活性艳蓝KN-R染料废水的电解氧化及其毒性削减

以Ti／RuO-IrO2为阳极、不锈钢板为阴极,采用电解法处理活性艳蓝KN—R染料废水（简称染料废水）。研究了电解过程中主要因素对染料废水色度去除率的影响,并对处理后废水的生物毒性和可生物降解特性进行了评估。结果表明：在pH为8、NaCl溶液浓度为0．050mol／L、电流密度为10．42mA／cm2、极板距离为3cm的条件下,电解15min染料废水色度去除率达100％;电解120min后,水样的发光细菌相对发光度提高至60．88％,活性污泥耗氧速率常数较原水提高了103％,说明染料废水的毒性得到了有效削减,可生化性得到明显改善。     

蒙脱石基絮凝剂处理染料废水

采用先酸活化蒙脱石、再加碱聚合的方法制备了蒙脱石基絮凝剂（PMT）,用于去除染料废水的TOC和色度。实验结果表明：PMT处理2BLN分散蓝、KNR活性艳兰、X-3B活性艳红模拟染料废水的最佳加入量分别为0．30。0．30,0．25g／L。在此最佳条件卜,2BLN分散蓝、KNR活性艳兰和X-3B活性艳红模拟染料废水的TOC去除率分别为77．0％,89．2％,39．5％,脱色率分别为41．2％,43．1％,57．4％。PMT对KNR活性艳兰和2BLN分散蓝实际染料废水的TOC去除率高于聚合氯化铝（PAC）和聚合硫酸铁（PFS）,分别为91．6％和88．4％。但PMT对X-3B活性艳红实际染料废水的TOC去除率及对3种实际废水的脱色率均低于PAC和PFS。     

黑曲霉对水溶性染料的吸附研究

用黑曲霉对6种水溶性染料废水进行吸附脱色,当染料质量浓度为100mg／L时,6种染料废水的脱色率均达到88％以上。对培养液的光谱分析表明,染料废水的脱色是由吸附引起的。考察了氮碳源种类、碳源浓度、培养基pH和染料浓度对染料废水吸附脱色效果的影响。结果表明,（NH4）2SO4和葡萄糖是较好的氮碳源,葡萄糖质量浓度为2．5～10．0g／L时,随着其质量浓度的增加,脱色率增加;当染料质量浓度为50～200mg／L时,随着其质量浓度的增加,脱色率下降;pH对脱色率有一定的影响,但pH为4～9时,脱色率均较高。对吸附了染料的菌体进行解吸,发现甲醇是较好的解吸溶剂。     

膨胀石墨对直接染料废水吸附脱色研究

以鳞片石墨、乙酸酐、浓硫酸、重铬酸钾为原料制备了膨胀体积为350mL／g的膨胀石墨。以膨胀石墨为吸附剂，对直接大红4B、甲基橙染料废水进行了吸附脱色研究，探讨了影响吸附的因素。实验结果表明：直接大红4B（质量浓度300mg／L）、甲基橙（质量浓度200mg／L）的吸附平衡时间分别为6h和5h；在相同质量浓度（200mg／L）下，pH对两种染料废水的脱色率影响不大，膨胀石墨对直接大红4B废水的脱色率在93％以上，对甲基橙废水的脱色率最高只有70．4％；直接大红4B废水的脱色率随温度的升高而增加，甲基橙废水的脱色率随温度的升高而减小，但吸附量受温度的影响不大，两种染料的吸附符合Langumuir吸附等温式。     

生物质吸附剂处理活性艳红X-3B废水

采用城市污水处理厂二沉池的剩余活性污泥为原料，以浓度为3mol／L的ZnCl2溶液浸泡污泥，采用水蒸气为活化气和保护气，在600℃下活化污泥3h，制备出性能良好的生物质吸附剂，其碘吸附值为388．95mg／g，比表面积为447．79m^2／g，平均孔径为4．39nm，孔体积为0．31cm^3／g，微孔体积为0．09cm^3/g。实验结果表明，用该生物质吸附剂处理活性艳红X-3B废水，在废水（10mL）中活性艳红X-3B质量浓度为300mg／L、生物质吸附剂加入量为0．20g、吸附时间为30min的条件下，废水脱色率可达99．7％。活性艳红X-3B在生物质吸附剂上的吸附行为遵循Lagergren二级动力学规律，同时也可用一级吸附动力学方程描述。     

新生二氧化锰吸附法去除水中直接大红染料

研究了影响新生MnO2对直接大红4B染料废水脱附脱色的有关因素，结果表明，pH是影响脱色效果的关键因素，吸附脱色存在佳化pH范围，其上限随染料浓度的提高和MnO2投加量的增加而增大。投加0．3g/L的MnO2可使染料废水的脱色率达到98．2％，升高温度可提高脱色率。     

酰基化反应废水的综合利用

以含AlCl3的酰基化反应工业废水为原料,采用聚芳醚砜酮中空纤维超滤膜为反应介质制备聚合氯化铝（PAC）。通过正交实验考察了碱浓度、碱化度、碱类型和加碱速率对PAC絮凝性能的影响。经优化后的试制参数用于PAC的放大实验,并将试制产品应用于染料废水的处理,考察了PAC对一定浓度的染料废水（达旦黄、活性红、甲基橙和食品黄）的脱色效果。实验结果表明,在NaOH溶液浓度0．5mol／L、渗透压0．2MPa、碱化度2．0时制备的PAC对4种染料的脱色率均大于96％。     

活性艳蓝X-BR降解菌的筛选

从某印染厂废水排放出口的污泥中分离到一株活性艳蓝X-BR染料高效降解菌LPY68-14,经生理生化鉴定,该菌为埃希氏菌(Escherichia sp.).研究了影响菌株LPY68-14降解效果的因素,实验结果表明:在缺氧、质量分数为0.2%葡萄糖为外加碳源、温度37℃、接种量4 mL、pH 7的最佳条件下,质量浓度为30 mg/L的活性艳蓝X-BR经菌株LPY68-14处理24 h后的降解率可达80%;当活性艳蓝X-BR质量浓度为100～400 mg/L时,该菌处理48 h后的降解率可稳定在70%左右.     

用Co3O4催化剂光催化氧化活性染料

以沉淀一热解法制备了纳米级Co3O4催化剂,并用X射线衍射仪、红外光谱仪对Co3O4催化剂进行了表征。以300W高压汞灯为光源,研究了Co3O4催化剂对不同活性染料的光催化氧化活性。实验结果表明：在活性染料质量浓度为20mg／L、250mL染料溶液中Co3O4催化剂加入量为150mg、反应2h的条件下,Co3O4催化剂对B—GFF黑、B—RN蓝、K—NR艳蓝3种活性染料溶液的脱色率分别为95％,87％,77％;适当加入酸或碱有利于提高处理效率,反应后染料溶液的pH为7．12～8．37,染料溶液初始pH为10．00时的脱色率最高为100％;Co3O4催化剂具有一定的再利用价值。     

微波紫外协同降解染料活性艳红X-3B研究

将微波激发的无极紫外灯应用于染料废水的处理研究,考察了反应过程中染料废水脱色率、TOC去除率、溶液pH以及反应前后染料废水高效液相色谱图的变化情况。染料活性艳红X-3B经无极紫外光处理110min后,脱色率达96％,TOC去除率达66％,降解效果明显好于单独使用微波或普通紫外灯的降解效果总和,溶液pH先降低后缓慢升高。     

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.     

Determination of the Burning Characteristics of a Slick of Oil on Water

The burning rate of a slick of oil on a water bed is characterized by three distinct processes, ignition, flame spread and burning rate. Although all three processes are important, ignition and burning rate are critical. The former, because it defines the potential to burn and the latter because of the inherent possibility of boilover. Burning rate 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. 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%). Ignition has been studied to provide a tool that will serve to assess a fuels ease to ignite under conditions that are representative of oil spills. Two different techniques are used, piloted ignition when the fuel is exposed to a radiant heat flux and flash point as measured by the ASTM D56 Tag Closed Cup Test. Two different crude oils were used for these experiments, ANS and Cook Inlet. Crude oils were tested in their natural state and at different levels of weathering, showing that piloted ignition and flash point are strong functions of weathering level.     

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.     

Model of technological alternatives of production of sodium chromate (VI) with the use of chromic wastes

This article presents a mathematical model which describes the sodium chromate (VI) production process with the use of chromic waste as a substitution of natural raw materials. This model is a function of selected process parameters common for all of the examined alternatives and based on equations of material balance. Optimization of the elaborated technological alternatives of the production process with use of recycling of chromic waste has been evaluated by determining the extreme value of the quality indicator WJ. This indicator defines the quantity of waste created in the process. Optimization results enabled the selection of the optimal technological solution from all of the alternatives possible for use in industrial practice. Negative values of the indicator prove that there is the possibility of introducing to the process a larger quantity of waste than the one obtained in the process and transported to the storage heaps.     

鼓泡式反应器高径比对氨法烟气脱碳性能的影响

以N2和CO2混合气模拟燃烧烟气,研究了鼓泡反应器的高径比以及反应条件对氨法烟气脱碳性能的影响。实验结果表明:在相同高径比的条件下,CO2吸收率随氨水质量分数的增加、反应温度的升高而逐渐增大,随进气CO2体积分数和模拟烟气流量的增加而逐渐减小;CO2吸收率随高径比的增加而增大,在高径比为3.98、氨水质量分数为28%、进气CO2体积分数为10%、模拟烟气流量为1.0L/min、反应温度为40℃的条件下,CO2吸收率最高可达100%。     

化学品生物降解性的评价与预测

介绍了有机化学物质生物降解性的测定方法及其预测方法研究概况，并讨论了生物降解性评价的发展前景。     

Structure-biodegradation relationships of polymeric materials. 1. Effect of degree of oxidation on biodegradability of carbohydrate polymers

The biodegradability of oxidized starch and inulin has been studied in relation to the degree of periodate oxidation to dialdehyde derivatives, by measuring oxygen consumption and mineralization to carbon dioxide. A higher degree of oxidation of dialdehyde starch and dialdchyde inulin results in a lower rate at which the polymers are biodegraded. It is demonstrated that the biodegradation rate of dialdehyde inulin derivatives decreases more than that of equivalent starch derivatives. The differences in biodegradation behavior between dialdehyde starch and dialdehyde inulin, resulting from comparable modifications, are discussed in terms of conformational structure.     

Mechanism of Microbial Degradation of Slow-Release Fertilizers

Methyleneureas are condensation products of urea and formaldehyde of different molecular mass and solubility; they are used in large amounts both as resins, binders, and insulating materials for industrial applications, as well as a slow-release nitrogen fertilizer for greens, lawns, or in bioremediation processes. In the present study, the microbial breakdown of these products was investigated. The nitrogen was released as ammonia and urea, and the formaldehyde released immediately oxidized via formiate to carbon dioxide. The enzymatic mechanism of metabolization of methyleneureas was studied in microorganisms isolated from soil, which were able to use these compounds as the sole source of nitrogen for growth. A strain of the Gram-negative bacterium Ralstonia paucula (formerly Alcaligenes sp. CDC group IVc-2) completely degraded methylenediurea and dimethylenetriurea to urea, ammonia, formaldehyde, and carbon dioxide. The enzyme initiating this degradation (methylenediurease) was purified and turned out to be different from the previously described enzyme from Ochrobactrum anthropi with regard to its regulation of expression and physicobiochemical properties. Fungal degradation of methyleneureas may occur via the formation of organic acids, thus leading to a nonenzymatic degradation of methyleneureas, which are unstable under acidic conditions.     

Effect of Degree of Substitution of Octenyl Succinate Starch on Enzymatic Degradation

Octenyl succinate starch of degree of substitution (ds) 0.03, 0.07, and 0.11 was synthesized in an aqueous medium. These compounds were then tested for the susceptibility to enzymatic degradation. The multiple-enzyme regime of -amylase, amyloglucosidase, and pullulanase was chosen for the evaluation. This combination of enzymes had been proven to degrade 99.5% of unmodified starch to glucose and hence was chosen for this study. It was found that even small amounts of subsituent caused a considerable decrease in the extent of degradation. The net extent of degradation decreased with increasing ds. Surprisingly, the amount of glucose from all three substituted substrates was quite similar, suggesting the effect small amounts of subtituent had on the enzymatic activity.