Biosorption behaviors of Cu, Zn, Cd and mixture by waste activated sludge

Biosorption of heavy metal ions, such as Cu²⁺, Cd²⁺ and Zn²⁺, was carried out using waste activated sludge from municipal sewage treatment plant as adsorption material, and the effects of parameters, such as pH value, temperature, reaction time and sorption duration, were studied in detail. The results indicate that the removal rates of Cu²⁺, Zn²⁺ and Cd²⁺ with low concentration are 96.47%, 80% and 90%, respectively, adsorbed by waste activated sludge. Little effect of dosage of activated sludge on the adsorption of Cu²⁺ and more effects on the adsorption of Zn²⁺ and Cd²⁺ are observed. Little effect of temperature is observed, while pH value and adsorption time exert important influence on the sorption process. The adsorption behaviors of heavy metal ions all have parabolic relationships with pH value. The optimum pH value is between 6 and 10, and the optimum adsorption time is 1 h. In single heavy metal ion system, the sorption processes of Cu²⁺, Zn²⁺ and Cd²⁺ are in accordance with Freundlich model, which indicates that it is suitable for the treatment of these three heavy metal ions using intermittent operation. In addition, the sorption capacity of the sludge for Cu²⁺ is preferential to the other two ions.     

渣油胶体稳定性与热反应生焦性能关系的研究

利用混合物粘度法对辽河减压渣油(LHVR)、俄罗斯M100(M100)的胶体稳定性进行研究,其胶体稳定性参数分别为0.802和0.287。对两种渣油的生焦性能进行研究,在相同的反应温度(380℃),反应时间达到90min时,LHVR和M100的生焦率分别为28.40%和11.05%。将质量分数为0.5%的碱性添加剂注入到M100中,反应时间为90 min时,生焦率为3.07%。结果表明,生焦诱导期后,渣油胶体稳定性与其生焦性能之间不存在对应关系,其生焦率的大小主要取决于原料的康氏残炭值,碱性添加剂能够改变渣油中分散体系的稳定性,从而降低生焦率,改善产品分布。     

随机环境下的幂变换门限ARMA-ARCH模型的极限行为

提出了随机环境下的幂变换门限自回归滑动平均自回归条件异方差模型,得出了其以几何速率收敛的充分条件．     

均质土中部分埋入粘弹性桩的瞬态波动响应

基于回传射线矩阵法,得到均质土中部分埋入粘弹性桩在单位脉冲作用下的桩顶速度导纳,然后利用Fourier逆变换和卷积定理得到了在瞬态半正弦激振力作用下的桩顶速度时域响应,与全埋入粘弹性桩作对比,分析桩身材料阻尼、外露桩长、桩侧土阻尼和刚度及桩底土阻尼和刚度对桩顶速度导纳和反射波的影响.结果表明:桩材料阻尼、外露桩长、桩侧土阻尼和桩底土阻尼对桩顶频域及时域速度响应有显著影响;桩侧土刚度和桩底土刚度只对速度导纳曲线的低频部分有影响,且桩底土刚度对导纳曲线的相位和反射波的形状及幅值有显著的影响.     

Cd2+-H2O系羟合配离子配位平衡

根据配位化学热力学平衡原理,绘制了Cd^2＋-H2O系配合离子浓度pc-pH图、镉羟合配离子分率αn-pH图及Cd（OH）2条件溶度积pKS-pH图。pc-pH图描述了Cd（OH）2（s）溶解平衡时,镉的总离子平衡浓度与pH的关系。当pH为9.84～13.31时,Cd（OH）2的溶解度最小;αn-pH图指出了各种羟合配离子分率与pH关系,每种羟合配离子都对应有其存在的最佳pH范围。Cd（OH）2（s）的条件溶度积pKS-pH图表明：当pH值在9.5～10.5范围内,Cd（OH）2（s）的条件溶度积最小。研究结果可为中和水解法去除废水中镉等技术提供理论依据。     

Biosorption behaviors of Cu~(2 ),Zn~(2 ),Cd~(2 ) and mixture by waste activated sludge

1Introduction Waste activated sludge is the by-product of sewage treated by activated sludge process.According to incomplete statistic,in China sewage discharge amount is4.474×107m3/d[1],and there are more than100sewage treatment plants with different sc…     

基于ADuC812的多功能脉冲氩弧焊电源控制系统研究

介绍了以ADuC812为控制核。的逆变多功能脉冲氩弧焊接控制系统，及其软件调试和硬件设计的特点分析了整个控制系统的结构、特点和原理，实现了众多规范参数的数字化设置、调节和控制．改善了人机交互性能。实验表明：该控制系统能够实现对焊接规参数的精确控制，为实现精密焊接奠定了基础。     

基于信道预测技术的闭环发射分集研究

利用瞬时信道信息去实现MIMO系统的自适应传输,需要发射机和接收机能准确地获得当前信道信息.但随着移动通信系统载波频率的提高和移动台运动速度的增加,信道时变性增加,对于快衰落信道,通过信道估计准确获得当前信道信息是不可能的.解决这个问题的一个有效办法就是信道预测.提出将SISO系统中的信道预测技术引入到MIMO系统,结合闭环发射分集,给出预测算法,通过仿真给出性能比较,表明在快衰落信道中,它能更好地将链路自适应地快速调整到信道的真实条件,提高整个系统的性能.     

Main influence factors on desulfurization of coal by sulfolobas

1　INTRODUCTIONHighsulfurcoalwhichletsoutpoisonousandharm fulgassuchassulfurdioxideintheprocessofcoalcom bustion ,isamainfactortoform greatareaacidrainandoccupiesonethirdreservesoftotalcoalinChina .Manhaspaidmuchattentiontoseriousenvironmentpollutionmadebysulfurincoalandsearchedforaspeed ,low costandeffectivetechnologyofdesulfurizationwhichhasbecomeasignificantenvironmentprotectiontasknowadays[1] .Coaldesulfurizationcanbesortedintofore burning ,aflame burningandafter burningbyburningproce…     

Optimization of efficient stable reagent of alkaline thiourea solution for gold leaching

1　INTRODUCTIONThiourea ,asanontoxic goldleachingreagentsubstitutingcyanide ,hasattractedtheinterestofmanyresearchersallovertheworldsincethedissolu tionofgoldinthioureasolutionwasfirstreportedin194 1,andaseriesofstudiesonthetheoryandtech nologyforleachinggoldbythioureahavebeencon ducted[1 3] .Mostreportson golddissolutioninthioureasolutionwereconcernedwithacidicmedia .Itwasdifficultforgoldtodissolveinalkalinesolutionbecauseofthepassivationofelementsulfurproducedbytheirreversibledecompositi…