气浮净水技术研究及进展

本文系统总结了目前气浮净水技术的研究现状,着重阐述了溶气气浮机理及气浮池的设计、影响气浮效果的因素、气浮技术的评价及应用现状,同时对有关溶气气浮技术的模型及新概念,以及溶气气浮技术的发展方向进行了论述。     

Highly efficient P uptake by Fe3O4 loaded amorphous Zr-La (carbonate) oxides: Electrostatic attraction, inner-sphere complexation and oxygen vacancies acceleration effect

Bimetallic oxides composites have received an increasing attention as promising adsorbents for aqueous phosphate (P) removal in recent years. In this study, a novel magnetic composite MZLCO was prepared by hybridizing amorphous Zr-La (carbonate) oxides (ZLCO) with nano-Fe₃O₄ through a one-pot solvothermal method for efficient phosphate adsorption. Our optimum sample of MZLCO-45 exhibited a high Langmuir maximum adsorption capacity of 96.16 mg P/g and performed well even at low phosphate concentration. The phosphate adsorption kinetics by MZLCO-45 fitted well with the pseudo-second-order model, and the adsorption capacity could reach 79% of the ultimate value within the first 60 min. The phosphate adsorption process was highly pH-dependent, and MZLCO-45 performed well over a wide pH range of 2.0-8.0. Moreover, MZLCO-45 showed a strong selectivity to phosphate in the presence of competing ions (Cl⁻, NO₃⁻, SO₄²⁻, HCO₃⁻, Ca²⁺, and Mg²⁺) and a good reusability using the eluent of NaOH/NaCl mixture, then 64% adsorption capacity remained after ten recycles. The initial 2.0 mg P/L in municipal wastewater and surface water could be efficiently reduced to below 0.1mg P/L by 0.07 g/L MZLCO-45, and the phosphate removal efficiencies were 95.7% and 96.21%, respectively. Phosphate adsorption mechanisms by MZLCO-45 could be attributed to electrostatic attraction and the inner-sphere complexation via ligand exchange forming Zr/La-O-P, -OH and CO₃²⁻ groups on MZLCO-45 surface played important roles in the ligand exchange process. The existence of oxygen vacancies could accelerate the phosphate absorption rate of the MZLCO-45 composites.     

溶济萃取法处理含硫酸及硫酸盐的废水

采用溶剂萃取法处理含硫酸及硫酸盐的工业废水，主产优质农用硫酸钾，副产氯化铵和氮钾复合肥，整个工艺过程基本无三废排放，实现了对该废水的综合有效治理。     

Performance and bioparticle growth of anaerobic baffled reactor (ABR) fed with low-strength domestic sewage

We investigated the performance of a 15.3 L capacity anaerobic baffled reactor (ABR) toward the treatment of low-strength domestic wastewater. The start-up period of the ABR was finished within approximately 130 days at a temperature below 25°C. The average COD_Cr in the effluent was 165 mg·L^-1, and the corresponding COD_Cr removal efficiency of the ABR was 52.3%. During the third stage (from day 130 to day 233) of ABR operation, the average COD_Cr in the effluent reached 71 mg·L^-1, which meets the secondary discharge requirement of the Integrated Wastewater Discharge Standard (GB 18918-2002, China). Moreover, partial microbial separation was observed along the five ABR compartments through scanning electron microscopic images. The geometric mean diameter of bioparticles in the five compartments increased from 0.050 mm to 0.111, 0.107, 0.104, 0.110, and 0.103 mm during the start-up stage. After operation for 179 days, the corresponding diameters further increased to 0.376, 0.225, 0.253, 0.239, and 0.288 mm, respectively. The fractal dimensions of the bioparticles indicated that these particles have smoother surfaces and more compact structures during ABR operation. Morphological analysis of the bioparticle sections demonstrated that the bioparticles have a pore volume of 30%–55%. The highest porosity was observed for the bioparticles in the second ABR compartment, whereas the lowest fractal dimension of bioparticle section was observed in the fifth compartment.     

颗粒活性炭吸附染料的类分形动力学特征的研究

建立了复杂分子吸附反应时指数h与分形子谱维数ds、分形介质的表面分形维数Ds 的关系式.对吸附动力学数据的模拟表明,不同温度下6种染料在颗粒活性炭表面的吸附过程符合非线性动力学.吸附速率一般随着温度的升高而增加,反应活化能在0 2 0～1 75kJ·mol- 1 之间.上述反应为快速反应.进一步分析表明,该吸附过程具有类分形动力学特征,吸附反应的逐时速率系数k与反应时间t呈指数关系;相应的分形子谱维数ds<2 .随着染料的初始浓度的增加,ds 也随之增加,而h和k0 值通常会随之降低.吸附3种酸性染料时,h和k0 值在本实验的温度范围内均随着温度的升高而增加;其它3种直接性染料也大都呈现h随着温度的升高而增加的趋势.上述吸附反应中有效反应级数x也与ds、Ds 有关,呈现分数反应级数     

基于贝叶斯网络气化炉供料系统风险分析

为解决当前气化炉供料系统风险分析不完善的状况,提出1种基于贝叶斯网络和HAZOP的风险分析模型。以某单日投煤量3 000 t级气化炉煤化工企业实际运行情况为研究对象,应用HAZOP法对其进行风险分析,并将HAZOP分析结果中各偏差产生原因转化为贝叶斯网络节点;考虑到先验知识的缺乏问题,引入Leaky Noisy OR模型,通过文献资料和相关领域专家经验知识获得先验概率,并利用贝叶斯网络进行风险分析,找出系统运行的薄弱环节。结果表明:未知因素影响会使各节点的后验概率值差异性降低,更加贴合实际;在引入未知因素影响后,系统运行薄弱环节并未发生改变。     

基于疲劳累积破坏机制的储罐结构动力可靠度分析

针对随机风载荷作用下储罐结构动力可靠性问题,以300 m3的中小型立式低温储罐为研究对象,利用AR模型进行数值模拟得到风载荷的脉动风速时程与脉动功率谱密度函数。采用ANSYS建立储罐三维有限元模型,并对储罐进行动力学分析,计算出储罐结构的随机响应,进而求出随机风载荷作用下储罐结构动力可靠性所需全部数字特征,最后利用疲劳累积损伤机制计算得到储罐的动力可靠度。结果表明:假设结构强度不随时间退化,前5 a动力可靠度基本保持不变,随着使用年限的延长,动力可靠度下降速度明显增大。研究方法可为储罐的动力可靠性及寿命预测提供一定的理论依据。     

Effects of acid,acid-ZVI/PMS,Fe(Ⅱ)/PMS and ZVI/PMS conditioning on the wastewater activated sludge(WAS)dewaterability and extracellular polymeric substances(EPS)

The effects of four conditioning approaches:Acid,Acid-zero-valent iron(ZVI)/peroxydisulfate(PMS),Fe(Ⅱ)/PMS and ZVI/PMS,on wastewater activated sludge(WAS) dewatering and organics distribution in supernatant and extracellular polymeric substances(EPS) layers were investigated.The highest reduction in bound water and the most WAS destruction was achieved by Acid-ZVI/PMS,and the optimum conditions were pH 3,ZVI dosage 0.15 g/g dry solid(DS),oxone dosage 0.07 g/g DS and reaction time 10.6 min with t...     

模拟消落带水华暴发行为的数值沙堆模型

以长江最大支流汉江近年来水华污染的现场资料为例,通过氮磷浓度、水温、流速和光照等实测数据构建了消落带开放水域环境体系的数值沙堆模型,描述了藻类生长及水华暴发的动力学机制;利用数值沙堆系统崩塌行为反映出的频率-尺度幂律关系作为判断消落带水域是否暴发水华以及规模大小的依据,采用有限尺度标度分析从不同侧面验证了水华暴发系统的自组织临界性,并揭示出各种拟合参数与水华暴发规模之间的定量关系.研究表明,沙堆模型如果存在良好的幂律关系,相应的消落带水域将暴发水华,且幂律指数越大,水华污染程度越严重.     

低温等离子体技术处理挥发性有机物

介绍了低温等离子体技术在处理挥发性有机物(VOCs)的研究现状和成果;探讨了低温等离子体技术的发展趋势.