改性植被混凝土基材力学与植生试验研究

为探明羧甲基纤维素钠(CMC)与麦秸秆纤维对植被混凝土基材力学与植生性能的影响,通过直剪试验、植生试验研究了改性后植被混凝土基材(简称改性基材)的抗剪性能与黑麦草生长性能.结果 表明:①改性基材的剪切强度随CMC掺量的增加呈先增后减的变化趋势,0.5％CMC掺量时基材的剪切强度出现峰值,而随纤维掺量的增加改性基材剪切强...     

Aging of PVDF and PES ultrafiltration membranes by sodium hypochlorite: Effect of solution pH

Sodium hypochlorite (NaClO) is a commonly applied cleaning agent for ultrafiltration membranes in water and wastewater treatment. Long-term exposure to NaClO might change the properties and performance of polymeric membranes, and ultimately shorten membrane lifespan. Active species in NaClO solution vary with solution pH, and the aging effects can change depending on the membrane material. In this study, the aging of polyvinylidene fluoride (PVDF) and polyethersulfone (PES) membranes by NaClO at pH 3–11 was investigated by examining variations in chemical composition, surface charge, surface morphology, mechanical strength, permeability, and retention ability. Polyvinyl pyrrolidone (PVP), which was blended in both membranes, was oxidized and dislodged due to NaClO aging at all investigated pH values, but the oxidation products and dislodgement ratio of PVP varied with solution pH. For the PVDF membrane, NaClO aging at pH 3–11 caused a moderate increase in permeability and decreased retention due to the oxidation and release of PVP. The tensile strength decreased only at pH 11 because of the defluorination of PVDF molecules. For the PES membrane, NaClO aging at all investigated pH resulted in chain scission of PES molecules, which was favored at pH 7 and 9, potentially due to the formation of free radicals. Therefore, a decrease in tensile strength and retention ability, as well as an increase in permeability, occurred in the PES membrane for NaClO aging at pH 3–11. Overall, the results can provide a basis for selecting chemical cleaning conditions for PVDF and PES membranes.     

次氯酸钠处理终冷水中氰化物硫化物的研究

以次氯酸钠为氧化剂,用正交实验研究了次氯酸钠处理终冷水中氰化物和硫化物,得出正交实验中各因素的主次关系及对除氰除硫的影响。研究结果表明,反应体系的pH是影响脱氰脱硫的重要因素。在最佳处理条件,即pH为10．0,反应温度为25℃,投氯量系数为1．4,反应时间为45min．能使氰化物的质量浓度降至0．267mg／L,脱氰率高达99．8％,硫化物的质量浓度降到0．387mg／L,脱硫率达92．0％,达到≤0．5mg／L的国家排放标准。文章还对工业化提出了一些设想。     

Oxidation inhibition of sulfite in dual alkali FGD system

A laboratory-scale well-mixed thermostatic reactor with continuously blasting air was used to investigate the oxidation inhibition of sulfite in dual alkali flue gas desulfurization （FGD） system. The effects of operating parameters such as pH value and catalyst concentration on the oxidation were studied. Sodium thiosulfate was used in the system, and was found that it significantly inhabited the sulfite oxidation. In the absence of catalyst, sodium thiosulfate at 12.67 mmol/L had an inhibition efficiency of approximately 98%. While in the presence of catalyst, sodium thiosulfate at 26.72 mmol/L had an inhibition efficiency less than 85.0%. The oxidation reaction order of sulfite in the sodium thiosulfate was determined to be -1.90 and 4）.55 in the absence and presence of the catalyst, respectively. Apparent activation energy of oxidation inhibition was calculated to be 53.9 kJ/mol. Pilot tests showed that the consumption rate of thiosulfate agreed well with the laboratory-scale experimental results.     

阳离子型微乳液一亚硫酸钠光度法测定α-TNT

以阳离子型微乳液ＣＰＣ／正戊醇／正已烷／水为介质，进行了α－ＴＮＴ－Ｎａ２ＳＯ３分光光度法的研究（ε＝３．０６５×１０４Ｌ·ｍｏｌ－１·ｃｍ－１）与以ＣＰＣ为介质（ε＝２．６４４×１０４Ｌ·ｍｏｌ－１·ｃｍ－１）比较，测定灵敏度明显提高，α－ＴＮＴ在０．０５～２０μｇ／ｍＬ范围内符合比耳定律．相对标准偏差０．１９７％．该法成功地应用于污染土壤中及合成水样中α－ＴＮＴ的测定．     

异烟酸——吡唑啉酮光度法测定水中氰化物方法的探讨

在用异烟酸-吡唑啉酮光度法测定水中氰化物时，用氢氧化钠代替，N，N-二甲基甲酰胺作为溶剂，配制吡唑啉酮作试验，结果表明，改进法代替标准法是可行的，且改进后的显色剂较原显色剂稳定。     

城市污水厂二级生物处理出水氯消毒影响因素研究

进行了城市污水厂二级生物处理出水氯消毒影响因素研究,结果表明:对次氯酸钠,二氧化氯消毒效果影响最大的是pH,其次是有机氮,COD,氨氮的影响相对较小。运用Selleck-Collins公式对数据进行分析。     

碱法草浆黑液厌氧处理中钠的抑制作用

试验了烧碱法草浆黑液中，钠在厌氧过程中的抑制特性。研究表明，钠盐抑制作用强度为：氯化钠＞木素钠＞硫酸钠＞硅酸钠。相对产甲烷率ＰＭ（Ｉ）和钠浓度Ｉ的关系，可用ＰＭ（Ｉ）＝［１＋（Ｉ／Ｋｉ）＾ａ］＾－１拟合，污泥经过驯化，对钠的耐受能力可提高。     

水相催化芳香氯化物脱氯研究

通过把起相转移作用的聚乙二醇（PEG）链，键合到硅胶上，再将聚乙烯吡咯烷酮（PVP）络合双金属Pd-Cu后负载其上，制成一种新型双负载双金属催化剂PVP－PdCl2/SiO2-PEG600,以甲酸钠为氢转移试剂，在水相催水芳香氯化物脱氯，当反应温度80℃左右，n(Pd):n(Cu）=2:1，反应介质pH值11．7左右时，具有较高的催化脱卤活性，催化剂不但易于制备，便于分离，且具有良好的重复使用性能，经重复使用六次，转化率仍在70％以上。     

硫酸铝废渣生产硅酸钠的研究

讨论以硫酸铝废渣经水洗，碱萃取生产硅酸钠的最佳工艺条件，所得硅酸钠产品，符合国家规定．本生产工艺不仅解决了环保问题，还综合利用了资源，具有可观的经济效益．