河北丰宁坝上高原寒区抗灾补墒灌溉基本途径

我国是世界上高原众多的国家,高原面上土地资源丰富,而长期干旱缺水困扰高原农业的发展,当前生产水平低。“八五”期间采用半移动式喷灌获得成功,粮食单产可从现在的每公顷７５０ｋｇ,提高到５２５０ｋｇ,大多数作物品种一年便可收回投资成本。巨大的增产潜力,对于我国粮食生产供应态势趋紧具有特殊意义。     

生物膜填料塔净化低浓度有机废气的可行性验证实验

用生物膜填料塔对实际工业低浓度甲苯废气的净化处理进行可行性验证。结果表明；用生物膜填料塔对实际工业低浓度甲苯废气净化是可行的，净化效果良好。     

多层螺旋雾幕技术的喷雾模拟及降尘试验研究

为了解决掘进工作面传统喷雾除尘无法有效抑制粉尘扩散的问题,提出了一种将气动喷嘴呈螺旋状布置的多层螺旋雾幕除尘方法。采用k-ω湍流模型与K-H液滴破碎模型,通过Comsol多物理场耦合数值模拟,得出了多层螺旋雾幕速度场分布和粒子轨迹的变化规律,结合模拟结果搭建试验平台,并将多层螺旋雾幕与传统喷雾的除尘效果进行对比分析。以2层雾幕为例的模拟结果显示,喷雾2 s时就会形成明显的2层螺旋状雾幕,10 s后旋转水雾充满整个模拟区域,并且雾滴粒径较传统喷雾更小。试验表明多层螺旋雾幕的除尘效果明显强于自然降尘与传统喷雾,3 min后可将浓度470 mg/m3左右的粉尘降到4 mg/m3以下。     

一种SCR脱硝装置喷氨混合系统的结构优化设计

氮氧化合物是主要的大气污染物之一,已经成为我国大气污染控制的重点。SCR(selective catalytic reduction)烟气脱硝技术因其脱硝效率高、运行稳定而成为目前应用最为广泛的烟气脱硝技术。当前SCR烟气脱硝工程存在的主要问题之一是氨气的逃逸率过高,喷氨混合系统的混合强度和均匀度是影响氨气逃逸率的重要因素。针对该问题采用计算流体动力学的方法优化设计了一种SCR脱硝装置喷氨混合系统,采用该种喷氨混合系统可以有效提高氨气与烟气在催化剂表面的混合均匀度,使氨气与烟气中的氮氧化物在催化剂表面充分反应,有效降低氨气逃逸率,同时降低SCR脱硝工程成本。     

湿式电除尘器给排水技术的研究与应用

湿式电除尘器是作为燃煤电厂大气污染治理的终端精处理设备的首选,但湿式电除尘器存在耗水量巨大、排出的灰水存在二次污染、内部件腐蚀严重等问题,严重影响了湿式电除尘器在国内燃煤电厂上的大型化应用。为此,对湿式电除尘器的喷淋给水、水质、灰水循环利用、废水排放等进行了研究分析并结合实际工程应用经验加以阐述,提出了科学合理的给水和排水方式,实现了湿式电除尘器在燃煤电厂工艺系统上的零水耗,有效解决了内部件腐蚀问题。     

A chemical residue survey in relation to the 1930 spruce budworm spray program in New Brunswick (Canada)

Abstract

This paper describes the results from a pesticide residue survey conducted in relation to the 1980 spraying of insecticides in New Brunswick (Canada) to preserve the coniferous forest from an on‐going spruce buciworm infestation. A total of 465 water and air samples were collected from 12 sites throughout the Province.

In water, fenitrothion was usually detected at about the same time that spraying occurred in the immediate area of the sites. The maximum that was ever detected was 2 0.0 ppb and persistence was usually United to a few days except in a small pond where fenitrothion was detected for a total of 18 consecutive days. Aminofenitrothion was also detected at a maximum of 8.0 ppb.

Fenitrothion was only detected occasionally in air samples the maximum being 1.2 ng/dm³. However, aminofenitrothion was present in several air samples at c. maximum of 12.0 ng/dm ³.     

Efficiency of deposition of pesticide droplets on flat cards and spheres

Abstract

The mass flux of a cloud of droplets heading towards a collector can be decomposed into its horizontal and vertical components. While only the vertical mass flux contributes to droplet deposition on a flat card by the mechanism of sedimentation, both flux components contribute to deposition on a sphere by both mechanisms of inertial impaction and sedimentation. Calculated collection efficiencies decrease as wind speed increases for cards but as wind speed increases for spheres, a minimum collection efficiency is reached at a certain wind speed. The average collection efficiencies, as measured in the field trial portion of this study, are highly linearly correlated with wind speed for cards. For spheres, however, no correlation was found between the average collection efficiency and wind speed.     

生物填料塔处理餐厅污水的研究

分别以自行开发的组合型填料和焦炭作生物载体构成的生物填料等塔对餐厅污水处理进行了试验研究,试验考察了污水入塔COD值对塔中DO的影响,观察到的结果表明：长期在高入塔COD下运行对生物膜系统的持久、稳定不利;水力停留时间取3h－4h,COD的容积去除负荷为4kg/m^3.d时,出水既可达标,又可保持较高的处理能力;鼓风曝气时,气水比取8－12可使出水达标,而功耗较低;在相同的微生物系统和操作条件下,布水布气性好的组合填料处理效果高于布水气性差的焦炭。     

一种新型除尘器在梅山铁矿选厂的应用

介绍了喷雾双向旋流除尘器的原理及在矿山选厂除尘中的应用。     

循环喷淋洗涤技术在生产应用中存在的问题及解决方法

中国石油宁夏石化公司采用循环喷淋洗涤技术回收尿素造粒塔粉尘,在该回收系统的运行过程中,存在排气中尿素粉尘含量偏高的情况,从设备管理和工艺优化等方面查找原因,制定应对措施并逐一进行实施,从而降低造粒塔排气中尿素粉尘的含量,减少空气污染,达到了污染减排的目的。