地下渗滤系统处理生活污水中浓度去除率与系统去除率对比研究

通过在试验场建立地下渗滤系统装置,系统在运行达到熟化后,应用其处理生活污水,水力负荷为1.8 cm/d。结果表明,地下渗滤系统对COD、氨氮、总氮的平均浓度去除率分别为87.9%、98.3%、42.9%,平均系统去除率分别为92.3%、98.9%、62.9%。其中,出水COD、氨氮、总氮的平均浓度分别为16.8、0.41、32.78 mg/L。各指标系统去除率都大于浓度去除率,说明系统去除率比浓度去除率更能精确表示地下渗滤系统处理生活污水的能力,尤其是对总氮的去除率更高。     

浸润线高度对垂直潜流湿地处理效果的影响研究

针对污染物浓度较高的猪场沼液,开展了不同浸润线高度下垂直潜流湿地处理效果的对比研究。试验结果表明:湿地浸润线可改变湿地填料层中的溶解氧分布和水力流态,从而造成了3种类型湿地系统对猪场沼液处理效果的差异;在不同水力负荷下,中浸润线垂直潜流湿地(VSSF-M)对猪场沼液中各项污染物的去除效果均好于低浸润线垂直潜流湿地(VSSF-L)和高浸润线垂直潜流湿地(VSSF-H);中浸润线垂直潜流湿地利用溶解氧梯度在填料层内实现了好氧区、缺氧区和厌氧区的共存,从而使硝化作用与反硝化作用在同一系统内完成,提高了系统的脱氮能力;中浸润线垂直潜流湿地系统还可适当增大系统的水力停留时间(HRT),并可优化水力流态,从而进一步改善湿地系统的净化效果。因此,结合处理效果和出水水质的稳定性,中浸润线垂直潜流湿地对浓度较高的猪场沼液具有较高的去除效率。     

工艺参数对蚯蚓生态滤池净化养殖污水的影响

[目的]探讨蚯蚓添加量、布料强度和布料方式等工艺参数对蚯蚓生物滤池净化养殖污水的影响特征,确定滤池规模化处理畜禽养殖污水的最佳条件,为养殖污水处理提供技术支撑.[方法]采用蚯蚓生态滤池技术净化养殖污水,测定水样中的总氮(TN)、氨氮(NH4+-N)、硝氮(NO3--N)、总磷(TP)、磷酸盐(PO43-)、化学需氧量(COD)、pH和电导率(EC)等指标.[结果]在相同蚯蚓添加量和滤料总量下,单层生态滤池去除养殖污水中TN、NH4+-N、NO3--N和COD的效果优于双层,但去除PO43-的效果劣于双层;布料强度为2.25~4.50 m3/m2·d时,最有利于养殖污水中NH4+-N、TN、TP和COD的去除,但对NO3--N含量、pH和EC变化无明显影响;蚯蚓添加量为0.5 kg/箱的处理对进水TN、NO3--N、NH4+-N、TP、PO43-和COD的平均去除率明显小于投入量1.0~2.0 kg/箱的处理,但蚯蚓添加量过大会导致出水EC增加.[结论]蚯蚓生态滤池能够持续高效并相对稳定地去除养殖污水中氮、磷和碳等污染物质.综合成本和效率因素,蚯蚓生态滤池净化养殖污水工艺建议采用单层布料,布料强度4.50 m3/m2·d,蚯蚓添加量1.0 kg/箱.     

水解-复合潜流人工湿地对农村生活污水脱氮研究

研究了水解池-垂直潜流-水平潜流人工湿地系统对云南省普洱市农村生活污水的处理,探讨了该系统对生活污水中CODCr、NH4+-N、NO3--N、TN的去除效果,并将水解池部分与湿地部分的处理效果进行了比较。结果表明,该系统对CODCr、NH4+-N、NO3--N、TN的总平均去除率分别为78%、89%、51%、85%,出水浓度分别<46、3.9、3.8、5.8 mg/L,达到了国家城镇污水处理厂污染物一级A类排放标准(GB18918-2002)。该系统对农村生活污水的处理效果较好,建设运行成本低廉,维护管理方便,适合农村地区生活污水处理的运用与推广。     

Nitrogen Use Efficiency as Affected by Phosphorus and Potassium in Long-Term Rice and Wheat Experiments

Improving nitrogen use efficiency （NUE） and decreasing N loss are critical to sustainable agriculture. The objective of this research was to investigate the effect of various fertilization regimes on yield, NUE, N agronomic efficiency （NAE） and N loss in long-term （16- or 24-yr） experiments carried out at three rice-wheat rotation sites （Chongqing, Suining and Wuchang） in subtropical China. Three treatments were examined： sole chemical N, N＋phosphorus （NP）, and NP＋potassium （NPK） fertilizations. Grain yields at three sites were significantly increased by 9.3-81.6% （rice） and 54.5-93.8% （wheat） under NP compared with N alone, 1.7-9.8% （rice） and 0-17.6% （wheat） with NPK compared with NP. Compared to NP, NUE significantly increased for wheat at Chongqing （9.3%） and Wuchang （11.8%）, but not at Suining, China. No changes in NUE were observed in rice between NP and NPK at all three sites. The rice-wheat rotation＇s NAE was 3.3 kg kg1 higher under NPK than under NP at Chongqing, while NAE was similar for NP and NPK at Suining and Wuchang. We estimated that an uptake increase of 1.0 kg N hal would increase 40 kg rice and 30 kg wheat ha-1. Nitrogen loss/input ratios were -60, -40 or -30% under N, NP or NPK at three sites, indicating significant decrease of N loss by P or PK additions. We attribute part of the increase in NUE soil N accumulation which significantly increased by 25-55 kg ha-1 yr1 under NPK at three sites, whereas by 35 kg ha-1 yr-1 under NP at Chongqing only. This paper illustrates that apply P and K to wheat, and reduce K application to rice is an effective nutrient management strategy for both the NUE improvement and N losses reduction in China.     

啤酒废水作为A~2/O工艺外加碳源的可行性研究

[目的]研究啤酒废水作为外加碳源下A2/O工艺的脱氮除磷效果。[方法]采用A2/O工艺处理模拟生活污水,以啤酒废水作为外加碳源,分析了投加啤酒废水对反应系统内总氮和PO43--P的去除率以及对COD、pH的影响。[结果]不同啤酒废水投加量下系统的脱氮除磷效果差异较大;在一定范围内,随着啤酒废水投加量的增大,总氮去除率增高,当啤酒废水投加量过大时,总氮去除率下降,而PO43--P的去除率随着啤酒废水投量的增大呈下降趋势。[结论]适当投加啤酒废水可以提高A2/O工艺的脱氮除磷效果,且较佳投量为70 mg/L。     

A/O-MBR工艺不同污泥停留时间下脱氮效能的分析

采用缺氧/好氧膜生物反应器(A/O-MBR)工艺处理模拟生活污水,考察了不同污泥停留时间t.(10、30、60 d)下反应器的脱氮效能.在A/O-MBR工艺中,tsr对化学需氧量和NH+4-N的去除效果无显著影响,化学需氧量平均去除率在95.4％以上,NH+4-N去除率在98.0％以上,出水化学需氧量与NH+4-N质量...     

Composition of Pig Manures and Wastewaters under the Gan Qing Fen System in China

A large scale pig farm located in the North West of Beijing that applies the gan qing fen manure management system was selected and a continuous sampling of manures and wastewaters was performed from June to October 2009. Samples were collected once a week based on the pig production cycle, namely gestation, farrowing, weaning and fattening. Analysis of nutrients and heavy metals were determined by means of Inductively Coupled Plasma Atomic Emission Spectroscopy （ICP）. Total Nitrogen （TN） was determined by the Kjeldahl method. The main results showed that pig manures were characterized by high nutrients and heavy metals contents that might be due to the solid fraction separation from the liquid fraction under the gan qing fen manure management system. Further, piggery wastewaters were characterized by very low concentrations of nutrients and heavy metals as result of their dilution with flushing water mainly used for cleaning the pigsties. Manure and wastewaters samples from weaning pigs contained the highest concentrations of nutrients and heavy metals that could be due to high supplementation rates of these minerals in the weaner diets. In general, it seems that the manual daily collection of pig manures in the gan qing fen system is an efficient practice in order to maintain nutrient contents in pig manures but the use of flushing water should be reduced as it can lead to further environmental pollution.     

人工快速渗滤法处理干旱区小城镇污水的试验研究

人工快速渗滤法作为一种处理效率较高、处理成本较低、运行维护技术要求低的分散式污水处理技术,比较符合小城镇污水处理需求。针对西北干旱区小城镇水环境污染日益严重,利用模拟系统研究了不同填料比和不同湿干比对人工快速渗滤系统处理小城镇污水时COD、总磷、凯氏氮和铵氮去除效果的影响。结果表明,土砂比2∶1的系统污染物去除效果优于其他填料比,对COD、总磷、凯氏氮和铵氮的去除率分别为35.05%～65.07%、53.27%～70.38%、10.42%～49.65%和11.61%～50.27%。COD、凯氏氮和铵氮的去除率在湿干比1∶1时最高,分别为27.86%～65.07%、49.65%～53.18%和50.27%～57.14%。在湿干比1∶5时,总磷的最高去除率为45.37%～69.15%。     

Effects of Nitrogen Sources on Nitrate Reductase Activity and Some Physiological Parameters in Psyllium （Plantago ovata F.） under Salinity Stress

The effects of three nitrogen sources （ammonium, nitrate and ammonium＋nitrate） and three salt treatments （0, 100 and 200 mM NaCl） on nitrate reductase activity, proline, soluble protein and carbohydrate contents in psylliom （Plantago ovata） plants were Studied. The nitrate reductase activity tended to increase when NO3- was included in the root-zone solution, but decrease as salinity increased. All N sources stimulated plant growth and nutrient uptake. Shoot and root dry matter tended to decrease as salinity increased, but less so when both NH4＋ and NO3- were present. Shoot biomass accumulated to significantly greater quantities under the mixed-N treatments than when produced using either NH4＋ or NO3- N-form alone. Although not statistically significant, the root biomasses showed a similar tendency. Generally, leaf proline and soluble shoot carbohydrate contents increased with increasing salinity in contrast to soluble protein which decreased regardless of the N source. Under salinity conditions, the concentration of Na＋ in shoot and root tissues was highest in ammonium-N treatment, while that of K＋ was highest in the mixed-N treatment.     

Analysis of Soil Water Dynamics in a Tropical Rain Forest Soil （Arinic lixisol）, Abeokuta,Nigeria

Soil water dynamics in the dominant lwo soil series （Arinic lixisol） were evaluated at the Federal University of Agriculture, Alabata, Abeokuta, Nigeria. Field capacity, infiltration and water retention characteristics were evaluated in situ for a period of 161 d in the dry season for two root zone depths. Results show that the Iwo soil series has a field capacity ranging from 2.6%-5.5% at 0-45 cm and 45-90 cm root zone depths, respectively. The soil is quick draining with high infiltration rate and very poor water retention capacity confirming that the soil will require a short irrigation interval of about 2-3 d since available water for plant growth in predominantly sandy soils ranges between 2%-8%. Based on the foregoing, sprinkler irrigation is best suited for the lwo soil series, it should, however, be noted that the water application rate must be less than the infiltration rate of the soil in order to prevent surface ponding and runoff. A multivariate model relating soil moisture content with soil moisture tension and soil temperature calibrated within the study had very low model accuracy of 56% and 45% for the two root zone depths, respectively, implying the need for further studies.     

Influence of Cropping Systems on Soil Properties in Semi-arid Conditions of Setif, Algeria

The effects of two culture systems, conventional and no-till combined the previous crop （lentil and wheat） on soil properties were studied in the experimental site of the station Technical Institute for Field Crops （ITGC） Setif （Algeria） during the crop year 2011/2012. The results indicate that the no-till system affects positively the variables of soil properties and the organic matter has a rate of 2.89% compared to 2.44% in conventional tillage. If the conventional system has an infiltration of moisture relatively higher than that observed for no-till throughout the cycle, the no-tillage is distinguished by a higher storage of moisture at the end of cycle wheat cultivation. The results also indicate that the density （1.44 g/cm）, permeability （22.79 cm/h） and soil compaction （12.51 kg/cm） in no-till were significantly higher compared to conventional tillage 1.35 g/cm, 14.13 cm/h, 7.40 kg/cm, respectively.     

Nitrogen Nutrition Index and Its Relationship with N Use Efficiency,Tuber Yield,Radiation Use Efficiency,and Leaf Parameters in Potatoes

Knowledge about crop growth processes in relation to N limitation is necessary to optimize N management in farming system. Plant-based diagnostic method, for instance nitrogen nutrition index （NNI） were used to determine the crop nitrogen status. This study determines the relationship of NNI with agronomic nitrogen use efficiency （AEN）, tuber yield, radiation use efficiency （RUE） and leaf parameters including leaf area index （LAI）, areal leaf N content （NJ and leaf N concentration （N0. Potatoes were grown in field at three N levels： no N （N 1）, 150 kg N ha^-1 （N2）, 300 kg N ha^-1 （N3）. N deficiency was quantified by NNI and RUE was generally calculated by estimating of the light absorbance on leaf area. NNI was used to evaluate the N effect on tuber yield, RUE, LAI, NAL, and NL. The results showed that NNI was negatively correlated with AEN, N deficiencies （NNI〈 1） which occurred for N 1 and N2 significantly reduced LAI, NL and tuber yield; whereas the N deficiencies had a relative small effect on NAL and RUE. To remove any effect other than N on these parameters, the actual ratio to maximum values were calculated for each developmental linear relationships were obtained between NNI and tuber RUE to NNI. stage of potatoes. When the NNI ranged from 0.4 to 1, positive yield, LAI, NL, while a nonlinear regression fitted the response of     

Revising Nitrogen Recommendations for Wheat in Response to the Need for Support of Variable-Rate Nitrogen Application

Sampling studies in North Dakota conducted from 1994 to 2003 showed that variable-rate N application could be practically directed with zone soil sampling. Results from variable-rate N studies using zone soil sampling were often less than rewarding due in part to the use of a whole-field predicted yield-based formula for developing the N recommendation in each zone. Nitrogen rate studies on spring wheat and durum were established in 2005 through 2009 with the objective to reexamine N recommendations and construct a new system if necessary. The results of the study and archived wheat N response data showed that the state should be divided into three separate N response regions. Within each region historic yields from low to high productivity were defined. The gross N rate was determined using the return-to-N concept developed in the US corn-belt states but with additional consideration for wheat protein value The gross N rate is then modified by credits for previous crop, soil test N from zone soil sampling, tillage systems, excessive straw from the previous year, relative susceptibility to nitrate leaching or denitrification. Finally, the user is encouraged to use common sense and consider whether particular fields have characteristics that require more or less N fertilizer than suggested by the recommendation formulas.     

低碳氮比污水中氨氮降解动力学研究

低碳氮比废水给氨氮的无害化处理带来困难,脱氮所面临的主要问题是如何以最低的代价提高其总氮去除率,试验通过驯化低碳比的活性污泥,驯化后活性污泥处理人工配制生活污水,探讨了基质降解动力学方程。结果表明:相同C/N比的污水,氨氮浓度的增加,去除率逐渐减少,氨氮浓度为26.3 mg/L时,仅运行4 h,氨氮的去除率就达到了99.5%,当氨氮浓度增加到106.7 mg/L时,运行7 h氨氮去除率仅为46.9%,但经过一个运行周期(12 h),氨氮去除率最终达到95%以上,氨氮降解过程符合Monod一级动力学方程SeS0=e-KXt;拟合曲线的相关指数R为-0.943 3~-0.983 2。保持氨氮浓度不变,提高有机物浓度,使其C∶N比的控制在2∶1、4∶1、6∶1、8∶1、10∶1,可以看出随着有机物浓度的增加,氨氮的降解速率逐渐加快,当C∶N增加到8∶1后,再加大有机物的浓度,对氨氮的降解速率基本没有影响。     

好氧颗粒污泥处理高氨氮养殖废水的试验研究

[目的]探寻好氧颗粒污泥处理高氨氮养殖废水过程中的影响因素,为工程实践提供理论依据。[方法]采用好氧颗粒污泥处理高氨氮猪场废水,研究化学需氧量（COD）、溶解氧（DO）和氨氮的去除率变化。[结果]在进水COD为1 000 mg/L,氨氮质量浓度为50mg/L的条件下,COD与氨氮的去除率均随处理时间增加而上升,但COD的去除效率远高于氨氮,处理4 h后,氨氮去除效率为55%,而COD去除效率接近90%。平稳运行下亚硝酸盐与硝酸盐浓度随时间的变化,始终稳定在较低的水平。[结论]采用好氧颗粒污泥处理高氨氮养殖废水具有良好的COD和氨氮去除效果,该技术值得推广。     

Effects of Nitrogen Application Rate and Ratio on Lodging Resistance of Super Rice with Different Genotypes

The objective of this study was to determine the morphology mechanism of nitrogen （N） fertilizer rates and ratio on lodging resistance through analying its effects among lodging index （LI）, lodging-related morphological traits and physical strength in basal intemodes by comparing japonica and indica super rice cultivars. Field experiments, with three nitrogen levels （0, 150 and 300 kg ha-L） and two ratios of basal to topdressing （8：2 and 5：5） with two super rice cultivars （Yliangyou 2 and Wuyunjing 23）, were conducted in the Baolin Farm, Danyang Country, Jiangsu Province, China, in 2011 and 2012. Effects of N fertilizer rates and ratios on morphology of whole plant, morphology traits in basal intemodes and culm＇s physical strength parameters were investigated at 20 d after full heading stage. LI of Yliangyou 2 was significant greater than that of Wuyunjing 23 due to larger bending moment by whole plant （WP） with higher plant height and gravity center height. With higher volume of N fertilizer, LI of two super rice cultivars was increased conspicuously. However, no significant effect was detected with increase of panicle fertilizer ratio. The size of breaking strength （M） in basal intemodes was the key factor determining LI among N fertilizer treatments. Correlation analysis revealed that M value was positively related bending stress （BS） of Wuyunjing 23 and section modulus （Z） of Yliangyou 2, respectively. The higher N fertilizer levels induced reduction ofBS of Wuyunjing 23 due to weak culm and leaf sheath plumpness status and reduced Z of Yliangyou 2 owning to small diameter and culm wall thickness, consequently, influencing their M indirectly. These results suggested that breaking strength was the key factor influencing LI with increase of N fertilizer levels. However, the lodging-related morphology mechanism was different with genotypes. Culm wall thickness and diameter in basal internodes of indica super rice and culm and leaf sheath plumpness status of japonica super rice influenced breaking strength, as well as lodging index, respectively.     

铬在水平潜流和垂直流人工湿地中的形态转化和迁移

本研究以薏苡为湿地植物，构建了小型垂直流人工湿地（VC）和水平潜流人工湿地（HC），研究了不同水分管理对处理Cr⁶⁺废水时铬的迁移转化的影响。结果表明： Cr⁶⁺处理下，两种湿地的薏苡生长均受到了抑制，水平潜流人工湿地薏苡生长受抑制程度低于垂直流人工湿地。水平潜流人工湿地铬含量较高，而垂直流人工湿地易吸收的可交换态和碳酸盐提取态铬含量较高。基质的pH和Eh均随Cr⁶⁺浓度的增加而呈现减小趋势。垂直流人工湿地pH及Eh值均大于水平潜流人工湿地。与潜流人工湿地相关的酶活性相比，垂直流人工湿地可以增加基质中蔗糖酶活性，但Cr⁶⁺处理下脲酶活性却低于水平潜流人工湿地。高通量分析表明，不同处理下的两种人工湿地基质微生物群落存在显著差异，水平潜流人工湿地微生物更有利于将铬转化为难以利用的铬形态。水平潜流人工湿地对废水中的Cr⁶⁺有更好的去除能力。研究表明，水平潜流人工湿地有利于促进Cr⁶⁺转化为难以利用的铬形态，提高了人工湿地对污水中Cr⁶⁺的去除能力。     

Phytophthora Root and Crown Rot on Fruit Trees in Bulgaria

Phytophthora root and crown rot was found on the fruit trees in Bulgaria for the first time in the period 1998-1999. Monitoring of the disease spread from 2000 to 2007 points out incidence between 2 and 14 per cent, in some orchards and nurseries in the Southern part of Bulgaria. The following Phytophthora species were identified based on morphological and cultural characteristics, and temperature requirements： Phytophthora cactorum, Phytophthora citrophthora, Phytophthora drechsleri, Phytophthora cryptogea, Phytophthora hybrid specie and Pythium. Prevailing specie was P. cactorum. P. cryptogea and P. cactorum were confirmed by application of molecular methods. Nutritional requirements of P. cactorum and P. citrophthora were studied. Most Nitrogen sources stimulated the mycelial growth of P. cactorum to a higher extend, and reduced the colony size ofP. citrophthora. Different Carbon sources were utilized well by P. cactorum, and only saccharose and maltose had a stimulating effect on the mycelial growth of P. citrophthora. MgSO4.7H20 was the preferred sulfur source for both fungi, as L-cysteine and L-methionine only for P. cactorum. Phytophthora infection leads to physiological changes in the.host plant tissues. The tendency traced out is： about disorders in the amino acid metabolism, increase in the total sugars and slight reduction of the cellulose content. The total nitrogen, phosphorus and potassium content are reduced and the calcium and magnesium are increased. Photosynthesis of inoculated plants was suppressed and transpiration was increased.     

核桃壳用于氨氮废水处理的试验

将废弃生物质核桃壳改性后用于处理氨氮废水,比较了废水pH、改性核桃壳用量、废水中氨氮的初始浓度、接触时间等对氨氮去除效果的影响。结果表明,pH在3~9时,改性核桃壳去除废水中的氨氮比较合适,最大去除率可达81%;改性核桃壳处理氨氮废水(100 mg/L)采用10 g/L的用量比较合适;氨氮废水中氨氮的初始浓度对氨氮的去除有较大影响,当氨氮浓度增加到300 mg/L后,吸附量增加不再明显,吸附量可达9.3 mg/g;改性核桃壳处理氨氮废水的接触时间选择6.0 h比较合适。改性核桃壳处理氨氮废水主要以吸附为主,同时还有氧化还原的化学反应过程。