小氮肥厂排水中主要污染物的确定及其流失量控制探讨

清江化肥厂采用等标污染负荷的评价方法,找出厂外排水中主要污染物。氨氮是对外环境影响的主要污染物,占总污染负荷的72.9％,年排放量为115.79吨,占厂外排废水中污染物总量的31.36％。合理的减少氨的流失,是控制氨氮污染的主要途径。通过对氨氮废水源的控制与治理,每年少排含氨废水65万吨,年回收合成氨170吨,消除了产品的流失,并减少软水的消耗,仅后两项就可为企业增加16.7万元/年的经济效益。     

含腈废水处理过程中污染物的转化规律

对某石化企业含腈废水的处理工艺进行了评估,从污染物的来源、组成、处理效果等方面研究了污染物的转化规律,揭示了现有工艺在含腈废水处理过程中的问题。实验结果表明:该企业污水处理场的废水来源较多,丙烯腈生产废水经四效蒸发系统处理后的出水是其污染物的主要来源,含有相对较多的含氮共轭体系;与其他废水混合后,经氨化作用,有机腈转变为有机胺和铵盐;A/O工段矿化度较高,COD的去除率高达73.0%,但有机胺含量仍较高;在缺氧池—生物流化池—硝化池工段,COD进一步被去除,胺类物质浓度大幅降低,但总氮脱除效果并不理想。     

沸腾炉大气污染物的生成与排放特征分析

以20台沸腾炉(功率小于等于60 MW)的燃料特性分析数据和大气污染物的排放实测数据为基础,利用统计分析方法,研究了燃烧过程中排放的颗粒物(PM)、SO_2和NO_x初始排放浓度的影响因素,分析了沸腾炉PM、SO_2和NO_x排放现状,探讨了我国中小型沸腾炉PM、SO_2和NO_x排放管理控制的潜力和可行性.实验结果表明:在锅炉运行负荷大于等于80%的条件下,中小型沸腾炉PM的初始排放浓度基本上不受锅炉出力、过量空气系数和燃煤灰分含量的影响;燃煤的硫含量越高,SO_2初始排放浓度越高;过量空气系数越大,燃煤挥发分越低,NO_x初始排放浓度越高.     

废水污染物排放总量控制指标的确定及控制对策

着重论述了株洲化工集团有限责任公司废水污染物排放总量控制指标的确定方法,并简述了排放总量控制对策。     

电厂煤粉炉燃煤中硫的转化规律研究

利用50组燃煤电厂现场测试数据,研究了在煤粉炉燃烧条件下,不同煤种、不同地区烟煤中硫转化为烟气中SO2的份额。研究认为,目前我国电厂煤粉炉燃煤中硫转化为烟气中SO2的份额平均值取0．85是适宜的。     

活性污泥焚烧过程中镍的迁移分布特性

采用管式炉对污水厂活性污泥焚烧过程中Ni的迁移分布特性进行研究。实验结果表明：当污泥掺烧量（污泥质量与煤和污泥总质量的比）为25%时,Ni的挥发率（飞灰与气体中Ni质量的总和与污泥中Ni质量的比）几乎为零,且污泥与煤混合试样的综合燃烧效果最好;当污泥焚烧加入硫化物时,各种硫化物对Ni的残留率（炉渣中Ni的质量与污泥中Ni质量的比）提高能力大小顺序为Na₂S>S>Na₂SO₃>Na₂SO₄;当污泥焚烧加入氯化物时,促使Ni向烟气中迁移,且加入无机氯更易使Ni向烟气中迁移。     

石化综合污水生化处理中有机污染物的分析

运用GC-MS、紫外光谱及三维荧光光谱扫描技术考察了石化污水处理厂“水解酸化—厌氧处理—好氧处理”工艺的各单元出水中有机污染物的变化情况。总进水中检出84种主要有机污染物,主要含有烃类27种,酚类5种,醛、酯、醇和酮类化合物共24种,胺类4种,腈、有机酸及其他杂环化合物14种,另有10种物质未定性;该工艺的COD累积去除率达87.66%, 64种有机污染物被完全去除,17种有机污染物去除率可达90%以上,接触氧化池出水中主要含杂环化合物和少量醛、醇、酯类化合物。     

电子废弃物中持久性有机污染物分析检测方法的研究进展

针对目前电子废弃物中持久性有机污染物(POPs)尚未形成有效快速分析检测方法的问题,介绍了溶剂萃取、固相萃取、微波萃取和超临界流体萃取等POPs前处理技术的研究进展,总结了POPs的分析方法,如:气相色谱、液相色谱、气相色谱-质谱法、高分辨率气相色谱-高分辨质谱法等化学分析方法,以及生物传感器测定法、表面胞质团共振检测法、酶联免疫检测法等生物分析方法。分析了各方法的优劣,并提出了展望。     

一种用尾矿吸附废水中磷污染物的方法

该发明公开了一种用尾矿吸附废水中磷污染物的方法。其步骤为：（1）将尾矿中粒径大于1cm的矿石和一些掺杂的植物根系拣出,摊开自然晾干后磨细至200目;（2）将磨细的尾矿放在马弗炉中高温焙烧,焙烧温度控制在300～500℃,焙烧时间控制在1．5h以上;（3）将焙烧后的尾矿按15～22g／L加入到磷质量浓度为0．5—50mg／L的废水中,调节废水的pH为5～10,充分混合反应后,废水中磷去除率达90％以上。     

危险废物焚烧厂烟气净化工艺设计与探讨

参考国内外已有的危险废物焚烧工程相关设计和研究资料,针对国内具有代表性的危险废物成分,采用设计计算得到危险废物焚烧烟气的污染物初始浓度,分析成熟的烟气净化工艺,对适合中国危险废物特点的危险废物焚烧厂烟气净化工艺进行了设计和探讨,为危险废物焚烧厂建设单位及设计单位等提供参考。     

垃圾焚烧中抑制二恶英二次生成的方法探讨

根据生活垃圾焚烧技术中二恶英的生成机理,余热锅炉的烟气在低温区急冷可以避免二恶英在低温区的再次合成,但目前在余热锅炉烟气低温区急冷是不可行的。提出一种从垃圾焚烧系统设计上进行烟气的急冷,从而抑制二恶英低温区二次生成的新方法。     

日本生活垃圾焚烧灰渣的资源化利用

日本生活垃圾的焚烧率高达80％,对焚烧灰渣的处理也比较先进,其资源化利用方式主要有在熔融设施进行熔融处理后制成熔融灰渣、作为水泥原料及路基材料等.介绍了日本生活垃圾焚烧灰渣的产生及资源化利用情况,以期对我国处理焚烧灰渣有所借鉴.     

Simulation of co-incineration of sewage sludge with municipal solid waste in a grate furnace incinerator

Incineration is one of the most important methods in the resource recovery disposal of sewage sludge. The combustion characteristics of sewage sludge and an increasing number of municipal solid waste (MSW) incineration plants provide the possibility of co-incineration of sludge with MSW. Computational fluid dynamics (CFD) analysis was used to verify the feasibility of co-incineration of sludge with MSW, and predict the effect of co-incineration. In this study, wet sludge and semi-dried sludge were separately blended with MSW as mixed fuels, which were at a co-incineration ratios of 5 wt.% (wet basis, the same below), 10 wt.%, 15 wt.%, 20 wt.% and 25 wt.%. The result indicates that co-incineration of 10 wt.% wet sludge with MSW can ensure the furnace temperature, the residence time and other vital items in allowable level, while 20 wt.% of semi-dried sludge can reach the same standards. With lower moisture content and higher low heating value (LHV), semi-dried sludge can be more appropriate in co-incineration with MSW in a grate furnace incinerator.     

Recycling of air pollution control residues from municipal solid waste incineration into lightweight aggregates

This work focuses on the assessment of technological properties and on the leaching behavior of lightweight aggregates (LWA) produced by incorporating different quantities of air pollution control (APC) residues from municipal solid waste (MSW) incineration. Currently this hazardous waste has been mostly landfilled after stabilization/solidification. The LWA were produced by pelletizing natural clay, APC residues as-received from incineration plant, or after a washing treatment, a small amount of oil and water. The pellets were fired in a laboratory chamber furnace over calcium carbonate. The main technological properties of the LWA were evaluated, mainly concerning morphology, bulk and particle densities, compressive strength, bloating index, water adsorption and porosity. Given that APC residues do not own expansive (bloating) properties, the incorporation into LWA is only possible in moderate quantities, such as 3% as received or 5% after pre-washing treatment.The leaching behavior of heavy metals from sintered LWA using water or acid solutions was investigated, and despite the low acid neutralization capacity of the synthetic aggregates, the released quantities were low over a wide pH range.In conclusion, after a washing pre-treatment and if the percentage of incorporation is low, these residues may be incorporated into LWA. However, the recycling of APC residues from MSW incineration into LWA does not revealed any technical advantage.     

Investigation of hydrogen generation from municipal solid waste incineration fly ash

Hydrogen generation from municipal solid waste incineration fly ash was investigated to understand the influences of contacting method, kinds of contact solution, liquid to solid ratio, and particle size distribution of materials. Redox properties of materials and hydrogen generation were also studied. The largest quantity of gas generated in contact with water was 29.1 ml/g-ash, most of which was hydrogen. Fluidized bed fly ash generated more gas than stoker fly ash. In order to calculate the hydrogen generation potential (the maximum quantity of gas generated in contact with water), a novel system using a Y-shaped test tube and NaOH was utilized. This method gives values which are related to the quantity of generated gas in contact with water. A relationship between the aluminum content and hydrogen generation potential was observed, especially for fluidized bed fly ash. The reducing potential of fluidized bed fly ash was higher than that of stoker fly ash. Only fluidized bed fly ash showed a positive correlation between aluminum content and reducing potential, and between reducing potential and hydrogen generation potential. These results suggest that fluidized bed fly ash contains more Al⁰ than stoker fly ash. Received: September 11, 1998 / Accepted: March 19, 1999     

Behavior of TiO2 nanoparticles during incineration of solid paint waste: A lab-scale test

In order to assess the potential impacts posed by products containing engineered nanoparticles, it is essential to generate more data about the release of these particles from products’ life cycle. Although first studies were performed to investigate the release of nanoparticles from use phase, very few data are available on the potential release from recycling or disposal of nano-enhanced products.In this work, we investigated the behavior of TiO₂ nanoparticles from incineration of solid paint waste containing these particles. Solid paint debris with and without TiO₂ nanoparticles were treated in a lab scale incineration plant at 950 °C (combustion temperature) and in oxidizing atmosphere. The obtained ashes were also vitrified with additives and the release of Ti was finally evaluated by leaching test. From our incineration lab-scale experiment, we did not observe a release of TiO₂ nanoparticles into the atmosphere, and Ti was attached to the surface of obtained solid residues (i.e. ashes). The characterization of ashes showed that TiO₂ nanoparticles reacted during the incineration to give calcium titanate. Finally, a very low release of Ti was measured, less 1 mg/kg, during the leaching test of ashes vitrified with glass cullet and feldspathic inert. Our work suggests that TiO₂ nanoparticles added in paints may undergo to physicochemical transformation during the incineration, and that Ti found in ashes may be strongly immobilized in glass matrix. Since this conclusion is based on lab-scale experiment, further research is required to identify which nanoparticles will be emitted to the environment from a real-word-incineration system of household hazardous waste.     

Chlorine promotes antimony volatilization in municipal waste incineration

Antimony volatilization in municipal waste incineration was studied. Two municipal waste samples and antimony(III) oxide (Sb₄O₆) were heated to 500°C and 700°C in an air stream in a quartz furnace. The volatilization of Sb₄O₆ occurred more at 700°C that at 500°C. Conversely, antimony volatilization form municipal waste was stronger at 500°C than at 700°C. This implies that antimony from municipal waste is volatilized as chloride instead of oxide. The chlorine sources for antimony chlorination, a gas-phase reaction involving hydrochloric acid and a solid-phase reaction of inorganic chlorine, e.g., CaCl₂, were compared. Only the solid-phase reaction could offer enough active chlorine to induce chlorination of antimony oxide. Received: July 2, 1998 / Accepted: January 28, 1999     

重庆市危险废物市场分析及预测

随着危险废物政策的不断完善,以及重庆市对环境监管力度的不断加大,危险废物收集体系日益健全,危险废物产生、收集、集中处置量将继续增长.现有利用处置设施能力不足,规划的利用处置设施能力与处置缺口出现结构不平衡问题.针对这些问题,对重庆市危险废物的产量及处置现状、现有及规划的危废利用处置设施进行了统计整理分析,并对未来产量进...     

An LCA model for waste incineration enhanced with new technologies for metal recovery and application to the case of Switzerland

A process model of municipal solid waste incinerators (MSWIs) and new technologies for metal recovery from combustion residues was developed. The environmental impact is modeled as a function of waste composition as well as waste treatment and material recovery technologies. The model includes combustion with a grate incinerator, several flue gas treatment technologies, electricity and steam production from waste heat recovery, metal recovery from slag and fly ash, and landfilling of residues and can be tailored to specific plants and sites (software tools can be downloaded free of charge). Application of the model to Switzerland shows that the treatment of one tonne of municipal solid waste results on average in 425 kg CO₂-eq. generated in the incineration process, and 54 kg CO₂-eq. accrue in upstream processes such as waste transport and the production of operating materials. Downstream processes, i.e. residue disposal, generates 5 kg CO₂-eq. Savings from energy recovery are in the range of 67 to 752 kg CO₂-eq. depending on the assumptions regarding the substituted energy production, while the recovery of metals from slag and fly ash currently results in a net saving of approximately 35 kg CO₂-eq. A similar impact pattern is observed when assessing the MSWI model for aggregated environmental impacts (ReCiPe) and for non-renewable resource consumption (cumulative exergy demand), except that direct emissions have less and no relevance, respectively, on the total score. The study illustrates that MSWI plants can be an important element of industrial ecology as they provide waste disposal services and can help to close material and energetic cycles.