山 空中云水资源开发利用对山前走廊的社会、经济、生态等效益均显著增加, 祁连山区通过人工增雨, 降水增加10%时, 河西地区综合效益将提高5.3%, 降水增加20%时, 综合效益提高12.5%。     

Loading estimates of lead, copper, cadmium, and zinc in urban runoff from specific sources

Urban stormwater runoff is being recognized as a substantial source of pollutants to receiving waters. A number of investigators have found significant levels of metals in runoff from urban areas, especially in highway runoff. As an initiatory study, this work estimates lead, copper, cadmium, and zinc loadings from various sources in a developed area utilizing information available in the literature, in conjunction with controlled experimental and sampling investigations. Specific sources examined include building siding and roofs; automobile brakes, tires, and oil leakage; and wet and dry atmospheric deposition. Important sources identified are building siding for all four metals, vehicle brake emissions for copper and tire wear for zinc. Atmospheric deposition is an important source for cadmium, copper, and lead. Loadings and source distributions depend on building and automobile density assumptions and the type of materials present in the area examined. Identified important sources are targeted for future comprehensive mechanistic studies. Improved information on the metal release and distributions from the specific sources, along with detailed characterization of watershed areas will allow refinements in the predictions.