Advanced primary treatment: An alternative to biological secondary treatment. The city of Los Angeles hyperion treatment plant experience

Abstract

Advanced primary treatment (APT) is a process, in which chemicals are added to raw sewage to enhance total suspended solids (TSS) and biochemical oxygen demand (BOD5) removals by coagulation and flocculation. The City of Los Angeles Hyperion Treatment Plant (HTP) is the largest APT plant in the USA, servicing over 4 million people within an area of 1500 km2 and currently treating an average of 15 m3/s (350 MGD). HTP began using APT in 1986; current chemical doses to the raw sewage are 10 mg/l of FeCl3 and 0.15 mg/l of an extremely high molecular weight anionic polymer. The 1992 annual average influent TSS and BOD5 concentrations were both 330 mg/l and the APT removed an average 83% TSS and 51% BOD5 at an average surface overflow rate of 75 m/day (1900 gals/ft2,day). This paper discusses the overall performance of APT. The process is more cost effective than conventional primary treatment and its use can significantly reduce the size of the following secondary treatment process. APT is especially suitable for developing countries because of its low capital and operating costs.

Fifty-Year Review of Effluent Discharge Trends to the Southern California Bight from Large Municipal Wastewater Treatment Facilities from 1971 to 2020

“…Similarly, research such as that conducted by Zeng et al in 1997 [15] on the Point Loma Wastewater Treatment Plant's impact on organic pollutants underscores the enduring relevance of evaluating long-term historical records to track environmental changes. There have been significant strides to improve both the odor and contamination concentrations at Hyperion [16][17][18], Joint Water Pollution Control Plant [19], and Orange County Sanitation [20,21]. Given the persistent environmental impact, conducting a thorough and extended historical assessment is imperative to gauge the evolving trends and impacts of such contamination over time.…”

Coagulation–flocculation studies of tannery wastewater using cationic polymers as a replacement of metal salts

“…This fact has led to a wastewater treatment strategy of thoroughly removing the particles in the first step, for instance by coagulation, and thereafter, if necessary, using biological treatment to remove soluble biodegradable compounds. This approach not only reduces the load on the subsequent biological unit but also reduces its size and cost (Odegaard & Karlsson 1994;Shao et al 1996). In addition, it significantly improves the biological treatability of the wastewater (Orhon et al 1998).…”

Aplicação de coagulantes no afluente de reator anaeróbio de leito expandido alimentado com esgoto sanitário.

“…Recentemente, alguns trabalhos têm sido divulgados na literatura especializada nos quais são destacadas as vantagens de uma estratégia de uso de coagulantes denominada "tratamento primário quimicamente aprimorado". O sistema é recomendado por alguns pesquisadores (HARLEMAN & MURCOTT, 1999;ØDEGAARD, 1998;SHAO et al, 1996;POON & CHU, 1999, • o lodo pode ser digerido no próprio reator anaeróbio;…”