Pesticide contamination profiles of water, sediment and aquatic organisms in the effluent of Gaobeidian wastewater treatment plant

Organochlorine pesticides (OCPs, including DDT, HCH and HCB) and six indicator polychlorinated biphenyls (PCB 28, 52, 101, 138, 153, and 180) were measured in water, sediment, zooplankton, fish and Chinese softshell turtle (Pelodiscus sinensis) from Gaobeidian Lake, which is located in the effluent of Gaobeidian wastewater treatment plant (WWTP) in Beijing, China. DDTs were dominant except for in water. In water, the concentrations of DDTs (6.22 ng l(-1)) and HCHs (18.0 ng l(-1)) were less than the limits (l000 ng l(-1) for DDTs and 5000 ng l(-1) for HCHs). However, PCBs concentration (20.8 ng l(-1)) exceeded the limit (14 ng l(-1)) suggested by the United States Environmental Protection Agency (USEPA). The high ratio of p,p'-DDT/DDTs (0.80) in water suggested that DDTs had recently been discharged into the ambient environment despite a longtime ban in China. For fish and Pelodiscus sinensis, the accumulation patterns of OCPs and PCBs were different in muscle and liver. And HCB and PCB 153 were significant different in different species (p<0.05). PCBs were dominated by PCB 52 in zooplankton, but by PCB 138 and 153 in Pelodiscus sinensis. The highest food web magnification factor (FWMF) was 4.83 for p,p'-DDT and the second highest was 4.36 for PCB 101 in Gaobeidian Lake. As compared with the other studies, biomagnification in the present study was not obvious. Trophic levels and age were two important factors that might contribute to the bioaccumulation in the present study.     

模拟酸雨作用下红壤中CU2+的释放动力学

利用土柱研究了模拟酸雨淋溶下红壤中铜离子的释放动力学 .结果表明 :铜离子的累积释放量随时间的延长迅速增加 ,2 4h后基本达到平衡 ,48h后铜离子的释放明显受酸雨pH值的影响 ,pH >3 5时铜离子的释放规律依然相同 ,但pH 2 5时释放量却再次增加 .该过程可分为快速释放阶段和准平衡阶段 ,可用修正的Elovich方程和双常数速率方程来描述 ,且修正的Elovich方程更优     

稀土元素在水体食物链生物中迁移的摸拟研究

本文用动态和静态摸拟系统分别研究了稀土元素在小球藻-大型溞-鲤鱼食物链生物上的迁移。结果表明:水生生物对稀土的生物积累作用有从水体直接摄取和从食物间接摄取两种方式,但稀土元素在该食物链上无生物放大作用,生物体中积累的稀土量和水环境中残余的稀土浓度从轻稀土向重稀土递减,稀土元素在水环境中迁移的最重要形式可能是物理-化学迁移。     

Working mechanism and experimental study of dual-diameter and bi-speed composite drilling tool

ABSTRACT

As oil and gas production gradually shifts to deep and ultra-deep formations, the pressure and complexity of stratum is increased and drilling efficiency is decreased. Based on this, a Dual-diameter and bi-speed composite drilling method that can realize the different depth, diameter, and rotate speed coupling using only hole-bottom power is proposed in this paper. And a Dual-diameter and bi-speed composite drilling tool is designed, processed, and carried out to complete the field experiment. The tool is connected by a two-stage screw to make the rotate speed of a pilot bit higher than that of the reaming bit to increase the rate of penetration. And a concave bottom hole is formed so that the ground stress is released and the drillability of rock is lifted. Based on the introduction of the speed-up mechanism of the tool, the numerical analysis of the drilling performance of the tool with different diameter ratios and rotate-velocity combinations is completed. The experimental data showed that the Dual-diameter and bi-speed composite drilling method can obviously increase the rate of penetration and drilling efficiency, and also help to reduce the risk of stick-slip and prolong the service life of the drill bit.     

Improved overall water splitting for hydrogen production on aluminium-doped SrTiO3 photocatalyst via tuned surface band bending

Environmental Chemistry Letters - Future carbon neutrality and the energy crisis are calling for advanced methods to produce sustainable fuels such as hydrogen production by photocatalytic water...     

蒽醌染料及中间体脱色优势菌的特性研究和基因定位

本文对分离到的两株蒽醌染料脱色优势菌的脱色能力及其基因定位进行了研究,结果表明,ＮＤ１,ＮＤ２均能有效脱除活性艳蓝ＫＮ－Ｒ及溴氨酸的色度;两株优势菌均含有质粒,其降解染料的能力是由质粒控制的;并考察了不同碳源、氧、温度、ｐＨ值等理化因素对菌株降解染料的影响。     

蒽醌染料及其中间体絮凝菌的特性

本文研究所分离到的真菌ＮＸ１对蒽醌染料ＫＮＲ及其中间体溴氨酸的作用,并考察营养条件、体系ＰＨ等对ＮＸ１的生长及絮凝作用的影响,结果表明,ＮＺ１及溴氨酸有很好的絮絮凝效果,对ＰＨ的适应范围广,最佳碳、氮源分别为蔗粮主尿素。     

燃煤锅炉除尘脱硫技术应用研究

通过对江汉油田现有锅炉及烟气治理状况的调查,分析找出存在的问题是：设备腐蚀严重及现有设备脱硫效率低。针对这种情况进行了新技术开发,克服现有装置的缺点。简述了技术原理及主要装置（喷雾脱硫塔与湿式除尘器）和工艺流程：吸收剂制备系统、烟气净化系统及废渣排出系统;对此技术的实验表明：外排烟气中烟尘浓度为１５２ｍｇ／ｍ３,ＳＯ２浓度为１４２ｍｇ／ｍ３,脱除效率分别达到９６．５９％和８０．０２％,达到预期效果     

长江(万州段)水体溶解性有机物的荧光光谱分析

按照河床形态、水文条件、排污口分布、支流状况等特点从长江万州段及长江支流苎溪河选取8个断面进行采样,对水样中溶解性有机物(DOM)的荧光光谱特征进行了分析和研究.利用日立F-4500荧光分光光度计对长江水、普通自来水和纯水在紫外光激励下产生的荧光光谱及其特性进行了比较研究.同时,研究了不同水样、不同取样点的水体DOM的荧光特性和三维荧光光谱图.结果表明:长江水在波长290 nm左右的紫外光激励下能产生较强的荧光.荧光峰是350～550 nm范围的宽谱峰,荧光峰值波长在450 nm左右.但是不同取样点水样的荧光峰强度明显有差异,在4号、5号、2号取样点的水样荧光强度明显高于其他取样点,这与采样点附近污染源排放有明显的关系.该研究方法可作为鉴别水质污染的一种有效的手段.     

Fe0-厌氧微生物体系处理活性艳红X-3B的试验研究

采用间歇式摇床试验,研究了葡萄糖共基质条件下Fe0-厌氧微生物体系中Fe0投加量、pH值、染料初始浓度对活性艳红X-3B模拟废水脱色率的影响,比较了Fe0-厌氧微生物、纯厌氧微生物及纯Fe03种体系中废水的脱色效果.结果表明:Fe0-厌氧微生物体系中初始浓度(50～500 mg/L)对活性艳红X-3B的脱色率影响不大;而Fe0投加量、pH值存在一个最佳范围;当Fe0投加量为260 mg/L,pH值为6.0,污泥浓度为0.35 g VSS/L,停留时间约为30 h时,体系中活性艳红X-3B的脱色率可达90%左右,比相同试验条件下纯Fe0、纯厌氧微生物体系达到此脱色率所需时间分别缩短了约1/2、7/10.在Fe0-厌氧微生物体系中,由紫外可见分光光度分析可推测活性艳红X-3B的脱色机理主要是其偶氮键发生断裂,生成苯胺和萘类物质,而且苯胺和萘类物质能得到进一步降解.