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981.
采用吸附法、七铝酸十二钙法、石灰-氯化铝絮凝沉淀法对矿山循环水中高浓度SO24-的脱除进行研究。结果表明:单纯采用吸附法来处理废水,处理后水中的SO24-远不能达到工业用水标准;实验室制备的七铝酸十二钙对SO24-的去除效果不理想,仅为35%,也无法达到工业用水标准;采用石灰-氯化铝絮凝沉淀法处理废水时,当Al3+投加量为420mg/L,pH值为11时,去除率高达90%以上,可使废水中的SO24-质量浓度从1 800 mg/L降至200mg/L以下,完全可循环回用于矿山的选矿和采矿生产。 相似文献
982.
通过颗粒强度测定、扫描电镜分析(SEM)、X射线能谱分析(EDS)和零电点测定(pHPZC)考察改性前后沸石表面特性的变化,考察pH值、沸石投加量、初始氨氮浓度以及温度对吸附过程的影响,并通过吸附等温式和吸附动力学对吸附机制进行描述.经过NaCl改性后的沸石的颗粒强度明显增大,表面更加粗糙,孔径增大,钠离子通过交换作用进入到沸石内部.pH值为7,沸石投加量为8g/L,温度为35℃时吸附效果最好,平衡吸附量(qe)与氨氮初始浓度呈正相关性.Langmuir等温线比Freundlich等温线更适合描述实验数据,最大饱和吸附量为13.210mg/g.吸附动力学符合准二级动力学模型.实验表明NaCl改性沸石能够有效去除水中的氨氮. 相似文献
983.
Linxia Yan Senlin Tian Jian Zhou Xin Yuan 《Frontiers of Environmental Science & Engineering》2016,10(6):5
? The Cu–Ni/γ-Al2O3 catalyst was prepared to study HCN hydrolysis
? On catalyst calcined at 400°C, the HCN removal efficiency reaches a maximum.
? HCN removal is the highest at 480 min at a H 2 O/HCN volume ratio of 150
? The presence of CO facilitates HCN hydrolysis and increases NH 3 production.
? O 2 increases the HCN removal and NOx production but decreases NH 3 production
GRAPHIC ABSTRACT
To decompose efficiently hydrogen cyanide (HCN) in exhaust gas, g-Al2O3-supported bimetallic-based Cu–Ni catalyst was prepared by incipient-wetness impregnation method. The effects of the calcination temperature, H2O/HCN volume ratio, reaction temperature, and the presence of CO or O2 on the HCN removal efficiency on the Cu–Ni/g-Al2O3 catalyst were investigated. To examine further the efficiency of HCN hydrolysis, degradation products were analyzed. The results indicate that the HCN removal efficiency increases and then decreases with increasing calcination temperature and H2O/HCN volume ratio. On catalyst calcined at 400°C, the efficiency reaches a maximum close to 99% at 480 min at a H2O/HCN volume ratio of 150. The HCN removal efficiency increases with increasing reaction temperature within the range of 100°C–500°C and reaches a maximum at 500°C. This trend may be attributed to the endothermicity of HCN hydrolysis; increasing the temperature favors HCN hydrolysis. However, the removal efficiencies increases very few at 500°C compared with that at 400°C. To conserve energy in industrial operations, 400°C is deemed as the optimal reaction temperature. The presence of CO facilitates HCN hydrolysis andincreases NH3 production. O2 substantially increases the HCN removal efficiency and NOx production but decreases NH3 production. 相似文献
984.
Yanxia Zhao Huiqing Lian Chang Tian Haibo Li Weiying Xu Sherub Phuntsho Kaimin Shih 《Frontiers of Environmental Science & Engineering》2021,15(4):58
985.
聚合氯化铝中纳米Al13电荷特性及其混凝效果 总被引:1,自引:0,他引:1
采用聚丙烯酰胺凝胶柱层析法分离纯化聚合氯化铝(PAC)中的Al13形态,并采用Al-Ferron逐时络合比色法和ZATESIZER 3000HSA测定仪对分离所得纳米Al13形态以及AlCl3和PAC进行了分析表征和电荷特性的对比性研究;采用烧杯实验法对3个样品处理实际和模拟水样的混凝效果进行了对比性研究.Al-Ferron逐时络合比色法的结果表明,采用层析法分离可得到含量99%左右的纳米Al13形态;电荷特性和混凝效果研究结果表明纳米Al13形态较其它两者具有更好的除浊、除腐殖酸和脱色效果并且具有更强的电中和能力,因此Al13形态是一种具有较高正电荷和较高的水解稳定性,在给水和废水处理中的一种较为有效的Al形态. 相似文献
986.
CWAO(催化湿式氧化)技术处理COD为2 g/L的亚甲蓝水溶液过程中,实验对18种可溶盐进行了广泛而细致的研究.可溶盐投加量以金属离子计50 mg/L,实验得出Cu^2+、Cr^3+、Fe^2+、Zr^4+具有较好的催化活性;进而对Cr-Cu、Fe-Cu、Zr-Cu组合进行3∶1、1∶1、1∶3的配比实验研究.结果表明配比是1∶1的催化剂催化性能最强,其次是1∶3的配方,再次是3∶1的配方;对较优的催化剂,实验得出了它们催化性能由高到低的排列顺序.铜催化作用下, 在较温和的条件120℃、 1.0 MPa下反应120 min,水样COD去除率达到91.1%,脱色率达到99.92%. 相似文献
987.
絮凝法预处理高浓度垃圾渗滤液的实验研究 总被引:4,自引:0,他引:4
在用絮凝法对CODCr高达19 200~22 500 mg·L-1的垃圾渗滤液进行预处理当中,以垃圾渗滤液的CODCr去除率为考察指标,通过不同混凝剂对CODCr去除效果的比较,确定了最佳混凝剂.通过单因素实验和正交实验确定了最佳混凝剂用量以及最佳反应条件.研究结果表明,采用自制聚合氯化铁絮凝剂在投药比为1 000:3,pH值为10.5左右,搅拌时间为5.0 min,沉降时间为20 min时,能够使垃圾渗滤液的CODCr去除率达到64%以上,减轻了下一步生物处理的负荷. 相似文献
988.
The present investigation examined the detoxifying potential of methanolic herbal extracts, namely the leaf and bark extract of Eucalyptus tereticornis, bark extract of Saraca asoca, Cassia fistula and Withania somnifera in vitro using primary chicken embryo fibroblast (CEF) cells against damaging effects of urea and mercuric chloride (HgCl) (II). The influence of 20?mM urea and 10?µM?HgCl (II) was determined on cell viability or proliferation of cells after treatment with plant extracts. Higher survival rate of primary CEF cells treated with higher concentrations of plant extracts was observed due to their protective ability against urea and HgCl (II). Cassia fistula bark extract (10?mg?mL?1) was found to be most effective against 20?mM urea as it protects 90% of CEF cells whereas W. somnifera protects 86% of the cells within 24?h. After treating cells with10?µM HgCl, W. somnifera and E. tereticornis leaf extracts were found to be more effective among all other extracts as they protect approximately 86% and 70% of CEF cells, respectively, within 24?h. These results indicate that C. fistula and W. somnifera has the highest potential amongst all the five plant extracts for protecting CEF cells against damaging effects of urea and HgCl (II), respectively. 相似文献
989.
Deepmala Joshi Deepak Kumar Mittal Ranjit Kumar Ajai Kumar Srivastav Sunil Kumar Srivastav 《毒物与环境化学》2013,95(9):1581-1588
Mercury (Hg) is a potent nephrotoxin. The aim of this study was to investigate the protective role of Curcuma longa extract and curcumin against HgCl2-induced nephrotoxicity. Male Sprague Dawley rats were administered HgCl2 (12 μmol kg?1, ip; once only) followed by treatment of Curcuma longa extract (200 mg kg?1, po) and curcumin (80 mg kg?1, po) for three days after 24 h of HgCl2 administration. The present results showed that mercuric chloride administration caused an impairment of renal function system which was evident from significant increase in urea, creatinine, uric acid, and blood urea nitrogen concentration in serum. In addition, the swelling in glomerulus and degenerated renal tubules with obstructed lumen was also observed by acute mercuric chloride administration. Treatment with Curcuma longa extract and curcumin was effective in restoring all variables of kidney functions near to control group, which was consistent with kidney histoarchitecture. In conclusion, these results suggest that Curcuma longa extract and curcumin protect against HgCl2-induced nephrotoxicity. This study could be important for the further understanding of mercury toxicity in renal tissues and in the development of better treatments for people and/or animals exposed to the metal. 相似文献
990.
Guy D. Griffin Clay E. Easterly Isidor Sauers Harry W. Ellis Loucas G. Christophorou 《毒物与环境化学》2013,95(2):139-166
Sulfur hexafluoride decomposed by electrical sparks has been found to by cytotoxic to hamster cells when tested in an in vitro cell survival assay, while SF6 shows no cytotoxic activity. Chemical analysis of spark‐decomposed SF6 has identified and quantified the following compounds: SOF2, SO2F2, SF4, SOF4, SiF4, SO2 and HF. Each of these gases, at concentration ranges expected in spark‐decomposed SF6, were tested for cytotoxic activity toward hamster cells. Of the gases showing cytotoxic activity, SO2F2 and SOF4 were similar in activity, as were SOF2 and SF4, while the behavior of SiF4 was different from the rest. None of these individual gases, at concentrations expected in spark‐decomposed SF6, has sufficient cytotoxic activity to account for the cytotoxic effect of spark‐decomposed SF6 observed in our assay system. A four‐component mixture of some of the gases enumerated above (at concentrations overestimating their abundance in spark‐decomposed SF6) was much less cytotoxic than the spark‐decomposed SF6 gas. A mathematical simulation of the cytotoxic activity of a mixture of gases at concentrations found in spark‐decomposed SF6 was made, assuming independent cytotoxic effects from each component. The simulated cytotoxic effect thus computed was less than that seen in spark‐decomposed SF6. Since individual components or mixtures of the major decomposition products do not account for the observed biological activity of spark‐decomposed SF6, this suggests there may be one or more components, present in the spark‐decomposed gas at very low concentrations, which may have a very strong cytotoxic activity. 相似文献