Influence of photoperiod on the uptake of nitrogen and phosphorus in the water by Eichhornia crassipes and Salvinia auriculata

The main goal of this research was to quantify the concentrations of total and ammonium N, nitrate, total and soluble P in the water in the presence of Eichhornia crassipes and Salvinia auriculata, which were submitted to two different photoperiods in a 24 hours incubation period in the laboratory. The macrophytes were incubated in plastic vials of approximately 1.5 litters, with a previously prepared solution with NH4NO3, NH4Cl, and KH2PO4. Eichhornia crassipes showed the highest average rate of reduction of all the nutrients analysed in relation to Salvinia auriculata. The largest photoperiod reflected in a higher average rate of reduction of nutrients, in both plants. Therefore, we may expect that in some periods of the year (e.g. summer), the aquatic macrophytes would show higher growth rates and higher rates of nitrogen and phosphorus absorption. These results are important for the implementation and management of wastewater treatment systems in tropical areas using aquatic macrophytes.     

Correlating on-line monitoring parameters, pH, DO and ORP with nutrient removal in an intermittent cyclic process bioreactor system

The paper presents the study correlating the profile of on-line monitoring parameters and nutrient removal in an intermittent cyclic process bioreactor (ICPBR) system, thereby utilizing the parameters as operational tool. A laboratory scale ICPBR was employed to treat low C/N ratio domestic wastewater from a township. The study was conducted for correlating biological nutrient removal and on-line monitored parameters pH, dissolved oxygen (DO) and oxidation-reduction potential (ORP). The results revealed that pH, DO and ORP related with the dynamic behavior of nutrient concentration (NH4-N, NO3-N, and PO4-P) during treatment in an ICPBR system. The variation in pH and ORP of the reactor liquor correlate to conversion of ammonia (NH4-N) and nitrate (NO3-N) concentrations, respectively. As the bioconversion of ammonia nitrogen and phosphorus are related to the varying profile of the on-line monitored parameters, the profiles could possibly be used as onsite process control parameters.     

Assessing water hyacinth (Eichhornia crassopes) and lettuce (Pistia stratiotes) effectiveness in aquaculture wastewater treatment

Water hyacinth (Eichhornia crassipes) and water lettuce (Pistia stratiotes) were analyzed to determine their effectiveness in aquaculture wastewater treatment in Malaysia. Wastewater from fish farm in Semanggol Perak, Malaysia was sampled and the parameters determined included, the pH, turbidity, dissolved oxygen (DO), chemical oxygen demand (COD), biochemical oxygen demand (BOD), nitrite phosphate (PO4(3-)), nitrate (NO(3-)), nitrite (NO(-2)), ammonia (NH3), and total kjedahl nitrogen (TKN). Also, hydroponics system was set up and was added with fresh plants weights of 150 +/- 20 grams Eichhornia crassipes and 50 +/- 10 grams Pistia stratiotes during the 30 days experiment. The phytoremediation treatment with Eichhornia crassipes had pH ranging from 5.52 to 5.59 and from 4.45 to 5.5 while Pistia stratiotes had its pH value from 5.76 to 6.49 and from 6.24 to 7.07. Considerable percentage reduction was observed in all the parameters treated with the phytoremediators. Percentage reduction of turbidity for Eichhornia crassipes were 85.26% and 87.05% while Pistia stratiotes were 92.70% and 93.69% respectively. Similar reductions were observed in COD, TKN, NO(3-), NH3, and PO4(3-). The capability of these plants in removing nutrients was established from the study. Removal of aquatic macrophytes from water bodies is recommended for efficient water purification.     

PS1沼泽红假单胞菌对集约化对虾养殖废水的净化作用

应用光合细菌PS1——沼泽红假单胞菌（Rhodopseudomonas palustris）净化集约化对虾养殖废水,探讨不同温度、不同菌浓度下PS1对养殖废水的净化效果。研究结果表明：PS1可有效降低对虾养殖废水中的COD、NH4^＋-N、NO3^-N、PO4^3--P,但对NO2^--N无降解效果,反而使之持续升高;PS1对养殖废水96h的降解率受温度和添加菌浓度的影响显著（P〈0．05）。当温度为26℃时,PS1对废水的降解活性较好;不同菌浓度组间的净化效果差异明显（P〈0．05）,综合净化效果,以12．5×10^5 CFU／ml的菌浓度为宜。     

真江蓠(Gracilaria verrucosa)对网箱养殖海区的生态修复及生态养殖匹配模式

2006年8～9月,在浙江象山港花鲈(Lateolabrax japonicus)养殖网箱中吊养真江蓠(Gracilaria verrucosa)对网箱养殖造成的水体富营养化进行生态修复研究.通过45d内的平面监测、定点跟踪监测和断面监测,结果表明:该网箱养殖区水体呈严重富营养化状态,营养状态指数(E)为32.00,其营养盐分布由高浓度的中心区向周围150m非养殖水域扩散;真江蓠对养殖区的富营养化海水具有较好的修复效果:江蓠生态修复区及其相邻网箱中水体PO4-P、NO2-N、NH4-N和NO3-N含量显著低于非修复区(P＜0.01),修复区海水PO4-P、NO2-N、NH4-N和NO3-N浓度比非修复区分别降低22%～58%、24%～48%、22%～61%和24%～47%.养殖真江蓠45d后,修复区水体DO浓度和透明度显著高于非修复区(P＜0.05),DO平均提高28%,透明度平均提高30%;而修复区水体Chl-a浓度显著低于非修复区(P＜0.05),平均降低49%.通过建立基于N平衡的鱼藻生态养殖模式,每收获1kg花鲈至少需要匹配江蓠4.7 kg wet wt才可实现对鱼类排放N的完全吸收.因此网箱内栽培江蓠的混合生态养殖模式,可平衡因经济动物养殖所带来的额外营养负荷,有利于实现动物养殖环境的自我修复.     

长江口邻近海域营养盐分布特征及其控制过程的初步研究

利用1997年秋季和1998年春季对长江口邻近海域两个航次的调查结果,对该海域营养盐分布、结构特征以及其主要控制过程进行了探讨．结果表明,该海域的营养盐分布及结构具有明显的季节变化,秋季海水中NO3--N、SiO3^2-．SiSiO3^2-,Si及PO4^3--P,DOP、PP均高于春季,平均含量分别为4．97、11．6、0．44、0．26、0．82μmol·L-1,而春季则是NO2--N、NH4+-N、DON、PN含量高,平均含量分别为0．70、2．26、9．88、7．88μmol·L-·PP(54％)和PO4^3--P(51％)分别为秋季和春季磷的主要形态,两个季节氮结构基本一致,均以DON和PN为主．除春季PO4^3--P外,营养盐受长江冲淡水等陆源输入的影响而呈现近岸含量较高,溶解无机氮秋季以NO3^- -N为主而春季则以NH4^+-N为主,秋季PO4^3- -P同时来源于长江冲淡水和台湾暖流．而春季则主要来源于台湾暖流．显示出春季台湾暖流对调查海区的影响程度大于秋季．     

三峡大坝截流前后长江中上游江段水化学特性的初步调查

1997-1998年,在三峡大坝截流前后,对长江中上游地区十多个江段及若干个支流进行了多次的水质监测分析。结果表明:长江中上游水资源丰富,但污染较严重。从多项数据指标分析结果和多项资料表明,目前污染源主要为沿江工业和城市生活污水。长江干流污染远高于支流(嘉陵江除外).而大江截流对长江中上游的水质近期影响较小,可以忽略不计。       

广东大中型供水水库的氮污染与富营养化分析

20 0 0年丰水期和枯水期对广东大中型水库的氮污染和富营养化现状进行了调查。结果表明 ,在调查的 2 0个大中型供水水库中 ,水质现状总体较好 ,70 %的水库处于中营养状态以下 ,30 %的水库开始出现富营养化现象。水库的总氮浓度普遍偏高 ,氮污染成为水库富营养化的重要原因。水库的总氮和DIN浓度存在地区性差异和季节性差异。枯水期水库的总氮及DIN浓度与叶绿素a的相关性极显著 ,而丰水期则无明显相关性。NO3 N是水体无机氮的主要组成部分 ,平均占DIN的 72 6 % ,而水库的NH3 N含量明显低于NO3 N ,平均占DIN的2 5 5 %。NO2 N的含量一般很低。水库的总氮、DIN和有机氮含量是判断水库营养状态的重要指标 ,而NO3 N和NH3 N在DIN中所占比例则是推测污染物来源的重要依据     

连续可调式沉水植物网床对河道水质的修复

在太湖贡湖水源保护区陆域的一条长约200 m的污染河道内构建了一系列连续可调式沉水植物网床,形成了以菊花草、苦草、伊乐藻、轮叶黑藻和菹草等沉水植物构成的水生植物群落;跟踪监测了总氮(TN)、铵态氮(NH4 +-N)、亚硝态氮(NO2--N)、硝态氮(NO3--N)、总磷(TP)和磷酸盐(PO43--P)等水质指标,分析沉水植物网床引导沉水植被恢复对污染河道的水质修复效果.结果表明:沉水植被网床构建后,水体透明度显著升高,由修复前的0.5m提高到1.7 ～1.8 m;在沉水植被网床构建后的第5天和第20天,TN和TP的削减率分别为35.6％、66.3％和29.4％、63.2％;5个月后,修复河道水体内NH4+-N、NO2--N、NO3--N、TN、PO43--p和TP的浓度比对照组显著降低,削减率分别达到92.4％、76.8％、72.7％、73.9％、90.5％和92.0％.由连续可调式沉水植被网床引导恢复的水生植物群落可用于河道,特别是陆域浅水污染水体的生态修复.     

氮磷营养因子对赤潮异弯藻生长的影响

研究了N、P营养浓度对赤潮异弯藻(Heterosigma akashiwo)生长的影响.结果表明,该藻的生长速率与N、P营养因子浓度的关系符合Monod公式.在NO₃^--N浓度达到7.5 mg·L^-1时,赤潮异弯藻开始生长;浓度为3.75～75 mg·L^-1时,赤潮异弯藻的比生长速率与NO₃^--N浓度成正比关系.N营养充足时,赤潮异弯藻的最大生长速率μ_m-n=0.3475·d^-1,K_s-n=18.91 mg·L^-1.PO₄^--P浓度为0～1.0 mg·L^-1时,赤潮异弯藻的比生长速率与P浓度成正比关系;P营养充足时,赤潮异弯藻的最大生长速率μ_m-p=0.3024·d^-1,K_s-p=0.4086 mg·L^-1.N/P达到25后藻细胞浓度达到最大,表明N/P为25时最适合赤潮异弯藻生长.赤潮异弯藻最适合在N 37.5～225.0 mg·L^-1、P 5.0～50.0 mg·L^-1、N/P=25条件下生长.     

Influence of nitrate and COD on phosphorus, nitrogen and dinitrotoluene (DNT) removals under batch anaerobic and anoxic conditions

In this study, the effects of COD to NO(3)-N ratio in the feed on PO(4)-P removal was investigated. Maximum PO(4)-P uptake was obtained in the anoxic reactor when the COD to NO(3)-N ratios were between 2 and 3.75. With the influent COD of 800-1500 mg COD/L a total of the maximum removable PO(4)-P was 56 mg PO(4)-P/L through 20 days of anaerobic/anoxic incubation, indicating 98% P removal in the anoxic reactor. Similarly, for the COD to NO(3)-N ratios varying between 2 and 3.75 maximum denitrification was observed. Through anoxic operation the poly-P bacteria are capable of removing NO(3)-N using VFA, COD as carbon source and NO(3)-N as the electron acceptor after methanogenesis has been completed. High NO(3)-N concentrations stopped significantly the P uptake. A total of 97-99% dinitrotoluene removal efficiencies in the reactors containing COD to NO(3)-N ratio of 2 and 3.75 after 20 days of incubation period. For maximum NO(3)-N and PO(4)-P removals optimal COD to NO(3)-N ratios, COD and NO(3)-N concentrations were 2-3.75, 2000-4000 mg COD/L and, 800-1500 mg NO(3)-N/L, respectively.     

Ammonia-nitrogen and orthophosphate removal by immobilized Scenedesmus sp. isolated from municipal wastewater for potential use in tertiary treatment

Scendesmus sp. isolated from municipal wastewater, entrapped in calcium alginate as algal sheets was employed to remove inorganic nutrients (N and P) from artificial and real domestic secondary effluents in parallel-plate bioreactor after starvation. The key factors affecting the removal efficiency (NH4+-N and PO4(3-)-P), system stability and reuse efficiency of screens were studied and discussed. It has been shown that cell density in the mixture of algal gel was the key factor compared with the thickness of the gel and the cell density of the reactor. A complete removal of NH4+-N and PO4(3-)-P was achieved within 4h of treatment in parallel bioreactors with the optimal cell density in the mixture of algal (2 x 10(8) algae mL(-1)) and 3mm gel sheets after second cycle. Nine cycles of wastewater treatment in 21 days were accomplished, holding higher removal efficiency. NH(4)(+)-N removal efficiency was 99.1% after 105 min, 100% after 135 min, PO4(3-)-P removal efficiency was 100% after 15 min in domestic secondary effluents. Immobilized Scendesmus sp. is shown to have great potentialities for removal of inorganic nitrogen and phosphorus from treated effluents.     

Growth of Dalbergia sissoo in desert regions of western India using municipal effluent and the subsequent changes in soil and plant chemistry

Increasing demand for fodder and fuelwood and the scarcity of a good quality water in arid areas has resulted in a search for an alternative source of water for biomass production. An experiment utilizing municipal effluent in growing Dalbergia sissoo was conducted. Five treatments included T1, municipal effluent at 1 PET (Potential evapo-transpiration) (without plant); T2, municipal effluent at 1/2 PET; T3, municipal effluent at 1PET; T4, municipal effluent at 2 PET; and T5, canal water at 1 PET. Observations included plant height, collar diameter at one-month intervals and plant mineral composition, mineral uptake and changes in soil properties at 24 months of plant age. Application of municipal effluent produced better growth in D. sissoo seedlings. Concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn) were greater in seedlings irrigated with municipal effluent than those of the seedlings irrigated by the treatment T5, and positively related with the quantity of irrigation. The concentrations were greatest in foliage compared to the other parts of seedling, with the exception of Cu concentration. Application of municipal effluents resulted in a 2- to 3-fold increase in the concentrations of soil K, Cu, Fe, Mn and Zn, whereas NH4-N and PO4-P availability increased by 8.1- and 4.5-fold, respectively. The increase in soil organic carbon was only observed in treatments T3 and T4. The accumulations of soil NO3-N, Na, Cu, Fe, Mn and Zn were more in lower soil layers but the other soil parameters showed their greatest values in the upper soil layer. Irrigation using municipal effluent did not result in toxicity to the seedlings before the age of 24 months. The results suggest that municipal effluent could be utilized, as an important source of water and nutrients in growing D. sissoo to increase biomass production in the needs of suburban dwellers. However, a preliminary treatment to reduce excess NH4-N and PO4-P will be required before application to the plantation.     

不同基因型水生植物对铵态氮和硝态氮吸收动力学特性研究

针对不同营养状况的富营养化水体修复而选择吸收养分效率较强的水生植物,采用改进常规耗竭法比较研究了6种不同基因型水生植物凤眼莲(Eichhornia crassipes Solms)、黄花水龙(Jussiaea stipulacea Ohwi)、再力花(Thalia dealbata Fraser)、美人蕉(Canna glauca L.)、水芹[Oenanthe javanica(Bl).DC]和豆瓣菜(Nasturtium officinaleR.Br.)对铵态氮和硝态氮吸收动力学特性。结果表明,不同基因型水生植物吸收铵态氮和硝态氮的动力学特性可用Michaelis-Menten方程来描述。在低浓度培养下,不同基因型水生植物对NH4+-N和NO3--N吸收的动力学参数Imax和Km差异较大,其吸收NH4+-N和NO3--N的Imax最大是水芹,其次是豆瓣菜;Km值最小的是水芹,其次是豆瓣菜;且水芹对NH4+-N和NO3--N不仅具有较强的亲和力,还具有较高的离子吸收速率。结果还表明,当介质中氮浓度较低时,水芹有优先吸收硝态氮的趋势,而豆瓣菜和再力花有优先吸收铵态氮的趋势。     

Effect of carbon source on biological nutrient removal in a sequencing batch reactor

Sequencing batch operation was used for nutrient (COD, NH4-N, NO3-N, PO4-P) removal from synthetic wastewater by using different carbon sources. Operation consisted of anaerobic, anoxic, oxic, anoxic and oxic (An/Ax/Ox/Ax/Ox) phases with durations of 2/1/4.5/1.5/1.5 h. Glucose, acetate and a mixture of glucose/acetate were used as carbon source to yield a COD/N/P ratio of 100/5/1.5 in the feed. Sludge age was kept constant at 10 days. COD, NH4-N, NO3-N and PO4-P removal efficiencies were maximum at the levels of 96%, 87%, 81% and 90% respectively, when a mixture (50/50) of glucose and acetate was used.     

江西省余江县水体营养状况分析

用营养状态指数法(TSI)对江西省红壤区余江县东塘、五湖、仙塘三个水库的水质状况进行综合评价,结果表明三个水体的水质状况均呈富营养态。在此基础上对三个水库的10项主要水化学指标进行主成分分析,表明亚硝态氮和氨氮对第一主成分的贡献最大,COD为第二主成分的主要贡献者;而且三个水库的水质受水中有机物含量的影响最大,这一结果与当地的农业结构密切相关。     

垂直流人工湿地的设计及净化功能初探

阐述了垂直流人工湿地小试系统的设计,并测试其冬季污水净化效果,垂直流人工湿地由下地流和上行流方式的两池组成,对受污染地面水体中的CODCr,BOD5和TSS的去除率分别为53．6％,78．7％和80．2％,对细菌,总大肠菌,粪大肠菌和藻类的平均去除率分别达99．4％,85．9％,89．7％和97．7％,。对KN,HN4^ -N和TP的平均去除率分别为39．2％,16．5％和25．8％,各系统对污染物的去除作用无明显差异。系统出水NO3^-N浓度高于进水,而有植物系统中又高于无植物的对照,表明湿地植物的存在有利于硝化,表明下行流－上行流人工湿地在冬季仍能较好地改善水质,是一种有效的水处理技术,对水体水质改善和水生态系恢复具有重要意义。     

退化草地恢复过程中土壤氮素状况以及与植被地上绿色生物量形成关系的研究

 研究了在不同放牧率下形成的不同退化阶段的草地各形态氮素（全氮、硝态氮、铵态氮、无机氮和微生物氮）的变化情况,同时也研究了植被地上绿色生物量与各形态氮素季节变化的同步性关系。土壤全氮含量相对稳定,随草地植被状况和植物生长时期变化不大,说明土壤总氮库有相当的弹性。土壤硝态氮（NO－3-N）、铵态氮（NH+4-N）、无机氮（IN）和微生物氮（Micro-N）季节变化明显。土壤Micro-N和NO-3-N含量随植物生长逐渐降低,到植物枯黄期含量又回复到较高的水平;土壤NH+4-N含量随植物生长有逐渐升高的趋势;IN则随着植物的生长出现低-高-低-高的特点,且与植被地上绿色生物量呈显著负相关（R=-0.247, p<0.01）。在放牧条件下草原植物优先利用NO－3-N,NO－3-N与植被地上绿色生物量有显著的负相关性,是形成草原植被地上绿色生物量的有效性氮素。Micro-N能解释土壤IN 22.3%的变异（R2=0.223, p<0.01）,Micro-N是土壤无机氮的重要来源。土壤NH+4-N与Micro-N呈显著负相关（R=-0.222, p<0.01）,说明土壤微生物对土壤NH+4-N有偏好吸收。总体上,不同形态的氮素在各土壤层次间差异显著,随土壤层次的加深含量逐步降低。连续放牧11年恢复两年后,各氮素组分对放牧压力消除的响应并不一致。土壤全氮含量与停止放牧前相比变化差异不显著;而Micro-N对放牧压力消失的响应在不同处理下整个生长季的结果比较一致,即以前过度和中度放牧处理的Micro-N含量较高,无牧和轻牧含量较低;IN、NH+4-N和NO－3-N变化比较复杂,在不同放牧恢复处理上结果并不一致。总的来看,以前中度和过度放牧的IN、NH+4-N和NO－3-N含量较高,存在潜在损失的可能。经过两年的恢复,植被地上绿色生物量（8月）过牧处理与无牧处理差异不显著。     

华南赤红壤无机复合肥氮磷淋失特征

采用室内土柱淋溶模拟试验,研究了不同施肥水平下无机复合肥中氮和磷在华南赤红壤中的淋失特征.结果表明: 铵态氮、硝态氮和总氮淋失量均随施肥量增加而提高;肥料中氮的淋失率在36.8%～49.2%之间,总氮淋失量（y）与施肥量（x）之间的回归方程为y=0.3667x+66.483（R²=0.992）;铵态氮和总氮的淋失主要集中在前5次淋洗,硝态氮的淋失持续时间更长.施肥量对可溶性磷淋失量无显著影响,但颗粒磷和总磷淋失量均随施肥量增加呈上升趋势;肥料磷淋失率在0.002%～0.010%之间,总磷淋失量（y）与施肥量（x）之间的回归方程为y=7e^-5x+0.0538（R²=0.931）;磷的淋失动态与氮显著不同,为缓慢的持续累积过程.硝态氮与铵态氮淋失量比值和可溶性磷与颗粒磷淋失量比值均随施肥量增加呈下降趋势.     

Intermittent cyclic process for enhanced biological nutrient removal treating combined chemical laboratory wastewater

The aim of this work was to assess the efficacy for simultaneous enhanced removal of nitrogen and phosphorus including organics treating combined wastewater generated from a chemical laboratory using a bench-scale Intermittent Cyclic Process Bio-reactor (ICPBR). The performance efficacy indicated that the ICPBR system with solid retention time of 15 days achieved optimum efficiency with an overall removal of ammonia nitrogen (NH4-N), phosphorus (PO4-P), and chemical oxygen demand (COD) in the range, 83-92%, 74-93%, and 90-96%, respectively.