Suspended solid abatement in a conical fluidized bed flocculator

With the random movement of silica gel beads in a conical fluidized bed, micro-vortices resulting from the fluidization promoted the collision and aggregation of suspended fine kaolin powders. The abatement efficiencies of the suspended fine solids under several hydrodynamic conditions were studied, and a suitable control strategy for operating the conical fluidized bed flocculators was identified. The suspended solids abatement efficiency was found to increase with increasing Camp Number and flocculation time (T), but decreased with the increase of velocity gradient (G) within the range studied in this research (165.1–189.6 s^-1). The abatement efficiencies were all more than 60% at the range of G = 165–180 s^-1 and T = 15–33 s at an initial kaolin solid concentration of 150 mg·L^-1, polymer aluminum chloride dosage of 60 mg·L^-1 and sedimentation time of 20 min. However, the formation of flocs was influenced by the liquid backmixing. Excessive backmixing caused the breakup of flocs and resulted in difficulty for the fine powders to aggregate and sediment to the reactor bottom. The results of the calculated fractal dimension and measured free sedimentation velocity of flocs obtained at different runs showed similar flocs properties, and indicated an easy control strategy for sedimentation of the flocs.     

诱导结晶反应器运行性能研究

以含铜废水为处理对象,将流化床和固定床两种诱导结晶反应器进行对比试验。结果表明:当进水含铜浓度为20 mg/L时,流化床反应器出水含铜量为0～2 mg/L,出水含铜量在0～11 mg/L;利用SEM-EDS可以发现,流化床形成的结晶产物生长致密、晶形明确、产物纯度高,固定床形成的结晶产物在载体表面分布不均、结构疏松,纯度较低。     

利用植物复合床技术处理工业污水

选取风车草、蝴蝶兰、吊兰、小纸莎、菖蒲、香根草6种植物作为人工湿地植物,砾石、活性炭、河沙、砾石+河沙、活性炭+河沙、活性炭+砾石共6种填料作为人工湿地填料,进行不同植物和不同填料组合处理某胶水厂洗釜过程产生的工业废水能力的实验研究.结果表明,在相同的进水水质和水力负荷条件下,从经济成本角度考虑,蝴蝶兰与活性炭+河沙组合较好,对CODCr、氨氮的去除率分别达到95%、99%,出水水质符合DB44/26—2001广东省地方标准水污染物排放限制标准一级标准.该技术处理效果好,操作简单,易维护,适合推广.     

流化床三维电极电催化氧化深度处理焦化废水

研究了以焦粒为粒子电极的流化床三维电极反应器对二级生化处理后的焦化废水进行深度处理。结果表明：采用以焦粒为粒子电极的流化床三维电极反应器能有效降解废水中的有机物,COD去除率依赖于粒子投加量、电流密度、电导率、pH值、曝气量等操作参数的影响。在电导率（以S计）为7.1 m.cm-1,曝气量为160 L.h-1,电流密度（以A计）为48 m.cm-2,pH值为5.0,投加量30 g.L-1时,电解30 min,COD的去除率超过60%,表明流化床三维电极反应器在焦化废水深度处理中有很好工程应用前景。     

几种焦化废水深度处理技术的比较

分别采用Fenton试剂氧化法、固定床离子交换树脂吸附法和流化床磁性树脂吸附法对某焦化厂焦化废水生化工艺出水进行深度处理.试验结果表明:Fenton试剂氧化法处理后出水COD去除率最高达75.4％,色度去除率达89.1％;固定床离子交换树脂吸附法COD去除率为49.4％,色度去除率为96.5％;流化床磁性树脂吸附法COD去除率为58.2％,色度去除率为90.2％.Fenton试剂氧化法COD去除率较高,固定床离子交换树脂吸附法和流化床磁性树脂吸附法色度去除率较高.综合考虑,Fenton试剂氧化法具有更高的工程应用价值.     

内循环流化床光催化反应器的数值模拟与结构优化

设计了一种新型三相内循环流化床光催化反应器并采用气、液两相模拟方法对其进行了结构优化.依据模拟结果,明确了挡板的位置、长度、底部曝气面积等因素对反应器流体行为的影响.结果表明,最优反应器升、降流区横截面积比为1:1,挡板距反应器底部的距离为0.175m,挡板顶部与沉降区底部持平,底部曝气面积为升流区面积的1.2倍.将该反应器进行三相数值模拟,模拟结果表明,固相催化剂在反应器内能够很好地流化,反应器内无明显的死区,其固液分界面低于气液分界面,沉降区能够发挥很好的固液分离效果.     

聚合氯化铁在微絮凝-深床过滤工艺中的应用

以聚铝(PAC)为参照比较研究了聚合氯化铁(PFC)在微絮凝深床过滤工艺中的应用效果.结果表明PFC投药量少(Fe:Al=3:5),其水头滤程可达63h,周期产水率可达1504m³/m²,而PAC的水头滤程为53h,周期产水率为1266 m³/m²;PFC表现出利于延长运行周期,提高产水率等优势.通过截污机理研究表明,PFC具有形成絮体快,与滤料作用迅速,脱水性能好等特点,与PAC相比PFC更适用于微絮凝-深床过滤工艺.     

两种典型生活垃圾焚烧炉烟气中二 相态分布特征

采集了机械炉排焚烧炉和循环流化床焚烧炉两种典型生活垃圾焚烧炉排放烟气样品,应用高分辨气相色谱/高分辨质谱(HRGC/HRMS)同位素内标稀释法分别测定了烟气不同相样品中17种2,3,7,8-位氯取代的PCDDs/PCDFs同类物的含量.结果表明,两种炉型中PCDDs/PCDFs同类物及毒性当量贡献率在冷凝水相中所占的比例均在85%以上,远远高于在滤筒相和XAD-2树脂相中所占的比例,机械炉排炉焚烧排放烟气中∑PCDFs与∑PCDDs的比值为0.77;而循环流化床焚烧排放烟气∑PCDFs与∑PCDDs的比值为5.28.机械炉排炉焚烧烟气三相中OCDD为优势分布,尤其是滤筒相中OCDD的百分比含量高达51.1%.流化床焚烧炉焚烧烟气滤筒、树脂、冷凝水相中没有出现某个单体对总浓度具有绝对优势的贡献.机械炉排焚烧炉和循环流化床焚烧炉排放的烟气中PCDFs的毒性当量贡献最大,尤其是单体2,3,4,7,8-PeCDF对总毒性当量的贡献均在30%以上.     

Occurrence of veterinary antibiotics in struvite recovery from swine wastewater by using a fluidized bed

Antibiotics in wastewater pose pharmacological threats to phosphorous recovery. Recovered struvite particles possessed significantly antibiotic residues. Smaller granules contained much more antibiotics than the larger ones. Organic matters and struvite granulation process exerted significant impacts. Recovering phosphorus from livestock wastewater has gained extensive attention. The residue of veterinary antibiotics in the wastewater may be present in the recovered products, thereby posing pharmacological threats to the agricultural planting and human health. This study investigated antibiotic occurrence in the struvite particles recovered from swine wastewater by using a fluidized bed. Results revealed that tetracyclines possessed significant residues in the struvite granules, with the values ranging from 195.2 mg·kg⁻¹ to 1995.0 mg·kg⁻¹. As for fluoroquinolones, their concentrations varied from 0.4 mg·kg⁻¹ to 1104.0 mg·kg⁻¹. Struvite particles were of various sizes and shapes and displayed different antibiotic adsorption capacities. The data also showed that the smaller granules contained much more antibiotics than the larger ones, indicating that the fluidized granulation process of struvite crystals plays an important role on the accumulation of antibiotics. For tetracyclines, organic matters and struvite adsorption exerted significant impacts on tetracyclines migration. The outcomes underscore the need to consider the residues of antibiotics in resource recovery from wastewater because they exert pharmacological impacts on the utilization of recovered products.     

EGSB处理玉米淀粉生产废水中试研究

研究了厌氧膨胀颗粒 (EGSB)反应器处理玉米生产废水的运行过程现象 ,结果表明 ,液体表面上升流速是影响EGSB反应器效能的重要参数 ,当进水CODCr为 35 0 0～ 6 5 0 0mg L时 ,液体表面上升流速为 1～ 3 5m h时 ,EGSB反应器处理始终保持在 85 %以上 ,污泥经过选择后能够适应EGSB反应器的运行条件。