Discharge safe disposal

Acid leak from chlorine-drying system Severe burns to personnel due to sulphuric acid (fresh and spent acid) Full covers on acid lines and pump discharge safe disposal of spent acid necessary Safety showers, eyewash fountains in working areas, use ptasonal safety devices... 

M. Kneale, The Safe Disposal of Relief Discharges, Selection Use of Pressure Relief Systems for Process Plants, Institution of Chemical Engineers North Western Branch, Manchester. UK, 1989, Paper 7. 

However, because both acids and bases are used in cleaning, it may be possible to store these chemicals in a stirred buffer tank to allow the solution to neutralise. This solution may then may be slowly added to the concentrate waste to dilute it and allow for a safe disposal (Mauguin and Corsin 2005). Note that the volume of this discharge is much lower than both the concentrate and filter backwash discharges. 

The production process evolves close to 1 t of gaseous sulfur dioxide and 0.3 t of water-soluble sodium sulfoxides for every tonne of pigment produced. These must be disposed of in an environmentally acceptable manner. If the soluble salts are fully oxidized, they can be discharged safely into tidal waters. Future legislation in all producing countries may require removal of sulfur dioxide from the effluent gases before discharge to the atmosphere. 

The process of adsorption on carbon is applicable to wastewaters and polluted air. Treated waters may be suitable for reuse in industrial processes and can be discharged safely to the sewer system if removal efficiencies are high enough. Hazardous constituents of no commercial value that are removed may be disposed in burial sites after they have been stabilized. The high capacity of activated carbon for many compounds is attributable to the large surface area of the carbon (500-1500 m2 g-1). 

The RO process was implemented at the Institute of Atomic Energy, Swierk. The wastes collected there, from all users of nuclear materials in Poland, have to be processed before safe disposal. Until 1990 the wastes were treated by chemical methods that sometimes did not ensure sufficient decontamination. To reach the discharge standards the system of radioactive waste treatment was modernized. A new evaporator integrated with membrane installation replaced old technology based on chemical precipitation with sorption on inorganic sorbents. Two installations, EV and 3RO, can operate simultaneously or separately. The membrane plant is applied for initial concentration of the waste before the evaporator. It may be also used for final cleaning of the distillate, depending on actual needs. The need for additional distillate purification is necessitated due to entrainment of radionuclides with droplets or with the volatile radioactive compounds, which are carried over. 

Burgoyne, J.H., 1987, Review paper safe disposal of relief discharges. Hazards from Pressure, Symposium Series No. 102. 201-214 (IChemE. Rugby. UK). 

The gas disposal assembly conveys the excess gases to a point where they can be discharged safely into the atmosphere. Several methods in use include a nonrecirculating or recirculating ventilation system, a central vacuum system, a dedicated waste gas exhaust system, or a passive duct system. 

Industrial and municipal wastewater treatment is designed to permit the safe disposal of the discharged water. The important components of the contaminants are ... 

When the discs rupture a large quantity of hydrogen, along with hot sodium and corrosive reaction products, is released. The hydrogen has to be separated and discharged safely, while the sodium and reaction products have to be trapped and retained for disposal. 

Morris, C.A. and P.H. Everall. 1972. Safe disposal of air discharged from centrifuges. Letter. J. Clin. Pathol. 25 742. 

Disposal Discharge of wastes to air, water or land in properly controlled, or safe, ways such that compliance is achieved. Secure land disposal may involve volume reduction, encapsulation, leachate containment and monitoring techniques a c j 5 j ... 

Conventional Flare System - The majority of pressure relief valve discharges which must be routed to a closed system are manifolded into a conventional blowdown drum and flare system. The blowdown drum serves to separate liquid and vapor so that the vapor portion can be safely flared, and the separated liquid is pumped to appropriate disposal facilities. The blowdown drum may be of the condensible or noncondensible type, according to the characteristics of the streams entering the system. Selection criteria, as well as the design basis for each type of blowdown drum, are detailed later in this volume. The design of flares, including seal drums and other means of flashback protection, is described later. 

The purpose of the facilities described in this chapter is to provide for safe handling of various drainage materials and emergency streams, so that they may be safely routed to the sewer, tankage, flare, or other appropriate destination. Drainage systems specified herein ensure that flammable or toxic materials may be disposed of without hazard of fire or injury when equipment is taken out of service. Also described are systems to handle process water drawoffs, cooling water, and other aqueous effluent streams which may be contaminated with hydrocarbons, and which could otherwise create hazardous conditions if they were discharged directly to the sewer. 

Disposal of Seal Water - Effluent water from water seals must be routed to safe means of disposal, considering possible hazards arising from liquid or vapor hydrocarbons or toxic materials that may be entrained or dissolved in the water. Seal water should be discharged as follows ... 

A process is described [224] in which an exothermic reaction takes place in a semi-batch reactor at elevated temperatures and under pressure. The solid and liquid raw materials are both toxic and flammable. Spontaneous ignition is possible when the reaction mass is exposed to air. Therefore, the system must be totally enclosed and confined in order to contain safely any emissions arising from the loss of reactor control, and to prevent secondary combustion reactions upon discharge of the materials to the atmosphere. Further, procedures and equipment are necessary for the safe collection and disposal of solid, liquid, and gaseous emission products. 

While the plant is in operation, but not producing water that is of the required quality, two additional discharge streams can be produced (Mauguin and Corsin 2005). This usually occurs during the startup of the plant. The first stream is the pretreated water which has not reached an acceptable quality to pass through the membrane unit. Its composition is largely similar to that of the feed, and if membrane processes are not used as pretreatment, its salinity should be the same as feed. The second stream is the permeate which has not yet reached the desired quality of the final water product. This stream will have a lower salinity than the feed, and should not contain great quantities of harmful chemicals. Both these streams should be safe for disposal in the concentrate stream. 

Finally, a means must be available for the disposal of the sample after it leaves the analyser. Direct discharge to atmosphere or to drain is possible only where it is safe to do so. In some cases this is done after suitable treatment and in others the sample is pumped back to the process. 

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