成都市危险废物现状调查及污染控制对策研究

本文在对成都市危险废物产生及污染控制状况进行调查分析的基础上,结合国内外危险废物管理经验,提出了成都市危险废物控制的对策及建议。     

市区主要交通路口机动车排气污染现状调查及防治对策

通过对主要交通路口汽车排气污染现状调查,证明交通路口是城市中空气质量最差地段,特别是对人体危害较火的总烃、一氧化碳、氮氧化物污染尤为严重;提出改善城区道路建设、改善燃料质量等防治措施。     

竹醋酸在堆肥中的应用

以秸杆、锯末和猪粪为原料,以竹醋酸为添加剂进行静态好氧堆肥试验,分析堆肥过程中温度、pH、有机质、TN等的变化情况,比较不同竹醋酸浓度对堆肥的促进作用。在对腐熟后堆肥的分析表明,适宜的竹醋酸浓度可以促进微生物的活性,缩短达到高温所需的时间;跟空白堆体相比,添加竹醋酸的堆体氮损失率降低10%。     

The Stream and Its Altered Valley: Integrating Landscape Ecology into Environmental Assessments of Agro-Ecosystems

Little is known about the importance of landscape and land cover to the implementation and performance of agricultural conservation projects designed to improve stream quality. In our study, we addressed the potential importance of landscape and land cover to conservation projects by measuring variation across 191 μ-basins (100–2400 ha) and integrating the observed variation into a study design aimed at determining the effectiveness of conservation projects. Our findings indicate that there are strong gradients across which landscape and land cover attributes vary. Land cover varied along a gradient of agricultural intensity, basin morphometry across gradients of stream closure and basin size, basin substrate was described by variation in drumlin formation, glacial landform type, and soil drainage, while agricultural conservation projects varied according to the level of project implementation. Correlation of these gradients found several associations between landscape and land cover, indicating that agricultural intensity was being constrained predominantly by drumlin formation and glacial landform type. Landscape and land cover did not appear to be determining factors in the implementation of conservation projects by land owners. Based on these findings we chose 32 μ-basins which represented the variability along each of the defined gradients for further study. We conclude that landscape scale variables demonstrate important variation and covariation that can and should be integrated into study designs for the assessment of streams and human activities affecting streams.     

新型溴系阻燃剂环境污染现状研究进展

新型溴系阻燃剂(NBFRs,novel brominated flame retardants)作为传统溴系阻燃剂的替代品已广泛应用于电子产品、纺织品、家具等商品中,随着这些商品的生产、使用和处置,NBFRs不可避免地释放到环境中,给环境和人体带来潜在的危害.部分NBFRs可通过摄食和呼吸作用进入人体对人体产生一定危害...     

An experimental-computational study of DPF soot capture and heat regeneration

ABSTRACT

A diesel particulate filter (DPF) can effectively reduce the exhaust emissions of particulate matter (PM) and meet emission regulations. We report herein an experimental-numerical study to investigate the soot capture and regeneration behavior in a commonly used DPF. Simulations are performed using the AVL FIRE software that considers a fairly detailed DPF model. The model is validated using measured pressure drop history during soot capture, and temperature history during regeneration from a parallel experimental study using a diesel engine equipped with a DPF. Then, a detailed numerical study is performed to examine the soot capture and heat regeneration processes, and characterize the effects of various parameters on these processes and on DPF performance. Results indicate that the pressure drop during soot loading can be reduced by increasing the CPSI (channels per square inch), minimizing the amount of residual soot in each regeneration cycle, and using moderate gas flow rates. The DPF regeneration performance is characterized in terms of the rates of temperature rise and soot oxidation. Results indicate that these rates are enhanced, as the oxygen content in the exhaust stream is increased to about 12%, the rate of thermal heating is moderately increased, and as the exhaust gas flow rate is increased. Thus, the regeneration efficiency can be significantly improving by optimizing these parameters.     

Tertiary treatment of municipal wastewater using isolated algal strains: treatment efficiency and value-added products recovery

ABSTRACT

Two microalgal strains (Chlorella sorokiniana, A&B,) grown optimally at pH 9 (A) and 7 (B) were isolated from a municipal wastewater treatment plant. These strains were used to check their efficacy for nutrients and organic carbon removal capacities from the tertiary wastewater. The strains were characterised using 18S rDNA sequencing method and both the strains closely related to Chlorella sorokiniana. Different inoculum doses (IDs) of both the strains were tried to check their efficacy on wastewater treatment. Due to the increase in the IDs, hydraulic retention time decreased from 6 d to 1?d. On an average, 12–100% of total kjeldahl nitrogen, 53–96% NO₃–N, and 59–92% PO₄–P, were removed. Despite the same growth environment, strain A with the highest ID (700?mg/L) showed the best performance in terms of overall organic carbon removal, nutrient removal, and value-added products recovery. Strain A showed an increase in carbohydrate and protein content by 42% and 13%, respectively. Both the strains showed luxury phosphorus uptake and found suitable for advanced wastewater treatment.     

基于不同指标无量纲化方法的岩爆预测模型优选

为研究不同指标无量纲化方法对岩爆等级预测模型精度的影响,提高岩爆预测准确率,选取应力系数、脆性系数和弹性能量指数作为预测指标。基于104组岩爆实例大样本数据,采用统一极差处理法、差异化极差处理法、平均化处理法和归一化处理法4种指标无量钢化方法,对预测指标的原始数据进行处理,建立不同的岩爆预测距离判别模型并进行工程实例应用。研究结果表明:基于平均化处理法的岩爆预测模型的回判准确率高达97.1%;对不同矿山、隧道和水电站的6个工程实例的预测结果符合实际情况,说明其是一种准确率高、方便实用的岩爆预测模型。     

高速公路交通救援资源派遣方法适用性研究

为降低高速公路交通事故人员伤亡和财产损失、提高指挥调度中心救援效率,将适合高速公路交通救援资源派遣的匈牙利法、直接成本法和机会成本法,分别从基于资源派遣方法的数学特征、高速公路交通救援点配置情况和交通事故救援实施3个方面对各方法的适用性进行研究,并结合指挥调度中心现有资源派遣实际,制定出交通救援资源派遣规则。以南京市周边高速公路网为例,根据适用条件选用合适的交通救援资源派遣方法和派遣规则,进行救援资源的派遣决策,为指挥调度中心高效地派遣交通救援资源提供了理论依据和合适方法。     

高等级公路的交通安全现状及对策

目前我国半数以上的公路交通事故都发生在高等级公路上,并且事故的损害后果严重。运用死亡比重指标分析近年全国交通事故统计资料和四川省部分高等级公路的交通事故案例,发现高等级公路的交通事故在形态、成因和气象条件等方面具有显著特征,为改善高等级公路的交通安全现状,需要在公路的交通分离、行车监控、行车视距、危险警示和护栏安全等方面采取更为有效的保障措施。