Expanding DEMON Sidestream Deammonification Technology Towards Mainstream Application.

A cross-Atlantic R&D-cooperation involving three large utilities investigated the feasibility of mainstream deammonification-the application of partial nitritation/anammox for full-plant treatment of municipal wastewater at ambient temperatures. Two major process components have been implemented, 1) bioaugmentation of aerobic- and anaerobic ammonia oxidizers (AOB and AMX) from the DEMON-sidestream sludge liquor treatment to the mainstream and 2) implementation of hydrocyclones to select for anammox granules and retain them in the system. Different operation modes have been tested at laboratory- and pilot-scale in order to promote the short-cut (more direct anammox route) in nitrogen removal metabolism. At the full-scale installation at Strass WWTP, stable repression of nitrite oxidizing biomass (NOB) has been achieved for several months. Significant anammox enrichment in the mainstream has been monitored while high efficiency in the sidestream-process has been maintained (96% annual average ammonia removal).

Merging two waste streams, wood ash and biowaste, results in improved composting process and end products.

A trial was carried out to evaluate the influence of wood ash admixture on biowaste composting. The aim was to find the optimal dosage of ash addition to enhance the composting process without endangering the final compost characteristics and use. Six treatments including an unamended control (K0) and composts with additions of 3% (K3), 6% (K6), 9% (K9), 12% (K12) and 15% (K15) of wood ash (w/w) were studied. The composting process was monitored in situ for 49days, by measuring temperature, CO2, O2, and CH4 in the piles and pH, electric conductivity (EC), and inorganic N in the laboratory. At the end of the process, the products were tested for Reifegrad (maturity), toxicity and quality. The addition of up to 15% of wood ash to biowaste did not negatively affect the composting process, and the initial differences found between both the low and high ash-treated composts were attenuated with the ongoing process development. Nevertheless, and mainly due to Cd level, composts with higher ash amendment did not comply with the highest quality standards established by the Austrian Compost Ordinance. The failure of obtaining class A+ quality after ash amendment emphasizes the need for a rigid quality selection of (bottom) ashes and thus reducing environmental risks related to high pollutant loads originating from the ashes.

Going for mainstream deammonification from bench to full scale for maximized resource efficiency.

A three-pronged coordinated research effort was undertaken by cooperating utilities at three different experimental scales investigating bioaugmentation, enrichment and performance of anammox organisms in mainstream treatment. Two major technological components were applied: density-based sludge wasting by a selective cyclone to retain anammox granules and intermittent aeration to repress nitrite oxidizers. This paper evaluates process conditions and operation modes to direct more nitrogen to the resource-saving metabolic route of deammonification.

A new combination of extraction and derivatization methods that reduces the complexity and preparation time in determining phospholipid fatty acids in solid environmental samples.

Combinations of three extraction methods (modified Folch method, modified Bligh and Dyer and microwave-assisted extraction (MAE)) and two derivatization methods (alkaline methanolysis and derivatization with trimethylsulfonium hydroxide (TMSH)) are compared for determining phospholipid fatty acids (PLFAs) in soil and solid organic samples (animal manures, compost and vermicompost). The modified Folch method rendered the greatest total amount of PLFAs and the highest yields of individual PLFA biomarkers; the effect was most apparent in the vermicompost samples. MAE rendered similar extraction yields as the modified Bligh and Dyer method (the most commonly used extraction method), although MAE is much simpler and faster. The highest conversion yields of PLFAs into fatty acid methyl esters were achieved with TMSH as the derivatization agent. The modified Folch method together with derivatization with TMSH was the least complex and time consuming method of determining microbial community structure in solid environmental samples.