Effect of unburned carbon content in fly ash on the retention of 12 elements out of coal-combustion flue gas

The aim of this study was to evaluate whether unburned carbon particles present in fly ash can help in the retention of S, Cl, Br, As, Se, Cu, Ni, Zn, Ga, Ge, Rb, and Pb out of flue gas during the coal combustion at fluidised-bed power station where the coal was combusted along with limestone. The competitive influence of 10%-25% CaO in fly ashes on the distribution of studied elements was studied as well to be clear which factor governs behaviour of studied elements. Except of S (with significant association with CaO) and Rb and Pb (with major affinity to Al₂O₃) the statistically significant and positive correlation coefficients were calculated for the relations between unburned carbon content and Br (0.959), Cl (0.957), Cu (0.916), Se (0.898), Ni (0.866), As (0.861), Zn (0.742), Ge (0.717), and Ga (0.588) content. The results suggest that the unburned carbon is promising material in terms of flue gas cleaning even if contained in highly calcareous fly ashes.     

外循环三相流化床-人工湿地系统处理渗滤液可行性研究

采用外循环三相流化床-人工湿地的组合工艺对垃圾渗滤液进行处理,主要探讨通过该组合工艺后,出水水质的变化.结果表明,进水COD 4 000 mg.L-1、NH4+-N 300 mg.L-1通过外循环流化床后,COD、NH4+-N分别稳定在1 500 mg.L-1和150 mg.L-1左右;Cd、Zn、Pb含量也均稍有下降,通过人工湿地后,COD、NH4+-N则分别下降到200 mg.L-1和10 mg.L-1左右.Cd、Zn、Pb的含量在分别从进水的0.12 mg.L-1、3.0 mg.L-1和1.4 mg.L-1下降到0.01 mg.L-1、0.5 mg.L-1和0.1 mg.L-1左右.通过不同植被的湿地进行横向比较,发现无论何种植被的湿地,对该组合工艺的处理效果影响不大.     

煤矿开发过程中“三废”治理与资源化利用研究

针对煤矿开发过程中产生的"三废"(主要为矿井水、煤层气、煤矸石)所造成的环境问题,分别对其治理与资源化利用途径进行了叙述.在矿井水方面:从各类矿井水的水质特征出发,阐述了各类矿井水相应的研究进展.在煤层气方面:从煤层气的利用现状入手,分析了煤层气的利用途径和存在的问题.在煤矸石方面:在分析煤矸石特性的基础上,确定其综合利用途径,为煤矸石的开发利用起到了一定的借鉴作用.     

浅议石墨炉原子吸收法测定水中的四乙基铅

用三氯甲烷萃取水中的四乙基铅,直接在石墨炉原子吸收仪上进行测定。结果表明：本方法的相对标准偏差为5．9％,平均回收率在90．4％～108％之间,检出限为1．3×10^-5mg／L,准确度高,精密度好。     

Nutrient concentration variations during Oenanthe javanica growth and decay in the ecological floating bed system

The ecological floating bed system is a natural alternative to technical methods of wastewater treatment and involves complex processes induced by plants or microorganisms in the wastewater. This study aimed to identify nutrient concentration variations during Oenanthe javanica (Blume) DC growth and decay in the ecological floating bed system. Results showed that the third-order polynomial equation was suitable to describe pollutant concentration changes, showing that the effect of O. javanica ecological floating bed system on polluted water could be divided into the purification phase and decay phase. During the purification phase, nutrient concentrations rapidly decreased because O. javanica influenced water microbial communities and water physical parameters (i.e., dissolved oxygen, pH, and temperature), and had a direct uptake of nutrients. However, during the decay phase, nitrogen and phosphorus concentrations in the plant tissues decreased, and these lost nutrients ultimately transferred to water and led to water quality deterioration. Results also showed that the uptake and storage of O. javanica in nutrients were temporary and the plant served only as media of the nutrients removed from the water. Under these circumstances, harvesting was an appropriate intervention to improve the treatment efficiency of O. javanica ecological floating bed system.     

Evaluation of the e ectiveness of horizontal subsurface flow constructed wetlands for di erent media

Two media bed (gravel and Filtralite NR) were tested in a mesocosm to evaluate the removal of organic matter (as chemical oxygen demand (COD)), ammonia (NH4-N), nitrite, nitrate and solid matter (as total suspended solids (TSS)) for a synthetic wastewater (acetate-based) and a domestic wastewater. The use of Filtralite allowed average removal rates (6–16.8 g COD/(m2 day), 0.8–1.1 g NH4-N/(m2 day) and 3.1 g TSS/(m2 day)) and removal e ciencies (65%–93%, 57%–85% and 78% for COD, NH4-N and TSS, respectively), higher than that observed in the experiments with gravel. The applied loads of COD, ammonia, nitrate and TSS seem to influence the respective removal rates but only for the treatment of domestic wastewater with higher correlation coe cients for Filtralite. Regardless the type of media bed and the type of wastewater, nitrate was completely removed for nitrogen loading rates up to 1.3 g NO3-N/(m2 day). There was no evidence of the influence of nitrate loads on the removal of organic matter.     

工业废气在循环流化床锅炉中的掺烧应用

介绍了东方化工厂两台循环流化床锅炉掺烧工业废气改造的背景及原则,叙述了火炬气回收及供气系统、燃气燃烧器、PLC控制三个主要系统的布置、选择、设计等情况,论述了锅炉掺烧火炬气后的安全、掺烧比例的确定、掺烧位置的选择等三个需要重点关注的问题,分析了项目实施后所取得的节能效益、环保效益,是同行业回收利用工业废气,实现节能降耗的一种有效方式,具有很好的参考价值和推广意义。     

城市污水处理厂污泥焚烧处理的探讨

介绍了南通市污泥现状,在分析传统污泥处置方法利弊的基础上介绍了循环流化床污泥焚烧技术。对循环流化床锅炉进行技术改造后,将城市污水处理厂污泥进行焚烧处理,经检测锅炉尾气和灰渣中重金属等污染物指标全部合格。     

悬浮填料好氧移动床反应器挂膜启动方式研究

主要针对好氧移动床处理生活污水挂膜启动方式进行了研究。考察了接种污泥对挂膜启动过程的影响,同时对启动过程中微生物相的变化以及出水中主要污染物随时间的变化情况进行了分析。结果表明：在温度为30～35℃,MBBR1和MBBR2均能在16d左右完成挂膜启动,载体上附着微生物生长稳定时生物膜质量浓度分别达1．2g／L和1．4g／L,接种污泥并不能加速挂膜启动过程。试验还显示,挂膜过程中,CODCr和氨氮的去除率并不是同步提高,好氧异养菌的增殖速度较快,硝化菌的增殖速度较慢。     

A/O＋硅藻强化新工艺在中小型城镇污水处理中的应用总结

采用A/O＋硅藻精土强化工艺水处理技术对城市生活污水进行处理,工程运行结果表明,处理后的废水能够稳定达到《城镇污水处理厂污染物排放标准》（18918-2002）一级A标准。与其它生物处理工艺相比,有其独特的优点。该工艺已成功地应用于永城市污水处理中心,并获得2008年国家重点环境保护实用技术示范工程。而生物浮动床（MBBR工艺）＋硅藻精土强化工艺是在此基础上的改进,并已成功地应用于污水处理。