Is Ammophila arenaria (Marram grass) a threat to South African dune fields?

Ammophila arenaria (marram grass) was introduced to South Africa from Europe as a means of stabilizing the Cape Flats in the 1870s, but was only successfully established in the 1890s as it was found that seeds from the first introductions did not readily germinate. By the end of the last century, it was successfully used as a dune stabilizing grass. It is now widely used in stabilization projects along the Cape coastline, being established by planting cuttings or whole plants. Because of problems experienced of marram becoming invasive, especially on the west coast of North America, and the fact that we have many invasive species which threaten our indigenous dune fields, studies have been initiated on this plant in South Africa. Most work to date has involved investigating the methods used to establish the plant in stabilization sites, and very little has been done on the biology of the species in this country. Marram is generally thought not to seed in South Africa, and thus its spread has been limited. However, in the light of recent reports of successful germination of the seed, detailed studies on the phenology of seed production and establishment in natural areas will be undertaken. Studies on the natural control by fungal species and nematodes will be carried out in conjunction with work done in the Netherlands, so that a comparison of the biology of the species in South Africa can be made with that in Europe, where it is used extensively to stabilize dunes.     

IsAmmophila arenaria (Marram grass) a threat to South African dune fields?

Ammophila arenaria (marram grass) was introduced to South Africa from Europe as a means of stabilizing the Cape Flats in the 1870s, but was only successfully established in the 1890s as it was found that seeds from the first introductions did not readily germinate. By the end of the last century, it was successfully used as a dune stabilizing grass. It is now widely used in stabilization projects along the Cape coastline, being established by planting cuttings or whole plants. Because of problems experienced of marram becoming invasive, especially on the west coast of North America, and the fact that we have many invasive species which threaten our indigenous dune fields, studies have been initiated on this plant in South Africa. Most work to date has involved investigating the methods used to establish the plant in stabilization sites, and very little has been done on the biology of the species in this country. Marram is generally thought not to seed in South Africa, and thus its spread has been limited. However, in the light of recent reports of successful germination of the seed, detailed studies on the phenology of seed production and establishment in natural areas will be undertaken. Studies on the natural control by fungal species and nematodes will be carried out in conjunction with work done in the Netherlands, so that a comparison of the biology of the species in South Africa can be made with that in Europe, where it is used extensively to stabilize dunes. Nomenclature: Arnold & de Wet (1993) for vascular plants.     

污水稳定塘污泥降解规律的研究

选择具有代表性的污水稳定塘,测量和分析了其污泥的淤积情况和降解规律。研究结果表明:污泥在稳定塘中的纵深分布随污泥深度的增加,总固体逐渐增加,而挥发性固体逐渐减少;稳定塘中的污泥降解符合由室内静态模拟得出的污泥降解规律的数学模型。      

Combined amendment reduces soil Cd availability and rice Cd accumulation in three consecutive rice planting seasons

The scientific application of stabilized materials has been considered an effective method for the in situ remediation of Cd-contaminated soil. This study aimed to investigate the persistence of the effect of a combined amendment of limestone and sepiolite(LS) on soil Cd availability and accumulation in rice grown in a mildly Cd-contaminated paddy field(0.45 mg/kg of Cd) over three consecutive rice seasons. 1125–4500 kg/ha of LS was applied to the soil before the first rice planting season and 5...     

废水稳定塘串联组合系统在冲击负荷下的试验与数学模拟

本文通过室内试验揭示了稳定塘串联系统较之单塘系统具有较高的抗冲击负荷能力。建立了描述稳定塘串联系统动态特性的数学模型,并应用计算机对有机物浓度冲击负荷和流量冲击负荷下的串联组合系统进行模拟,验证并发展了室内试验的结论:稳定塘的串联组合系统对有机物浓度冲击负荷和进水流量冲击负荷均具有缓冲能力。      

The Journal of Coastal Conservation, 1995–2004

This paper concludes the publication of theJournal of Coastal Conservation from 1995–2004 after the European Coastal Union and the Publishers decided to terminate the production of the journal. We look back at the 206 research papers published in this period while concentrating on Geographical and ecological variation, Focuses and trends, and Progress in European coastal conservation and management. Three indices are added: (1) a list of the 206 papers; (2) an Author Index; and (3) a Subject Index based on the titles, keywords and some additional important subjects found in the tables and figures.     

不溶性淀粉黄原酸盐聚丙烯酰胺接枝共聚物除铜降浊研究

分别以含Cu2 模拟废水和电镀废水为对象,研究了不溶性淀粉黄原酸盐聚丙烯酰胺接枝共聚物(ISXA)去除Cu2 和降低浊度的能力.论述了该药剂去除Cu2 和降低浊度的优点和机理,探讨了去除Cu 2 的影响因素,如投药量、pH和反应时间.试验表明:(1)对于电镀废水,在5.5倍理论投药量、pH为5.0、反应10 min的条件下,Cu2 去除率为98.89%;当pH≥7时,含Cu2 残渣稳定;在2 mol/L的盐酸和硝酸溶液中浸泡6 h含Cu2 残渣,Cu2 回收率为93.08%;(2)对于含Cu2 模拟废水,在4.5倍理论投药量、pH为5.0、反应10 min的条件下,Cu2 去除率可达99.14%,除Cu2 和降浊存在协同作用.     

Continuous CO2 capture and MSWI fly ash stabilization, utilizing novel dynamic equipment

Novel dynamic equipment with gas in and out continuously was developed to study the capture capacity of CO₂. Municipal solid waste incineration (MSWI) fly ash has a high capture rate of CO₂ in CO₂-rich gas. Fly ash can sequester pure CO₂ rapidly, and its capacity is 16.3 g CO₂/100 g fly ash with no water added and 21.4 g CO₂/100 g fly ash with 20% water added. For simulated incineration gas containing 12% CO₂, the capture rate decreased and the capacity was 13.2 g CO₂/100 g fly ash with no water added and 18.5 g CO₂/100 g fly ash with 20% water added. After accelerated carbonation, the C and O contents increased, indicating CO₂ capture in the fly ash; CO₂ combines with Ca(OH)₂ to form CaCO₃, which increased the CaCO₃ content from 12.5 to 54.3%. The leaching of Pb markedly decreased from 24.48 to 0.111 mg/L.     

Transport of citrate and polymer coated gold nanoparticles (AuNPs) in porous media: Effect of surface property and Darcy velocity

With the release of nanoparticles(NPs) into the subsurface,it is imperative to better understand the fate and transport of NPs in porous media.Three types of stable AuNPs were used as model NPs to investigate the impact of surface coatings(type and coverage) and water velocity on the NP transport in a porous media(column studies).The NPs were electrostatic stabilized citrate AuNPs and sterically stabilized AuNPs with amphiphilic block co-polymer(PVA-COOH) in two particle/polymer ratios(weak vs.strong stabilization).The citrate AuNPs transport was sensitive to ionic changes in the mixing front of the plume,where destabilization occurred,and will therefore depend on the size/type of release.Blocking of deposition sites by aggregates was seen to facilitate transport,whereby a higher flow velocity(larger shadow zone) also resulted in better transport.The polymeric surface coating had great impact with steric repulsion as a main force contributing to the transport of NPs in the porous media.Sufficient polymer coating was crucial to obtain highly unfavorable attachment conditions(very low α) where the enhanced NP mobility was independent of the water velocity(comparable to solute tracer).Without sufficient steric stabilization,the transport and recovery was significantly reduced compared to the solute tracer,but increased with increasing water velocity.This highlights the importance of sufficient surface coating to achieve enhanced mobility,but also the increased risk of spreading to down-gradient receptors.For the(weakly) sterically stabilized NPs,the loss of polymer through ligand exchange with the porous media negates transport.     

Early development of vegetation in restored dune plant microhabitats on a nourished beach at Ocean City, New Jersey

Topography and vegetation of restored dunes on a developed barrier island were examined after a large-scale beach nourishment project. Restoration began in 1993 using sand-trapping fences andAmmophila breviligulata Fern. plantings. Subsequent growth of dunes was favored by installing new fences and suspending beach raking to accommodate nesting birds. Plant species richness, percent cover of vegetation, and height ofA. breviligulata were sampled in 1999 on seven shore perpendicular transects in six dune microhabitats (backdune, primary crest, mid-foredune, swale, seaward-most fenced ridge, incipient dune on the backbeach). A total of 26 plant taxa were found at all seven sites. Richness and percent cover were greatest in the backdune and crest, especially in locations that predated the 1992 nourishment. Richness was greater where fences enhanced stabilization. Fences initially compensate for time and space and allow vegetation to develop rapidly, but maintenance nourishment is required to protect against wave erosion and ensure long-term viability of habitat. An expanded environmental gradient is an option, where beach nourishment provides space for a species-rich crest and backdune to develop, while the incipient dune remains dynamic. Options where space is restricted include a dynamic, full-sized seaward section of a naturally functioning dune (truncated gradient) or a spatially restricted sampler of a wider natural dune (compressed gradient) maintained using fences. Expanded and truncated gradients may become self-sustaining and provide examples of natural cycles of change. Compressed gradients provide greater species richness and flood protection for the available space, but habitats are vulnerable to erosion, and resident views may be impaired.