Enhancing the nitrogen removal from swine wastewater digested liquid in a trickling biofilter with a soil layer

Trickling biofilters (TFs) allow for a simultaneous nitrification and denitrification (SND) process, and offer a favorable solution for the treatment of swine-wastewater digested liquid due to their simple operation and low cost.

Biosolids composting at the Borough of Mechanicsburg, PA WWTP

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 concerns and costs related to the alternatives, biosolids composting was selected to produce a Class A/EQ (Exceptional Quality) biosolids product, thus providing expanded opportunities for beneficial use. From the initial feasibility review to operational status, the implementation spanned nine (9) years, starting in 2005. The upgrade to composting was in conjunction with many other plant upgrades. Material Matters, Inc. provided support through the entire process including the feasibility study, pilot testing, cost assessment, compost facility design requirements, equipment assessment and recommendation, start-up testing, software development, permitting, fertilizer registration, product promotion, and marketing.

Phosphorus availability in residues as fertilizers in organic agriculture

Phosphorus (P) should be recycled from organic wastes as much as possible, and input is needed in stockless organic agriculture. Seven organic residues were assessed and compared them to mineral P fertilizer and rock phosphate as fertilizer for barley. P availability in the mixtures and residual P availability were also assessed by diffusive gradients in thin films (DGT). The best availability was found in digested liquid manure followed by wood ash, fish sludge, composted solid manure and composted food waste. Meat and bone meal, the commercially available product Ladybug plus and rock phosphate had low P availability at the same level as no P. Only wood ash had significant P available for the next crop. The pH level of the soil did not affect P availability for any of the P sources. DGT predicted P availability moderately well, as it measures P supply over a short period without any biological factors.