Field and laboratory investigation on geotechnical properties of sewage sludge disposed in a pit at Changan landfill, Chengdu, China

Occurrence and distribution of organophosphate triesters and diesters in sludge from sewage treatment plants of Beijing, China

“…It is estimated that approximately 65% of mechanical dewatered sewage sludge in China is disposed in landfill (Zhan et al, 2014). However, this management strategy represents an additional entry route for pollutants into the terrestrial environment, and then produces harmful effects on microorganisms.…”

Geotechnics of municipal sludges and residues for landfilling

“…Further, they typically exhibit very low shear strength, very high compressibility, swelling and shrinkage potentials and have very to extremely low permeability (Arulrajah et al (2011, Aydilek et al (2000), Chen et al (2014), Diliūnas et al (2010), Disfani et al (2013Disfani et al ( , 2015, Kayser et al (2011), Klein and Sarsby (2000), Koenig and Bari (2001), Lin et al (2014), Lo et al (2002), O'Kelly (2006O'Kelly ( , 2008aO'Kelly ( , 2008bO'Kelly ( , 2010O'Kelly ( , 2013aO'Kelly ( , 2014aO'Kelly ( , 2016aO'Kelly ( , 2016b, Quille (2009, 2010), Wang et al (1992), Wang and Tseng (1993), Wichmann and Riehl (1997), Zhan et al (2014), to name a few). For landfilled material, chemicals added during the water/ wastewater treatment processes tend to enhance the strength properties but reduce the level and rate of consolidation achievable on-site (O'Kelly and Quille, 2010).…”

“…Management of these increasing amounts of sludge and residue materials is a key issue. Principal disposal options for these materials are ■ indefinite storage in shallow or deep lagoons (Claydon et al, 1997;Klein and Sarsby, 2000;Lin et al 2014;Zhan et al, 2014) ■ volume reduction by mechanical and (/or) thermal means followed by landfilling, either at dedicated monofills (O'Kelly, 2004(O'Kelly, , 2005b(O'Kelly, , 2010(O'Kelly, , 2016dLin et al 2014;Wang et al, 1992;Zhan et al, 2014), dedicated deposition areas at sanitary landfills (O'Kelly, 2008a) or co-disposal with municipal solid waste (MSW) in which these residue materials are usually intermixed with MSW streams (Koenig and Kay, 1995;Koenig et al, 1996;Lo et al, 2002;Loll, 1986Loll, , 1991) ■ the preferred route of beneficial use as agricultural land fertiliser (Elliott et al, 1990), for composting to produce a humus-like product resembling soil, in forestry and soil redevelopment (e.g. mine reclamation) ■ incineration.…”

“…Difficulties in sourcing new landfill sites means that the fill height and (/or) slope angle of many existing landfills are being increased to accommodate the placement of further material (e.g. Zhan et al (2014)). The biosolids, sewage sludge and WTR materials must be adequately dewatered at the municipal works to reduce transport and landfill-disposal costs, to gain sufficient shear strength for efficient handling, placement and trafficability requirements at the landfill site and for geotechnical stability of the landfill slopes.…”

“…The ongoing biodegradation of biosolids and sewage sludge reduces the solids mass (volume) due to loss of susceptible organic matter, as reflected by the reduction in TVS and increase in specific gravity (Diliūnas et al, 2010;O'Kelly, 2005aO'Kelly, , 2006O'Kelly, , 2008bZhan et al, 2014). For instance, sewage sludge 1 slurry material was stored outdoors in drums and allowed to biodegrade naturally for a 13-year period at ambient temperatures of 5-15°C (O' Kelly, 2006Kelly, , 2008b.…”