沸石负载纳米氧化铁处理氮磷污水研究

采用共沉淀法制备了沸石负载纳米氧化铁复合材料(沸石@Fe_3O_4),并采用静态吸附试验探究了pH、吸附动力学、等温吸附模型及热力学等对沸石@Fe_3O_4吸附模拟氨氮废水溶液的影响。试验表明,当溶液pH为6时,沸石@Fe_3O_4对水中氨氮的吸附能力达到最高值,随溶液中pH的升高,沸石@Fe_3O_4对水中磷的吸附能力逐渐降低。可采用准二级动力学模型描述沸石@Fe_3O_4对水中氨氮和磷的吸附动力学过程。Langmuir吸附等温线模型的线性拟合结果表明,氨氮和磷最大理论单位吸附量分别为7.92和9.09mg/g。     

沸石柱吸附钨冶炼废水中氨氮的试验研究

用沸石填料柱建立模拟装置,研究沸石吸附模拟氨氮废水和钨冶炼废水的动态规律、再生性质、穿透曲线、水力负荷曲线,吸附动力学等。试验结果表明,进水速度为2.72 BV时,处理氨氮浓度为50 mg·L-1模拟废水和98 mg·L-1钨冶炼废水,在穿透点分别为C/C0=0.3和0.15时,天然沸石柱可处理水量分别为126 BV、43 BV,改性后沸石柱可处理水量分别为157 BV、46 BV;随水力负荷增大,沸石柱可处理水量减小;吸附饱和沸石用8%NaCl溶液解吸再生效果好,成本低,但再生后的沸石吸附容量会变小;动力学分析发现,沸石柱吸附氨氮速度较快,是处理氨氮废水的优良吸附材料。     

吸附去除水产养殖中氨氮研究进展

介绍了吸附去除水产养殖中氨氮的重要性和优点,讨论了水的pH值、所含金属离子和有机物对吸附去除氨氮效果的影响,对常用的活性炭吸附剂、树脂吸附剂、沸石吸附剂和其他矿石、废弃物吸附剂的改良研究进行了比较,指出了其存在的一些问题,并对研究方向进行了展望.     

沸石处理稀土生产中氨氮废水的实验研究

为实现稀土生产中氨氮废水的治理,选用天然吸附材料沸石,用它的吸附和离子交换性能来处理稀土生产中的氨氮废水,采用静水和动水两种方法进行实验。实验结果表明,用沸石处理工业废水中的氨氮,去除率达50%以上。     

沸石矿物处理污水中重金属离子的实验

沸石是一种多孔的含水架状硅酸盐类矿物,经物理法活化和化学法改型后制成离子交换剂(吸附剂),可增强沸石矿物的吸附和离子交能力,对处理污水中重金属离子有一定的效果。本文通过试验证实了铵型和钠型沸石对Zn~(2+)、Cu~(2+)的交换容量较好,且交换剂制造工艺成本低、设备简单、操作方便。     

天然沸石去除地下水中氨氮的研究

针对地下水中氨氮(NH<,4>-N)污染,采用天然沸石进行了试验研究,探讨了沸石种类、振荡强度、pH、吸附等温线等因素对去除地下水中氨氮的影响.结果表明,天然沸石对NH<,4>-N具有"快速吸附、缓慢平衡"的特点,浙江缙云沸石对地下水中NH<,4>-N具有较好的去除能力.当反应时间≤3 h,高振荡强度(200 r/min)的NH<,4>-N去除率大于低振荡强度(100 r/min)的;振荡强度显著影响NH<,4>-N的去除效果.当pH介于2.59～10.66时,去除率为74.23%～93.71%.中性初始pH(5.76～8.55)利于NH<,4>-N的吸附去除,酸性(pH≤2.59)导致去除率略有下降,而碱性(pH≥10.66)致使去除率急剧下降.缙云沸石的Langmiur吸附等温公式为:Q=0.964 8μ/(1+0.181 0μ),而Freundlich吸附公式为:Q=0.815 8μ0.576 2,椎荐采用后者.     

几种常见离子交换材料在氨氮废水处理中的应用

氨氮不仅是生活污水主要污染物之一,也是引起水体富营养化主要因素之一.不少研究对蛭石、蒙脱石、沸石、离子交换树脂等常见离子交换材料在氨氮废水处理中的应用进行了探索,取得了不同的处理效果.文中基于已有研究结果,对这几种常用离子交换材料的结构特性、离子交换和吸附机理进行了对比分析,介绍了其在氨氮废水处理中的应用现状,对将离子交换法和生物法联合实施氨氮废水综合治理的新策略及其应用前景进行了探讨.      

4A 沸石对锰渣渗滤液中 Mn2＋吸附-解吸研究

在开展4A 沸石吸附—解吸模拟锰渣渗滤液中 Mn2＋实验的基础上,通过 X 射线衍射分析（XRD）和红外光谱分析（FTIR）研究了4A 沸石吸附 Mn2＋的机制及其解吸行为。结果表明：4A 沸石对模拟锰渣渗滤液中 Mn2＋的去除效率高达99．34％,吸附量最高可达92．84 mg／g,但化学解吸和化学—物理联合解吸对于沸石型离子交换吸附的解吸效果不佳,Mn2＋解吸率均未超过1．6％。XRD 和 FTIR 显示4A 沸石对 Mn2＋的吸附机制主要为离子交换。     

超声波作用下用人造沸石从废水中吸附磷

研究了超声波作用下用人造沸石从含磷废水中吸附磷,考察了超声波功率、吸附时间、人造沸石用量、磷初始质量浓度对磷吸附率的影响,对比了硅藻土、活性氧化铝对磷的吸附效果,在最佳条件下,通过动力学试验,利用Morris扩散模型研究了人造沸石吸附磷的机制。结果表明:在超声波功率40 W、吸附时间50min、人造沸石加入量2.5g、磷初始质量浓度20mg/L条件下,磷吸附率达99.5%;人造沸石的吸附效果比硅藻土和活性氧化铝吸附效果好;磷的吸附动力学特征很好地遵循Morris扩散模型。     

抗菌吸附材料的制备及其在再生水处理的应用

以具有良好脱氮效果的改性沸石为原材料,制备抗菌吸附材料.将其用于处理大肠菌群浓度和氨氮含量较高的市政污水厂二级出水结果表明,分别采用银、锌和铜三种金属离子制备抗菌吸附材料,其中银离子的抗菌性能最好,有助于氨氮的去除.最佳制备条件为:AgNO3用量85mg.g-1,pH6～7,制备时间120min,制备温度40℃,转速150r.min-1.优化后材料的载银量为49.79mg.g-1.将该材料应用于再生水处理,在混合投加抗菌吸附材料0.5g.L-1和沸石2g.L-1条件下,反应120min,该材料的杀菌率98.87%,氨氮去除率66.54%,剩余氨氮的质量浓度为8.36mg.L-1,出水达到城市杂用水水质指标.     

金属基树脂对含盐氨氮废水的吸附研究

盐分的存在使得氨氮废水的处理难度大大增加。在含盐条件下,利用负载过渡金属(Co2+、Ni2+、Cu2+、Zn2+)的D001树脂和D751树脂对氨氮废水进行了吸附实验。与负载前树脂相比,金属基D001(D751)树脂比表面积增大,且吸附氨氮后树脂形貌更为有序; 5次循环吸附氨氮后各金属离子依然牢固地固定在树脂上,说明金属基D001(D751)树脂稳定性较好。吸附动力学研究发现,金属基D001(D751)树脂对氨氮的吸附过程符合准二级动力学,且在吸附氨氮过程中吸附剂与吸附质之间存在由电子转移或共享产生的化学作用力。对金属基树脂对含盐氨氮废水吸附机理进行了剖析,结果表明金属基树脂与溶液中的氨氮存在配位吸附作用,通过配位共价键键合形成配体络合物。      

光催化技术在中低浓度氨氮废水处理中的应用

对比分析有色冶金生产过程产出的中低浓度氨氮废水处理技术,利用实验室小试考察了吹脱法、折点氯化法、药剂沉淀法和光催化技术脱除废水中氨氮的效果。结果表明,采用光催化技术处理废水,氨氮脱除率为90%～99%。在此基础上开发了一套能力为40m~3/d错流式光催化有色金属氨氮废水处理装置,将此工艺及装备用于处理氨氮浓度为266.74～1 509.79 mg/L的实际工业废水,处理后废水中氨氮含量小于20mg/L,脱除率平均为72%,最高达到93.3%。     

吹氨冶炼高氮钢的原理与实验

根据冶金热力学的计算结果,提出了钢液-气相界面可能发生的NH3和[O]、[S]耦合反应.该界面反应过程促使NH3在钢液界面生成易被钢液吸收的活性氮原子,同时,脱除了钢液中的氧、硫杂质元素,与常压下钢液吹氮增氮的工艺比较,可以取消为增氮而采用的钢液预脱氧、脱硫工艺环节,减少钢中非金属夹杂物的生成.10 kg中频感应炉的冶炼实验结果表明,合金成分相同的钢液供给等摩尔氮含量的氮化介质,NH3比N2的增氮效果提高了18%～75%.吹NH3条件下,钢液中保持一定量的氧、硫表面活性元素,有利于氮的吸收.     

Principle and Practice of High Nitrogen Steel Melting by Blowing Ammonia Gas

During the high nitrogen steel (HNS) melting process, the absorption reaction of nitrogen in the liquid steel by blowing NH_3 and N_2 was investigated respectively. In order to obtain higher content of nitrogen in steel, the liquid steel should be deoxidized and desulfurized because the oxygen and sulfur as surface activity element are not fa-vorable to the absorption of nitrogen in melting process. Based on the metallurgical thermodynamics, the coupling re-action of NH_3 with oxygen can improve the generation of activity nitrogen atom in liquid steel. Nitrogen atom is easi-er to be absorbed than nitrogen molecule. At the same time, blowing ammonia gas can remove the oxygen from liquid steel and decrease the inclusion in the steel. Experiments of HNS melting were carried out in a 10 kg induction fur-nace, and the results indicated that for liquid steel containing the same content of alloys and blowing the same mole of nitrogen, the absorption effect of nitrogen by blowing NH_3 is obviously higher than that of blowing N_2. The techni-cal process of melting HNS by blowing NH_3 under normal pressure is feasible in industrial production.     

Changes in nitrogen metabolism in young cattle following ultraviolet irradiation and feeding on urea

Some indexes of nitrogen metabolism in blood, rumen content and urine of bull-calves fed on urea were studied as affected by UV-radiation. The content of protein, nonprotein, amine nitrogen, urea and ammonia in the rumen content and blood as well as as intensity of urea nitrogen and ammonia excretion with urine were determined. It is established that when 25% of protein necessary for the organism was replaced in the ration by urea, UV-radiation with a dose of 120 merg/h-m2 lowers already at the beginning of irradiation the amount of amine nitrogen and further the protein one in the young cattle rumen content. In blood of the irradiated bull-calves at the beginning of irradiation the level of amine nitrogen decreases, the level of nonprotein nitrogen lowers with a longer irradiation. The content of protein nitrogen in blood at that time increases. It was found that the content of ammonia in the bull-calves rumen during the first twenty-hours lowers, the amount of urea in blood does not change essentially. Simultaneously the ammonia excretion with urine intensifies, at the same time the excretion of urea nitrogen with urine does not differ essentially from that in the control bull-calves. In the bull-calves under study the nitrogen balance and average daily gains increase that may testify to the fact that UV-radiation in the applied dose stimulates a more complete utilization of urea nitrogen for the synthesis processes in the organism.     

Principle and Practice on High Nitrogen Steel Melting by Blowing Ammonia Gas

 Abstract: During the HNS melting process, the absorption reaction of Nitrogen in the liquid steel by blowing NH3 and N2 was investigated respectively. In order to obtain higher content of nitrogen in steel, the liquid steel should be deoxidized and desulfurized because the [O] and [S] as surface activity element is not favorable to absorb nitrogen in melting process. Based on the metallurgical thermodynamics, the coupling reaction of NH3 with [O] can improve the generation of activity nitrogen atom in liquid steel. Nitrogen atom is easier to be absorbed than nitrogen molecule. At the same time, blowing ammonia gas can remove the oxygen from liquid steel and decreased the inclusion in the steel. Experiments of HNS melting in ten-kilogram inductive furnace indicated that, for liquid steel with same content of alloys and blowing the same mole of nitrogen , the absorption effect of nitrogen by blowing NH3 increase 18~75% than that of blowing N2.The technical process of melting HNS by blowing NH3 under normal pressure is feasible in industry production.h     

HMBR法处理某黄金矿山氨氮废水试验研究

针对某黄金矿山外排水氨氮浓度较高的特点,采用复合式膜生物反应器(HMBR)系统进行处理。研究了在好氧区pH为弱酸性及中性条件下,HMBR法对氨氮和COD等典型污染物的去除特征。试验确定了HMBR法最佳工艺参数:好氧区pH值控制为6.80~7.20,DO为2~3 mg/L,动态曝气运行周期6 min(运行-间歇时间4 min^-2 min),在线化学清洗措施为“柠檬酸+水-次氯酸钠”,水力停留时间为2.34 d,HMBR出水中氨氮和COD均达到GB 8978—1996《污水综合排放标准》一级要求。该研究为HMBR法处理氨氮废水的工业化应用提供数据支持。     

Effect of feeding clinoptilolite (zeolite) on the performance of three strains of laying hens

1. One hundred and twenty 16-week-old single combed pullets of three strains were fed on a diet containing 135 g protein/kg with or without 50 g clinoptilolite/kg in a trial with 20 hens per treatment. Sterile river sand replaced clinoptilotile in the control diet in order to keep the diets isoenergetic. The hens were individually caged in a naturally ventilated laying house and fed one of the two diets for ten 28-d periods. 2. Significant dietary effects of feeding clinoptilolite were observed with number of eggs laid per hen, shell thickness, efficiency of food utilisation and droppings moisture content. No significant dietary effects between treatments were observed with body weight, age at first egg, egg weight. Haugh units, food intake/hen and rate of amino acid absorption of radioactive lysine and methionine into the bloodstream. Significant differences between strains were observed with regard to all parameters except food intake/hen. There were no significant strain X clinoptilolite interactions.     

Kinetics of interaction of porous titanium with gaseous ammonia

The kinetics of interaction of porous titanium (getter) with gaseous ammonia is studied using thermogravimetry, X-ray diffraction, and mass spectrometry. The weight variation of porous titanium in an ammonia atmosphere and mass-spectrometric data are used to determine the kinetic constants of the chemical reaction of titanium with ammonia. A mechanism for the chemical reaction is proposed; it is based on the concept of competing reactions of interaction of hydrogen and nitrogen with titanium.     

低碳锰铁 FeMn 84C 0.4 氮化的实验研究

应用真空电阻炉高温渗氮、X射线衍射分析等实验测试方法，研究了粒度、温度、气相组成等因素对低碳锰铁氮化的影响。工业用气态氮作为渗氮气体的主要气相组成，可同时发生锰铁的氮化和氧化，生成 Mn4N 和 MnO 化合物；随渗氮温度的提高，锰氧化物的含量相应增高。渗氮气氛中配加氨气，使氮气的分压相应降低，平衡吸附浓度降低，渗氮试样的含氮量降低。