水陆交错带芦苇根孔及其净化污水的初步研究

芦苇是我国北方地区水陆交错带区域典型的湿地植物。在白洋淀水陆交错带湿地进行的试验结果表明，芦苇具有庞大的地下根状茎，形成芦苇根孔。根孔以横向走向为主，大多数芦苇根孔集中在18～75cm之间。与退化芦苇湿地相比，健康芦苇湿地苇高、苇粗，根、茎长而重。室内芦苇和小麦原状土柱(0～100cm)的污水净化实验结果表明，苇地土柱的净化能力大于麦地土柱，以对磷的净化最大。苇地土柱的净化率为TP92．6％、TN43．5％、COD54．1％，麦地土柱的净化率为TP86．0％、TN41．3％、COD29．8％。     

水陆交错带芦苇根孔及其净化污水的初步研究

芦苇是我国北方地区水陆交错带区域典型的湿地植物。在白洋淀水陆交错带湿地进行的试验结果表明,芦苇具有庞大的地下根状茎,形成芦苇根孔。根孔以横向走向为主,大多数芦苇根孔集中在18～75cm之间。与退化芦苇湿地相比,健康芦苇湿地苇高、苇粗,根、茎长而重。室内芦苇和小麦原状土柱(0～100cm)的污水净化实验结果表明,苇地土柱的净化能力大于麦地土柱,以对磷的净化最大。苇地土柱的净化率为TP92.6%、TN43.5%、COD54.1%,麦地土柱的净化率为TP86.0%、TN41.3%、COD29.8%。     

动态法研究芦苇湿地土壤对苯酚的净化能力及其影响因素

用动态土柱法研究芦苇湿地土壤对苯酚的净化效果及其影响因素。结果表明，同原状生长芦苇土柱、原状不生长芦苇土柱相比，模拟土柱对高、中、低三个浓度的苯酚均具有较好的净化效果，且对低浓度苯酚的净化效果最好；芦苇可以通过改变根际和非根际土壤性质以及溶液在土壤中的滞留时间，从而影响湿地土壤对苯酚的净化能力。     

人工湿地净化大连地区污染河水的试验研究

为研究人工湿地对大连地区污染河水的净化效果,以大连复州河为例,实验构建了不同基质和不同植物的人工湿地.系统稳定运行两年时间,实验结果表明,作为人工湿地基质,砾石对SS、TP的去除效果强于碎石,碎石和砾石对COD、TN、NH3-N去除效果相差不大;作为人工湿地植物,芦苇对SS、TP的去除效果强于黄菖蒲,黄菖蒲对TN、NH3-N的去除效果强于芦苇,两者对COD去除效果相差不大;温度对人工湿地的COD、TN、NH3-N去除率影响较大,对TP去除率影响较小.     

垂直—水平流人工湿地系统除污效果研究

以武汉汉阳桃花岛城市面源污染控制示范工程为依托，研究示范工程中垂直—水平流人工湿地系统对生活污水的净化效果。结果表明，在人工湿地水力停留3 d的情况下，垂直—水平流人工湿系统对COD、SS、TP和TN均具有明显去除效果。其中，对COD、SS的去除率主要位于垂直流阶段，对TP和TN的去除率主要位于水平流阶段。水平流湿地中，种植黄花美人蕉的湿地单元对COD、TP和TN处理效果略高于种植鸢尾和红花美人蕉的湿地单元。     

人工湿地对化粪池出水净化效果的研究

通过在同种基质上种植相同数目的芦苇,研究了垂直流人工湿地对化粪池出水的净化效果以及不同水力停留时间对污水净化效果的影响。结果表明,同种填料、不同水力停留时间对污水中TP、NH3-N、COD的净化效果不同。由于芦苇根系和微生物的吸收与分解作用以及基质的吸附作用,种植芦苇的人工湿地的出水水质要比没种芦苇的好。     

不同植物配置人工湿地冬季生活污水净化效果比较

以某三级串联水平潜流人工湿地污水处理工程为实验基地,研究了5种华南地区常见湿地植物的选择和配置对净化冬季生活污水的影响,为华南地区人工湿地合理优化配置植物提供一定的依据。结果表明:人工湿地系统在冬季对COD、BOD5、TP和大肠菌群仍有较好的去除效果,对TN的去除效果较差。在实验条件下,COD和BOD5的降解主要发生在第一级湿地单元,TP和TN的降解主要发生在第三级湿地单元。三级串联湿地系统净化效果较佳的植物搭配是:第一级栽种水生美人蕉,第二级栽种再力花,第三级栽种菖蒲。     

湿地植物对城市雨水径流污染的净化效能与适应性研究

通过灯芯草、千屈菜、菖蒲、梭鱼草的雨水径流水培试验,研究了湿地植物对城市径流主要污染物COD、TN、TP及重金属的净化效能,分析了植物对径流污染物的耐受性和适应性。结果表明:植物对重金属的净化效能良好;千屈菜对COD的耐受性及去除率差,当COD≥1 160 mg/L会导致其死亡;灯芯草对pH值的适应力差,酸雨会严重影响其水处理效果及长势;当pH<6时菖蒲和梭鱼草对径流TP的处理能力相当;对TN<20 mg/L的雨水径流,菖蒲对TN的去除效率达93%以上优于梭鱼草,且菖蒲对径流COD的去除效果及适应性好于其他三种植物,是较适宜的雨水径流湿地植物。     

不同生态修复措施对河道水质净化效果的影响试验研究

为研究不同生态措施对河道水质净化的效果,本文通过生态河道、人工湿地以及生态池三种修复措施对山东乐陵漳卫新河水质净化前后的效果进行了对比试验分析。结果表明:生态池去除TP效果最佳,而人工湿地则对COD和TN的去除效果最佳;生态池和人工湿地对水力负荷变化的适应能力较强,去除率与水力负荷的相关性不大;综合修复系统、人工湿地以及生态池的出口,COD和TP浓度与污染负荷呈正相关,TN的浓度则与污染负荷无明显关系。研究结果可为当地河道的生态治理工作提供借鉴。     

芦苇不同部位作为碳源对人工湿地脱氮除磷效果的影响

针对人工湿地中有机碳源不足造成脱氮效率较差的问题,寻找更高效的植物碳源以改善人工湿地内部碳氮比低的状况。通过试验比较芦苇穗(芦穗)、芦苇茎(芦茎)和芦苇根(芦根)3个部位在不同预处理方式下的静态释放规律,筛选出最佳的植物碳源,并通过小试人工湿地试验分析其作为植物碳源对脱氮效果的影响。分析结果表明:碱热处理能够提高COD释放量,相较其它预处理方式,其最大COD释放浓度提高10%,并提前释放一部分氮类化合物和含磷化合物;芦穗碱热处理初期COD释放量达到各部位中的最高值182.00 mg/L;从144 h内的平均TN释放量来看,芦穗碱热处理(6.16 mg/L)＞芦根碱热处理(4.21 mg/L)＞芦茎碱热处理(2.99 mg/L),芦茎释放量最少,比芦穗少一半以上;经过碱泡、碱热处理后,TN、TP、NH⁺₄-N、NO^-₃-N和NO^-₂-N释放量均小于简单处理。碱热处理后的芦苇茎是最佳植物碳源,具有较强的持续释碳能力,并且对氮、磷积累的影响最小;在小试人工湿地系统中添加碱热处理后的芦茎在不显著提高系统出水COD前提下,显著提高了TN和TP的去除率,相对对照组分别提高了61.14%和32.53%,达到同步强化脱氮除磷的效果。     

板间距对电絮凝处理微污染水的影响

电絮凝作为一种具有广泛应用前景的低廉高效污水处理技术,已经被证明在工业废水、生活污水等污染严重的水体处理上具有显著效果,但是目前对于电絮凝净化微污染水的相关研究较少。通过对电絮凝分批处理河水的实验研究,分析电絮凝方法处理微污染水的可行性,讨论极板间距的改变对电絮凝处理效果的影响。结果表明,电絮凝处理技术可以用于微污染水净化中,在电流密度为17.75 A/m2、极板间距为1.5 cm的条件下,反应30 min时,色度去除率为73.76%,浊度去除率为76.00%,悬浮固体去除率为85.71%,化学需氧量去除率为42.86%,总磷去除率为61.36%。在电絮凝反应中,极板间距对于微污染水的色度、浊度、悬浮固体和总磷去除效果具有明显的影响。     

Evaluation of bipolar electrocoagulation applied to biofiltration for phosphorus removal.

To reduce the residual organic matter and phosphorus contained in secondary effluent, a biofiltration system combined with electrocoagulation using bipolar iron electrodes was evaluated as a supplementary treatment to existing small-community sewage treatment. Based on the results of batch tests, bipolar electrocoagulation (BEC) was found to be more effective on phosphorus removal than monopolar electrocoagulation (MEC) but energy consumption was less in monopolar electrocoagulation. Optimum conditions of BEC to treat the secondary effluent were current density 15 A/m2, electrode spacing 1 cm and pH < 8. The removals of COD(Cr) and phosphorus by biofiltration system without BEC were 69.1% and 9.6%, respectively. However, biofiltration system combined with BEC showed 76.6-83.7% and 70.7-93.0% removal for COD(Cr) and phosphorus respectively. Extraordinary increase in phosphorus could be achieved by introducing electrocoagulation to biofiltration, and BEC/biofiltration system was evaluated to be applicable to existing small-community sewage treatment plants as a supplementary process.     

基于生态浮床的乡村微污染河道水质净化研究

为了综合解决乡村河流微污染问题,文章以上夹河退水渠河道微污染水体为对象,以净化能力强且观赏性较好的9种水生植物为试验供试植物,构建了单一植物型生态浮床,研究了植物型生态浮床对水体中氨氮(NH4^+-N)、总磷(TP)、化学需氧量(COD)等指标的去除情况,结果表明:9种植物生态浮床对乡村微污染河道水体中污染物的去除率有一定差异;其中,象草、芦苇、水葫芦对NH4^+-N去除率较高,分别为54.58%、61.04%、67.50%;黄菖蒲、美人蕉、水葫芦对TP去除率较高,分别为83.93%、86.26%、89.17%;黄菖蒲、风车草、水葫芦对COD去除率较高,分别为31.82%、31.83%、33.39%;该研究能够为植物型生态浮床技术在今后乡村微污染河流中的应用提供理论指导。     

Anaerobic reactor/high rate pond combined technology for sewage treatment in the Mediterranean area.

Two high-rate, anaerobic/aerobic units were used to treat the sewage of the Institut Agronomique st Vétérinaire Hassan II (Morocco) campus in a 1,100 m2-plant designed for 1,500 e.p. and receiving 63 m3 per day. The anaerobic pre-treatment consisted of a two-step up-flow anaerobic reactor (TSUAR) comprising two reactors and one external settler all in series. The aerobic line, or post-treatment, consisted of a high-rate algal pond (HRAP) and one maturation pond in series. The system totalized a hydraulic retention time (HRT) of 9 days. A gravel filter (GF) was constructed behind the TSUAR to trap low-density particles. The TSUAR removed 80% of COD and 90% of SS within 48 h. Solids retention time in the reactors averaged 32 d with a specific sludge production of 0.28 g SS g(-1) COD removed. Almost 93% of the sludge evacuated from the settler was stabilized. Specific biogas production from both reactors was 0.25m3 kg(-1) COD removed. Used in this configuration, the HRAP lost its BOD removal activity and increased its nutrients and pathogens removal capabilities (tertiary treatment). Results showed that 85% of total nitrogen and 48% of total phosphorus were removed by the HRAP. Land area requirement of this combination was less than 1 m2 per capita and filtered final effluent was of excellent quality (COD, 82 mg/l; TKN, 8.3 mg/l; total P, 2.7 mg/l, faecal coliforms, 2.4 10(3)/100 ml and zero helminths eggs).     

Vertical flow constructed wetlands for municipal wastewater and septage treatment in French rural area.

This paper presents the purification performance of 20 wastewater treatment plants with vertical reed bed filters (Macrophyltres), built between 1998 and 2003 by SAS Voisin, for communities of between 150 and 1400 PE. The first stage vertical reed bed (directly fed with raw wastewater by intermittent feeding) achieved high removal of SS, BOD and COD (mean respectively 96%, 98%, 92%). The second stage permitted compliance easily with effluent standards (SS < 15 mg/l, BOD < 15 mg/l, COD < 90 mg/l and mean TKN < 10 mg/l). Performance was not significantly influenced by variations of organic and hydraulic load, nor by seasonal variations. Rigorous operation and maintenance were required to obtain optimal performances. Another application of vertical reed beds is the treatment of septage (sludge from individual septic tanks). The results obtained on two sites operating for 2 and 3 years are presented. The first site achieved complete treatment of septage (solid and liquid fraction), the second permitted a pre-treatment for co-treatment of percolate with wastewater.     

Low-temperature post-treatment of anaerobically treated-sewage in anaerobic filter with cationic-polymer addition.

The post-treatment of domestic sewage pretreated in a 6 m3 UASB was investigated in two high-rate anaerobic filter (AF) reactors operated in parallel. The difference between the two AF reactors was only the addition of cationic polymer to the second reactor (AF + P). The reactors were operated at low temperatures, ranged between 13 and 20 degrees C. The media in each AF reactor consisted of vertical sheets of reticulated-polyurethane foam (RPF) with knobs. The results demonstrated that the AF + P reactor (HRT = 3 h) with cationic polymer addition (2 mg/L) was an efficient system for post-treatment. The removal efficiencies for total, suspended, colloidal and dissolved COD were, respectively, 41, 86 and 76 and 12% in the AF + P reactor and they were, respectively, 80, 97, 77 and 66% in the UASB + (AF + P) system. The removal of total, suspended and colloidal COD in the UASB + (AF + P) system were significantly higher than those achieved in the UASB + AF system. As hardly any nutrient was removed in the UASB + (AF + P) system, the effluent after pathogen removal is a valuable product for irrigation and fertilisation to close the water and nutrients cycle.     

Simultaneous sewage treatment and electricity generation in membrane-less microbial fuel cell

Long term performance of mediator-less and membrane-less microbial fuel cell (ML-MFC) was evaluated for treatment of synthetic and actual sewage and electricity harvesting. The anode chamber of ML-MFC was inoculated with pre-heated mixed anaerobic sludge collected from a septic tank. The ML-MFC was operated by feeding synthetic wastewater for first 244 days, under different organic loading rates, and later with actual sewage for next 30 days. Maximum chemical oxygen demand (COD) removal efficiency of 91.4% and 82.7% was achieved while treating synthetic wastewater and actual sewage, respectively. Maximum current of 0.33 mA and 0.17 mA was produced during synthetic and actual sewage treatment, respectively. Maximum power density of 6.73 mW/m(2) (13.65 mW/m(3)) and maximum current density of 70.74 mA/m(2) was obtained in this membrane-less MFC with successful organic matter removal from wastewater.     

Phosphorus removal under anoxic conditions in a continuous-flow A2N two-sludge process.

The Anaerobic-Anoxic/Nitrification (A2N) system is a continuous-flow, two-sludge process in which Poly-P bacteria are capable of taking up phosphate under anoxic conditions using nitrate as an electron acceptor. The process is very efficient because it maximizes the utilization of organic substrate for phosphorus and nitrogen removal. An experimental lab-scale A2N system fed with domestic sewage was tested over a period of 260 days. The purpose of the experiment was to examine phosphorus removal capacity of a modified A2N two-sludge system. Factors affecting phosphorus and nitrogen removal by the A2N system were investigated. These factors were the influent COD/TN ratio, Sludge Retention Time (SRT), Bypass Sludge Flow rate (BSF) and Return Sludge Flow rate (RSF). Results indicated that optimum conditions for phosphorus and nitrogen removal were the influent COD/TN ratio around 6.49, the SRT of 14 days, and the BSF and RSF were fixed at about 26-33% of influent flow rate.     

Enhanced biological phosphorus removal in RBC with SBR modification.

The rotating biological contactor (RBC) system was operationally modified with a sequencing batch reactor to achieve biological phosphorus removal from a weak domestic sewage along with nitrogen removal. This study utilized three RBC units, of which two units were the main units to remove phosphorus and NH4N and the third RBC unit was used as the storage of wastewater for its minimal effect to the PAO activities in the anaerobic stage during the operation. It was noticed that the biofilm thickness in RBC must be controlled to be less than 1.8 mm in order to achieve more than 70% of P removal with about 60% of N removal. With a settled sewage representing 200 mg/L of COD and 5 mg/L of P, the predicted P content in biofilm was more than 3% and the effluent P concentration was about 1 mg/L. The %P content in biofilm decreased with an increase of influent COD/TP ratios. The COD requirement for anaerobic P release was similar to reported values for the suspended growth system, however, the overall requirement increased with thicker biofilm.