再生资源回收体系建设巡礼——走进天津乘借滨海新区开发开放的快车道加快天津再生资源回收体系建设

2006年,国务院下发<推进天津滨海新区有关问题的意见>,这是党中央、国务院继深圳经济特区、浦东新区之后,又一带动区域发展的重要战略部署.     

再生资源回收体系建设巡礼——走进石家庄

石家庄市物资回收总公司始建于1956年,是市供销社系统的中型集体企业,下辖17个独立核算单位.现有职工1 200多人,在总公司创办的市场和社区经营的从业人员6 000多人,总资产18 000多万元,拥有经营场地67 hm2(包括合作和租用),经营面积35万m2.     

垃圾渗滤液处理技术

垃圾渗滤液是垃圾填埋过程中产生的高浓度有机废水,是国内外污水处理的一大难题.综述了垃圾渗滤液的水质特性,并总结了近年来在垃圾渗滤液的预处理、主体工艺及深度处理技术上的研究进展,对垃圾渗滤液处理技术提出研究方向.     

进口废塑料清洁程度定量化合格评定方法的探讨

目前国内对进口废塑料清洁程度的合格评定,长期以来一直采取感官检验的定性方法,引起了较多争议.以<进口可用作原料的固体废物环境保护控制标准--废塑料>(GB16487.12)为依据,分析了GB16487.12对进口废塑料清洁程度进行规定的原因,并在此基础上探讨了对进口废塑料清洁程度采取定量化的合格评定原理,提出参照<一般工业固体废物贮存、处置场污染控制标准>(GB18599)和<生活垃圾填埋污染控制标准>(GB16889)对进口废塑料清洁程度制定定量化限量要求,并建议尽快修订现行国家标准<进口可用作原料的固体废物环境保护控制标准--废塑料>.     

台山电厂5号机组烟气脱硝液氨储存区设计

介绍了广东省台山电厂5号机组烟气脱硝工程选用液氨作为反应剂的工艺设计以及针对危险化学品液氨采取的一些具体措施,并对液氨储存区的设计提出了一些看法.     

设置变电站电磁环境影响防护控制区的必要性探讨

通过对几种典型变电站及其进、出线电磁环境实测数据的分析,认为变电站站外不需划定电磁环境影响防护控制区.     

中华全国供销合作总社理事会主任杨传堂赴天津调研

2011年9月5日,中华全国供销合作总社党组书记、理事会主任杨传堂在天津调研。在津期间,天津市委副书记、市长黄兴国会见了杨传堂一行。中华全国供销合作总社党组成员、理事会副主任李春生,天津市人大常委会副主任张元龙,市政府副市长任学锋等陪同调研。     

四种常见锅炉清洗剂及其应用

对四种锅炉常用化学清洗剂的清洗原理、特点、使用范围以及配套助剂进行了详细阐述,并对它们的清洗工艺及应用实例作了介绍.     

加快发展循环经济创建我国北方科学发展示范城市——访大连市发展和改革委员会副主任吕强

发展循环经济,建设资源节约型及环境友好型社会,既合乎世界潮流,也符合我国国情;既是立足当前,着眼长远,更是落实科学发展现.实现可持续发展的重要保证.近日.本刊特约编辑就大连市发展循环经济的有关情况,对大连市发展和改革委员会副主任吕强进行了专访.     

做好组织实施工作 充分发挥政策效果——财政部 商务部有关负责人就家电以旧换新政策答记者问

实施家电以旧换新是继家电下乡、汽车摩托车下乡后,党中央国务院从落实科学发展观、构建社会主义和谐社会的大局出发作出的又一项重大决策.近日,财政部、商务部、发展改革委、工业和信息化部、环境保护部、工商总局、质检总局联合印发了<家电以旧换新实施办法>,受到了社会各方面的极大关注.财政部、商务部有关负责人针对家电以旧换新有关政策问题,接受了记者的专访.     

Determination of the Thermal Efficiency of Pre-boilover Burning of a Slick of Oil on Water

The burning rate of a slick of oil on a water bed is calculated by a simple expression derived from a one-dimensional heat conduction equation. Heat feedback from the flame to the surface is assumed to be a constant fraction of the total energy released by the combustion reaction. The constant fraction (χ) is named the burning efficiency and represents an important tool in assessing the potential of in situ burning as a counter-measure to an oil-spill. The total heat release, as a function of the pool diameter, is obtained from an existing correlation. It is assumed that radiative heat is absorbed close to the fuel surface, that conduction is the dominant mode of heat transfer in the liquid phase and that the fuel boiling temperature remains constant. By matching the characteristic thermal penetration length scale for the fuel/water system and an equivalent single layer system, a combined thermal diffusivity can be calculated and used to obtain an analytical solution for the burning rate. Theoretical expressions were correlated with crude oil and heating oil, for a number of pool diameters and initial fuel layer thickness. Experiments were also conducted with emulsified and weathered crude oil. The simple analytical expression describes well the effects of pool diameter and initial fuel layer thickness permitting a better observation of the effects of weathering, emulsification and net heat feedback to the fuel surface. Experiments showed that only a small fraction of the heat released by the flame is retained by the fuel layer and water bed (of the order of 1%). The effect of weathering on the burning rate decreases with the weathering period and that emulsification results in a linear decrease of the burning rate with water content.     

Selection of adsorbents for treatment of leachate: batch studies of simultaneous adsorption of heavy metals

The simultaneous adsorption of copper (Cu), cadmium (Cd), nickel (Ni), and lead (Pb) ions from spiked deionized water and spiked leachate onto natural materials (peat A and B), by-product or waste materials (carbon-containing ash, paper pellets, pine bark, and semi-coke), and synthetic materials (based on urea-formaldehyde resins, called blue and red adsorbents) or mixtures thereof was investigated. The adsorbents that gave the highest metal removal efficiencies were peat A, a mixture of peat B and carbon-containing ash, and a mixture of peat A and blue. At an initial concentration of 5 mg/l for each metal, the removal of each species of metal ion from spiked water and spiked leachate solutions was very good (>90%) and good (>75%), respectively. When the initial concentration of each metal in the solutions was twenty times higher (100 mg/l), there was a noticeable decrease in the removal efficiency of Cu²⁺, Cd²⁺, and Ni²⁺, but not of Pb²⁺. Langmuir monolayer adsorption capacities, q_m, on peat A were found to be 0.57, 0.37, and 0.36 mmol/g for Pb²⁺, Cd²⁺, and Ni²⁺, respectively. The order of metal adsorption capacity on peat A was the same in the case of competitive multimetal adsorption conditions as it was for single-element adsorption, namely Pb²⁺ > Cd²⁺ ≥ Ni²⁺. The results show that peat alone (an inexpensive adsorbent) is a good adsorbent for heavy metal ions.     

富拉尔基发电总厂200MW机组除尘器改造

对富拉尔基发电总厂5号炉的设计条件进行了分析，针对燃用低硫煤，飞灰比电阻高，场地较小，除尘效率要求高的情况，在电除尘器的设计上采取有效措施，达到了排放要求。     

Calculation of carbon balances for evaluation of the biodegradability of polymers

Establishing carbon balances has been proven to be an applicable and powerful tool in testing biodegradability of polymers. In controlled degradation tests at a 4-L scale with the model polymer poly(-hydroxybutyrate) (PHB), it was shown that the degree of degradation could not be determined with satisfactory accuracy from CO₂ release alone. Instead, the course of degradation was characterized by means of establishing carbon balances for the degradation of PHB withAcidovorax facilis and a mixed culture derived from compost. Different analytical methods for determining the different carbon fractions were adapted to the particular test conditions and compared. Quantitative determination of biomass and residual polymer were the main problems in establishing carbon balances. Amounts of biomass derived from protein measurements depend strongly on assumptions of the protein content of the biomass. Selective oxidation of biomass with hypochlorite was used as alternative, but here problems arose from insoluble metabolic products. Determination of soluble components with the method of chemical oxygen demand (COD) also includes empirical assumptions but seems acceptable if the dissolved carbon fraction is in the range of some 10% total carbon. Results confirm both analytical assays and theoretical approaches, in ending up at values very close to 100%, within an acceptable standard deviation range under test conditions comparable to standard test practice.Paper presented at the Bio/Environmentally Degradable Polymer Society—Third National Meeting, June 6–8, 1994, Boston, Massachusetts.     

袋式除尘器气流分布数值计算研究

采用结构化/非结构化混合网格技术、多孔介质模型及k-ε两方程湍流模型,对某袋式除尘器及进出口管道内的气体流场进行了数值计算.计算结果表明,合理布置导流板后,袋式除尘器两箱体流量偏差为1.8％;除尘器下游滤袋单元处理气量偏大,中游滤袋单元处理气量较小,最大流量与最小流量偏差为22.3％；靠近除尘器进口处灰斗内存在气流回流特性,易造成粉尘的二次附着现象.     

Kinetics of Hydrolytic Degradation of PLA

The chemical recycling of poly(lactic acid) (PLA) to its monomer is crucial to reduce both the consumption of renewable resources for the monomer synthesis and the environmental impact related to its production and disposal. In particular, the production of lactic acid from PLA wastes, rather than from virgin raw materials, it is also possible to achieve considerable primary energy savings. The focus of this work is to analyse deeply the PLA hydrolytic decomposition by means of a kinetic model based on two reactions mechanism. To this end, new experimental data have been gathered in order to investigate a wider temperature range (from 140 to 180 °C) and to extend the water/PLA ratio up to 50 % of PLA by weight. The reported results clearly highlight that more than 95 % of PLA is hydrolyzed to water-soluble lactic acid within 120 min, when it is hydrolyzed within 160–180 °C. Furthermore, the kinetic constant is highly influenced by reaction temperature. The proposed “two reactions” kinetic mechanism complies satisfactorily with the experimental data under analysis.     

Review of the kinetics of alkaline degradation of cellulose in view of its relevance for safety assessment of radioactive waste repositories

The degradation of cellulose (a substantial component of low- and intermediate-level radioactive waste) under alkaline conditions occurs via two main processes: a peeling-off reaction and a basecatalyzed cleavage of glycosidic bonds (hydrolysis). Both processes show pseudo-first-order kinetics. At ambient temperature, the peeling-off process is the dominant degradation mechanism, resulting in the formation of mainly isosaccharinic acid. The degradation depends strongly on the degree of polymerization (DP) and on the number of reducing end groups present in cellulose. Beyond pH 12.5, the OH^- concentration has only a minor effect on the degradation rate. It was estimated that under repository conditions (alkaline environment, pH 13.3-12.5) about 10% of the cellulosic materials (average DP = 1000-2000) will degrade in the first stage (up to 10⁵ years) by the peeling-off reaction and will cause an ingrowth of isosaccharinic acid in the interstitial cement pore water. In the second stage (10⁵-10⁶ years), alkaline hydrolysis will control the further degradation of the cellulose. The potential role of microorganisms in the degradation of cellulose under alkaline conditions could not be evaluated. Proper assessment of the effect of cellulose degradation on the mobilization of radionuclides basically requires knowing the concentration of isosaccharinic acid in the pore water. This concentration, however, depends on several factors such as the stability of ISA under alkaline conditions, sorption of ISA on cement, formation of sparingly soluble ISA-salts, etc. A discussion of all the relevant processes involved, however, is far beyond the scope of the presented overview.     

Study of Aging Characteristics of Ternary Blends of Polyethylenes—II

Six film samples of low-density polypropylene (LDPE)/linear LDPE (LLDPE)/high-density polypropylene (HDPE) with varying ratios of LDPE (20–45 ... wt%) and LLDPE (25–50 wt%) having a fixed amount of HDPE at 30 wt% were prepared by blown film extrusion technique. The samples were aged at four different temperatures, 55°, 70°, 85°, and 100°C, for four different time periods in the interval of between 150 hours and up to 600 hours. The change in the structure of various constituents and the formation of various oxygenated (peroxy and hydroperoxy) and unsaturated groups during thermo-oxidative degradation was discussed by infrared spectroscopy. The visiosity-average molecular weight was found to have decreased slowly in the initial aging hours and temperatures, whereas it decreased by 10% with its previous value tensile strength that is, 100°C when aged for 600 hours. The tensile strength of the sample first increased by 67% at 55°C and 89% at 70°C up to 450 hours, whereas the values increased by 52.5% at 85°C and 33.9% at 100°C when aged for 150 hours and then decreased. The percentage elongation at break increased by 2.7% at 55°C and 10.7% at 70°C for 150 and 300 hours of aging, respectively, whereas the percentage decreased when aged at 85°C and 100°C for up to 600 hours of aging. The values of gel content (percent) increased and initial degradation temperature decreased with aging time and temperature.     

燃煤催化剂的废弃物资源开发

介绍了燃煤催化剂的成份,说明其废弃物资源的丰富性,指出开发过程中应注意的事项.     

废旧冰箱塑料回收再生利用技术研究

目前我国的废旧冰箱已进入了一个报废高峰期,且大量废旧冰箱塑料的处理问题已成为当今地球环境保护的热点问题,而我国又是一个人均资源占有量很低的国家,因此,对废旧冰箱塑料进行回收与再生利用则具有极其重要的意义.介绍了废旧冰箱塑料的物理再生利用、化学再生利用、生物降解、能源回收利用的技术和方法.