Preparation and Application of Polymers as Inhibitors for Calcium Carbonate and Calcium Phosphate Scales

The scale inhibitor was prepared based on itaconic acid (IA), styrene p-sulfonic sodium (SSS), maleic anhydride (MA), and acrylamide (AM) as monomers, and ammonium persulfate as an initiator by the free-radical polymerization. The structure of the polymer was characterized by FT-IR and UV-Vis spectroscopy. Using the static experiment method, the scale inhibition efficiency to CaCO₃, the effects of some factors (concentration of polymer, time, concentration of Ca²⁺, pH value, concentration of HCO₃ ^?, and temperature) were investigated. Using the malachite green photometric method, the scale inhibition efficiency to Ca₃(PO₄)₂ and the effects of some factors (concentration of polymer, time, Ca²⁺, pH, temperature, and the concentration of PO₄ ^3?) were also investigated. The experimental results showed that the polymer had an excellent efficiency of scale inhibition and a resistance rate of calcium carbonate scale up to 96.67%, a resistance rate of calcium phosphate scale up to 92.5%, and could be used in the system of high-temperature and high-hardness water. The polymer had good dispersing ability with respect to iron.     

Volatility of Simulated High-Level Nuclear Waste Glass by Thermogravimetric Analysis

The volatilities of simulated, high-level nuclear waste glasses have been measured using thermogravimetric analysis (TGA). These volatilities were measured in the region of the glass transition temperature ( T _g) of the waste glasses, which is between 450° and 500°C. These data were obtained because the Waste Acceptance Preliminary Specifications require that no foreign materials be released into the canistered waste form upon heating of the canister to this glass transition temperature. In fact, all of the waste glass samples studied actually exhibited a net weight gain upon heating. This weight gain was shown to be due to oxygen uptake through oxidation of FeO. Powdered glass samples did show a small weight loss which was smaller in magnitude than the weight gain and was associated with water desorption. No true volatility was detected to the level of sensitivity (0.01 wt%) of the TGA instrument. This converts to a sensitivity of 330 μ g/m² of glass surface and a corresponding minimum value of 41 mg of volatiles for each Defense Waste Processing Facility conistered waste form. TGA experiments carried out at higher temperatures (800°C) revealed that organic concentrations in the waste glasses are less than 0.01 wt%. Thus, these results demonstrate that the Defense Waste Processing Facility will be able to comply with the Waste Acceptance Preliminary Specifications on the exclusion of foreign materials from the canistered waste forms, after exposure to T _g.     

ZX型阻垢剂在食盐电解液蒸发过程中的阻垢性能

Rapid fouling tests were used to investigate the scale-preventing property of ZX type scale in hibitors inevaporation of salt electrolyte. ZX type scale inhibitors were tested at high temperature under the boiling conditions.The results indicate that ZX type scale inhibitors have remarkable scale preventing performance during evaporation of salt electrolyte even at the temperature up to 150~C. Among them, ZX IR type scale inhibitor is the best with the rate of scale-preventing reaching to 88.9%. In addition, the scale preventing mechanism of ZX type scale inhibitors was analyzed and its application prospect in the field of continuous commercial fouling preventing discussed.     

甲硫醇钠生产中废水的处理方法

本文提供了一种废水处理方法，用所述及的氯氧化处理方法可彻底净化有机中间体化合物甲硫酸钠生产的恶臭，有毒废水，解决了废水污染问题，同时能回收部分硫氢化钠和芒硝，降低了生产成本。     

Immobilization of Sodium in Perovskite

Perovskite, a candidate phase for the immobilization of Nabearing nuclear waste, shows excellent Na leach resistance in deionized water, when hot-pressed to 97% theoretical density at 1200°C. Surface reactions in two brines appeared to be minimal.     

Na+浓度对化学增强钠铝硅酸盐玻璃性能的影响

熔盐中少量的Na⁺并不会对玻璃的离子交换效果产生明显影响,但当熔盐中Na⁺浓度不断增大时,化学增强钠铝硅酸盐玻璃的性能开始受到影响。本文采用一步法离子交换工艺研究了熔盐中Na⁺浓度对不同厚度化学增强钠铝硅酸盐玻璃表面压应力、应力层深度和弯曲强度等性能的影响。研究表明:熔盐中Na⁺浓度不断增大时,化学增强钠铝硅酸盐玻璃的表面压应力、弯曲强度下降;弯曲强度下降最多可达175 MPa,此时玻璃的表面压应力下降了57.4 MPa;熔盐中Na⁺浓度变化未对化学增强钠铝硅酸盐玻璃的应力层深度和可见光透过率产生明显影响。     

泡花碱在味精废水处理中的应用及其废渣的利用

叙述了泡花碱处理味精废水的作用原理及对处理废水后的废渣的利用。实验结果表明 :经泡花碱处理后的味精废水COD降低至 1× 10 4 mg/L以下 ,pH =7.0～ 8.0。     

甲壳胺质量检测的方法

研究提出了甲壳胺的游离氨基含量测定、粘度测定、水分测定、灰分测定及分子量测定的方法。     

由甲壳素生产壳聚糖的废液制备双乙酸钠

用甲壳素生产壳聚糖产生的高浓度强碱废液制备防腐剂—双乙酸钠。对废液脱色、浓缩、投入乙酸的量、反应时间、反应温度、干燥温度与时间等制备条件进行了研究,确定了最佳工艺条件。所得产品中含40.45%乙酸和58.45%乙酸钠,水含量小于2%,质量符合FAO/WHO标准。     

Sodium Diffusion in the Nuclear Waste Glass GP 98/12

The diffusion of²² Na was measured in the nuclear waste borosilicate glass GP 98/12 in the temperature range of 350° to 450°C. The boundary condition of a thin initial tracer layer and serial sectioning were employed to measure the diffusion profiles. The activation enthalpy was found to be 1.08 eV. A parallel experiment with the base glass VG 98/12 not containing added (chemically simulated, inactive) waste showed that Na diffusion does not vary significantly when adding the waste.     

利用废硅胶生产五水偏硅酸钠的研究

概述了五水偏硅酸钠的市场现状,介绍了以废硅胶为原料生产五水偏硅酸钠的实验方法。通过实验,得出了优化实验条件为:模数采用0.5~0.8,波美度在35~50°,加热废硅胶及浓缩结晶的温度为90~100℃,时间为持续沸腾5min以上,采用自然降温法,时间在10h左右。最终制得良好的晶体,其中氧化钠含量为28.5%,氧化硅含量27.3%,产品质量达到国内同类产品的一级品标准。     

从脱硫废液中提取硫氰酸钠的工艺进展

介绍了改良ADA法脱硫的反应机理和反应历程,阐述了脱硫废液中回收NaSCN在资源环境方面的意义。并且对溶析结晶法,分步结晶法,膜分离法,凝胶色谱法,阴离子交换树脂法和萃取法提取NaSCN的主要工艺技术进行了分析比较。     

Application of Mixture Models to Solubility Calculations,Using Sodium Oxalate as an Example

Abstract

The solubility of solids in nuclear waste impacts many separation processes including evaporator set-points, pressure drops in ion-exchange columns, as well as the washing and leaching of sludge. Scheffe and Cox type empirical mixture models have long been used to model crystal stability in nuclear waste glass melters, and this methodology has now started being employed to model solubility in aqueous nuclear wastes. The large amount of theory and data available for aqueous systems allows for the opportunity to evaluate mixture models for solubility calculations. In the present paper, it is shown that Scheffe type mixture models should be employed when the pure component is the standard state of interest whereas the Cox type mixture models should be employed when infinite dilution is the standard state. An example application is used to demonstrate that mixture models can be used to predict solubility, even across a phase boundary, when combined with the standard thermodynamic equations for the solubility product. The example employed is Na₂C₂O₄ solubility in aqueous NaNO₃ solutions, which can be thought of as a simplified high-level nuclear waste supernatant.     

地聚物材料固化含砷废渣抗硫酸盐侵蚀性能研究

用磷渣-粉煤灰基地聚物材料对含砷废渣进行固化处理,研究含砷固化体的抗硫酸钠侵蚀性能,考察不同硫酸钠浓度、干湿循环次数等因素对固化体质量、抗压强度、砷毒性浸出特性的影响,并采用XRD和SEN分析硫酸钠侵蚀前后固化体的物相组成及形貌变化.结果表明:当干湿循环为1～4次时,材料强度可提高11％～21％;当干湿循环为5～8次时,固化体结构在干湿周期性作用下被破坏,逐步出现微孔、大孔,固化体的结构缺陷致使固化体抗压强度降低(5％～20％),砷浸出率增大,但其不超过0.3％,可见含砷地聚物材料固化体有较强的抗硫酸盐侵蚀性.     

用水解好氧生物工艺处理碱渣废水

本文分析了废水处理中的水解好氧工艺机理,根据炼厂碱渣废水的水解厌氧预处理实验和应用,讨论了本方案的可行性,为碱渣废水的治理寻求合理的途径。     

化学法ADA脱硫废液中提取硫氰酸钠的实验研究

介绍了从ADA脱硫废液中提取硫氰酸钠的化学处理方法,处理过程包括:活性炭脱色,酸化分解硫代硫酸钠,低温分离硫酸钠,用氢氧化钙去除残留的硫酸钠等。实验条件及步骤:1 L脱硫废液中加入30 g活性炭,脱色温度为70℃~80℃并搅拌1 h;滤液中加入质量分数为98%硫酸17 m L至p H=3~4,分解温度为70℃~80℃并搅拌1 h;将滤液蒸发到体积约300 m L后,冷冻到0℃,分离出水合硫酸钠,滤液中需加入3 g氢氧化钙搅拌,过滤;将滤液蒸发结晶,离心分离,干燥得到硫氰酸钠固体,其纯度为96.3%。     

Sodium zirconium phosphate-based glass-ceramics as potential wasteforms for the immobilization of nuclear wastes

A comprehensive study on the development of sodium zirconium phosphate (NZP)-based glass-ceramic composites as potential wasteforms for the immobilization of nuclear wastes is reported. Two complementary waste treatment routes, the ex situ and in situ crystallisation of NZP with a sodium aluminoborosilicate glass, were investigated with various processing conditions including sintering temperature, cooling rate and NZP to glass ratios. While the ex situ route with mixing of pre-made NZP and glass is a robust and reliable means of producing the glass-ceramic composites, the in situ crystallisation of NZP from an amorphous NZP precursor is a more realistic processing route. The formation of ZrO₂ as a minor phase was observed especially for high NZP to glass ratios due to the solubility difference between Zr and P oxides in glass. The addition of extra phosphate can overcome this and yield glass-ceramic composites with appropriate NZP stoichiometry. Overall, the NZP glass-ceramic system is versatile offering multiple processing options for nuclear waste management.     

Volatilization of 137Cs and 106Ru from Borosilicate Glass Containing Actual High-Level Waste

Volatility of ¹³⁷ Cs and ¹⁰⁶Ru from borosilicate glass containing actual high-level waste was measured in an almost closed stainless-steel canister. The temperature dependence of the volatility of ¹³⁷Cs was close to that obtained in our previous study using ¹³⁴Cs. The volatility of ¹⁰⁶Ru was about one-fifth that of ¹³⁷Cs at 600° and 800°C. The air contamination by ¹³⁷Cs and ¹⁰⁶Ru in the canister at 400°C was estimated at 1.8 × 10² and 2 × 10 Bq/cm³, respectively, when it was assumed that the glass contained a realistic amount of ¹³⁷Cs and ¹⁰⁶Ru expected in commercial waste glass. These results are useful for predicting safety in a storage facility under operation.     

Potential Applications of Enzymes in Waste Treatment

The implementation of increasingly stringent standards for the discharge of wastes into the environment has necessitated the need for the development of alternative waste treatment processes. A review of research directed toward developing enzymatic treatment systems for solid, liquid and hazardous wastes is presented. A large number of enzymes from a variety of different plants and microorganisms have been reported to play an important role in an array of waste treatment applications. Enzymes can act on specific recalcitrant pollutants to remove them by precipitation or transformation to other products. They also can change the characteristics of a given waste to render it more amenable to treatment or aid in converting waste material to value-added products. Before the full potential of enzymes may be realized, it is recommended that a number of issues be addressed in future research endeavors including the identification and characterization of reaction by-products, the disposal of reaction products and reduction of the cost of enzymatic treatment. © 1997 SCI.     

Formation of Technetium Salts in Hanford Low‐Activity Waste Glass

The distribution and physical form of technetium in a Hanford low‐activity waste (LAW) glass was examined with scanning electron microscopy (SEM) and X‐ray diffraction (XRD). A simulated Hanford LAW glass was spiked with varying amounts of potassium pertechnetate and melted at 1000°C. The glass was melted in a sealed quartz ampoule with the air pumped out, so that volatile material could leave the glass but would not be lost from the system. Previous studies have shown that technetium remains in the glass up to about 2000 ppm, but rises to the top of the melt as a separate salt phase above this concentration. Examination by SEM shows that crystals of technetium compounds appear to grow out of the hot glass, which implies that the hot glass was supersaturated in technetium salts. Some of the technetium compound crystals had apparently melted, but other crystals had obviously not melted and must have formed after the glass had partially cooled. The technetium compounds in the salt layer are KTcO₄ and NaTcO₄, according to SEM and XRD. No TcO₂ was found in the salt phase, even though Tc(IV) has been previously reported in the glass.