In the development of science and technology, Water purification technology, in general, and wastewater treatment technologies, in p articular, are constantly improving with superior technologies to help treat and clean the environment. The following is a summary of wastewater treatment technologies that are widely applied today: 1 . Course treatment by simple mechanical methods Industrial wastewater, as well as domestic wastewater often contains dissolved and insoluble substances in the form of suspended particles. The suspended impurities can be solid and liquid, forming a suspension with water. To separate trash and suspended particles from wastewater, mechanical processes (interrupted or continuous) are usually used: filter through bars or mesh, settle under the effect of gravity or centrifugal force and filtration. The choice of treatment method depends on the particles, physical, and chemical properties, suspended particle concentration, wastewater flow and required cleaning level. Mechanical treatment is a method aimed at removing and separating insoluble substances and colloidal substances from wastewater. The treatment works include: • The trash rack/screen (coarse net) is operated manually • Trash rack/screen (fine filter net) operates automatically • Air conditioning tank stabilizes the flow • First phase sedimentation tank and 2nd phase sedimentation tank separate suspended sediments. Mechanical treatment can remove up to 60% of insoluble impurities and reduce pollutants capable of biodegradable (BOD) up to 20% 1.1. Filter through screens or nets This is a preliminary treatment. The purpose of the process is to remove all the objects present in the wastewater that can cause problems in the operation of the wastewater system such as clogging pumps, pipes, or canals. This is an important step in ensuring safety and creating favorable conditions for the whole system. I.2.1.1 Garbage Barrier Wastewater transported to cleaning works must first pass-through trash rack. At the trash rack, raw impurities such as trash, nylon bags, fruit peels, rags, wood, and other objects are retained to ensure stable operation of pumps and wastewater treatment facilities. This is an important step to guarantee the safety of the entire wastewater treatment system.