浅水体浮萍污水净化系统的除氮途径

以稀释的猪场厌氧污水为供试水样,少根紫萍为供试生物材料,对夏、冬2季浅水体浮萍污水净化系统TN、NH4 -N和NOx--N(NO2--N与NO3--N之和)的去除途径进行了试验研究。结果表明,在夏季气温条件下,TN通过气态氨挥发、浮萍系统吸收/吸附NH4 -N和NOx--N得以去除,3途径去除的N分别占TN去除量的30.5%、15.9%和53.6%;NH4 -N通过气态氨挥发、浮萍系统吸收/吸附和硝化反应得以去除,3途径去除的N分别占NH4 -N总去除量的33.1%、17.3%和49.6%;NOx--N则完全通过浮萍系统吸收/吸附得以去除。在冬季气温条件下,TN通过气态氨挥发和浮萍系统吸收/吸附NH4 -N得以去除,2途径去除的N分别占TN去除量的31.7%和68.3%;NH4 -N通过气态氨挥发、浮萍系统吸收/吸附和硝化反应得以去除,3途径去除的N分别占NH4 -N总去除量的28.9%、69.5%和1.6%;而水体中的NOx--N含量始终保持稳定。     

拉萨市城市生活污水的水质监测分析

拉萨市城市生活污水由居民日常生活废水和企业生产废水组成 ,尚未建城市污水处理厂 ,且城市污水管网不完善 ,对拉萨河造成一定程度的污染 .本文主要对拉萨市城市生活污水中的CODCr,BOD5,NH3 N ,TP ,SS等主要指标进行了监测分析 ,进而为拉萨市城市污水处理厂的建设提供一些基础数据 .1　水样的采集和测定拉萨市的居民生活废水与企业生产废水混合后 ,由一根管道汇总到拉萨市西郊东嘎河桥下面的总排污口 ,与清洁水混合 ,然后排入拉萨河 ,水样采集点即位于该总排污口 .采样分两个阶段 :第一阶段为 2 0 0 3年 3月 2 5日 1 1∶0 0至 3月 2 7…     

垂直潜流人工湿地净化北方微污染水体试验研究

为研究垂直潜流人工湿地对北方微污染水体中COD、氮和磷的去除效果及去除机理,在室内选用混合土(由炉渣与种植土按比例混合而成)、石英砂和陶粒作为填料,以天津当地常见植物黄花鸢尾为植被构建了垂直潜流人工湿地处理微污染景观湖水和雨季的初期雨水;除冬季冰封期暂停运行外,通过对系统不同季节运行数据的分析,考察了不同季节环境条件下垂直潜流人工湿地对我国北方城市微污染水体的净化效果及影响因素。结果表明:不同季节条件下,该系统对污染物均有着良好的去除效果和抗冲击负荷能力。微污染景观水和雨季初期雨水经垂直潜流人工湿地系统处理后,出水COD、NH4+-N及TP的质量浓度可分别优于GB 3838—2002《地表水环境质量标准》的IV类、III类和II类水质标准(研究阶段进水TP≤0.80 mg·L-1),COD、NH4+-N和TP的阶段平均去除率最高可分别达80%、91%和82%;TN的去除效果受季节变化波动较大,阶段平均去除率在32%~78%,温度较低季节或原水水质较差时有待处理水回流或辅加其他技术手段以提高脱氮效果。垂直潜流人工湿地对北方微污染水体有着较好的净化效果,能够有效地预防地表水体富营养化的发生,有利于城市水环境质量的改善和水资源的循环利用,具有良好的发展应用前景。     

多级蚯蚓生态滤池处理生活污水研究

采用多级蚯蚓生态滤池对生活污水进行处理研究,考察多级蚯蚓生态滤池对污水中各类污染物的去除效果.试验结果表明,多级蚯蚓生态滤池连续运行80d,滤池对CODCr、NH4+-N和TP的去除效果良好,去除率分别为80.4%—98.6%、95.5%—99.5%和93.7%—99.7%,出水水质符合要求.但是滤池对TN去除效果不稳定,不加碳源TN去除率降低,最低为26.0%左右,添加碳源后TN去除率维持在60%左右.其中进水中C/N比为3.07,出水中一级滤池、二级滤池和三级滤池的C/N比分别为1.56、0.88和0.72,沿程水样C/N比呈逐级下降的趋势.运行22d后,在二级滤池出水中添加葡萄糖调节C/N比为3—6,总氮去除率上升.对TN去除研究分析,推断出碳源不足是TN去除率降低的重要原因.相比单级的蚯蚓生态滤池,多级蚯蚓生态滤池生活污水处理的更加彻底,应用前景更加广泛。     

固定化藻膜去除水中氮磷的模拟研究

针对富营养化水体生物修复和污水深度处理氮磷的去除,将细颤藻、水绵、水网藻、栅裂藻固定在纤维填料上,形成固定化藻膜。用固定化藻膜处理模拟富营养化湖水、实际富营养化湖水、城市污水二级出水、低质量浓度生活污水,考察固定化藻膜去除氮磷的效果。实验结果表明,固定化藻膜具有良好的去除磷、氨氮能力,对水中有机物去除也有一定的促进作用。对TP质量浓度小于5.0mg·L-1,NH4 -N质量浓度小于34.0mg·L-1的污染水体,四种藻膜都有良好的去除氮磷能力,其中栅裂藻去除TP、NH4 -N的能力最强。综合除污能力和藻细胞的可固定性,水绵应是最佳的备选藻种。研究结果显示,固定化藻膜具有良好的除污性能,预示了悬浮载体将在水体生物修复、氧化塘污水处理方面具有重要的潜在应用价值。     

微生物絮凝剂产生菌的筛选及其絮凝除浊性能

采用某污水处理厂活性污泥富集的菌种 ,通过筛选获得了 1 0株絮凝除浊性能较强的菌株。以其中絮凝性能最优的菌株GS7为研究对象 ,探讨了影响其絮凝作用的主要因素。结果表明 ,GS7的最适生长条件为 :培养基pH值 6、培养时间 1 8h、培养温度 30℃。当废水pH值为 8左右时 ,GS7的絮凝效果最好。在废水中投加少量的二价金属离子Ca2 +可大大提高GS7的絮凝除浊率。GS7处理城市河涌污水等实际废水时浊度去除率可达 93.5%。     

微波法磷改性斜发沸石的结构及水中除砷的研究

采用固固相、固液相同晶取代对斜发沸石进行微波法磷改性，并对改性前后的矿样采用化学分析，XRD，^31P MAS NMR等手段表征。结果表明，虽然微波磷改性不能改变沸石单斜晶系的主体骨架结构，但由于脱Al，脱Si和P同晶取代，使晶胞体积收缩，结晶度下降，比表面积、孔体积明显减小，骨架中Si和Al的键合方式发生变化，有四配位硅的Si—O—P结构出现，该结构是沸石阴离子交换的结构基础。沸石去除水中砷的结果表明，改性前，沸石去除水中砷的能力很小，属表面物理吸附，改性后，沸石去除水中砷的能力明显增强，属阴离子交换。而且水介质的酸度和同晶取代方法对沸石除砷都有明显影响。     

微生物絮凝剂产生菌的筛选及其絮凝凝除浊性能

采用某污水处理厂活性污泥富集的菌种，通过筛选获得了１０株絮除浊性能较强的菌株。以其中絮凝性能最优的菌株ＧＳ７为研究对象，探讨了影响其絮凝作用的主要因素。结果表明，ＧＳ７的最适生长条件为：培养基ＰＨ６、培养时间１８ｈ、培养温度３０℃。     

山东省地下水硝酸盐溯源研究

针对山东全省农村地区进行地下水取样,采用离子交换色层法对地下水NO3--N质量浓度大于10 mg·L-1的地下水样品进行预处理,做溯源研究,同时采集当地植物、化学肥料、人畜粪便、土壤等样品,测定δ15N值,以针对山东地区,对现存的δ15N值数据库进行完善与补充,使本研究更具代表性与准确性。研究结果表明,如以研究区域整体为单位,有35.45%地下水样品的NO3--N来自于粪肥污染,有27.1%的地下水样品是受化肥污染,还有37.45%的地下水样品的NO3--N污染来自于化肥、粪肥以及生活污水的混合污染。作者还进一步分析了地下水中NO3--N平均质量浓度高于20 mg·L-1的烟台和潍坊,结果表明,烟台地区的地下水NO3--N污染有55.56%来自于粪肥污染,有5.56%来自于化肥污染,有38.88%来自于化肥、粪肥以及生活污水的混合污染;潍坊地区的地下水NO3--N污染有16.13%来自于粪肥污染,有48.39%来自于化肥污染,还有35.48%来自于化肥、粪肥以及生活污水的混合污染。     

一株好氧反硝化茵的分离鉴定及其混合应用特性研究

采用溴百里酚（BTB）鉴定培养基和稀释平板法从南京市某市政污水处理厂曝气池污水样本中分离筛选得到1株好氧反硝化细菌,经16SrDNA序列同源性比较和系统发育分析初步鉴定为反硝化产碱杆菌（Alcaligenes denitrificns）,并将其命名为菌株BMB—N6。研究了菌株BMB—N6在不同浓度亚硝态氮条件下的反硝化能力,运用正交试验设计探讨了该菌株最适的好氧反硝化条件,并且在实验室和大田条件下分别考察了菌株BMB—N6与蛋白质降解菌BMB-LA和氨氮脱除菌BMB—HKF复配形成的混合菌制剂的反硝化能力。结果表明,菌株BMB—N6在8h内对亚硝态氮的去除率可达94％,其最适亚硝态氮去除条件为摇床转速50r·min^-1,C／N比值4,pH6,温度35℃。在实验室条件下以菌株BMB-N6为基础制成的混合菌制剂在12h内可去除90％的亚硝态氮,在大田应用中7d内可去除80％的亚硝态氮。     

人工快速渗滤法处理小城镇污水的模拟试验研究

小城镇污水既是水资源的主要污染源,同时也是可利用水资源的重要组成部分,高效率、低成本的小城镇污水处理技术是农业生态安全和工程节水的急需。研究采用人工快速渗滤方法处理小城镇污水,在湿干比一定（湿干比1∶3）的条件下设3种填料比[V（土）∶V（砂）=1∶1、2∶1和3∶1）和3种不同水力负荷周期[短周期（0.5 d进水,1.5 d落干）、中周期（1 d进水,3 d落干）和长周期（3 d进水,9 d落干）]进行交叉试验。跟踪测定处理后水中COD、总磷、凯氏氮和铵氮的去除率。结果表明,系统的COD和总磷去除效果较好,最高去除率分别达到73.19%和54.86%。COD的去除受水力负荷周期影响较大,在长水力负荷周期条件下去除效率高,总磷的去除受水力负荷周期的影响小。系统对凯氏氮和铵氮的去除效率偏低,两者的最高去除率分别为46.67%和40.67%,均在长周期条件下取得。     

大清河人工快速渗滤系统示范工程效果分析

以滇池流域受污染的大清河为研究对象,开展了人工快速渗滤系统（CRI）示范工程研究,根据气候条件、进水水质和运行工艺分为6个工况,以探索污染负荷和工艺参数对CRI运行性能的影响。实验结果表明：水力负荷2 m.d-1、湿干比1：1是该示范工程运行的最优工艺条件。CRI系统对有机物（COD）的平均去除率范围17.42%～63.75%;对氨氮去除效果受进水水质影响,高、低污染负荷下NH3-N去除率分别为56.71%、85.48%;CRI示范工程硝化作用较强,反硝化能力较弱,对TN的平均去除率范围为10.69%～28.29%;CRI示范工程对TP的平均去除率为27.62%,最佳工艺条件下为50.23%。CRI系统可通过对填料进行优化组合、适当增大饱水带高度,强化除磷脱氮能力。     

Evaluation of the k-nearest neighbor method for forecasting the influent characteristics of wastewater treatment plant

The k-nearest neighbor (k-NN) method was evaluated to predict the influent flow rate and four water qualities, namely chemical oxygen demand (COD), suspended solid (SS), total nitrogen (T-N) and total phosphorus (T-P) at a wastewater treatment plant (WWTP). The search range and approach for determining the number of nearest neighbors (NNs) under dry and wet weather conditions were initially optimized based on the root mean square error (RMSE). The optimum search range for considering data size was one year. The square root-based (SR) approach was superior to the distance factor-based (DF) approach in determining the appropriate number of NNs. However, the results for both approaches varied slightly depending on the water quality and the weather conditions. The influent flow rate was accurately predicted within one standard deviation of measured values. Influent water qualities were well predicted with the mean absolute percentage error (MAPE) under both wet and dry weather conditions. For the seven-day prediction, the difference in predictive accuracy was less than 5% in dry weather conditions and slightly worse in wet weather conditions. Overall, the k-NN method was verified to be useful for predicting WWTP influent characteristics.     

Seasonal variations of organic-carbon and nutrient transport through a tropical estuary (Tsengwen) in southwestern Taiwan

This paper reports the fluvial fluxes and estuarine transport of organic carbon and nutrients from a tropical river (Tsengwen River), southwestern Taiwan. Riverine fluxes of organic carbon and nutrients were highly variable temporally, due primarily to temporal variations in river discharge and suspended load. The sediment yield of the drainage basin during the study period (1995–1996, 616 tonne km^–2 year^–1) was ca. 15 times lower than that of the long-term (1960–1998) average (9379 tonne km² year^–1), resulting mainly from the damming effect and historically low record of river water discharge (5.02 m³ s^–1) in 1995. The flushing time of river water in the estuary varied from 5 months in the dry season to >4.5 days in the wet season and about 1 day in the flood period. Consequently, distributions of nutrients, dissolved organic carbon (DOC) and particulate organic carbon (POC) were of highly seasonal variability in the estuary. Nutrients and POC behaved nonconservatively but DOC behaved conservatively in the estuary. DOC fluxes were generally greater than POC fluxes with the exception that POC fluxes considerably exceeded DOC fluxes during the flood period. Degradation of DOC and POC within the span of flushing time was insignificant and may contribute little amount of CO₂ to the estuary during the wet season and flood period. Net estuarine fluxes of nutrients were determined by riverine fluxes and estuarine removals (or additions) of nutrients. The magnitude of estuarine removal or addition for a nutrient was also seasonally variable, and these processes must be considered for net flux estimates from the river to the sea. As a result, nonconservative fluxes of dissolved inorganic phosphorus (DIP) from the estuary are –0.002, –0.09 and –0.59 mmol m^–2 day^–1, respectively, for dry season, wet season and flood period, indicating internal sinks of DIP during all seasons. Due to high turbidity and short flushing time of estuarine water, DIP in the flood period may be derived largely from geochemical processes rather than biological removal, and this DIP should not be included in an annual estimate of carbon budget. The internal sink of phosphorus corresponds to a net organic carbon production (photosynthesis–respiration, p–r) during dry (0.21 mmol m^–2 day^–1) and wet (9.5 mmol m^–2 day^–1) seasons. The magnitude of net production (p–r) is 1.5 mol m^–2 year^–1, indicating that the estuary is autotrophic in 1995. However, there is a net nitrogen loss (nitrogen fixation–denitrification < 0) in 1995, but the magnitude is small (–0.17 mol m^–2 year^–1).     

Coexistence of species of Acartiidae (Copepoda) in the Cochin Backwater,a monsoonal estuarine lagoon

A study was made of copepods of the family Acartiidae which form the dominant component of the plankton in the Cochin Backwater (Kerala, India). At least nine species inhabit the backwater at one time or another, more than have been recorded for any other area. Reasons were sought for this diversity. The surface plankton was sampled from the head of the estuary to the mouth and from one season to another. There were large seasonal changes in salinity (0 to 35 ), due to monsoonal flooding, and associated changes in species composition. Species diversity was highest during the dry season and lowest in the wet. It is suggested that this annual catastrophic flooding leads, in the long run, to high species diversity by imposing a regular check on interspecific competition.     

湖滨带复合型人工湿地氮磷的去除效果

湖滨带是连接湖泊水域生态系统与陆地生态系统的一个功能过渡区,是湖泊的最后一道保护屏障。在河流的入湖口建造湖滨湿地,可有效净化入湖径流中携带的部分有机污染物、营养盐等。以云南抚仙湖北岸的湖滨湿地—马料河复合人工湿地为研究对象,探讨了湿地不同功能区去除氮磷的效果。研究表明,沉淀池除氮效果最不明显,在该区内有机氮可能发生矿化作用而转变为氨氮。有植物系统的潜流和表流区除氮效果较为明显,潜流区对氨氮、硝氮和总氮的平均去除率分别达18.0%、19.7%和22.6%;表流区对三者的平均去除率分别达50.4%、35.9%和43.5%。沉淀池对磷有一定的截留作用,且在进水污染物质量浓度较高时表现明显,平均截留率为14.9%。潜流和表流区除磷效果不明显,可能是因为湿地运行了两年多,土壤吸附交换达到平衡,影响了表流区的除磷效果。潜流区除磷效果受降雨影响较大,雨季时,总磷的平均截留率为12.1%,主要是不溶性磷的吸附和沉积;雨季末期,湿地流量较小,水体流动性差,系统内处于厌氧状态,出现磷释放现象。     

Highly efficient and selective removal of phosphate from wastewater of sea cucumber aquaculture for microalgae culture using a new adsorption-membrane separation-coordinated strategy

● A new adsorption-membrane separation strategy is used for phosphate removal. ● PVC/Zr-BT shows a selective adsorption ability to low-concentration phosphate. ● Low concentration of P below 0.05 mg/L was achieved in actual wastewater treatment. ● Algal biomass production served as a demonstration of phosphorus recycling. Enhanced phosphorus treatment and recovery has been continuously pursued due to the stringent wastewater discharge regulations and a phosphate supply shortage. Here, a new adsorption-membrane separation strategy was developed for rational reutilization of phosphate from sea cucumber aquaculture wastewater using a Zr-modified-bentonite filled polyvinyl chloride membrane. The as-obtained polyvinyl chloride/Zr-modified-bentonite membrane was highly permeability (940 L/(m²·h)), 1–2 times higher than those reported in other studies, and its adsorption capacity was high (20.6 mg/g) when the phosphate concentration in water was low (5 mg/L). It remained stable under various conditions, such as different pH, initial phosphate concentrations, and the presence of different ions after 24 h of adsorption in a cross-flow filtration system. The total phosphorus and phosphate removal rate reached 91.5% and 95.9%, respectively, after the membrane was used to treat sea cucumber aquaculture wastewater for 24 h and no other water quality parameters had been changed. After the purification process, the utilization of the membrane as a new source of phosphorus in the phosphorus-free f/2 medium experiments indicated the high cultivability of economic microalgae Phaeodactylum tricornutum FACHB-863 and 1.2 times more chlorophyll a was present than in f/2 medium. The biomass and lipid content of the microalgae in the two different media were similar. The innovative polyvinyl chloride/Zr-modified-bentonite membrane used for phosphorus removal and recovery is an important instrument to establish the groundwork for both the treatment of low concentration phosphate from wastewater as well as the reuse of enriched phosphorus in required fields.     

Effects of previous drying of sediment on root functional traits and rhizoperformance of emerged macrophytes

• Sediment desiccation alters morphological characteristics of aquatic sediment. • Alternation in morphological properties of sediment limiting root characteristics. • Fibrous-rooted macrophytes root properties extra favor nutrients removal. • Thick-rooted macrophytes exhibit higher life-span in two sediment types. Purpose of the current study was to investigate the effects of constantly wet and dried-rewetted sediments on root functional traits of emerged macrophytes and their nutrients removal abilities. It is based on the hypothesis that root characteristics and nutrients removal abilities of plants will be altered in the course of sediment desiccation. Four emerged macrophytes including two fibrous-root plants (Canna indica and Acorus calamus) and two thick-root plants (Alocasia cucullata and Aglaonema commutatum) were investigated for their root functional traits and rhizoperformance in both wet and dried-rewetted sediments. Results showed that sediment desiccation followed by rewetting substantially altered the root functional traits (root surface area, radial oxygen loss, and root activity) of plants due to adverse changes in morphological characteristics (porosity, bulk density, particle density) of dried-rewetted sediments than by wet sediments. Consequently, limited plants growth and removal of nitrogen (N), phosphorus (P) and dissolved organic carbon (DOC) were recorded in dried-rewetted sediments and their pore water than in wet sediments. Radial oxygen loss from plant roots correlated positively with root functional traits, plants growth, and removal of N, P and DOC from pore water and sediment in both sediment types. Among the macrophyte species, the fibrous-root plants having advantages root functional traits, greatly influenced the rhizospheric conditions (pH, dissolved oxygen and redox potential), and demonstrated higher N, P and DOC reduction from both sediment types. While, the thick-rooted plants with thick diameter roots (D > 1 mm) and higher rhizome exhibited longer life-span in both sediment types.     

淹水对酸性红壤磷吸附解吸特性的影响——以江西省旱地红壤和水稻土为例

采用室内培养法研究了淹水对2种酸性红壤（旱地红壤、水稻土）磷吸附解吸特性及草酸可提取态P的影响。淹水培养实验中,2种土壤分别淹水0（对照）,1、2、3、4、8周,淹水培养结束后进行P吸附解吸实验,解吸实验结束后测定土样中草酸可提取态P。结果表明：与氧化状态相比,淹水后旱地红壤P吸附量减少,水稻土淹水1、2、3周P吸附量高于氧化状态,继续淹水4和8周后P吸附量减少。淹水前后旱地红壤P吸附量均大于水稻土。用简单Langmuir方程拟合P等温吸附曲线,除淹水4周外,P最大缓冲容量（MBC）随淹水时间延长而降低。结合能常数（K）淹水前后的变化规律性差。2种土壤P解吸量随加入P量增加而增加。氧化、还原状态下,2种土壤酸性草酸铵可提取P均远远大于CaCl2解吸P,虽然水稻土吸附P量低于旱地红壤,但P解吸量无论是CaCl2解吸P还是酸性草酸铵可提取P均大于旱地红壤,主要原因在于水稻土全P及速效P含量大于旱地红壤。淹水后草酸可提取态P增加,吸附P的释放和被新近形成的铁氧化物再吸附是淹水后草酸可提取态P增加的主要原因。     

冬作季节土壤水分状况对稻田CH_4排放的影响

温室盆栽试验表明,冬作季节土壤持续淹水处理（淹水）稻田平均ＣＨ４ 排放通量显著高于干燥处理（干燥）,前者是后者的５．５８ 倍（１９９６ 年）和４．１６ 倍（１９９７ 年）。冬作季节土壤水分状况明显影响土壤Ｅｈ 和ＣＨ４ 排放的季节变化。淹水处理土壤Ｅｈ 在整个水稻生长期皆处于适宜ＣＨ４ 产生的水平,所以整个水稻生长期皆有ＣＨ４ 排放（经历烤田后例外）,而干燥处理水稻移栽４２ ｄ 后土壤Ｅｈ 才降为负值,在此期间几乎没有ＣＨ４ 排放。