磷石膏对黄壤磷吸附性能及吸附动力学分析

研究了磷石膏（PG）对黄壤磷吸附能力的影响,并探讨其影响机制。以贵州省黄壤为研究对象,探索不同掺量的PG在不同培养时间等条件下对黄壤磷吸附性质的影响,并通过吸附动力学实验和数据模型拟合分析了PG对黄壤磷吸附动力学行为的影响。结果表明：PG掺量对黄壤磷吸附量影响显著（P<0.05）。磷吸附量随PG掺量增加呈先增加后降低趋势,掺量为0.5?g/100?g土时达最高值,与原土相比,磷吸附量提高2.80%,pH由3.77升至4.00,无定型氧化铁（Feo）含量上升2.33%;PG掺量分别为0.5?g/100?g土和1.0?g/100?g土的混合土样磷吸附动力学过程符合准一级方程,之后,随掺量增加混合土样磷吸附动力学过程符合准二级方程;磷石膏对黄壤磷吸附能力的影响在前7天最为显著,且磷石膏中Na2SO4、NaH2PO4和CaSO4对黄壤磷吸附能力起促进作用,NaF对黄壤磷吸附能力起抑制作用。     

改性石英砂过滤吸附去除微量磷

对涂铁改性石英砂滤料进行了过滤吸附去除微量磷试验研究。结果表明,改性石英砂对总磷的去除率迭90％以上。吸附试验获得的对溶解性总磷的吸附等温线属于Langmauir型,并得出涂铁改性石英砂的除磷吸附等温式。     

ATP颗粒吸附剂对磷的吸附性能

通过静态吸附实验,研究了ATP颗粒吸附剂对水体中磷的吸附性能,并从动力学和热力学角度探讨了吸附作用机理。结果表明,ATP颗粒吸附剂对磷的吸附符合准二级动力学方程,以化学吸附为速率控制步骤;表观吸附活化能Ea为5.883 kJ/mol,说明温度对该吸附过程影响较小;在288³08 K范围内,ATP颗粒吸附剂对磷的吸附符合Freundlich等温吸附方程,该吸附介于单层和多层吸附之间,吸附表面存在一定的不均匀性;由吸附过程的热力学参数ΔG为-4.964308 K范围内,ATP颗粒吸附剂对磷的吸附符合Freundlich等温吸附方程,该吸附介于单层和多层吸附之间,吸附表面存在一定的不均匀性;由吸附过程的热力学参数ΔG为-4.964^-5.403 kJ/mol、ΔS为0.107-5.403 kJ/mol、ΔS为0.107⁰.131 kJ/(mol·K)、ΔH为27.9850.131 kJ/(mol·K)、ΔH为27.985³3.498 kJ/mol,表明ATP颗粒吸附剂对磷的吸附属于自发的、熵增加的吸热过程,同时存在物理吸附和化学吸附。     

ATP颗粒吸附剂对磷的吸附性能

通过静态吸附实验,研究了ATP颗粒吸附剂对水体中磷的吸附性能,并从动力学和热力学角度探讨了吸附作用机理。结果表明,ATP颗粒吸附剂对磷的吸附符合准二级动力学方程,以化学吸附为速率控制步骤;表观吸附活化能Ea为5.883 kJ/mol,说明温度对该吸附过程影响较小;在288~308 K范围内,ATP颗粒吸附剂对磷的吸附符合Freundlich等温吸附方程,该吸附介于单层和多层吸附之间,吸附表面存在一定的不均匀性;由吸附过程的热力学参数ΔG为-4.964~-5.403 kJ/mol、ΔS为0.107~0.131 kJ/(mol·K)、ΔH为27.985~33.498 kJ/mol,表明ATP颗粒吸附剂对磷的吸附属于自发的、熵增加的吸热过程,同时存在物理吸附和化学吸附。     

壳聚糖吸附水溶液中磷的热力学和动力学机理的探讨

通过研究质子化壳聚糖对水溶液中H2PO4^-吸附的热力学和动力学行为,探讨其吸附机理,为优化壳聚糖处理水溶液中磷的工艺提供理论依据。利用在稀硫酸介质中,磷-铋-钼三元配合物可被抗坏血酸还原生成磷铋钼蓝,700nm处进行比色,测量浓度变化,研究吸附行为。实验结果表明,△H=-10．6594 kJ·mol^-1,△S=3．0329 J·mol^-1·K^-1,温度对壳聚糖吸附磷的影响,可用热力学公式表示：△G=-10．6594×10^3-3．0329T;吸附表观活化能Ea=141．828 kJ·mol^-1。壳聚糖对磷的吸附是放热反应,熵增加效应是驱使壳聚糖吸附磷的重要推动力。     

污泥生物炭制备及其对磷的吸附性能研究

以污水污泥、粉煤灰为原料,以质量分数为30%的氯化锌溶液为活化剂,在不同温度下煅烧制备污泥生物炭,用于处理含磷废水。通过单因素静态吸附实验探讨了污泥生物炭对磷的去除效果,并探究了其吸附机理。结果表明：300 ℃制备的污泥生物炭具有较好的除磷效果;扫描电镜（SEM）、比表面分析仪、傅里叶红外光谱仪（FT-IR）对原料和污泥生物炭表征结果显示,污泥生物炭煅烧前后的形貌及表面基团发生了显著改变,煅烧后样品的表面产生了较多微小空隙,比表面积增大,最高可达5.51 m²/g;在磷初始质量浓度为50 mg/L、吸附剂用量为16 g/L条件下,吸附在90 min达到平衡,磷的去除率高达93.73%;吸附过程符合准二级动力学方程及Freundlich等温吸附模型,最大饱和吸附量为9.615 mg/g;整个吸附过程ΔG⁰<0、ΔH⁰<0,是自发进行的放热过程;吸附过程除物理吸附外,同时涉及磷酸盐与吸附剂—OH或C—O共价键发生电子对配位作用,为物理-化学复合吸附;吸附剂第5次吸附为首次吸附量的85.74%,表现出较好的再生性能。     

给水污泥对水中磷的去除性能研究

以给水污泥为吸附剂,采用单因素实验,考察了多种因素对含磷废水中磷去除效果的影响.在磷初始浓度为50mg·L-1、吸附剂投加量20 g·L-1、pH值为4.5、吸附时间10h的条件下,磷去除率达93.15％.采用Lagergren一级动力学模型、伪二级动力学模型、颗粒内扩散模型、双常数模型,对吸附效果进行拟合分析.动力学...     

钢渣对废水中磷的吸附性能

通过批次振荡实验研究了钢渣吸附磷的特性.结果表明,钢渣对磷的吸附过程符合Langmuir和Freundlich方程,理论饱和吸附量为0.33g/kg,为优惠型吸附.吸附动力学过程符合Lagergren准二级动力学方程,平衡吸附量随温度升高而增加,吸附速率主控步骤为液膜扩散和颗粒内扩散同时存在.吸附热力学参数ΔH0,ΔG0,ΔS0,钢渣对磷的吸附为吸热、自发的物理吸附过程,升高温度有利于吸附进行.     

鸡蛋壳对磷的吸附特性研究

通过研究时间、温度、磷初始浓度、pH和灼烧温度等因素对磷在鸡蛋壳上吸附的影响.结果表明,鸡蛋壳在吸附的初始阶段(0～2h),吸附量上升很快,此后趋于平缓,鸡蛋壳对磷的动力学吸附过程很好地遵循准一级动力学模型;吸附热力学研究表明鸡蛋壳吸附磷过程中,系统的△G~0<0,△H~0>0,鸡蛋壳对磷的吸附作用是一个自发的吸热过程;鸡蛋壳对磷的等温吸附可采用Freundich等温模型拟合,相关性达到显著水平;鸡蛋壳在酸性条件下吸附量远远大于在碱性条件下的吸附量;随着灼烧温度升高,单位吸附量上升.     

凹凸棒石/氢氧化物纳米复合材料对磷的吸附热力学

用铁/铝盐水解法制备了凹凸棒石/铝氢氧化物(PNCM Ⅰ)、凹凸棒石,铁氢氧化物(PNCM Ⅱ)和凹凸棒石/铁-铝氢氧化物(PNCM Ⅲ)3种凹凸棒石黏土纳米复合材料,对比研究了这3种复合材料和纯凹凸棒石黏士对水中磷的吸附净化能力,通过等温吸附实验探讨了3种纳米复合材料对磷的吸附机理.结果表明:PNCM Ⅰ和PNCMⅢ凹凸棒石黏十纳米复合材料对磷具有良好的吸附净化能力,而且温度对其影响很小;当初始浓度为1,2mg/L和5mg/L(以磷计)时,100mL水中加入0.1 g的PNCMⅠ和PNCM Ⅲ对磷的去除率可达到99%以上,对磷的吸附容量分别约为8mg/g和15mg/g;这3种凹凸棒石复合材料吸附过程均属于Langmuir吸附;PNCMⅠ和PNCMⅢ对磷的吸附是吸热的化学吸附和物理吸附并存的过程,PNCMⅡ对磷的吸附是吸热的物理吸附过程,且都为熵增加的吸附过程.     

沙质滩涂颗粒物对磷酸盐的吸附过程研究

以沙质滩涂颗粒物对磷酸盐的吸附过程为对象,通过拟一级和拟二级方程进行吸附动力学研究,采用Langmuir和Freundlich方程描述平衡吸附等温线,并计算得到吸附热力学参数。结果表明:拟二级动力学模型能够较好拟合吸附过程,Langmuir模型能更好的描述吸附等温线,吸附是焓推动作用、自发且放热的过程。     

Removal of Pb(II) from Aqueous Solutions by using Chitosan Coated Zero Valent Iron Nanoparticles

This study reports the synthesis, characterization, and application of chitosan coated zero valent iron nanoparticles (CTS-Fe⁰) in the removal of Pb(II) from aqueous medium. This nano adsorbent showed a high adsorption capacity and efficient adsorption towards Pb(II) in aqueous medium. Adsorption of Pb(II) on CTS-Fe⁰ obeyed pseudo-second order kinetics and was controlled by a film diffusion process. Among the various isotherm models the experimental data followed the Langmuir isotherm and the maximum adsorption capacity was found to be 666.6 mg/g at pH 5.0 and 318 K. The sorption mean free energy from D-R isotherm was found to be 72, 131, and 177 J/mol at 298, 308, and 318 K, respectively, indicating a physical sorption. The percentage of Pb(II) removal by CTS-Fe⁰ particles is more than 90% at 318 K. The calculated thermodynamic parameters showed that the adsorption of Pb(II) is feasible, spontaneous, and endothermic in nature. Experimental results indicated that the CTS-Fe⁰ appears to be a promising adsorbent for the removal of Pb(II) from aqueous media.     

蜂巢石对水中正磷酸盐的吸附性能

该文研究了不同初始浓度、温度和振荡时间条件下蜂巢石矿物质对水中正磷酸盐的吸附行为。结果表明在蜂巢石投加量不变的情况下,蜂巢石对低浓度正磷酸盐有较强的吸附能力,平均吸附率达45％;蜂巢石对正磷酸盐的吸附在10min时达到最大吸附量,体现了快速吸附的特点;该反应是吸热反应,蜂巢石对正磷酸盐的去除率随着温度的升高而增加;正磷酸盐在蜂巢石中易于脱附,2h内的脱附量可达93％;蜂巢石对正磷酸盐的吸附行为符合Langmuir和Freundlich吸附等温式拟合,吼值和1／n值表现为优先吸附,且其吸附兼有物理吸附及化学吸附两种作用。     

Cyclic Sorption and Desorption of Cu(II) onto Coconut Shell and Iron Oxide Coated Sand

Sorption is a viable treatment technology for copper-rich gold mine tailings wastewater. For continuous application, the sorbent should be regenerated with an appropriate desorbent, and reused. In this study, the sequential sorption/desorption characteristics of Cu(II) on coconut shell (CS) and iron oxide coated sand (IOCS) were determined. In batch assays, CS was found to have a Cu(II) uptake capacity of 0.46 mg g^?1 and yielded a 93% removal efficiency, while the IOCS had a Cu(II) uptake capacity and removal efficiency of 0.49 mg g^?1 and 98%, respectively. Desorption experiments indicated that HCl (0.05 M) was an efficient desorbent for the recovery of Cu(II) from CS, with an average desorption efficiency of 96% (sustained for eight sorption and desorption cycles). HCl (0.05 M) did not diminish the CS's ability to sorb copper even after eight sorption/desorption cycles, but completely deteriorated the iron oxide structure of the IOCS within six cycles. This study showed that CS and IOCS are both good sorbents for Cu(II); but cyclical sorption/desorption using 0.05 M HCl is only feasible with CS.     

Adsorption Thermodynamic and Kinetic Studies of Fluoride Aqueous Solution Treated with Waste Iron Oxide

This study uses a waste iron oxide material (BT3), which is a by-product of the fluidized-bed Fenton reaction (FBR–Fenton), for the treatment of a fluoride (F^?) solution. The purpose of this study is to investigate a low-cost sorbent as a replacement for the current costly methods of removing fluoride from wastewater. X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) are used to characterize the BT3. Contact time, F^? concentration (from 0.75 to 6 mmol L^?1), and temperature (from 303 to 323 K) are used as operation parameters to treat the fluoride. The highest F^? adsorption capacity of the BT3 adsorbent was determined to be 1.17 mmol g^?1 (22.2 mg g^?1) for a 6 mmol L^?1 initial F^? concentration at pH 3.9 ± 0.2 and 303 ± 1 K. Adsorption data were well described by the Langmuir model, and the thermodynamic constants of the adsorption process, ΔG°, ΔH°, and ΔS°, were evaluated as ?1.63 kJ mol^?1 (at 303 K), ?1.75 kJ mol^?1, and ?52.4 J mol^?1 K^?1, respectively. Additionally, a pseudo-second-order rate model was adopted to describe the kinetics of adsorption. BT3 could be regenerated with NaOH, and the regeneration efficiency reached 95.1% when the concentration of NaOH was 0.05 mol L^?1.     

铁钛改性白云石吸附除磷的性能研究

对天然白云石进行钛、铁改性,分析化学成分、表面性能的变化,并用于对磷酸盐的吸附.结果表明,改性后的白云石的结构没有明显改变,但表面粗糙缺陷增加,比表面积增大,可以提供更多的吸附点位.钛改性白云石投加量为10g/L时,理论磷饱和吸附量为5.45mg/g.铁改性白云石投加量为5 g/L的理论磷饱和吸附量为7.36 mg/g...     

氧化钠对铁磷酸盐玻璃微结构影响的振动光谱分析

为探究铁磷酸盐玻璃对含钠核废物的包容特性,了解Na2O对其微结构的影响.采用熔融-冷却法制备xNaO-(100-x)(40Fe2O3-60P2O5)(0≤x≤50mol％)系列玻璃样品.利用XRD、Raman和FT-IR等手段对玻璃微观网络结构进行表征,对振动光谱的谱带归属进行了指认.结果表明:所有样品均为均质玻璃,铁磷酸盐基础玻璃结构以Q1结构单元为主,伴随Na2O含量的增加,Q1结构单元逐渐减少,Q0结构单元数量逐渐增加,同时形成了P-O-Na+离子键.在Na2O含量40mol％时,Q1结构单元特征谱峰消失.Na2O的引入,引起磷酸盐网络中非桥氧键增加桥氧键减少,导致磷酸盐玻璃结构解聚,微观网络结构松弛.     

磷酸锌/云铁灰环氧涂层防腐性能的研究

选用磷酸锌为主要防锈颜料,协同云母氧化铁灰,制备无溶剂型环氧防腐涂料.考察涂层的基本性能,并采用交流阻抗(EIS)测试技术,分析了颜料体积浓度(PVC)、活性稀释剂和防锈颜料质量比对涂层防腐性能的影响.实验结果表明:该涂料固含量高达98%以上,是环境友好型涂料;PVC小于12%时,涂层具有较好的防腐性能;PVC为8%,活性稀释剂添加量为2%,云铁灰与磷酸锌质量比为1:4时涂层的防腐性能最佳.在涂层浸泡一定时间后,磷酸锌能防止腐蚀的进一步发生,起到有效抑制腐蚀的作用.     

Phosphate Removal from Aqueous Solution Using Coir-Pith Activated Carbon

The present study deals with the removal of phosphates from aqueous solution using activated carbon developed from coir pith. Batch adsorption experiments were performed to delineate the effect of initial pH, contact time, adsorbent dose and temperature on the removal of phosphates by coir-pith activated carbon (CAC) (activated by H₂SO₄). The removal was found to be maximum in the pH range of 6–10. The kinetics of adsorption showed that the phosphate adsorption onto CAC was a gradual process with a quasi-equilibrium being attained in 3 h. The adsorption equilibrium data followed the Temkin isotherm. Thermodynamic parameters such as ΔG ^o , ΔH ^o , and ΔS ^o were evaluated by applying the Arrhenius and van't Hoff equations, and it was found that the adsorption of phosphate on CAC was spontaneous and endothermic.     

钢渣对废水中磷的吸附行为

通过批次振荡实验研究了钢渣吸附磷的特性. 结果表明,钢渣对磷的吸附过程符合Langmuir和Freundlich方程,理论饱和吸附量为0.33 g/kg,为优惠型吸附. 吸附动力学过程符合Lagergren准二级动力学方程,平衡吸附量随温度升高而增加,吸附速率主控步骤为液膜扩散和颗粒内扩散同时存在. 吸附热力学参数DH>0, DG<0, DS>0,钢渣对磷的吸附为吸热、自发的物理吸附过程,升高温度有利于吸附进行.