Properties and effect of forming sewage sludge into lightweight ceramics

In this work we investigated the chemical, thermal and toxic properties of dried sewage sludge (DSS), the preparation and properties of lightweight sludge ceramic (LSC) and the mechanisms of action of the organic and inorganic foaming agents (OFAs and IFAs). The chemical components and thermal properties of the raw materials were studied by Energy Dispersive X-ray Detection (EDX) and Thermogravimetric Analysis and Differential Scanning Calorimetry (DSC/TGA). The mineral phases of the raw materials and the formed ceramics were determined by X-ray Diffraction (XRD). The leaching characteristics of heavy metals were investigated with Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). Different ratios of DSS and clay were mixed and pressed into raw pellets. After drying and preheating treatment, the raw pellets were sintered at 1150°C for 10 min. The physical properties of LSC (50 wt% DSS added) were tested. The results showed that when the addition of DSS was above 50 wt%, LSC began to shrink, and a maximum density occurred. The environmental safety of LSC was satisfactory. XRD showed that some new mineral phases formed in the LSC. Observation of the microstructure by Scanning Electron Microscope (SEM) indicated that the body of LSC was porous.     

Coagulation behavior and floc properties of compound bioflocculant-polyaluminum chloride dual-coagulants and polymeric aluminum in low temperature surface water treatment

This study was intended to compare coagulation behavior and floc properties of two dualcoagulants polyaluminum chloride–compound bioflocculant(PAC–CBF)(PAC dose first) and compound bioflocculant–polyaluminum chloride(CBF–PAC)(CBF dose first) with those of PAC alone in low temperature drinking water treatment. Results showed that dualcoagulants could improve DOC removal efficiency from 30% up to 34%. Moreover, CBF contributed to the increase of floc size and growth rate, especially those of PAC–CBF were almost twice bigger than those of PAC. However, dual-coagulants formed looser and weaker flocs with lower breakage factors in which fractal dimension of PAC–CBF flocs was low which indicates a looser floc structure. The floc recovery ability was in the following order:PAC–CBF PAC alone CBF–PAC. The flocculation mechanism of PAC was charge neutralization and enmeshment, meanwhile the negatively charged CBF added absorption and bridging effect.     

用煤矸石制备聚合氯化铝铁絮凝剂的研究

为了探讨从煤矸石中浸出铝铁的原理和工艺,利用透射电镜,红外光谱和Ｘ－射线衍射分析技术对ＰＡＦＣ的结构进行了表征,试验了ＰＡＦＣ处理实际工业废水的效果。结果表明,用煤矸石制取ＰＡＦＣ是可行的;制备出的ＰＡＦＣ是聚合铝铁的复合产物。     

有机改性剂对水中有机氯农药提取效率的影响研究

通过有机改性剂在液液萃取和固相萃取条件下水中有机氯农药的提取效率比对分析,首次探讨了有机改性剂对水中有机氯农药提取效率的影响。结果表明,(1)液液萃取前处理水样中不加有机改性剂、固相萃取前处理水样中添加一定量有机改性剂时,水中有机氯农药的提取效率较高;(2)采用正交实验优化水中有机氯农药固相萃取的提取效率实验表明,有机改性剂添加量对其影响大于有机改性剂种类对其影响;最佳优化方案为水样中添加1%甲醇时,提取效率最高。     

聚合铝基复合絮凝剂的电荷特性及絮凝作用

以具有不同碱化度(B)的聚合氯化铝(PAC)和二甲基二烯丙基氯化铵均聚物(PDMDAAC)为原料,制备出了系列PAC-PDMDAAC,采用微电泳技术研究了其电动特性,初步试验了处理黄河水的絮凝效果.研究结果表明,PAC-PDMDAAC较PAC具有更高的正Zeta电位值与更好的除浊效果.PAC的B值和PDMDAAC质量分数(P)对PAC-PDMDAAC的Zeta电位与除浊效果均有不同程度的影响.     

SJ—20型环境生物样品微波溶样器的研制

研制出了SJ—20型环境生物样品微波溶样器,测定了溶样器的耐压情况,并在实际生物和食品样品的测定中进行了初步应用.结果表明,该溶样器安全可靠,消化速度快,消解完全,对环境基本无污染.     

Performance of bimetallic nanoscale zero-valent iron particles for removal of oxytetracycline

In this study, bimetallic nanoscale zero-valent iron particles(nZVI), including copper/nanoscale zero-valent iron particles(Cu/nZVI) and nickel/nanoscale zero-valent iron particles(Ni/nZVI), were synthesized by one-step liquid-phase reduction and applied for oxytetracycline(OTC) removal. The effects of contact time and initial p H on the removal efficiency were studied. The as-prepared nanoscale particles were characterized by scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS) and X-ray diffraction(XRD). Finally, the degradation mechanisms of OTC utilizing the as-prepared nanoparticles were investigated by using X-ray photoelectron spectroscopy(XPS) and mass spectrometry(MS). Cu/n ZVI presented remarkable ability for OTC degradation and removed71.44% of OTC(100 mg/L) in 4 hr, while only 62.34% and 31.05% of OTC was degraded by Ni/nZVI and nZVI respectively. XPS and MS analysis suggested that OTC was broken down to form small molecules by ·OH radicals generated from the corrosion of Fe0. Cu/nZVI and Ni/n ZVI have been proved to have potential as materials for application in OTC removal because of their significant degradation ability toward OTC.     

The chemical species distribution and transformation of polyaluminum silicate chloride coagulant

The chemical species distributions of polyaluminum silicate chloride (PASC) and polyaluminum chloride (PACl) determined by Al-Ferron complexation timed spectrophotometric and 27Al-NMR methods, respectively, have been compared and analyzed. The experimental results show that the species distribution and transformation of PASC are different from those of PACl, due to the interaction of polysilicic acid and hydrolyzed aluminum species. At the same basicity (B), the contents of, Al(b), Al13 and the monomer species Almono (also determined by 27Al-NMR) in PASC are lower than those in PACl, while the contents of Al(c) and the Alother determined by 27Al-NMR in PASC are higher than those in PACl. The differences between PASC and PACl with respect to these species enlarge as the molar ratio of Al/Si in PASC decreases. Further, in PACl the ratio of Al13 to Al(b) closes to 1.0, indicating that the amount of the two fractions are similar. In PASC, however, such an agreement does not exist at the lower B values and Al/Si molar ratios. When the B value and Al/Si molar ratios increase, however, the amount of Al13 and Al(b) species tends to close. The study findings indicate that polysilicic acid can react with hydrolyzed aluminum species to form an aluminum silicate polymer composite and result in the change in species distribution of PASC.     

纳米Al13的分离方法及混凝效果动态过程的研究

以相同Al13含量、不同浓度的PAC为原料,利用乙醇-丙酮混合溶剂法、SO4^2-／Ba^2 沉淀置换法以及柱层析法分离提纯纳米Al13形态,同时利用Al-Ferron逐时络合比色法、^27Al-NMR等多种现代分析手段进行分析鉴定,比较其分离效果,并采用烧杯实验法和透光率脉动检测技术对Al13形态以及PAC、AlCl3的絮凝效果及絮凝过程中絮集物形成和增长的变化差异作了对比性研究．实验结果表明,乙醇．丙酮混合溶剂法对Al13分离纯化效果最好,分离所得Al13平均粒径大,聚合程度高．柱层析法受柱体积的影响只对低浓度的PAC有较好的分离效果;SO4^2-／Ba^2 沉淀置换法虽具有较好的分离效果,但分离过程有其他杂质离子的加入,影响到产品品质．混凝效果和动态实验结果表明,Al13形态是在絮凝过程中起电中和作用的主要形态,具有较强的除浊及脱色能力,在混凝过程中当絮体受到剪切力的破坏时Al13形态比PAC和AlCl3具有更强重新絮凝的能力．     

聚硅氯化铝混凝剂除油效果的试验

制备不同碱化度和不同Ａｌ／Ｓｉ摩尔比的系列聚硅氯化铝作为混凝剂，实验考察了Ｂ，Ａｌ／Ｓｉ摩尔比及ＰＨ值对除油效果的影响，并考察了ＰＡＳＣ去除ＣＯＤ的效果。结果表明，Ｂ对ＰＡＳＣ混凝除油效果影响较大，随Ｂ值增大，除油效果提高；Ａｌ／Ｓｉ摩尔比对ＰＡＳＣ混凝除油效果影响较小；