共查询到18条相似文献,搜索用时 203 毫秒
1.
为了实现固废资源化利用,以废弃荞麦壳为原料采用化学活化法制备了一种新型吸附 剂———荞麦壳基活性炭。 采用单因素方法对制备过程中的活化温度、活化时间、活化剂种类和荞 麦壳与活化剂的质量比进行了优化,通过碘值和亚甲蓝值考察了优化后荞麦壳基活性炭的吸附 效能,并采用气体吸附仪、X射线衍射法和扫描电镜分析表征了活性炭的孔结构、微晶结构及微 观表面形貌。 结果表明:当采用磷酸活化剂、活化时间90min、活化温度500℃、荞麦壳与活化剂 的质量比为1∶3时,获得的荞麦壳基活性炭碘值和亚甲蓝值分别为765.8mg/g和222.2mg/g, 其亚甲蓝值高于市售的三种活性炭(煤基、木质、椰壳活性炭);同时,优化后的荞麦壳基活性炭 的中孔孔隙率最大为96.8% ,总孔容量(0.666cm3/g)高于煤基活性炭和椰壳活性炭,比表面积 (785.3m2/g)与市售活性炭相当,说明以荞麦壳为原料采用磷酸活化可制备出中孔发达、吸附性 能好的活性炭。 相似文献
2.
3.
4.
5.
6.
为解决变压吸附法提纯煤层气中甲烷遇到的吸附剂难题,以我国海南产椰壳炭化料为原料,采用二次炭化-水蒸气物理活化工艺制备生物质基活性炭,采用高压电子天平测量了298 K、0~1. 0 MPa下CH_4/N_2在制备得椰壳活性炭上的吸附等温线,利用比表面积和孔径吸附仪测量了活性炭的孔径结构,详细研究了活化工艺参数对CH_4/N_2吸附分离性能及孔隙结构的影响。通过变压吸附装置检验了最佳工艺参数条件下制备椰壳活性炭的CH_4提浓效果。研究结果表明,随着活化温度的提高,平衡分离系数逐步减小,吸附容量逐步增加,最佳活化温度为850℃;平衡分离系数和饱和吸附容量均随水蒸气流量的增加呈先增加后减小的趋势,最佳水蒸气流量为2.0 kg/h;平衡分离系数随活化时间延长先增加后减小,甲烷饱和吸附容量逐渐递增,最佳活化时间为40 min。升高活化温度对孔结构的发育影响显著,比表面积、微孔孔容和总孔容均呈递增趋势,表明升高温度有利于微孔的发育,可制备出微孔发达的活性炭。变压吸附评价结果表明在水蒸汽活化工艺最优条件下制备得椰壳活性炭可将20%CH_4-80%N_2模拟煤层气中的CH_4体积分数提高到48. 3%,提浓幅度大于25%,回收率为80.58%,产能达到108.82 m~3/(t·h);同时,该吸附剂对中高浓度煤层气也具有较好的分离效果,体现出较好的分离性能。 相似文献
7.
8.
以活性炭和偏高岭土为原料、水玻璃和氢氧化钠为激发剂, 采用悬浮固化法制备了活性炭/地质聚合物复合微球(GMC)吸附剂, 通过X射线衍射仪、扫描电镜和紫外-可见分光光度计研究了其微观结构以及对刚果红(CR)和结晶紫(CV)的吸附性能。结果表明, GMC的吸附性能随活性炭添加量增加而提高, 活性炭添加量为30%时, 其对CR和CV的吸附过程符合Langmuir吸附模型和准二级动力学模型, 理论最大吸附量分别为61.88 mg/g和104.06 mg/g, 循环再生使用5次后对CR和CV的去除率依然可达71.73%和75.65%。 相似文献
9.
10.
11.
高锰酸钾改性对颗粒活性炭吸附Cu2+的影响 总被引:5,自引:1,他引:4
采用KMnO4溶液在回流状态下对颗粒活性炭进行了改性。考察了KMnO4 溶液浓度对Cu2+吸附率-pH曲线及pH的影响,并研究了KMnO4 改性对颗粒活性炭吸附和解吸Cu2+性能的影响。结果表明,KMnO4 改性使颗粒活性炭对 Cu2+吸附率-pH曲线及pH向低pH偏移。当KMnO4溶液浓度为0.03 mol/L时,改性颗粒活性炭效果最好;KMnO4 改性提高了颗粒活性炭对Cu2+的吸附速率,使其投加量节省约3倍;Cu2+在改性及未改性活性炭上的吸附遵循Freundlich等温吸附方程,在相同Cu2+平衡浓度下,KMnO4改性活性炭对 Cu2+的吸附量提高约 2.7倍;使用 0.35 mol/L的HCl溶液作解吸液,Cu2+从KMnO4改性活性炭上的解吸率为 91.1%,而Cu2+从未改性活性炭上的解吸率仅为8.8%。KMnO4 改性提高了颗粒活性炭从水中吸附重金属离子的能力,并促进了其解吸再生性能。 相似文献
12.
提出将粉煤灰空心微珠作为吸附剂应用于铅锌选矿废水治理。首先采用BET、SEM、XRD、Zeta电位等测试方法,考察了微珠的弱酸活化机制,然后对实际废水中残留的选矿药剂以及重金属离子开展了吸附试验研究。结果表明:微珠经弱酸活化后,其表面电位由-1.797 6mV增加到-15.538 7mV,大幅度提高了静电吸附能力;对实际废水中的COD有很好的去除效果,但四种药剂呈现不同的吸附行为。饱和吸附量方面:腐植酸钠(6.492mg/g)乙硫氮(2.250mg/g)丁基黄药(1.680mg/g)BK-906(0.024mg/g);吸附速率方面:腐植酸钠(K=0.330 2min~(-1))丁基黄药(K=0.312 1min~(-1))BK-906(K=0.020 1min~(-1))乙硫氮(K=0.008 1min~(-1))。对废水中低浓度的Zn~(2+)、Pb~(2+)、Cu~(2+)离子也呈现出一定的去除效果,重金属离子与残留的选矿药剂的络合共吸附是其主要去除机理。 相似文献
13.
使用高精密质量吸附仪IGA-100B对可用的吸附剂进行吸附分离实验。选取椰壳活性炭K01,测定了CH4、N2、CO2在其上于298、308、323 K温度下的吸附等温线和吸附动力学曲线,由此分析了3种气体的吸附性能、热力学及动力学扩散性质,从而得到不同温度下CH4、N2、CO2之间的平衡分离系数(α)和扩散系数(D)之比。结果表明,椰壳活性炭K01可以实现不同温度下CH4/N2、CO2/N2的平衡分离;两种气体的动力学分离与压力和温度有关,在298 K压力较低时,可能实现N2与CH4的动力学分离;而在298 K和323 K时,在较宽的压力范围内,可能实现N2和CO2的动力学分离。 相似文献
14.
《Minerals Engineering》2006,19(9):918-924
The present work describes studies concerning a new adsorption technique based on the use of adsorbent flocs in an expanded/fluidised bed reactor for the removal of pollutants from aqueous solutions. The technique, based on flocculation of aqueous suspensions of powdered adsorbent materials, when conducted in an expanded/fluidised bed reactor takes advantage of conducting adsorption and solid–liquid separation in one single stage. Studies were performed using flocculated powdered activated carbon and natural zeolites, alone and in mixtures, for phenol and ammonia adsorption. A reactor with cylindrical–conical geometry was used for the pollutants adsorption in flocs beds (pure and mixed), as well as the regeneration/recycle of the exhausted adsorbents. Results proved the high adsorption efficiency of powdered natural zeolites and activated carbon flocs for the uptake of ammonia (11 mg NH3–N g−1) and phenol (132 mg g−1), at 38 and 19 m h−1 loading rates, respectively. Regeneration/recycle of the pollutant-saturated beds was possible for the ammonia/natural zeolites adsorption case, using sodium sulphate as regenerator. Use of mixed flocs beds was efficient, showing advantages such as multiple-pollutants adsorption in one single stage, higher loading rates when using light materials (activated carbon) combined with heavier ones (natural zeolites) and use of small adsorbent concentrations (not possible otherwise). Economical and environmental issues regarding the technique are also discussed in the paper. The new technique shows great potential as an alternative physicochemical adsorption process for pollutant removal from aqueous solutions using low-cost and highly-available powdered adsorbent materials. 相似文献
15.
《Minerals Engineering》2003,16(5):421-427
Bagasse, the fibrous residue from sugar cane milling operation, was subjected to physical activation using CO2 to establish its suitability as a precursor for gold adsorption, specifically for the recovery of gold from cyanide medium. Mathematical modelling, which correlates the effects of carbon properties on the adsorption behaviour, was conducted to formulate a basis for tailor making the adsorbent for this particular application. The developed model suggests carbon properties of alkali pH, high total surface area and small pore diameters are required for optimum adsorption capacity. The optimum adsorption capacity attained by the developed carbon in this study was 227% that of the test commercial activated carbon, which exhibited an adsorption of 101mg Au/g carbon. Hence this demonstrates bagasse as a promising precursor for the manufacture of activated carbon for gold cyanide adsorption. 相似文献
16.
环境pH对腐植酸-重金属的结合稳定性有显著影响,采用不同pH解吸液对吸附Cd2+后的腐植酸(腐植酸-Cd)进行解吸规律研究。结果表明,煤基腐植酸(HA1和HA2)的官能团、腐殖化与芳构化程度是影响腐植酸-Cd稳定性的主要结构特征。HA1较HA2含氧官能团更多,Cd2+吸附量更高,HA1和HA2对Cd2+吸附量在Cd2+初始浓度 100mg/L时分别为905mg/g和582mg/g;|HA1-Cd和HA2-Cd在纯水解吸的保留率总体大于80%;pH=3解吸液中Cd2+保留率降低明显,HA2对Cd2+的保留作用更强|pH=5、7解吸液中随Cd2+初始浓度的增大HA1-Cd和HA2-Cd解吸规律一致,Cd2+初始浓度越高,三次解吸后保留率越大,均在60%左右|ζ电位分析表明,HA-Cd中Cd2+解离存在自发解离和离子交换两种途径,H+、Na+及醋酸根配体的共同作用导致结合不稳定的Cd2+再次释放。 相似文献
17.
The paper deals with a possible utilisation of wood ash as a reagent in treating acid mine drainage (AMD) from opencast mining of brown coal. Wood ash samples were obtained having combusted deciduous and coniferous tree wood in a household furnace. The dominant mineral phases in wood ash are calcite, quartz, lime and periclase. The used AMD is characteristic of high contents of sulphates, iron, manganese, heavy metals and low pH. The AMD treatment process included dosing of wood ash to adjust pH values about 8.3 (a dose of 0.5 g l−1) or calcium hydroxide (a dose of 0.2 g l−1) for comparison. The reaction time was 20 min. Dosing of wood ash in AMD resulted in an increase of pH in solution from 3.5 to 8.3, which caused the removal of metal ions mainly by precipitation, co-precipitation and adsorption. Comparing the application of Ca(OH)2 in AMD treatment, at an almost identical pH value the concentrations fell in both cases for Fe, Mn, As, Co, Cu, Ni, Zn, Mg, Al and Mo. Applying wood ash the drop was even more distinct in Mn, Zn and Mg. The results of sedimentation tests in an Imhoff cone confirm that the settling capacities of sludge using wood ash are significantly better than when using calcium hydroxide in acid mine drainage treatment. 相似文献