共查询到19条相似文献,搜索用时 93 毫秒
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利用电石渣液相法制备纳米碳酸钙 总被引:1,自引:1,他引:0
以电石渣为原料、氯化铵溶液为浸取剂、碳酸铵溶液为碳酸化试剂、柠檬酸为晶形控制剂,采用液相法制备了高纯度的纳米级碳酸钙。考察了多种因素对反应的影响,通过X射线衍射仪和扫描电子显微镜对制得的碳酸钙进行表征。确定了最佳的工艺条件:碳酸化过程浸出液Ca^2+浓度为0.6mol/L,柠檬酸与碳酸钙质量比为0.03,碳酸化反应温度为12℃。制得的碳酸钙粒径为40~60nm,为纯净的方解石型晶型。 相似文献
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以磷石膏废渣为原料制备硫酸钙晶须,考察了硫酸钙晶须对模拟含磷废水中磷的去除效果,分析了初始废水pH、初始磷质量浓度、硫酸钙晶须加入量对磷吸附效果的影响,研究了硫酸钙晶须对磷的吸附等温线,同时对吸附机理进行了探讨。实验结果表明:硫酸钙晶须在碱性条件下对磷的去除率较酸性条件下高,且初始废水pH为10时去除效果最佳;最佳硫酸钙晶须加入量为0.03 g/mg(以磷计);在初始废水pH为10、初始磷质量浓度为50 mg/L、硫酸钙晶须加入量为1.5 g/L的条件下,于25 ℃下反应1 h,磷的去除率达到99.16%,上清液TP为0.419 mg/L;与Freundlich模型相比,Langmuir等温吸附模型更适合描述硫酸钙晶须对磷的吸附过程,采用该模型拟合得出25 ℃下磷的饱和吸附量为140.4 mg/g。 相似文献
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次氯酸钙法处理发泡剂生产废水 总被引:6,自引:0,他引:6
采用废漂白液(次氯酸钙)处理发泡剂偶氮二甲酰胺生产废水。废水pH为8~9时,加入质量分数3%~5%的漂白液和1‰PAM絮凝剂,反应2h,沉淀澄清。实验室试验中COD去除率为88%,工业处理试验中COD平均由626mg/L降为105mg/L,去除率为83.2%。该法工艺简单,以废治废,费用低,处理效果好。 相似文献
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利用醋酸废水制取醋酸钙镁盐 总被引:4,自引:1,他引:4
用三辛胺萃取醋酸废水中的醋酸,加入白云石灰乳反萃、可制得环保型除冰剂醋酸钙镁盐(CMA)。研究了萃取剂组成,剂水比,萃取温度,萃取时间,搅拌速度对萃取效率的影响,确定了反萃的操作条件。试验表明:采用该法处理稀醋酸,工艺简单、醋酸利用率高。 相似文献
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Municipal solid waste incinerator by products include fly ash and air pollution control residues. In order to transform these incinerator wastes into reusable mineral species, soluble alkali chlorides must be separated and toxic trace elements must be stabilized in insoluble form. We show that alkali chlorides can be extracted efficiently in an aqueous extraction step combining a calcium phosphate gel precipitation. In such a process, sodium and potassium chlorides are obtained free from calcium salts, and the trace metal ions are immobilized in the calcium phosphate matrix. Moderate calcination of the chemically treated fly ash leads to the formation of cristalline hydroxylapatite. Fly ash spiked with copper ions and treated by this process shows improved stability of metal ions. Leaching tests with water or EDTA reveal a significant drop in metal ion dissolution. Hydroxylapatite may trap toxic metals and also prevent their evaporation during thermal treatments. Incinerator fly ash together with air pollution control residues, treated by the combined chloride extraction and hydroxylapatite formation process may be considered safe to use as a mineral filler in value added products such as road base or cement blocks. 相似文献
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过氧化钙的制备及其在废水处理中的应用 总被引:4,自引:0,他引:4
开发出一种过氧化钙常温合成新工艺。在氯化铵与过氧化氢质量比为10/130、采用稳定剂ⅠA和稳定剂ⅡB的条件下,使氢氧化钙与过氧化氢反应合成过氧化钙,其收率为35.9%,纯度为72.3%。用制得的过氧化钙去除机械工业废水中的重金属离子,在室温、过氧化钙用量0.1%~0.2%、处理时间30min、处理过程中不调整pH的条件下,含锰35.58μg/mL、铜67μg/mL、锌31.3μg/mL、铬43.56μg/mL(均为质量浓度)的废水经一次处理后,锰、铜、锌浓度和pH均达到国家一级水排放标准,铬的一次去除率达到39%以上。 相似文献
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烟气脱硫石膏催化还原为硫化钙的研究 总被引:3,自引:0,他引:3
采用Fe-Ni复合催化剂,在温度650℃条件下即可将烟气脱硫石膏催化还原为硫化钙,还原率达95%以上。研究了反应温度、催化剂加入量及还原气体含量因素对还原反应的影响。 相似文献
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Daizhou Zhang Guangyu Shi Yasunobu Iwasaka Min Hu Jiaye Zang 《Water, Air, & Soil Pollution: Focus》2005,5(3-6):261-276
Analysis of individual particles collected at Beijing in northern China revealed that particles abundant in calcium (Ca) always
constituted a large fraction of mineral particles in the urban atmosphere. The particles were characterized by cubic morphologies.
The major mineral element in the particles was Ca and few or no other mineral elements were detected. A large number of the
particles were in the range of diameter <1 μm, where common natural mineral particles were rarely detected. The contribution
of the Ca particles to the volume of total mineral particles greatly exceeded that of other mineral particles during non-dust-storm
periods and was comparable to that during dust-storm periods. Reagent film tests showed that particulate sulfate and nitrate
formation on the Ca particles was similar to that on common mineral particles. These results indicate that a large portion
of Ca in the atmospheric particulate matter in Beijing was from anthropogenic sources rather than from natural sources, and
the anthropogenic Ca particles acted as a significant medium for the formation of sulfate and nitrate. Similar particles were
also detected at Qingdao, a coastal city in northern China. Data of a dust storm event showed that Ca-abundant particles from
East China arrived there and moved out of the continent, similarly to Asian dust storm particles, suggesting possible contributions
of anthropogenic Ca even in Asian dust storm samples in the downstream areas. Therefore, Ca may not be a good indicator of
Asian dust from natural sources. However, the Ca particles, due to their unique shapes and elemental compositions, may provide
an indicator for the atmospheric dispersion of anthropogenic particulate matters in East Asia. 相似文献
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结合我国电石法聚氯乙烯生产行业的发展现状,提出了采用低汞触媒替代高汞触媒以降低汞消耗、开发高效除汞器以提高脱汞效率、深度解吸废盐酸以解决汞转移问题、深度处理含汞废水以实现综合利用、优化工艺控制以降低汞触媒消耗、改善防护措施以减轻汞扩散等汞污染防治工作的要点。 相似文献
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Calcium alginate hydrogel was prepared and used as a biosorbent for the removal of oil from aqueous solutions. Calcium alginate hydrogel was further chemically modified by esterification with maleic anhydride. The changes in the physicochemical properties of maleic anhydride modified calcium alginate were investigated via multiple techniques (FTIR, SEM, BET and DSC/TGA). Adsorption batch experiments were carried out to compare the oil adsorption capacities of native and modified calcium alginates. Adsorption experiments were carried out as a function of solution pH, temperature and ionic strength to determine the optimal conditions for the adsorption of oil. Equilibrium and kinetic studies were conducted for the modified alginate. Results revealed that the maleic anhydride modification of calcium alginate improved its adsorption capacity towards oil. Higher adsorption capacities of modified alginate were attained at lower temperatures (20 °C), higher ionic strengths (1.0 M NaCl) and within the pH range of 5–9. The oil adsorption data obtained for modified alginate could be better described by the first order kinetic model (R2?=?0.981) and the BET equilibrium isotherm (R2?=?0.984). The maximum monolayer adsorption capacity predicted by the BET model for the modified calcium alginate was found to be 143.0 mg/g. 相似文献
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铜矿酸性废水氧化钙中和处理装置的改造 总被引:2,自引:0,他引:2
介绍了用氧化钙二次中和沉淀法处理铜矿酸性废水的工艺流程、主要设备和处理效果。针对矿山不断开采带来的废水水质变化和处理装置存在的新问题 ,对工艺路线、斜板沉淀池、石灰消和机等进行了改造。改造后的运行结果表明 ,出水水质达到GB8978— 1996二级排放标准 ,节约运行费用 15万元 /a ,沉淀池大修期从 4a延长到 6a ,减少石灰用量 8% ,增加废水处理量 1.5× 10 5m3 /a。 相似文献
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采用磺化聚醚砜中空纤维膜萃取醋酸废水,再用CaO—MgO乳状液反萃取制备醋酸钙镁盐。考察了膜萃取和反萃取的最佳实验条件。单级膜萃取醋酸废水(醋酸质量分数2%)的最佳条件为:水相走管程有机相走壳程(水外油内)逆流、有机相流量与水相流量比1.3、水相流量0.23mL/min,在此条件下萃取率可达74%;采用二级萃取,总萃取率可达95%。反萃取的最佳条件为:采用质量浓度100g/L的CaO—MgO乳状液作反萃取剂,CaO—MgO与醋酸摩尔比1.0:2.0,投料钙与镁摩尔比2.9:7.0,反萃取时间30min,室温,在此条件下反萃取率高于97%。 相似文献
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Jabraili Arezu Pirsa Sajad Pirouzifard Mir Khalil Amiri Saber 《Journal of Polymers and the Environment》2021,29(8):2557-2571
Journal of Polymers and the Environment - In this study, a biodegradable wheat gluten (WG) film containing calcium chloride and nano silica (WG/CaCl2/SiO2) was prepared and the physicochemical... 相似文献