1) Definition of waste liquid:
- Drugs with expired shelf life, high-concentration solutions, standard solutions and improperly configured solutions that were discarded after the experiment.
- Waste chemical liquids removed during the use of the testing equipment.
2) Laboratory waste liquid treatment:
- Purpose of treatment: To prevent the spread of chemical contamination in the laboratory.
- Applicable scope of treatment: waste and liquid waste generated in the process of production and inspection.
- Responsibility and supervision of processing: laboratory operators implement this management system, and the supervisor in charge is responsible for supervising the implementation of this system.
3) General principles for the treatment of waste liquid in the laboratory:
- When it is proved that the concentration of the waste liquid is quite small and environmentally safe, it can be discharged into the sewer.
- If the concentration cannot be reduced, concentrate the waste liquid as much as possible to make it smaller in volume, and store it in a safe place for isolation and neutralization of acid and alkali.
- Use methods such as distillation, filtration, and adsorption to separate hazardous materials and discard only the safe parts.
- Regardless of liquid or solid, those that can be safely burned without generating harmful gases are burned, but the amount should not be too large. Do not leave harmful gases or residues when burning. If it cannot be burned, choose a safe place for landfill. Bare on the ground.
- Generally, toxic gases can be discharged through a fume hood or ventilating pipes, diluted with air, and a large amount of toxic gases must be fully combusted with oxygen or adsorbed before they can be discharged.
- The waste liquid should be stored in an airtight container and stored in a suitable container and storage location based on its chemical characteristics. The waste should not be mixed and stored. The type of waste and the storage time should be marked, and it should be treated regularly.
Four) Classification and treatment of waste liquid:
- Chemical waste
The waste liquid should be stored in a suitable container and storage location according to its chemical characteristics. It should be stored in an airtight container and cannot be mixed and stored. The label of the container must indicate the type of waste and the storage time, and it should be treated regularly. Generally, the waste liquid can be discharged after acid-base neutralization, coagulation precipitation, and sodium hypochlorite oxidation treatment. The organic solvent waste liquid should be recycled according to its nature.
- Biological Waste
Biological waste liquid should be selected according to the characteristics of its pathogenic source and physical characteristics in suitable containers and locations, and special personnel should collect them separately for disinfection and burn treatment. Nissan and Nissan are cleaned. Liquid waste can generally be chlorinated and disinfected by adding bleaching powder.
- Comprehensive waste liquid
Adjust the pH of the waste liquid to 3-4 with acid and alkali, add iron powder, stir for 30 minutes, then adjust the pH to about 9 with alkali treatment agent, continue to stir for 10 minutes, add aluminum sulfate or basic aluminum chloride coagulant, and mix Condensate sedimentation, the supernatant liquid can be directly discharged and deposited in the waste residue for disposal.
5) Specific treatment of laboratory waste liquid:
- For the waste acid, filter it with acid-resistant plastic mesh or glass fiber, then add alkali to neutralize it, adjust the PH value to 6-8 and then discharge it. A small amount of waste residue is buried in the ground.
- For the highly toxic waste liquid, corresponding measures must be taken to eliminate the toxic effects before processing.
- The condensing water used in large quantities in the laboratory can be directly discharged without pollution.
- The detergent wastewater after washing is not polluted and can be discharged into the sewer.
- After use, the acid, alkali, and salt solutions are poured into the acid and alkali salt sewage tanks, and after neutralization, they are discharged into the sewer.
- The organic solvent is recovered in the organic dirty barrel, and is recovered by distillation, rectification and other separation methods.
- Centralized treatment of heavy metal ions (including) precipitation method.
6) Matters needing attention in waste liquid treatment:
- As the composition of the waste liquid is different, there may be dangers such as toxic gas or heat generation or explosion during the treatment process. Therefore, the nature of the waste liquid must be fully understood before the treatment, and then a small amount of the required added drugs should be added separately. , You must continue to operate while observing.
- It is best to treat the waste liquid separately. If it is stored and treated together, although the treatment method will be different, in principle, the various compounds that can be treated in a unified way should be collected and treated.
- Choose containers that are not damaged and will not be corroded by waste liquid for collection. The components and content of the collected waste liquid shall be clearly labeled and stored in a safe place. Especially the toxic waste liquid should be paid more attention to.
- The waste liquid containing explosive substances such as peroxides and nitroglycerin should be handled carefully and should be disposed of as soon as possible, and should not be left untreated.
- The waste containing radioactive materials should be collected by other methods, and must be strictly in accordance with the relevant regulations, strictly prevent leakage, and be handled carefully.
7) Safety measures for waste liquid treatment:
- When handling chemical waste, you must wear splash goggles, gloves and lab coats.
- The waste liquid that releases smoke and vapor should be dumped in a fume hood.
- To prevent fumes and vapors from escaping, the mouth of the container should be tightly closed every time the waste is dumped.
- Highly active compounds, water active compounds, high-concentration oxidants or reducing agents must not be mixed with other chemical wastes.