![Sample our Engineering & Technology journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5933/TOC-Subject-Sample-2021-Engineering-Tech.jpg"})
Abstract
As a result of increasing population, industrialization, and effluent quality, sludge production has increased worldwide. Organic micropollutants in sludge have become a more critical environmental health concern compared to heavy metals. New sludge disposal regulations limit persistent organic pollutants (POPs) in addition to conventional organic indicators like total and dissolved organic carbon. This study aims at providing a brief review on POP concentration in the sludge in different regions of the world, sludge regulations, assessment of conventional biological sludge stabilization methods according to their ability to remove POPs, and discussions on alternative sludge treatment methods. The impact of sludge treatment unit operations including conditioning, thickening, mechanical and thermal dewatering, and biological and thermal stabilization on sludge management is also discussed in the context of organics. The occurrence and removal of micropollutants such as absorbable organic halogen compounds (AOX), nonylphenol and nonylphenol ethoxylates (NPE), di-2-(ethyl-hexyl)-phthalate (DEHP), dibenzo-p-dioxins and furans (PCDD/F), polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) are also evaluated specifically for sludge treatment unit operations. A concise discussion is also included on different drying technologies suitable for drying of sludge.
Notes
a Sum of acenaphthene, phenanthrene, fluorene, fluoranthene, pyrene, benzo(b + j + k) fluoranthene, benzo(a)pyrene, benzo(g,h,i)perylene, indenol(1,2,3-c,d)pyrene.
b Sum of six congeners PCB 28, 52, 101, 138, 153, 180.
c Sum of six compounds.
d Sum of seven congeners.
e Each of six congeners PCB 28, 52, 101, 138, 153,180.
f Limit value for organic sludge for sea dumping and landfilling purposes (mg L−1).