The Problem: Sewage treatment is the process of removing contaminants from wastewater, primarily from household sewage. It includes physical, chemical, and biological processes to remove these contaminants and produce environmentally safe treated wastewater (or treated effluent). A by-product of sewage treatment is usually a semi-solid waste or slurry, called sewage sludge, that has to ...
In 2014, 25% of the sludge produced at Swedish municipal wastewater treatment plants was applied to agricultural land. Even though the Swedish heavy metal limits for sludge to be used in agriculture are amongst the most stringent in the EU, more stringent heavy metal limits are proposed. Most sludge applied to agricultural land is recycled within a certification system, Revaq. Revaq has ...
This paper presents a real-time optimal control scheme based on a total cost index (TCI) by using the so-called extremum seeking control (ESC). The ESC searches the minimum value of a given performance index where the TCI consisting of the operational cost and the effluent quality cost is used as the index. An improved ESC is proposed where a transformed TCI by monotonically increasing ...
This paper studied denitrifying phosphorus removal of a novel two-line biological nutrient removal process treating low strength domestic wastewater under different sludge recycling ratios. Mass balance of intracellular compounds including polyhydroxyvalerate, polyhydroxybutyrate and glycogen was investigated together with total nitrogen (TN) and total phosphorus (TP). Results showed that ...
This study focussed on the fate of cyanobacteria cells and associated metabolites during the sludge management processes that follow the conventional drinking water treatment train. The topic is of importance, as the release of metabolites during sludge treatment may pose a risk to water quality if supernatant is recycled to the head of the plant. The study of the kinetics of cell damage and ...
Sludge treatment reed bed (STRB) systems have been used for dewatering and mineralisation of sludge in Europe since 1988. STRB systems provide substantial environmental, economic, and operational benefits compared to mechanical sludge dewatering solutions such as belt presses and centrifuges. They require less energy, no chemicals, reduce the sludge volume and produce bio solids with dry solid ...
The study was undertaken in order to recover the metal resources from acid mine drainage (AMD). A 300 m3/d continuous system was designed and fractional precipitation technology employed for the main metals Fe, Cu, Zn, and Mn recovery. The system was operated for six months using actual AMD in situ. The chemicals' input and also the retention time was optimized. Furthermore, the ...
Wastewater treatment technologies requiring large areas may be less feasible in urbanizing regions of developing countries. Therefore, a new technology, named photo-activated sludge (PAS), was investigated to combine the advantages of regular activated sludge systems with those of algae ponds for the removal of ammonium. The PAS consisted of a mixed photo-bioreactor, continuously fed with BG-11 ...
The effect on the environment of the establishment and operation of a sludge treatment reed bed system (STRB) is quite limited compared to mechanical sludge dewatering, with its accompanying use of energy and chemicals. The assessment presented here of the investment, operation and maintenance costs of a typical STRB, and of the related environmental impact, is based on the experiences gained ...
Abstract In Germany, nowadays, more than 97% of inhabitants and industry are connected to modern wastewater and sludge treatment systems. Long-term experience exists in Ger-many especially with sludge digestion. These experiences will be presented and a spe-cial focus will be on technologies for sludge pre-treatment such as e.g. thermal hydrolysis or technical solutions to recycle the ...
The U.S. Environmental Protection Agency (EPA) recently released its preliminary 2014 Effluent (liquid waste or sewage discharged into a river or sea) Guidelines Program, which outlined more regulations for wastewater from those within the metal finishing industry. A filter press has been a long-trusted solution for treating metal waste, even for those applications that are difficult to dewater. ...
Adjusting the specification according to the dewatering target. This factory recycles glass and processes them into small pieces which can be used for making glass bottles. Nevertheless, the pieces of glass need to be washed before having been shipped to another factory where the final product will be made and this cleaning water needs to be treated somehow. They had been using a belt ...
Batch experiments were conducted to determine the effect of oxidation reduction potential (ORP) on sludge reduction in a bypass micro-aerobic sludge reduction system. The system was composed of a modified oxic–settling–anaerobic process with a sludge holding tank in the sludge recycle loop. The ORPs in the micro-aerobic tanks were set at approximately +350, −90, ...
A combination of rising prices for resources and the improvement in technology make treatment of mill scale and grinding swarf an extremely environmentally friendly and economical solution. The first VacuDry® plant for the recovery of oil solvents and metals from sludges began operating in autumn 2012. Our client is a medium-sized company operating in the field of waste recycling and ...
The recycling of anthropogenic nutrients derived from the wastewater management systems is often characterized by a complex and uncertain scenario, due not only to the nature of the process but also to the involvement of different stakeholder groups. Over the past 10 years in Switzerland, policies regarding the use of sewage sludge as fertilizer have gradually shifted to a ban on use in ...
Application Rare Earth Metals Recovery Company, which is located in Albany, Oregon, recovers rare earth metals (zirconium, hafnium and titanium) via various proprietary chemical processes. Wastewater Description The wastewater consists of methyl-isobutyl-ketone (MIBK) Waste Disposal Goals The company’s waste disposal goal was ...
Overstone Country Park is situated in 160 acres of beautiful Northamptonshire country-side. The park has the River Nene on its borders. Tourists, campers and locals use the extensive natural facilities for fishing, golfing and recreational pursuits. A development of private houses for seventy five people on the private Overstone Park had been threatened with fines and possible prosecution by the ...