There has been an increase in interest amongst utilities to develop solids technology concept trains that result in solids volume reduction for land application. For example, the Water Environment Research Foundation has recently initiation the OWSO “optimization” program in part to develop concepts that reduce sludge volumes for beneficial reuse or disposal. Another concept that has ...
Lehigh Cement Company has conducted preliminary and in depth testing of Class A dried biosolids (DBS) as a fuel replacement in our cement kiln at Union Bridge, Maryland. Lehigh’s parent company, Heidelberg Cement, has been using DBS in European cement kilns for several years. These programs have proved the safety and environmental soundness of this concept. Lehigh’s ongoing development of these ...
ABSTRACTThe objective of this study was to evaluate how much phosphorus and metals in sludge can be released into solution by microwave irradiation when applied to sludge prior to anaerobic digestion, and to determine the effectiveness of subsequent lime precipitation. For thickened sludge, the fraction of phosphorus in the soluble form increased to 23%~28% while for unthickened sludge, to ...
The management of biological treatment residuals is a significant activity associated with the overall management and operation of any successful wastewater treatment utility. Estimated operational and maintenance costs for residuals treatment and ultimate disposal can range from 40 to 60 percent of a typical annual treatment facility operating budget and also may represent a similar fraction of ...
Applying an electrical field for 10 min to mechanically dewatered biosolids increased dryness to 35 to 45% and reduced Escherichia coli levels to/close to detection limits. Possible reasons for the regrowth of bacterial pathogens impacted by electro-osmotic dewatering are biosolids dryness, low pH and the generation of bacterial oxidants on the anode due to high temperatures. Testing for this ...
The Borough of Mechanicsburg, located in central Pennsylvania, was experiencing challenges in finding sufficient agricultural fields to continue the beneficial use of their anaerobically digested liquid wastewater treatment plant Class B biosolids. At the time, the only alternative available was dewatering and going to landfill, which is significantly more expensive. Due to environmental ...
ABSTRACT Two large scale projects have been successfully brought on line utilising the thermal pretreatment to ensure production of a Class A biosolid product. In Reading (UK), the sludge is pasteurised prior to mesophilic anaerobic digestion while in Dublin (Ireland), the sludge is both pasteurised and hydrolysed prior to digestion. Sludge is pasteurised by holding a batch of sludge at ...
A $400 million project at the Blue Plains Advanced Wastewater Treatment Plant (AWTP) in Washington, D.C., involves building an innovative biosolids management system comprised of a thermal hydrolysis process, four 3.8-million gallon mesophilic digesters (measuring 70-ft tall by 100-ft in diameter) with fixed covers, a cogeneration system consisting of three 4.6-MW Solar Mercu ry 50 gas turbines ...
ABSTRACTGrowing concern over the cost of power and long-term availability of limited fossil fuel resources for the production of electricity have caused electrical utilities and governments to promote “green” or renewable power. Solar, wind, geothermal, biomass, biogas, and low-impact hydroelectricity are current acceptable green-power sources. Digester gas is a renewable, green energy resource ...
ABSTRACT The District of Columbia Water and Sewer Authority (DC WASA) has decided to incorporate thermal-hydrolysis pretreatment in conjunction with mesophillic anaerobic digestion as the backbone of a long-term biosolids treatment plan to produce Class A biosolids. The Authority has been lime stabilizing their raw solids from the Blue Plains Plant for many years, transporting them to the State ...
ABSTRACT Naestved central WWTP is a 5 MGD facility that was originally designed as a Bio DeNiPho plant following primary sedimentation. In 1998 the primary tank was bypassed in order to reduce organic micro-pollutants by aerobic treatment in the aeration basins. This reduced the micro-pollutants but led to a bulky undigestible sludge and foaming due to Microthrix. The Microthrix problem was ...
In 2001, the City of Phoenix, Arizona (USA) committed to the conversion of the existing high-rate anaerobic digestion process at the 8.9 m3/s 91st Avenue Wastewater Treatment Plant (WWTP) to a multi-phase process (acid/methane, mesophilic/thermophilic) to optimise existing digestion capacity and achieve Class A biosolids. The improved solids reduction is anticipated to double the ammonia load in ...
ABSTRACTAn innovative and cost-effective biosolids treatment and processing technology was developed and demonstrated at a pilot and full-scale at the Guelph Wastewater Treatment Plant in Ontario. The Lystek process involves a low but optimized application of heat, alkali, and mixing in a batch or semi-continuous system to achieve the desired physical, chemical and microbiological characteristics ...
Project Roles The Kenosha Water Utility elected to use a design-build approach due to the complex and vaired technologies associated with this project. Centrisys/CNP Technology Water & Biosolids, a dewatering/thickening equipment manufacturere and nutrient recovery/sludge optimization provider, served as teh design-build developer. Donohue & Associates served as teh engineer of ...
ABSTRACTSignificant advances have been made in the knowledge base and practical options for improving thermophilic anaerobic digestion over the past 10 to 15 years. Today, more options exist that promise to enhance the degree of stabilization achieved and finished product quality in new and retrofitted existing processes. In parallel, the body of knowledge regarding pathogen inactivation in these ...
The Moccasin Bend Wastewater Treatment Plant (WWTP) provides treatment for the City of Chattanooga, Tennessee and the surrounding region. The City has completed upgrades to the solids handling facilities to treat and dewater the primary solids and waste activated sludge (WAS) from the WWTP. This paper summarizes the process to handle the primary solids and the start-up process. Primary solids ...
The City and County of San Francisco completed a two-year pilot study of pre-treatment processes to mesophilic anaerobic digestion for improved biosolids stabilization and production of biosolids suitable for unrestricted reuse (class A biosolids). The results of this effort will help in the design of the new Solids Handling Facility (SHF) at the 11 m3/s Southeast Water Pollution Control Plant ...
Only electrokinetic system and its effect on the inactivation of pathogenic organisms in biosolids were investigated. Bench scale experiments were conducted in a series of electrokinetic (EK) reactors. Ten EK reactors were set up with different types of sewage sludge: primary, secondary (attached growth culture), secondary (activated sludge), and anaerobically digested sludge, coming from Auteuil ...
ABSTRACTBench scale experimentation was completed to assess the potential of using a short residence time pre-treatment reactor upstream of aerobic digestion to enhance the destruction of pathogens. The impact of aeration, temperature, hydraulic residence time, solids concentration, feeding frequency and mechanical shearing on the pre-treatment process was investigated. Subsequent testing ...
ABSTRACT High-solids mesophilic anaerobic digestion (HS-MAD) processes employing thermal hydrolytic pretreatment (THP) have gained much interest in recent years; primarily because they have been shown to produce Class A biosolids in accordance with EPA 503 regulations, but also because they represent an economical approach to the maximization of available anaerobic digester volume. The ...