Answer: The proper disposal method for the filtrates isolated from the crude product isolation step depends on the nature and composition of the filtrates. Generally, there are three main routes for disposing of laboratory waste: (1) into the atmosphere, either through evaporation or through the volatile effluent from incineration; (2) into rivers and oceans via the sewer system and wastewater treatment facilities; and (3) into landfills.
Before disposing of any filtrates, you should first characterize the waste to determine if it is hazardous or non-hazardous, and if it is regulated or nonregulated. Hazardous waste is defined as any waste that exhibits one or more of the following characteristics: ignitability, corrosivity, reactivity, or toxicity. Regulated waste is any waste that is listed by the Environmental Protection Agency (EPA) or by state or local authorities as requiring special handling and disposal.