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。     

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.     

Sulfate-reducing bacterial community shifts in response to acid mine drainage in the sediment of the Hengshi watershed,South China

Environmental Science and Pollution Research - Sulfate-reducing bacteria (SRB) are an attractive option for treating acid mine drainage (AMD) and are considered to be of great significance in the...     

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     

基于STAMP模型的电网企业事故风险控制模型

事故预防和风险控制理论模型对于指导企业开展安全工作具有重要作用,智能化、信息化、自动化对电网企业的事故预防和风险控制工作提出新的挑战,因此有必要对电网企业进行事故风险控制模型研究.本文基于系统安全和风险控制理论与STAMP模型,结合我国电网企业的特点与安全现状,对电网企业事故风险控制模型进行研究,构建了基于STAMP模...