The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 11, 2012
Filed:
Jul. 25, 2008
Hongqiang Ren, Nanjing, CN;
Lili Ding, Nanjing, CN;
Tao Zhang, Nanjing, CN;
Nanjing University, , CN;
Abstract
A new method for removing ammonia nitrogen in coking wastewater is disclosed in this invention. It comprises steps as follow: introducing coking wastewater into a reaction pool into which magnesium and phosphate are added; adding sodium hydroxide to regulate the PH of the mixture around 9.0-10.5; separating the supernatant and the precipitate after proper agitation and natural precipitation; dehydrating the precipitate and then adding alkaline fly ash, water to the dehydrated precipitate and stirring the mixture; decomposing the mixture with heating and absorbing the ammonia gas thereof produced with acidic solution. In consideration of high concentration of ammonia nitrogen in coking wastewater, this invention aims at quick and efficient treatment. The concentration of ammonia nitrogen in treated water meets the highest discharge standard stipulated in [China National](GB8978-96). Meanwhile, this invention provides a new way for beneficial utilization of the alkaline fly ash as well. The chemicals adopted for wastewater precipitation in this invention can be recovered for recyclable use, which consequently cuts down the total cost of the wastewater treatment.