改性红辉沸石去除水溶液中氨氮的初步研究

文章研究了采用酸、碱、盐改性红辉沸石和加热活化红辉沸石对改性红辉沸石去除水溶液中氨氮的影响效果。实验结果表明：（1）用红辉沸石去除溶液中氨氮的实验条件选择如下：1搅拌时间为30min;2沸石粒度为40～60目;3沸石用量为2g;4氯化氨溶液浓度为40mg/L;5氯化氨溶液用量为80ml。（2）采用高温活化对提高红辉沸石去除氨氮效率的作用不明显。（3）酸和碱改性对提高红辉沸石去除氨氮的效率有一定的作用,其中盐酸改性的红辉沸石去除氨氮效率为16.2%,硫酸改性的红辉沸石去除氨氮效率为13.1%,碱改性的红辉沸石去除氨氮效率为25.6%。（4）盐改性对红辉沸石去除水溶液中氨氮的影响效果巨大：经盐改性后,去除率由9.6%升高至72.6%。     

以改性蛭石为填料的生物流化床法处理低C /N污水的应用

以热改性蛭石为填料,提高生物流化床系统处理低C/N污水的能力。实验结果表明,经过改性的蛭石对氨氮和COD的去除效率有明显的提高,分别是天然蛭石的2.1倍和2.7倍。在热改性蛭石为填料的生物流化床系统处理低C/N污水的实验过程中,主要分析了温度、pH和DO对反应系统处理效果的影响,确定了反应器的最佳处理条件。对于氨氮质量浓度为50 mg/L、ρ(COD)为200 mg/L的原水,在温度为30℃、pH=8.0、ρ(DO)=2.0 mg/L的处理条件下,反应系统对氨氮和COD的处理效果最佳,去除率分别可达94.9%和85.7%。     

碱改性沸石吸附铅和氨氮性能及对稀土矿山土壤的修复作用

针对废弃离子型稀土矿山中的重金属铅和氨氮复合污染问题，本文采用木醋液、氢氧化钠、木醋液-氢氧化钠对天然沸石进行改性，利用扫描电镜(SEM)、比表面积测定(BET)、X射线衍射(XRD)分析改性前后沸石的微观结构和物相组成变化。开展室内模拟溶液中吸附动力实验；以现场采集的土壤为基质，进行柱淋滤实验及土壤中稳定化实验，分析了天然沸石和氯化钠、氢氧化钠、木醋液-氢氧化钠三种不同改性沸石对铅和氨氮的形态影响。结果表明：碱改性沸石和碱+木醋液改性沸石对200mg/L铅的去除率超过94%，对30mg/L氨氮的去除率大于65%;2%(质量百分比)为碱改性沸石的最佳添加比例，使土壤中铅有效态固化率达52%，氨氮由不稳定态向稳定态转化。现场中试实验证明，添加修复材料6个月后，碱改性沸石吸附稳定土壤中氨氮达94.61%。碱改性沸石不仅制备工艺简单，价格便宜，无二次污染，而且对土壤中铅和氨氮复合污染有很好的稳定化效果，可作为用于废弃稀土矿山土壤修复稳定化材料之一。     

活化沸石除铵及其动力学过程研究

对新型水处理材料活化沸石去除水中氨氮的各项性能进行了研究。单因素影响试验表明,沸石用量、粒径、溶液温度、浓度、pH值及吸附时间对去除效果有重要影响。据此确定了最佳静态试验条件,在该条件下,活化沸石对水中的氨氮有较好的去除效果,可将生活污水中的120 mg/L氨氮降到40 mg/L。动态小试确定了小试设备的工艺参数,该处理设备在实际运行过程中,吸附周期为64 h,处理效果良好。动力学研究表明,活化沸石除铵是离子交换与吸附两种行为共同作用的结果,该过程符合Freundlich等温式,动力学方程可用一级反应来描述。     

水力旋转填料生物接触氧化处理城市污水的研究

通过对中试规模的新型水力旋转填料生物接触氧化法处理城市污水的试验研究,利用新型填料的独特构型,增强反应器的传质性能,探讨了接触氧化池对COD、NH+4-N的去除,及水力停留时间、气水比、温度对处理效果的影响。试验结果表明在水力停留时间为2~2.5h,气水比为(7~8)∶1,进水COD、NH4+-N浓度分别为130.1~366.5mg/L、11.3~19.2mg/L的条件下,两者的平均去除率为75.9%、65.4%,出水COD、NH4+-N浓度均已达到国家二级排放标准;气水比和水力停留时间对接触氧化池处理效果的影响较为明显;低温下接触氧化池对有机物、氨氮的去除仍具有较好的效果。     

片沸石、钙基膨润土去除垃圾渗滤液中有害物质的实验研究

以位于北京昌平小汤山的阿苏卫垃圾卫生填埋场渗滤液为研究对象,在不同的环境条件下:酸度(pH=5~9),温度(4℃~30℃),利用片沸石、钙基膨润土去除垃圾渗滤液中有害物质的实验,以化学耗氧量(COD)、氨氮为评价指标,分别探讨片沸石、钙基膨润土的COD、氨氮去除效果与其用量、渗滤液pH、温度、振荡时间的关系。研究表明,在实验条件下,片沸石对COD的最大去除量约为31×10-3,对氨氮的最大去除量约为27×10-3;去除COD、氨氮的最佳条件分别为:片沸石用量20 g/L、pH为5、温度4℃、振荡时间100 min。在实验条件下,钙基膨润土对COD的最大去除量约为63×10-3,对氨氮的最大去除量约为14×10-3;去除COD、氨氮的最佳条件分别为:钙基膨润土用量30 g/L、pH为5、温度4℃、振荡时间100 min。根据实验结果,对片沸石、钙基膨润土去除COD、氨氮的机理主要是氢键、静电作用及离子交换作用。     

天然丝光沸石表面重构改性及其在水中去除重金属的应用

天然丝光沸石作为一种绿色廉价多孔材料广泛应用于环境治理中去除重金属,目前报道的天然沸石对重金属的去除率多在60%～90%,提升其去除效率已成为研究热点。本文采用正硅酸乙酯对天然丝光沸石进行表面重构改性,通过TEM、XRD、BET等手段表征其形貌和结构。结果表明:正硅酸乙酯水解生成的SiO_2可与天然丝光沸石复合形成新颖的"SiO_2/丝光沸石",原沸石表面包覆了新生纳米SiO_2孔结构,同时没有损坏原始沸石的多孔结构,使改性沸石材料兼具了天然丝光沸石和纳米SiO_2孔结构优点,增强了对重金属离子的吸附能力。该改性材料对水中Pb~(2+)、Cd~(2+)、Zn~(2+)和Mn~(2+)的最高吸附率为99. 3%、97. 1%、98. 3%和97. 0%,且极少解吸,性能稳定。考虑经济成本并保证合适吸附率的情况下选择吸附效率最佳的投加量,得到改性材料对初始浓度10 mg/L的Pb~(2+)、Cd~(2+)、Zn~(2+)、Mn~(2+)溶液的最佳投加量分别为0. 5 g/L、2 g/L、2 g/L、5 g/L,可为中试和规模应用提供参考。较之焙烧、酸、碱、盐和有机改性,本改性方式对多种重金属均有高的吸附率,并显现出操作简便、成本低和环境友好等优势,具有较好应用前景。     

沸石强化过滤的中试及生产性试验研究

对新型水处理材料沸石强化常规给水处理工艺进行了中试和生产性试验,并与石英砂滤料做了对比.中试结果表明粒径为0.80-1.20mm沸石对浊度、氨氮、有机物都表现出良好的去除效果,过滤时的水头损失、反冲洗强度明显小于石英砂,不仅能满足反冲洗要求,还可节省反冲洗水量,降低运行成本.在生产性试验条件下,沸石对浊度、氨氮、耗氧量的去除率分别为95%、83%和39%.因此,在当前水源水遭到污染的情况下,用沸石替代石英砂滤料可明显改善水质,在不增加处理构筑物的情况下,对给水处理工艺可起到强化作用     

天然沸石曝气生物滤柱脱氮性能及生物再生

对二级天然沸石曝气生物滤柱的脱氮性能和生物再生进行了实验研究.研究结果表明,在进水有机负荷0.8～6.4 kgCOD/(m3·d)、水力负荷1～2 m/h、气水比1:1～4:1的工艺条件下,COD、氨氮和总氮去除率分别达到67%～90%、52%～82%和33%～67%;水中氨氮含量在10～30mg/L时,硝化速率为0.23mg/min.生物再生过程中,微生物不仅硝化解吸氨氮,还可以深入沸石孔道,直接利用沸石吸附的氨氮.分级分段进水可以提高沸石生物再生速度,减少再生时间.     

牡蛎壳改性及联合释氧复合材料修复地下水氨氮污染实验研究

为研究以牡蛎壳-释氧复合材料为填料的渗透反应格栅去除地下水氨氮污染的效果及其经济实用性,开展了相关室内实验:采用高温加热方式对牡蛎壳进行改性,通过测定牡蛎壳改性后的比表面积判定其吸附效果;以过氧化钙为释氧化合物,将其与水泥、石英砂/牡蛎壳粒、钙基膨润土以一定比例混合制成粒径约1.8 cm球型释氧材料,采用静态实验研究不同原料配比的释氧材料的释氧性能;最后研究了两种不同粒径牡蛎壳粒-释氧复合材料修复地下水氨氮的效果及不同供氧方式下不同吸附材料修复地下水氨氮的效果及其经济实用性。结果表明:对牡蛎壳粒进行高温改性,牡蛎壳粒高温条件下会产生团聚现象,比表面积随煅烧温度升高呈下降趋势,高温改性方式并不能有效改善牡蛎壳粒吸附性能;实验中制作的释氧材料在95天的实验期间,各实验柱的溶解氧量可以保持在18 mg/L左右,且在嗜碱菌作用下pH值得以有效降低,所制作的释氧材料可为硝化细菌长期在溶解氧低的地下水环境中生长提供氧气;以牡蛎壳-释氧复合材料为填料的渗透反应格栅通过耐碱硝化细菌的硝化作用可以将氨氮浓度从50 mg/L降至约35 mg/L,不同粒径牡蛎壳粒修复效果差异不明显。使用牡蛎壳-释氧复合材料渗透反应格栅长期修复地下水氨氮,不仅可以达到活性炭及沸石作为骨架的修复效果,而且更加具有经济实用性。     

13X沸石分子筛对饮用水中NH_4~+-N吸附性能的实验研究

研究了 13X沸石分子筛对饮用水中低浓度NH+4 N的吸附性能 ,包括影响吸附的主要因素、沸石对NH+4 N的吸附效果、沸石的再生效果及沸石对NH+4 N的吸附机理。实验表明用NaOH处理的沸石比未处理的沸石对NH+4 N的吸附效果要好。在 pH值为 6 5～ 7 5、吸附时间为 2 0min、吸附温度为 2 0～ 30℃的条件下 ,沸石对NH+4 N的吸附率接近 10 0 % ,沸石对NH+4 N的吸附量可达 16 32mg/g。用直接焙烧法进行再生活化处理后的沸石对NH+4 N的吸附率仍接近 10 0 % ,沸石对NH+4 N的吸附机理是以离子交换吸附作用为主。 13X沸石吸附NH+4 N的过程符合Langmuir吸附等温模式。实验证明 ,利用 13X沸石净化含低浓度NH+4 N的饮用水具有良好的工业化应用前景。     

13X沸石分子筛对水中Hg2+吸附性能的实验研究

13X沸石分子筛吸附水中Hg2+的实验研究表明,13X沸石在pH值为5~6、时间为20 min、温度为20~30 ℃条件下对Hg2+ 的吸附效果最佳。在13X沸石的用量为4 g/L的条件下对原始浓度为0.2 ~100mg/L的Hg2+进行吸附,吸附量由0.035 6 mg/g增加到21.87 mg/g。13X沸石可使原始浓度为0.01 mg/L的Hg2+降至0.002 mg/L以下。饱和NaCl溶液对吸附Hg2+后的13X沸石解吸效果良好,解吸后的13X沸石循环使用4次,对Hg2+的吸附率仍未降低,表明13X沸石的重复利用效果良好。通过在洗脱Hg2+ 的解吸液中加入Na2S·9H2O,可使Hg2+形成HgS沉淀进行回收,回收率可达90%以上。实验表明,13X沸石适用于对水中低浓度Hg2+的深度净化处理。     

Indoor experiment and numerical simulation study of ammonia-nitrogen migration rules in soil column

The riverbank soil is a natural purifying agent for the polluted river water(Riverbank filtration, RBF). This is of great importance to groundwater safety along the riverbank. This paper examines the migration and transformation rules of ammonia-nitrogen in three typical types of sand soil using the indoor leaching experiment of soil column, and then makes comparison with the indoor experiment results in combination with the numerical simulation method. The experiment process shows that the change in ammonia-nitrogen concentration goes through three stages including "removal-water saturation-saturation". As the contents of clay particles in soil sample increase, the removal of ammonia-nitrogen from soil sample will take more time and gain higher ratio. During the removal period, the removal ratio of Column 1, Column 2 and Column 3 averages 68.8%(1-12 d), 74.6%(1-22 d) and 91.1%(1-26 d). The ammonia-nitrogen removal ratio shows no noticeable change as the depth of soil columns varies. But it is found that the ammonia-nitrogen removal ratio is the least of the whole experiment when the soil columns are at the depth of 15 cm. It can be preliminary inferred that the natural purifying performance of soil along the river for ammonia-nitrogen in river water mainly depends on the proportion of fine particles in soil. HYDRUS-1D model is used to simulate this experiment process, analyze the change of the bottom observation holes by time and depth in three columns(the tenth day), and make comparison with the experiment result. The coefficients of determination for fitting curves of Column 1, Column 2 and Column 3 are 0.953, 0.909, 0.882 and 0.955, 0.740, 0.980 separately. Besides, this paper examines the contribution of absorption, mineralization and nitrification in the simulation process. In the early removal stage, mineralization plays a dominant role and the maximum contribution rate of mineralization is 99%. As time goes by, absorption starts to function and gradually assumes a dominant position. In the middle and late removal stage, nitrification in Column 1 and Column 2 makes more contribution than mineralization. So the experiment result of the ammonia-nitrogen concentration is 0.6% and 2.4% lower than that in effluent and the maximum contribution ratio of nitrification is -4.53% and -5.10% respectively when only the function of absorption is considered. The mineralization in Column 1 and Column 2 in the middle and late removal stage still plays a more important role than nitrification. So the experiment result is 1.4% higher than that in effluent and the maximum contribution ratio of nitrification is -2.51% when only the function of absorption is considered. Therefore, absorption, mineralization and nitrification make different contributions during different part of the stage. This means that the natural purifying performance of soil along the river for ammonia-nitrogen in river water not only depends on the proportion of fine particles in soil, but depends on the mineralization and nitrification environment. This can offer some insights into the protection and recovery of groundwater along the riverbank.     

Removal of metal from acid mine drainage (AMD) by using natural zeolite of Nizarneshwar Hills of Western India

The mining industry faces stringent effluent discharge regulations and has acknowledged that it is necessary to look into innovative technologies to recycle considerable amount of effluent rather than discharging into surface water. Effluents from mines give rise to aesthetic unpleasantness. The focus of the investigations was to cope with more stringent effluent discharge regulations and to protect the ecosystem from harmful pollutants in the mine effluents. Copper is one of the heavy metal in the mine systems, which are known to be a harmful element. The present study has been undertaken to investigate a process that might remove Cu(II) from mine waste water by using natural zeolite, such as stilbite, and compared with synthetic resins like CSA-9 and CSA-609D. In this study, natural zeolite was used as a low-cost adsorbent to evaluate its ability to remove heavy metals from acid mine drainage. The zeolite used in this study is the natural clay mineral from the Nizarneshwar Hills of Western India. Three resins tested are CSA-9, natural zeolite–stilbite, and CSA-609D. Batch testing has been conducted to select effective ion-exchange resins for copper removal and to determine effective regenerants for regeneration of exhausted resins. All tests were conducted at bench scale and in batch mode. Three strong acid cation exchangers were evaluated to compare their metal removal capacities. The metal concentration in the effluent was reduced with all resins tested. It was found that, among all the three types of natural zeolite, stilbite shows the highest removal efficiency of copper in every parameter that is considered for evaluating the performance of resins.     

Removal of chromate from aqueous solution using treated natural zeolite

This paper present the possible alternative removal options for the development of safe drinking water supply in the chromium-affected areas. The Cr (VI) state is of particular concern because of its toxicity. The mordenite has suitable mineralogical properties that enable them to be used for ion-exchange processes. This includes total cation exchange capacity. However, in the present work, the modified-natural zeolite was used as an adsorbent for the removal of Cr (VI) from aqueous solution. The ability of modified natural zeolite (mordenite) to remove inorganic anion was investigated. Laboratory experiments were conducted examining the effect of the sorption of cationic surfactants. On the basis of the results of this study, the HDTMA-HSO₄ modified zeolite appears suitable as a sorbent for hexavalent chromium whereas EHDDMA-modified zeolite were not removed with the same efficiency. The sorption of chromate on HDTMA-zeolite results from a combination of entropic, coulombic, hydrophobic effects, and HDTMA counterion.     

天然沸石负载二氧化钛光催化剂的制备与性能研究

以钛酸丁酯为钛源，天然沸石为载体，用溶胶．凝胶法制备了天然沸石负载TiO2光催化剂，用紫外可见吸收光谱、比表面积、红外光谱和X射线衍射等分析技术对沸石负载TiO2光催化剂进行了表征，以甲基橙为目标降解染料，考察了TiO2负载量、催化剂用量、热处理温度等不同条件下催化剂的光催化活性，结果表明，用天然沸石为载体所制得的TiO2光催化剂对于甲基橙具有较好的光催化降解效果。     

Comparative study on adsorption of chromium(VI) from industrial wastewater onto nature-derived adsorbents (brown coal and zeolite)

The removal of hexavalent chromium from wastewater streams has received an considerable attention in recent years, since it can cause harmful effects on the environment. Several approaches, including adsorption, are recognized to tackle this problem, but unfortunately most of these processes are impressed with practical conditions of the experiments. The main objective of this study was to recognize applicable conditions for Cr(VI) removal from an industrial drainage using nature-derived adsorbents (brown coal and modified zeolite) and to make the process more adaptive by using adsorbents conjointly. Batch experiments were carried out by agitating Cr(VI) stock solution with adsorbents at room temperature. The influence of main operating parameters was explored, and the best proportion of the adsorbents was determined. Maximum sorption of Cr(VI) onto brown coal was observed at pH = 4 by adding 60 g L^?1 adsorbent to contaminated solution. In case of using zeolite, the modification process was required, and the pH indicated a weak influence in a wide range (2–8). Optimum dosage of modified zeolite for Cr(VI) removal was 10 g L^?1. The hybrid application of adsorbents with the mass ratio of brown coal/modified zeolite at (3:1) was capable of removing more than 99% of Cr(VI) from contaminated wastewater in the natural pH range of the wastewater. The adsorption of Cr(VI) by brown coal and modified zeolite followed Langmuir and Freundlich isotherm models, respectively. Sorption of Cr(VI) onto both brown coal and modified zeolite fitted well to pseudo-second-order rate reaction.     

松辽盆地周围沸石矿成矿构造动力学环境

松辽盆地周围沸石资源丰富 ,矿床类型多样 ,是中国东部环太平洋沸石成矿带的重要组成部分。研究区NE—NNE向深大断裂带控制着中生代火山岩和沸石矿带的空间展布 ,而不同方向深大断裂带的交接复合地段则决定了沸石矿田和主要矿床的空间定位。燕山中晚期以挤压-剪切 (左行 )为主的构造动力学机制控制了富碱高钾火山岩的发育 ,为沸石矿源岩的形成期 ;喜山期的构造反转以拉张 -剪切 (右行 )为主的构造动力学机制及其相伴的岩浆热事件 ,导致区域地热异常、地下流体增温和沸石矿化作用的快速进行。研究区中生代火山岩系中沸石矿床的主成矿期为喜山期 (6 4 5～ 5 5 0Ma)。