首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
用副产盐酸和劣质高岭土制备聚合氯化铝   总被引:4,自引:0,他引:4  
开发出一种用废盐酸和劣质高岭土生产聚合氯化铝的方法。分别考察了焙烧温度,焙烧时间,盐酸用量以及酸浸时间对铝浸出率的影响。试验结果表明;依照该工艺生产的聚合氯化铝,其各项指标符合GB15892-95标准。  相似文献   

2.
倒极电解法合成聚合氯化铝絮凝剂   总被引:4,自引:0,他引:4  
为减少电解制备絮凝剂过程中的极化现象,用特制的自动倒极电源装置合成聚合氯化铝(PAC)絮凝剂。确定了合成的最佳工艺条件:电解槽电压2V;电流密度6A/dm2;倒极周期1s。与不采用倒极装置相比,在最佳条件下合成PAC时,该装置可明显抑制极化现象。处理模拟水样试验表明,该法制备产品的絮凝效果优于一般电解法制备产品及市售产品的絮凝效果。  相似文献   

3.
聚合氯化铝钙的合成与应用   总被引:4,自引:0,他引:4  
以氧化铝和碳酸钙为原料制备新型的无机高效水处理剂聚合氯化铝钙,研究了合成条件,确定了最佳的工艺参数。实验表明,升高温度有利于产品的合成,在10g铝酸钙粉末中盐酸加人量为70mL,酸溶时间为3h,焙烧反应中氧化铝与碳酸钙的适宜配比为3:2(质量比)。将合成的产品用于高炉煤气洗涤废水处理中,处理后的水质达到国家的排放标准和该厂的循环使用标准。  相似文献   

4.
复合絮凝剂XG-1用于工业废水的处理   总被引:12,自引:0,他引:12  
对利用硅藻土研制出的复合絮凝剂XG-1处理造纸、焦化工业废水进行了研究。试验结果表明:该絮凝剂对造纸、焦化工业废水有很好的处理效果,COD去除率达70%-80%,脱色率大于90%,操作工艺简单,成本低,处理效果优于聚合氯化铝。  相似文献   

5.
研究了以含铝废泥和工业盐酸为原料制备聚合氯化铝的生产工艺,通过对物料配比和反应条件的考察,成功制得了有效含量(以Al2O3计)8%,盐基度50%的符合GB/T 22627—2014《水处理剂聚氯化铝》标准的聚合氯化铝产品。为了提高生产效率,改善生产条件,在传统一步法、两步法生产工艺的基础上,对利用含铝废泥和工业盐酸制备聚合氯化铝的生产工艺加以优化,使得改进后的聚合氯化铝生产工艺,既能实现含铝废泥中铝资源的高效利用,变废为宝,创造了良好的经济效益,又可实现含铝废泥的减量化、无害化处理,保护生态环境,因此,是一种具有实际生产改良意义的聚合氯化铝生产工艺。  相似文献   

6.
铝灰酸溶法制备聚合氯化铝   总被引:1,自引:0,他引:1       下载免费PDF全文
以铝灰为原料采用酸溶法制备了聚合氯化铝(PAC),并通过正交实验优化了PAC制备的最佳工艺参数,并考察了自制PAC对废水COD的去除效果。制备PAC的最佳工艺条件为:m(铝灰)∶V(HCl)∶V(H2O)=10∶20∶40,反应温度85℃,反应时间2.5h,搅拌转速80r/min,熟化时间30h,熟化温度60℃。采用生石灰可高效、经济地调节产品的盐基度,且产品在处理印染废水时COD去除率达64.7%,高于市售同类产品。  相似文献   

7.
粉煤灰制聚合氯化铝铁和白碳黑新工艺   总被引:2,自引:0,他引:2  
采用粉煤灰制备聚合氯化铝铁和白碳黑.该法共分一次酸浸、碱溶、焙烧、二次酸浸4个阶段.实验确定的最佳工艺条件为:一次酸浸阶段酸溶温度100℃,碱溶阶段m(氢氧化钠):m(活化高硅渣)=0.6,二次酸浸阶段m(碳酸钠):m(灰渣A)=0.8、盐酸质量分数20%.在此条件下Fe~(3+)和Al~(3+)的总浸出率分别为96.54%和86.67%.主要产品聚合氯化铝铁的质量符合GB15892-2003<水处理剂聚氯化铝>的标准;产品白碳黑的质量符合GBl0517-89<沉淀二氧化硅>的标准.  相似文献   

8.
二甲基二硫代氨基甲酸钠处理锌冶炼含镉废水   总被引:1,自引:0,他引:1       下载免费PDF全文
何厚华  朱挺健  刘泽  陈曼  王檑 《化工环保》2015,35(3):293-296
以二甲基二硫代氨基甲酸钠(福美钠)作为脱镉螯合剂,以聚合氯化铝作为絮凝剂,脱除含镉废水中的Cd2+。在考察福美钠加入量、搅拌时间、聚合氯化铝加入量、沉淀时间等工艺条件对Cd2+脱除效果影响的单因素实验的基础上,采用正交实验对工艺参数进行进一步优化。实验结果表明:在福美钠加入量为1.0 g/L、搅拌时间为20 min、聚合氯化铝加入量为0.2 g/L、沉淀时间为5 h的最佳工艺条件下,采用福美钠处理初始Cd2+质量浓度为100 mg/L的锌冶炼含镉废水,剩余Cd2+质量浓度降至0.008 mg/L,Cd2+去除率为99.99%,处理后的废水达到GB8978—1996《污水综合排放标准》。  相似文献   

9.
用铝灰生产聚合氯化铝的工艺研究   总被引:1,自引:0,他引:1  
以铝灰、废盐酸为原料,用酸溶法(一步法)生产液体聚合氯化铝,对投料比、反应温度、反应时间、搅拌速度、熟化温度、熟化时间等参数对产品性能的影响进行了试验,得到了最佳生产工艺条件,并对产品的净水效果进行了模拟试验,净水效果明显。  相似文献   

10.
新型无机复合混凝剂的制备及脱色效果研究   总被引:9,自引:0,他引:9  
了以铝厂赤泥为原料制备无机复合凝凝剂的工艺,以制备过程中酸溶尼所用的盐酸浓度、酸溶时间和聚合PH等进行了优化。直接耐酸大红溶液和分散黄溶液的脱色以试验结果表明,此种混凝剂的脱色效果优于聚合氯化铝和聚合硫酸铁。  相似文献   

11.
湿法烟气脱硫系统的吸收塔设备   总被引:6,自引:0,他引:6  
介绍了石灰/石灰石-石膏湿法烟气脱硫系统中的关键设备吸收塔,其主要作用是以低成本和高可靠性提供吸收SO2的液体表面积,石灰/石灰石吸收剂在此与SO2反应达到脱硫的目的。  相似文献   

12.
Vitrification is an attractive approach for treatment of the borate waste from nuclear power plants. SL-1 glass is a suitable borosilicate glass form to solidify the borate waste containing relatively high quantities of B and Na. The leaching behavior of SL-1 glass in deionized water has been investigated. Compared to the HLW-glass, the network structure of SL-1 glass is weak. It was found that the ion-exchange reactions dominated the glass corrosion process with water in low temperature leaching conditions (⩽70°C). The ion-exchange and network hydrolysis reactions together controlled the glass dissolution in high temperature leaching conditions (>70°C). There was a peak in leach rate at about 70°C and a valley at about 110°C. The surface layer thickness was about 25 μm (MCC-1, 90°C for 28 days in deionized water). Na was almost totally depleted in the surface layer. At low temperature, the glass corrosion increases with leaching time. The glass corrosion remains about constant with leaching time at 90°C. The surface layer formed at 90°C is protective, which is less porous than the surface layer formed at 40 and 70°C.  相似文献   

13.
This paper discusses processes and factors for estimating time period windows of in situ burning of spilled oil at sea. Time-periods of in situ burning of Alaska North Slope (ANS) crude oil are estimated using available data. Three crucial steps are identified. The First Step is to determine the time it takes for the evaporative loss to reach the known or established limitation for evaporation and compare this time-period with estimated time of ignition at the ambient wind and sea temperatures. The Second Step is to determine the water up-take of the spilled oil and compare it with the known or established limitation for water-in-oil content. The Third Step is to determine the necessary heat load from the igniter to bring the surface temperature of the spilled oil to its flash point temperature so that it will burn at the estimated time period for ignition of the slick.  相似文献   

14.
Six film samples of low-density polypropylene (LDPE)/linear LDPE (LLDPE)/high-density polypropylene (HDPE) with varying ratios of LDPE (20–45 ... wt%) and LLDPE (25–50 wt%) having a fixed amount of HDPE at 30 wt% were prepared by blown film extrusion technique. The samples were aged at four different temperatures, 55°, 70°, 85°, and 100°C, for four different time periods in the interval of between 150 hours and up to 600 hours. The change in the structure of various constituents and the formation of various oxygenated (peroxy and hydroperoxy) and unsaturated groups during thermo-oxidative degradation was discussed by infrared spectroscopy. The visiosity-average molecular weight was found to have decreased slowly in the initial aging hours and temperatures, whereas it decreased by 10% with its previous value tensile strength that is, 100°C when aged for 600 hours. The tensile strength of the sample first increased by 67% at 55°C and 89% at 70°C up to 450 hours, whereas the values increased by 52.5% at 85°C and 33.9% at 100°C when aged for 150 hours and then decreased. The percentage elongation at break increased by 2.7% at 55°C and 10.7% at 70°C for 150 and 300 hours of aging, respectively, whereas the percentage decreased when aged at 85°C and 100°C for up to 600 hours of aging. The values of gel content (percent) increased and initial degradation temperature decreased with aging time and temperature.  相似文献   

15.
Cleaner technology and recycling, as the preferred solution to waste management, is increasing in implementation but not at the rate expected given the successes and paybacks associated with those strategies. The reasons for the delay in implementation lie in the conflict between short-term and long-term solutions. The factors that contribute to hindrance or facilitation of the transition are found in: a) the distinction between the short-term and the long-term at a technical level; b) the distinction between the short-term and the long-term at a political level; c) the investment decision at the firm level; and d) related investments in infrastructure, organization, and institutions. This article identifies which constraints will disappear with time, which constraints are institutional and will require deliberate modification, and which constraints are permanent and must be considered part of the costs of the long-term solution. The goal is not to argue against short-term solutions, but for the need to acknowledge unavoidable costs associated with the transition from the short-term to the long-term solution.  相似文献   

16.
Management of dredge material in the Republic of Ireland - A review   总被引:1,自引:0,他引:1  
As an island nation the Republic of Ireland's ports and harbours are key to the economic wellbeing of the country as they are the primary transport link to the United Kingdom, mainland Europe and beyond. This paper examines the main aspects of the Irish dredging industry with comparison to international practice and standards, including the source of the dredge material and volumes generated annually, the dredging plant employed and the management processes currently practised. Relevant European and Irish legislation governing dredging, disposal at sea and waste licensing are presented. The potential impacts of disposal at sea are discussed with the implications for the Irish dredging industry of recently introduced European Directives assessed. Beneficial use rates for dredge material and the techniques implemented in Ireland are examined and compared with international practice. Recent notable beneficial use projects for dredge material and proposed innovative dredge material management techniques for specific dredging projects in Ireland are presented. Proposals to encourage greater beneficial use of dredge material and minimise disposal at sea for Ireland are presented including the introduction of environmental credits, tax breaks and a grant system for pilot schemes. An alternative disposal at sea charge fee structure is also recommended to encourage alternative dredge material management practices. Ireland's management of contaminated sediment is also presented with recent projects described highlighting the current practice of primarily exporting contaminated sediment to mainland Europe. Alternative methods of treatment of contaminated sediment are assessed in an Irish context. Future issues and challenges facing the Irish dredging industry are assessed and a critical analysis of the current approaches to dredge material management is presented.  相似文献   

17.
蔡炜  尚希婷  王虎  江晓明  钟秦 《化工环保》2012,40(2):154-161
采用一步水热法合成了具有核壳结构的铬铈复合氧化物(Cr/CeO2),并将其用于选择性催化氧化(SCO)烟气脱硝,考察了前驱体溶液pH对催化剂低温催化活性的影响。实验结果表明,当前驱体溶液pH为2时制得的催化剂(CrCe2)具有较高的低温SCO活性,其在200 ℃下的NO转化率高达59%。XRD,SEM,BET,UV-Vis,TPD等表征结果显示:核壳结构的生成促进了Cr物种的高分散性,同时Cr的掺杂增大了催化剂的比表面积,从而提高了活性位点的总量;在该系列催化剂中,CrCe2催化剂具有最高的表面六价铬和化学吸附氧的占比,因此呈现出最高的低温SCO活性。  相似文献   

18.
Using organoclays to enhance carbon filtration   总被引:3,自引:0,他引:3  
Organoclays have found increased acceptance as pre-treatment for activated carbon adsorption systems in both groundwater and wastewater cleanup. The reason is that activated carbon tends to become quickly blinded by large organic molecules of low solubility, particularly oils. However, it is also well established that activated carbon is more efficient at low concentrations of organic contaminants than at higher ones, i.e. at less than 1 ppm. With organoclays it is exactly the opposite, they are better at removing organics at higher concentrations, above 3 ppm. Therefore it is cost effective in these applications to use two or more vessels in series, the first one filled with organoclay, the remainder with activated carbon. The economics make sense, even though the organoclay is not regenerated, because of the reduction in down time every time a carbon vessel has to be changed out. Use of organoclays increases the volume treated by carbon in many applications seven to nine fold. In the case of other organic contaminants, as the aqueous solubility increases, the efficiency decreases, except in the case of methylene chloride, which it removes at far higher efficiency then carbon. This article presents the results of a series of tests, including Kd determinations, jar tests, and mini-column tests. These tests determined the adsorption capacity and efficiency of organoclay and activated carbon for the removal of benzene, toluene, xylene and naphtalene from water. These tests were followed by adding the four compounds into one container to see if the combination of organoclay, followed by carbon, would be more efficient then each sorbent alone. The tests also compared the efficiency of organoclay versus carbon for the removal of various oils from water.  相似文献   

19.
In Japan the volume of municipal solid waste is reduced by incineration, with fly ash and bottom ash disposed in controlled landfills. The leachability of anions and heavy metal cations, Zn, Cu and Pb, from MSW fly ash and bottom ash at different pHs was examined using batch- and column-leaching tests. The MSW ashes had a high capacity for neutralizing acids. Behaviour during leaching depended on the pH of the solution. For the volumes applied, the leachabilities of MSW fly ash were very similar at pHs from 3 to 6. Due to its amphoteric nature, Pb is leachable at pHs of approximately 10 or more, with leachate concentrations of about 3 and 3-10mg/L for the fly ash and bottom ash, respectively, much higher than for Zn and Cu. Pb concentrations for most leaching solutions were 1 and 3mg/L for the fly ash and bottom ash, respectively. Zn, and Cu leached at low concentrations for solutions of pH 3-6. Na and K ions leached at high concentrations of approximately 5000 mg/L in the first batch leaching test, decreasing to 10mg/L by the fourth leach. Ca and Mg ions leached more gradually than Na and K. Cl(-) and SO(4)(2+) ions were the major anions in the MSW ash. The high pH and cation leaching are expected to have negative impacts on the performance of clay liners.  相似文献   

20.
The results from measuring PAH and metal contamination together with macroinvertebrate communities at 62 headwater stream sites gives a significant insight into the range and scale of contamination. Monitoring streambed sediments at 62 sites from rural to inner city and in industrial locations presented a unique opportunity to distinguish the conditions that enhance pollution runoff at sites that are less obviously `at risk' and to compare these results with sites of expected high contamination, for example in industrial areas and at motorway junctions. We used pCCA (partial Canonical Correspondence Analysis) to tease out the relationships between individual macroinvertebrate families and specific metal and PAH contaminants, and showed that it is not always the metals and PAHs with the greatest total concentrations that are doing the damage to the ecology. Ni and Zn are the critical metals, while benzo(b)fluoranthene, anthracene and fluoranthene are the most contaminating PAHs. The results identify previously unrecognized `high risk' pollution sources, lay byes used for commercial parking, on-street residential parking areas, and the junctions at the bottom of hills with traffic lights, where surface runoff feeds rapidly to the streams. While this study looks at sites across Yorkshire, UK, it clearly has a broader significance for understanding contamination risks from diffuse runoff as a prerequisite for effective sustainable urban drainage system (SUDS) agendas and the protection of urban stream ecology.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号