Disposal Procedures Research Articles

Safe Use of Hazardous Chemicals

This appendix provides protocols for some commonly used disposal and decontamination procedures along with analytical techniques that are used to verify that reagents have been decontaminated. Some of the specific reagents covered are diaminobenzidine, ethidium bromide, cyanogen bromide and chloromethylsilane. With modification, these assays may also be used to determine the concentration of a particular chemical. Precautions are also detailed for routine handling of viable pathogenic microorganisms, as well as all human-derived materials, because they may harbor dangerous pathogens such as human immunodeficiency virus (HIV), hepatitis B virus (HBV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), and a host of bacterial pathogens.

Microstructure and Compactive Instabilities of a Stabilized Residue

Cement stabilization of metallurgical residues is a frequently implemented option to reduce the associated environmental risks and thus simplify residue disposal procedures. As chemical stabilization is the first and main purpose of the process, physical testing of these stabilized residues is usually kept simple with unconfined compressive strength, permeability, and durability as the most frequently employed control tests. These tests are, however, unable to deliver a true image of the potentially complex mechanical behavior after stabilization of some important residues. One example is treated sludge. Stabilizing agents and fine residues are usually mixed at high water contents, resulting in a very porous microstructure, with fragile bonds. Under loading, rapid destructuration and compaction is possible and this process may be prone to material instabilities. These phenomena are experimentally and theoretically illustrated herein. The experimental illustrations are brought from a microstructural study and undrained triaxial campaign on a stabilized jarosite. The theoretical explanations are obtained from an elasto-plastic model previously employed for soft rocks.

ESTUDO DA DISPOSIÇÃO FINAL DE RESÍDUOS SÓLIDOS DE CURTUME COMO FONTE DE ALTERAÇÃO DA QUALIDADE DAS ÁGUAS SUBTERRÂNEAS

This work aim to study the impacts caused by the disposal of residues from two tanneries localized in the municipalities of Cuiabá and Várzea Grande in Mato Grosso State, particularly on groundwater. In one of the tanneries (tannery 1), the final residue disposal was done over an impermeable blanket inside a trench covered with amianthus tiles while in the other (tannery 2) the residues were disposed directly on the soil covered with the impermeable blanket. To achieve this objective, physical chemical and chemical properties which could indicate alteration of groundwater quality in the areas of final disposal of tannery residues were determined. Groundwater samples were collected in monitoring wells built in those areas. The analysis of the physical chemical and chemical variables allowed the following conclusions: i) the residues disposal in tannery 1 contributed to increase chromium concentrations, pH; electrical conductivity and also total dissolved solids; ii) the residues disposal in tannery 2, contributed to increase the concentrations of chloride, electrical conductivity and as a consequence total dissolved solids. Although the two tanneries are at work for different times (tannery 1 from 2000 and tannery 2 from 1986) using different residues disposal procedures, no significant difference were observed in the alteration of groundwater quality in the two sites.

Safe Use of Hazardous Chemicals

This appendix provides protocols for some commonly used disposal and decontamination procedures along with analytical techniques that are used to verify that reagents have been decontaminated. Some of the specific reagents covered are diaminobenzidine, ethidium bromide, cyanogen bromide and chloromethylsilane. With modification, these assays may also be used to determine the concentration of a particular chemical.

Laboratory waste management: evaluation of the disposal procedures routinely adopted by three Brazilian public institutions

Academic, analytical and research laboratories generate small amounts of a large variety of wastes which makes their management difficult. Proper disposal procedures must to be adopted to fulfill good laboratory practices and meet legal guidelines. A correct disposal procedure should include knowledge of the waste management steps and toxicological data for each of the substances handled, as well as adequate waste management training. Therefore, waste management should be mandatory in routine institutional criteria and be based on administrative decisions, budget compatibility and a consistent educational program.

A Modification to the Adams‐Evans Soil Buffer Determination Solution

Many soil analysis labs routinely determine lime requirement of acidic soils using different buffer solutions for optimum plant growth. The Adams‐Evans lime determination solution was introduced more than 40 years ago and has been used by many soil analysis labs. Even though many buffer solutions have been developed since then, very little attention has been paid to address the toxic nature of chemicals involved in buffer solutions. The most commonly used buffer solutions, such as the Adams-Evans, Shoemaker‐McLean‐Pratt (SMP), Woodruff, and others, contain p‐nitrophenol, which is toxic to humans and the environment. Use of p‐nitrophenol requires prescribed containment and disposal procedures, that creates extra burden on soil analysis labs that provide their invaluable service at low cost. Replacing p‐nitrophenol with monobasic potassium phosphate (KH2PO4), which has similar buffering capacity but with no known toxicity, is beneficial to soil testing labs and the environment. The original Adams‐Evans buffer solution was compared with the modified Adams‐Evans buffer solution with soils of different pH, cation exchange capacity and lime requirement. The linear regression between the buffer pH values and lime recommendations made by Adams‐Evans and the modified Adams‐Evans solutions were highly significant. Thus, the modified Adams‐Evans buffer solution can be used without loss of established recommendation criteria as the original buffer solution.

Stabilization/solidification of galvanic sludges by asphalt emulsions

A combination of two-aqueous asphalt emulsions was proposed for stabilization/solidification treatment of galvanic sludges prior to landfilling. The presented procedure comprises mixing the galvanic sludge with a slow setting nonionic asphalt emulsion and subsequently forming a secondary asphalt barrier by means of a rapid setting anionic asphalt emulsion. The method was tested on four samples of galvanic sludge from various galvanizing plants, with various water and pollutant contents. Stabilization efficiency was assessed by water-leaching test, TCLP test and by determining ecotoxicity of leachates. Leachate parameters exhibited very low values and favorable results of ecotoxicological tests indicate high efficiency of the developed procedure for galvanic sludge disposal.

Feasibility of Stormwater Treatment by Conventional and Lamellar Settling With and Without Polymeric Flocculant Addition

Abstract Stormwater treatment by lamellar and conventional clarification, with and without flocculant addition, was investigated in Toronto, Ontario, using a pilot-scale rectangular clarifier vessel with removable lamellar plates. During the 2001 to 2003 field seasons, 76 stormwater runoff events were characterized with respect to flow and quality, and further investigated for stormwater treatment. Most stormwater constituent concentrations at this site exceeded those for the U.S. NURP median urban site. A cationic polymeric flocculant dosed at 4 mg/L, with lamellar clarification, provided the best results with a total suspended solids (TSS) removal of 83% at total vessel surface loads up to 36 m/h. The clarification processes produced a concentrated sludge, which was strongly polluted by heavy metals and would require special disposal procedures.

Assessing the efficacy of dredged materials from lake panasoffkee, florida: Implication to environment and agriculture part 1: Soil and environmental quality aspect

Assessing the efficacy of dredged materials from lake panasoffkee, florida: Implication to environment and agriculture part 1: Soil and environmental quality aspect

Environmental Concerns: Catastrophic Events and Insurance. II. Applications of Hydrocarbon Risking Procedures to other Fields

With ongoing reduction of engagement of public authorities in infrastructure development, private companies have to consider their responsibility in the case of catastrophic events, i.e. they must be aware of, and be able to calculate and finance, the kinds of risks that formerly were handled by the public authorities. This paper discusses the environmental costs and insurance needed in the cases of catastrophic failure of a project due either to natural causes as the project is being developed or after it is underway in an operating mode. Anthropogenic catastrophes also can occur and these, too, are considered from the viewpoint of insurance cover needed. A third sort of catastrophe can occur if regulations are changed during development of a project or after the project is in operation. In all cases a corporation involved in such projects needs to figure out how much insurance to take out against the possibility of a catastrophe and also the premium it should pay. Using examples from the tunnel construction theater of operations, from oil exploration and field development, and from regulatory changes that can influence waste disposal procedures, this paper shows how general procedures, developed to accommodate for such risk in operating systems in the hydrocarbon area, can be used almost as is in other fields and they also provide procedures for correctly allowing for catastrophic events to be included in assessing probable profitability and associated insurance needs at the same time. Numerical illustrations are given to illuminate the points being made as clearly as possible. The basic point made is that procedures developed for hydrocarbon risk assessment can be equally used, almost without change, in many other areas where risk is a concern.

Electrochemical or UV-photochemical oxidation of industrial wastes containing polar aromatic sulphonates.

BACKGROUND AND INTENTION: Aromatic sulphonates other than surfactants and their hydroxy and amino-derivatives are important intermediates for the production of azo dyes. Their production on a large scale can be detrimental for the environment, if the by-products of their synthesis are not disposed of appropriately. An industrial waste, the organic components of which were mainly amino and hydroxy-substituted aromatic sulphonates, seriously endangers the environment close to an dismissed Italian industrial site. Inorganic sulphates and chlorides contained in the waste seriously hinder its disposal by incineration, since they corrode furnace walls. In this work, preliminary exploration of aqueous-phase electrochemically and photochemically induced oxidation techniques have been performed as possible alternatives to incineration. Electrochemically-induced oxidation was experimented on individual aromatic sulphonates and on an industrial waste by electrolysing them between smooth platinum electrodes at low temperature (5 degrees C) and high current densities (0.4 A/cm2) with aqueous 0.5 M NaHSO4 electrolyte. Photochemically-induced oxidation was performed by irradiating individual aromatic sulphonates or industrial waste with a 500 W mercury lamp in the presence of sodium peroxydisulphate. After 200 min electrodegradation, 90% of the original compounds disappeared, while 50% Total Organic Carbon (TOC) of an industrial waste was removed from solution after 10 hours. After 180 min UV-photodegradation, 90% of two test aromatic sulphonates disappeared, while 65% of TOC of industrial waste was removed after 5 hours. Two methods, electrochemical and UV-persulphate oxidation of an industrial waste, were used in order to propose a disposal procedure alternative to incineration. Electrodegradation with smooth Pt anode in 0.5 M NaHSO4 at 5 degrees C halved TOC concentration within 10 hours, while persulphate-assisted UV-photochemical oxidation with a 500 W high pressure Hg lamp abated two-thirds of TOC concentration after 5 hours. Energetic consumption of electrodegradation was 0.33 kWh/g TOC, while that of photooxidation was larger than 2 kWh/g TOC. Although both techniques can be considered efficient from a purely chemical point of view, since both are capable of wet-oxidising the aromatic sulphonates and the industrial waste, electrodegradation seems more promising than a photochemical degradation if economical considerations are also taken into account. Considering also that neither cell design nor catalyst were optimised in this preliminary study, the energy yield of electrodegradation seems likely to be largely improved.

Hospital waste operational procedures: A case study in Brazil

This study analysed the hospital waste management practices and their implications to public health in the city of Belo Horizonte, south eastern Brazil. Belo Horizonte is a regional capital city located 300 miles from the famous city of Rio de Janeiro, Brazil. It is only 100 years old and is the first city planned in Brazil. It was originally planned for 300,000 people but, today, it is home to more than 2 million people. This study assessed the operational procedures at five hospitals (170 to 450 beds) with different medical specialties in order to analyse their major waste problems. This study also gathered data on different types of treatment and disposal procedures used by waste generators, which enabled an estimate on the amount of on-site and off-site waste generated.

Risk of transmission of hepatitis B virus through childhood immunization in northwestern China

Transmission of bloodborne pathogens by means of unsafe injection practices is a significant public health problem in developing countries. Although the overall proportion for immunization is low among injections, unsafe immunization practices affect mostly infants, a population with an increased likelihood of becoming hepatitis B virus carriers. This study estimated the prevalence of unsafe injection among vaccinators working at the peripheral level in northwestern China and the risk of HBV infections among infant vaccinees, and analyzed factors contributing to the most prevalent unsafe practice: the reuse of a non-sterilized reusable syringe among infants. A knowledge–attitude–practice survey was conducted in which 180 peripheral vaccinators selected by multi-stage cluster sampling in each of four provinces and one autonomous region completed a self-administered questionnaire. The lack of observational data for assessing the validity of the self-reported practices made the study prone to systematic respondent bias that may have skewed the results towards underestimation of unsafe practices. The minimum estimate of the percentage of peripheral vaccinators reusing a syringe and/or needle without sterilization between infants was 7.2–55.0%, whereas the percentage of those disposing of used disposable syringes and needles inappropriately was 8.9–23.3% by province. According to a model-based estimate, the annual number of HBV infections among 100,000 fully immunized children due to unsafe immunization injection was at least 135–3120. An insufficient supply of syringes and the attitude to justify reuse were significantly associated with the unsafe reuse of a reusable syringe in most part of the area studied. Introduction of auto-disable syringes may contribute to curb the unsafe practices, but the development of safe collection and disposal procedures for used syringes and needles is prerequisite. Sufficient supply of equipment as well as training, supervision, and monitoring targeting specifically on the risk behaviors and concerned attitudes are essential for behavior changes among the vaccinators.

The importance of bovine neosporosis for abortion in Switzerland

The protozoan parasite Neospora caninum is one of the most important infectious abortion causes in cattle worldwide. In a Swiss case-control-study we investigated 113 abortion problem farms and 113 control farms. It was possible to detect N. caninum in 21% of 242 investigated aborted fetuses by PCR upon brain samples. Eighty-four % of mothers aborting N. caninum positive fetuses were serologically positive for this parasite. The seroprevalence for N. caninum of all aborting mothers was 44%. Within a period of 3 to 12 months 4,505 cattle from the participating farms were investigated serologically at two different time points. Strong fluctuations of the specific antibody concentration could be observed, resulting in a conversion to seronegativity in the second blood sample in 39% of formerly seropositive animals. Eighteen months after the end of the study, 42 case- and 42 controlfarms were questioned about their present abortion-status. Analysis of the questionnaire revealed that 80% of the former abortion problem farms observed an improvement of the situation. However, in 43% of those farms no preventive measures had been taken and no significant differences in hygiene, forage and animal turnover could be observed between case- and control-farms. Additionally, no significant differences were detected concerning risk factors such as the presence of farm dogs and the disposal procedure for placental and fetal material.

Debris assessment for Skybridge constellation

The Skybridge system is a worldwide ATM broadband communication system based on a 80 low Earth orbit satellite constellation. The minimization of space debris generation has been taken into account very early in the frame of this program. The objectives are, first to identify the contribution of Skybridge to the space debris generation and secondly to assess the risk due to space debris for the whole system. This paper summarizes the approach of the Skybridge program for debris assessment and mitigation. As no international regulation dealing with this subject exists, the analysis is based on the existing NASA 1740 Safety Standard. The methodology and the software presented in this document were applied to demonstrate the compliance of Skybridge with the requirements. In addition the new CNES standard was used to derive additional requirements. The first point deals with the production of space debris in the various mission phases: this concerns debris released during launch, constellation deployment and mission operations. Besides these normal operations, space debris can also be generated through material ageing or in case of accidents such as explosion due to on-board stored energy or collision with other orbiting objects. In the second part the collision risk is analyzed: the probability of collision with the large cataloged objects is determined. Concerning the smaller debris, the flux models give the probability of impact per surface unit: the analysis identifies components most vulnerable to debris impact together with their shielding and gives the associated probability of failure taking into account the architecture of the satellite. The problem of the post-mission disposal procedure is then discussed in the third part.

Laboratory safety.

This appendix provides protocols for some commonly used disposal and decontamination procedures along with analytical techniques that are used to verify that reagents have been decontaminated. Some of the specific reagents covered are diaminobenzidine, ethidium bromide, cyanogen bromide and chloromethylsilane. With modification, these assays may also be used to determine the concentration of a particular chemical. Precautions are also detailed for routine handling of viable pathogenic microorganisms, as well as all human-derived materials, because they may harbor dangerous pathogens such as human immunodeficiency virus (HIV), hepatitis B virus (HBV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), and a host of bacterial pathogens.

The basis of a policy for minimizing and recycling food waste

Abstract The life cycle of basic food items was studied in order to discover the reasons for low landfill diversion rates of this material. Management failures at key points of the cycle were identified. Subjects of study were commercialization procedures of fruit and vegetables before consumption, consumption proper and after-consumption disposal procedures for food scraps in the Brazilian context. Before consumption, the rate of lost fruit and vegetables stood at 16 wt.% of the total quantity commercialized. During consumption by residents, the waste rate of food amounted to 9 wt.% of all collected household garbage. In the after-consumption sector of the cycle, biodegradables represented 72 wt.% of all household garbage collected by official means in a typical Brazilian town. The numbers produced clearly identified landfill diversion of biodegradables as a management problem. The authors experimented with original proactive administrative procedures designed to set landfill diversion targets. The occurrence of wasted fruit and vegetables at the wholesaler and retailer levels was identified. Remedies were proposed and tested to reduce this waste by at least 50%. In the after-consumption sector, the notion of divided garbage collection was developed and applied to test communities. It was shown that biodegradables may be collected separately from the rest of household waste. This resulted in a diversion potential of 100% for biodegradables alone and 77 wt.% for all collected household waste. The study produced a formal policy proposal to municipal administrations to avoid the need for tipping of biodegradable material.

Evaluation of procedural modifications to reduce glutaraldehyde vapors during the disinfection of endoscopes using three sampling methods

Glutaraldehyde is the preferred disinfectant for fiberoptic endoscopes. A number of studies have reported adverse health effects in workers exposed to glutaraldehyde vapors. High exposures can occur during the pouring and disposal of glutaraldehyde solutions. This study has tested the effectiveness of three procedural modifications designed to reduce exposures during these activities. These procedures were: (1) the use of a splash-resistant safety nozzle during the pouring of glutaraldehyde solutions, (2) the use of neutralizers during the disposal of glutaraldehyde solutions, and (3) the pouring of 14-day versus 28-day glutaraldehyde solutions. This study also evaluated three sampling methods to monitor glutaraldehyde vapors. The three methods evaluated were: (1) the OSHA method 64 using filter cassettes impregnated with 2,4-dinitrophenylhydrazine (DNPH); (2) DNPH-coated passive diffusion badges; and (3) a direct reading glutaraldehyde meter. Results showed that when the safety nozzle was not used during disinfection procedures, geometric means for all sampling methods were above the ACGIH TLV of 0.05 ppm (filter cassettes=0.105 ppm; passive badges=0.191 ppm; meter=0.082 ppm). Using the safety nozzle during the pour resulted in significant reductions in glutaraldehyde vapor concentrations (filter cassettes=0.014 ppm; passive badges=0.027 ppm; meter=0.021 ppm). Disposal of non-neutralized glutaraldehyde solutions resulted in peak vapor concentrations of up to 0.10 ppm. Neutralization prior to disposal reduced glutaraldehyde vapor concentrations to less than 0.01 ppm. Conclusive differences were not found when the pouring of the 14-day glutaraldehyde solution was compared to the pouring of the 28-day glutaraldehyde solution. Both solution pours resulted in vapor concentration means exceeding the TLV. Comparison of sampling methods showed no statistically significant differences between each method pair or when all methods were compared simultaneously. For the detection of glutaraldehyde vapors, the meter was as sensitive and as accurate as the filter cassettes. In conclusion, employees can significantly reduce exposures to glutaraldehyde vapors by using these modified pouring and disposal procedures, and the meter examined in this study provides an optimal method to measure glutaraldehyde vapors.

Towards waste minimisation in WWTP: activated carbon from biological sludge and its application in liquid phase adsorption

AbstractSurplus sludge produced during the biological treatment of wastewater requires costly disposal procedures. With increasing environmental and legislative constraints, increasing sludge production and more limited disposal options, new recycling alternatives have to be found. The possibility of obtaining activated carbons from surplus biological sludge by chemical activation with H2SO4 has been investigated. Operational parameters such as the amount of H2SO4 added, the temperature, and activation time were modified to ascertain their influence on the quality of the activated carbon obtained. The quality of the sludge‐based activated carbons was evaluated by established characterisation parameters for adsorption from solution such as phenol value, iodine number, methylene blue number and tannin value and compared with commercial activated carbons. Activation at 700 °C for 30 min in the presence of 0.5 cm3 H2SO4 g−1 dry solids in the sludge led to an activated carbon with a good capacity for iodine and tannic acid. The sludge‐derived activated carbon obtained is mesoporous in nature with a high presence of large macropores. Weak and moderate acidic surface functional groups were detected on the surface, which impart a hydrophilic nature to the solid. When compared with a commercial activated carbon, the sludge‐derived activated carbon performed better when removing dyes with a high presence of anionic solubilising groups and heavy metals. The results indicate that COD adsorption from a biologically‐treated effluent may also be an area for application.© 2002 Society of Chemical Industry

Radiological impact on the workers, members of the public, and environment from the partial decommissioning of Pakistan Research Reactor-I and its associated radioactive residues.

The Pakistan Research Reactor-I (PARR-I) is a swimming pool type research reactor originally designed and built for a thermal power of 5 MW using High Enriched Uranium (HEU) fuel. In 1990-1991 the reactor was redesigned, partially decommissioned and recommissioned to operate with Low Enriched Uranium (LEU) fuel at a thermal power of 10 MW. An essential requirement, construction and commissioning of a wet spent fuel storage bay and fabrication of an irradiated fuel transfer cask were completed before actual dismantling of the reactor core. During the partial decommissioning operations, radioactive waste generated included 600 m3 low-level liquid radioactive waste and 14 m3 of solid radioactive waste with an average specific activity of 4.52 Bq ml(-1) and 2.22 kBq g(-1), respectively. External radiation doses of the workers were determined using TLD (NG 6,7) and direct reading dosimeters. The maximum individual external radiation dose received by any worker during this practice was 5 mSv, which was 25% of the annual dose limit of 20 mSv. Detection and measurement of internal contamination was carried out using bioassay techniques. During the whole operation, not a single case of internal contamination was detected. The ambient radiation levels around waste seepage pits are periodically monitored using TLD (G-2 cards) and G. M. radiation survey meters. Underground migration of radioactivity is checked by analyzing seepage water samples taken from boreholes that have been dug at different locations in the vicinity of the radioactive residues. The monitoring around disposal sites containing radioactive residues has been continued during the last 9 y and will be continued in the future. So far, no rise in the environmental gamma radiation dose level and migration of underground radionuclides has been found in the vicinity of these disposal sites. Working personal during the decommissioning of PARR-I have been found to be radiologically safe. Adherence to the ALARA principle, sound decommissioning and proper radioactive waste disposal procedures helped to protect the working personnel, members of the public, and the environment from the harmful effects of the ionizing radiations present due to the partial decommissioning of the research reactor and its radioactive residues. Experience gained during this work, along with the current international procedures, will be helpful for full restoration of the environment from radioactive residues likely to be generated in the future from any other practices in Pakistan.