Thomas C. Granato*, Abdul Khalique, Albert Cox and Richard I. Pietz

¹Metropolitan Water Reclamation District of Greater Chicago
Lue-Hing R&D Complex, 6001 W. Pershing Rd., Cicero, IL 60804
*To whom correspondence should be addressed.

Abstract
The Metropolitan Water Reclamation District of Greater Chicago (District) produces 190,000 dry tons of biosolids annually and uses them to fertilize turf and crops.  The District has maintained a continuous corn fertility study, with replicated plots receiving 0 (commercial fertilizer), 16.8, 33.6, and 67.2 Mg biosolids ha-1 annually, since 1973. Samples from 2000 were used to evaluate the effect of long-term biosolids applications on the radioactivity concentration in soil, and the uptake of radioactivity into corn grain and stover. There were no significant differences (p<0.05) in radionuclides concentrations in soil, corn grain and stover among the treatment plots. Of the 27 radionuclides studied, only potassium-40 (grain and stover) and radium-226 (grain) were detected in plant tissue. Long-term annual applications of biosolids did not increase radioactive materials concentration in soil or increase uptake of radioactivity by corn in biosolids-amended soil, compared to fertilized, plots in this study. 

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¹University of Maryland Cooperative Extension, Keedysville, Maryland 21756-1104
²University of Maryland, College Park, Maryland 20742-2315
³Erco, Inc., Glen Burnie, Maryland 21061
*To whom correspondence should be addressed.

Abstract
Using deep row biosolids application to grow hybrid poplar trees (Populus spp.) on sand and gravel mine spoils is a unique and innovative beneficial-use technique that solves many of the conventional problems.  The technique was developed on 50 ha (125 ac) site in the Washington, D.C. metro area by a private company (ERCO, Inc.).  Research has been carried out since 2001 to develop a better understanding of water quality impacts, operational methods, clonal selection, hybrid poplar growth and nutrition, and the factors affecting economics and profitability. There are no indications of nitrate leaching and the tree plantation systems are performing well. Given the large acreage of mine spoils in the metro area, deep row application has the potential to utilize significant amounts of biosolids produced in the region.

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¹Earth Tech, Inc., 21064 Bake Parkway, Suite 200, Lake Forest, California  92630
²Monsal Limited, Oak House, Ransom Wood Park, Southwell Road West, Mansfield
NG21 0HJ, UK
*To whom correspondence should be addressed.

Abstract
The Orange County Sanitation District (OCSD) is upgrading their wastewater treatment Plant No. 1 in Fountain Valley, California. To maintain the 15-day hydraulic retention time (HRT) for meeting EPA 40 CFR Part 503 for Class B biosolids without adding anaerobic digestion volume, it will be necessary to thicken the feed solids to the digesters. An engineering study was conducted to evaluate the effectiveness of the existing jet mixing loop (JML) system for digested sludge concentrations up to 6 percent dry solids (DS). Site-specific sludge rheology data were obtained and used to evaluate digester mixing first in a scale model and then in a computer model using Computational Fluid Dynamics (CFD). The results showed that the JML system would be effective if larger mixing pumps were installed and the mode of operation was modified from parallel jet operation to sequential operation of pairs of jets.

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S. J. Kang¹, P. R. Daukss¹, T. A. Allbaugh¹, K. P. Olmstead¹, B.K. Pineau¹,  V. G. Lochocki¹, L. Thomas², P. Thomas² and T. M. Jessee²

¹Tetra Tech, 710 Avis Dr., Ann Arbor, MI 48108
²Ypsilanti Community Utilities Authority, Ypsilanti, MI
*To whom correspondence should be addressed.

Abstract
The Ypsilanti (Michigan) Community Utilities Authority sought to expand their wastewater treatment facility from 29 MGD to 46 MGD, while producing the cleanest possible air emissions.  After rigorous evaluation of alternatives, fluidized bed incineration was selected as the most favorable biosolids management strategy to replace the prior system that used multiple hearth incineration.    Details on the permit application, regulatory review and public participation are described. The resulting state-of-the-art incineration and air treatment system received the first Michigan Permit-to-Install for such a system in over 20 years. This permit includes stringent emission requirements, elaborate interlocking process parameters, tight operating ranges, and detailed recording and reporting requirements. Construction was completed in late 2005, and start-up was completed in the spring of 2006.    The system includes an 18 ft diameter fluidized bed incinerator, with 4 air cleaning processes: two stages of scrubbers, a wet electrostatic precipitator, and an activated carbon adsorber.

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Mohammad Abu-Orf¹*, Jeff Lambeth² and Gerald Smart²

¹Biosolids Technology Leader, Metcalf and Eddy/AECOM
²Veolia Water, Henderson, NV
*To whom correspondence should be addressed.

Abstract
Residuals generated from biological treatment of perchlorate contaminated groundwater at a treatment facility in Henderson, NV were conditioned with lime and ferric chloride prior to dewatering via standard plate and frame press. Options to enhance dewatering were investigated, including enzyme pre-treatment prior to inorganic conditioning, enzyme treatment prior to polymer conditioning, and polymer conditioning alone. Laboratory tests were conducted using a capillary suction time (CST) test and a bench scale pressure filter device. Results showed that enzyme pre-treatment was capable of enhancing residual dewaterability with either iron/lime or polymer conditioning. Polymer conditioning alone seemed to properly condition the sludge prior to dewatering, and at a low dose of 2-3 lb/DT solids.  Economic evaluation showed that the increase in dewatering performance with enzyme pretreatment did not offset the cost of enzyme addition.  Accordingly, polymer alone was tested at full-scale and results confirmed laboratory findings.  The plant converted to polymer conditioning with satisfactory results.

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Wendy Wert¹*, Dhiru Patel², John Mellin³ and Frank Garza Jr.³

¹Sanitation Districts of Los Angeles County
²LEE & RO, Inc. 1199 South Fullerton Road, City of Industry, CA 91748-1232
³City of Corona, Department of Water & Power, 2205 Railroad St., Corona, CA 92880
*To whom correspondence should be addressed.

Abstract
In southern California, the South Coast Air Quality Management District (AQMD) limits the concentration and mass of hydrogen sulfide (H2S) in gas from all sources (Rule 431.1). Many wastewater treatment plants are successfully applying iron salts to mitigate H2S concentrations in the biogas produced through the anaerobic digestion of biosolids. The iron salt usage at nine facilities was evaluated to assess chemical costs and determine the optimum injection locations. Findings indicate that relocation of the ferric chloride injection point from the primary influent channel to the digesters tends to reduce chemical dose and cost, improve plant aesthetics, and increase the downstream aeration demand. The type of metal salt specified affects location.  Plants observed a dosage gain when injecting ferric into anaerobic environments.  However, the presence of oxygen appears to improve ferrous performance and either form is appropriate for aerobic locations.  The key parameter that controls effective injection is adequate mixing.

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Lita Laven*, Robert Dominak and Frank Foley

¹Northeast Ohio Regional Sewer District
3900 Euclid Avenue, Cleveland, Ohio 44115
*To whom correspondence should be addressed.

Abstract
As more baby-boomer wastewater treatment professionals approach retirement, treatment agencies must take steps to capture and preserve otherwise fleeting institutional knowledge for the next generation of specialists.  The Northeast Ohio Regional Sewer District (the “District”) has established a program for capturing pertinent information and transferring it to junior operators and engineers.  A critical component of the District’s data preservation and transfer program is an empirical study of the impact of two U.S. EPA programs on the quality of the District’s biosolids. Publicly owned treatment works (POTWs) across the United States have realized measurable reductions in the heavy metals and substantial improvements in the quality of their biosolids.  These changes are attributable to the enforcement of two important U.S. EPA regulations: (i) the General Pretreatment Regulations for Existing and New Sources of Pollution (40 CFR Part 403) and (ii) Standards for the Use or Disposal of Biosolids (40 CFR Part 503).

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Hamid Reza Salsali¹ and Wayne J. Parker²*

¹Dept. of Civil and Environmental Engineering, Carleton University, Ottawa, ON
²Dept. of Civil and Environmental Engineering, University of Waterloo, Waterloo, ON, N2L 3G1,
*To whom correspondence should be addressed.

Abstract
This study evaluated the efficiency of three stage operation of anaerobic digestion of municipal sewage sludge.  Various combinations of conventional (35ºC) and non-conventional (42 and 49ºC) temperatures were evaluated.  Three stage operation was able to achieve enhanced volatile solids reduction as compared to single stage operation.  Operation of the first stage at 42ºC and 49ºC resulted in an 8-12% increase in VS destruction.  Stable operation of three stage configurations was indicated by low concentrations of total volatile fatty acids and substantial alkalinity generation.  An increase in temperature to 42ºC in the second stage of the investigated system showed no significant change in final effluent quality. Three stage operation resulted in a greater reduction of all indicator organisms when the first stage of the 3 stage system was operated at either 42ºC or 49ºC as compared to operation at 35ºC. 

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