A preliminary process design and economic assessment of a catalyst rejuvenation process for waste disposal of refinery spent catalysts

Spent hydroprocessing catalysts from refineries have been classified as hazardous solid waste by the United States Environmental Protection Agency (USEPA), refiners must find a viable but economical solution to solve this serious environmental issue. Catalyst rejuvenation is an attractive option for minimizing the environmental problems associated with spent catalysts. In this study, a preliminary design for such a process and the corresponding economic analysis are performed to assess the proposed catalyst rejuvenation process for metal-fouled spent catalysts generated in residue hydroprocessing units. The scenarios used in the economic assessment are based on three options of process synthesis and two operator modes. It is found that the option of rejuvenating medium and lightly fouled spent catalyst produced by the refinery will be the best solution for refiners, both environmentally and economically.     

An Eco-balance of a Recycling Plant for Spent Lead–Acid Batteries

This study applies Life Cycle Assessment (LCA) methodology to present an eco-balance of a recycling plant that treats spent lead–acid batteries. The recycling plant uses pyrometallurgical treatment to obtain lead from spent batteries. The application of LCA methodology (ISO 14040 series) enabled us to assess the potential environmental impacts arising from the recycling plants operations. Thus, net emissions of greenhouse gases as well as other major environmental consequences were examined and hot spots inside the recycling plant were identified. A sensitivity analysis was also performed on certain variables to evaluate their effect on the LCA study. The LCA of a recycling plant for spent lead–acid batteries presented shows that this methodology allows all of the major environmental consequences associated with lead recycling using the pyrometallurgical process to be examined. The study highlights areas in which environmental improvements are easily achievable by a business, providing a basis for suggestions to minimize the environmental impact of its production phases, improving process and company performance in environmental terms.     

ENVIRONMENTAL IMPACT EVALUATION OF HAZARDOUS WASTE DISPOSAL IN LAND1

Since the publication of Rachel Carson's Silent Spring in 1962 there has been a rapidly growing public concern over widespread contamination of the environment with hazardous wastes. In recent years scientific findings on the ecological effects of various hazardous substances have posed several important questions. What exactly are hazardous wastes? Can these substances be disposed of in a technically feasible, economical, and safe way with assurance that they have been permanently eliminated from the ecosystem? What compositional alterations or movements of the hazardous wastes occur in water, soil, or air systems? What effect will these wastes have on the water, soil, or air systems? What effect will these wastes have on the water, soil, or air properties? Consequently, a University of Louisville study has developed a relevant definition of hazardous wastes for the Environmental Engineering profession together with priority of concern rating systems to delineate the degree of environmental impact imposed on a total ecosystem by a hazardous waste and the feasibility of disposing of hazardous substances at specific landfill sites. It is felt that refinements of the priority of concern rating systems offered here may provide a sound basis from which procedural decisions may be structured to establish future national hazardous waste disposal sites.     

Recovery of biomass wastes by hydrolysis in sub-critical water

The recovery of waste substances is important not only for the prevention of environmental issues, but also for the rational utilization of natural resources. Hydrolysis reaction in sub-critical water is a promising method for the treatment of organic wastes and has been attracting worldwide attention. In this paper, sub-critical water hydrolysis was employed as a method for producing amino acids, reducing sugars, bio-oil and gas fuels from biomass wastes. The current statuses of these useful chemicals production from biomass wastes by hydrolysis in sub-critical water were reviewed. The review indicates that sub-critical water hydrolysis can be an efficient process for recovering useful chemicals from biomass wastes. This method is renewable, sustainable, efficient, and safe for the environment.     

Cadmium—Towards a rational use of a toxic element

Because of its toxicity, cadmium creates an environmental problem as well as a health hazard for exposed workers. Most cadmium emissions arise from the intentional use of the element. It is therefore mandatory to reduce cadmium consumption to the lowest possible level. Cadmium pigments, mainly used in plastic processing, can be replaced in all applications where the processing temperature does not exceed 300°C. Newly developed polyvinyl chloride stabilizers promise to be an excellent substitute for cadmium stabilizers in even the most demanding applications. Cadmium plating, still extensively used in the United States and the West Germany, has been virtually abandoned in Japan. Improved lead acid batteries are replacing vented nickel cadmium batteries because of their cost effectiveness. While in these applications cadmium use is declining, more and more cadmium is needed for the manufacturing of sealed nickel cadmium batteries. These relatively small electrochemical cells are used mainly by individual consumers. Here cadmium can only be replaced in some marginal applications. The high cadmium content of these batteries (up to 22%) makes them a good candidate for recycling of the heavy metal.     

Life cycle inventory of recycling portable nickel–cadmium batteries

In this study, the environmental impact of recycling portable nickel–cadmium (NiCd) batteries in Sweden is evaluated. A life cycle assessment approach was used to identify life cycle activities with significant impact, the influence of different recycling rates and different time boundaries for emissions of landfilled metals. Excluding the user phase of the battery, 65% of the primary energy is used in the manufacture of batteries while 32% is used in the production of raw materials. Metal emissions from batteries to water originate (96–98%) from landfilling and incineration. The transportation distance for the collection of batteries has no significant influence on energy use and emissions. Batteries manufactured with recycled nickel and cadmium instead of virgin metals have 16% lower primary energy use. Recycled cadmium and nickel metal require 46 and 75% less primary energy, respectively, compared with extraction and refining of virgin metal. Considering an infinite time perspective, the potential metal emissions are 300–400 times greater than during the initial 100 years. From an environmental perspective, the optimum recycling rate for NiCd batteries tends to be close to 100%. It may be difficult to introduce effective incitements to increase the battery collection rate. Cadmium should be used in products that are likely to be collected at the end of their life, otherwise collection and subsequent safe storage in concentrated form seems to offer the best solution to avoid dissipative losses.     

含镍废液中镍回收的研究

本文研究了强碱性条件下,以乙二胺为络合剂,用水合肼把二价镍离子还原为单质镍的方法。经过大量实验,镍粉的产率在99％以上,其纯度也在99％以上。通过这种方法,既回收了镍,又降低了对环境的污染,结果令人满意。     

Recycling of spent lead/acid batteries: the case of Greece

In this study, the application of modern recycling technologies in accordance with the European and Greek legislation, aiming at the recovery of lead, polypropylene and sulfuric acid from spent lead (Pb)/acid batteries, is presented. The present state of their disposal and exploitation is also depicted. The international situation is reviewed, the general trends are marked and the main technologies related to lead/acid battery treatment are reported. General recommendations are given regarding the collection of spent batteries and the installation of a recycling plant in Greece. A sensitivity analysis is carried out in order to define the most significant parameters affecting the viability of a recycling scheme. The present study proves that a possible installation of a Pb/acid batteries recycling process unit, treating 17 000 t/year (estimated total quantity) and situated in the industrial area of the greater Athens region, seems to be economically profitable. The already existing operation of small-scale battery recycling plants, common in small countries, should be discouraged as they demonstrate a rather not environmentally acceptable recycling operation.     

Recovery of foundry sands and iron fractions from an industrial waste landfill

This study was performed to analyse the technical and economical feasibility of a project concerning the recovery of foundry wastes from a landfill. In such a context, an evaluation of the total amount of residues that could be recovered was performed by using the physical chemical characterization of landfilled wastes: molding and core sands, furnace dusts, finishing dusts, muds, calcium hydroxide and refractory slags. Field tests were realized employing both geophysical methods both the digging of trenches.Two cells of the landfill were investigated by means of geophysical methods using magnetic and electromagnetic techniques. The physical and chemical characterization of wastes was employed in order to determine the best geophysical methods to locate the useful fractions of wastes in landfill and to establish the occurring treatment cycle for the recovery of useful fractions.A cost–benefit analysis was performed to evaluate the feasibility of the proposed landfill mining operation.     

石油加工与石油化工废料应用于钻井液

石油加工与石油化工废料，包括废白土、酸渣、碱渣、渣油、油泥、生产润滑油添加剂的废料、废催化剂、环烷酸釜残等，在钻井液中的用途较广，可以分别用作钻井液原始组分和润滑剂、消泡剂、多效防塌剂、抑制剂、稳定剂、废钻井液固化剂以及制备这些处理剂的基础材料。文中介绍了前苏联及独联体等在这方面的研究成果和现场应用情况。     

A mechanical pre-treatment process for the valorization of useful fractions from spent batteries

In this paper the authors propose a full-scale plant aimed to pre-treat spent batteries in order to obtain cleaned useful fractions (magnetic and non-magnetic metals, paper, plastic, a fine-sized material made of a metal-carbon mixture). The treating process was designed after having analyzed and tested a representative sample coming from the whole amount of spent batteries collected in 1 month by the public service in and around Turin. The analyses performed on the sample allowed the authors to determine its in-percentage composition in term of type of batteries: 60-70% b.w. (by weight) alkaline, 25-30% b.w. Zn-C and 5-10% b.w. other types. For each type, the composition in term of size (AAA or LR03; AA or LR6; C or LR14; D or LR20; 9 V or 6F22A; 4.5 V or 3R12A) has also been determined.The treatment for the recovery of secondary raw materials foresees the following phases:

-

separation of useful types/sizes of exhaust batteries to undergo further treatments by means of a first sieving process;

-

liberation of the single components taking advantage of a crushing operation;

-

separation of a fine-sized material (to subject to pyro or hydro metallurgic recovery) from a coarse-sized material (to send to secondary smelt foundries and incinerators) by means of a second sieving phase.

On the basis of the results obtained from the crushing/sieving laboratory tests and the chemical characterization, a full-scale plant able to treat about 76,000 t/y of spent batteries has been designed. The cost analysis performed on the proposed treatment plant has given back a unit pre-treatment cost equal to 3€ per ton of processed spent batteries.     

重庆含铜废物利用行业技术准入研究

因缺失含铜废物利用技术准入规范,从业企业良莠不齐,制约了该行业的良性发展。通过分析重庆市含铜废物利用现状、存在问题,从含铜废物利用项目选址用地、建设规模、产品质量、技术工艺、设施建设、准入许可及环境管理等方面提出准入门槛规定,以期为含铜废物利用行业良性发展提供参考。     

Industrial waste to energy by circulating fluidized bed combustion

Industrial waste is a good resource from the viewpoint of efficient waste management. The vital need for energy utilization and environmental protection mean it is of interest to develop circulating fluidized bed combustion (CFBC) to burn solid wastes with low pollutant emissions. The paper presents some explanatory studies on waste-to-energy in a pilot scale CFCB facility. A series of combustion/incineration tests have been carried out for the industrial wastes: petroleum coke, waste tire and sludge cakes with various moisture contents. It seems that the CFBC has feed flexibility without modifying heat transfer equipments for energy recovery. In addition, the results of experimental tests demonstrate that gas emissions from waste incineration in CFBC can be well controlled under local regulation limits.At normal operation temperature in CFBC (approx. 800°C), the heat transfer coefficient between bulk bed and bed wall is on the order of 10² W/m^2° C, which is useful to estimate the energy recovery of waste combustion by CFBC. A practical and simple guide is proposed to estimate the energy recovery from waste combustion by CFBC, and to find maximum allowable moisture content of waste if there is to be any energy recovery without auxiliary fuel.     

Selective dissolution of critical metals from diesel and naptha spent hydrodesulphurization catalysts

The petroleum refining industry makes extensive use of catalysts, containing critical metals, such as, Mo, Co and Ni, for the desulphurization of various oil fractions. The selective recovery of these metals from two uncrushed and at low temperature calcined industrial hydrodesulphurization (Mo---Co/Al₂O₃ and Mo---Ni/Al₂O₃---SiO₂) catalysts was studied, applying a two-step alkali-acid procedure. Fundamental kinetic aspects of the process, such as, reaction time, leaching reagents concentration and reaction temperature, were studied. Recoveries up to 97% for Mo and up to 92% for Co or Ni in separate solutions were achieved, using low cost and easily available reagents, such as sodium hydroxide and sulphuric acid.     

中国控制危险废物越境转移管理现状与展望

按照环境无害化管理原则,严格限制危险废物越境转移活动是中国履行《控制危险废物越境转移及其处置巴塞尔公约》的重要内容。本研究通过梳理《控制危险废物越境转移及其处置巴塞尔公约》关于控制危险废物越境转移的主要规定和中国立法管理实践,全面分析了中国控制危险废物越境转移管理进展。从打击非法转移、完善法律基础、建立预警机制等方面,深入剖析了中国控制危险废物越境转移面临的形势,并从强化危险废物越境转移管控、严厉打击非法出口行为、联合海关部门加强日常监管三方面提出对策建议,以期为中国全面履行《控制危险废物越境转移及其处置巴塞尔公约》要求、控制和防范危险废物越境转移环境风险提供支撑。     

Heavy metal removal and cyanide destruction in the metal plating industry: an integrated approach from egypt

Wastewater produced from a metal plating is a major environmental problem. Industrial auditing revealed that the main source of pollution mainly originated from rinsing water. The characterization of final effluent showed that it is highly contaminated with hazardous heavy metals and cyanide. The concentration of copper, hexavalent chromium, nickel, and cyanide in the rinsing water of metal plating department was 14.8, 40.9, 13.3, and 19 mg/l, respectively. The concentration of cyanide and zinc from the galvanizing department reached 60 and 80 mg/l. The remediation scheme included the application of in-plant control measures via changing the rinsing process followed by the destruction of cyanide and reduction of hexavalent chromium bearing wastes. The pretreated wastes were then mixed with other industrial wastes prior to a combined chemical coagulation-sedimentation using lime and/or lime in combination with ferric chloride. The results indicated that, after applying the waste minimization measures alone at the source, prior to final treatment of industrial waste, removal rates of cyanide, copper, nickel, and chromium concentrations were 23.2%, 14.9%, 32.3%, and 55.3%, respectively in the rinse water from metal plating department. Furthermore, the removal rates of cyanide and zinc in the galvanizing department reached 59.7% and 24.3. The integrated control measures and treatment scheme led to more than 99% removal of copper, nickel, chromium, and zinc, while the complete removal of cyanide was achieved in the final effluent.     

Environmental management aspects for TBT antifouling wastes from the shipyards

Tributyltin (TBT)-based antifouling paints have been successfully used for over 40 years to protect a ship's hull from biofouling. However, due to its high toxicity to marine organisms, the International Maritime Organization (IMO), in 1990, adopted a resolution recommending governments to adopt measures to eliminate antifouling paints containing TBT. High concentrations of TBT are detected in the vicinity of ports and shipyards. TBT is also usually detected in the sediment, in which it accumulates. This study reviews recent literature for the best management practices (BMPs) in order to minimize the environmental effects of TBT. The paper focuses on the evaluation of the available techniques for the removal of TBT from shipyard wastes and from the sediment. The most effective treatment methods are highlighted. BMPs include recycling of abrasive materials, use of cleaner abrasive materials, reuse of spent abrasive materials, substitution of hydroblasting by vacuum blasting or containment or ultra-high-pressure water blasting and confinement of pollution by enclosure and containment systems. The treatment of the TBT wastes by conventional biological wastewater treatment processes is probably not suitable, because the concentrations of TBT found in shipyards' wastewaters are toxic to microorganisms. Advanced technologies such as activated carbon adsorption and dissolved air flotation, in combination with filtration and coagulation-clarification, photodegradation and electrochemical treatment, are required to remove TBT. However, advanced methods should be further optimized to meet the regulatory limit of 200 ng/L. To date, only one published work examines the efficiency of incineration for the treatment of solid sandblast wastes. Regarding the treatment of sediment, land deposition of the less polluted fraction of sediment is a feasible option. Such treatment must take into account the risk of contamination of groundwater and the surroundings, and it requires extended areas of land. Other treatment methods, such as thermal and electrochemical treatment, are promising options but due to the large amounts of dredged material, they have high capital and operational costs.     

Technological improvements in automotive battery recycling

Recycling of automotive batteries for the recovery of secondary lead is extremely important in Brazil, for the country does not possess large reserves of this metal. Lead is one of the most widely used metals in the world, but it is highly toxic, posing risks for humans and for the environment if not utilized or treated adequately. Industrial waste containing lead in Brazil are classified by the Brazilian Residue Code (NBR—10004:2004) as hazardous. The lead recycling process employed by the recycling industry in Brazil is the pyrometallurgical process in a rotary furnace. This process consists of four stages: (1) grinding of the battery to separate plastic, electrolyte and lead plates; (2) lead reduction in a rotary furnace; (3) separation of metallic lead from slag; and (4) refining of recycled lead. The purpose of this work is to propose process improvements aimed primarily at increasing production output by reducing the loss of lead in slag and particulates, thereby providing a healthier work environment in line with Brazilian environmental and labor laws.     

Development of a highly sensitive extractive spectrophotometric method for the determination of nickel(II) from environmental matrices using N-ethyl-3-carbazolecarboxaldehyde-3-thiosemicarbazone

Nickel(II) reacts with N-ethyl-3-carbazolecarboxaldehyde-3-thiosemicarbazone (ECCT) and forms a yellow colored complex, which was extracted into n-butanol from sodium acetate and acetic acid buffer at pH 6.0. The absorbance value of the Ni(II)-ECCT complex was measured at different intervals of time at 400nm, to ascertain the time stability of the complex. The extraction of the complex into the solvent was instantaneous and stable for more than 72h. The system obeyed Beer's law in the concentration range of 1.2-5.6mugml(-1) of nickel(II), with an excellent linearity and a correlation coefficient of 0.999. The molar absorptivity and Sandell's sensitivity of the extracted species were found to be 1.114x10(4)Lmol(-1)cm(-1) and 5.29x10(-3)mugcm(-2) at 400nm, respectively. Hence, a detailed study of the extraction of nickel(II) with ECCT has been undertaken with a view to developing a rapid and sensitive extractive spectrophotometric method for the determination of nickel(II) when present alone or in the presence of diverse ions which are usually associated with nickel(II) in environmental matrices like soil and industrial effluents. Various standard alloy samples (CM 247 LC, IN 718, BCS 233, 266, 253 and 251) have been tested for the determination of nickel for the purpose of validation of the present method. The results of the proposed method are comparable with those from atomic absorption spectrometry and were found to be in good agreement.     

Current and emerging technologies for extending the lifetime of electroless nickel plating baths

The waste treatment and rejuvenation of spent electroless nickel baths has attracted a considerable amount of interest from electroplating shops, electroless nickel suppliers, universities and regulatory agencies due to the finite life of the baths and the associated waste that the process generates. It is generally accepted that the recycling of electroless nickel solutions is one of the most important challenges facing the electroless nickel-plating industry today. This review presents an overview of the existing and emerging technologies for extending the life of electroless nickel baths. The electroless nickel bath regenerative technologies are appraised from the standpoint of removal of harmful bath components, loss of valuable bath components, cost-effectiveness, secondary waste generation and ease of implementation. The review draws upon an array of academic papers, industrial/company reports, conference proceedings and patents in order to allow the reader to evaluate and compare the different technologies and options for extending the life of electroless nickel-plating solutions.