Burning Chemical Wastes as Fuels in Cement Kilns

Hazardous wastes in the environment represent one of our most serious problems. Ever increasing quantities of toxic wastes have contaminated our land, air, and water. Lack of adequate hazardous waste disposal facilities is a critical problem. Landfilling toxic wastes is no longer considered safe. The tragedy of the Love Canal has demonstrated the need for proper hazardous waste disposal facilities. The best organic chemical waste disposal method is process incineration. Cement kilns have been used for burning toxic chemical industrial wastes in Canada, Michigan, New York, Sweden, etc. Existing cement kilns, when properly operated, can destroy most organic chemical wastes. Even the most complex chlorinated hydrocarbons, including PCB can be completely destroyed during normal cement kiln operations, with minimal emissions to the environment. Burning toxic chemical wastes in cement kilns, and other mineral industries, is mutually beneficial to both industry, who generates such wastes, and to society and government, who want to dispose properly of such wastes in a safe, environmentally acceptable manner. The added benefit of energy conservation is important, since large quantities of valuable fuel can be saved in the manufacture of cement when such techniques are employed.     

Conversion of chromium-containing solid wastes into value-added products through a plasma-assisted aluminothermic process

Chromium-containing solid wastes have been generated by chemical and leather/tanning industries, and the management and proper disposal of the same wastes have been challenging tasks. A significant fraction of these wastes contains chromium compounds with chromium present in the hexavalent (Cr⁺⁶) form, which is hazardous to human beings, animals, and ecosystems. Since these wastes are discarded largely without proper treatments, soil and groundwater get contaminated and they can cause several health issues to human beings. Conventional methods developed to convert hazardous Cr⁶⁺ to Cr³⁺/Cr metal either generate secondary toxic wastes and unwanted by-products and/or are time-consuming processes. In this work, a plasma-assisted aluminothermic process is developed to convert the toxic waste into non-toxic products. The waste was mixed with aluminium powder and subjected to transferred arc plasma treatment in a controlled air atmosphere. Chemical analysis and Cr leachability studies of the waste material prior to plasma treatment have shown that it is highly toxic. Analysis of the products obtained from the plasma treatment showed that Cr and Fe present in the waste could be recovered as a metallic mixture as well as oxide slag, which were found to be non-toxic. Easy separation of the metallic fraction and the slag from the treated product is one of the merits of this process. Besides converting chromium-containing toxic waste to non-toxic materials, the process is rapid and recovers the metals from the waste completely.

     

Treatment Technologies For Hazardous Wastes: Part IV A Review of Alternative Treatment Processes for Metal Bearing Hazardous Waste Streams

The U.S. Congress and the U.S. Environmental Protection Agency believe that treatment and recovery techniques should be given maximum priority when considering methods for managing the nation's generated hazardous waste. A prohibition for the disposal of certain categories of hazardous wastes either directly onto or into the land without being treated to an accepted degree prior to such disposal practice has been promulgated.¹ Wastes containing toxic metals and cyanide complexes have been selected as a group to be restricted. Due to the high generation rate associated with this category, a large capacity of waste treatment processing will be required. Existing and emerging treatment alternatives which are or have the potential to be employed for waste treatment of metal bearing wastes are presented in this paper.     

Automated Economic Analysis Model For Hazardous Waste Minimization

Abstract

The U.S. Army has established a policy of achieving a 50 percent reduction in hazardous waste generation by the end of 1992. To assist the Army in reaching this goal, the Environmental Division of the U.S. Army Construction Engineering Research Laboratory (USACERL) designed the Economic Analysis Model for Hazardous Waste Minimization (EAHWM). The EAHWM was designed to allow the user to evaluate the life cycle costs for various techniques used in hazardous waste minimization and to compare them to the life cycle costs of current operating practices. The program was developed in C language on an IBM compatible PC and is consistent with other pertinent models for performing economic analyses. The potential hierarchical minimization categories used in EAHWM Include source reduction, recovery and/or reuse, and treatment. Although treatment is no longer an acceptable minimization option, its use is widespread and has therefore been addressed in the model. The model allows for economic analysis for minimization of the Army’s six most important hazardous waste streams. These include, solvents, paint stripping wastes, metal plating wastes, industrial waste-sludges, used oils, and batteries and battery electrolytes. The EAHWM also includes a general application which can be used to calculate and compare the life cycle costs for minimization alternatives of any waste stream, hazardous or non-hazardous. The EAHWM has been fully tested and implemented in more than 60 Army installations in the United States.     

Siting Ambient Air Particulate Samplers Near Dirt Roads

There are economic and regulatory incentives for considering alternatives to the direct land disposal of solvent-bearing hazardous waste streams (EPA Hazardous Waste Codes: F001, F002, F003, F004, and F005). These alternatives include recycle/reuse (including use as a fuel substitute), destruction of a stream's solvent component, and treatment prior to land disposal. This paper reviews these three waste management alternatives and discusses their applicability to solvent waste streams having various physical characteristics. Seven waste treatment techniques which may be used to handle solvent wastes are described: incineration, agitated thin-film evaporation, fractional distillation, steam stripping, wet oxidation, carbon adsorption, and activated sludge biological treatment.     

Medical Waste Treatment and Disposal Methods Used by Hospitals in Oregon,Washington, and Idaho

ABSTRACT

This study investigated medical waste practices used by hospitals in Oregon, Washington, and Idaho, which includes the majority of hospitals in the U.S. Environmental Protection Agency's (EPA) Region 10. During the fall of 1993, 225 hospitals were surveyed with a response rate of 72.5%. The results reported here focus on infectious waste segregation practices, medical waste treatment and disposal practices, and the operating status of hospital incinerators in these three states. Hospitals were provided a definition of medical waste in the survey, but were queried about how they define infectious waste. The results implied that there was no consensus about which agency or organization's definition of infectious waste should be used in their waste management programs. Confusion around the definition of infectious waste may also have contributed to the finding that almost half of the hospitals are not segregating infectious waste from other medical waste. The most frequently used practice of treating and disposing of medical waste was the use of private haulers that transport medical waste to treatment facilities (61.5%). The next most frequently reported techniques were pouring into municipal sewage (46.6%), depositing in landfills (41.6%), and autoclaving (32.3%). Other methods adopted by hospitals included Electro-Thermal-Deac-tivation (ETD), hydropulping, microwaving, and grinding before pouring into the municipal sewer. Hospitals were asked to identify all methods they used in the treatment and disposal of medical waste. Percentages, therefore, add up to greater than 100% because the majority chose more than one method. Hospitals in Oregon and Washington used microwaving and ETD methods to treat medical waste, while those in Idaho did not. No hospitals in any of the states reported using irradiation as a treatment technique. Most hospitals in Oregon and Washington no longer operate their incinerators due to more stringent regulations regarding air pollution emissions. Hospitals in Idaho, however, were still operating incinerators in the absence of state regulations specific to these types of facilities.     

Afriwaste The fixation and stabilisation of hazardous waste

The disposal of hazardous and toxic wastes is an area where utmost care and responsibility needs to be exercised. A certain (and mostly acceptable) level of care and responsibility has been legislated and is in place in most developed economies (UK, USA, Canada, Europe, etc.). This is, however, generally not the case in under-developed or developing economies, South Africa being no exception. This paper reflects on various disposal methods and describes a potentially economic alternative to existing methods of the disposal of toxic and hazardous wastes. These existing methods are: Disposal in Class I landfill sites and destruction via incineration.     

Treatment Technologies For Hazardous Wastes: Part III Treatment Technologies for Corrosive Hazardous Wastes

In this paper, the authors present generation and treatment information for corrosive hazardous wastes (EPA Hazaradous Waste Codes D002 and K062). The authors discuss the state of the art for several treatment trains used to process specific types of corrosive waste. Treatment trains incorporate various unit processes selected from but not limited to the following: neutralization, filtration, carbon adsorption, biological oxidation, distillation, air flotation, and incineration. Unit processes are selected to form trains according to the corrosive characteristics of each individual waste stream. The treatment processes discussed are proposed to be used instead of landfills for disposal of corrosive waste.     

Molten salt oxidation: a versatile and promising technology for the destruction of organic-containing wastes

Molten salt oxidation (MSO), a robust thermal but non-flame process, has the inherent capability of destroying organic constituents in wastes, while retaining inorganic and radioactive materials in situ. It has been considered as an alternative to incineration and may be a solution to many waste disposal problems. The present review first describes the history and development of MSO, as well as design and engineering details, and then focuses on reaction mechanisms and its potential applications in various wastes, including hazardous wastes, medical wastes, mixed wastes, and energetic materials. Finally, the current status of and prospects for the MSO process and directions for future research are considered.     

Incineration of hazardous wastes from the petroleum industry in Nigeria

Persistent hazardous wastes are produced in the recovery, processing and upgrading of crude petroleum in Nigeria. However, recent developments in environmental pollution control are drawing increasing attention to the problems of hazardous wastes. The ever-increasing need to control these wastes from the petroleum industry often compels the chemical engineer to specify methods of treatment and disposal. Present methods for disposal are becoming increasingly undesirable for a number of reasons, and incineration is being considered as an alternative. This paper reviews the extent of hazardous waste generation from the Nigerian petroleum industry and its environmental implications. It also examines the current disposal methods and the incineration technology option. The major chemical engineering concepts of the incineration process and the principles guiding their operations are discussed. The potential for the use of incineration is examined, as well as information that would aid the choice of incineration system for new applications.     

The Use of Electrostatic Precipitators on Municipal Incinerators

Despite this country’s scientific advances, most communities in the United States are still disposing of solid wastes the way they did 50 years ago. The problem is advancing faster than the solution. Less than half the cities in this country with populations over 2500 dispose of their wastes by an approved sanitary and nuisance-free method. Do you realize that every 60 seconds people in the United States drop 251 tons of trash into their garbage cans. At the end of the day, 362,000 tons have accumulated. This means each of the 190 million people in the US disposes of 43½ lb of rubbish daily. By the year 2000 population is expected to double, while the per capita rate of increase in refuse production rises about 2% annually.

As the population booms and spreads to the suburbs, and suburbs expand into further suburbs, we will rapidly use up the land once used for waste disposal. Thus, sanitary landfill sites will disappear because by the year 2000 three-fourths of our population will live in urban areas.

The answer to this enormous problem faced by large and small communities is central incineration. Only this system can provide a maximum reduction in the volume of refuse. It is for this reason that communities are turning to incineration as the best solution. However, a growing public awareness plus changing municipal, state, and federal laws necessitate the need for a modern incineration plant that incorporates the most advanced and proved method of air pollution control. Where efficiencies of 60 to 80% were acceptable in the past, 90 to 95% are sought at present, and soon 96 to 99% will be required.

This paper deals with the effective control of particulate emissions from municipal incinerator exhaust gases.     

Public Policy impacts on the Generation and Disposal of Hazardous Waste in New York State

A number of policies adopted by the federal government and the states have been designed to promote waste reduction or influence the choice of waste disposal technologies employed by generators of hazardous waste. Graphic analysis of smoothed time series data for hazardous wastes manifested in New York State for the period between June 1982 and February 1987 suggests that some of these policies have had the intended effects.

Significant shifts in manifested waste volumes are evident that coincide with the following policy interventions: (1) increased state waste-end tax rates; (2) state and federal landfill bans; (3) federal restrictions on burning hazardous wastes and waste oils for energy recovery; and (4) changes in the federal regulatory definition of hazardous waste. Other changes in waste generation and management appear to be attributable to such factors as state and regional economic conditions and changes in instate treatment and disposal facility capacity. Analysis of the management of specific waste types supports evidence from the graphic analysis that waste generators changed from land disposal to “higher” waste handling technologies in response to several policy interventions.     

Application of life cycle assessment for hospital solid waste management: A case study

This study was meant to determine environmental aspects of hospital waste management scenarios using a life cycle analysis approach. The survey for this study was conducted at the largest hospital in a major city of Pakistan. The hospital was thoroughly analyzed from November 2014 to January 2015 to quantify its wastes by category. The functional unit of the study was selected as 1 tonne of disposable solid hospital waste. System boundaries included transportation of hospital solid waste and its treatment and disposal by landfilling, incineration, composting, and material recycling methods. These methods were evaluated based on their greenhouse gas emissions. Landfilling and incineration turned out to be the worst final disposal alternatives, whereas composting and material recovery displayed savings in emissions. An integrated system (composting, incineration, and material recycling) was found as the best solution among the evaluated scenarios. This study can be used by policymakers for the formulation of an integrated hospital waste management plan.

Implications: This study deals with environmental aspects of hospital waste management scenarios. It is an increasing area of concern in many developing and resource-constrained countries of the world. The life cycle analysis (LCA) approach is a useful tool for estimation of greenhouse gas emissions from different waste management activities. There is a shortage of information in existing literature regarding LCA of hospital wastes. To the best knowledge of the authors this work is the first attempt at quantifying the environmental footprint of hospital waste in Pakistan.     

A Comparison of In situ Vitrification and Rotary Kiln Incineration for Soils Treatment

In the hazardous waste community, the term “thermal destruction” is a catchallphrase that broadly refers to high temperature destruction of hazardous contaminants. Included in the thermal destruction category are treatment technologies such as rotary kiln incineration, fiuidized bed incineration, infrared thermal treatment, wet air oxidation, pyrolytic incineration, and vitrification. Among them, conventional rotary kiln incineration, a disposal method for many years, is the most well established, and often serves as a barometer to gauge the relative success of similar technologies. Public sentiment on environmental issues and increasingly stringent environmental regulations has, over time, spurred design and development of innovative thermal treatment processes directed toward reducing harmful emissions and residuals that may require further treatment or disposal. In situ vitrification (ISV), a technology that combines heat and immobiliztion, is one such innovative and relatively new technology.

This paper presents a comparison of ISV and rotary kiln incineration for soils treatment in the areas of process performance, process residuals, process limitations, applicable or relevant and appropriate (ARAJRs) regulations, criteria and limitations, and costs.     

Thermal and Catalytic Incinerators for the Control of VOCs

Abstract

The emission of Volatile Organic Compounds (VOCs) is attracting increasing concern both from the public and by government agencies. Among the many available control technologies for the treatment of VOC containing waste streams, incineration offers an ultimate disposal strategy rather than a means for collecting or concentrating the offending compounds. This paper describes the major, commercially available thermal and catalytic incinerator systems that are designed to treat dilute, VOC containing gas streams. Qualitative guidelines are presented whereby the technologies can be compared. In addition, an example waste stream is used to illustrate a simplified procedure for calculating the material and energy balances for each of the incinerators. The resulting parameters will be used in a companion paper to estimate the capital and operating costs associated with each design. In this manner, a first estimate can be obtained of the costs of cleaning a waste stream containing low levels of VOCs.     

Polymers as Solid Waste in Municipal Landfills

Abstract

Synthetic polymers reach municipal landfills as components of products such as waste household paints, packaging films, storage containers, carpet fibers, and absorbent sanitary products. Some polymers in consumer products that reach landfills are designed to photodegrade or biodegrade. This article examines the significance of degradable polymers in management of solid waste in municipal landfills. Most landfills are not designed to photodegrade or biodegrade solid waste. Landfill disposal of stable polymers such as polyacrylics and polyethylenes is not associated with significant polymer degradation or mobility. Stability to photodegradation and biodegradation is an advantage when municipal landfills are used for disposal of polymer products as solid waste. Use of landfill disposal can be a responsible means to manage polymer waste and can be part of an overall waste management plan which includes source reduction, recycling, reuse, composting, and waste-to-energy incineration.     

Chemical Manufacturers Association 1984 Hazardous Waste Survey

This paper discusses the Chemical Manufacturers Association's 1984 survey of the chemical industry's hazardous waste management practices. The survey data include a breakdown of how the industry's hazardous wastes are managed, detailing generation, treatment and disposal, and cover 725 plants in 81 companies. The 1984 survey is the third CM A hazardous waste survey, and the paper discusses resultant waste treatment trends from 1981- 1984, the period covered by previous surveys. A total of 278.5 million tons of hazardous waste was treated and disposed by survey respondents. Of this, 276.8 million tons was hazardous wastewater and 1.7 million tons was solid hazardous waste. The survey solid hazardous waste total was projected to the entire industry (Standard Industrial Code 2800) and is estimated at 6.9 million tons. The survey showed continued decreasing trends in hazardous waste generation in the chemical industry. It demonstrated changes in hazardous waste management practices, with decreased use of landfills and increased incineration of the solid wastes that are generated.     

医疗废弃物焚烧挥发性氯含量与热值测试与估算

通过测定上海某医疗废弃物处置公司设定燃烧工况条件下某时间段内烟气中HC l的平均排放速率,估算出上海地区医疗垃圾废物中的可燃烧转化氯含量在2.33%~2.64%左右;通过测定各较小采样时间段(2 m in)的烟气HC l浓度测定发现批次进料造成烟气中HC l浓度近4倍的波动,通过初步的热平衡估算得到医疗废弃物的热值大致在21.8 M J/kg,得到的结果可为我国医疗废弃物的焚烧工艺设计提供基础依据。     

苏州市生活垃圾两种处置方法的生命周期影响评价

采用生命周期评价的方法，比较了苏州市垃圾填埋和垃圾焚烧2种处置方法对环境的影响。研究的系统范围主要包括垃圾收集、垃圾运输、垃圾填埋或焚烧以及发电等几个部分。采用收集的垃圾组分数据，利用IPCC推荐的模型等，计算了垃圾填埋和垃圾焚烧时CO₂等气体污染物的排放量。根据对垃圾渗滤液的实测数据，计算了水污染物的排放量。环境影响评价采用日本开发的AIST-LCA Ver4计算机软件进行。计算结果表明：垃圾填埋的生态币值要大得多，可见垃圾焚烧对环境的影响比垃圾填埋的影响要小。所获得的结论较为客观地反映了对环境的影响，可以作为中国城市垃圾处置决策的参考依据。