Trace Gas Emissions from Biomass Burning from Northeast Region in India—Estimates from Satellite Remote Sensing Data and GIS

Biomass burning associated with shifting cultivation areas from the northeastern region of India is an important source of trace gas emissions in the Southeast Asian region. In the present study, satellite data pertaining to IRS-P4 OCM data and DMSP-OLS has been used to quantify the intensity, areal extent and amount of biomass burnt in the northeastern region states at district level. Trace gas emissions have been quantified both by using IPCC based emission ratios and ground based emission ratios obtained from field based studies. Areal estimates with respect to shifting cultivation areas from IRS-P4 OCM satellite data of 4th April 2000 suggested nearly 112.99 km² of the northeastern region of India affected due to shifting cultivation. In the study, DMSP OLS nighttime data has been used to capture the real time fires during the dry season. The results suggested high amount of fires during the March season when compared to April and May. Using the emission ratios obtained from the ground-based studies and IPCC emission ratios, the emissions for the individual non-CO₂ trace gases have been computed in a GIS framework using the biomass data, combustion factors and emission ratios. Results suggested emissions of 2.063 Mt CH₄, 17.94 Mt CO, 1.419 Mt N₂O, and 51.28 Mt NO _x and 2.643 Mt release of CH₄, 3.7204 Mt CO, 0.145 Mt N₂O, and 8.477 Mt NO _x , respectively, from biomass burning due to shifting cultivation for the year 2000, from the northeastern region in India. The study highlights the importance of Satellite Remote sensing data and GIS in quantifying the trace gas emissions from biomass burning.     

煤气化细渣制备碳硅复合材料吸附去除水中Pb2+

以煤气化细渣为原料制备了高比表面积碳硅复合材料,并利用过硫酸铵对其进行表面改性,用于吸附100.0 mg/L PbCl₂溶液中Pb²⁺。表征结果显示：碳硅复合材料的比表面积为1 347 m²/g,改性后降为474 m²/g;改性后材料表面的羟基、羰基和羧基等含氧基团的含量显著增加。实验结果表明：溶液pH为5时,改性碳硅复合材料对Pb²⁺的平衡吸附量为124 mg/g,Pb²⁺去除率可达98.2%;吸附过程符合准二级动力学模型,以化学吸附为主,伴有物理吸附;吸附过程分为外扩散和内扩散两个阶段,受内扩散控制。     

水力空化-Fenton氧化联合超声吸附处理煤气化废水

采用水力空化-Fenton氧化联合超声吸附处理煤气化废水,考察了单独Fenton氧化及单独水力空化工艺条件,并对Fenton氧化、水力空化和水力空化-Fenton氧化工艺处理过程进行了动力学初探。实验结果表明:在反应时间60 min、废水pH 3.0、Fe~(2+)加入量900 mg/L、H_2O_2加入量3 600 mg/L、空化压力0.4 MPa的条件下,水力空化-Fenton处理煤气化含酚废水的COD和苯酚去除率分别为93.05%和90.29%;进一步采用超声吸附处理后,出水COD和苯酚质量浓度分别为92.9 mg/L和4.5 mg/L,达到GB 8978—1996《污水综合排放标准》三级指标。     

电絮凝技术处理煤气化灰水

采用电絮凝技术处理粉煤加压气化航天炉装置产生的灰水。中试结果显示：灰水经电絮凝一体化装置处理后,出水中总钙和总镁的平均值分别降至180 mg/L和11.1 mg/L,有效抑制了结垢的发生;相对于单一氢氧化钠,碳酸钠和氢氧化钠共同作用的处理效果更好。工业化应用结果表明,电絮凝一体化装置对灰水的总硬度、浊度和悬浮物均有较好的去除效果,其平均去除率分别为32.5%、66.7%和73.0%。采用该技术处理煤气化灰水具有较强的经济性。     

水力空化-O3氧化联合超声吸附处理煤气化废水

采用水力空化-O₃氧化与超声吸附法联合处理煤气化废水。吸附剂以钙基膨润土为原料,经十六烷基三甲基溴化铵改性制得。通过单因素实验分别探讨了水力空化-O₃氧化与超声吸附的适宜处理条件,并在该条件下对废水进行联合处理。实验结果表明：在O₃通量194.4 mg/L、空化时间60 min、入口压力0.4 MPa、废水pH 10.00的优化条件下,水力空化-O₃氧化对COD和苯酚的去除率分别达67.3%和57.5%;在此基础上进一步采用超声吸附法处理废水,在吸附剂投加量0.06 g/mL、超声时间60 min、废水pH 4.00、吸附温度25 ℃的优化条件下,处理后出水中COD和苯酚质量浓度分别降至317.1 mg/L和117.9 mg/L;COD和苯酚的总去除率分别达97.9%和96.6%。     

活性焦吸附—曝气生物滤池处理煤气化废水生化出水

采用活性焦吸附—曝气生物滤池（BAF）工艺对煤气化废水生化出水进行深度处理。在活性焦投加量2 g/L、吸附时间2 h、BAF生化停留时间4 h的条件下,总COD去除率为85.4%,最终出水平均COD为45.2 mg/L,满足后续双膜法回用工艺要求（COD≤50 mg/L）。活性焦对致色的大分子有机物具有较好的吸附效果,吸附后废水的色度从300倍降至60倍,同时耗氧速率加快,可生化性提高。活性焦的吸附以物理吸附为主,吸附出水没有急性毒性。三维荧光光谱显示：各单元对于酚类的去除均有贡献,小分子组分中的酚类几乎全被去除。     

生物质气化发电厂灰渣中微量元素的赋存形态及其析出

分别用Tessier逐级提取形态分离法和模拟酸雨浸提实验,研究了生物质气化发电厂的气化器、淋洗器和旋风分离器底灰中微量元素的赋存形态及其析出规律,探讨了微量元素析出浓度和影响其析出的因素．结果表明,微量元素大部分存在于残渣态,其有机态、Fe-Mn氧化态和碳酸盐结合态的浓度依次减少,可交换态的赋存量极低;元素的析出受浸提液pH值、浸提温度和浸提时间的影响,元素在灰渣颗粒物中的赋存形态及含量的高低也影响元素的释放和析出程度．     

秸杆燃烧中OCS的排放因子和排放估算

建立了痕量羰基硫采样及分析方法。利用低温预捕集和被捕集样直接释放进入分离柱技术,对压缩空气进行采样测定。得出了压缩空气中ＯＣＳ约在２．９４×１０＾－３μｇ／Ｌ,方法精确度以标准误差系数计为±０．７２％,利用此采样及分析方法对实验室规模的生物质封闭燃烧系统,稻草、玉米秸、科杆燃烧中排痕量ＯＣＳ进行了采样分析,得出稻草、玉米秸麦杆燃烧排气中ＯＣＳ的排放量,以排放因子表示分别是：１．８０ｇ／ｔ,２．７５     

生物质能源发展的市场环境培育分析——以湖北省为例

生物质能源作为可再生能源的重要组成部分,其在替代能源、环境保护、减少碳排放,促进农民增效方面具有重要作用。以资源贫乏、能源短缺的湖北省作为生物质能源发展市场环境培育分析的研究对象,具有一定的代表性。通过深入分析生物质能源原料市场、产品市场、技术市场的发展现状,得知生物质能源发展的政策法规不完善、市场保障机制体系不健全、公众能源意识淡薄、投融资体制不顺畅、技术研发创新难是制约其产业发展的主要因素。因此对生物质能源发展的市场环境培育提出3方面建议：在政策法规层面,政府需要制定保护性政策来调控市场,以弥补市场力量的不足,并界定好生物质能源产业的发展方向;在监管体系层面,需要设立严格的生物质能源市场准入门槛和有效的定价机制,防止生物质能源过度发展;在企业经营层面,实施生物质能源企业集群带动战略,提升核心竞争力。     

Effect of impeller type and mechanical agitation on the mass transfer and power consumption aspects of ASBR operation treating synthetic wastewater

The effect of flow type and rotor speed was investigated in a round-bottom reactor with 5 L useful volume containing 2.0 L of granular biomass. The reactor treated 2.0 L of synthetic wastewater with a concentration of 800 mgCOD/L in 8-h cycles at 30 degrees C. Five impellers, commonly used in biological processes, have been employed to this end, namely: a turbine and a paddle impeller with six-vertical-flat-blades, a turbine and a paddle impeller with six-45 degrees -inclined-flat-blades and a three-blade-helix impeller. Results showed that altering impeller type and rotor speed did not significantly affect system stability and performance. Average organic matter removal efficiency was about 84% for filtered samples, total volatile acids concentration was below 20 mgHAc/L and bicarbonate alkalinity a little less than 400 mgCaCO3/L for most of the investigated conditions. However, analysis of the first-order kinetic model constants showed that alteration in rotor speed resulted in an increase in the values of the kinetic constants (for instance, from 0.57 h(-1) at 50 rpm to 0.84 h(-1) at 75 rpm when the paddle impeller with six-45 degrees -inclined-flat-blades was used) and that axial flow in mechanically stirred reactors is preferable over radial-flow when the vertical-flat-blade impeller is compared to the inclined-flat-blade impeller (for instance at 75 rpm, from 0.52 h(-1) with the six-flat-blade-paddle impeller to 0.84 h(-1) with the six-45 degrees -inclined-flat-blade-paddle impeller), demonstrating that there is a rotor speed and an impeller type that maximize solid-liquid mass transfer in the reaction medium. Furthermore, power consumption studies in this reduced reactor volume showed that no high power transfer is required to improve mass transfer (less than 0.6 kW/10(3)m3).