共查询到19条相似文献，搜索用时 140 毫秒
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小浮萍去除氮磷影响因素研究 总被引：1，自引：0，他引：1
以我国南方常见的小浮萍为供试材料,考察了光照时间、小浮萍初始生物量和培养液氮、磷浓度等因素对小浮萍去除氮磷的影响。结果表明:小浮萍对氮、磷的去除随光照时间的增加而增加;小浮萍初始生物量越大,污水氮、磷的去除率越高;培养液初始磷浓度升高,单位重量小浮萍对磷的吸收量增加;NO3-N浓度为0～60mg/L时,小浮萍对PO3-4P的去除率介于90%～95%之间;NO3-N浓度为0～10mg/L时,小浮萍吸收净化后试液NO3-N检不出。 相似文献
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钼酸铵浸种对不同氮源下鲜食油菜产量、品质及对氮磷钾吸收的影响 总被引：4，自引：0，他引：4
采用盆栽试验，研究了不同氮源条件下，钼酸铵浸种对油菜产量、品质及氮磷钾(NPK)吸收的影响。结果表明：NH4NO3 Mo对提高鲜食油菜的鲜重和干重具有显著作用；NH4Cl Mo对油菜Vc含量和叶绿素含量具有显著的提高作用，NH4NO3和(NH4)2SO4与钼配施效果不及NH4Cl。同一时期内的油菜植株Vc含量与叶绿素含量呈正相关；在NPK的吸收方面，不同种类氮肥的阴、阳离子与钼互作效应不同，硝酸铵与钼配施时，钼与NPK均表现协同作用，而NH4Cl和(NH4)2SO4与钼配施时，钼与氮、磷表现协同作用,而钼与钾表现拮抗作用。 相似文献
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堆肥化过程中氮素转化和NH3挥发研究 总被引：3，自引：0，他引：3
研究在猪粪、米糠强制通风堆肥过程中,堆体中氮素转化特点和NH3挥发规律.结果表明:堆肥过程,全氮(T-N)、有机氮含量先降低后被浓缩略有增加;水溶性NO3--N含量逐渐提高;而水溶性NH4 -N的含量先增加后减少.水溶性NH4 -N含量与堆体的pH值存在极显著的正相关(r=0.857 9**),表明降低堆体pH可抑制NH4 -N转化为NH3.此外,猪粪堆肥NH3产生和挥发损失的高峰期是在升温期和高温期(0~14d),说明堆肥前期是控制N素损失的关键时期.NH3挥发量与水溶态NH4 -N含量和pH值存在极显著和显著的正相关(r值分别为0.872 3**和0.785 7*).因此,降低堆体pH值、控制NH4 -N向其它形态氮转化是减少N损失的有效措施. 相似文献
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亚硝化-反硝化固定化细胞捷径生物脱氮的研究 总被引：1，自引：0，他引：1
选用聚乙烯醇(PVA)和海藻酸钠(CA)作为载体,添加适量SiO2粉末,将筛选出来的高效亚硝化细菌和反硝化细菌分别制成固定化细胞,联合进行脱氮实验.结果表明:按1:1的比例,亚硝化细菌和反硝化细菌固定化细胞接种量为15%(W/V),在温度为30℃,摇床转数为110rpm的条件下处理合成废水(NH4+-N=150mg/L,碱度(NaHCO3=1700mg/L,pH=8.0),27h,脱氮率为97.53%;处理富营养化水体(NH4+-N=34.26mg/L,pH=6.7),20h,脱氮率达到79.51%. 相似文献
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本文在以复合式膜生物反应器系统为基础,以模拟城市污水为处理对象。通过运行条件优化研究,综合脱氮除磷效果及经济因素,将复合区水力停留时间控制在7h左右。此时系统总去除率为:CODcr≧96.28%、NH3-N≧97.54%、TN≧74.87%、TP≧74.34%,出水可以稳定保证在CODcr≦14.35mg/L、NH3-N≦0.74mg/L、TN≦9.02mg/L、TP≦1.05mg/L。效果较好。 相似文献
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采用溴百里酚蓝（BTB）选择性培养基对采集样品进行初筛分离。初筛菌株在30℃,DM培养基培养3天后的溶液测定其TN、NO3-N、NO2-N浓度变化。最终成功分离得到一株编号为8#菌株对NO3-N的降解率91．70％,亚硝态氮累积量仅为0．61mg·L-1。该菌株反硝化能力较强,在实际的废水处理中具有一定的应用价值。 相似文献
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在循环活性污泥系统内投加聚丙烯多面空心球填料而组建为填料-悬浮活性污泥系统,针对某生物化工废水进行该系统启动期研究。结果表明,随着填料上生物膜的增加,系统对COD和NH4+-N的去除效果越来越好,挂膜基本成熟后,系统出水COD在80mg/L左右、NH4+-N在1mg/L左右,两个考察指标均能满足排放(COD100mg/L,NH4+-N5mg/L)要求;填料的投加能够有效提高系统内生物量和生物种类,平均挂模量约为75.04mg/g,填料上出现大量活性良好的游离性纤毛虫、盖纤虫、轮虫等指示性微生物。因此,在CASS系统内投加生物载体填料来进行处理工艺升级改造是一个很好的手段。 相似文献
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A series of laboratory and pot experiments carried out to examine the role of soil microbial biomass in red soils' nitrogen availability and productivity showed that soil available N (NA), dry matter yield (DMY) of ryegrass, and plant uptake of nitrogen were each closely correlated with microbial biomass-C (Cmic) or -N (Nmic), suggesting that soil microbial biomass is a very important nitrogen pool available to plants in red soils. After correction for the substrate effect, the computed turnover of the Nmic in three tested soils ranged from 63 to 250 days. Soils with low Nmic or light texture generally had higher Nmic turnover rate than those with high Nmic or heavy texture. These results showed that soils with low Nmic, microbial biomass could also play an important role in the availability of nitrogen to plants due to these soils' high turnover rate. 相似文献
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NaCl胁迫对水稻（Oryza sativa）种子萌发和幼苗生长的影响 总被引：1，自引：0，他引：1
采用水培法,研究不同浓度（0、50、100、150、200、250、300、350、400、450、500mmol／L）的NaCl胁迫对水稻种子萌发,胚根、胚芽和幼苗生长的影响。结果表明：种子的发芽势、发芽率、都随着NaCl胁迫浓度的升高而降低,300mmol／L以上种子发芽率为0;胚根长,胚芽长也随着NaCl胁迫浓度的升高而降低,浓度大于100mmol／L时有显著（p〈0．05）影响。水稻幼苗的根长、株高、株鲜重、根干重以及茎干重也随NaCl胁迫浓度的升高呈逐渐降低的趋势,当浓度大于250mmol／L时影响尤为显著,大于300mmol／L时,植株严重失水,萎蔫,枯黄,死亡。研究结果说明NaCl胁迫对水稻种子的萌发和幼苗的生长有严重的抑制作用。 相似文献
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Ramesh Maheshwari 《Resonance》2006,11(4):33-44
The roots of most land plants establish intimate associations with soil fungi. This association of plant roots with fungi
is termed mycorrhiza. It is a marriage between two highly dissimilar organisms based on mutual exchange of nutrients: while
the plants provide photosynthetically made carbon compounds to the fungi, the fungi in turn provide to the plants nitrogen
and phosphorus scavenged from the breakdown of organic polymers in natural substrates. This mutually beneficial partnership
makes possible the green cover on Earth and of all life, ultimately, dependent on plants. 相似文献
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为了解汤河水体中污染物的变化特征,选取7个代表性取样点分季节进行2次水体采样,测定pH、氨氮、总氮、总磷及COD,并分析其成因.研究结果表明汤河水体pH整体上2月份较7月份略高,除取样点1、2外,其他各点2月份氨氮、总氮、总磷和COD都较7月份高. 可见,7月份汤河水质明显优于2月份,其原因可能与7月份水生植物生长旺盛,植物吸收了水体中的氮、磷等污染物,以及2月份水中植被死亡有机物的释放有关.此外,从汤河上游到下游水体污染物浓度呈现出明显上升的趋势,但不同取样点水体污染物浓度变化较大,氨氮、 总氮、 总磷及COD浓度变化幅度依次为0.052-0.32 mg/L 、0.075-0.41 mg/L、0.014-0.419 mg/L和11-31.7 mg/L,导致这种现象的原因可能与取样点周边城镇、农村生活污水、农业和工业废水的无序排放有关. 相似文献
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A field experiment was conducted to study the response of individual leaf spectral reflectance to five levels of nitrogen
fertilizer treatments in rice (Oriza sativa L.) plants. Sampling was combined through a rice canopy at upper, medium and low levels for biomass, nitrogen and water content
measurements with spectral signals from the leaves. The vertical gradients of leaf biomass, nitrogen and water contents were
associated with the nitrogen availability during tillering, panicle formation, initial heading and heading. Rice plants treated
with the lowest rate of N could be characterized with the lowest value of gradient in leaf biomass and leaf water content
and the highest value of gradient in leaf N concentration. A spectral gradient of single reflectance (R), ratio (RVI) and
normalized difference (ND) of two individual reflectances was defined as this yielded a better relationship between the spectral
data and leaf nitrogen concentration. The results suggested the spectral gradients may be used as an improved diagnostic tool
for nitrogen status.
Project (49771056) supported by Natural Science Foundation of China(NSFC). 相似文献
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The effect of Al and Cd on the growth, photosynthesis, and accumulation of Al, Cd and plant nutrients in two soybean genotypes were determined using hydroponic culture. There were six treatments: pH 6.5; pH 4.0; pH 6.5 1.0 μmol/L Cd; pH 4.0 1.0 μmol/L Cd; pH 4.0 150 μmol/L Al; pH 4.0 1.0 μmol/L Cd 150 μmol/L Al. The low pH (4.0) and Al treatments caused marked reduction in root length, shoot height, dry weight, chlorophyll content (SPAD value) and photosynthetic rate. Al-sensitive cv. Zhechun 2 accumulated comparatively more Al and Cd in plants than Al-tolerant cv. Liao 1. Compared with pH 6.5, pH 4.0 resulted in significant increase in Cd and Al concentration in plants. Combined application of Cd and Al enhanced their accu-mulation in roots, but caused a reduction in shoots. The concentrations of all 10 nutrients (P, K, Ca, Mg, Fe, Mn, Cu, Zn and B), except Mo were also increased when plants were exposed to pH lower than pH 6.5. Al addition caused a reduction in the con-centration of most nutrients in plant roots and shoots; but K, Mn and Zn in roots were increased. Treatments with Cd alone or together with Al reduced the concentrations of all the plant nutrients in plants. Al-sensitive genotype Zhechun 2 has lower nutrient concentration than Al-tolerant genotype Liao 1. The current findings imply that Al and Cd are synergistic in their effect on plant growth, physiological traits and nutrient uptake. 相似文献
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不同铵硝比的氮素营养对菠菜氮磷钾养分吸收影响显著。(1)铵硝比对于菠菜各部位含氮量的影响不大,随着铵硝比的下降,菠菜植株累积的氮素显著增加。(2)适当增铵有利于磷、钾的吸收和累积;铵硝比为25:75的处理,菠菜植株中磷、钾含量和累积量均最高。 相似文献