RISK IN IRRIGATION WATER SUPPLY AND THE EFFECTS ON FOOD PRODUCTION1

ABSTRACT: This paper examines irrigation water supply deficit and associated risk indicators due to random climate events and potential effects on irrigated food production during the period 1996 to 2025 for seven river basins in the USA, China, and India. An integrated water and food model with global scope is applied for the analysis. The global climate regime during 1961 to 1990 is used to generate 30 climatic scenarios for the time period 1996 to 2025, and these scenarios are applied to the model in order to characterize the randomness of precipitation, runoff, and evapotranspiration, which affects both irrigation water supply and demand. The risk with random climate events is represented by reliability, variability, and vulnerability from different perspectives. Regarding irrigation water supply, Colorado will bear an increasingly unstable situation although the average water supply relative to the demand will maintain at a relatively high level; selected basins in China and India indicate that significantly lower levels of reliability and more deleterious affects from drought can be expected, but under a less variable condition due to assumed water storage increase. From 1996 to 2025, the effects of water deficits on irrigated food production are characterized with a nonlinear phenomenon and food production loss will be more sensitive to irrigation water supply deficit in the future. Future work following this paper needs to consider the impact of global climate change and the water quality of the irrigation return flow and result verification by local studies.     

某卷烟厂卷接机组集中风力与除尘系统的应用

结合贵州某卷烟厂技术改造实践，采用集中工艺风力和除尘技术，对PASSIM和SUPER9卷接机组的工艺风力供给方式和除尘系统进行了改进。对于系统的结构、可靠性、调节性、稳定性进行了分析，改造后集中风力系统较常规风力系统在经济效益和工作环境上具有显著优势，降低了运行成本。     

Recycling of spent nickel-cadmium batteries based on bioleaching process

Only 1-2 percent of discarded dry batteries are recovered in China. It is necessary to find an economic and environmentally friendly process to recycle dry batteries in this developing country. Bioleaching is one of the few techniques applicable for the recovery of the toxic metals from hazardous spent batteries. Its principle is the microbial production of sulphuric acid and simultaneous leaching of metals. In this study, a system consisting of a bioreactor, settling tank and leaching reactor was developed to leach metals from nickel-cadmium batteries. Indigenous thiobacilli, proliferated by using nutritive elements in sewage sludge and elemental sulphur as substrates, was employed in the bioreactor to produce sulphuric acid. The overflow from the bioreactor was conducted into the settling tank. The supernatant in the settling tank was conducted into the leaching reactor, which contained the anode and cathodic electrodes obtained from nickel-cadmium batteries. The results showed that this system was valid to leach metals from nickel-cadmium batteries, and that the sludge drained from the bottom of the settling tank could satisfy the requirements of environmental protection agencies regarding agricultural use.     

Dust Storm as an Environmental Problem in North China

Dust storms in north China, which are associated with land deterioration from increasing human pressures, have intensified over the past decades. Although synoptic meteorological conditions and sedimental environments dictate the occurrence of dust storms, their increase in frequency in north China due to human activities can be expected. Sand stabilization and control projects may be compromised by the pursuit of short-term economic returns and lack of systematic and integrated understanding of land degradation. Two actions are recommended as positive responses to escalating dust storms in north China. A policy of long-term ecologically sustainable development strategies is needed as well as a scientific research initiative combining biophysical and socioeconomic aspects.     

城市污泥毒性有机物对草履虫综合毒性研究

本文以好氧发酵处理前、后城市污泥中毒性有机物提取液为实验液，以草履虫为实验动物进行了综合毒性研究。结果表明：好氧发酵前的实验液对草履虫的半致死浓度为５５９３ｍｇ／ｌ，发酵后的实验液对草履虫的半致死浓度为５６０５３ｍｇ／ｌ。     

二氧化钛光催化降解处理染料废水

研究了TiO2的添加量，粒径大小，作用时间对3种染料废水脱色率的影响及TiO2薄膜对染料废水的处理效果。对于汽巴克染绿和直接大红染料溶液，适宜的TiO2添加量均为5g/L，紫外灯照射60min，其脱色率大于85％。对于阳离子红染料溶液，适宜的TiO2添加量为3g/L，其脱色率为83．5％。粒径小的TiO2作用效果优于粒径大的效果。在室温和适宜的TiO2添加量的条件下，随照射时间的延长，太阳光的光催化降解效果渐渐接近于紫外光的光催化降解效果。将TiO2薄膜固定在陶瓷睛上，有利于TiO2的重复使用。     

高炉煤气全干式布袋除尘净化技术

通过对国内外大中型高炉煤气除尘系统的分析比较，对高炉煤气除尘系统几个重大技术问题提出自己的见解，并指出新建、改建、扩建大中型高炉为避免重复投资，应不建湿式除尘系统备用，而向建干式布袋除尘方向发展。     

天山巴音布鲁克麝鼠资源及其保护利用

本文报道了１９７９年天山巴半布鲁克区外贸站从博斯腾湖引进麝鼠１０００余只，放养 于巴音布鲁克大小尤勒都期治泽地后１０年内的资源消长，本报记者麝鼠不同栖息地的环境状况，外形特征，引进麝射种的利弊及其保护利用等问题。     

液膜分离技术及其在环境工程中的应用

液膜分离技术是用于混合物分离的一种新型有效的技术,液膜是由两个不混溶相形成乳液,然后将乳液在第三相(连续相)中分散而成。本文介绍了液膜的组成、类型与结构、液膜分离的机理和操作工艺流程。井以若干实例说明了该项新技术在环境工程水处理中的广泛应用。     

新类型混流风机除尘器的研制与应用

摒弃国内外惯用除尘器加风机的技术路线,研制具有除尘通风双重功能的混流风机除尘器,它可干湿两用除尘,除尘效率达98％以上。整机结构简单,体积小,易于维护,能耗低,造价低,是工矿企业一种新型的除尘器。