Assembling and Using a Simple, Low-Cost, Vacuum Filtration Apparatus That Operates without Electricity or Running Water

Abstract

A simple, energy-saving vacuum filtration apparatus was successfully devised and applied in both a teaching laboratory for chemistry experiments undertaken by students and a scientific research laboratory. Compared with a conventional vacuum filtration apparatus, such as a mechanical vacuum pump, water-circulating vacuum pump, or water aspirator, the novel vacuum filtration apparatus exhibits many obvious advantages: portability, no need of a laboratory setting, energy-saving, costeffectiveness, facilitating manipulation anytime and anywhere, and a very good filtration effect in the absence of electricity and running water. An air control valve plays a key part in this system. It can hold back outside air to decrease the pressure inside the suction flask by exerting a continual pull on the hand-held pump, and achieves the same filtration effect as a water-circulating vacuum pump. The vacuum filtration apparatus is suitable for different volumes and various liquid−solid mixtures, including organic and inorganic compounds; therefore, it has great potential for wide application.

An Inexpensive Recirculating Water Vacuum Pump for the Chemistry Laboratory

“…The one gallon pail (6) has a compact footprint and a lid ( 7) with a flat surface area that accommodates the pump and hardware. The diaphragm water pump ( 1) is bolted to the pail lid using machine screws (8), washers (9), and nuts (10)…”

“…Low-cost and/or alternative apparatuses for laboratory tasks requiring vacuum have been reported in JCE − and elsewhere . In this paper, we describe the design of a 3D-printable water aspirator pump that functions effectively in a recirculating water vacuum pump or attached to a laboratory faucet, the construction of a recirculating water vacuum pump, and the performance testing of the recirculating water vacuum pump and (faucet) water aspirator pump against commercial models.…”

Low-Cost Equipment for Photochemical Reactions

“…Most of them are designed for working at the 200–400 mL reaction volume scale. − However, photoreactions in smaller volumes with smaller amounts of material are sufficient for teaching experiments. Such smaller devices are commercially available but expensive, e.g., the micro photochemical reaction assembly from Aldrich. , In science education, microscale experiments , and low-cost experimental techniques − are preferred. One has to distinguish between immersion well reactors with light sources inside the reaction mixture and setups with external light sources.…”

Setup for Semimicro Pressure Filtration

“…However, filtration can become a significantly annoying task with low-boiling-point solvents; with hard-to-get, expensive, or air-sensitive substances; or with slurries that emit toxic fumes. As a consequence, extensive literature exists on semimicro filtration procedures − that address one or more of the different problematic details of the process.…”

“…The procedure described in most of the listed references is “vacuum filtration”, ,,− ,,,, which accelerates solid–liquid separation by reducing the pressure on the filtrate side. Although there is mention in the literature of unwanted evaporation of the filtrate, crystallization in the stem of the funnel, and clogging of the filter support or of the filter itself, thus resulting in the need to abort the procedure when handling appreciably soluble materials or volatile solvents, , we could not find an analysis of the causes of these troubles, despite the fact that such causes can be satisfactorily analyzed by following the values of the pressure from its highest (atmospheric) value (i.e., that at the slurry location, P s ) to its lowest value (i.e., that at the filtrate site, P f ).…”