Performance of biotrickling filters for hydrogen sulfide removal under starvation and shock loads conditions

In the industrial operation of biotrickling filters for hydrogen sulfide (H₂S) removal, shock loads or starvation was common due to process variations or equipment malfunctions. In this study, effects of starvation and shock loads on the performance of biotrickling filters for H₂S removal were investigated. Four experiments were conducted to evaluate the changes of biomass and viable bacteria numbers in the biotrickling filters during a 24-d starvation. Compared to biomass, viable bacteria numbers decreased significantly during the starvation, especially when airflow was maintained in the absence of spray liquid. During the subsequent re-acclimation, all the bioreactors could resume high removal efficiencies within 4 d regardless of the previous starvation conditions. The results show that the re-acclimation time, in the case of biotrickling filters for H₂S removal, is mainly controlled by viable H₂S oxidizing bacteria numbers. On the other hand, the biotrickling filters can protect against shock loads in inlet fluctuating H₂S concentration after resuming normal operation. When the biotrickling filters were supplied with H₂S at an input of lower than 1700 mg/m³, their removal efficiencies were nearly 98% regardless of previous H₂S input. Project supported by the Foundation for Society Development of Jilin Province (No. 20080412-1), the Education Research Foundation for Science and Technology Development of Jilin Province, and the Foundation for Doctor Research in Northeast Dianli University of Jilin Province (No. BSJXM-200710), China     

Personal Review： Sources of sulfide in waste streams and current biotechnologies for its removal

Sulfide-containing waste streams are generated by a number of industries. It is emitted into the environment as dis- solved sulfide (S2- and HS-) in wastewaters and as H2S in waste gases. Due to its corrosive nature, biological hydrogen sulfide removal processes are being investigated to overcome the chemical and disposal costs associated with existing chemically based removal processes. The nitrogen and sulfur metabolism interacts at various levels of the wastewater treatment process. Hence, the sulfur cycle offers possibilities to integrate nitrogen removal in the treatment process, which needs to be further optimized by appropriate design of the reactor configuration, optimization of performance parameters, retention of biomass and optimization of biomass growth. The present paper reviews the biotechnological advances to remove sulfides from various environments.     

Carrier phase shifted SPWM based on current sourced multi-modular converter for active power filter

A novel current-source active power filter(APF)based on multi-modular converter with carrier phase-shifted SPWM(CPS-SPWM)technique is proposed.With this technique,the effect of equivalent high switching frequency converter is obtained with low switching frequency converter.It is very promising in current-source APF that adopt superconducting magnetic energy storage component.     

Carrier phase shifted SPWM based on current sourced multi-modular converter for active power filter

INTRODUCTION iout = i1 (4) Active power filter (APF) (Grady et al., 1990) The resulting iout is sinusoidal and high quality.is a power conversion system for compensating the In this way, APF could provide the harmonic cur-harmonic and reactive power from the nonlinear rent, which is an essential requirement of theload.…     

地震资料F-K滤波去除相干噪声综合性实验

为了满足卓越石油工程师培养需求,实现勘查技术与工程专业核心课程"地震资料数字处理方法"理论学习与实践应用的一体化,针对课程中滤波去噪这一关键教学内容开展了地震资料F-K滤波去除相干噪声的综合性实验探索.首先,以解决地震资料处理实际应用问题为导向确定了实验设计目的;其次,在巩固方法原理前提下设计了融合验证性模块和应用性模...     

内循环吹气吸收法测定沉积物中硫化物含量研究

酸性可挥发硫化物(AVS)是沉积物污染的一项重要指标。在吹气吸收法和冷扩散法基础上,自行设计内循环吹气吸收实验装置用于沉积物中AVS的测定,讨论了流量、时间、温度、含量对测定结果的影响。实验结果表明:内循环吹气吸收法具有装置简单、操作简便、反应时间短、准确度高等优点。实际测定了沉积物样品,回收率95%以上,该方法更适合沉积物AVS的常规测定。     

基于卡尔曼滤波的一级倒立摆LQR控制研究

倒立摆系统的输出不可避免地受到系统噪声和量测噪声的影响,应用卡尔曼滤波对系统输出作最优估计,可以有效地提高系统的鲁棒性。文中给出了卡尔曼滤波应用条件,对单一LQR调节器系统和前置卡尔曼滤波的LQR调节器系统作了仿真对比。并应用前置卡尔曼滤波的LQR调节器成功稳定了一级倒立摆系统。     

FIR数字滤波器的Matlab实现

介绍了FIR数字滤波器的设计方法,提出了一种利用Matlab中的FDATOOL及Simulink工具箱进行FIR数字滤波器设计及仿真的方案。结果表明:采用本方案设计数字滤波器快速简单,可靠性高,符合技术指标要求。     

基于PSPICE的二阶压控电压源低通滤波器仿真实验研究

在教学中,为了有效地将信号与系统、模拟电路的相关知识联系起来,采用PSPICE仿真软件中电路图与系统函数两种分析方法,对二阶压控电压源低通滤波器进行了仿真实验研究。分析了滤波器的Q值和RC滤波电路中的电阻和电容对幅频特性的影响,以方波作为输入信号,对输入/输出的波形及频谱进行了分析,分析结果与理论计算基本一致。该方法有利于学生进一步理解信号、系统和电路三者之间的关系。     

Extracting Moving Objects Based on Morphological Motion Filter

This paper presents a new approach to the extraction of a moving object from video sequence.The method is based on morphological motion filter using connected operator and a propsed new filtering criterion.The morphological motion filter aims to detect motion which is distinct from that of the background,and thereby locates independently moving physical objects in the secnes.Experiments show that the algorithm can extract object from moving backgrounds efficiently.     

基于集总参数电路过渡的微带低通滤波器设计

从集总参数滤波器电路设计出发,应用Richards变换方法和Kuroda规则,讨论了由集总参数电路向分布参数电路转化的具体过程,从而完成紧缩结构的微带低通滤波器设计。采用微波仿真软件对所设计的微带电路进行分析,并对设计电路的参数进行了测试。     

基于MATLAB的有源电力滤波器控制设计研究

应用MATLAB7.0中的SIMULINK仿真软件对有源电力滤波器系统进行数学建模,通过分析、比较有三相负载电流的输出波形,可检测到其线路中电流的畸变率从原来的28.87％下降至7.83％,证明本次所设计的有源电力滤波器系统能够抑制电网的谐波,说明了有源电力滤波器的谐波抑制和无功补偿的设计可以达到较好的效果,此设计具有一定的实际意义与工程实现价值.     

基于二阶异常位模型的重力异常畸变级联Kalman滤波校正方法

借助基于二阶高斯-马尔可夫异常位模型的重力异常协方差函数,得到了海洋重力测量中重力异常信号的状态方程．结合实际重力仪的系统状态方程和系统量测方程,提出了级联卡尔曼滤波方法,并将其应用于重力异常畸变信号的校正处理中．在信号处理过程中,首先采用卡尔曼逆滤波恢复含高频干扰的重力异常,然后采用自适应卡尔曼滤波,以重力异常状态方程为系统方程估计实际重力异常值,并与单一卡尔曼逆滤波器的处理结果进行了对比分析．仿真和试验表明,级联卡尔曼滤波方法和单一卡尔曼逆滤波都能在一定程度上减小重力异常信号的畸变,但在相同背景条件下,级联卡尔曼滤波方法的性能优于单一逆卡尔曼滤波．     

基于锥形光纤滤波器的C波段宽带可调谐掺铒光纤激光器

利用熔融拉锥技术制作了光纤M-Z干涉滤波器.将该滤波器放入Sagnac滤波器,构建了新型的可调谐滤波器.最后利用该Sagnac滤波器,制作了C波段宽带可调谐掺铒光纤激光器.实验结果表明：激光器的调谐范围超过40 nm,各激光光谱的平坦度低于2 dB,激光的旁模抑制比超过50 dB,而激光的3dB线宽小于0.1 nm.     

混合Kalman滤波器与Chamshift人脸跟踪算法的研究

文章通过Kalman滤波器预测由Camshift算法检测到的人脸窗1：7在下一帧图像可能出现的位置,进行下一帧图像的人脸跟踪．其中,Kalman滤波器的使用克服了单纯使用Cam-shift跟踪在遮挡或者丢失跟踪物体的不足,可以大大提高人脸跟踪的正确率．     

基于CMAC神经网络和Kalman滤波器的三维视觉跟踪

采用Kalman滤波器来预测图像特征点的位置，然后在其周围建立图像处理窗口，以达到减小特征点搜索区域及提高图像处理速度的目的．根据基于图像的视觉伺IBVS（image based visual servoing)的原理，在视觉伺服控制环中加入CMAC(cerebellar model articulation controller)神经网络来实现从图像空间的误差信号向输入空间的控制信号的非线性映射，从而避免了图像雅可比矩阵的不断调整及其复杂的求逆过程．模拟结果表明：采用Kalman滤波器能有效预测特征点的位置，同时采用CMAC神经网络能实现在线有导师学习，末端执行器能较好地对目标物体进行跟踪．     

基于单片机的移动机器人实验研究

设计了基于单片机控制的红外导航移动机器人,通过超声波测距来感知机器人的环境信息,利用微波和红外发射装置进行通信,机器人采集到红外信号后,调整路径,实现红外跟踪和自主定位,每个环节的电路均在实验中得到验证,为进一步深入研究机器人技术搭建了一个基础的实验平台。     

基于均值移动重要性采样的粒子滤波人脸跟踪算法

针对condensation目标跟踪算法中用先验转移概率作建议分布函数时没有充分考虑最新观测信息的缺点,提出了一种基于均值移动重要性采样的粒子滤波人脸跟踪算法.算法首先利用均值移动跟踪器粗略定位人脸目标,然后再用此跟踪结果去构造建议分布函数进行粒子传播.由于通过该方法所构造的建议分布函数中包含了最新的观测信息,所以它可以使大多数粒子点都能分布在真实状态区域周围,进而提高了粒子传播的准确性.人脸跟踪结果表明,该算法的跟踪性能明显优于标准condensation方法.     

基于高频增强滤波的光学图像识别谱面增强

在实时联合变换相关器中,由于电寻址液晶透过率较低,造成功率谱对比度比较低,相关峰强度太弱,甚至得不到相关峰.应用高频增强滤波处理技术对功率谱进行滤波处理,能有效提高功率谱对比度,增加信息量,得到较好的相关峰.实验结果证明该方法可行,产生的相关点亮度大幅提高,有利于目标的识别和定位,并给出高频增强滤波参数的选取方法.     

基于一种新的缺陷地结构的低通滤波器的设计

A novel defected ground structure （DGS） for the microstrip line is proposed in this paper. The DGS lattice has more defect parameters so that it can provide better performance than the conventional dumbbell-shaped DGS. Selectivity is improved by 97.2% with a sharpness factor of 24.6%. The method is applied to the design of a low-pass filter to confirm validity of the proposed DGS.