Studies on the use of power ultrasound in solid–liquid myrobalan extraction process

Focus on eco-friendly processing techniques makes vegetable tanning a viable option in leather processing and establishes the subsequent need for the more efficient methods of extraction in tannin manufacture. Application of ultrasound has been tried in the extraction of tannins from myrobalan nuts in order to improve the extraction efficiency, to perform the extraction under milder process conditions and to reduce the process time. The influence of process parameters such as ultrasonic output power, time and temperature has been studied. Scale-up trials and the use of ultrasound in pulse mode have also been attempted. The results show that a three- to fivefold improvement is possible with ultrasonic output from 20 to 100 W. Extraction efficiency has been calculated from the maximum extractable materials from myrobalan nuts. Extraction efficiency is found to be 90% for ultrasound, 100 W without external heating as compared to 77% for control process at 70 °C for 4 h. Therefore, ultrasound could be employed even dispensing with provision for temperature controls. The use of ultrasound in pulse mode offered 70% extraction efficiency of continuous mode. Scale-up trials indicate that there exists an optimum ultrasonic output power depending on the amount of nuts used, to achieve better extraction efficiency. The effectiveness of ultrasonically extracted tannin solution has also been tested in the tanning process for its applicability. The degree of tanning efficacy has been assessed by shrinkage temperature measurement. The results indicate that ultrasonically extracted tannin solution is suitable for tanning process. Therefore, application of ultrasound in tannin extract manufacture is a viable option with added advantages.     

渣油－水乳化液作为路面抑尘剂的研究

为了有效抑制汽车运输路面的扬尘，选择低浓度渣油－水乳化液作为抑尘剂，通过在实验室大量的试验，掌握了一组渣油乳化的最佳配方及其制备工艺，即渣油３％－６％，乳化剂约０．５％，水９３．５％－９６．５％，制备温度＞７０℃．经过室内和现场大规模试验表明，当路面喷洒量达到２．２ｋｇ／ｍ２时，其有效抑生时间达到１０ｄ以上，并且在一定程度起到养路的作用，长期使用可取得显著的综合经济效益．     

低浓度渣油-水系乳化液的抑尘性能现场试验研究

本文介绍了作者用渣油－水系乳化液做路面抑尘剂在某矿露天坑３种不同类型路面进行的大规模工业性试验。现场测定结果表明：这种路面抑尘剂可以获得比较理想的防尘效果，长期使用该乳化液可取得显著的综合经济效益。     

水稻烤田期间N2O排放及其影响因素

水稻田间实验研究了烤田期间的土壤温度、Eh、含水量和裂缝基本性质,矿质态氮以及与氮有关的酶活性的演变规律,及其对N2O排放的影响.试验表明,在水稻分蘖期间烤田,N2O有一个排放高峰,其最高值可达75.6μg·m-2·h-1.在排放高峰后,即使继续烤田,N2O的排放值也将降低.N2O排放与尿素氮肥的施用量没有明显关系.裂缝的生成,改变了N2O的日排放规律.随着烤田时间的延长,脲酶和羟胺还原酶活性呈波动变化,硝酸还原酶活性递减,亚硝酸还原酶活性极低.硝酸还原酶活性与N2O排放之间没有显著相关性.土壤中的脲酶活性与N2O日排放通量呈显著的线性正相关.在烤田期间,NO-3含量呈增加趋势.土壤中的硝态氮含量与N2O排放通量之间呈显著正线性关系.土壤中的铵态氮含量与N2O排放通量之间呈显著负线性相关.     

Simulating dairy liquid waste management options as a nitrogen source for crops

Large scale dairy operations are common. In many cases the manure is deposited on a paved surface and then removed with a flushing system, after which the solids are separated, the liquid stored in ponds, and eventually the liquid applied on adjacent crop land. Management of liquid manure to maximize the fertilizer value and minimize water quality degradation requires knowledge of the interactive effects of mineralization of organic N (ON) to NH₄⁺, crop uptake of mineral N, and leaching of NO₃⁻ on a temporal basis. The purpose of the research was to use the ENVIRO-GRO model to simulate how the amount of applied N, timing of N application, ON mineralization rates, chemical form of N applied, and irrigation uniformity affected (1) yields of corn (Zea mays) in summer and a forage grass in winter in a Mediterranean climate and (2) the amount of NO₃⁻ leached below the root zone. This management practice is typical for dairies in the San Joaquin Valley of California. The simulations were conducted for a 10-year period. Steady state conditions, whereby an equivalent amount of N applied in the organic form will be mineralized in a given year, are achieved more rapidly for materials with high mineralization rates. Both timing and total quantity of N application are important in affecting crop yield and potential N leaching. Major conclusions from the simulations are as follows. Frequent low applications are preferred to less frequent higher applications. Increasing the amount of N application increased both the crop yield and the amount of NO₃⁻ leached. Increasing irrigation uniformity increased crop yields but had variable effects on the amount of NO₃⁻ leached. A winter forage crop following a summer corn crop effectively reduced the leaching of residual soil N following the corn crop.     

采用钙钛矿型催化剂(La0.8K0.2Cu0.05Mn0.95O3)同时催化去除NOx和碳烟的研究

将钙钛矿型催化剂与碳烟均匀混合后置于固定床连续流动反应体系中,利用程序升温反应技术,在模拟柴油机尾气的情况下对同时催化去除氮氧化物(NOx)和碳烟的反应进行了实验研究.通过改变含Cu原料的用量,得到不同Cu取代量的催化剂La0.8K0.2CuxMn1-xO3,性能评价结果表明,La0.8K0.2Cu0.05Mn0.95O3催化剂的综合性能较好,碳烟的起燃温度及NO向N2的最大转化率分别为280℃和58.0%.采用该催化剂,进一步考察了进气中NO浓度、O2浓度、进气总流量及催化剂与碳烟的接触状况对反应的影响.研究结果表明,进气中NO浓度、O2浓度、气体总流量和催化剂与碳烟之间的接触状况对NO的去除率的影响比较明显,而对碳烟起燃温度的影响较小.O2浓度从5%变为7.5%时,碳烟的起燃温度及最大NO转化率分别从280℃和53.8%变为270℃和96.7%.碳烟与催化剂松散接触时,碳烟的起燃温度及最大NO转化率分别为290℃和48.4%,紧密接触时分别为275℃和70.4%.而进气中NO浓度、气体总流量的变化对碳烟的燃烧基本上没有影响,虽然NO的转化率有明显变化,但生成的N2总量基本不变.     

应用被动扩散管监测分析葫芦岛市环境空气NO2时空分布特征

被动扩散技术以其低成本、操作简单、空间覆盖率较高等优点已在西方国家广泛应用于环境空气质量监测与调查,辽宁省环保局通过欧盟项目引进,本技术在葫芦岛市环境空气质量监测应用有4年时间.依据4年环境空气被动扩散管监测基础数据,分析了解葫芦岛市城区大气中NO2时空分布特征:高浓度值出现在交通区,季节上呈现春季明显低于其它季节.     

入冬水生高等植物的衰亡对河流水质的影响

上海市郊河流水体中有很高的氮、磷和有机负菏，由于受水生高等植物生灭的影响，初春河流中的氮、磷和有机负菏明显高于上一年的初冬，河流中的水生高等植物能大量地吸收水体中的氮、磷，抑制藻类生长，净化水质；但其植株残体在水中的腐解，又会重新释出营养元素，造成对水体的二次污染。在冬季，随着水生高等植物的大量死亡这种污染更加明显，应加强对水生高等植物的利用，尝试建立既能净化水质，又有创造经济效益的生态工程模式，使市郊受污水体得到资源化利用。     

含纤维素废水生物水解的应用研究

提取植物或动物纤维所产生的高浓有机废水，含短小纤维、木质素、纤维素、半纤维素、蜡质、果胶及其分解产物(糖、脂肪酸、醇等)，较难生物处理，属含纤维素废水。试验研究和生产应用表明，生物水解对含纤维素废水中高分子有机物，可予分解并提高度水可生化性：在常温、PH约9．5时，水解池污泥浓度达6．5～16．0g/L，容积负荷达2．9kgCOD／m^3．d，COD去除率为24—36％，VFA提高3．9—5．1倍，BOD／COD提高12～16％。分析认为：中温、酸性，纤维素、木素含量低时，水解效果应更好。     

浅谈“三道防线”对防止污染水域的作用

在简要介绍了上海港散装液体危险装货物储运作业发展的基础上，分析了码头装卸作用中存在的防污染问题，提出了“三道防线”是防止污染的有效措施。