Cyanide có trong nước thải, thành phố trực thuộc Trung ương có nguồn gốc từ các nguồn công nghiệp. Cyanide cũng có thể được đầu vào hoặc tạo ra trong quá trình xử lý nước thải, thành phố trực thuộc Trung ương, chẳng hạn như bằng việc giới thiệu chất rắn sinh học đốt cháy chà sàn nước hoặc trong điều kiện oxy hóa của quá trình khử trùng. Cyanide là hợp chất thường được sử dụng trong một số ngành công nghiệp, và có mặt trong quá trình liên kết nước thải. Các ngành công nghiệp tạo ra một lượng lớn nước thải. | 25 Management of Cyanide in Municipal Wastewaters David A. Dzombak Anping Zheng Michael C. Kavanaugh Todd L. Anderson Rula A. Deeb and George M. Wong-Chong CONTENTS Sources of Cyanide in Municipal Wastewater Treatment Plant Influent . 502 Fate of Cyanide in Municipal Wastewater Treatment. 504 Generation of Cyanide in Municipal Wastewater Treatment. 507 In-Process Cyanide Generation. 507 Cyanide in Scrubber Waters from On-Site Biosolids Incineration . 509 Management Strategies for Low-Level Cyanide in Discharges from POTWs. 510 Reduction of Cyanide or Cyanide Precursors. 511 Request a Site-Specific Discharge Permit. 511 Change Point of Compliance. 512 In-Plant Modification of Oxidation Processes. 512 Alternative Analytical Methods for Compliance . 512 Summary and Conclusions . 512 References . 513 Cyanide present in municipal sewage is derived from industrial sources. Cyanide can also be input to or generated within municipal wastewater treatment processes such as by the introduction of biosolids incineration scrubber water or in the oxidizing conditions of the disinfection process. Cyanide compounds are commonly used in a number of industries and are present in associated process wastewaters. Industries that generate large quantities of cyanide-bearing wastewaters include electroplating and metal finishing chemical production steel production and petroleum refining see Chapters 4 and 26 . As cyanide can be toxic to the microorganisms used in biological treatment processes if present at sufficiently high concentrations and because of concern about potential for HCN gas releases in sewers many industrial generators of cyanide-bearing wastewater are required to pretreat their wastewater prior to discharge to publicly-owned treatment works POTWs for example iron and steel manufacturers 1 . Thus concentrations of cyanide in influent to POTWs are generally low that is nondetectable to 500 M-g l .
