METHOD FOR TREATING WASTE PROCESS WATER

摘要

PROBLEM TO BE SOLVED: To purify waste process water containing a large amount of organic suspended substances by removing the suspended substances simply at low costs by adding a flocculant of polyaluminum chloride into the water to adjust its pH at a specified value. SOLUTION: The flocculant adding part 20 of a laver producing apparatus adds a preset amount of polyaluminum chloride into waste filtered water discharged as waste process water from a laver making machine 14. A waste process water treating part 30 supplies the water mixed with polyaluminum chloride, produces purified treated water, and returns/supplies the treated water as mixing water and concentration adjusting water to a mixing machine 17. In this process, polyaluminum chloride is added as a flocculant into the waste process water which contains a large amount of organic suspended substances and has a buffer action in a constant range (0.03-0.21 cc to 1000 cc) to adjust pH at 6-8.