气相色谱法测定废气中非甲烷总烃的标准气体选择

气相色谱法测定废气中非甲烷总烃,国内外相关标准选用的标准气体各不相同,通过试验考察各标准气体对测定的影响,并比对相关文献信息。结果表明:甲烷和丙烷(浓度以碳计)在填充柱气相色谱仪和毛细管柱气相色谱仪FID检测器上的响应无明显差异,而采用甲烷作为标准气体,分析时间短,工作效率高。     

塞曼原子吸收光谱法测定固定污染源废气中的汞

用PMS 30B型汞采样器采集固定污染源废气,再用塞曼原子吸收汞分析仪测定样品中的汞,高、低浓度汞标准样品测定结果均在标准范围内,相对误差分别为0和4.3%。汞吸收管对高、低浓度含汞废气的穿透效率表明,当废气汞质量浓度达到mg/m3级别时,穿透率仅为1.3%。用该方法测定稳定工况固定污染源废气中的汞,6次测定结果的RSD为5.9%,方法检出限为1.04 ng,当采样体积为20 L时,检出限为0.05μg/m3。实际监测表明,钢铁企业、燃煤电厂、垃圾焚烧厂废气中汞为0.07μg/m3~1 031μg/m3。     

Technological options for the management of biosolids

BACKGROUND, AIM, AND SCOPE: Large quantities of biosolids (sewage sludge), which are produced from municipal wastewater treatment, are ever-increasing because of the commissioning of new treatment plants and continuous upgrades of the existing facilities. A large proportion of biosolids are currently landfilled. With increasing pressure from regulators and the general public, landfilling of biosolids is being phased out in many countries because of potential secondary pollution caused by leachate and the emission of methane, a potent greenhouse gas. Biosolids contain nutrients and energy that can be used beneficially. Significant efforts have been made recently to develop new technologies to manage biosolids and make useful products from them. In this paper, we provide a review of the technologies in biosolids management. MATERIALS AND METHODS: A survey of literature was conducted. RESULTS: At present, the most common beneficial use of biosolids is agricultural land application because of inherent fertilizer values found in biosolids. Expansion of land application, however, may be limited in the future because of more stringent regulatory requirements and public concern about food chain contamination in some countries. Perceived as a green energy source, the combustion of biosolids has received renewed interest. Anaerobic digestion is generally a more effective method than incineration for energy recovery, and digested biosolids are suitable for further beneficial use through land application. Although conventional incineration systems for biosolid management generally consume more energy than they produce because of the high moisture content in the biosolids, it is expected that more combustion systems, either monocombustion or cocombustion, will be built to cope with the increasing quantity of biosolids. DISCUSSION: Under the increasingly popular low-carbon economy policy, biosolids may be recognized as a renewable fuel and be eligible for 'carbon credits'. Because ash can be used to manufacture construction materials, combustion can provide a complete management for biosolids. A number of advanced thermal conversion technologies (e.g., supercritical water oxidation process and pyrolysis) are under development for biosolids management with a goal to generate useful products, such as higher quality fuels and recovery of phosphorus. With an ever-increasing demand for renewable energy, growing bioenergy crops and forests using biosolids as a fertilizer and soil amendment can not only contribute to the low-carbon economy but also maximize the nutrient and carbon value of the biosolids. CONCLUSIONS: Land application of biosolids achieves a complete reuse of its nutrients and organic carbon at a relatively low cost. Therefore, land application should become a preferred management option where there is available land, the quality of biosolids meet regulatory requirements, and it is socially acceptable. Intensive energy cropping and forest production using biosolids can help us meet the ever-increasing demand for renewable energy, which can eliminate the contamination potential for food sources, a common social concern about land application of biosolids. In recent years, increasing numbers of national and local governments have adopted more stringent regulations toward biosolid management. Under such a political climate, biosolids producers will have to develop multireuse strategies for biosolids to avoid being caught because a single route management practice might be under pressure at a short notice. Conventional incineration systems for biosolids management generally consume more energy than they produce and, although by-products may be used in manufacturing, this process cannot be regarded as a beneficial use of biosolids. However, biosolids are likely to become a source of renewable energy and produce 'carbon credits' under the increasingly popular, low-carbon economy policy. RECOMMENDATIONS AND PERSPECTIVES: To manage biosolids in a sustainable manner, there is a need for further research in the following areas: achieving a higher degree of public understanding and acceptance for the beneficial use of biosolids, developing cost-efficient and effective thermal conversions for direct energy recovery from biosolids, advancing technology for phosphorus recovery, and selecting or breeding crops for efficient biofuel production.     

淀粉工业废水处理现状

分析了淀粉工业废水的来源及水质特征。综述了沉淀分离法，化学絮凝法，单纯曝气法，生物处理法，光合细菌法等方法在淀粉废水处理中的应用，介绍了淀粉废水的资源化回收技术。     

ABR反应器处理低浓度废水的研究

对ABR反应器处理低浓度废水的效果及运行特性进行了研究。在中温(35±0.5℃),进水有机负荷为0.5～7.0kgCODCr/(m~3.d),HRT=3～12h,进水CODCr浓度分别为150,350,550和850mg/L时,CODCr去除率分别达50%,80%～87%,86%～92%和90%～95%,反应器出水CODCr浓度在70～90mg/L。研究表明,该反应器处理低浓度废水时,不仅具有良好的处理效果,而且运行稳定。     

生物过滤法处理污泥干化尾气

城市污水处理过程中产生大量污泥,其热干化所产生的尾气主要存在以下特点：气味属刺激性臭气,主体为各种无机、有机化合性气体;热干化过程产生的尾气含有大量的热值,容易对环境造成二次污染。关于污泥干化尾气的处理,目前国内采用的工艺并不很成熟。为了避免污泥干化尾气的二次污染,本着经济适用的原则,本文根据尾气的性质,对生物过滤法处理污泥尾气进行了研究,具体分析了原结构的不合理之处,提出了增湿塔与生物滤塔的改进性建议。     

矿井水微量油处理工艺试验研究

通过矿井水微量油处理工艺试验,研究了混凝剂和吸附剂的最佳投加量、PAC和PAM的最佳配比、吸附接触时间等技术参数与矿井水中微量油的去除率之间的关系。实验结果表明：混凝剂PAC与PAM最佳投加量的质量浓度分别是200mg／L和2mg／L;只投加吸附荆颗粒活性碳,微量油的去除率不高,其最佳投加量质量浓度为40mg／L;吸附接触时间对微量油去除率的影响不大;采取混凝、沉淀、过滤、吸附复合工艺,矿井水中微量油的去除率能达到96％,出水清澈,浊度≤2NTU。     

畜禽养殖污水污染治理现状及发展趋势

畜禽养殖过程中产生的大量污水是目前养殖污染治理的一大难题。针对目前畜禽养殖污水治理过程中存在的管理力度不够、技术可行性差、运行成本过高等问题,提出了今后畜禽养殖污水治理的方向,应以"循环经济"为核心,以污染排放最小化和资源利用最大化为原则,实现经济效益和环境效益的和谐统一。     

日本的废物综合利用现状及展望

综合利用在解决废物问题方面起着重要的作用,促进综合利用不仅可以减少废物的产生量,又可节约地球资源文中介绍了日本废物再利用的现状和面临的问题,阐明了今后为了进一步推进综合利用,不仅要使用再生材料生产产品,而且更有必要去积极地购买这些综合利用产品。      

白腐菌处理造纸黑液工艺研究

研究了白腐菌变异前后对木质素降解效果及脱色率的影响，探索了水解酸化结合白腐菌挂膜工艺处理造纸黑液的可行性。