聚硅酸硫酸铝絮凝剂的研制和性能研究

聚硅酸硫酸铝是一种新型无机阳离子型高效絮凝剂，本文就其研制及应用进行了探索。实验成功地研制了不同Al／Si的产品，并进行了絮凝比较实验。结果表明，Al／Si值是影响其作用效果的关键，其他影响因素还有：pH值、絮凝刺投加量、絮凝温度以及原水性质等，并在经济核算的基础上确定了最佳絮凝条件。该产品可应用于任何可以利用高聚物析出氢氧化铝凝胶系统的场合。     

电化学法处理聚驱采油废水的研究

采用电化学法处理油田开发三次采油过程中产生的聚驱采油废水,考察了pH值、反应时间、电流强度对污染物降解效果的影响.结果表明,pH=3.25时,COD和HPAM去除率最高,分别达到83.03％和98.66％;电流强度为0.8A时,COD及HPAM去除率最高,为85.24％和99.63％;pH=3.25、电流强度为0.8A时,COD及HPAM去除率随时间延长而增大,反应30 min后去除率基本不变.研究了处理过程中电流效率的变化,发现反应前10 min内电流效率最高,达23.63％;并通过投加与电化学溶出的新生态铁等量的铁盐絮凝剂(FeSO4)分析了电化学中电絮凝作用的贡献,酸性条件下电化学过程对COD去除率为83.79％,同等条件下,FeSO4混凝的COD去除率为70.31％,电化学作用过程中氧化、气浮及电场作用对COD的去除率贡献最高为13.48％,因此,电化学法处理聚驱采油废水的主要作用机理为电絮凝作用.研究表明,电化学法能有效降解聚驱采油废水.     

淀粉黄原酸酯基高吸水树脂吸附重金属离子研究

为了进一步探讨淀粉黄原酸酯基高吸水树脂对水中重金属离子吸附作用的机理及其影响因素,考察了离子总量和pH值对吸附的影响,并用扫描电镜和透射电镜等方法对其进行了表征.结果表明:该树脂对重金属离子的吸附是通过表面吸附、网络结构内部的束缚作用和官能团的络合作用方式实现的;该树脂以过硫酸钾为氧化剂,与马铃薯淀粉黄原酸酯形成氧化还原引发体系,使马铃薯淀粉黄原酸酯和部分水解的丙烯酰胺在较低的温度下接枝聚合,一般在35～45℃即可聚合.此外,淀粉黄原酸酯基高吸水树脂对重金属离子的吸附作用较强,可以应用于去除污水中的重金属离子.     

Effect of adjuvants on rainfastness and herbicidal activity of glyphosate deposits on trembling aspen foliage

Abstract

Radiolabelled end‐use mixtures of glyphosate with and without a cationic surfactant (Ethomeen® T/25) and an organosilicone surfactant (Silwet® L‐77) were applied onto trembling aspen (Populus tremuloids Michx.) leaves at the rate of 1.0 kg of AE (acid equivalent) in 35 L/ha area of foliage. A 5‐mm rainfall with an intensity of 10 mm/h was applied at intervals of 0.5, 8, 24, 36, 48, 72, and 96 h after treatment. Glyphosate washoff was determined by liquid scintillation counting of radioactivity in the rain‐washing. At 36 h post‐treatment, both the adjuvants significantly reduced glyphosate washoff (Ethomeen by 69.6% and Silwet by 59.7%) from foliage, compared to the washoff (82.6%) when Vision alone was applied without the adjuvants. Results on the rate of plant growth indicated that with a rain‐free period of 8 h or more, the growth of most seedlings was stunted within 1 or 2 d. Percentage of foliar browning 20 d after treatment with rain‐free period of 8 to 48 h ranged from 8 to 80% for Vision alone, 75 to 100% for Vision with Ethomeen, and 85 to 100% for Vision with Silwet, respectively. Physical properties of the end‐use mixtures were measured with and without the two adjuvants to examine droplet spreading and drying rates in relation glyphosate rainfastness. The Silwet adjuvant lowered the surface tension of the end‐use mixture, but Ethomeen did not. Droplets containing Silwet were spread more than those containing Ethomeen. However, the greater area of contact caused by Silwet did not contribute to a significant increase in the translocation rate of glyphosate into untreated parts of the seedlings, and showed no relationship with rainfastness of glyphosate deposits on trembling aspen.     

Reactions of model compounds of phenol resin in sub- and supercritical water under an argon atmosphere

Model compounds of phenol resin were reacted in sub- and supercritical water to clarify the mechanism of the decomposition reaction of plastics in water. Cleavage reaction of methylene bonds was confirmed in the reactions of model compounds of phenol resin such as bis(hydroxyphenyl)methanes in sub- and supercritical water under an Ar atmosphere, although the methylene bond was stable in thermal reactions. It was also confirmed that sub- and supercritical water played important roles not only as a stable solvent thermally, but also as a chemical reagent. Received: July 19, 2000 / Accepted: September 14, 2000     

生物酶自动解堵聚合物钻井液的试验研究

为了选择对常用提粘剂形成的聚合物钻井液具有自动解堵效果的生物酶,通过粘度衰减试验和渗透率恢复试验,并辅以显微镜观测,探究了12种生物酶对9种常用提粘剂形成的聚合物钻井液的降粘效果和解堵效果。结果表明:纤维素酶和胍尔胶酶对聚合物钻井液的降粘效果十分明显;胍尔胶酶对胍尔胶溶液和雷硼溶液的自动解堵效果较好;但生物酶能降解聚合物却不一定能实现相应钻井液的自动解堵。     

Preparation and evaluation of bis(diallyl alkyl tertiary ammonium salt) polymer as a promising adsorbent for phosphorus removal

Problems associated with water eutrophication due to high phosphorus concentrations and related environmentally safe solutions have attracted wide attention. A novel bis(diallyl alkyl tertiary ammonium salt) polymer, particularly poly(N~1,N~1,N~6,N~6-tetraallylhexane-1,6-diammonium dichloride)(PTAHDADC), was synthesized and characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance, scanning electron microscopy, mercury intrusion method, and thermogravimetric analysis. The adsorption characteristics in phosphorus were evaluated in dilute solution, and the recycling properties of PTAHDADC were investigated. Results showed that PTAHDADC possessed macropores with a size distribution ranging from 30 to 130 μm concentrating at 63 μm in diameter and had 46.52% of porosity, excellent thermal stability below 530 K, and insolubility. PTAHDADC could effectively remove phosphorus at p H = 7–11 and had a removal efficiency exceeding 98.4% at pH = 10–11. The adsorption equilibrium data of PTAHDADC for phosphorus accorded well with the Langmuir and pseudo-second-order kinetic models. Maximum adsorption capacity was 52.82 mg/g at 293 K. PTAHDADC adsorbed phosphorus rapidly and reached equilibrium within 90 min. Calculated activation energy Eawas 15.18 k J/mol. PTAHDADC presented an excellent recyclability with only 8.23% loss of removal efficiency after five adsorption–desorption cycles. The morphology and structure of PTAHDADC slightly changed as evidenced by the pre-and post-adsorption of phosphorus, but the process was accompanied by the partial deprotonation of the(–CH_2)_3-NH~+ group of PTAHDADC. The adsorption was a spontaneous exothermic process driven by entropy through physisorption, electrostatic attraction, and ion exchange. Survey results showed that PTAHDADC was a highly efficient and fast-adsorbing phosphorus-removal material prospective in treating wastewater.     

Spray atomization characteristics as a function of pesticide formulations and atomizer design

Abstract

The use of formulation adjuvants to increase the drop size of pesticide sprays has followed a practice which has evolved through many years of experimentation and development. The earliest materials used were simply designed to make the spray mix viscous on the premise that a mayonnaise‐like fluid would produce larger drops and hence increase the deposit efficiency. These viscomer materials, emulsions and water soluble thickeners such as starch and agars, as well as more complex cellulose materials, produced thick non‐Newtonian fluids which were difficult to mix, pump and spray, and provided questionable results. First, the larger drops reduced target coverage from a given volume of spray; and second, field tests with these definitely showed that a large volume of small drops were still being produced even with the thickest of formulations.

The next step in adjuvant evolution was the introduction of polyvinyl, polyacrylamide and polyamide elastomer materials. These polymers are also non‐Newtonian, but due to their peculiar molecular bonding, they have the capability of forming long string‐like streams which when atomized can retract into a spray of large drops. Pure forms of these polymers are blended by commercial producers to enable compatibility with pesticide chemicals. We have conducted a series of laboratory and wind tunnel tests; first, to try and establish some physical parameters identifying their characteristics and second, to determine how these adjuvants affect atomization and the production of small drift‐prone drops (i.e., those smaller than 120 μm in diameter).

Our results with the laboratory studies of physical properties and of the wind tunnel drop size tests have been inconclusive. The elastomer materials have relatively low viscosity (1.5 to 6 mPa.s) and reduced surface tension (50 to 60 mN/m) but our stream‐flow extension tests were non‐productive. The drop size studies comparing water sprays with polymer‐water mixtures gave us a mixed picture. Generally drop size was increased for all of the fan (deflector and milled orifice) and cone type atomizers. But an increase was also indicated of the volume of spray in drops less than 120 μm showing that the polymer did not fully control the production of these small drops under all of the testing procedures we studied.

It is difficult to evaluate the capability of these additives for controlling or reducing production of the drift‐prone small drops. While the pure solutions of the water soluble polymers would appear to be capable of this desirable effect, it is also evident that in order to make these formulations compatible with pesticide spray solutions, several other solvents, emulsifiers and surface active chemicals are added to the formulation, thus affecting the atomization characteristics and hence their drift‐control capability.     

新型高聚物煤自燃阻化剂的试验研究

煤堆自然发火是一个严重的经济和安全问题,是重大灾害之一.目前有许多采用阻化剂防止煤炭自燃的技术,但普遍存在阻化效果不稳定、寿命短等不足.本文选用合适的高聚物分子作为阻化剂,并以水玻璃、CaO、表面活性剂等为添加剂.进行双氧水氧化升温试验、程序升温氧化试验和阻化性试验,结果表明,这种新型阻化剂阻化效果良好,阻化率达90%以上.高聚物分子通过物理吸附、机械结合、化学吸附等作用使煤粒相互粘结,最后能在煤堆表面形成一定厚度和一定强度的固化层,覆盖在煤表面,阻缓氧气进入煤体,提高了对煤炭的阻化效果.这种阻化剂无毒无害、使用方便,具有良好的应用前景.     

新型天然有机高分子阳离子改性絮凝剂的制备研究

为研发绿色絮凝剂,改善水资源短缺现状,以天然有机高分子玉米芯准纳米粉(QCCP,直径<0.147 mm)为母体,用三乙胺与环氧氯丙烷共聚产物为阳离子单体(M)进行改性.采用H2O2-FeSO4作引发剂,制得一种新型天然有机高分子阳离子改性絮凝剂DXSL-Ⅰ,确定了优化的反应条件.将2.0 g QCCP与含有0.7 g NaOH的8 mL水混合,40 ℃条件下碱化60 min.然后,加入8 mL醚化单体和体系总质量0.01%引发剂以及0.1% NaCl作为抑制剂,55 ℃条件下醚化3.5 h.实验表明,用该絮凝剂絮凝处理高岭土悬浊液时,不到5 min中层透光率就能达到95%以上.其絮凝性能达到传统絮凝剂聚丙烯酰胺的技术指标.此外,运用红外谱图化学结构分析和扫描电镜介观形貌分析辅助说明了改性反应的成功.