组合型生态浮床对水体修复及植物氮磷吸收能力研究

在天鹅湖水体中构建以水生植物和陆生喜水植物为实验植物,浮法控制器、水循环增氧系统和造浪-输送系统相集合的组合型生态浮床。在中试研究中,研究了其对天鹅湖上覆水和沉积物中营养物质的修复动态。结果表明,经过4个多月的组合型生态浮床生态修复,天鹅湖上覆水中TN、NH4+-N和TP的去除率分别达到61.92%、63.09%和80.0%,沉积物中TN和NH4+-N含量的去除率分别达到23.79%和37.04%,TP含量升高了43.71%;组合型生态浮床的5种浮床植物的氮磷累积量差异显著,再力花和美人蕉对氮磷的吸收速率显著高于菖蒲、薄荷和水稻,再力花和美人蕉对氮的吸收速率达到12.19 g/(m2.d)和7.90 g/(m2.d),对磷吸收分别达到0.81 g/(m2.d)和0.99 g/(m2.d)。美人蕉和再力花对氮磷的吸收量均是茎叶>根系,其中美人蕉茎叶氮、磷吸收量分别为根系的2.73倍和1.93倍,再力花分别为1.83倍和1.19倍,通过浮床系统植物水上部分的收割可以去除水体中的氮磷。     

北方景观水体中生态浮床的植物筛选与水质净化效果

以千屈菜(Lythrum salicaria L.)、黄菖蒲(Iris pseudacorus L.)、鸢尾(Iris tectorum Maxim.)3种植物为对象,研究了北京市朝阳区景观水体中生态浮床的植物筛选与水质净化效果。结果显示,千屈菜、黄菖蒲、鸢尾均生长迅速,且千屈菜表现最佳;移栽4个月后,3种植物的生物量分别较初始增加了15.9、8.5和13.1倍,达到945.5、489.2和585.0 g/m~2。千屈菜对水体氮、磷的吸收去除能力显著(P0.001)高于黄菖蒲和鸢尾,其总氮、总磷吸收量分别为黄菖蒲的2.2倍和2.3倍,为鸢尾的2.1倍和1.9倍。生态浮床的水质净化效果总体良好,运行60 d后,水体总氮、总磷浓度分别从16.28和0.27mg/L降低至5.70和0.18 mg/L,二者去除率分别为65.0%和35.0%。研究表明,千屈菜、黄菖蒲、鸢尾在营造景观和净化水质方面协同作用良好,其中千屈菜表现尤为突出,可作为北方地区生态浮床的首选植物。     

3种水生植物对富营养化水质的净化性能比较

选择芦苇、狐尾藻、菖蒲3种水生植物净化富营养化水体,考察了不同水生植物及组合对富营养化水体中硝酸盐氮、氨氮、TN、TP、COD、BOD5的去除效果。结果表明,菖蒲对氮、磷的去除效果明显优于芦苇和狐尾藻,狐尾藻在COD的去除上表现出一定的优势,而芦苇对BOD5的去除效果最加。在植物组合处理中,菖蒲+狐尾藻组合对氮、BOD5去除效果最佳,处理28d后,TN、BOD5去除率分别达80%、57%,芦苇+菖蒲组合对TP、COD去除效果优于其他组合,处理28d后,TP、COD去除率分别达87%、72%;处理过程中,狐尾藻生物量增长最多,且对芦苇、菖蒲具有明显的抑制作用,是3种植物中的优势物种。综合考虑水质净化效果及植物生长状况,菖蒲和芦苇可作为富营养化水体的净化植物,而狐尾藻则应该谨慎使用。     

人工湿地污水处理系统中的植物氮磷吸收富集能力研究

比较研究了人工湿地污水处理系统中7种植物对氮、磷的吸收能力.研究表明,所选7种湿地植物,稳定生长4个月后,平均总生物量在1 215～3 500 g/m2,植物氮、磷平均质量浓度分别为13.76～23.11、1.44～3.80 mg/g.香蒲具有最高氮积累量达48.18 g/m2,梭鱼草具有最高磷积累量为7.23 g/m2,姜草对氮、磷的积累量最低分别为21.40、1.68 g/m2.植物地上部氮、磷积累量与地下部的氮、磷积累量差异较大,除姜草外,植物地上部、地下部的氮、磷积累量比均大于3,黄花美人蕉地上部、地下部的氮、磷积累量比分别达11.75、12.10.通过植物收割去除氮、磷量约占湿地总去除量的2%～6%.     

川中丘陵区高富集氮、磷沟渠植物的筛选

选择7种川中丘陵区常见沟渠植物(酸模、菖蒲、黑麦草、水芋、美人蕉、水蓼、野薄荷)作为研究对象,盆栽试验研究了不同植物对氮、磷的吸收能力,以期筛选出适应川中丘陵区沟渠生长的高富集氮、磷植物。结果表明:(1)不同沟渠植物地上部生物量(以干质量计)为0.43~1.38kg/m2,其中美人蕉最大,菖蒲最小。(2)不同沟渠植物地上部全氮为4.50~14.35g/kg,其中水芋最高,水蓼最低;不同沟渠植物地上部全磷为0.80~2.15g/kg,其中水芋最高,野薄荷最低。(3)不同沟渠植物地上部全氮吸收量为2.88~15.66g/m2,其中美人蕉最高,其次为水芋;不同沟渠植物地上部全磷吸收量为0.48~2.04g/m2,其中美人蕉和水芋地上部全磷吸收量最高,水蓼、黑麦草和酸模次之,菖蒲和野薄荷最低。     

5种浮床植物对宁夏引黄灌区稻田退水中氮磷的去除效果

为了探索植物浮床技术应用和农业面源污染防治的有效措施,采用稻田退水沟渠原位实验,研究了美人蕉(Canna indica)、千屈菜(Lythrum salicaria)、黄菖蒲(Iris pseudacorus)、空心菜(Ipomoea aquatica)、水稻(Oryza sativa)5种不同浮床植物对退水中氮、磷的去除效果。结果表明,在稻田退水中生长4个月后,5种浮床植物生物量均大幅度增加。其中,美人蕉生物增长量最大,为97.2 g·株~(-1),其次为千屈菜达到81.3 g·株~(-1);空心菜成活率最高,达到91.67%,美人蕉其次,为87.50%,而水稻成活率最低,仅为60.71%;千屈菜茎叶和根系的氮含量最高,分别达到0.85%和0.65%;美人蕉茎叶、根系的磷含量最高,分别达到0.15%、0.17%;空心菜氮吸收量最高,达到14 239.46 mg·m~(-2),美人蕉其次,为10 798.00 mg·m~(-2);水稻磷吸收量最高,达到407.11 mg·m~(-2),空心菜其次,为374.41 mg·m~(-2);空心菜对稻田退水中总氮(TN)去除率最高,达到85.88%,其次为美人蕉,为81.67%;空心菜总磷(TP)去除率最高,达到80.32%,其次为水稻,达到72.86%。根据上述实验结果,推荐浮床空心菜和美人蕉作为宁夏引黄灌区农田排水沟水质改善的主要植物。     

人工湿地脱氮除磷特性研究

针对流域水体富营养化加剧和二级处理水氮磷指标较高的问题,提出以人工湿地对二级出水继续低耗、理想地脱氮除磷。研究中通过对照不同进水水质条件下,不同结构人工湿地的脱氮除磷效能,探讨了人工湿地内的主要脱氮除磷途径。研究表明,表面流湿地内植物对氨氮吸收／吸附和硝化过程为主要氮转化途径,潜流湿地内直接反硝化过程为主要脱氮途径,脱氮效率30％～40％;磷在人工湿地内主要依赖除磷填料床的物化吸附、共沉淀去除,除磷效率达80％以上。     

水生植物类型及生物量对污水处理厂尾水净化效果的影响

为阐明水生植物类型和生物量对污水处理厂尾水净化效果的影响,选取空心菜(Ipomoea aquatica Forsk)、苦草(Vallisneria natans L.)、粉绿狐尾藻(Myriophyllum aquaticum)3种水生植物对宜兴市周铁镇污水处理厂尾水进行净化。实验对不同植物分别设置4个生物量梯度以及无植物的对照组,考察不同植物和生物量对尾水净化效果的影响。结果表明:不同植物对污水处理厂尾水净化效果存在差异,总氮净化效果(30 d)受植物类型影响显著(P0.05)。粉绿狐尾藻对总氮和硝氮净化效果(30 d)最好,分别为95.28%和98.50%;苦草对氨氮和总磷净化效果(30 d)最好,分别为95.30%和95.80%,且苦草生长有利于降低亚硝氮的产生量。不同生物量对尾水净化效果影响较小,空心菜、苦草和粉绿狐尾藻去除总氮的最佳生物量分别为157.50、460.80和1 120.00 g,去除总磷的最佳生物量分别为157.50,609.40和590.00 g。不同生物量对空心菜生长存在影响,高空心菜生物量到后期会衰败,而低生物量处理组在实验周期内持续生长,造成高生物量净化效果低于低生物量,建议使用空心菜净化污水时,使用低生物量处理,且在其达到最大生物量(610.00~880.00 g)之前进行收割。     

人工浮床栽培7种植物在富营养化水体中的生长特性研究

本研究利用人工浮床在富营养化水体栽培了7种植物,成活率都在70%以上,2个月的生长期内生物的生长量都超过20kg鲜重/m2.浮床栽培芦苇的净化效果最好,每平方米的芦苇浮床可以使117.93 m3的水从V类水质净化为Ⅲ类水质(以总磷计),其次分别为荻、水稻、蕹菜、牛筋草、香蒲和美人蕉.对蕹菜和水稻植株的检测表明,分别作为蔬菜和青饲料完全符合国家有关卫生标准.     

不同氮磷比对多年生水生植物生长特性影响的研究

从氮、磷等植物生长的环境因子出发，研究了高低氮磷营养水平下，不同氮／磷比例的富营养化水体对聚草（Myriophyllum spicatum）、黄花水龙（Jussiaea stipulacea Ohwi）、喜旱莲子草（Alternanthera philoxeroides）生长特性的影响。结果表明，聚草在氮磷比2：1时生物量最大，且生物量在高浓度水平处理明显大于低浓度水平处理（P〈0．01）；黄花水龙在氮磷比10：1～20：1时生物量最大，高低浓度水平处理问生物量无显著性差异；喜旱莲子草在较高氮磷比20：l～40：1时生物量最大，高浓度水平处理时生物量显著性高于低浓度水平处理（P〈0．05）。在低浓度水平处理时，氮为黄花水龙和喜旱莲子草生长的主要限制因子，磷为聚草生长的主要限制因子，且喜早莲子草叶绿素增长期较其他处理提前，而黄花水龙的叶绿素变化在高低营养水平下差异不显著。营养盐水平对聚草茎长和生物量的影响较对黄花水龙和喜旱莲子草的影响明显。     

冬季生态浮床对浮游藻类数量及生物多样性的影响

为了考察生态浮床在冬季的运行效果,选择世博园区白莲泾生态浮床工程为研究对象,研究了冬季生态浮床对浮游藻类数量及生物多样性的影响。结果表明,取样期间浮游藻类生物总量逐月增加,且对照区明显高于浮床区;浮床区与对照区浮游藻类的种群结构差异明显,浮床区以硅藻门为主,而对照区以绿藻门为主。并且,小环藻与细微颤藻的优势度指数均有明显的下降。同时,浮床区的Shannon-Wiener多样性指数明显高于对照区。以上结果均证明,虽然在冬季较低温的情况下水生植物新陈代谢缓慢,但生态浮床仍会影响浮游藻类的数量及生物多样性,从而对水质净化起到一定的改善作用。     

Assessing nitrogen and phosphorus removal potential of five plant species in floating treatment wetlands receiving simulated nursery runoff

The feasibility of using floating treatment wetlands (FTWs) to treat runoff typical of commercial nurseries was investigated using two 8-week trials with replicated mesocosms. Plants were supported by Beemat rafts. Five monoculture treatments of Agrostis alba (red top), Canna × generalis ‘Firebird’ (canna lily), Carex stricta (tussock sedge), Iris ensata ‘Rising Sun’ (Japanese water iris), Panicum virgatum (switchgrass), two mixed species treatments, and an unplanted control were assessed. These plant species are used for ornamental, wetland, and biofuel purposes. Nitrogen (N) and phosphorus (P) removals were evaluated after a 7-day hydraulic retention time (HRT). N removal (sum of ammonium-N, nitrate-N, and nitrite-N) from FTW treatments ranged from 0.255 to 0.738 g·m^?2·d^?1 (38.9 to 82.4% removal) and 0.147 to 0.656 g·m^?2·d^?1 (12.9 to 59.6% removal) for trials 1 and 2, respectively. P removal (phosphate-P) ranged from 0.052 to 0.128 g·m^?2·d^?1 (26.1 to 64.7% removal) for trial 1, and 0.074 to 0.194 g·m^?2·d^?1 (26.8 to 63.2% removal) for trial 2. Panicum virgatum removed more N and P than any other FTW treatment and the control in both trials. Results show that species selection and timing of FTW harvest impact the rate and mass of nutrient remediation. FTWs can effectively remove N and P from runoff from commercial nurseries.

     

Direct Effects of Atmospheric Sulfate Deposition on Vegetation

Acid sulfate aerosol (500 μg/m³) had no effect on soybean or pinto bean after a single 4-h exposure. However, visible Injury and chlorophyll loss occurred when plants were sequentially exposed to acid aerosol and ozone (380 μg/m³) for 4 h. In yellow poplar seedlings exposed to ozone (200 μg/m³), sulfur dioxide (210 μg/m³) and simulated rain solutions (pH 5.6, 4.3 and 3.0) for 6 weeks, root dry weight, leaf area increase, mean relative growth rate and unit leaf rate decreased linearly with pH in ozone-treated plants. However, unit leaf rate and mean relative growth rate increased linearly in response to sulfur dioxide as solution acidity increased. Ambient wet and dry sulfate concentrations appear insufficient to directly impact vegetation.     

人工湿地植物泌氧与污染物降解耗氧关系研究

实验采用静态水培方法研究了香蒲(Typha orientalis)、芦苇(Phragmites australis)和水葱(Scirpus validus)3种常见湿地水生植物潜在泌氧能力、去污效果,并对水生植物泌氧量与污染物降解耗氧量进行了计算分析,从而阐明湿地植物泌氧与污染物降解耗氧之间的关系。结果表明,3种植物泌氧能力由大到小依次为:芦苇香蒲水葱,其中,芦苇比放氧速率、面积泌氧率均最高,分别为3.36 mg O2/(g.d)和4.35 g O2/(m2.d)。植物对湿地系统中污染物的去除有重要影响,各植物系统COD去除速率在3.46~3.77 g/(m2.d)之间;NH4+-N去除速率在0.07~0.13 g/(m2.d);TN去除速率在0.25~0.27 g/(m2.d);TP去除速率均为0.09 g/(m2.d);均好于无植物空白系统。计算表明,各植物体系泌氧量在0.48~0.55 g O2/d之间;各植物体系COD、NH4+-N耗氧量在0.41~0.46 g O2/d之间;植物净泌氧量在0.02~0.12 g O2/d之间。植物泌氧量与COD、NH4+-N耗氧量呈显著正相关关系。若应用人工湿地处理城镇生活污水,各植物体系COD最大去除负荷在3.81~4.35 g/(m2.d)之间,NH4+-N最大去除负荷在0.83~0.95 g/(m2.d)之间,最大水力负荷在1.65~1.89 cm/d之间。     

Nutrient stoichiometry in Sphagnum along a nitrogen deposition gradient in highly polluted region of Central-East Europe

We investigated the variation of N:P and N:K ratio in ombrotrophic Sphagnum plants along a gradient of atmospheric N deposition from 1 to 2.5 g m⁻² year⁻¹ in Central-East Europe. The N:P and N:K ratio in Sphagnum capitula increased significantly along the N deposition gradient. Sphagnum species from the Cuspidata section were characterised by significantly lower ratios at low N deposition. When we compared the observed N:P ratios in Sphagnum plants with the values reported in a previous European-wide study, we found a correspondence in nutrient stoichiometry only for a few bogs: higher P concentration in Sphagnum capitula caused a lower N:P ratio in most of the study bogs so that Sphagnum plants still seem N-limited despite their N saturation. Interaction between summer water table decrease and aerial liming of surrounding forests is proposed as an explanation for this discrepancy. Local forestry practice interacting with climate thus alter N:P stoichiometry of Sphagnum along the N deposition gradient.     

植物生态浮床的制备及其对富营养化水体的净化效果

针对福州市闽侯县旗山大学城景观湖某富营养化实验水区,制备了一种应用型植物生态浮床。原位修复结果表明,负载美人蕉(Canna coccinea Mill)的生态浮床对浮床周围的小生境有一定的修复效果;对美人蕉根际圈的微生物数量跟踪显示,在60 d内,微生物数量增加了2个数量级,微生物种类无明显变化,但不同植株根际圈的微生物种类存在一定差异。     

Effect of Cuscuta campestris parasitism on the physiological and anatomical changes in untreated and herbicide-treated sugar beet

The effects of field dodder on physiological and anatomical processes in untreated sugar beet plants and the effects of propyzamide on field dodder were examined under controlled conditions. The experiment included the following variants: N—noninfested sugar beet plants (control); I - infested sugar beet plants (untreated), and infested plants treated with propyzamide (1500 g a.i. ha^?1 (T₁) and 2000 g a.i. ha^?1(T₂)). The following parameters were checked: physiological—pigment contents (chlorophyll a, chlorophyll b, total carotenoids); anatomical -leaf parameters: thickness of epidermis, parenchyma and spongy tissue, mesophyll and underside leaf epidermis, and diameter of bundle sheath cells; petiole parameters: diameter of tracheid, petiole hydraulic conductance, xylem surface, phloem cell diameter and phloem area in sugar beet plants. A conventional paraffin wax method was used to prepare the samples for microscopy. Pigment contents were measured spectrophotometrically after methanol extraction. All parameters were measured: prior to herbicide application (0 assessment), then 7, 14, 21, 28 and 35 days after application (DAA). Field dodder was found to affect the pigment contents in untreated sugar beet plants, causing significant reductions. Conversely, reduction in the treated plants decreased 27% to 4% for chlorophyll a, from 21% to 5% for chlorophyll b, and from 28% to 5% for carotenoids (T₁). Also, in treatment T_2, reduction decreased in infested and treated plants from 19% to 2% for chlorophyll a, from 21% to 2% for chlorophyll b, from 23% to 3% for carotenoids and stimulation of 1% and 2% was observed 28 and 35 DAA, respectively. Plants infested (untreated) by field dodder had lower values of most anatomical parameters, compared to noninfested plants. The measured anatomical parameters of sugar beet leaves and petiole had significantly higher values in noninfested plants and plants treated with propyzamide than in untreated plants. Also, the results showed that propyzamide is an adequate herbicide for control of field dodder at the stage of early infestation.     

Hormetic effect of glyphosate on Urochloa decumbens plants

Abstract

Urochloa decumbens plants may be reached by herbicide drift from applications of glyphosate from neighboring areas or by variations during applications. Considering the different phenological stages and size of plants in these areas, the amount of active ingredient that reaches the plants probably varies. The objective of this study was to evaluate the effects of the application of different doses of glyphosate on U. decumbens plants. Two greenhouse experiments were conducted with two replications at different times. The first experiment evaluated the biological response of U. decumbens plants to glyphosate doses (0, 2.81, 5.63, 11.25, 22.5, 45, 90, 180, 360, 720, and 1,440?g a.e. ha^?1), with six replications. The second experiment evaluated the response of U. decumbens plants to the application of a selected low dose of 11.25?g a.e. ha^?1. Evaluations of injury were performed at 0, 7, 14, and 21?days after application, and dry weight of plants was determined for each evaluation period. U. decumbens plants increased in dry weight when using the glyphosate dose of 11.25?g a.e. ha^?1. However, plants had different responses to the application of this low dose. It can promote both stimulation and inhibition of plant growth.     

Uptake,translocation, and control of trumpet flower (Tecoma stans) with aminocyclopyrachlor

To gain a better understanding of the physiology of the herbicide aminocyclopyrachlor in young plants of trumpet flower, the uptake and translocation were evaluated after the application of herbicide. This was determined by treating individual leaves with formulated herbicides plus ¹⁴C-aminocyclopyrachlor after the application of the formulated herbicide. This experiment used a randomized experimental design with three replications. In addition, field studies were conducted to assess the effectiveness of foliar applications of aminocyclopyrachlor in association with metsulfuton-methyl. The plant absorbed 20% of the herbicide applied. The translocation percentage did not surpass 5% of the total amount applied. Only 1% of the herbicide applied was translocated to the roots. Rate of 40 + 13 g a.i. 100 L^?1 of aminocyclopyrachlor+metsulfuron-methyl was effective to control T. stans.