改性铁矾土深度处理含砷废水试验研究

以天然铁矾土制备得到改性铁矾土除砷吸附剂,以某铅锌冶炼企业含砷废水为研究对象,考察进水pH、砷浓度、滤速等因素对砷去除率的影响,并考察了吸附剂再生后的吸附效果。结果表明,化学改性处理后,铁矾土对废水中砷的动态吸附容量明显提高,处理后废水中的残余砷浓度低于《铅、锌工业污染物排放标准》(GB 25466—2010)中砷排放浓度限值。用质量分数为5%的Na OH溶液对饱和改性铁矾土进行再生,能有效恢复其砷吸附容量。     

改性粉煤灰吸附低浓度含砷含氨氮废水的机理研究

在有色金属冶炼、矿山采矿等行业里,排放废水中的砷和氨氮均存在不同程度的超标。本实验采用改性粉煤灰对低浓度砷和氨氮废水进行吸附处理。考察了溶液p H值、反应时间对改性粉煤灰除砷和氨氮的处理效果。实验结果表明:改性粉煤灰对两种污染物都有较好的去除效果。改性粉煤灰对氨氮的吸附符合Langmuir吸附等温线模型,对砷的吸附符合Freundlich吸附等温线模型;且均符合准二级动力学。其吸附去除机理是由于三价铁离子与砷发生反应形成难溶的化合物;氨氮的去除主要是由于改性粉煤灰表面的离子交换作用。     

胶原纤维负载锆处理高浓度砷(Ⅴ)氟废水的研究

将胶原纤维负载锆(ZrCF)用于高浓度砷(Ⅴ)、氟废水的处理。研究了ZrCF对砷(Ⅴ)、氟共存溶液的吸附,并以化肥厂高浓度砷(Ⅴ)氟废水为例,考察了吸附剂用量、pH、接触时间对吸附性能的影响,进行了固定床吸附实验。结果表明,相同浓度下ZrCF对砷(Ⅴ)的亲和作用优于对氟离子(F)的作用;吸附剂用量超过0.8 g,化肥厂出水的砷(Ⅴ)、氟浓度同时达到排放标准;处理的最佳酸度值是pH=6.0,满足出水浓度限值的反应时间为6 h;流出液体积为4.68 L时,固定床对氟、砷(Ⅴ)均达到饱和。ZrCF可以高效地联合去除废水中的砷(Ⅴ)和氟。     

改性活性炭铁吸附剂处理含铬电镀废水

通过采用锰盐对普通颗粒活性炭进行改性,添加少量铁屑后,获得了对电镀废水中重金属铬具有更强吸附能力的改性活性炭铁吸附剂。该吸附剂具有吸附速度更快、吸附量更大以及适应p H范围更宽的特点。对低浓度含铬废水,改性活性炭铁吸附剂能在p H为6~7、接触时间为1.5 h实现90%以上的总铬去除率。     

即时合成铜镁铝水滑石处理红青莲染料废水的研究

研究了铜镁铝水滑石(HTLCs)及煅烧500℃条件下的HTLCs-500对红青莲染料废水溶液的吸附性能。考察了吸附剂投加量、反应时间、初始p H值、反应温度对二者吸附红青莲染料废水的影响。利用正交实验确定了HTLCs及HTLCs-500对红青莲染料废水的最佳吸附条件。实验结果表明,最佳吸附条件下,HTLCs及HTLCs-500对300 mg/L红青莲染料废水脱色率分别达到为92.73%和97.52%,且在较宽的p H值范围内二者的脱色性能稳定,HTLCs-500对该染料的吸附效果优于HTLCs。     

以Mg-Al-LDHs为吸附剂脱除海水淡化产品水中硼的研究

考察了以Mg-Al-LDHs为吸附剂脱硼过程中,各条件对产物脱硼效率的影响,考察的因素包括:吸附剂用量、硼溶液浓度、p H、吸附反应时间、温度、阴离子和阳离子杂质等。结果表明,吸附剂对硼的饱和吸附量为35 mg/g;90%硼的吸附发生在反应的前2 h内;Langmuir吸附等温式能较好地描述硼的吸附过程;p H在8~10的范围内,吸附量均较大。p H在小于8时,单位吸附量随p H的变化量很小;p H大于8时,随p H的增大,吸附量降低。将Mg-Al-LDHs吸附剂应用于海水淡化产品水的脱硼,脱硼率可达到85%。     

煤矸石复合吸附剂对含铅废水处理性能研究

以煤矸石、石灰石和氯化铝为原料,制备呈碱性的复合吸附剂和呈中性的复合吸附剂,处理含铅(Ⅱ)废水,结果表明,碱性吸附剂的最佳吸附条件为投加量0.5 g,吸附时间60 min,p H为1,反应温度为25℃时,此时吸附量为7.62 mg/g,去除率为96.68%;中性吸附剂的最佳吸附条件为投加量0.5 g,吸附时间80 min,p H为1,反应温度25℃,此时吸附量达到7.19 mg/g,去除率为85.40%。碱性复合吸附剂吸附含铅(Ⅱ)废水能较好的与准二级动力学拟合,中性复合吸附剂吸附含铅(Ⅱ)废水能较好的与准一级动力学拟合。采用Freundlich方程描述碱性复合吸附剂吸附低浓度和高浓度含铅(Ⅱ)废水,用Langmuir方程描述中性吸附剂吸附低浓度含铅(Ⅱ)废水,用Temkin方程描述中性吸附剂吸附高浓度含铅(Ⅱ)废水。     

煤矸石复合吸附剂对含铅废水处理性能研究

以煤矸石、石灰石和氯化铝为原料,制备呈碱性的复合吸附剂和呈中性的复合吸附剂,处理含铅(Ⅱ)废水,结果表明,碱性吸附剂的最佳吸附条件为投加量0.5 g,吸附时间60 min,p H为1,反应温度为25℃时,此时吸附量为7.62 mg/g,去除率为96.68%;中性吸附剂的最佳吸附条件为投加量0.5 g,吸附时间80 min,p H为1,反应温度25℃,此时吸附量达到7.19 mg/g,去除率为85.40%。碱性复合吸附剂吸附含铅(Ⅱ)废水能较好的与准二级动力学拟合,中性复合吸附剂吸附含铅(Ⅱ)废水能较好的与准一级动力学拟合。采用Freundlich方程描述碱性复合吸附剂吸附低浓度和高浓度含铅(Ⅱ)废水,用Langmuir方程描述中性吸附剂吸附低浓度含铅(Ⅱ)废水,用Temkin方程描述中性吸附剂吸附高浓度含铅(Ⅱ)废水。     

改性柚子皮对含汞废水吸附性能研究

文中以废弃的柚子皮为原料,研究经Zn Cl2改性后的柚子皮对废水中汞的去除率以及吸附剂的加入量、p H、时间、温度以及吸附剂的粒径大小对废水汞去除率的影响。实验结果表明,适宜吸附条件为粒径大小80目,吸附时间90 min,吸附剂用量0.01 g/m L,p H为6。在该条件下改性柚子皮吸附法的终末废水中汞的含量为(0.1016±0.0035)mg/L,Hg2+的去除率达到89.85%。     

壳聚糖复合粉煤灰吸附处理含氮废水的实验研究

通过单因素实验和正交实验,对壳聚糖复合粉煤灰吸附处理含氮废水进行了实验研究,研究了吸附时间,吸附剂投加量,p H对氨氮去除率的影响趋势。结果显示三个因素对氨氮去除率影响大小为:吸附时间氨氮废水p H吸附剂投加量。最佳处理条件确定为吸附时间60min,投加量3 g,p H为9,此时氨氮的去除率为12.02%。     

聚丙烯酸钠吸附含铜废水的研究

用聚丙烯酸钠吸附含铜废水,考察了吸附剂用量、时间、温度、pH值对聚丙烯酸钠吸附铜性能的影响。结果表明,对含200 mg/L的高铜废水,吸附条件为温度50℃,聚丙烯酸钠量30 g/L,时间60 min,pH为6时,聚丙烯酸钠对其的吸附率为97.14%,最大吸附容量为8.35 mg/g。聚丙烯酸钠对Cu2+的吸附具有Langmuir吸附特征,分子中的羧基与Cu2+发生了配位作用,吸附机理以单分子层化学吸附为主,吸附量受温度影响不大。     

超声对铁锰氧化物吸附废水中无机砷的强化效应

快速吸附去除废水中无机砷的技术,由于其高效性成为污水处理领域亟需的一种技术。采用草酸沉淀法制备了不同铁锰比（物质的量比）的铁锰复合草酸盐,以铁锰复合草酸盐为前驱体通过热分解得到铁锰元素均匀分布的复合氧化物,以铁锰复合氧化物为吸附剂吸附去除废水中的无机砷。在超声波辅助下,铁锰复合氧化物对废水中无机砷的去除效果显著。实验结果表明,铁锰物质的量比为6:4的铁锰复合氧化物,因具有较高的比表面积（396.6 m²/g）和独特的形貌,超声辅助1 min对废水中无机砷的吸附率可达95%以上。吸附动力学研究表明,该吸附过程符合准二级动力学模型,吸附速率常数为1.11 g/（mg·s）。吸附剂再生实验表明,将吸附砷的吸附剂采用碳酸氢钠溶液洗脱重复用于吸附实验,吸附剂重复使用3次对砷的吸附率仍可达到83.6%。     

膨胀石墨在低浓度含油废水处理中的应用

对吸附法用于含油废水深度处理中存在吸附剂吸附容量低的问题展开研究。通过对比多种吸附材料对低浓度含油废水的处理效果发现,改性鳞片石墨的处理效果最佳。文章考察了pH、温度、含盐量及流速等因素对膨胀石墨处理低浓度含油废水的影响。研究表明:30℃、流速在80BV/h时,1BV膨胀石墨下可处理2570BV的废水,出水油质量浓度9mg/L。     

Single and competitive adsorption affinity of heavy metals toward peanut shell-derived biochar and its mechanisms in aqueous systems

Converting peanut shells into biochar by pyrolysis was considered an environmentally friendly and efficient method for agricultural solid waste disposal. The properties of peanut shell-derived biochar (PBC) under different temperature and its adsorption capacity of heavy metals were investigated. It was found that PBC400 exhibited the highest cumulative capability for heavy metals elimination in single solute because of its high specific surface area and rich functional groups. Furthermore, the competitive adsorption revealed that PBC had a substantial difference in adsorption affinity from diverse heavy metal ions, sorption capacity decreased as Pb²⁺ > Cu²⁺ > Cd²⁺ > Ni²⁺ > Zn²⁺, which was lower than in a single solute. The adsorption process using selected biochar was optimized with respect to pH, reaction time, adsorbent dose, and initial concentration of heavy metals. The kinetic data was well fitted with PSO model, and the Langmuir model was adopted for adsorption equilibrium data in both cases of single solutes and mixed solutes for all heavy metals, which indicated that the removal course was primarily explained by monolayer adsorption, and chemical adsorption occupied an important role. Therefore, peanut shells derived biochar could be a potential and green adsorbent for wastewater treatment.     

Arsenic adsorption using copper (II) oxide nanoparticles

Arsenic poisoning is a major problem in today's life. To reduce its concentration in drinking water, different metal based compounds were explored as arsenic adsorbents. In the present study, copper (II) oxide nanoparticles were prepared by thermal refluxing technique and used as an adsorbent for arsenic removal from water. Characterization of the adsorbent using TEM, BET, XRD and FTIR implied that the prepared adsorbent was in nano size and had excellent adsorption behavior with surface area of 52.11 m²/g. Systematic adsorption experiments were carried out with different process parameters such as contact time, adsorbent mass, pH, temperature and stirring speed and found that copper (II) oxide had very good efficiency towards arsenic adsorption. Thermodynamic parameters and adsorption kinetics were studied in detailed to know the nature and mechanism of adsorption. Results showed that the adsorption process followed pseudo second order kinetic and endothermic behavior. Adsorption equilibrium was studied with Langmuir and Freundlich isotherm models. The adsorption process followed Langmuir isotherm with an adsorption capacity of 1086.2 μg/g. A regeneration study was proposed in order to reuse the adsorbent for better economy of the process. Finally, a process design calculation is reported to know the amount of adsorbent required for efficient removal of arsenic from aqueous medium.     

活性炭吸附处理含酚废水的研究进展

含酚废水对环境和生物有较大危害,是一种常见的化工废水。活性炭作为良好的吸附剂被广泛用于污水处理,也常被用于吸附处理含酚废水。最新的研究集中于开发利用各种含碳原材料,并探究活性炭制备和改性方法,以改善活性炭对酚类的吸附性能。部分机理研究则关注活性炭的孔隙结构和表面官能团及其对吸附酚类性能的影响。本文从活性炭的制备和改性出发,归纳整理活性炭吸附酚类的特性和机理,分析吸附过程的主要影响因素,并对研究发展方向进行推论和展望。分析表明含碳量高的原材料适合制备活性炭,尤其是含碳废弃物。活性炭的苯酚吸附性能受比表面积和表面官能团的共同影响,这对于活性炭的制备和改性有指导意义。活性炭吸附苯酚的具体应用中,需要控制粒度、pH、温度、吸附时间和竞争吸附等影响因素。     

Fe3O4@SA/CTS凝胶球对亚甲基蓝及碱性品红的吸附

为解决染料对水体污染问题,本工作以海藻酸钠为骨架,结合Fe3O4及壳聚糖,制备了Fe3O4@SA/CTS凝胶球,并对制备的材料进行了微观表征。研究了不同影响因素下,吸附剂对MB及CB的吸附效果,同时研究了不同pH下对混合液的吸附性能,以及吸附剂循环利用性实验。结果表明,MB或CB初始浓度为100 mg/L、吸附剂投加量为1.0 g/L、MB的pH为11或CB的pH为8、反应时间4 h、MB和CB的去除率分别可以达到91.9%和21.5%。Langmuir模型能够更好反应对MB或CB的吸附,吸附以单分子物理吸附为主。吸附动力学符合伪二级动力学方程,吸附过程更容易受到化学吸附影响。不同pH下,Fe3O4@SA/CTS对混合液中的MB吸附优于CB,5次脱附循环使用后对MB保持在70%以上,对CB的去除率保持在15%以上。     

Low cost adsorbents obtained from ash for copper removal

We investigated the utilization of ash and modified ash as a low-cost adsorbent to remove copper ions from aqueous solutions such as wastewater. Batch experiments were conducted to determine the factors affecting adsorption of copper. The influence of pH, adsorbent dose, initial Cu²⁺ concentration, type of adsorbent and contact time on the adsorption capacity of Cu²⁺ from aqueous solution by the batch adsorption technique using ash and modified ash as a low-cost adsorbent were investigated. The optimum pH required for maximum adsorption was found to be 5. The results from the sorption process showed that the maximum adsorption rate was obtained at 300 mg/L when a different dosage of fly ash was added into the solution, and it can be concluded that decreasing the initial concentration of copper ion is beneficial to the adsorption capacity of the adsorbent. With the increase of pH value, the removal rate increased. When the pH was 5, the removal rate reached the maximum of over 99%. When initial copper content was 300 mg/L and the pH value was 5, the adsorption capacity of the zeolite Z 4 sample reached 27.904 mg/g. The main removal mechanisms were assumed to be the adsorption at the surface of the fly ash together with the precipitation from the solution. The adsorption equilibrium was achieved at pH 5 between 1 and 4 hours in function of type of adsorbent. A dose of 1: 25 g/mL of adsorbent was sufficient for the optimum removal of copper ions. For all synthesized adsorbents the predominant mechanism can be described by pseudo-second order kinetics.