A new method of inhibiting pollutant release from source water reservoir sediment by adding chemical stabilization agents combined with water-lifting aerator

A new method of adding chemical stabilization agents combined with water-lifting aerator can inhibit pollutant release from source water reservoir sediment effectively.     

Effect and its time lags of water level fluctuations in Three Gorges Reservoir on the macroinvertebrates in a tributary bay北大核心CSCD

In order to study how water level fluctuations (WLF) of reservoir influence the macroinvertebrate in tributary bay, we studied the effect of WLF of the Three Gorges Reservior on macroinvertebrate communities in Xiangxi Bay, and the time lags of such effect, based on the surveys in spring and summer from 2005 to 2010. In this research, WLF was represented by water level drawdown (WLD) and the sum of absolute values of rate of water level fluctuations (RWlf). Pearson correlation analysis was used to analyze the relationship between WLF and macroinvertebrates. No significant correlation was found between macroinvertebrates and sum of absolute values of RWLF, while WLD showed significant influence on some biotic parameters. In spring, WLD did not cause significant effect to macroinvertebrates (P > 0.05). In summer, however, the influence was significant, especially in the area of the downstream (XX01 - XX02) of the Xiangxi Bay (P < 0.05). The middle reach of the bay (XX05), located in the conjunction area between Xiangxi Bay and a secondary tributary of the TGR, was also affected significantly (P < 0.05). The relative abundance of Tubificidae declined with the increase of the WLF, while abundance of Chironomidae increased. The time lags of the influence to macroinvertebrates were about 15 days. This analysis indicated that WLF in the mainstream of the reservoir mainly influences the downstream of the tributary bay, and also affects the conjunction area of the secondary tributary. Chironomidae are more tolerant than Tubificidae in water-body with dramatic disturbance, therefore can be considered as the indicator of the effect of summer WLF on macroinvertebrates.     

我国北方小流域硫酸参与碳酸盐矿物化学风化过程研究

硫酸参与碳酸盐岩的风化机制及与区域碳循环的关系是全球气候变化研究的重要课题.选择我国北方小流域(沁河)为研究对象,结合水化学及溶解性无机碳碳同位素组成,通过化学计算法,分析了河水溶解性组分的来源及混入比例,验证了硫酸参与区域碳酸盐的风化过程.结果表明:河水阳离子以Ca2+和Mg2+为主,阴离子以HCO-3和SO2-4为主;沁河流域碳酸盐岩风化、大气输入及蒸发盐溶解对河水阳离子贡献较大,平均比例分别为48.5%、35.3%和14.1%,硅酸盐风化和人为输入贡献比例较小,平均比例分别为1.7%和0.6%;沁河流域碳酸盐类、硅酸盐类及蒸发盐类风化速率分别为8.41、0.07和2.43 t·km-2·a-1,碳酸盐和硅酸盐矿物风化CO2消耗量分别为1.43×105mol·km-2·a-1和0.03×105mol·km-2·a-1;沁河流域硫酸参与碳酸盐风化产生的CO2净释放量为0.63×105mol·km-2·a-1,小于我国南方喀斯特地区CO2净释放量,可能与不同的气候条件及硫化物赋存条件和含量等有关.     

深海工程装备阴极保护技术进展

综述了深海工程装备阴极保护参数、牺牲阳极材料以及阴极保护技术研究及应用现状,分析了深海压力、溶解氧、温度、流速等环境因素对阴极保护电位、电流密度判据,牺牲阳极性能影响,认为温度和流速是影响阴极保护电流密度的两个关键因素,而温度和压力交变是影响牺牲阳极性能的两个主要因素。最后讨论了深海工程装备阴极保护技术发展方向。     

长沙市敢胜垸污水处理厂深度处理工艺的筛选研究

在二级生物处理工艺确定后,深度处理工艺的选择是保证整个工程出水水质的关键。过滤是污水深度处理工艺中最重要的工序,用以去除原水经沉淀后的残留絮体和杂质,具体依据出水效果、处理效率、投资成本和占地等各方面,确定采用深床过滤工艺。从整体优化的角度出发,结合设计规模,进水水质特征和出水水质要求以及当地的实际条件和要求,选择切实可行且经济合理的深度处理工艺方案,是实现整个长沙市敢胜垸污水处理厂最佳工艺方案的保障。     

南京建筑废弃泥浆絮凝减容效果与经济性分析

以南京市建筑废弃泥浆为研究对象,分别投加聚合氯化铝(PAC)、聚合硫酸铁(PFS)和阳离子聚丙烯酰胺(CPAM)开展絮凝减容试验,分析絮凝剂在不同投加量下泥浆沉降、水质指标及泥浆体积和含水率等的变化。结果表明：上述3种絮凝剂对泥浆均有较好的絮凝沉降效果,调理后泥浆的沉降速度由快变慢直至稳定,尾水水质可达到《污水排入城镇下水道水质标准》（GB 31962—2015）排放标准。CPAM调理的泥浆沉降效果最优,经过20 min的沉降,泥浆可实现减容80%以上,相对于直接将泥浆外运处置的费用,对泥浆絮凝减容后外运可以降低83%的成本。     

基于响应曲面法的有效抽采半径多因素交互影响机制研究*

为探究钻孔有效抽采半径的关键影响因素及各因素间交互作用,构建应力应变-瓦斯吸附解吸耦合渗透率变化模型,采用COMSOL软件进行数值模拟,分析单一因素变化对钻孔有效抽采半径的影响,并通过Design-Expert软件设计响应曲面试验,分析多因素交互作用对钻孔有效抽采半径变化的影响机制,获得有效抽采半径对多因素交互影响的响应曲面模型。研究结果表明:不同因素对钻孔有效抽采半径影响的显著性顺序为:煤层初始渗透率、原始瓦斯压力、抽采时间,煤层初始渗透率和抽采时间与有效抽采半径呈正相关关系,原始瓦斯压力与有效抽采半径呈负相关。1个影响因素的变化会影响其他因素对有效抽采半径的影响,煤层初始渗透率能够放大其他因素对有效抽采半径的影响,而原始瓦斯压力则会降低其他因素对有效抽采半径的影响。     

聚合氯化铁在微絮凝-深床过滤工艺中的应用

以聚铝(PAC)为参照比较研究了聚合氯化铁(PFC)在微絮凝深床过滤工艺中的应用效果.结果表明PFC投药量少(Fe:Al=3:5),其水头滤程可达63h,周期产水率可达1504m³/m²,而PAC的水头滤程为53h,周期产水率为1266 m³/m²;PFC表现出利于延长运行周期,提高产水率等优势.通过截污机理研究表明,PFC具有形成絮体快,与滤料作用迅速,脱水性能好等特点,与PAC相比PFC更适用于微絮凝-深床过滤工艺.     

煤巷掘进跨步预抽煤层瓦斯技术研究与应用

在采取瓦斯抽采安全技术措施情况下,针对煤巷掘进难以实现煤层的边掘边抽问题,提出煤巷掘进跨步预抽煤层瓦斯的方法。该方法利用钻场抽采孔在始端汇集末端发散的分布特点,通过钻场沿煤巷掘进方向的前后错位及钻孔布置的优化设计,实现钻孔在工作面前方煤体密集段与分散段的交错重叠,保障煤巷掘进控制区煤体瓦斯的无死角连续抽采及煤巷的持续掘进。现场试验表明:该技术在掘进面前方煤体具有较好的抽采效果,成功实现了煤巷的连续不间断掘进,在煤巷掘进期间未发生工作面瓦斯涌出事故及煤与瓦斯突出征兆。该技术为高瓦斯矿井及按突出矿井管理的煤层实现煤巷的边掘边抽提供了借鉴。