温度对污泥热解产物及特性的影响

温度是污泥热解产物及产物分布状况的主要影响因素之一。为了确定最优的热解温度,为不同的热解工艺提供参考,用直径为200mm的外热式固定床反应器,以唐山西郊污水处理厂剩余污泥为实验物料,在终温为250～700℃并在初期通以氮气的情况下,对污泥的热解产物分布及特性进行了研究。实验表明:在物料成分和其它条件不变的情况下,热解反应所需时间随着热解终温的升高而缩短;热解气和热解焦油的质量分数增大;焦炭质量分数减小。热解焦炭的工业分析表明,随热解终温的升高挥发分减少、固定碳和灰分增加。热解焦油的热值在10～43MJ·kg-1之间;焦炭的热值10～24MJ·kg-1之间。     

The effect of 4-Nonylphenol on the pigmentation of<Emphasis Type="Italic">Ocimum basilicum</Emphasis> (Basil)

BACKGROUND, AIM AND SCOPE: Tests during the last few years have confirmed that 4-nonylphenol (4-NP) can have oestrogen-like effects (xeno-hormone) on animal organisms. The objective was to firstly evaluate the ecotoxicological effects of 4-NP on plants such as hydrocultures. To clarify how this substance interferes with the photosynthetic system of plants, various tests were carried out using the basil plant (Ocimum basilicum). METHODS: The effect of the pollutant 4-NP on the pigment content in the leaves of the basil plant was analysed with the use of High-Performance-Liquid-Chromatography (HPLC). RESULTS AND DISCUSSION: A general assessment of the HPLC data revealed that plants that came in contact with the 4-nonylphenol showed a change in pigmentation. More chlorophyll a and b was produced, although at the same time a higher production of degradation products and by-products of the chlorophylls was observed. These occurrences can therefore be seen as an impairment of the photosynthetic process. The contaminated plants produced less xanthophylls than the non-contaminated ones, though these differences were statistically not significant. CONCLUSION AND PERSPECTIVE: The variations on the pigment content in the leaves of the basil plant can be interpreted as a consequence of the 4-NP application. It was, however, not investigated whether the plants absorbed the pollutants directly. The effect could have been caused by adsorption of the oily substance to the roots, and this could have led to a hindrance of the uptake of nutrients and possibly water. In order to clarify this further, biochemical experiments are being conducted.     

酵母菌处理黄泔水试验研究

采用小型和中型试验装置利用酵母菌对豆制品生产中产生的黄泔水进行预处理 ,对其实用性和经济性进行了探讨。试验分析了一些对处理过程和效果有关的主要影响因素 ,并通过中试为生产型设备的设计提供基本参数。     

UV/NO3-光化学降解水中的磺胺甲恶唑

本文研究了UV/NO₃^-体系对水中磺胺甲恶唑（SMX）的降解;考察了NO₃^-用量、pH值、SMX初始浓度、水体成分中常见的无机阴离子（Cl^-、SO₄^2-和HCO₃^-）和天然有机物（NOM）对SMX去除的影响;最后探讨了SMX在该体系中的降解产物和转化机理.结果表明：相比于单独UV,UV/NO₃^-对SMX的去除效果更优,这可能归因于UV激发NO₃^-产生的羟基自由基（HO^·）,通过加入HO^·淬灭剂甲醇,有力地证明了体系中HO^·的存在及其对SMX的降解作用.SMX在UV/NO₃^-体系中的降解符合准一级反应动力学.SMX的去除效率随着NO₃^-浓度的增加而逐渐提高,随着其初始浓度的增大而减小.溶液pH值对UV/NO₃^-降解SMX的影响显著,SMX去除效率表现为酸性>中性>碱性.向UV/NO₃^-体系中加入不同浓度的Cl^-和SO₄^2-对SMX的降解基本没有影响;HCO₃^-对SMX的去除有显著的促进作用,这可能归因于HO^·同HCO₃^-反应产生的碳酸根自由基（CO₃^·-）;NOM的存在会抑制SMX的降解,且NOM浓度越高,抑制越明显.在UV/NO₃^-降解SMX的反应中,根据检出的5种产物,提出SMX可能的转化机理包括4种不同的反应路径,分别为断键反应、脱氨羟基化、羟基化和亚硝化.     

高铁酸盐(Fe(Ⅵ))氧化去除水中PPCPs的研究进展

药物和个人护理用品(PPCPs)采用传统的污水处理方法不易去除,高铁酸盐(Fe(VI))因具有强氧化性,且氧化产物Fe(III)具有絮凝作用,近年来被广泛应用于去除PPCPs。介绍了Fe(VI)近年来的制备进展,分析了Fe(VI)去除PPCPs的效率及影响因素,探讨了Fe(VI)与PPCPs的反应机理及产物、中间产物的毒性变化,并展望了未来Fe(VI)去除PPCPs的研究方向。Fe(VI)能有效去除多种PPCPs,去除效率受p H值、温度、Fe(VI)初始浓度和PPCPs性质影响,Fe(VI)与PPCPs反应的中间产物毒性值得关注。     

Guided group discussion and the reported use of toxic products: The persuasiveness of hearing others’ views

Guided group discussion ( [Lewin et?al., 1952] , [Werner, 2003] and [Werner and Adams, 2001] ) was used to persuade groups to replace their toxic home and garden chemicals with nontoxic alternatives. We hypothesized that discussion would allow participants to hear others endorse the new information, and this normative information would facilitate persuasion. Approximately two months after the group discussion, we obtained questionnaires from the organizer of the meeting and a member of the group who had missed the meeting because of another obligation (i.e., not because of disinterest in the topic). Most organizers were female and analyses were limited to females. This quasi-experimental matched control group design indicated that those who attended the meeting were more favorable towards using nontoxics and more interested in sharing leftover toxic products with friends (instead of discarding them). Path and mediation analyses showed that the organizer’s evaluation of the meeting predicted her final attitude, and perceptions that the group endorsed the material (perceived group norm) partially mediated this relationship. A second mediation analysis showed that evaluation of the meeting predicted intention to share leftover toxics and this relationship was fully mediated by the organizer’s impression that the group would also share leftovers. The results support the idea that persuasion is based both on individual evaluation and normative influence, especially when people are not confident others will accept the behavior, such as sharing leftover toxic products.     

Decision rules for recycling returned products

Most retail and on-line outlets allow customers to easily return defective or even non-defective products. Due to increasing environmental and sustainable concerns, disposal of returned products is often costly and undesirable. Furthermore, these products contain parts and materials of value that can contribute to the companies' profit. One way to take advantage of these returns is by utilising good returned parts in production of after-market products. Recycling of parts from products at the end of their useful lives has been studied for a long time. Many of these studies, however, are focused on repairs and refurbishing of such products for reuse.

This paper addresses recycling of rather new parts recovered from returned products. In this process parts are assembled with other parts recovered from other products to make a complete unit. The main objective of this study is to provide quantitative decision rules for justification of recycling of returned parts. The proposed method consists of a computer-based simulation decision model that, given a set of production system parameters, determines the breakeven point for the primary production rate at which recycling is justified. The application of the system to several scenarios is demonstrated through a numerical example.     

Cyhalofop‐p‐butyl mobility and distribution of residues in soil at various depths

This study was conducted to evaluate cyhalofop‐p‐butyl mobility in a sandy loam soil and subsequent distribution of residues at various depths under field conditions. Soil samples were taken from 0 to 150 cm depths at 3–90 d after rains in lysemeter of 1 and 2 m depths. Cyhalofop‐p‐butyl application at two rates and subsequent precipitation had a significant impact on soil, physico‐chemical properties and herbicide mobility. Precipitation caused substantial mobility of cyhalofop‐p‐butyl in the soil and 1.1–7.6 μg L^?1 of cyhalofop‐p‐butyl was found in leachates. Cyhalofop‐p‐butyl residues in the leachates were probably due to preferential flow through the soil. Cyhalofop‐p‐butyl residues were detected in significant amounts from the soil up to 10 d, later, residues were found below the detection limit but its three transformation products viz., cyhalofop acid, diacid, and phenol were detected.     

Carbon accounting of material substitution with biomass: Case studies for Austria investigated with IPCC default and alternative approaches

There is evidence that the replacement of carbon-intensive products with bio-based substitutes (‘material substitution with biomass’) can be highly efficient in reducing greenhouse gas (GHG) emissions. Based on two case studies (CS1/2) for Austria, potential benefits of material substitution in comparison to fuel substitution are analysed. GHG savings are calculated according to default IPCC approaches (Tier 2 method assuming first-order decay) and with more realistic approaches based on distribution functions. In CS1, high savings are achieved by using wood residues for the production of insulating boards instead of energy. The superiority of material substitution is due to the establishment of a long-term carbon storage, the high emission factor of wood in comparison to natural gas and higher efficiencies of gas-fired facilities.The biomass feedstock in CS2 is lignocellulosic ethanol being used for bio-ethylene production (material substitution) or replacing gasoline (fuel substitution). GHG savings are mainly due to lower production emissions of bio-ethylene in comparison to conventional ethylene and significantly lower than in CS1 (per unit of biomass consumed). While CS1 is highly robust to parameter variation, the long-term projections in CS2 are quite speculative.To create adequate incentives for including material substitution in national climate strategies, shortcomings of current default accounting methods must be addressed. Under current methods the GHG savings in both case studies would not (fully) materialize in the national GHG inventory. The main reason is that accounting of wood products is confined to the proportion derived from domestic harvest, whereas imported biomass used for energy is treated as carbon-neutral. Further inadequacies of IPCC default accounting methods include the assumption of exponential decay and the disregard of advanced bio-based products.     

Effect of soluble maillard reaction products on cadA expression in Salmonella typhimurium

The presence of Maillard reaction products (MRP) in foods and food components is due to the non-enzymatic reaction between protein and carbohydrate residues triggered by thermal steps during food processing. The objective of this study was to assess the effect of MRPs and increasing lysine concentrations on S. Typhimurium growth and the expression of cadA which may be an indirect determinant of Salmonella virulence response. Variations in lysine concentrations (from 0 to 0.5 mM) did not exert any effect either on the final optical density after 6-hour incubation or the growth rates of S. Typhimurium in media containing MRPs. In contrast to the reduced final absorbancy of the bacterial cultures grown with histidine and arginine MRPs supplementations (0.1%), growth rates, in general, remained unaltered by all MRPs at each lysine concentration when compared to the control (M9 pH 5.8, no MRPs added). The induction levels of cadA in media containing 0.1% MRPs were close to cadA induction in the reference media (M9, pH 5.8 and no MRPs) and did not exceed the corresponding values by more than approximately 30%. Although the observed negligible induction of cadA under these conditions complies with the concept of its potential “anti-virulence” function, additional studies involving various concentrations and more refined MRPs are needed.