Performance of duckweed (Lemna minor L.) on different types of wastewater treatment

Duckweed (Lemna minor L.) has a wide application in Turkey having suitable climatic conditions. In this study, the growth of duckweed was assessed in laboratory scale experiments. They were fed with municipal and industrial wastewater at constant temprature. COD, total nitrogen (TN), total phosphorus (TP) and ortho-phosphate (OP) removal efficiencies of the reactors were monitored by sampling influent and effluent of the system. Removal efficiency in this study reflects optimal results: 73-84% COD removal, 83-87% TN removal, 70-85% TP removal and 83-95% OP removal. The results show that the duckweed-based wastewater treatment is capable of treating the laboratory wastewater.     

Removing nitrogen and phosphorus from simulated wastewater using algal biofilm technique

Algal biofilmtechnology is a new and advanced wastewater treatment method. Experimental study on removing nitrogen and phosphorus from simulated wastewater using algal biofilm under the continuous light of 3500 Lux in the batch and continuous systems was carried out in this paper to assess the performance of algal biofilm in removing nutrients. The results showed that the effect of removing nitrogen and phosphorus by algal biofilm was remarkable in the batch system. The removal efficiencies of total phosphorus (TP), total nitrogen (TN), ammonia-nitrogen (NH₃-N), and chemical oxygen demand (COD) reached 98.17%, 86.58%, 91.88%, and 97.11%, respectively. In the continuous system, hydraulic retention time (HRT) of 4 days was adopted; the effects of removing TP, TN, NH₃-N, and COD by algal biofilm were very stable. During a run of 24 days, the removal efficiencies of TP, TN, NH₃-N, and COD reached 95.38%, 83.93%, 82.38%, and 92.31%, respectively. This study demonstrates the feasibility of removing nitrogen and phosphorus from simulated wastewater using algal biofilm.     

串联式垂直流生态滤池处理农村生活污水的试验研究

对串联式垂直流生态滤池处理农村生活污水进行了为期5个月的现场试验研究。结果表明：通过该工艺,污水中的COD、氨氮、总氮和总磷等污染物均得到了有效去除,在进水COD、氨氮、总氮和总磷平均质量浓度为73.19、25.08、48.55、0.55 mg·L-1时,平均去除率依次为65.6%、71.6%、58.7%、86.9%。COD、氨氮和总磷的去除主要发生在第一级生态滤池的进水0～40 cm阶段,而总氮浓度基本呈均匀下降趋势。串联式生态滤池对各污染指标较好的去除效果也证明了其是一种适合农村分散式污水处理、解决农村污水肆意排放的新途径。     

呼伦湖冰封期污染特征分析及对水处理的意义

以内蒙古呼伦湖为研究对象,对其在冰封过程中总氮、总磷和有机物在冰体和水体中的浓度及分布特征及其在呼伦湖的空间变异性进行分析。结果表明,冰封条件下,呼伦湖水体中总氮、总磷和有机物的含量均大于其在对应冰体中的含量,其含量均值分别是其对应冰体中的3.144倍、2.200倍和3.042倍,即低温冷冻过程对水体中的污染物有一定的浓缩效应;水体中各营养盐和有机物的空间变异性明显小于其在冰体中的;从固-液相平衡理论、结晶学理论和热力学理论三个方面对冷冻浓缩效应做出了合理的解释。研究认为,可以将冷冻浓缩效应运用到给水处理和污水处理领域,这样既可以进行大规模的处理,也可以节约资源、保护环境。     

Classification of contaminants and treatability evaluation of domestic wastewater

Long-term sampling and analysis were conducted in a domestic wastewater treatment plant for the investigation on the characteristics of the representative contaminants in raw sewage such as SS, COD, BOD₅, TP, and TN. All these constituents were classified into dissolved and suspended groups by using a 0.45-μm membrane filter, and the concentration of each constituent in each group was analyzed. As a result, almost 100% of the SS was found to be suspended matter, as well as about 65% of COD, 60% of BOD₅, 50% of P, and 20% of N. All these could be easily removed by sedimentation or coagulation/sedimentation. A treatability evaluation diagram was proposed for a rational selection of wastewater treatment process in accordance with raw water quality.     

丝瓜对食品废水的净化功能及经济效益

本文研究了丝瓜（Ｌｕｆｆａｃｙｌｉｎｄｒｉｃａ）在水面上的水培技术，对食品工业废水（啤酒废水）的净化功能及其经济效益。其试验结果表明：采用水培技术将丝瓜栽种在水面上是完全成功的。该法已经被应用到无锡市酿酒总厂食品工业废水净化处理。在５月份，丝瓜对啤酒废水中污染物ＴＮ的净化率为７８．６％，ＴＰ７８．０％，ＮＨ＋＿４－Ｎ９９．６％，ＣＯＤ２２．５％，浊度８０．９％。在６月份，丝瓜的净化率为ＴＮ８９．１％，ＴＰ９０．４％，ＮＨ＋＿４－Ｎ９９．２％，ＣＯＤ４４．１％和浊度８６．４％。由此可见，丝瓜是一种对食品废水净化的优良植物，其经济效益也很显著，每亩水面丝瓜（果实）可达２０００ｋｇ～２５００ｋｇ，经济价值达２０００元～２５００元。     

呼伦湖冰封期污染特征分析及对水处理的意义

以内蒙古呼伦湖为研究对象,对其在冰封过程中总氮、总磷和有机物在冰体和水体中的浓度及分布特征及其在呼伦湖的空间变异性进行分析。结果表明,冰封条件下,呼伦湖水体中总氮、总磷和有机物的含量均大于其在对应冰体中的含量,其含量均值分别是其对应冰体中的3.144倍、2.200倍和3.042倍,即低温冷冻过程对水体中的污染物有一定的浓缩效应;水体中各营养盐和有机物的空间变异性明显小于其在冰体中的;从固-液相平衡理论、结晶学理论和热力学理论三个方面对冷冻浓缩效应做出了合理的解释。研究认为,可以将冷冻浓缩效应运用到给水处理和污水处理领域,这样既可以进行大规模的处理,也可以节约资源、保护环境。     

成都市道路地表径流污染及对策

城市道路地表径流污染已经成为城市水体恶化的重要原因之一。2006年8月-11月,通过对成都市9条不同类型道路6次降雨径流水质的监测分析,探讨了成都市路面径流污染的现状、成都市道路地表径流的污染负荷及道路地表径流中污染物之间的相关性关系。结果表明,成都市道路地表径流中污染物SS、COD、TN、TP的含量高,浓度均超出地表水环境质量Ⅴ级标准。成都市道路地表径流的年污染负荷为LCOD=3.1×104t,LTN=1.19×104t,LTP=1174.9 t,LZn=109.46 t。SS浓度与污染物COD、TN、TP、Zn浓度之间存在较好的相关关系(R2>0.8)。可以通过控制径流系数、削减径流中的污染物含量和污染物总量控制3个方面的措施来进行道路地表径流污染的削减。     

城市雨水管网降雨径流污染特征及对受纳水体水质的影响

以北京市城区和近郊区选取的2个不同下垫面类型的汇水小流域为代表,在2008—2009年共进行了4场降雨过程的雨水管网出口和下游受纳水体水质同步监测.研究结果表明,分流制雨水管网降雨径流污染严重,其中悬浮物浓度高于城市污水,COD、氨氮、总磷和总氮浓度略低于城市污水,但明显高于《地表水环境质量标准》（GB3838—2002）中的Ⅴ类标准,以及《城镇污水处理厂污染物排放标准》（GB18918—2002）中的一级B标准;木樨园小流域由于绿地面积比例小,道路面积比例大,城乡结合部地带环境卫生相对较差,雨水管网降雨径流各污染物的EMC浓度比西蒲小流域高21.4%—246.5%.雨水管网降雨径流存在一定程度的初期冲刷效应;雨水管网降雨径流中COD和总磷与悬浮物之间具有较强的相关性.管网降雨径流使受纳水体污染物浓度升高16.9%—541.7%,其中悬浮物、COD和氨氮升高幅度最大.增加城市绿地可明显降低降雨径流中的悬浮颗粒物及其携带的有机污染物的含量.     

Pollutant removal by an integrated vertical-flow constructed wetland treating simulated river water by reoxygenation

The effects and mechanism of chemical oxygen demand (COD), nitrogen, and phosphorus concentration removal by an integrated vertical-flow constructed wetland were studied in the wetland system during one inlet–outlet operating period, in two typical stages (each stage is connective 24 h, sampled once every 4 h). The concentration of ammonia decreased along the flow direction in the system, while levels of nitrate (NO₃^?-N) increased. In one operating period, total nitrogen (TN) concentration fell with rising operation time due to evacuative reoxygenation. The TN and NH₃-N removal rates in the system were 26.6% and 97.5%, respectively. COD decreased rapidly in the early stages and more gradually in the direction of water flow of the wetland system. Average total phosphorus (TP) removal rate was 20.71%. TN and NO₃^?-N levels in water of the wetland had a tendency to decline gradually with increasing operation time. Ammonia concentrations displayed only a small variation with operation time. The results also indicated that the wetland was able to maintain its temperature. The oxygen content differed during the various operating stages and exerted a marked influence on COD, TP, and TN removal.     

Hydrologic and water quality performance of a laboratory scale bioretention unit

A bioretention unit (BRU) or cell is a green infrastructure practice that is widely used as a low impact development (LID) technique for urban stormwater management. Bioretention is considered a good fit for use in China’s sponge city construction projects. However, studies on bioretention design, which incorporates site-specific environmental and social-economic conditions in China are still very much needed. In this study, an experimental BRU, consisted of two cells planted with Turf grass and Buxus sinica,was tested with eighteen synthesized storm events. Three levels (high, median, low) of flows and concentrations of pollutants (TN, TP and COD) were fed to the BRU and the performance of which was examined. The results showed that the BRU not only delayed and lowered the peak flows but also removed TN, TP and COD in various ways and to different extents. Under the high, medium and low inflow rate conditions, the outflow peaks were delayed for at least 13 minutes and lowered at least 52%. The two cells stored a maximum of 231 mm and 265 mm for turf grass and Buxus sinica, respectively. For both cells the total depth available for storage was 1,220 mm, including a maximum 110 mm deep ponding area. The largest infiltrate rate was 206 mm/h for both cells with different plants. For the eighteen events, TP and COD were removed at least 60% and 42% by mean concentration, and 65% and 49% by total load, respectively. In the reservoir layer, the efficiency ratio of removal of TN, TP and COD were 52%, 8% and 38%, respectively, within 5 days after runoff events stopped. Furthermore, the engineering implication of the hydrological and water quality performances in sponge city construction projects is discussed.

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城市小集水区降雨径流污染来源解析

利用深圳市王家庄集水区的降雨径流水质监测数据,运用正定矩阵因子分解法（PMF）定量解析了单个城市小集水区降雨径流污染的主要来源。结果表明：研究区降雨径流的主要污染源为城市污水、管内沉积物和地表径流。其中城市污水以输出氨氮（NH3-N）和总氮（TN）为主,管内沉积物是化学需氧量（CODCr）、总磷（TP）和生化需氧量（BOD5）的主要来源,地表径流为固体悬浮物（SS）的主要来源。PMF模型可作为土地利用方式均一的单个城市小集水区降雨径流污染源解析的有效方法之一,主要污染源的廓线能否保持相对稳定是该模型在降雨径流污染源解析时的主要约束条件。     

人工湿地组合生态工艺对规模化猪场养殖废水的净化效果研究

研究了表面流、水平潜流和垂直潜流人工湿地以及地下渗滤系统组合生态工艺对模拟和实际猪场养殖废水的净化效果。结果表明,在进水ρ（COD）=709.2 mg.L-1,ρ（TN）=597.1 mg.L-1,ρ（NH4＋-N）=560.4 mg.L-1和ρ（TP）=42.5 mg.L-1的质量浓度条件下组合生态系统对于COD、TN、NH4＋-N和TP的去除率分别可以达到87%、95%、97%和95%,其中COD的去除主要在第一级表面流人工湿地,NH4＋-N和TN去除主要是在水平潜流和垂直潜流人工湿地,水平潜流和垂直潜流人工湿地对溶解性磷酸盐去除效果明显,地下渗滤起到进一步稳定出水水质的作用。水平潜流和垂直潜流人工湿地的运行结果对比表明,后者对污染物的去除率均高于前者。     

太湖流域农村生活污水产排污系数测算

选取太湖流域典型地区9户农户(高、中、低收入水平各3户)作为研究对象,采用现场监测及入户调查的方法对农户生活污水各类污染物产排污系数进行系统定量研究。结果表明,收入水平对农户总生活污水中TN、NH4+-N、TP产污系数无显著影响,但对污水量、COD产污系数及总生活污水中各类污染物排污系数影响显著,均表现为高收入农户中收入农户低收入农户。厕所污水对污水污染总负荷贡献率极高,COD占67%以上,TN、NH4+-N、TP占84%以上,因此,厕所污水的利用与处理率是影响污染物排污系数的主导因素,而农业收入水平及化粪池类型则对这2种因素影响显著。     

Influence of the sewage irrigation on the agricultural soil properties in Tongliao City, China

Increasing shortages of fresh water has led to greater use of treated wastewater for irrigation of crops. This study evaluates the spatial variability of soil properties after irrigation with wastewater and freshwater. Geostatistical techniques were used to identify the variability of soil properties at the different sites. A set of physical and chemical soil properties were measured including total nitrogen (TN), total phosphorus (TP), organic matter (OM) and soil moisture. The TN concentration levels varied from 567 to 700 mg·kg^-1, while OC levels ranged from 7.3 to 16.3 mg·kg^-1 in wastewater-irrigated zones. The concentration levels of TP were between 371.53 and 402.88 mg·kg^-1 for the wastewater-irrigated sites. Wastewater irrigation resulted in higher TN, TP and OM concentrations by 18.4%, 8% and 25%, respectively. The highest TN and OM occurred along the wastewater trunk. It was also observed that nitrogen concentrations correlate with the soil's organic matter. The increase of salinity may be associated with the increase of pH, which might suggest that a reduction of pH will be beneficial for plant growth due to the decrease of salinity. The average concentrations of nitrogen in topsoil were higher than those in subsurface soils in irrigated areas. Such differences of the N profile might be due to variations in organic matter content and microbial populations. Consistent with TN and OM, soil C:N decreased significantly with an increase of depth. This phenomenon possibly reflects a greater degree of breakdown and the older age of humus stored in the deeper soil layers. The analysis of pH levels at different depths for the three sites showed that pH values for wastewater irrigation were slightly lower than the controlled sites at the same depths.     

人工湿地处理富营养化水体的效果研究

通过在北京市野生动物救护中心构建表流湿地与潜流湿地相结合的复合人工湿地处理富营养化水体,研究该复合人工湿地对总氮（TN）、总磷（TP）及水体浊度的去除效果。结果表明：人工湿地对TP的去除效果好于对TN的去除效果,经过人工湿地处理的富营养化水体,表流湿地、潜流湿地和复合人工湿地对TP的平均去除率可分别达42%、55%、60%,对TN的平均去除率分别为27%、30%、34%,对水体浊度的平均去除率分别达43%、55%、75%。复合人工湿地对TP、TN以及浊度的去除效果受水体温度和溶解氧（DO）的影响,通过相关性分析发现,TP、TN和浊度的去除量与水体中的DO水平之间存在显著的负相关性,而与水体温度有正相关性,在显著性水平为0.05的条件下,相关系数分别为-0.829、-0.767、-0.765和0.674、0.757、0.774。复合人工湿地对TP、TN及浊度的去除率高于表流湿地和潜流湿地,表明复合人工湿地具有优于表流湿地和潜流湿地的整体性功能,能有效提高人工湿地对TN、TP以及浊度的去除率。     

涟江上游表层岩溶泉水污染源解析

为明确涟江上游表层岩溶泉水化学污染特征及其污染来源,选取区域内7个地表饮用泉作为研究对象.测定泉水水温(T)、电导率(EC)、溶解氧(DO)、pH、总氮(TN)、总磷(TP)、氨氮(NH4-N)、硝氮(NO₃-N)、高锰酸盐指数(COD)并研究其与泉眼半径200、500、1000 m范围内耕地、住宅用地及交通用地面积的相关性.研究结果表明,依据地表水环境质量标准(GB3838-02)等水质标准,涟江上游7个表层岩溶泉水TN均超标,耕地周围的泉水TP、NH₄-N、NO₃-N也超过标准值,表明该区域表层岩溶泉水总体高N而局部高P的污染特征.主成分分析表明农业活动对泉水TN、TP、NH₄-N、NO₃-N及COD含量产生了一定的影响.泉眼半径200 m范围内耕地面积与TP、NH₄-N显著正相关,表明小范围内农业活动是泉水N、P污染的主要源头;500 m范围内EC与住宅用地面积显著正相关,表明较大规模人类聚居可能造成泉水离子成分偏复杂.从保护地表饮用泉的角度出发,建议泉眼半径200 m内减少农业活动强度及频率,泉眼半径500 m内控制人口密度及日常生活排污量.     

风车草对生活污水的净化效果及其在人工湿地的应用

研究了风车划（Cyerus alternifolius）的生长特性和对生活污水的净化效果。风车草全年保持生长，即使在冬天仍能维持一定的生长速率。风车草在生活污水中培养10d后，污水中TN、TP、COD和BOD的去除率分别达到91％、92％、70％和73％，其中风车草对N、P的吸收量分别占净化量的55％和53％。种植风车草的潜流型人工湿地对TN、TP、COD和BOD的去除率分别为64％、47％、74％和74％，与不种植物的人工湿地相比，TN、TP、COD和BOD的去除率分别提高了28％、19％、14％和13％。图2表3参12     

Comparative experiment on treating digested piggery wastewater with a biofilm MBR and conventional MBR: simultaneous removal of nitrogen and antibiotics

A biofilm membrane bioreactor (BF-MBR) and a conventional membrane bioreactor (MBR) were parallelly operated for treating digested piggery wastewater. The removal performance of COD, TN, NH₄ ⁺-N, TP as well as antibiotics were simultaneously studied when the hydraulic retention time (HRT) was gradually shortened from 9 d to 1 d and when the ratio of influent COD to TN was changed. The results showed that the effluent quality in both reactors was poor and unstable at an influent COD/TN ratio of 1.0±0.2. The effluent quality was significantly improved as the influent COD/TN ratio was increased to 2.3±0.5. The averaged removal rates of COD, NH₄ ⁺-N, TN and TP were 92.1%, 97.1%, 35.6% and 54.2%, respectively, in the BF-MBR, significantly higher than the corresponding values of 91.7%, 90.9%, 17.4% and 31.9% in the MBR. Analysis of 11 typical veterinary antibiotics (from the tetracycline, sulfonamide, quinolone, and macrolide families) revealed that the BF-MBR removed more antibiotics than the MBR. Although the antibiotics removal decreased with a shortened HRT, high antibiotics removals of 86.8%, 80.2% and 45.3% were observed in the BF-MBR at HRTof 5–4 d, 3–2 d and 1 d, respectively, while the corresponding values were only 83.8%, 57.0% and 25.5% in the MBR. Moreover, the BF-MBR showed a 15% higher retention rate of antibiotics and consumed 40% less alkalinity than the MBR. Results above suggest that the BF-MBR was more suitable for digested piggery wastewater treatment.

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不同水力负荷下凤眼莲去除氮、磷效果比较

采用人工模拟方法,研究了不同水力负荷(0.14、0.20、0.33和1.00m3.m-2.d-1)对凤眼莲去除富营养化水体氮、磷效果的影响,试验期间进水TN、NH4+-N、NO3-N、TP平均质量浓度分别为4.85、1.33、2.92和0.50mg.L-1。结果表明,凤眼莲净化系统对富营养化水体具有较好的去除效果,低水力负荷(0.14、0.20m3.m-2.d-1)下,出水TN、NH4+-N和TP均达到了GB3838—2002《地表水环境质量标准》的Ⅳ类水质标准;当水力负荷提高到1.00m3.m-2.d-1后,出水TN、NH4+-N、NO3-N和TP质量浓度明显上升。4种水力负荷下,凤眼莲净化系统对TN和TP去除率分别为84.95%和80.65%、73.87%和73.04%、51.60%和64.05%、30.77%和47.79%,即随水力负荷的提高而降低;相应的TN、TP去除负荷分别为0.58和0.06、0.72和0.07、0.83和0.11、1.47和0.23g.m-2.d-1,即随水力负荷的提高而增加。综合考虑净化效果和污水处理能力,本试验条件下凤眼莲系统的水力负荷宜控制在0.33m3.m-2.d-1。