Membrane fouling controlled by coagulation/adsorption during direct sewage membrane filtration (DSMF) for organic matter concentration

Unlike the role of the membrane in a membrane bioreactor, which is designed to replace a sediment tank, direct sewage membrane filtration (DSMF), with the goal of concentrating organic matters, is proposed as a pretreatment process in a novel sewage treatment concept. The concept of membrane-based pretreatment is proposed to divide raw sewage into a concentrated part retaining most organics and a filtered part with less pollutant remaining, so that energy recovery and water reuse, respectively, could be realized by post-treatment. A pilot-scale experiment was carried out to verify the feasibility of coagulant/adsorbent addition for membrane fouling control, which has been the main issue during this DSMF process. The results showed that continuous coagulant addition successfully slowed down the increase in filtration resistance, with the resistance maintained below 1.0 × 10¹³ m^− 1 in the first 70 hr before a jump occurred. Furthermore, the adsorbent addition contributed to retarding the occurrence of the filtration resistance jump, achieving simultaneous fouling control and chemical oxygen demand (COD) concentration improvement. The final concentrated COD amounted to 7500 mg/L after 6 days of operation.     

我国空气净化器标准体系建设的思考

本文总结、综述了我国现有的空气净化器相关标准,包括直接、间接和引用相关标准,分析了现有标准体系的特点和存在的问题,对我国空气净化器标准体系的建设和完善,提出了一些制修订建议,希望借此建议推动规范空气净化器产品市场,从而更好地为消费者服务。     

施工现场临时用电管理

据统计,全国施工现场临时用电发生触电死亡事故占事故总数8%左右,仅上海市2003年施工现场临时用电发生触电死亡事故就占事故总数的15.4%,触电事故已是建设工程发生事故的主要因素之一.……     

重大危险源辨识标准修订的探讨

20世纪 70年代以来 ,重大工业事故不断发生,给人们正常的生产、生活造成巨大的威胁和伤害,从而引起国际社会的广泛重视 ,预防重大工业事故成为各国社会、经济和技术发展的重点研究对象之一.     

Overview on LFG projects in China

Since the first landfill gas (LFG) power plant in China was built in 1998, by now more than 10 years have passed. In this period the LFG utilization process has progressed greatly in China. An overall review of the process is presented in this paper, which includes the background of policies, the information about the approval procedure of LFG projects, and the theoretical methods used to estimate the amount of LFG’s generation. Detailed analysis on the project practice, such as LFG collection techniques, LFG utilization condition in China, is made. According to statistic data, before the end of 2008, 26 LFG power projects have been built and put into operation with total power capacity around 56.8 MW, and 2.234 million tons of carbon dioxide equivalent abatement has been achieved annually by all of these LFG projects. The future of LFG industry in China is expected that there is still considerable developing space for LFG utilization in the near coming years, however after 2012, the progress speed may slow down because of some adverse aspects, such as available landfill resource becomes scarce, new laws implemented in China might exclude Chinese landfills from future CDM activities, etc.     

Oxidation of industrial dyeing wastewater by supercritical water oxidation in transpiring-wall reactor.

Industrial dyeing wastewater was oxidized in supercritical water in a transpiring-wall reactor, using hydrogen peroxide as an oxidant. Experiments were performed at 595 to 704 K and 18 to 30 MPa, with an oxidant dosage ratio ranging from 0.6 to 2.0. A chemical oxygen demand (COD) removal of more than 98.4% was achieved at 704 K and 28 MPa, with a retention time less than 35 seconds, which increased with the temperature, pressure, and oxidant. A modified first-order rate expression was regressed from experimental data, taking into account the influence of induction time. The resulting pre-exponential factor, A, and activation energy, Ea, were 1.07 seconds(-1) and 12.12 kJ x mol(-1), respectively, while the reaction order for feed wastewater (based on COD) and oxidant were assumed to be 1 and 0, respectively. Gas chromatography/mass spectrometry analysis for effluents indicated that carbon dioxide, carbon monoxide, and nitrogen were the main reaction products, and phenol; benzenecarboxylic acid; 1, 2-benzenedicarboxylic acid; and isoquinoline were detected as intermediates.     

土壤中石油类的测定方法

采用四氯化碳提取硅酸镁吸附非分散红外法测定土壤中石油类,该方法操作步骤简单,分析时间较短,测定方法回收率在９１～９６％之间,方法的精密度满足监测分析的要求。     

云南普洱地区中学生认知与响应地震灾害特点的初步研究——以2007宁洱6.4级地震灾害为例

2007年云南宁洱6.4级地震发生4个月后,以该次地震不同烈度区内的4所中学的学生为调查对象,借助问卷调查的方式分析了当地中学生在认知与响应地震灾害方面的一些特点,得出了以下初步结论:年级越高的学生对地震灾害知识的掌握情况越好.地震烈度越高的地区,学生目前对地震灾害知识的认知程度越高,对问卷中震时和震后表现的回答越积极、合理.对地震灾害的认知和响应没有明显的性别差异,民族差异只在灾时自救互救行为方面较为明显.学生的认知程度与其响应行为具有较为显著的正相关性,即认知程度好则响应行为更加积极、合理.媒体和学校教育共同构成了当地学生认知地震灾害及学习基本减灾技能的两大主要途径.在此基础上提出了一些加强对该地区中学生进行针对性减灾教育的建议.     

络合铁法脱除垃圾填埋气中的H_2S

建立了以EDTA和柠檬酸为铁盐络合剂的循环脱硫体系,采用络合铁法对垃圾填埋气中的H2S进行脱硫中试实验,结果表明实验所建立的络合铁脱硫体系运行稳定,脱硫效率高,适合应用于垃圾填埋气中硫化氢脱除.     

一株高效脱硫菌的分离鉴定和脱硫特性研究

从污水净化厂二沉池回流污泥中分离到一株硫杆菌菌株dj-5,该菌株是一种兼性厌氧菌,通过生理生化特性鉴定,并结合16S rDNA序列分析及鉴定,该菌株可以确定为脱氮硫杆菌（Thiobacillus denitrificans）。该菌株的生长曲线表明菌体生长迅速,延滞期约为8 h,然后细菌进入对数生长期,这一阶段持续时间大约20～24 h,稳定期较短,细菌很快进入衰亡期。通过脱硫工艺实验考察了pH值、温度和搅拌速度对脱硫率和菌体生长的影响,结果表明,在进气量180 L/h、pH=6～8、温度为25～35℃和搅拌速度为270 r/min时,该菌株能正常生长,对进气浓度高达2 500 mg/m³的硫化氢脱除率在91%以上。