环保型多功能水处理剂的合成

以丙烯酸（AA）、2－丙烯酰胺基－2－甲基－丙磺酸（AMPS）、次磷酸钠及过硫酸钠为原料,合成了一种含膦基、羧基和磺酸基的多功能水处理剂。探讨了原料配比、反应温度、反应时间对合成产品阻垢性能的影响,反应温度为100℃、反应时间为4h、单体质量比AA∶AMPS＝3∶1、Na2S2O8∶nAH2PO2∶(AA AMPS)=2.5∶15∶100时,该聚合物阻CaCO3、Ca3(PO4)2及锌盐沉积的综合性能最佳。     

环保型脲醛树脂胶粘剂的合成研究

介绍了聚乙烯醇(PVA)、三聚氰胺在脲醛树脂胶粘剂合成过程中所起的改性作用,研究了反应温度、反应体系pH、甲醛与尿素摩尔比、PVA和三聚氰胺用量对脲醛树脂胶粘剂性能的影响。试验结果表明,在反应温度为80℃、反应体系pH为5．0、甲醛与尿素摩尔比为1．5、PVA和三聚氰胺用量分别为尿素与甲醛溶液总质量的1．0％和5％的条件下,合成的脲醛树脂胶粘剂的剪切强度为2．99MPa,游离甲醛的质量分数由传统工艺生产产品的0．6％～0．8％降低至0．063％,耐沸水时间为108min,且贮存稳定性好,达到了HJBZ-1998国家环境标志产品技术要求。     

以水作异丁基苯合成终止剂

用水代替乙醇或十水碳酸钠作异丁基苯合成反应的终止剂，进行了一系列试验研究。在小试获得成功的基础上，应用于工业生产，结果表明，用于工业生产是安全可靠的，技术上是完全可行的，经济上是合理的。此项技术具有较好的经济、环境和社会效益。     

倒极电解法合成聚合氯化铝絮凝剂

为减少电解制备絮凝剂过程中的极化现象,用特制的自动倒极电源装置合成聚合氯化铝(PAC)絮凝剂。确定了合成的最佳工艺条件：电解槽电压2V;电流密度6A／dm2;倒极周期1s。与不采用倒极装置相比,在最佳条件下合成PAC时,该装置可明显抑制极化现象。处理模拟水样试验表明,该法制备产品的絮凝效果优于一般电解法制备产品及市售产品的絮凝效果。     

绿色有机电合成与可持续发展

综述了有机电合成的发展状况、基本原理及优点,阐述了有机电合成技术在实施“绿色化工”战略过程中的重要作用及主要应用领域,论述了有机电合成与可持续发展的关系。     

阴极电势对微生物电合成系统还原CO2合成有机物性能的影响

采用微生物电合成系统（MES）还原CO₂合成有机物,从微生物菌群、有机物积累量、库伦效率、电化学分析等多个角度研究了阴极电势对MES还原CO₂合成有机物性能的影响。实验结果表明：阴极电势为-0.70 V时,甲酸和乙酸的积累量均最大（分别为1.554 mmol/L和2.754 mmol/L）,系统的总库伦效率最大（为81.42%）;在MES中,醋杆菌（Acetobacterium sp.）、假丝酵母菌（Candida sp. S）、地杆菌（Geobacter sp.）为优势菌种。     

合成塑料的生物降解性及其检测

本文介绍了合成塑料的生物降解性、降解取决因素、微生物所起分解作用的形式、降解机理以及国内外多种常用的和改良的检测其生物降解性的方法,并指出对可生物降解性合成塑料的开发是解决废塑料物品在环境中累积的有效手段。     

自催化法合成聚天冬氨酸

以马来酸酐和乙酸铵为原料,在微波条件下用自催化法合成了聚天冬氨酸（PASP）。通过正交实验确定了最佳合成条件：n（乙酸铵）：n（马来酸酐）=1．2,微波功率为1200W,反应时间为10min。在最佳合成条件下,PASP的收率为91．6％,PASP的黏均相对分子质量约为1．5×10^4。经红外光谱表征和核磁共振氢谱测试结果表明,PASP的各种主要官能团表现明显。当Ca^2＋质量浓度为250mg／L、PASP加入量为3mg／L时,PASP的阻垢率达到95％,表明PASP具有较好的阻垢性能。     

我国合成脂肪酸工业的三废治理及发展前景

文中论述了我国石蜡氧化法合成脂肪酸工业自六十年代以来的发展及其在国民经济中的作用;介绍了国内外合成脂肪酸工业的三废治理情况;展望了合成脂肪酸工业的发展前景。     

间接电合成对甲基苯甲醛减废工艺

采用间接电合成法生产对甲基苯甲醛,不仅产品的产率高,而且由于实现了电解媒质的循环使用,使整个过程无废液排放,既节省了资源,又保证了环境。该法以对二甲苯为原料,其反应过程为：Ｍｎ（Ⅱ）电解氧化生成Ｍｎ（Ⅲ）;Ｍｎ（Ⅲ）氧化对二甲苯生成对甲基苯甲醛。上述反应,前者的电流效率较高,为８５％左右;后者的产品产率较高,约为６９％。     

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.     

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.     

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.     

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。     

Effects of temperature on the release of nutrient elements of solid organic materials under conditions of oversaturation

The effects of temperature on the release of chemical components of six solid organic materials under conditions of oversaturation were investigated in this paper. The six materials were peat moss (PM), weathered coals (WC), charred rice husks (CRH), sawdust (Sd), turfgrass clippings (TC), and chicken manure (CM). Significant differences were observed in the available nitrogen and phosphorus content of the aqueous extracts of organic materials at different temperatures. The available nitrogen content in aqueous extracts of PM and WC at 25 °C was higher than that registered at 15 °C and 35 °C. Available nitrogen content in the aqueous extracts of CRH, Sd, TC, and WC at 35 °C was higher than at 15 °C and 25 °C. The available phosphorus content in the aqueous extracts of organic materials at 35 °C was higher than that available at 15 °C and 25 °C, with the exception of Sd. In addition, the release of available phosphorus in the aqueous solution of organic materials at different temperatures varied constantly for 108 h. The release of potassium (K⁺) and sodium (Na⁺) ions in the aqueous extracts of organic materials was basically steady over time, with the exception of CM. High temperature (35 °C) may significantly hasten the release of K⁺ from organic substrates (except for WC) with low temperatures significantly inhibiting release of K⁺ in Sd and CRH. High temperatures (35 °C) might significantly facilitate the release of Na⁺ in CM and TC. However, no significant differences were manifested in the release of Na⁺ from organic substrates at different temperatures, with the exception of CM and TC. Moreover, no significant differences were observed in the release of calcium, magnesium and iron ions with time, nor were there any significant differences in the contents of iron ions in the aqueous extracts of organic materials at different temperatures. The results indicate that multiple mediums should be pretreated in water for a week before being used for planting. They should be used when all mineral elements of organic materials are steady and ignoring the effect of organic mediums.     

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.     

Effect of depth of landfill on the characteristics of soil-like material of aged waste: a case study of Bhalswa dumpsite,India

Journal of Material Cycles and Waste Management - This study characterizes the municipal solid waste (MSW) accumulated for more than 25 years at Bhalswa dumpsite, Delhi, India. 50...     

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.