Treatment of sewage sludge using electrokinetic geosynthetics

The treatment and disposal of sewage sludge is one of the most problematical issues affecting wastewater treatment in the developed world. The traditional outlets for sewage sludge are to spread it on agricultural land, or to form a cake for deposit to landfill or incineration. In order to create a sludge cake, water must be removed. Existing dewatering technology based on pressure can only remove a very limited amount of this water because of the way in which water is bound to the sludge particles or flocs. Several researchers have shown that electrokinetic dewatering of sludge is more efficient than conventional hydraulically driven methods. This involves the application of a dc voltage across the sludge, driving water under an electrical gradient from positive (anode) electrode to negative (cathode) electrode. However, there have been several reasons why this technique has not been adopted in practice, not least because the, normally metallic, anode rapidly dissolves due to the acidic environment created by the electrolysis of water. This paper will describe experimentation using electrokinetic geosynthetics (EKG): polymer-based materials containing conducting elements. These have been used to minimise the problem of electrode corrosion and create a sludge treatment system that can produce dry solids contents in excess of 30%. It will suggest different options for the treatment of sludges both in situ in sludge lagoons and windrows, and ex situ as a treatment process.     

堆积型铝土矿采场土壤对雨季采矿的影响研究

堆积型铝土矿床开采工作面大，雨季采场土壤的性质对生产影响严重。根据试验及现场测试获得的采场土壤物理力学性质及其在雨季的变化情况，着重分析了采场土壤经雨水浸泡后其物理力学性质的变化机理和雨季对采矿运输设备运行及采场作业的影响，提出了针对雨季采矿的相应对策。     

YS型盘式真空过滤机的研制与实践

介绍了YS型盘式真空过滤机的技术性能，分析了YS型盘式真空过滤机的技术特点。通过对YS型盘式真空过滤机与陶瓷过滤机在鞍钢东鞍山烧结厂对比工业试验分析发现，YS型盘式真空过滤机具有良好的过滤性能和过滤效果。     

陶瓷过滤机在永平铜矿的工业试验及生产应用

永平铜矿针对硫精矿水分偏高的问题，决定采用HTG-45型陶瓷过滤机进行脱水。工业试验和1年多的生产应用表明：该过滤机具有运行稳定、可靠、过滤效率高、滤饼水分低、节能等优点，使硫精矿平均水分降低到10.22%，降低了脱水生产成本，具有显著经济效益和社会效益。     

我国难滤铁精矿的气压压滤试验研究

介绍了酒钢选矿厂焙烧磁选铁精矿，东鞍山烧结厂浮选铁精矿和梅山铁矿浮硫后铁精矿采用气压压滤工艺进行实验室研究、半工业试验和工业试验的结果，并提出了几点看法，认为气压压滤工艺是解决我国一些铁精矿过滤难的重要途径。     

安庆铜矿充填模拟脱水试验

在塑料波纹管上粘凿脱水孔，外包膜水滤布的脱水方式是解决高大采场嗣后一次尾砂胶结充填料浆脱水的有效途径，在地表进行模拟脱水试验时，塑料波纹管脱水孔孔网参数和１１种滤布的脱水性能进行对比后，确定选择φ９ｍｍ呈梅花形布置的脱水孔和１００目尼龙滤布进行采场充填脱水。     

国外脱水设备的研究与进展

本文系统阐述了国外脱水设备的现状和最新研究方向，以引起国内选矿工作者的重视和借鉴。     

Influence of vacuum pressure,pH, and potential gradient on the vacuum electro-osmosis dewatering of drinking water treatment sludge

This paper describes research that evaluated the influence of vacuum pressure, pH, and potential gradient on the vacuum electro-osmosis dewatering (VEOD) of drinking water treatment sludge (DWTS). In the first phase of the VEOD process, a vacuum pressure of ?0.05 MPa was applied alone to DWTS for 30 min, removing almost all free water and part of pore water. In phase two, electro-osmosis was applied in combination with intermittent vacuum filtration, further reducing pore water and surface adhesion water in DWTS. However, statistical analysis indicated that the optimum dewatering parameter values were vacuum pressure at ?0.06 MPa, pH at 6.2, and potential gradient at 2.5 V/cm, which resulted in a relevant energy consumption of 0.35 kW.h/kg removed water.     

Influence of Electric Field Application with Decreasing One Sided Area of Electrodes on Electro-Osmotic Dewatering

Electro-osmotic dewatering is typically operated under an electric field of direct current condition. In the process of electro-osmotic dewatering, water content in part of the material near the electrode opposite to the drainage surface is locally reduced, resulting in an increase of electrical contact resistance between the electrode and the material being dewatered. Then the efficiency of the electro-osmotic dewatering process is reduced remarkably.

In order to improve the performance of electro-osmotic dewatering, it is supposed that a porous plate-type electrode used generally opposite to the drainage surface may be replaced to several rod-type electrodes, which are inserted into the material with dewatering. Using rod-type electrodes, the area of those electrodes becomes smaller than the plate-type electrode.

From this point of view, electro-osmotic dewatering was experimentally investigated by decreasing one-sided area of electrodes, namely the area of the plate-type electrode opposite to the drainage surface, and the influence of such an electric field application on improvement of the dewatering process is discussed in this article.     

大水金属矿山防治水综合技术方法的研究

阐述了国内大水金属矿山防治水技术的现状,论述了疏干排水、地面矿区帷幕注浆和井下近矿体帷幕注浆3种最常用防治水技术方法,并指出帷幕注浆是大水金属矿山防治水的发展方向,近矿体帷幕注浆将得到进一步推广应用。