Removal of antibiotics from aqueous solution by using porous adsorbent templated from eco-friendly Pickering aqueous foams

The aqueous foam template without any solvent and only using the particles stabilizer has attracted much attention for preparation of the porous adsorbents. Herein, a novel porous adsorbent was fabricated via thermal-initiated polymerization of Pickering aqueous foams, which was stabilized by the natural sepiolite (Sep) and pine pollen, and utilized for the removal of antibiotic from aqueous solution. The stabilizing mechanism of Pickering aqueous foam of that the Sep was modified with the leaching substance from pine pollen and arranged orderly around the bubble to form a dense “shell” structure was revealed. The adsorbents possessed the hierarchical porous structure and excellent adsorption performance for antibiotic of chlorotetracycline hydrochloride (CTC) and tetracycline hydrochloride (TC). The equilibrium adsorption capacities of CTC and TC were achieved with 465.59 and 330.59 mg/g within 60 min at 25°C, respectively. The adsorption process obeyed Langmuir model and pseudo-second-order adsorption kinetic model. This work provided eco-friendly approach for fabricate porous adsorbents for wastewater treatment.     

锰氧化物/石英砂(MOCS)对铜和铅离子的吸附研究

研究了锰氧化物/石英砂(MOCS)吸附剂对Cu2+和Pb2+的吸附行为,考察了吸附剂用量、平衡时间、温度、盐浓度、溶液的pH值等因素对MOCS吸附的影响.结果表明,MOCS对Cu2+和Pb2+的吸附在3 h基本达到吸附平衡,吸附量随着溶液的pH值增大、温度的升高以及盐浓度的降低而增加,在单一体系以及混合体系中对Cu2+和Pb2+的吸附均符合Langmiur吸附等温式,温度从15 ℃升高到45℃,Cu2+和Pb2+的饱和吸附容量(qm)分别从13.4 μmol·g-1和15 5μmol·g-1升高到16.4μmol·g-1和18.1μmol·g-1.Cu2+和Pb2+吸附反应的ΔG°均为负值,焓变ΔH°为正值,说明该吸附过程是自发的吸热反应.利用准一级动力学方程、准二级动力学方程以及粒子扩散方程的数学模型检验了吸附过程的动力学性质,表明MOCS对Cu2+和Pb2+的吸附过程符合准二级反应动力学模型.计算了不同温度下3个动力学方程的吸附速率常数K值.根据准二级反应的吸附速率常数K值,求得MOCS对Cu2+和Pb2+的吸附活化能(Ea)分别为92.3 kJ·mol-1和119 kJ·mol-1.在混合体系中,共存离子的存在影响金属离子的吸附效率;Cu2+存在时,Pb2+的饱和吸附量下降了24.4%,而Pb2+存在时,Cu2+的饱和吸附量下降了93.8%.MOCS对Cu2+和Pb2+的吸附强弱顺序为Pb2+＞Cu2+.     

氨化酒糟吸附剂去除电镀废水中六价铬研究

以酿酒过程中产生的酒糟为原料,制备得到氨化酒糟吸附剂,用于去除电镀废水中的六价铬〔Cr(Ⅵ)〕,利用FTIR、EDS、BET和SEM等对吸附剂组成和结构进行分析和表征,在不同的pH及吸附剂投加量条件下研究其对Cr(Ⅵ)吸附性能的影响。结果表明:氨化酒糟吸附剂表面引入了大量的氨基,氮元素占比达到4.40%,其比表面积增至25.67 m ²/g;当平衡pH为2.7时,Cr(Ⅵ)的饱和吸附量达到150.45 mg/g,平均吸附速率达到1 791.90 mg/(g·h);经过5次再生循环后,氨化酒糟吸附剂对Cr(Ⅵ)的吸附量达到98.44 mg/g,吸附性能损失率仅为19.60%。     

包埋固定化海洋硅藻吸附材料的制备及其对水中铅离子的吸附特性研究

采用海藻酸钠(SA)凝胶包埋法对海洋硅藻藻粉进行固定化,考察了藻粉用量、海藻酸钠浓度、Ca Cl2质量分数、交联时间及小球粒径对固定化小球吸附铅离子性能的影响,并研究了这种吸附材料对Pb~(2+)的吸附特性.结果表明,固定化海洋硅藻生物吸附剂的最佳制备条件为:藻粉用量5.0 g/100 m L SA、海藻酸钠浓度20 g·L~(-1)、Ca Cl2质量分数0.5%、交联时间1 h、小球粒径2.8 mm左右.Langmuir等温吸附模型能够较好地描述固定化小球吸附对Pb~(2+)的等温吸附特征,R2为0.9983,最大理论吸附量为833.33 mg·g~(-1).准二级动力学模型能够较好地拟合固定化小球吸附Pb~(2+)的动力学过程,理论平衡吸附量为714.29 mg·g~(-1),与实验所得平衡吸附量706.55 mg·g~(-1)较为接近.固定化小球吸附Pb~(2+)的适宜初始p H值为4~5.Na Cl、Ca(NO3)2、Mg(NO3)2对固定化小球的吸附性能有一定的促进作用.本研究所制固定化海洋硅藻球形吸附材料对Pb~(2+)的吸附容量明显优于大部分研究所报道的固定化生物吸附剂,是一种很有潜力的生物吸附材料.     

水合氧化镧吸附除磷的试验研究

以开发新型高效除磷吸附剂材料为目的,以金属水合氧化物MeH(metal hydrate)为试验对象,对所选材料进行了吸附除磷性能评价.通过对多种水合金属氧化物吸附除磷性能的比较研究,发现水合氧化镧LaH(lan-thanum hydrate)具有优异的除磷吸附容量,其吸附容量大约为参照物粉末活性氧化铝的十几倍.该吸附剂的吸附容量随pH值变化显著,在pH=3附近达最大值;吸附等温线较符合Langmuir方程;进行了抗无机阴离子干扰能力测试,给出了干扰离子的影响顺序;该吸附剂对正磷酸根的去除性能优越,但对聚磷酸根的去除效果不理想.试验结果表明,水合氧化镧在平衡吸附容量、pH适应范围等方面与参照物活性氧化铝相比较,具有优异的性能.     

蔗渣吸附剂的制备及其对氨氮的吸附研究

从炭化蔗渣的炭化温度和用量,吸附动力学、吸附温度,溶液的酸度、组成,吸附等温线及氨氮的存在形式等方面探讨了实验制备的炭化蔗渣吸附去除溶液中氨氮的影响因素。结果表明,直接炭化法蔗渣吸附剂制备的最佳炭化温度为400℃;在初始氨氮浓度一定的条件下,随着吸附剂投加量的增大,炭化蔗渣对氨氮的吸附量减少;炭化蔗渣吸附氨氮的动力学曲线符合准二级动力学模型,吸附常数K2=3.59g(/mg/min);当pH=9.20时炭化蔗渣对氨氮的最大吸附量为10g/kg;在实验的pH范围内,pH=10时炭化蔗渣对氨氮的吸附去除最好;直接炭化法蔗渣吸附剂对氨氮吸附去除的最佳温度是40℃;pH为3.98～9.20时吸附等温线可用Langmuir与Freundlich吸附等温方程进行拟合。     

酸-碘改性壳聚糖-膨润土脱除单质汞特性及机理分析

为探明烟气中酸性气体(SO2,NO,HCl)和H2O对酸-碘改性壳聚糖-膨润土吸附剂脱除单质汞(Hg0)的影响和脱除机理,在小型固定床试验台架上开展了Hg0脱除的实验研究.结果表明:由于SO2与Hg0在吸附剂表面活性位上存在竞争吸附,SO2抑制吸附剂对Hg0的脱除.H2O和较高浓度(1000μg/m3)的NO对脱汞具有明显地促进作用.由于低温下HCl与Hg0较高的反应能垒,HCl对脱汞没有影响.与单一烟气成分影响相比,在SO2、NO、HCl和H2O的联合作用下,吸附剂的长时间脱汞性能得到大幅提高.机理分析表明壳聚糖首先被酸中的H+质子化,之后再吸附酸与KI反应生成的I2,进而有效地吸附Hg0.量子化学计算表明壳聚糖在酸性条件下对I2具有良好的吸附特性,改性壳聚糖吸附剂对Hg0具有较好的吸附能力,其吸附能约为127kJ/mol.     

核桃青皮生物炭对重金属铅、铜的吸附特性研究

采用500℃限氧裂解法将农林废弃物核桃青皮制成核桃青皮生物炭,进行了核桃青皮生物炭对铅、铜的批量吸附实验.同时,利用扫描电镜、FTIR红外等方法探讨了核桃青皮炭吸附Pb~(2+)、Cu~(2+)的特性,探究了吸附时间、溶液初始浓度、吸附温度、吸附剂投加量、溶液初始pH等因素对核桃青皮生物炭吸附Pb~(2+)、Cu~(2+)作用的影响,讨论了吸附动力学特性及吸附等温特性.结果表明:温度298.15 K、pH为3~6条件下,核桃青皮生物炭吸附Pb~(2+)和Cu~(2+)在20 min内即可达到吸附平衡,核桃青皮炭最佳投加量分别为0.8、1.5 g·L~(-1),最大吸附量分别为476.190、153.846 mg·g~(-1);吸附过程符合准二级动力学方程,等温吸附曲线符合Langmuir方程,说明其吸附过程主要是近似单分子层的化学吸附.     

铁-铈水合氧化物吸附剂除磷的间歇试验研究

采用共沉淀法合成铁-铈水合氧化物脱磷吸附剂，进行其对水溶液中磷酸盐吸附的速率曲线、pH值影响曲线、吸附等温线等的测定。结果显示，该复合吸附剂在pH=2～6范围内均具有良好的吸附除磷效果，其最大静态吸附量是粉末活性氧化铝的1.8倍以上。对富磷吸附剂的解吸及再生试验显示，该吸附剂可循环使用，一次再生后吸附容量约为新鲜吸附剂容量的90％。     

制备条件对硅胶负载氧化锆吸附除氟的影响

应用浸渍法制备了硅胶负载氧化锆除氟吸附剂,研究了焙烧温度、硅胶粒度、浸渍时间、浸渍温度、浸渍液浓度、浸渍固液比和浸渍次数等制备参数对吸附剂吸附容量的影响.实验发现焙烧温度有较大影响,450℃焙烧有最大的吸附量,再升高温度吸附量迅速下降.浸渍可在2h内达到平衡.浸渍温度越高,浸渍液浓度越高,则吸附容量越大.采用较高浓度一次浸渍优于低浓度多次浸渍.硅胶粒度和浸渍固液比也影响吸附量,粒度越大吸附量越小,粒度小于0.25mm后吸附量趋于稳定.     

Heavy metals removal from aqueous solution using carbonaceous K_2S-impregnated adsorbent

A novel carbonaceous adsorbent for heavy metal removal was prepared from raw coal by one-step simple sulfur impregnation using K_2S. Raw coal was mixed with K_2S powder and then heated at 800℃ for 30 min in nitrogen to produce K_2S char. The sulfur content and form in K_2S char were determined, and the ability of K_2S char to adsorb Zn~(2+), Cd~(2+) and Pb~(2+) was examined. The K_2S impregnation was effective at impregnating sulfur into coal, especially in the form of elemental, thiophenic and sulfatic sulfur. The sulfur content of K_2S char was higher than those of raw coal and pyrolysis char. The Zn~(2+) removal in 2.4 mmol/L of Zn~(2+) solution by K_2S char was higher than raw coal with the removal rate of 100%. K_2S char adsorbed Pb~(2+) and Cd~(2+) in 24 mmol/L of Pb~(2+) and Cd~(2+) solution with the removal rate of 97 % and 35 %, respectively. The elution extents of adsorbed Pb~(2+) and Cd~(2+) were zero in distilled water and 27% in 0.1 mol/L HCl solution. These results indicated that an effective adsorbent for heavy metal ions was prepared from coal using K_2S sulfur impregnation, and that the adsorbed metals were strongly retained in K_2S char.     

Heavy metal removal from aqueous solution using carbonaceous K2S-impregnated adsorbent

A novel carbonaceous adsorbent for heavy metal removal was prepared from raw coal by one-step simple sulfur impregnation using K2S. Raw coal was mixed with K2S powder and then heated at 800°C for 30 min in nitrogen to produce K2S char. The sulfur content and form in K2S char were determined, and the ability of K2S char to adsorb Zn2+, Cd2+ and Pb2+ was examined. The K2S impregnation was e ective at impregnating sulfur into coal, especially in the form of elemental, thiophenic and sulfatic sulfur. The sulfur content of K2S char was higher than those of raw coal and pyrolysis char. The Zn2+ removal in 2.4 mmol/L of Zn2+ solution by K2S char was higher than raw coal with the removal rate of 100%. K2S char adsorbed Pb2+ and Cd2+ in 24 mmol/L of Pb2+ and Cd2+ solution with the removal rate of 97% and 35%, respectively. The elution extents of adsorbed Pb2+ and Cd2+ were zero in distilled water and 27% in 0.1 mol/L HCl solution. These results indicated that an e ective adsorbent for heavy metal ions was prepared from coal using K2S sulfur impregnation, and that the adsorbed metals were strongly retained in K2S char.     

富磷废弃钙基生物炭对水体中铅的去除

基于磷酸盐和碳酸盐对铅的高亲和特性,将蛋壳与厨余垃圾煅烧制备的含钙生物炭除磷后（ES-BC/P）,用于水体中铅的去除.结果表明,ES-BC/P在较优的投加量下对不同浓度的铅（1~100 mg·L^-1）均具有较好的去除性能,去除效率均高于99%,且反应后磷的释放量较低;ES-BC/P偏碱性,因含铅污染液呈弱酸性,ES-BC/P加入后无需调节体系的pH值即可达到较好的去除效果;反应动力学及等温线实验表明,ES-BC/P除铅主要为单层化学吸附,最大吸附容量为493.12 mg·g^-1（318 K）;表征分析结果表明,铅主要通过与ES-BC/P中的Ca-P化合物和CaCO₃进行反应,Pb²⁺可与Ca²⁺发生交换作用,形成 Pb₅（PO₄）₃OH、Pb₁₀（PO₄）₆（OH）₂、PbCO₃和Pb₃（CO₃）₂（OH）₂等沉淀而被去除.综上所述,除磷后的ES-BC材料可实现水体中铅的高效去除,从而实现废弃物的资源化利用.     

磺化生物炭活化过硫酸盐去除水中盐酸四环素

采用高温煅烧-磺化法制备磺化改性苎麻生物炭（SBC）,并将其作为过硫酸盐活化剂,实现了对水中盐酸四环素（TCH）的高效去除.通过扫描电子显微镜（SEM）、比表面积分析仪（BET）、傅里叶变换红外光谱（FT-IR）对SBC的形貌和结构进行表征,研究了溶液初始pH值、SBC投加量、PS投加量对SBC/PS体系中TCH降解效果的影响,并考察了SBC的重复利用性能.结果表明,SBC为片层介孔材料,其表面含有丰富的含氧官能团和黄原酸酯官能团.在初始pH值为3,PS投加量为10mmol/L,SBC投加量为0.5g/L的最优条件下,反应180min后,SBC/PS体系对TCH的去除率达到89.0%,明显优于SBC、苎麻秸秆原始生物炭（BC）、PS和BC/PS体系.在实验考察范围内,SBC/PS体系对TCH的降解性能随pH值（pH=3~11）的升高呈先降低后升高再降低的趋势;随SBC和PS投加量的升高,TCH的去除率呈先上升后下降的趋势.自由基淬灭实验和电子顺磁共振（EPR）实验表明,SBC/PS体系降解TCH的过程中产生了硫酸根自由基（SO₄^-·）、羟基自由基（·OH）、超氧自由基（O₂^-·）和单线氧（¹O₂）,¹O₂起主导作用.循环利用实验结果表明,SBC表现出良好的重复利用性能.研究认为SBC是一种环境友好、高效的非金属碳基过硫酸盐活化剂,具有良好的应用前景.     

Removal of trace arsenic（V） and phosphate from water by a highly selective ligand exchange adsorbent

The ligand exchange adsorbent could be used to remove the toxic arsenic(V) and phosphate efficiently from water even in the presence of foreign anions and possible to apply in chemical industry.     

Removal of arsenate and arsenite from aqueous solution by waste cast iron

The removal of As(III) and As(V) from aqueous solution was investigated using waste cast iron, which is a byproduct of the iron casting process in foundries. Two types of waste cast iron were used in the experiment: grind precipitate dust (GPD) and cast iron shot (CIS). The X-ray diffraction analysis indicated the presence of Fe0 on GPD and CIS. Batch experiments were performed under different concentrations of As(III) and As(V) and at various initial pH levels. Results showed that waste cast iron was effective in the removal of arsenic. The adsorption isotherm study indicated that the Langmuir isotherm was better than the Freundlich isotherm at describing the experimental result. In the adsorption of both As(III) and As(V), the adsorption capacity of GPD was greater than CIS, mainly due to the fact that GPD had higher surface area and weight percent of Fe than CIS. Results also indicated the removal of As(III) and As(V) by GPD and CIS was influenced by the initial solution pH, generally decreasing with increasing pH from 3.0 to 10.5. In addition, both GPD and CIS were more effective at the removal of As(III) than As(V) under given experimental conditions. This study demonstrates that waste cast iron has potential as a reactive material to treat wastewater and groundwater containing arsenic.     

电晕放电等离子体技术处理水中四环素的研究

采用电晕放电等离子体技术降解水中的四环素,研究了在反应体系中,初始浓度、输入功率、电极间距、空气流量及初始pH对四环素去除效率的影响.同时,还对四环素在降解过程中不同时段的COD、TOC和B/C变化进行了研究,并对其降解产物进行了分析和讨论.实验结果表明:电晕放电等离子体对水中四环素具有较好的去除效果,在四环素初始浓度为200 mg·L-1、pH=2.47、初始电导率为1.50 mS·m-1、空气流量为0.06 m3·h-1、电极间距为4 mm、输入功率为45.0 W的条件下,反应20 min后,四环素的去除率可达到99.1%,COD去除率可达31.2%,TOC去除率可达80%左右,其B/C比提高为0.30,有效地改善了废水的可生化性.     

复配表面活性剂水溶液处理甲苯气体的研究

以非离子表面活性剂吐温-20(Tween-20)为主表面活性剂,添加助表面活性剂十二烷基苯磺酸钠(SDBS)以及助剂氯化钠,形成复配水溶液吸收剂处理VOCs废气.以甲苯为VOCs的典型代表,研究了Tween-20,Tween-20/SDBS和Tween-20/SDBS/氯化钠3种水溶液吸收剂的临界胶束浓度(CMC)及其对甲苯去除率的影响.结果表明,当表面活性剂浓度达到CMC时,水溶液对甲苯的吸收效果开始明显增强,加入助表面活性剂SDBS和助剂氯化钠有利于甲苯的去除,同时可降低溶液的CMC,减少表面活性剂的用量,降低水溶液吸收法处理VOCs成本.当空气流量G为300mL/min、液体喷淋量L为75mL/min、进口甲苯浓度800mg/m3、温度T为30℃时,分别以Tween-20、Tween-20/SDBS(摩尔比1/4)和Tween-20/SDBS/氯化钠(摩尔比1/4/0.1)的水溶液为吸收剂,且浓度均为1CMC时,甲苯去除率分别为56%、70%和77%,三元复配表面活性剂水溶液的吸收效果最佳.     

Regenerable adsorbent for removing ammonia evolved from anaerobic reaction of animal urine

The waste gas evolved from biodegradation of animal urine contains ammonia causing environmental concerns. A new and effective method for removing ammonia from such waste gas using reactive adsorption is presented. In the process, activated carbon impregnated with H2SO4（H2SO4/C） is employed. Ammonia in the waste gas reacts with H2SO4 on the adsorbent instantaneously and completely to form （NIL）2SO4. The H2SO4/C adsorbent is high in NH3 adsorption capacity and regenerable. The NH3 removal capacity of this regenerable adsorbent is more than 30 times that of the adsorbents used normally in the industry. The spent H2SO4/C is regenerated by flowing low-pressure steam through the adsorbent bed to remove the （NH4）2SO4 from the adsorbent. The regeneration by-product is concentrated （NH4）2SO4 solution, which is a perfect liquid fertilizer for local use. Re-soaking the activated carbon with H2SO4 solution rejuvenates the activity of the adsorbent. Thus the H2SOJC can be reused repeatedly. In the mechanism of this reactive adsorption process, trace of H20 in the waste gas is a required, which lends itself to treating ammonia gas saturated with moisture from biodegradation of animal urine.     

Biosorption of cadmium(Ⅱ) and lead(Ⅱ) ions from aqueous solutions onto dried activated sludge

The removal of heavy-metal ions from aqueous solutions by using dried activated sludge has been investigated in batch systems. Effect of solution pH, initial metal ion concentration, and temperature were determined. The results of the kinetic studies showed that the uptake processes of the two metal ions（Cd（Ⅱ） and Pb（Ⅱ）） followed the pseudo-second-order rate expression. The equilibrium data fitted very well to both the Langmuir and Freundlich adsorption models. The FT-IR analysis showed that the main mechanism of Cd（Ⅱ） and Pb（Ⅱ） biosorption onto dried activated sludge was their binding with amide I group.