荧光光谱技术在堆肥腐熟度评价中的应用

高温好氧堆肥是世界各国资源化利用固体有机废弃物最重要的途径之一,堆肥腐熟度是评价堆肥过程及堆肥产品质量的重要尺度.荧光光谱(FS)技术具有诸多优点,目前已广泛应用于不同来源有机质结构特征的研究,其在堆肥腐熟度评价中具有广阔的应用前景.在分析了FS技术的原理及特点的基础上,从发射光谱、激发光谱、同步FS和三维FS方面详实综述了FS技术在有机固体废弃物堆肥物质转化及腐熟度评价中的应用原理及其国内外进展,并对FS技术在堆肥腐熟度评价中存在的问题及发展前景进行了评述.     

生活垃圾焚烧处理方式的生命周期评价

与填埋、堆肥处理相比,生活垃圾焚烧处理在减量化和资源化方面有着巨大的优势,在未来将成为大城市生活垃圾的主要处理方式。采用生命周期评价方法,对不同余热利用和尾气处理方式下的生活垃圾焚烧处理方案对环境的影响进行评价。结果表明,在尾气处理系统中,干法、湿法、半干法3种酸性气体处理方式中,湿法处理的环境影响潜值最小,但是其资源耗竭系数最大。添加SNCR脱氮系统可以在酸性气体净化基础上将环境影响潜值降低70%左右,而资源耗竭系数变化不大。在单纯供热、供电和热电联供3种余热利用方式中,单纯供电的热利用效率最低,直接供热的热利用效率最高。     

China’s Grain for Green policy and farm dynamics: simulating household land-use responses

Analyzing the interaction between environmental policies and farmers’ responses to them is an important dimension to understand regional agro-ecosystem sustainability. We examine land-use outcomes of perhaps the largest government-planned rural reforestation program in the history of humankind, China’s “Grain for Green” (GFG) policy from 1999 to 2006. Specifically, we simulate household responses to the GFG policy in Western China’s Shaanxi Province, a region experiencing acute climate and land change-related environmental degradation. We develop a “farmer group decision-making model” to simulate the probability of land-use change. Elevation, slope, and farm household characteristics emerge as key factors influencing farmers’ land-use decisions and subsequent land-use patterns. Land reversion and abandonment in the study area have been significantly affected by the GFG program. Policy recommendations suggest potential avenues to enhance the effectiveness of the GFG program and to improve the efficient use of under-used farmland. Results may help inform the Chinese government as it crafts policy guiding a coupled rural migration and reforestation program of unprecedented scale.     

PVDF/PMMA与PVDF/TPU共混膜抗污染性能研究及应用

观察新型五孔PVDF共混改性纤维膜SEM形貌特征,采用逐级通量法测定PVDF/PMMA和PVDF/TPU共混改性膜的临界通量,研究在次临界和超临界通量下A(PVDF/PMMA)与B(PVDF/TPU)2种管式膜组件的过滤和抗污染性能,并在次临界通量下处理地表水。结果表明,PVDF共混改性膜具有优良的微观结构,且膜B性能较好;膜A、B的临界通量分别为12 L/(m2.h)和10 L/(m2.h);膜组件B比膜组件A抗污染性能好。次临界通量下膜组件的运行比超临界通量下的稳定。与采用单独超滤处理某市地表水相比,2种膜组件采用混凝+超滤工艺的运行处理效果更好,且膜组件B比膜组件A处理效果佳。     

序批式生物膜反应器处理农村生活污水的填料对比研究

选用4种填料进行序批式生物膜反应器(SBBR)处理农村生活污水的研究,通过出水COD、NH4+-N等指标的测定以及生物膜的扫描电镜观察,考察了运用不同填料时SBBR的污染物去除情况和生物膜的长势,以期筛选出适用于农村生活污水处理的填料。结果表明,3#、4#SBBR(分别选用组合填料和碳素纤维填料)的DO、pH波动幅度均相对较小,比1#、2#SBBR(分别选用立体网状填料及海绵填料)更加稳定;4#SBBR的COD去除效果最好,水力停留时间仅需5h,3#SBBR的COD去除效果其次,所需水力停留时间为6h,而1#、2#SBBR在运行8h时也无法将COD完全消化;3#、4#SBBR出水的NH4+-N、TN去除效果均高于1#、2#SBBR;采用4种填料的SBBR的生物膜长势优劣情况为碳素纤维填料>组合填料>海绵填料>立体网状填料;碳素纤维填料及组合填料在受到进水负荷冲击后,能相对较快适应环境,且填料上的微生物活性较高,较适合运用于中国农村生活污水的处理。     

不同混合比牛粪玉米秸中温干发酵产沼性能

设置5组牛粪和玉米秸的混合物(干物质比为0∶1、1∶0、1∶1、1∶2、2∶1),研究其在中温35℃下干发酵产沼性能,以产沼性能最好实验组的实验数据为基础,对比研究了两类产气模型。研究结果显示:玉米秸与牛粪的混合干发酵运行效果较好;其中,牛粪和玉米秸干物质比为2∶1时产沼效果最好,产气量最高为81 209 mL,干物质产气率为0.312 m3/kg,整个发酵过程中产气量和甲烷的含量比较稳定,CH4含量最高达56.59%,总固体、挥发性固体的去除率相对较高,分别为26.11%和34.27%。一级动力学模型与多项式函数方程2个产气模型拟合检验结果显示,应用简单的多项式函数即可对产气情况进行相对准确的预测。     

Simulation of Biomass Accumulation Pattern in Vapor-Phase Biofilters

Existence of inert biomass and its impact on biomass accumulation patterns and biofilter performance were investigated. Four biofilters were set up in parallel to treat gaseous toluene. Each biofilter operated under different inlet toluene loadings for 100 days. Two microbial growth models, one with an inert biomass assumption and the other without, were established and compared. Results from the model with the inert biomass assumption showed better agreement with the experimental data than those based on the model without the inert biomass assumption thus verifying that inert biomass accumulation cannot be ignored in the long-term operation of biofilters. According to the model with an inert biomass assumption, the ratio of active biomass to total biomass will decrease and the inert biomass will become dominant in total biomass after a period of time. Filter bed structure simulation results showed that the void fraction is more sensitive to biomass accumulation than the specific surface area. The final void fraction of the biofilters with the highest inlet toluene loading is only 67% of its initial level while the final specific surface area is 82%. Identification and quantification of inert biomass will give a better understanding of biomass accumulation in biofilters and will result in a more exact simulation of biomass change during long-term operations. Results also indicate that an ideal biomass control technique should be able to remove most inert biomass while simultaneously preserving as much active biomass as possible.     

砷污染与生态环境的关系

砷为广泛存在于自然界中的一种元素,在环境中表现出复杂的地球化学性质,不同形态的砷在大气、土壤及水体中的迁移和富集受许多物理化学因素的制约,并产生毒害程度不同的环境效应。总结砷的来源、其在不同环境介质中的存在状态及砷污染对生态环境的影响,提出应在了解不同介质环境中砷的赋存状态后,采用不同的治理方法有效地去除砷,以最大程度地降低砷对人体健康及生态环境造成的危害。     

某油田加油站作业人员职业健康状况分析

从加油站作业人员接触的主要职业病危害因素入手,重点对加油站油气防护设施、个人防护用品、工作制度等进行职业卫生现场调查,同时,根据对作业人员职业性健康检查结果和作业场所空气中汽油及苯的浓度检测结果,分析加油站作业人员的健康状况和长期接触成品汽油对作业人员健康的影响。结果表明,加油站人员作业过程中接触的汽油及苯系物对员工健康可能构成危害,但若加强职业健康监护及个体防护,就能有效预防汽油及苯系物所带来的职业危害。