Middle School Laboratory Wastewater Treatment Equipment, Waste Water Treatment System, Quankun, Scheme Design, Stable Operation
Middle school laboratories are crucial for nurturing students' scientific literacy and practical skills, yet they inevitably produce various types of wastewater during experiments. This wastewater may contain harmful substances like acids, bases, heavy metals, and organic solvents. Discharging it untreated can pose severe threats to both the environment and human health. Therefore, selecting appropriate laboratory wastewater treatment equipment and establishing a scientific management system are indispensable aspects of middle school laboratory construction.
High school laboratory wastewater, although with a lower concentration compared to that from universities or research institutions, is characterized by its complex and variable composition. Common types of wastewater include:
Acid and alkali wastewater: Originating from titration experiments, pH adjustment, etc., it may corrode pipelines and disrupt the ecological balance of water bodies.
2. Heavy Metal Wastewater: Originating from chemical demonstration experiments (such as copper, lead, etc. metal salts), it is bioaccumulative.
3. Organic Wastewater: Includes solvents such as ethanol and formaldehyde, which may disrupt aquatic ecosystems.
Based on the laboratory size and characteristics of the wastewater, secondary schools can choose from different types of treatment equipment:
1. Compact Integrated Treatment Equipment: Ideal for schools with low experimental volumes, occupying only 2-3 square meters, with a daily processing capacity of 0.5-2 tons, featuring integrated neutralization, sedimentation, and filtration functions.
2. Modular Combination System: Designed for schools with numerous chemistry laboratories, it offers flexible combinations of pH adjustment modules, heavy metal collectors, and activated carbon absorption units.
3. Mobile Emergency Treatment Equipment: Used for the handling of large amounts of waste liquid in emergencies, such as the mobile treatment units produced by certain companies.
The basic requirements for the three wastes of the emission laboratory are:
1. Non-toxic, or ensure emissions are below the maximum allowable concentration set by the national or relevant authorities.
3. Corrosive substances to drainage pipes should be converted into non-corrosive substances, such as converting sulfuric acid into sodium sulfate or calcium sulfate.
4. Will not react violently with water or air or form harmful substances.
5. Free of pathogens, carcinogens, mutagens, teratogens, or to ensure discharge concentrations are below the maximum allowable concentrations set by national or relevant authorities.
6. Radioactive waste must especially comply with national emission requirements.
7. For substances with extremely active chemical properties, they should first be diluted with suitable inert materials before any corresponding treatment. Sand and soil can be used for dilution, followed by processing as described in the next section.
8. Some substances, whether in their elemental or compound form, are highly toxic. They must be recycled and not discharged, such as mercury and its salts.
Laboratory wastewater treatment equipment processing flow:
Neutralizing Unit: Add NaOH to the wastewater to adjust the pH to 8.5-9.2, causing certain ions in the wastewater to react and form precipitates, thereby removing heavy metal ions.
Coagulation Decanter: Adding a certain amount of CJI water treatment agent causes the wastewater to produce a large amount of coagulated flocs, after sedimentation, it reduces the working load of subsequent processes and improves the removal rate of COD and suspended solids.
Filtering Device: Utilizes a quartz sand filled layer to intercept and remove suspended particles and other fine substances not separated by air flotation, with timed backflushing to ensure stable filtration performance.
Activated Carbon Decolorization Unit: Utilizes the adsorption capacity of activated carbon for further deep treatment, removing color and odor from water. Ensures the effluent meets standards.
Ozone Generators (Disinfection): For E. coli, Salmonella, and other pathogens, disinfection can be achieved through the use of an ozone generator.
High School Laboratory Wastewater Treatment Equipment, Wastewater Treatment Unit, Quankun, Solution Design, Stable Operation
General Principles for Laboratory Treatment of Wastewater:
1. When waste is sufficiently scarce and safe, it can be released into the atmosphere or drainage. Aim to concentrate the waste liquid to reduce its volume and store it in a secure location in isolation; utilize methods like distillation, filtration, and adsorption to separate hazardous materials, discarding only the safe components; whether liquid or solid, anything that can be safely burned should be, but in moderate quantities, ensuring no harmful gases or residue are left during combustion. If incineration is not feasible, choose a safe site for burial, avoiding any exposure to the ground.
2. Generally, toxic gases can be removed by ventilation cabinets or ducts after being diluted by air. Large amounts of toxic gases must be burned with oxygen sufficiently or treated by adsorption before discharge.
3. Wastewater should be stored in appropriate containers and locations based on its chemical properties, using sealed containers, and should not be mixed. Label with the type, storage duration, and schedule for regular disposal.
