3种湿地填料对水体中氮磷的吸附特性研究

针对污染水体中氮磷超标问题,以海绵铁、沸石、砾石为填料,采用等温吸附、吸附动力学模型的方法开展3种湿地填料对氮磷吸附特性研究.结果表明:(1)填料对氮和磷的吸附均能用Langmuir和Freundlich方程描述.理论上对磷的吸附量依次为海绵铁＞沸石＞砾石;对氮依次为沸石＞海绵铁＞砾石.(2)双常数、一级动力学和Elovich方程动力学模型能够较好地描述填料对氮磷的等温吸附动力学特征,其中Elovich方程对3种填料的磷的吸附动力学特征描述更准确;一级动力学方程对沸石的氮的吸附动力学特征描述最精准.(3)填料对氮磷的吸附过程呈现先快后慢的整体趋势.从对氮磷的吸附量、吸附速率看,海绵铁和沸石能够作为人工湿地的填料对污水进行处理,并且经济方面较便宜,取用方便.     

复合垂直流人工湿地除磷正交试验研究

为了确定复合垂直流人工湿地的流程、水力负荷、pH、COD对TP去除率的影响和提高除磷效果,选择了美人蕉和风车草构建的复合垂直流人工湿地试验系统,开展除磷的正交试验研究。采用SPSS13.0软件对正交试验结果进行方差分析,确定各因素显著性及优选条件。结果表明,复合垂直流人工湿地流程、水力负荷、pH、COD对除磷效果均有影响,其中流程对TP去除率影响显著,COD对TP去除率影响不显著。各因素对TP去除率的影响程度依次为:流程水力负荷pHCOD。除磷优选条件:COD为225mg/L,pH为8,流程为1100mm,水力负荷为181.25L/(m2.d)。     

人工湿地基质对NH4＋-N吸附性能

为研究建筑废物红砖和工业废物煤渣用作人工湿地脱氮基质的可行性,分别通过静态吸附实验和动态NHf—N去除效果实验进行考察。结果表明,红砖和煤渣对NH4＋-N最大静态吸附量分别为0．2533mg／g和0．0533mg／g,其吸附等温曲线均符合Freundlich型吸附方程,吸附常数分别为0．0419和0．0091;红砖煤渣组合对污水中NH4＋-N平均动态脱除率达到41．18％,高于红砖的37．63％和煤渣的30．92％。     

3种不同基质潜流湿地对磷的去除效果

基质是潜流式人工湿地污水处理系统的重要组成部分，直接影响到系统的处理效果。本文研究了由沸石、页岩陶粒和碎石3种不同基质构建的潜流式人工湿地对磷的去除效果。结果表明，在设计水力停留时间3d，连续进出水情况下，碎石单元对磷的去除效果最好，页岩陶粒单元次之，沸石单元效果最差，平均去除率分别为95％、60％和35％。在潜流式人工湿地污水处理系统运行初期观察到磷释放现象，沸石单元最为明显。进水磷浓度较低时，磷的去除率随浓度升高而升高，当正磷、总磷浓度分别升高到2．4—2．5和3．1～3．3mg／L时，正磷、总磷的去除率开始迅速下降。     

污水处理中的人工湿地强化技术研究

人工湿地作为一种新型污水生态处理工艺受到越来越广泛的重视，在生活污水、特种工业废水、采矿污水、农业和畜牧业污水以及水产养殖废水等处理中得到了广泛的应用。但是其本身的局限却限制了它在高浓度废水、某些工业废水处理等方面的应用，在寒冷地区的应用也受到限制。本研究分析了一些强化技术（如湿地内部要素强化、工艺强化和工程强化等）在提高人工湿地的净化效能以及扩大其应用范围的可能性。     

模拟煤灰渣垂直潜流人工湿地的除磷性能分析

为确定煤灰渣作为垂直潜流人工湿地基质的可行性,通过静态吸附实验和煤灰渣去除生活污水中的磷素实验,表明煤灰渣对污水中磷素的吸附平衡时间较短,吸附速率较快.当温度降低时,煤灰渣的磷素吸附容量对吸附平衡浓度依赖性和吸附强度随之降低,最大理论吸附容量亦降低 83.10% .在处理0.5 m 3 /(m2·d)的生活污水中,煤灰渣对TP的平均去除率达86.03%,吸附方式包括物理吸附和化学吸附,同时得出煤灰渣最大磷素解析量占最大理论吸附容量的0.73%,在实际人工湿地应用中应注意磷素解析而形成的二次污染.     

8种植物床人工湿地脱氮除磷的研究

分别以水葫芦、西洋芹、空心菜、水芹、混合种(黄菖蒲、千屈菜、再力花)、千屈菜、再力花、黄菖蒲等植物床构建潜流人工湿地,研究其对生活污水氮、磷的净化功能及其去除率与水力停留时间(HRT)的变化规律。结果表明,各种植物床对TN、TP的去除率随HRT的延长而增加,不同植物床的脱氮除磷效果是不同的。千屈菜植物床对TN的去除效果最好,HRT为3d时,TN去除率为56%;HRT为6d时,TN去除率达77%。再力花植物床对TP的去除效果最好,HRT为3d时,TP去除率达78%;HRT为6d时,TP去除率达96%。其他植物床也有较好的脱氮除磷效果。各种植物床处理后出水TN、TP均较低,HRT为3d时,出水TN均低于《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级A标准规定的限值(15mg/L),出水TP均低于GB 18918—2002二级标准规定的限值(3mg/L);7种植物床构建的潜流人工湿地(水葫芦的数据丢失)对TN、TP的去除均满足一级反应动力学方程,且相关性显著。     

人工湿地数学模型模拟与应用

人工湿地生态系统具有投资低、出水水质好、抗冲击力强、增加绿地面积和操作简单等优点,在国外得到了较好应用.综述了人工湿地净化技术及湿地模型的研究进展,重点介绍了国外已经成功验证与应用的3种人工湿地模型的开发情况.同时应用某人工湿地的实测数据,通过对模型的验证和率定,表明模型在评估湿地功能和优化设计上的实用性.最后,对人工湿地模拟模型的应用前景及存在问题进行了评述.     

宽叶香蒲表面流人工湿地脱氮除磷效果研究

以运行A/O工艺的生化反应器出水为处理对象,在中试规模上研究了宽叶香蒲表面流人工湿地的脱氮除磷效果及影响因素.结果表明,在工况Ⅰ条件下,COD去除率为43.2%,COD面积负荷去除率为4.79 g/(m2·d),COD面积负荷去除率常数为0.18 m/d,SS、NH4+-N和NO-3-N的去除率分别为41.2%、9.4%、3.4%,TN去除率为11.8%,TN面积负荷去除率为1.36g/(m2·d),TN面积负荷去除率常数为0.04 m/d,TP去除率为30.1%,TP面积负荷去除率为0.29 g/(m2·d),TP面积负荷去除率常数为0.13 m/d;在工况Ⅱ条件下,COD去除率为18.7%,COD面积负荷去除率为1.19 g/(m2·d),COD面积负荷去除率常数为0.06 m/d,SS、NH4+-N、NO2--N、NO3--N的去除率分别为31.6%、29.8%、65.0%,29.2%.TN去除率为31.4%,TN面积负荷去除率为2.33 g/(m2·d),TN面积负荷去除率常数为0.12 m/d,TP去除率为29.4%,TP面积负荷去除率为0.22 g/(m2·d),TP面积负荷去除率常数为0.11 m/d.在COD面积负荷去除率,TN面积负荷去除率、TP面积负荷去除率分别为4.90～9.80、2.76～8.83、0.57～1.39 g/(m2·d),水力停留时间(HRT)为0.4～1.1 d条件下,随HRT,水温、(NO2+-N+NO3--N)/TN的增加,表面流人工湿地的TN面积负荷去除率线性增加.     

潜流、垂直流人工湿地污染物净化效果及耐污染负荷冲击能力研究

依托建立在新沂河河漫滩上的人工湿地中试工程进行现场试验,研究分析潜流和垂直流2种人工湿地对污染河水的净化效果及其耐污染负荷冲击能力。结果表明:在相同的进水高锰酸盐指数浓度条件下,垂直流对高锰酸盐指数的净化效果明显优于潜流;2种人工湿地对NH4+-N的去除率均比较高(平均去除率均高于80%),且没有明显差异;2种人工湿地构造不同引起的水流运行方式及截留、过滤作用的差异对高锰酸盐指数的去除影响较大,而对NH4+-N去除的影响较小;进水污染负荷变化对人工湿地污染物去除的影响显著,垂直流耐高锰酸盐指数污染负荷冲击能力明显强于潜流,而对NH4+-N污染负荷变化,两者都表现出了较强的耐受能力,差异不明显。     

芦苇人工湿地在环境保护中的应用

叙述了芦苇人工湿地污水处理技术的分类、特点及其在国内外的研究与应用进展。介绍了复合式芦苇湿地、新型芦苇床填料等相关的新技术，指出系统的堵塞和芦苇的衰退等问题是进一步发展芦苇湿地亟待解决的问题。     

Study of the effect of pyrite and alkali-modified rice husk substrates on enhancing nitrogen and phosphorus removals in constructed wetlands

Environmental Science and Pollution Research - The combined effects and respective advantages of using pyrite and alkali-modified rice husk (RH) were studied as substrates for nitrogen and...     

模拟垂直潜流人工湿地大气复氧规律研究

为优化湿地设计、改善湿地处理效果,初步探讨了水力负荷、非饱和区运行距离、平均孔隙率和温度对湿地大气复氧量(DO)的影响,构建了垂直潜流人工湿地大气复氧模型.结果表明,垂直潜流人工湿地大气复氧量与水力负荷(q)、温度(T)负相关,与非饱和区运行距离(h)、平均孔隙率(ε)正相关;以不同浸润面高度运行时,大气复氧量可用DO=-1.035q+38.078ε+0.043h-0.115T-9.630表述;以变浸润线运行时,大气复氧量可用非饱和区运行距离复氧量的加权积分平均值表述.实测结果率定表明,该模型表述垂直潜流人工湿地大气复氧量合理可行.     

人工湿地植物研究进展

人工湿地具有去除污染效果好、运行费用低和易维护等特点,已被广泛用于污水处理中.湿地植物在其中起着重要作用,主要包括直接吸收氮、磷等污染物,通过根系输氧促进根区的氧化还原反应与好氧微生物活动及增强和维持介质的水力传输等.综述了人工湿地植物的去污机理,阐述了湿地植物对生物可降解的有机物、营养性污染物和有毒有害物质净化的研究成果与应用,并展望今后进一步研究的重点.     

人工湿地污水处理系统中的植物氮磷吸收富集能力研究

比较研究了人工湿地污水处理系统中7种植物对氮、磷的吸收能力.研究表明,所选7种湿地植物,稳定生长4个月后,平均总生物量在1 215～3 500 g/m2,植物氮、磷平均质量浓度分别为13.76～23.11、1.44～3.80 mg/g.香蒲具有最高氮积累量达48.18 g/m2,梭鱼草具有最高磷积累量为7.23 g/m2,姜草对氮、磷的积累量最低分别为21.40、1.68 g/m2.植物地上部氮、磷积累量与地下部的氮、磷积累量差异较大,除姜草外,植物地上部、地下部的氮、磷积累量比均大于3,黄花美人蕉地上部、地下部的氮、磷积累量比分别达11.75、12.10.通过植物收割去除氮、磷量约占湿地总去除量的2%～6%.     

Establishment of a constructed wetland in extreme dryland

Background, aim, and scope

The project was set to construct an extensive wetland in the southernmost region of Israel at Kibbutz Neot Smadar (30°02′45″ N and 35°01′19″ E). The results of the first period of monitoring, summary, and perspectives are presented. The constructed wetland (CW) was built and the subsequent monitoring performed in the framework of the Southern Arava Sustainable Waste Management Plan, funded by the EU LIFE Fund. The specific aims were: (1) To end current sewage disposal and pollution of the ground, the aquifer, and the dry river bed (wadi) paths by biologically treating the sewage as part of the creation of a sustainable wetland ecosystem. (2) Serve as an example of CW in the Negev highlands and the Arava Valley climates for neighboring communities and as a test ground for plants and building methods appropriate to hyper arid climate. (3) Serve as an educational resource and tourist attraction for groups to learn about water reuse, recycling, local wildlife and migrating birds, including serving the heart of a planned Ecological–Educational Bird Park. This report is intended to allow others who are planning similar systems in hyper arid climates to learn from our experience.

Materials and methods

The project is located in an extreme arid desert with less than 40 mm of rain annually and temperature ranges of ?5°C to +42°C. The site receives 165–185 m³ of municipal and agricultural wastes daily, including cowshed and goat wastes and winery outflow.

Results

The CW establishment at Neot Smadar was completed in October 2006. For 8 months, clean water flowed through the system while the plants were taking root. In June 2007, the wetland was connected to the oxidation pond and full operation began. Because of seepage and evaporation, during the first several months, the water level was not high enough to allow free flow from one bed to the next. To bed A, the water was pumped periodically from the oxidation pond (Fig. 1) and from there flowed by gravitation through the rest of the system. The initial results of the monitoring are promising. In nearly all measurements, the system succeeded as expected to reduce levels of contaminants at least to the level acceptable for irrigating fruit trees and often to the level of unlimited irrigation. The introduction of the plants in the system and their physiological performance were evaluated and were found to correlate well to the quality of water in the various beds.

Discussion

It should be said at the outset that evaluation of the performance of a CW system is a long-term process. Thus, the main aim of this report is to present the problems, difficulties, preliminary results, and concepts concerned with the first stage of establishment of CW in an extremely dry region.

Conclusions

The CW system was designed to dispose of municipal and agricultural wastes in a way that not merely reduces pollution, but adds to environmental quality by creating accessible parkland for local residents and tourists. Several factors affected the performance of the system at the initial stages of operation: ecological balance between microbes and plants, big seasonal variations, seepage and evaporation reduced the flow in the initial operation of the system. Despite the initial difficulties, the quality of water coming out the system is acceptable for irrigation.

Recommendations and perspectives

The CW can function well under extreme dryland conditions. The oxidation pond was the major source of evaporation and bad odors. Therefore, alternatives to the oxidation pond are needed. Cost effectiveness of the system still has to be evaluated systematically.     

潜流-表面流复合人工湿地的河道水质净化效果

针对太湖流域的小河道水环境污染普遍较重的现状,结合潜流和表面流人工湿地系统技术的优点,设计并制作了阶梯式的复合人工湿地系统,前端采用潜流,后端采用表面流,试验区种植密度为25株/m2的茭草,研究其组合工艺对河道水质的净化效果,以期为河道人工湿地的设置提供技术参数。结果表明,复合人工湿地系统具有较强的污染物去除能力,HRT为3.4d时,7—12月对TN、TP、NH+4-N和高锰酸盐指数的平均去除率分别达到了64.3%、63.9%、74.6%、51.1%,较同期相同HRT下潜流人工湿地去除率分别提高了12.1、10.6、1.8、5.1百分点。其中,前端0.25距离分数的去除率占各自总去除率的74.5%～91.2%。     

聚合酶链反应-变性梯度凝胶电泳技术研究梯田式人工湿地微生物群落动态变化

采用聚合酶链反应(PCR)—变性梯度凝胶电泳(DGGE)技术对梯田式人工湿地(TTCW)和复合垂直流式人工湿地(IVCW)生活污水处理系统内的微生物群落结构的动态变化及其对生活污水处理效果的影响进行了对比研究。结果表明:(1)TTCW和IVCW对生活污水均具有较好处理效果,其COD去除率平均分别为76.2%和72.6%、TP去除率平均分别为90.7%和85.6%、NH4+-N去除率平均分别为65.2%和58.8%;TTCW增氧作用明显。(2)2种人工湿地内均存在丰富的微生物群落,并均存在共有的微生物种群;在湿地沿程不同位置均存在一定数量的优势种群。(3)TTCW强化了大气复氧能力,使得湿地内DO较相同深度的IVCW的高。TTCW具有较强的污染物去除能力,特别是具有高效的脱氮除磷能力。这种能力可能主要是TTCW中微生物群落结构的变化所致。     

Optimal regulation of N/P in horizontal sub-surface flow constructed wetland through quantitative phosphorus removal by steel slag fed

High concentration of nitrogen and phosphorus and imbalance of N/P can lead to the formation of water and the malignant proliferation of toxic microalgae. This study put forward the advanced nutrient removal with the regulation of effluent N/P as the core in order to restrain the eutrophication and growth of poisonous algae. According to the preliminary study and review, the optimal N/P for non-toxic green algae was 50:1. The horizontal sub-surface flow constructed wetland was filled with steel slag and ceramsite to achieve the regulation of effluent N/P. The results showed that steel slag had the stable P removal capacity when treating synthetic solution with low P concentration and the average removal rate for 1.5, 1.0, and 0.5 mg/L synthetic P solution was 2.98 ± 0.20 mg kg−1/h, 2.26 ± 0.15 mg kg−1/h, and 1.11 ± 0.10 mg kg−1/h, respectively. Combined with P removal rate and P removal task, the filling amount of steel slag along the SSFCW (sub-surface flow constructed wetland) was 3.22 kg, 4.24 kg, and 4.31 kg. In order to ensure the stability of dephosphorization of steel slag, the regeneration of P removal capacity was investigated by switching operation of two parallel SSFCW in 20 days for cycle. The N removal was limited for the deficiency of carbon source (COD (chemical oxygen demand)/TN = 3–4), and was stable at 18.5–31.9% which was less affected by temperature. Therefore, by controlling the process of quantitative P removal of steel slag, the effluent N/P in SSFCW can be stable at 40–60:1 in the whole year, so as to inhibit the malignant proliferation of toxic algae.     

人工河岸湿地对面源污染的处理效果研究

针对城市河道污染治理存在的主要问题,并考虑到华南地区河流水量、水质、水温季节性变化大的特点,构筑了人工河岸湿地试验系统,对该系统约13个月连续性运行进行了观测和研究。结果表明,平均水力负荷为15cm/d工况下,试验系统对高锰酸盐指数、SS、NH3-N、TN和TP的平均去除率分别为50%、60%、50%、35%和45%;系统对高锰酸盐指数、NH3-N和TN的去除效果随季节变化明显,夏季处理效果好于冬季;SS处理效果受季节影响不明显;TP初期处理效果好于末期。该人工河岸湿地既能较好地改善水质,又能改善生态环境、美化城市景观,是一项适合城市河道污染治理的技术。