Nutrients Can Enhance Phytoremediation of Copper-Polluted Soil by Indian Mustard

An orthogonally designed experiment was conducted to study the single and combined effects of N, P and K on phytoremediation of Cu-polluted soil by Indian mustard. Addition of fertilizer N and P significantly increased Indian mustard shoot yield. Two high treatments combined with N resulted in the highest yields, followed by low-P combined with N. In contrast, high P with no N gave no yield increase and K had no effect on yield of Indian mustard. Nitrogen and P increased the amount of chlorophyll in the leaves, indicating that the yield increases were due to enhanced photosynthesis. Nitrogen application had no effect on plant Cu concentrations but addition of P slightly decreased plant Cu concentrations, likely a dilution effect resulting from the increase in yield. Among the treatments, N and P applied at 100 and 200 mg kg^–1 respectively with no K application resulted in the highest Cu uptake. Thus, a combination of low N and high P produced a yield increase in Indian mustard that was more than adequate to compensate for a slight decrease in Cu concentration, resulting in the highest Cu removal from the contaminated soil.     

有机磷农药的残留、毒性及前景展望

有机磷农药自问世到现在已有70年的历史。因为它的高效、快速、广谱等特点，一直在农药中占有很重要的位置，对世界农业的发展起了很重要的作用。但随着它的不断使用，也暴露出了很多问题，如高残留、毒性强等，尤其在环保意识日益增强的今天，其暴露的问题引起了人们的高度重视。文章主要对有机磷农药的残留、毒性作了初步的分析，指出尽快开发替代产品是今后使用有机磷农药的方向。     

Application of adaptive cluster sampling to low-density populations of freshwater mussels

Freshwater mussels appear to be promising candidates for adaptive cluster sampling because they are benthic macroinvertebrates that cluster spatially and are frequently found at low densities. We applied adaptive cluster sampling to estimate density of freshwater mussels at 24 sites along the Cacapon River, WV, where a preliminary timed search indicated that mussels were present at low density. Adaptive cluster sampling increased yield of individual mussels and detection of uncommon species; however, it did not improve precision of density estimates. Because finding uncommon species, collecting individuals of those species, and estimating their densities are important conservation activities, additional research is warranted on application of adaptive cluster sampling to freshwater mussels. However, at this time we do not recommend routine application of adaptive cluster sampling to freshwater mussel populations. The ultimate, and currently unanswered, question is how to tell when adaptive cluster sampling should be used, i.e., when is a population sufficiently rare and clustered for adaptive cluster sampling to be efficient and practical? A cost-effective procedure needs to be developed to identify biological populations for which adaptive cluster sampling is appropriate.     

Treatment of azo dye Orange II in a sequential anaerobic and aerobic-sequencing batch ractor system

We studied the biodegradation of Orange II in a sequential anaerobic and aerobic-sequencing batch reactor system. Granular activated carbon was used either packed into a column or added directly into the anaerobic reactor to investigate the treatment performance between the two operation conditions. We found that the circulation of mixed liquor between the anaerobic reactor and the carbon-packed column enhanced the chemical oxygen demand from 28 to 52% and Orange II removal efficiencies from 88 to 96%, under simultaneous adsorption and biodegradation process. The morphology of microbes was observed under an electron-scanning microscope.     

土壤-植物根际磷的生物有效性研究进展

探讨土壤-植物根际磷素养分状况及利用机理,提高土壤磷的生物有效性,使土壤中潜在的难溶性磷库活化,提高磷肥利用率,对促进农业生产的持续高效发展和陆地生态系统的良性循环具有重大的现实意义。文章从这一角度出发,论述了根际土壤中根际微生物、根际pH值、根系分泌物、菌根、根际土壤磷酸酶等各种因素对提高土壤磷素利用率的机理。     

活性污泥运转效能的生物监测

讨论了θ/℃，pH,ρ(BOD)/mgL^-1,ρ(COD)/mgL^-1,ρ(SS)/mgL^-1,ρ(N)/mgL^-1,ρ(P)/mgL^-1,w(Cu^2 )/10^-6等几个影响活性污泥状况的理化因素，认为必须调节均化进水的水质水量，并调控污泥龄，回流比，曝气量等各种运行参数，分析了活性污泥的生理，生化监测法及运用细菌，藻类，原生动物，后生动物所进行的生物监测，提出通过监测原生动物群落动态是判断活性污泥运行效能的一种较简便准确的方法，比较了斑点杂交法（dot blot hybrid-ization)，最大机率法（most probable number methods,MPNM),抗体（antibody)法和荧光原位杂交（fluorescent in situ hy-bridization,FISH)法检测氨氧化菌（ammonia-oxidizing bacteria)数量的效果，表明斑点杂交法具有高的准确度，并能检测出较低密度的细菌，MPNM低估了细菌数量，抗体法有高估细菌数的可能，FISH法对氨氮含量高的活性污泥混合液检测结果较好，但对低氨氮含量污水厂出水和河水的检测效果不佳。     

复合优势菌技术处理M废水

以某厂橡胶促进剂M废水为研究对象，通过常规生物处理工艺与复合优势菌生物处理工艺对该废水处理效果的比较，认为复合优势菌生物处理工艺是目前处理M废水的最佳工艺。     

The influence of sorption material preparation on the removal of metal ions from the aqueous solution

ABSTRACT

Very important in adsorption processes is the preparation of material sorbents and from this reason, the impact of washing agent of raw sorbent was analysed. The adsorption capacity was studied in relation to the function of the equilibrium time, the amount of biosorbent and the initial metal(II) ions concentration. In this research for the sake of comparison, the sorptive properties of out-of-date coffee were compared to coffee washed with different agents (mineral acids and water). The scanning electron microscopy and Fourier transform infrared spectroscopy were used to characterise the biosorbents and to identify the functional groups that participated in metal(II) ions bonding. The obtained results clearly indicate that the out-of-date coffee are effective biosorbent for cadmium(II) and nickel(II) ions from aqueous solution. However, for metal(II) ions removal efficiency could influence sorbent preparation and nickel(II) ions were best adsorbed on coffee washed with water, but cadmium(II) ions on raw biosorbent (out-of-date coffee). The best results of sorption were achieved after the contact time of 30 and 60?min, respectively for cadmium(II) and nickel(II) ions.     

Fecundity as a Basis for Risk Assessment of Nonindigenous Freshwater Molluscs

Abstract:  The most efficient way to reduce future damages from nonindigenous species is to prevent the introduction of harmful species. Although ecologists have long sought to predict the identity of such species, recent methodological advances promise success where previous attempts failed. We applied recently developed risk assessment approaches to nonindigenous freshwater molluscs at two geographic scales: the Laurentian Great Lakes basin and the 48 contiguous states of the United States. We used data on natural history and biogeography to discriminate between established freshwater molluscs that are benign and those that constitute nuisances (i.e., cause environmental and/or economic damage). Two statistical techniques, logistic regression and categorical tree analysis, showed that nuisance status was positively associated with fecundity. Other aspects of natural history and biogeography did not significantly affect likelihood of becoming a nuisance. We then used the derived statistical models to predict the chance that 15 mollusc species not yet in natural ecosystems would cause damage if they become established. We also tested whether time since establishment is related to the likelihood that nonindigenous mollusc species in the Great Lakes and United States would cause negative impacts. No significant relationship was evident at the U.S. scale, but recently established molluscs within the Great Lakes were more likely to cause negative impacts. This may reflect changing environmental conditions, changing patterns of trade, or may be an indication of "invasional meltdown." Our quantitative analyses could be extended to other taxa and ecosystems and offer a number of improvements over the qualitative risk assessments currently used by U.S. (and other) government agencies.