生物接触氧化/垂直流人工湿地处理城市生活污水

采用生物接触氧化和复合垂直流人工湿地的组合工艺处理城市生活污水,考察了对主要污染指标的去除效果.结果表明:与不曝气和连续曝气相比,在间歇曝气条件下,组合工艺对COD和氮的去除率较高.在进水负荷为0.8m3/(m2·d)、水力停留时间为1d、曝气量为4.038m3/(m2·d)、曝气/停曝周期为20 min/60 min的条件下,组合工艺对COD、NH4+-N、TN的去除率分别为80.37％、98.32％、80.22％,出水COD、NH4+-N、TN浓度均达到了《城镇污水处理厂污染物排放标准》(GB 18918-2002)的一级A标准.     

脉冲垂直流人工湿地处理污染河水的试验研究

将脉冲布水引入垂直流人工湿地,考察了其与普通垂直流人工湿地对受污染河水处理效果的差异。结果表明,在水力负荷为0.6 m3/(m2.d)下,脉冲布水明显提高了人工湿地系统的复氧效果,普通垂直流人工湿地一级出水DO为零,而脉冲垂直流人工湿地一级出水DO平均为0.5 mg/L;两者对COD和TP的去除效果相当,脉冲和普通垂直流人工湿地对COD的去除率分别为59.2%和58.4%,对TP的去除率分别为83.6%和83.4%;但脉冲垂直流人工湿地对NH3-N和TN的去除效果优于普通垂直流人工湿地,脉冲垂直流人工湿地及其第一级湿地对NH3-N的去除率分别为38%和30%,对TN的去除率分别为40%和26.3%,而普通垂直流人工湿地及其第一级湿地对NH3-N的去除率分别为31.6%和22.1%,对TN的去除率分别为33.2%和23.9%。     

组合式接触氧化处理污染河水的研究

为了解组合式接触氧化工艺的特性,考察了组合式接触氧化对污染河水的净化效果.通过试验研究发现,在进水水质COD为29.57～56.45 mg/L,TN为0.97～4.29 mg/L,TP为0.15～0.35 ms/L情况下,此组合工艺对COD、TN和TP的平均去除率分别为52.54%、26.58%和22.85%.出水水质符合国家城镇污水处理厂污染物排放标准,污染河水得到了有效的处理.     

砾间接触氧化/水平潜流人工湿地净化微污染河道水

以微污染河道水为处理对象,研究了砾间接触氧化/水平潜流人工湿地复合工艺对水质的净化效果。经过26 d改变进水配比、曝气方式等的调控运行,成功启动复合工艺模拟装置,砾间接触氧化区(简称砾石区)的COD、NH4⁺-N去除率均稳定在75%左右,TN去除率在45%~60%。为进一步强化净化效果,探讨了砾石区水力停留时间(HRT)和砾石曝气区与非曝气区(O/A)分段进水配比对砾石区及后置潜流人工湿地出水水质的影响。当砾石区HRT为5 h时,砾石区对污染物的去除效果较好,COD、NH4⁺-N、TN平均去除率分别可达72%左右、75.28%、67.79%,人工湿地对三者的去除率分别为31%、43%、28%;当O/A区分段进水配比为1∶1时,对COD、NH4⁺-N的平均去除率较高,分别为77.39%和84.91%,分段进水配比为1∶2时,对TN的去除率最高,达到68.5%,人工湿地对TN的去除率为24.47%。因此,砾石区HRT为5 h为较佳参数,分段进水配比可根据进水污染状况灵活选择,研究结果可为实际工程应用提供理论支撑。     

接触氧化+人工湿地处理小区污水的试验研究

介绍了采用"接触氧化 人工湿地"组合工艺处理小区污水的试验研究。组合工艺的试验运行分两个阶段:前阶段生物接触氧化池连续运行,后阶段生物接触氧化池间歇运行。试验结果表明,间歇运行的生物接触氧化池与人工湿地组合,其运行效果优与连续运行的工艺组合。组合工艺的最佳运行工况为曝气强度为4.0 m3/(m2.h),进水0.25 h,曝气2 h,沉淀1 h,排水0.25 h,此时出水水质可达到《城镇污水处理厂污染物排放标准》(GB18918-2002)的一级A标准,经过消毒后可以回用。同时针对不同浓度的小区污水,还可以通过调整组合工艺的运行方式以满足排放标准要求。     

芦竹潜流人工湿地对微污染河水的净化效果

在野外构建芦竹水平潜流人工湿地,考察其对西南山地地区小城镇微污染河水的净化效果。结果表明,在进水流量为0.75 m3/d、HRT为2 d的条件下,芦竹人工湿地对河水有较好的净化效果,对CODMn、TN、NH4+-N及TP的平均去除率分别为34.1%、63.5%、73.4%、70.7%,而空白人工湿地的平均去除率仅为22.2%、32.7%、52.2%、36.6%,说明芦竹的存在促进了人工湿地对微污染河水的净化效果。     

垂直流人工湿地组合工艺在绿色建筑中的应用

在某房地产公司深圳总部绿色建筑工程中,采用水解酸化/垂直流人工湿地组合工艺处理优质杂排水,采用接触氧化/反硝化沉淀/垂直流人工湿地处理生活污水,对实际设计参数、水质监测数据进行分析可知,垂直流人工湿地组合工艺对污染物的总体去除率较高,出水水质完全能满足回用要求.垂直流人工湿地组合工艺完全可满足绿色建筑对节约水资源、保护环境、减少污染的要求.     

不同构型湿地氧分布及脱氮效果对比

通过2组对比试验(垂直流与水平流湿地、单段式与三段式水平流湿地), 考察了不同构型湿地中溶解氧的分布情况及脱氮效果。结果表明: 不同构型人工湿地水力流态的区别,导致了床体溶解氧分布和脱氮效果的差异。垂直流人工湿地独特的结构设计和水力流态更有利于湿地内部的供氧, 局部氧浓度可比水平流湿地高0.17 mg/L;脱氮效果优于相同运行条件下的水平流湿地, NH+4-N、TN去除率分别可提高约9%、5%。三段式水平流湿地通过接触槽内复氧, 有效改善了溶解氧分布, 利于硝化反应进行, NH+4-N去除率最高达66%, TN去除率最高达71%, 分别比单段式湿地提高约8%和5%。此外,三段式湿地在较低水位下运行仍能取得较好的脱氮效果,其最佳停留时间的范围也得以延展。     

生物、生态组合技术处理农村生活污水研究

采用厌氧/跌水充氧接触氧化/水生蔬菜型人工湿地组合工艺处理农村生活污水,考察了工艺的运行效果及各处理单元对去除污染物的贡献率.试验结果表明,该组合工艺对污染物具有较好的去除效果,且处理效果很稳定,其对COD、NH4+-N、TN、TP的去除率分别为68.15%、68.15%、69.50%、86.30%.跌水充氧接触氧化池对去除TN、TP的贡献率较小,对去除COD的贡献率相对较大;人工湿地对去除TN、TP的贡献率较大,对去除COD的贡献率相对较小.跌水充氧接触氧化与人工湿地相结合可以发挥两者的优势,并提高出水水质和系统运行的稳定性.     

曝气生态浮床/PRB组合工艺净化重污染河水研究

通过中试考察了曝气生态浮床/可渗滤反应墙(EAFB-PRB)组合工艺对重污染河水的净化效果.结果表明:组合工艺对COD、TN、NH_4~+-N和TP都有较好的去除效果,平均去除率分别为79.5%、27.9%、36.8%和87.0%;经处理后,水体的平均DO浓度由0.09 mg/L提高到1.7mg/L;对TSS的平均去除率达95.4%,出水清澈透明,感官效果好.可见,该组合工艺是改善重污染河水水质的有效方法.     

The effect of operating conditions on aquatic worms eating waste sludge

Several techniques are available for dealing with the waste sludge produced in biological waste water treatment. A biological approach uses aquatic worms to consume and partially digest the waste sludge. In our concept for a worm reactor, the worms (Lumbriculus variegatus) are immobilised in a carrier material. For correct sizing and operation of such a worm reactor, the effect of changes in dissolved oxygen (DO) concentration, ammonia concentration, temperature and light exposure were studied in sequencing batch experiments. DO concentration had an effect on both sludge consumption rate and sludge reduction efficiency. Sludge consumption rate was four times higher at DO concentrations above 8.1 mg/L, when compared to DO concentrations below 2.5 mg/L. Sludge reduction was 36 and 77% at these respective DO concentrations. The effect is most likely the result of a difference in gut residence time. An increase in unionised ammonia concentration drastically decreased the consumption rate. Ammonia is released by the worms at a rate of 0.02 mg N/mg TSS digested; therefore, replacing the effluent in the worm reactor is required to maintain a low ammonia concentration. The highest sludge consumption rates were measured at a temperature around 15 °C, whilst the highest TSS reduction was achieved at 10 °C. Not exposing the worms to light did not affect consumption or digestion rates. High temperatures (above 25 °C) as well as low DO concentrations (below 1 mg/L) in the worm reactor should be avoided as these lead to significant decreases in the number of worms. The main challenges for applying the worm reactor at a larger scale are the supply of oxygen to the worms and maintaining a low ammonia concentration in the worm reactor. Applying a worm reactor at a waste water treatment plant was estimated to increase the oxygen consumption and the ammonia load by 15-20% and 5% respectively.     

Performance of a sub-surface flow constructed wetland in polishing pre-treated wastewater-a tropical case study

This paper reports on the performance of three units of a sub-surface horizontal flow constructed wetland (CW) pilot plant in polishing effluent from the upflow anaerobic sludge blanket (UASB) reactor plant. Studies on the use of UASB for on-site wastewater pre-treatment were initiated in Tanzania for the first time in 1993, while initial research works on the application of CW for polishing effluent from UASB, the results of which are reported in this paper began in 1999. In this study the UASB reactor plant received and pre-treated part of the wastewater from the student's hostels at the University College of Lands and Architectural Studies in Tanzania. Out of the three units, unit B was planted with Phragmites mauritianus, unit C with Typha latifolia and A was used as a control. Both P.mauritianus and T.latifolia have been extensively researched in Europe and USA as suitable species of vegetation in CW. However, very limited studies on the suitability of these wetland plants have been reported under tropical climate. The studied parameters were chemical oxygen demand (COD), nitrate (NO(3)-N), nitrite (NO(2)-N), ammonium (NH(4)-N), faecal coliforms (FC), total coliforms (TC), pH, temperature and dissolved oxygen (DO). The study was carried out at an average hydraulic retention time of 1.93 days (1.85 in unit A, 1.96 in unit B and 1.99 in unit C) obtained as a ratio of the volume of wastewater in the wetland and the volumetric flow rate of wastewater through the wetland unit while taking into consideration the porosity of the media. Better performance for the vegetated units B and C were obtained compared to the control unit A. Nutrients were least removed in all units (NH(4)-N 11.2%, 25.2% and 23% in units A, B and C, respectively, NO(3)-N 32.2%, 40.3% and 44.3% for units A, B and C, respectively, and NO(2)-N 23.9%, 38.5% and 23.1% for units A, B and C, respectively). The COD removal rate was 33.6%, 56.3% and 60.7% for units A, B and C, respectively. The study also indicated that pH increased from the influent to the effluent and that DO increase was related to the decrease of temperature. FC and TC removal ranged from 43% to 72%, with the least removal in unit A.     

厌氧/跌水充氧接触氧化/人工湿地处理农村污水

为了使太湖地区农村污水处理达到占地面积小、除磷脱氮效率高、管理简单、运行和建设费用低的目标，采用厌氧／跌水充氧接触氧化／人工湿地组合工艺进行了工程规模的试验研究。结果表明，在厌氧池水力停留时间为2d、5级跌水充氧接触氧化池总水力停留时间为2h、并采用50cm／d的高水力负荷人工湿地的条件下，该组合工艺对COD和TN的平均去除率分别为81％和83％，对TP的平均去除率在进水TP〉1．5mg／L时达82％，在进水TP〈1．5mg／L时为72％。     

无阀垂直流湿地的冬季运行效果分析

垂直流湿地具有占地面积小、投资少、除污效率高等特点,但运行管理较复杂.为简化其管理,设计了一个无阀垂直流湿地小试系统,介绍了其构造,并模拟农村生活污水的排放规律在冬季进行了污水处理试验.结果表明：当水力负荷为8.5 cm/d时,黑麦草无阀垂直流湿地对有机物具有良好的去除效果,对COD的去除率达85%,出水COD＜50 mg/L;该湿地对TN的去除效果稳定,去除率为50%左右;对TP的去除率为93.5%～54.2%,并随运行时间的延长而下降.     

COD and nitrogen removal by biofilms growing on gas permeable membranes

A bioreactor was constructed and used to treat a synthetic wastewater containing ammonium acetate and trace nutrients for about 190 days. The reactor was aerated by means of bundles of gas-permeable hollow-fiber membranes that were installed in the reactor. The membranes provided a specific surface area of 422 m(2)/m(3) and the external surface of the membranes rapidly became covered in an active biofilm. The membrane bundles were agitated by an internal gas recycle. The gas bubbles in the water encouraged fiber-fiber contact and were intended to control biofilm growth. Chemical oxygen demand (COD) removals in excess of 95% were achieved in a 6h nominal detention time. Nitrification developed rapidly and complete oxidation of the influent ammonium was evident within 20 days. Even though the reactor was equipped with a large membrane surface area, the oxygen was consumed within the biofilm growing on the membrane surface. As a result, the external dissolved oxygen (DO) dropped to zero and the reactor was able to support essentially complete denitrification. After about 3 months of operation the reactor showed excellent removals of both COD and inorganic nitrogen but the performance could not be sustained. Excess biofilm accumulation eventually contributed to a deterioration in process performance. This study demonstrates that while membrane aeration can provide simultaneous BOD and N removal in the same reactor, the membrane modules/bioreactor must be designed to allow for the development of thick biofilms. In addition, options for controlling the biofilm thickness need to be investigated.     

低溶解氧下微膨胀污泥对污染物的去除性能

维持SBR反应器好氧段的平均DO为0.30 mg/L,采用好氧/缺氧的运行方式研究了微膨胀污泥在低溶解氧状态下去除污染物的效果.结果表明:在丝状菌污泥微膨胀状态下反应器的除污效果仍较好,出水SS含量很低,对COD、氨氮的去除率分别可达80%、90%以上,同时可以节省曝气量约25%.可见,在低溶解氧状态下采用微膨胀活性污泥处理生活污水是可行的.     

连续流短程同步硝化反硝化启动及影响因素研究

在温度为30℃时,通过控制生物倍增反应器中溶解氧为0.3～0.5mg,/L、pH值为7.5～8.5,实现了连续流短程同步硝化反硝化的启动,并研究了低温和溶解氧对连续流短程同步硝化反硝化的影响.结果表明:采用阶段降温的方法,经过42天的培养,连续流短程同步硝化反硝化在10℃稳定运行;相同溶解氧下,温度在15～22℃变化时...     

太阳能预热/生物接触氧化/人工湿地处理西藏高原污水

针对西藏高原地区海拔高、气温低、空气稀薄、太阳辐射强、污水处理技术和工艺尚不成熟等情况,提出一种太阳能预热/地埋式一体化生物接触氧化/复合式人工湿地污水处理工艺。介绍了其工艺流程、设计参数、经济技术指标、设计体会和初期运行效果等,可为我国高原地区小城镇生活污水处理设计提供参考。