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Waste Management Research
Chemical precipitation for controlling nitrogen loss during composting

Aimed at controlling the nitrogen loss during composting, the mixture of magnesium hydroxide (Mg(OH) 2) and phosphoric acid (H3PO4) (molar ratio 1:2) were utilized as additives to avoid increasing total salinity. In trial TA, the additives were put into absorption bottles connecting with a gas outlet of fermentor (ex situ method); in trial TB, the additives were directly added to the composting materials (in situ method). During the 26 day composting period, the temperature, pH, total organic carbon (TOC), total nitrogen (TN), ammonium nitrogen (NH4+-N), total phosphorus (TP), available phosphorus (AP) and germination index (GI) were measured. The experimental results show that the additives reduced the pH, while NH 4+-N and TN were obviously improved. NH4 +-N was 11.9 g kg—1 and 3 g kg— 1 in amended compost trial (TB) and unamended compost trial (TA), respectively; TN increased from 26.5 g kg—1 to 40.3 g kg—1 in TB and increased from 26.5 g kg —1 to 26.8 g kg—1 in TA. Analysis of the TOC and carbon mass revealed that absorbents accelerated the degradation of organic matter. The germination index test showed the maturity of TB (102%) was better than TA (82%) in final compost. Furthermore, TP and AP were also obviously improved. X-ray diffraction analysis of precipitation showed that the precipitation in absorption bottle of TA was newberyite (MgHPO 4 3H2O), however, the crystal in the TB compost was struvite (MgNH4PO4 6H2O: magnesium ammonium phosphate). These results indicated that Mg(OH)2 and H3PO 4 could reduce the ammonia emission by struvite crystallization reaction. Optimal conditions for struvite precipitation should be determined for different systems.

4/22/2010 1:29:14 AM
Waste Management Research
Co-digestion of the organic fraction of municipal solid waste with primary sludge at a municipal wastewater treatment plant in Turkey

Co-digestion of the organic fraction of municipal solid waste (OFMSW) and sewage sludge may be an attractive alternative for sustainable management of two separate waste streams produced in large amounts in all countries. This study evaluates calculation-based results of an anaerobic co-digestion process for primary sludge (PS) together with the OFMSW. The calculations were carried out for the anaerobic digester of Kayseri municipal wastewater treatment plant (in Turkey) presently digesting only PS. Two alternatives were proposed using different solid waste contents in co-digesters. For achieving the optimal solids content, some treated wastewater should be recycled to the inlet of the digesters. The municipal solid waste collection method characterized as mechanically sorted (MS-OFMSW; Option 1) is evaluated as well as a source sorted (SS-OFMSW) alternative (Option 2). Utilizing the energy produced by the existing sludge digester, only 30% of the internal energy demand at the wastewater treatment plant can be covered. The aim of this study is to evaluate how energy production would be increased by co-digestion of OFMSW and PS. The best operational condition considering organic loading rate, hydraulic retention time and energy generation could be attained at 10% digester solids content for both options. According to Option 1, almost 77% of the energy demand could be covered by co-digestion of MS-OFMSW and PS. Results indicated that almost 100% energy coverage can be obtained when co-digestion (Option 2) was performed according to SS-OFMSW and PS.

4/22/2010 1:29:14 AM
Waste Management Research
Monitoring of biopile composting of oily sludge

This paper describes a bioreactor set-up used to simulate degradation of petroleum hydrocarbons in a static biopile. The large-scale test was performed in a 28 m3 custom-designed reactor. Oily sludge (40% by weight, having 7% dry matter [DM], and hydrocarbons C10—C40 160,000 mg kg—1 DM) was mixed with organic-rich amendments — mature oil-compost (40%) and garden waste compost (20%). Within the reactor, the temperature and soil gases were monitored continuously during 370 days via 24 measurement points. Also, moisture content was continuously recorded and airflow through compost mix occasionally measured. Three-dimensional ordinary kriging spatial models were created to describe the dynamic variations of temperature, air distribution, and hydrocarbon concentration. There were large temperature differences in horizontal and vertical sections during initial months of composting only. Water content of the mixture was uneven by layers, referring on relocation of moisture due to aeration and condensation. The air distribution through the whole reactor varied largely despite of continuous aeration, while the concentration of O2 was never reduced less than 1—2% on average. The results showed that composting of sludge using force-aerated static biopile technology was justified during the first 3—4 months, after which the masses could be re-mixed and heaped for further maturation in low-tech compost windrows. After 370 days of treatment, the content of hydrocarbons (C 10—C40) in the compost mixture was reduced by 68.7%.

4/22/2010 1:29:14 AM
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....byTotalNews....for PENDPAC

December 27, 2006 TotalNews - Pendpac refuse and collection vehicles reduce workers injuries by 61% in Vancouver, British Columbia. The City of Vancouver and the Vancouver Sun have released statistics to the public in regards to the astounding reduction in worker injuries and sick time off due to Pendpac's automated refuse vehicle aptly named the Alley Gator. "Not only does the Alley Gator greatly reduce job related injuries, the refuse vehicle design also increases collection efficiencies, decreases fuel consumption, and reduces strain on mechanics." stated Steve DeGeorge (President).  Please contact sales@pendpac.com for more information. To read the full article please click here 

September 1, 2006 TotalNews - Pendpac announces the launch of its new customer and partner web portal software. This new content management portal allows customers and partners not only access to information about Pendpac and its products, but allows access to order parts, schedule service, monitor truck build schedules, and communicate better with quality managers. The new content management portal also integrates into Pendpac's production control, inventory, CRM, ERP, and finance platform. "This new system will allow Pendpac complete insight to our organization and help us grow into new product lines while maintaining our commitment to strong customer service and quality control..." stated Steve DeGeorge (President).  Please contact sales@pendpac.com for more information.

August 31, 2006 TotalNews - Pendpac announces the sale of its MABAR Dump Body product line. The MABAR unit was the oldest operating division of Pendpac. It focused on sales, manufacturing, and support for some of the industry' best dump body products. The sale of MABAR to CaseCo, Inc. allows Pendpac to focus on its core refuse product lines and parts sales. Pendpac is expanding its current product lines as well as new refuse vehicles. CaseCo has committed to continuing the excellence and tradition of the MABAR product line and will be expanding its products sets. Please contact sales@pendpac.com for more information.

 August 28, 2006 TotalNews - Pendpac receives expanded customer orders for new "Low Profile" Sprinters. The new Sprinter body allows for the replacement of the "older" style round bodies in the Impac product lines. Several key features to the new design are higher compaction rates, no kick out on the ARM, and quicker curb to curb return cycles while maintaining the height advantages of the round bodies. "The new low profile Sprinter product line is a revolutionary change to a 25 year old product market. Haulers now have the smaller and shorter body styles they have been asking for to better navigate alleys, buildings, and low overhead cables while maintaining maximum packing capabilites." stated Steve DeGeorge (President). Please contact sales@pendpac.com for more information.

May 9, 2007 TotalNews - Pendpac refuse and collection vehicles again plays a part in improving property, environmental, and public safety. Rainbow Disposal of Huntington Beach, Ca. has set up a 2 acre training course for their recently purchased Alley Gator line of waste collection vehicles.  Armando Duarte, the residential supervisor for Rainbow Disposal put it this way, “It’s an educational tool to help with safety and build confidence.” The course is designed not only to familiarize the drivers with the automated arm utilized with the Pendpac Alley Gator units, but; also help them develop speed and precision skills that will reduce injury to the environment and customer property.  Please contact sales@pendpac.com for more information. To read full article click here

 
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