鸟粪石法回收制肥工业废水中氨氮的中试研究

制肥工业废水中氨氮浓度高,难以直接进行生化反应,采用鸟粪石沉淀法可有效去除并回收氨氮。利用中试反应器回收某制肥工业废水中的氨氮,采用氯化镁与氧化镁作为联用镁源,通过考察不同进料方式、搅拌速度、停留时间等因素的影响,确定了鸟粪石法回收氨氮的最佳工况:采用间歇进水、固体投加镁源的投料方式,搅拌速度300 r/min,停留时间2 h。最佳条件下,氨氮去除率达到93.5%,磷残余率小于0.3%,生成的鸟粪石纯度可达85.6%,砷和铅的质量分数分别为0.0036和0.0008,符合肥料中重金属限值(GB/T 23349-2009),其他重金属均未检出。因此,回收产品有很好的利用价值。经济分析表明磷源是此方法处理成本较高的主要原因。     

稀土废水中高浓度氨氮处理与回收试验研究

为处理稀土分离排放的高浓度NH4 -N废水,采用模拟废水研究了在不同条件下减压蒸馏回收氯化铵对馏出液中NH4 -N浓度变化影响.发现真空度、不同浓度范围及溶液pH对馏出液中NH4 -N浓度有显著影响,在真空度为0.07MPa,溶液pH为3～4条件下蒸馏,可使馏出液中NH4 -N浓度<15 mg/L.实际废水验证试验表明,废水经气浮除油、氨水中和、适量重金属沉淀剂DTCR去除重金属及活性炭吸附微量重金属及油类物质等预处理后,减压蒸馏可获得较高品质氯化铵产品,经分析达到工业级合格产品,馏出液可作为自来水回用于生产.对废水处理成本和收益进行了估算,发现每处理1 m3废水可获得67.1元的经济收入,实现较高的经济效益和生态环境效益.     

A sulfur removal and disposal process through H2S adsorption and regeneration: Ammonia leaching regeneration

An iron oxide solid sponge H₂S adsorbent works by reacting H₂S and turning ferric oxide into ferric sulfide. The ferric sulfide will be converted back into ferric oxide and elemental sulfur when contacting oxygen or air. This study investigates the leaching of elemental sulfur from the solid sponge using anhydrous liquid ammonia as solvent. The leaching treatment expectedly results in effective regeneration of the adsorbent, which is able to lead to a sulfur removal and recovery process suitable for handling the small and mid-sized sulfur production cases, i.e., those less than 10 ton/day sulfur. The leaching does not significantly impair the physical properties, including the adsorbent pellet strength. The adsorption–regeneration (or leaching) cycle could be repeated at least three times. The cumulative sulfur loading can achieve as high as 50% (w/w), three times greater than that in the one-time use. The wash-off in leaching and the spent adsorbent can be made into slurry that is to be injected into underground formations such as depleted oil wells. It is anticipated that this underground injection is safer and more efficient than acid gas injection.     

鸟粪石沉淀法回收污泥处理构筑物中氮磷的研究进展

污水处理厂氮磷的处理和回收已经成为必然。而污泥处理构筑物中氮磷的释放则进一步要求对其中释放的氮磷进行回收。本文介绍了国内外对鸟粪石形成条件、外加镁源以及各种利用鸟粪石沉淀法进行污泥处理构筑物中氮磷回收的研究现状,并对其在污泥处理构筑物氮磷回收中存在的问题进行了论述。     

Impediments to recovery in New Orleans' Upper and Lower Ninth Ward: one year after Hurricane Katrina

In the aftermath of Hurricane Katrina, a rapid succession of plans put forward a host of recovery options for the Upper and Lower Ninth Ward in New Orleans. Much of the debate focused on catastrophic damage to residential structures and discussions of the capacity of low-income residents to repair their neighbourhoods. This article examines impediments to the current recovery process of the Upper and Lower Ninth Ward, reporting results of an October 2006 survey of 3,211 plots for structural damage, flood damage and post-storm recovery. By examining recovery one year after Hurricane Katrina, and by doing so in the light of flood and structural damage, it is possible to identify impediments to recovery that may disproportionately affect these neighbourhoods. This paper concludes with a discussion of how pre- and post-disaster inequalities have slowed recovery in the Lower Ninth Ward and of the implications this has for post-disaster recovery planning there and elsewhere.     

The impact of disasters on small business disaster planning: a case study

A major flood in 1997 forced the evacuation of Grand Forks, North Dakota and caused damage of USD 1 billion. Despite this recent disaster there is only marginal evidence of an increase in disaster recovery planning by businesses that experienced the flood. This finding is consistent with the results of other business-related disaster research. Statistical tests of survey results from 2003 indicate that there is a significantly higher rate of disaster recovery planning in businesses started since the 1997 flood than in businesses started before the flood and still in business. Such an outcome indicates a need for public policy actions emphasizing the importance of disaster planning. Improved disaster planning is an aid to business recovery and the results demonstrate the need for more widespread efforts to improve disaster recovery planning on the part of smaller businesses, even in areas that have recently experienced disasters.     

大气氟污染治理技术

氟化物是当今重要的大气污染物之一,其毒性超过二氧化硫。文章概要叙述我国近年工业废气的氟排放和治理状况。面对日益严峻的污染形势,提请企业界加以关注和治理。文中着重介绍几种常用的技术装备和工艺流程。     

含油污泥资源化技术研究进展＊

含油污泥资源化技术的研究,应该重视多种热源热解技术开发,包括微波热解技术的研究。文章着重对含油污泥热解技术的研究进行了总结,包括微波热解技术的进展情况。研究得出:热解技术有望在固体废物处置及其资源化、有机质热解作低碳能源等方面发挥越来越重要的作用。开展含油污泥资源化研究,对解决我国国民经济持续发展过程中面临的能源短缺和环境挑战问题具有重要意义。     

废旧电子电器产品资源化利用技术

介绍了废印制电路板处理及资源化技术、废旧冰箱无害化处理及资源回收技术、电视电脑拆解处理设备、废线缆资源回收生产线等四项废旧电子电器产品资源化利用技术的原理、工艺流程、技术特点及应用案例、经济和社会效益。     

碳酸根对磷酸钙沉淀反应回收磷的影响

以模拟的厌氧消化液为处理对象,通过小试实验,考察不同初始磷浓度Cp、Ca／P物质的量比、pH和温度下,碳酸根（CO3 2-）对磷酸钙沉淀反应回收磷的影响;利用扫描电镜（SEM）、x射线衍射仪（XRD）和傅里叶变换红外光谱（FT．IR）对沉淀产物进行表征。结果表明,高浓度的CO3 2-对以磷酸钙沉淀反应去除和回收磷的效率影响较大;Cp相同时,CO3 2-浓度（CCO3^2-）越大,P的去除率越低,低C,（20mg／L）时尤为显著;当CCO3^2-相同时,随着Cp的增大,反应速率加快,P的去除率逐渐升高,但升高幅度越来越小;增大Ca／P比和pH能提高P的去除率,降低CO3 2-对磷酸钙沉淀反应的抑制作用,综合考虑实际效果,应选择Ca／P比为3．33,pH为9．0作为适宜的反应条件;升高温度对降低CO3 2-对磷酸钙沉淀反应的抑制作用贡献不大。在Cp为60ITIg／L,Ca／P比为1．67,pH为9．0,温度为20℃的条件下,当CCO3^2-为0时,得到的沉淀产物主要为羟基磷灰石HAP;当CCO3^2-为30mmol／L时,得到的沉淀产物为磷酸钙和碳酸合磷灰石的混合物。