苯乙烯蒸馏残焦油中粗品苯乙烯的回收工艺

利用苯乙烯能与某些特定溶剂及水形成三元共沸物的特点,开发出从苯乙烯蒸馏塔釜排放的残焦油中提取粗品苯乙烯的新工艺。苯乙烯回收率可达92%以上,粗品苯乙烯的含量在98%（质量分数）以上。     

废旧电路板上残留焊锡剥离液的研制

以硝酸-磺酸型退锡剂为基础配方,研制了一种脱除废旧电路板表面残留焊锡的剥离液.该剥离液以硝酸为氧化剂,氨基磺酸为稳定剂,苯并三氮唑为铜的缓蚀剂.实验结果表明:剥离液的最佳配比为硝酸浓度3 mol/L,氨基磺酸浓度0.4 mol/L,苯并三氮唑浓度0.08 mol/L;每升剥离液可处理3.5 kg废旧电路板,处理后电路板中的铅离子含量降至100 mg/kg以下.该剥离液处理后的电路板表面的铜箔保持完好,基本没有被剥离液浸蚀.     

Recovery of high purity zinc from filter ash produced during the thermal treatment of waste and inerting of residual materials.

The method described below recovers zinc, a valuable metal that is present in high concentrations in filter ash from the thermal treatment of waste, and returns the filter ash stripped of heavy metals to the combustion process in order to destroy organic substances. On an industrial scale, the heavy metals in the filter ash were mobilized by means of hydrochloric acid in the acidic fluids produced in the flue-gas scrubbing process without the addition of further chemicals. A pilot plant for implementing the selective reactive extraction (SRE) method on the ash extracts, using a highly selective complexant, was operated over a period of several months in order to obtain a concentrated, high-purity zinc salt solution (mono metal solution). A zinc depletion rate of 99.8% in the aqueous extract was achieved using mixer-settler units. The residual zinc concentration in the waste water was then < 2 mg L(-1). By stripping the loaded organic phase, a concentrated, high-purity mono metal solution with 190 g L(-1) zinc was obtained. Zinc metal with a purity > 99.99% is then separated by means of electrolysis. To destroy organic substances present in the filter ash, particularly dioxins and furans, the extracted filter ash cake was returned to the combustion process together with household waste. Plant operation, raw and pure gas parameters, and quality of the bottom ash produced were not impacted by such recirculation. The profitability of the overall process is attributable both to the recovery of valuable zinc metal and to the cost savings made in waste water treatment and in the disposal of the waste combustion residues because the remaining mixture of filter ash and bottom ash can be reused in a combined form. This method therefore supports the sustainable and economically viable reuse of filter ash.     

环己烷氧化废碱液的回收利用

介绍了一种从环己烷氧化废碱液中回收高价值有机酸的新方法。用氢氧化钠碱熔处理废碱液中的羟基己酸及其聚合物，可使废碱液中己二酸的质量分数由3．18％提高到8．74％，且环境效益和经济效益显著。     

Vitrification as an alternative to landfilling of tannery sewage sludge

Due to high content of heavy metals such as chromium, tannery sewage sludge is a material which is difficult to be biologically treated as it is in the case of organic waste. Consequently, a common practice in managing tannery sewage sludge is landfilling. This poses a potential threat to both soil and water environments and it additionally generates costs of construction of landfills that meet specific environment protection requirements. Vitrification of this kind of sewage sludge with the addition of mineral wastes can represent an alternative to landfilling.The aim of this study was to investigate the possibility of obtaining an environmentally safe product by means of vitrification of tannery sewage sludge from a flotation wastewater treatment process and chemical precipitation in order to address the upcoming issue of dealing with sewage sludge from the tannery industry which will be prohibited to be landfilled in Poland after 2016. The focus was set on determining mixtures of tannery sewage sludge with additives which would result in the lowest possible heavy metal leaching levels and highest hardness rating of the products obtained from their vitrification.The plasma vitrification process was carried out for mixtures with various amounts of additives depending on the type of sewage sludge used. Only the materials of waste character were used as additives.One finding of the study was an optimum content of mineral additives in vitrified mixture of 30% v/v waste molding sands with 20% v/v carbonate flotation waste from the zinc and lead industry for the formulations with flotation sewage sludge, and 45% v/v and 5% v/v, respectively, for precipitation sewage sludge. These combinations allowed for obtaining products with negligible heavy metal leaching levels and hardness similar to commercial glass, which suggests they could be potentially used as construction aggregate substitutes. Incineration of sewage sludge before the vitrification process lead to increased hardness of the vitrificates and reduced leaching of some heavy metals.     

乙醇溶析结晶法从白炭黑废母液中回收硫酸钠

以乙醇为溶析剂，通过过滤—中和—蒸馏浓缩—溶析结晶等工序，从白炭黑废母液中回收硫酸钠。考察了硫酸钠回收效果的影响因素，并进行了热能消耗和处理成本的分析。实验结果表明：乙醇的加入量对硫酸钠溶解度和蒸馏浓缩过程有着显著影响；在蒸馏醇水比（乙醇与中性废母液的体积比）为0.27，浓缩废母液中硫酸钠质量浓度为69.27 g/L，溶析醇水比（乙醇与浓缩废母液的体积比）为1的最佳工艺条件下，白炭黑废母液中硫酸钠的一次回收率可达69.94%，硫酸钠产品的纯度达到97.3%。     

Study of the solubility and stability of polystyrene wastes in a dissolution recycling process

Dissolution with suitable solvents is one of the cheapest and more efficient processes for polystyrene waste management. In this work the solubility of polystyrene foams in several solvents benzene, toluene, xylene, tetrahydrofuran, chloroform, 1,3-butanediol, 2-butanol, linalool, geraniol, d-limonene, p-cymene, terpinene, phellandrene, terpineol, menthol, eucalyptol, cinnamaldheyde, nitrobenzene, N,N-dimethylformamide and water has been determined.Experimental results have shown that to develop a “green process” the constituents of essential oils, d-limonene, p-cymene, terpinene, phellandrene, are the most appropriate solvents. The action of these solvent does not produce any degradation of polymer chains. The solubility of the polymer in the mentioned solvents at different temperatures has been investigated. The solvent can be easily recycled by distillation.     

氟化工“三废”的资源化利用

结合我国氟化工行业发展现状,分析了含氟"三废"产生情况及处置方法的最新研究进展,并通过实际工程案例进行论述。氟化工生产过程污染物主要有含氟废气及副产氯化氢、含氟高沸物及含氟污泥等。通过将氯化氢用于工业清洗及制备氯化钙、氯化铝等化学品能够合理消耗副产盐酸。焚烧处理含氟有机废气产生的氟化氢气体经水洗后副产氢氟酸。含氟高沸物通过精馏分离出高沸物组分生产高附加值产品。含氟污泥可制成建筑材料,最优工业化利用途径仍在积极研究中。     

Production and degradation of polyhydroxyalkanoates in waste environment

Polyhydroxyalkanoates (PHAs) are energy/carbon storage materials accumulated under unfavorable growth condition in the presence of excess carbon source. PHAs are attracting much attention as substitute for non-degradable petrochemically derived plastics because of their similar material properties to conventional plastics and complete biodegradability under natural environment upon disposal. In this paper, PHA production and degradation in waste environment as well as its role in biological phosphorus removal are reviewed. In biological phosphorus removal process, bacteria accumulating polyphosphate (poly P) uptake carbon substrates and accumulate these as PHA by utilizing energy from breaking down poly P under anaerobic condition. In the following aerobic condition, accumulated PHA is utilized for energy generation and for the regeneration of poly P. PHA production from waste has been investigated in order to utilize abundant organic compounds in waste water. Since PHA content and PHA productivity that can be obtained are rather low, PHA production from waste product should be considered as a coupled process for reducing the amount of organic waste. PHAs can be rapidly degraded to completion in municipal anaerobic sludge by various microorganisms. ©     

Thermal process of fluff: Preliminary tests on a full-scale treatment plant

Until only recently fluff has been largely disposed of in controlled landfill sites. However, in Europe environmental regulations, including the EU Landfill Directive 1999/31/EC and ELV (End of Life Vehicle) Directive 2000/53/EC, have dramatically increased the pressure on all stakeholders to develop alternative solutions. As increasingly stringent legislation forces Shredder Residues (SR) to be diverted from landfilling, newly developed technologies will be in a position to compete for the market value of disposing of the waste.However, the fluff waste stream is so variable that it cannot be automatically assumed that processes developed for one type of fluff will prove to be suitable for other fluff streams. This situation has contributed towards convincing stakeholders to withhold investment funds or delay taking decisions as to how best to proceed; as a consequence, very few technologies have been fully developed on a commercial basis. It is of particular interest therefore that commercial alternatives to be used in dealing with this complex waste stream should be identified.The present paper illustrates the findings of a full-scale thermal treatment performed on SR samples obtained from various shredding plants. The outcome of the study provides an important contribution towards assessing the feasibility and reliability of the process, thus constituting a basic prerequisite for process performance evaluation. The full-scale plant, designed for the thermo-valorization of tyres, was purpose-modified to allow for fluff combustion. Three different fluff compositions (car fluff with different percentage of shredding, whites and 100% car fluff) were taken into consideration. Both the raw samples and solid products were thoroughly characterized. Combustion emissions were continuously analyzed during the test period, alternatively operating for tyre and fluff combustion. Classification of combustion residues for landfill disposal was carried out indicating only 2% (ashes) as hazardous waste. Preliminary results, obtained from a unsophisticated thermodynamic analysis of the process, indicated a value of 0.61 for energy efficiency parameter calculated in accordance with the Directive 2008/98/EC.To conclude, the thermal treatment investigated may be deemed an appropriate technique for use in managing fluff. Indeed, values obtained for all organic and inorganic contaminants released into the atmosphere were lower than legal limits prescribed, and a significant energy content was recovered from waste fractions.     

Hidden values in bauxite residue (red mud): Recovery of metals

Bauxite residue (red mud) is a hazardous waste generated from alumina refining industries. Unless managed properly, red mud poses significant risks to the local environment due to its extreme alkalinity and its potential impacts on surface and ground water quality. The ever-increasing generation of red mud poses significant challenges to the aluminium industries from management perspectives given the low proportion that are currently being utilized beneficially. Red mud, in most cases, contains elevated concentrations of iron in addition to aluminium, titanium, sodium and valuable rare earth elements. Given the scarcity of iron supply globally, the iron content of red mud has attracted increasing research interest. This paper presents a critical overview of the current techniques employed for iron recovery from red mud. Information on the recovery of other valuable metals is also reviewed to provide an insight into the full potential usage of red mud as an economic resource rather than a waste. Traditional hydrometallurgy and pyrometallurgy are being investigated continuously. However, in this review several new techniques are introduced that consider the process of iron recovery from red mud. An integrated process which can achieve multiple additional values from red mud is much preferred over the single process methods. The information provided here should help to improve the future management and utilization of red mud.     

超临界二氧化碳在环境保护中的应用

超临界CO2具有气体的低粘度、高扩散系数和液体的高密度特性，且具有化学惰性，无毒、无腐蚀性，临界状态容易实现，是一种性能优良的环境友好溶剂。文章概述了超临界CO2在去除环境污染物、取代传统工艺助剂或溶剂以减少有机物和废水排放以及分析测试等方面的应用。     

Recycling of waste biomass and mineral powder for preparation of potassium-enriched compost

An attempt was made to recycle waste biomass and mineral powder (waste mica) as an alternative source of potassium (K) through composting technology. Two different waste biomass, isabgol straw and palmarosa distillation waste along with two levels of waste mica (2 and 4% as K) were used for preparation of enriched composts. A notable decrease of C:N ratio was observed at the end of the composting (150 days) as an indicator of compost maturity. The mature composts were evaluated for K-supplying capacity through laboratory leaching and soil incubation study. Significantly higher water-soluble K released initially followed by a sharp decrease up to 21 days of leaching thereafter gradually decreased up to 35 days of leaching. Water-soluble K was released from K-enriched (mica charged) compost significantly higher than the ordinary compost throughout the leaching period. Soil incubation study also revealed that application of K-enriched compost greatly improved the available K (water soluble and exchangeable) pools in K-deficient soil which indicated that a considerable amount of K releases during composting. Therefore, K-enriched compost could be an effective alternative of costly commercial K fertilizer and eco-friendly approach to utilize low-cost waste mineral powder and plant residue.     

GIS-based modelling for the estimation of municipal solid waste generation and collection

In the present paper, an innovative model for the estimation of municipal solid waste generation and collection is proposed. This model is part of an extended solid waste management system and uses a spatial Geodatabase, integrated in a GIS environment. It takes into consideration several parameters of waste generation, such as population density, commercial activities, road characteristics and their influence on the location and allocation of waste bins. Ground-based analysis was applied for the estimation of the inter-relations between the aforementioned factors and the variations in waste generation between residential and commercial areas. Therefore, the proposed model follows a unified categorization approach for residential and commercial activities and focuses on the dominant factors that determine waste generation in the area under study. The most important result of the research work presented in the current paper is an accurate estimation of the optimal number of waste bins and their allocation. A new methodology and an appropriate algorithm have been developed for this purpose in order to facilitate routing and waste collection. By using these results, municipalities aware of social, economical and environmental factors, related to waste management, can achieve optimal usage of their resources and offer the best possible services to their citizens.     

Recycling extruded polystyrene by dissolution with suitable solvents

The amount of extruded polystyrene (XPS) waste has increased in recent years due to the increase of its use in the thermal insulation of buildings, transport vehicles, and refrigerators, among others. Dissolution with suitable solvents to achieve a volume reduction of more than 100 times without degradation of polymer chains is one of the cheapest and most efficient methods of recycling XPS. Several environmentally friendly solvents have been tested as dissolution agents for XPS volume reduction; the action of these solvents does not produce any degradation of polymer chains. The solubility of the polymer in such solvents at different temperatures was investigated. The solvent can be easily recycled by distillation, obtaining a high-quality recycled polymer. Chemical Feedstock Recycling & Other Innovative Recycling Techniques 6     

Catalytic conversion of waste tyres into valuable hydrocarbons

Tyre recycling has become a necessity because of the huge piles of tyres that represent a threat to the environment. The used tyres represent a source of energy and valuable chemical products. Waste tyres were pyrolysed catalytically in a batch reactor under atmospheric pressure. Calcium carbide was used as a catalyst to explore its effect on pyrolysis product distribution. The effect of temperature, amount of catalyst and time on the yields of the pyrolysed products was investigated. Char yield decreased with increase of pyrolysis temperature while total gas and liquid yields increased. The liquid fraction was obtained with boiling point up to 320 °C. The physical and chemical properties of the pyrolysed products obtained were characterized. The catalytic pyrolysis produced 45 wt.% aromatic, 35 wt.% aliphatic and 20 wt.% of polar hydrocarbons. The distillation data showed that ∼80% of oil has boiling point below 270 °C which is the boiling point for 50% of distilled product in commercial diesel oil. The oil fraction was found to have high gross calorific value; GCV (42.8 MJ kg⁻¹). Its Specific gravity, viscosity, Kinematic viscosity, freezing point and diesel index were also within the limits of diesel fuel. The char residues were studied to investigate their characteristics for use as a possible adsorbent. Surface area of char before and after acid demineralization was determined to determine the adsorptive features for waste water treatment.     

Multiple use of waste catalysts with and without regeneration for waste polymer cracking

Waste plastics contain a substantial number of valuable chemicals. The wastes from post-consumer as well as from industrial production can be recycled to valuable chemical feedstock, which can be used in refineries and/or petrochemical industries. This chemical recycling process is an ideal approach in recycling the waste for a better environment. Polymer cracking using a laboratory fluidised bed reactor concentrated on the used highly contaminated catalyst, E-Cat 2. Even though E-Cat 2 had low activity due to fewer acid sites, the products yielded were similar with amorphous ASA and were far better than thermal cracking. The high levels of heavy metals, namely nickel and vanadium, deposited during their lifetime as an FCC catalyst, did not greatly affect on the catalyst activity. It was also shown that E-Cat 2 could be used with and without regeneration. Although there was more deactivation when there was no regeneration step, the yield of gases (C₂-C₇) remained fairly constant. For the first time, these results indicate that “waste” FCC catalyst (E-Cat) is a good candidate for future feedstock recycling of polymer waste. The major benefits of using E-Cat are a low market price, the ability to tolerate reuse and regeneration capacity.     

An overview on olive mill wastes and their valorisation methods

Olive mill wastes represent an important environmental problem in Mediterranean areas where they are generated in huge quantities in short periods of time. Their high phenol, lipid and organic acid concentrations turn them into phytotoxic materials, but these wastes also contain valuable resources such as a large proportion of organic matter and a wide range of nutrients that could be recycled. In this article, recent research studies for the valorisation of olive mill wastes performed by several authors were reviewed: second oil extraction, combustion, gasification, anaerobic digestion, composting and solid fermentation are some of the methods proposed. Special attention was paid to the new solid waste generated during the extraction of olive oil by the two-phase system. The peculiar physicochemical properties of the new solid waste, called two-phase olive mill waste, caused specific management problems in the olive mills that have led to the adaptation and transformation of the traditional valorisation strategies. The selection of the most suitable or appropriate valorisation strategy will depend on the social, agricultural or industrial environment of the olive mill. Although some methods are strongly consolidated in this sector, other options, more respectful with the environment, should also be considered.     

Enzymatic hydrolysis of organic waste materials in a solid-liquid system

In the current climate of increasing emphasis on environmental protection and efficient waste management, regional management bodies and environmental agencies are striving to achieve an economical and environmentally acceptable system for the recycling of biodegradable organic wastes. Composting would appear to be a cost effective solution to this problem, but in its entirety, composting is an inherently lengthy and variable process and is restrictive in terms of the demand on resources and space in composting plants. The aim of this study was to compare a biological composting process of solid residues with an enzymatic hydrolysis process of residues. The length of time required to naturally compost three organic materials, spent mushroom compost (SMC), farmyard manure (FYM) and dairy wastewater sludge (DWS) under optimal conditions was 42 days, 98 days and 84 days, respectively. In an attempt to accelerate this process, commercial enzymes were added to the waste products in a heterogeneous solid-liquid system. The enzymes utilised included a range of proteases, cellulases, ligninases, lipases and pectinases, which are responsible for the hydrolysis of protein, cellulose, lignin, lipids and carbohydrates, respectively. Preliminary results indicate that all of the organic materials were stabilised within 9h and that the enzymes used would, therefore, improve the efficiency of a waste management plant, if such a system were employed. Spent mushroom compost has a mean N/P/K ratio of 20:10:10 recorded for composted SMC, while a similar ratio of 20:10:20 was obtained for hydrolysed SMC. In contrast, composted farmyard manure has a N/P/K ratio of 30:0:30 and a ratio of 10:1:10 for hydrolysed FYM. Finally, composted DWS has a N/P/K ratio of 20:1:30 while DWS hydrolysate has a N/P/K ratio of 40:1:20, with the decrease in nitrogen in the composted DWS attributed to the addition of wood chippings and sawdust as a bulking agent. While all three materials have a considerable supply of plant nutrients, the variability in nutrients could be overlooked when employed as a soil amendment.     

应用特殊精馏技术从制药废液中回收四氢呋喃

研究了萃取精馏技术和反应萃取精馏技术在回收四氢呋喃（ＴＨＦ）中的应用,选择了萃取剂和反应萃取剂,设计了工艺流程,优化了操作条件,试验结果表明,采用以上技术从制药废液中回收的ＴＨＦ,纯度可达到９９．４％。