Re-activation characteristics of preserved aerobic granular sludge

IntroductionThecapacityofawastewatertreatmentplantultimatelydependsupontwofeatures :themetaboliccapabilitiesofthemicroorganismsinthesystemandtheeffectivenessofsolid liquidseparationatthelaststageofthetreatmentprocess(Shwarzenbeck ,2 0 0 4 ) .Granularsludg…     

Comparison of biomass production and biological nitrogen fixation of multi-species pastures (mixed herb leys) with perennial ryegrass-white clover pasture with and without irrigation in Canterbury, New Zealand

Legume-based pastures in Australasia are predominantly perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.). These pastures have disadvantages such as limitations in the production and persistence of white clover and ryegrass in drought prone regions. With the increasing interest in organic agriculture, more complex pasture mixtures are seen as an alternative to the standard ryegrass-white clover (RWC) pasture. Although anecdotal evidence exists to support the benefits of alternative pastures, there is insufficient scientific evidence to support or refute these claims. The present study was conducted to compare three different alternative multi-species (mixed herb leys) (MSP) pastures with the standard RWC pasture with and without irrigation, in terms of biomass and biological nitrogen fixation (BNF) over a period of 1 year under field conditions in Canterbury, New Zealand. Isotopic dilution technique involving field ¹⁵N-microplots were used to measure BNF. Irrigation doubled dry matter yields (DMY) of all pastures compared with those under dryland. There was no significant difference between DMY of all pastures under dryland. However, under irrigation, MSP pastures out-yield RWC pasture in total and legume DMY. Red clover MSP produced significantly lower DMY than the comprehensive or lucerne MSP treatment, probably due to the ability of lucerne in extracting water from deeper soil depth. Seasonal changes in plant composition varied according to the species sown, soil moisture status and temperature. Total and seasonal amounts of N₂ fixed followed the same trend as the DMY and were related to the DMY of legumes. On average, about 26–34 kg N was fixed per tonne of legume DMY, showing a uniformity across all pastures. Overall, based on the present results of 1-year study, the MSP pastures tend to result in higher DMY, BNF and legume growth compared with that of the RWC pasture, provided irrigation is available. With increased BNF, these irrigated MSP pastures may provide high quality feed to grazing animals.     

从ISO14000的实施论清洁生产的市场机制

在回顾市场机制在ISO14000标准成功实施中的作用基础上,对我国清洁生产推动中市场机制的缺乏而影响清洁生产的实施效果进行了反思,提出了基于市场的清洁生产推动机制的设想。     

四川黄龙沟天然水中的深源CO_2与大规模的钙华沉积

在有大规模钙华沉积的四川黄龙沟中,使用化学成分数据以及碳氧稳定同位素组成对其水文地球化学特征进行了分析研究。研究区钙华沉积的地表溪流水质基本上受到两种水混合的制约,即断层泉水和山区的融雪(冰)水。泉水中含有高浓度的经由断层提供的CO2,结果高浓度的溶解CO2使得其溶解的碳酸盐岩比普通的岩溶泉溶解的碳酸盐岩高得多,同时也导致硅酸盐岩的溶解。黄龙沟中上游的泉水相对于方解石接近于平衡。溶解无机碳(DIC)的浓度和它们的δ13C值是大约由c=0.02mol·L1δ13C=-3‰的CO2(aq)与含有δ13C=+3‰的碳酸盐岩在封闭系统条件下反应的结果。估计这些CO2中约有70%来自上地幔。所有泉水的水化学数据均落在高岭石稳定域内,但对Na长石和Ca长石具有侵蚀性。由于这些长石矿物的溶解速率太慢,所以水中的化学成分远离长石稳定域。地表溪流的DIC种类之间达到同位素平衡,在不同观测点发现的δ13CDIC变化主要是由于从水中释放出的CO2的程度不同引起的。水样的δ18O值与其采集点的海拔高度之间存在线性关系;研究区的地表溪流的氧同位素组成受到蒸发的制约。在流经钙华沉积物的地表溪流中白天和夜晚的水化学及pH的日变化表明生物作用促进了碳酸盐的沉积,尽管作用不显著。据估计研究区碳酸钙的日沉积速率是4778kg·km2,即约1mm·a1。     

Cleaner production for continuous digester processes based on hybrid Pareto genetic algorithm

ＩｎｔｒｏｄｕｃｔｉｏｎＷｉｔｈｏｂｓｏｌｅｔｅｔｅｃｈｎｏｌｏｇｙ ,ｅｑｕｉｐｍｅｎｔ,ａｎｄｍａｎａｇｅｍｅｎｔ,Ｃｈｉｎａ′ｓｐｕｌｐａｎｄｐａｐｅｒｉｎｄｕｓｔｒｙｉｓｒｅｃｏｇｎｉｚｅｄａｓｂｅｉｎｇｏｎｅｏｆｔｈｅｍｏｓｔｈｉｇｈｌｙｐｏｌｌｕｔｉｎｇｓｅｃｔｏｒｓ.Ｉｔｓｐｌａｎｔｓｄｉｓｃｈａｒｇｅｄｏｖｅｒ3ｍｉｌｌｉｏｎｔ ａｏｆＣＯＤｉｎ 1 995,ａｃｃｏｕｎｔｉｎｇｆｏｒ 41 .8%ｏｆｔｈｅｏｖｅｒａｌｌｉｎｄｕｓｔｒｙｐｏｌｌｕｔｉｏｎｌｏａｄｏｆＣｈｉｎａ(Ｒｅｎ ,1 998) .Ｉｎｔ…     

低pH对草鱼呼吸活动和耗氧代谢的影响

研究了低pH(6.0—3.6)对草鱼呼吸活动机能及耗氧代谢的影响.结果表明,在pH4.6—3.6条件下,草鱼呼吸和气体代谢活动受干扰的程度随酸度增大而急剧加重.其具体表现为:呼吸率加快,咳嗽反应增加,呼吸深度加大.耗氧率起始升高继而迅速下降,并在极端pH(3.6)下最终引起机体组织缺氧而致死.对于pH5.6,草鱼各类呼吸与代谢指标未受明显影响,基本属于正常.供试草鱼对低pH反应的灵敏程度依次为:咳嗽率>呼吸率>耗氧率>呼吸深度.     

可伸缩接地装置在浮顶罐中的应用

介绍了浮顶罐浮盘与罐壁之间的电气连接--可伸缩接地装置,它易于安装、检测和维护,能快速对地泄放雷电电荷和静电电荷,同时降低雷电流频率下的趋肤效应,尽可能地消除二次电弧,防止油罐密封处产生火花放电引起的火灾.     

探析清洁生产模式在化工企业的应用与效益

介绍了河南神马尼龙化工公司的生产工艺及存在的主要环境问题,指出进行清洁生产的必要性和可行性,并从生产工艺改进、水再生及回用、设备改造、废物回收利用及清洁生产管理等多个方面介绍了河南神马尼龙化工公司实施清洁生产的具体措施,分析了该企业实施清洁生产后产生的效果,实施后达到了充分优化工艺、回收资源、降低系统能耗、减少污染排放、保护环境并取得了良好经济效益和社会效益的三赢目的,对相关企业起到相应的参考作用,从而可以加快清洁生产在化工企业的应用.     

造纸行业环境影响评价中清洁生产评价的实践与思考

造纸行业是资金密集型、技术密集型产业,企业能耗、水耗、资源消耗很大.随着产品产量的增加,行业污染物排放量势必存在增长趋势,造纸行业清洁生产潜力巨大,造纸项目环境影响评价中的清洁生产水平评价变得越来越重要.就造纸行业环境影响评价中清洁生产水平评价的评价指标、评价方法、评价工作中遇到的实际问题以及当前形势对环境影响评价的更高要求以及应对办法等进行了论述.