膜的污染和劣化及其防治对策

较为系统地介绍了膜污染和劣化的定义和特点,因膜污染和劣化而造成的膜性能变化,以及如何预防、减少或清除膜污染和劣化的一些通用方法。     

多相光催化降解染料废水的研究进展

对光催化降解染料的机理,影响染料光催化降解速率的因素,提高染料光催化降解效率的途径以及光催化降解染料废水的研究进展进行了综述。     

耐火砖附载TiO2光催化降解糠醛废水

以耐火砖为载体,采用简单工艺制得负载型光催化剂TiO2,并研究了利用TiO2/firebrick光催化剂降解糠醛废水,结果表明,在紫外灯下照射60min,糠醛废水的COD去除率可达56．7％,而通入空气有利于污染物的去除。     

Management of organic matter in the tropics: translating theory into practice

Inputs of organic materials play a central role in the productivity of many tropical farming systems by providing nutrients through decomposition and substrate for synthesis of soil organic matter (SOM). The organic inputs in many tropical farming systems such as crop residues, manures, and natural fallows are currently of low quality and insufficient quantity to maintain soil fertility hence there is need to find alternative or supplementary sources of nutrients. Knowledge gained over the past decade on the role of organic resource quality in influencing soil nutrient availability patterns (Synchrony Principle) and SOM maintenance (SOM Principle) provides a strong scientific basis on which to develop management tools. This scientific information must be linked with farmer knowledge and circumstances to provide a realistic approach to soil fertility and SOM management in the tropics. A decision tree has been developed for testing hypotheses about the resource quality parameters that affect nitrogen release patterns and rates. The decision tree is linked to an Organic Resource Database (ORD) with detailed information on the resource quality of agroforestry trees and leguminous cover crops providing a systematic means of selecting organic resources for soil fertility management. The decision tree has also been translated into a practical field guide for use with farmers in evaluating organic materials. The longer-term effects of organic inputs on SOM might also be addressed through the decision tree and database. It is generally believed that materials good for short-term soil fertility will not build or maintain SOM; if true then it is difficult to imagine practical means of maintaining SOM in the African context where short-term fertility issues will take precedence over longer-term maintenance of SOM. This revised version was published online in June 2006 with corrections to the Cover Date.     

Banding increases effectiveness of fertilizer P for alfalfa production

A field experiment was conducted from 1992 to 1996 on an existing alfalfa (Medicago sativa Leyss) stand located on a P-deficient Black Chernozem (Typic Boroll) soil at Ponoka, Alberta, to compare the effectiveness of broadcasting (spread over the soil surface) versus banding (1.5 cm wide band placed 5 cm deep and 15 cm apart, using a coulter-type disc drill) of annual and one-time applications of P fertilizer on dry matter yield (DMY), P-use efficiency of applied P (PUE), protein yield (PY), recovery of fertilizer P (PR), net returns (NR) and non-renewable energy performance of alfalfa hay. There was a marked increase in DMY and PY from all the P application treatments in all the five years. Banding produced greater increase in DMY and PY than broadcasting, with both the annual (by 954 kg DMY ha^–1 and 205 kg PY ha^–1) and one-time application (by 742 kg DMY ha^–1 and 173 kg PY ha^–1) applications. The PUE (averaged across P rates and years) was greater with banding as compared to broadcasting by 58 kg DMY kg^–1 P ha^–1 for annual applications, and by 47 kg DMY kg^–1 P ha^–1 for one-time applications. In the same order, PR values were 16.0 and 12.1% greater with banding than broadcasting. Despite the higher costs of banding than broadcasting, net returns were significantly higher with banding in nearly all years. The differences between banding and broadcasting were generally greater at lower than at higher P rates. Based on the 5-year means, annual and one-time P applications produced similar increase in DMY, PY, PUE, PR and NR. In contrast, non-renewable energy inputs were higher for banding than broadcasting, but energy use efficiency was similar for both methods of application. In conclusion, method of P placement had the greatest effect on DMY, PY, PUE, PR, NR and energy performance, whereas annual and one-time applications showed similar results. The results suggest that alfalfa forage productivity and profitability can be improved by banding the P fertilizer with a coulter type disc in comparison to the conventional application method of broadcasting.     

液体天然橡胶氧化降解制备工艺的比较

采用了3种新的降解体系硝基苯-过氧化氢、过硫酸钾-丙醛和高碘酸制备液体天然橡胶(LNR),并与传统的降解剂苯肼进行了对比.通过正交实验考察了降解剂用量、温度、时间等对粘均相对分子质量(Mη)的影响,并通过红外光谱对降解后橡胶分子的结构进行了探讨,得到最佳降解体系.结果表明:高碘酸降解所得LNR结构单一稳定,当其用量为干胶质量的0.3％、30℃下反应6h可得到Mη为13 067的LNR,高碘酸是最佳的天然橡胶降解剂.     

煤伴生矿物的泥化对选煤厂设计的影响

分析了煤伴生矿物的泥化特性和泥化对选煤的不利影响,说明选煤厂设计时应重视煤伴生矿物的泥化问题,对煤伴生矿物进行泥化试验,依据试验结果选择选煤工艺流程和煤泥水处理设备。论述了煤伴生矿物泥化试验方法和泥化程度的评定步骤,得出了煤伴生矿物泥化程度的评定标准。分析了泥化程度对选煤厂设计的影响,说明当煤伴生矿物泥化严重时,重介选煤工艺应优先考虑预先脱泥方案,如果不脱泥,则应选择两次浮选、双段脱水回收工艺流程,同时还应注意浓缩沉降面积和煤泥水处理设备的选择。最后通过实例分析了泥化程度对选煤厂生产管理的影响,当煤伴生矿物泥化程度属于高泥化程度(HDW)时,应采用高效絮凝剂、凝聚剂及联合加药系统,同时对选煤厂进行改造,保证煤泥水处理工艺系统完善;当煤伴生矿物泥化程度属于中泥化程度(MDW)或中高泥化程度(MHDW)时,不能忽略煤泥水系统的完善性,厂房布置不能过于紧凑。     

用磷表快速测定磷石膏中水溶磷和非水溶磷

用磷表分析法代替磷钼酸喹啉容量法测定磷石膏中的水溶磷和非水溶磷,分析方法简单,经与传统容量法对照,结果准确、可靠,降低了分析成本,能满足生产控制分析需求。     

高密度饱和有机盐钻井液在羊塔克5井的应用

羊塔克地区下第三系井壁失稳问题一直是油田勘探与开发的技术难点,采用适当密度的钻井液技术是复杂地层钻井成功的关键。通过对该地层不稳定因素及其对钻井液施工技术难点分析研究,对钻井液的配伍进行改进,优选了适合该地区的高密度饱和盐水钻井液体系。该钻井液体系具有良好的流变性、造壁性、润滑性和抑制性。现场应用表明,该钻井液体系对该地区的顺利钻进、井下安全及油气层保护有非常好的效果。     

固定化漆酶对弱酸性蓝RAW脱色降解的研究

采用海藻酸钠为载体、戊二醛为交联剂固定的漆酶对弱酸性蓝RAW进行脱色处理.研究了固定化酶的用量、底物浓度、温度、pH对其降解效果的影响.结果表明:固定化漆酶脱色降解弱酸性蓝RAW的适宜条件为酶用量7.5 U/mL、染料浓度150 mg/L、反应的温度为35℃、pH值为4.5.在上述条件下降解4小时,弱酸性蓝RAW脱色率能达到89％.重复使用8次后,脱色率在70％左右.