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Impact of Management Systems on Business Performance
Published in Titus De Silva, Integrating Business Management Processes, 2020
The Waste Water Treatment Division of the city of Gastonia (GWWTD) in North Carolina is responsible for treating industrial, commercial and domestic waste water in its two treatment plants. The waste water treatment process ensures that the waste water discharged to the surface meets federal requirements. Waste water is tested in its own laboratories and the GWWTD also manages biosolids and by-products from waste water treatment. Currently, the plants are subjected to the provisions of the National Pollutant Discharge Elimination System (NPDES), biosolids discharge and air quality. In February 1999, the organisation entered into a contract with the Department of Environment and Natural Resources (DENR) in North Carolina to develop and implement an EMS (Eckert, 2001, January).
Waste Management
Published in Ronald Fayer, Lihua Xiao, Cryptosporidium and Cryptosporidiosis, 2007
Sludges from clarifiers are also formed into biosolids through various biological processes. The two most common means are anaerobic and aerobic digestion. In anaerobic digestion, the sludge is typically held at 37°C (mesophilic digesters) in a liquid state for several weeks while it undergoes methanogenic digestion. Primary digesters might be followed by secondary digesters that might also have a long detention time. Aerobic digestion most typically occurs at ambient temperatures and looks like an activated sludge system maintained with a higher concentration of solids in the mixed liquor. As with anaerobic digestion, there may or may not be a secondary set of aerobic digesters. The biosolids produced by digesters may then be land-applied or treated by processes that further reduce the pathogens present within the material. In some situations, digesters can be maintained at higher temperatures, usually 50 to 55°C (thermophilic digestion); in these cases, the higher temperatures often inactivate many of the pathogens that might be present.
Solids processing and disposal
Published in Rumana Riffat, Taqsim Husnain, Fundamentals of Wastewater Treatment and Engineering, 2022
Treated wastewater sludge, commonly referred to as biosolids, is the material produced as the ultimate byproduct of the processes used to treat municipal wastewater in wastewater treatment facilities. Biosolids are nutrient-rich organic materials. They can be used for soil enrichment and can supplement commercial fertilizers. Biosolids must meet strict regulations and quality standards before being applied to land. Approximately 8–9 million tons of biosolids are produced each year by municipal wastewater treatment facilities in the US (Hong et al., 2006). In 2003, about 60% of the biosolids were reused. The beneficial reuse of biosolids is expected to increase in the near future.
Review of the effects of wastewater biosolids stabilization processes on odor emissions
Published in Critical Reviews in Environmental Science and Technology, 2019
Ruth M. Fisher, Juan Pablo Alvarez-Gaitan, Richard M. Stuetz
Traditionally, the primary outcome for wastewater treatment was for the removal of waste. In recent years, with growing concerns for the quality of our environment, the focus has shifted with the need to abide by stricter effluent emission restrictions (Oleszkiewicz & Barnard, 2006). Land application of biosolids is an attractive option for disposal due to their organic matter and nutrient value; in addition to restrictions of ocean disposal, restrictions and high costs for landfill disposal and social conflict regarding incineration (Le Blanc, Matthews, & Richard, 2008; Lu, He, & Stoffella, 2012). However, wastewater sludge needs to be properly treated and of good quality before it is acceptable for use on land and referred to as biosolids (Le Blanc et al., 2008). Application of biosolids to agricultural land can: offset fertilizer application and result in soil carbon sequestration credits, improve the soils water retention, and address unforeseen nutrient shortages (Alvarez-Gaitan, Short, Lundie, & Stuetz, 2016; Evanylo, 2006). The direct land application of biosolids is common around the world, with >60% of biosolids produced being applied to agricultural land in countries such as Australia, Czech Republic, New Zealand and Slovakia; additionally many middle-income countries are developing biosolids recycling programs (Le Blanc et al., 2008). Of the biosolids generated in Australia, 64% are applied directly to agricultural land, while a high proportion (23%) is used for land rehabilitation or first composted and used for landscaping (ANZBP, 2016).
On a voyage of recovery: a review of the UK’s resource recovery from waste infrastructure
Published in Sustainable and Resilient Infrastructure, 2019
Wastewater treatment demand is ~11 billion litres per day (DEFRA, 2012). Total investment in sewerage services 1990–2015 was £39Bn. The residue from wastewater treatment is sewage sludge. Around 75% is used in agriculture to improve soil, where it is referred to as biosolids, 15% is incinerated and a small fraction used or disposed of on other ways. The digested sludge is mixed with lime (CaO) generating heat and high pH to kill off harmful microorganisms, and then dried at >100 °C and mixed with other compostable materials (green waste, woodchip, straw) before application to farmland. Biosolids can help provide a variety of nutrients to soil including nitrogen, phosphates, potash, manganese and sulphur as well as stable organic matter essential for good soil structure.
Formulation and use of manufactured soils: A major use for organic and inorganic wastes
Published in Critical Reviews in Environmental Science and Technology, 2022
R. J. Haynes, Y.-F. Zhou, X. Weng
Biosolids are waste products of domestic wastewater treatment and consist of approximately 50% inorganic and 50% organic material. The organic components originate principally from human feces settling out during primary treatment (sedimentation) and bacterial cells settling out during secondary treatment. The organic components undergo a degree of degradation and humification particularly during the sludge stabilization phase (often anaerobic digestion). The inorganic component settles out during sedimentation and originates from sources such as local soil and sediments, broken glass and inorganic residuals of food/feces. Two major problems prevent more widespread use of biosolids in manufactured soils. These are (a) the possible presence of human pathogens and (b) the possible presence of inorganic and/or organic contaminants (Collivignarelli et al., 2019). The presence of human pathogens is greatly diminished by stabilization processes such as aerobic and anaerobic digestion, lime treatment or thermal treatment at high temperatures (e.g. 150–180 °C) (Clark & Smith, 2011; Haynes et al., 2009; Silveira et al., 2003). However, biosolids can contain contaminants such as heavy metals (e.g. Cu, Zn, Cd, Pb, Ni, Cr, As) plus a range of slowly degradable organic compounds (e.g. pharmaceuticals, natural and synthetic hormones, organotins, flame retardants and various pesticides) (Haynes et al., 2009). Thus, biosolids need to be tested for pathogens and contaminants prior to use. Public perceptions limit its use in potting media and manufactured soils used for landscaping and it is more likely to be used as a component of soils used in rehabilitation/revegetation (Sharma et al., 2017).