Development of phytotoxicity indexes and their correlation with ecotoxicological, stability and physicochemical parameters during passive composting of poultry manure

Abstract

Both raw and composted poultry manure is applied as soil amendment. The aims of this study were: (1) to develop phytotoxicity indexes for organic wastes and composts, and (2) to assess the correlation among phytotoxicity indexes, ecotoxicological endpoints and stability and physicochemical parameters during passive composting of poultry manure. Six 2-m(3) composting piles were constructed and four parameter groups (physicochemical and microbiological parameters, ecotoxicological endpoints, and biological activity) were determined at four sampling times during 92days. Extracts were used to carry out acute toxicity tests on Daphnia magna, Lactuca sativa and Raphanus sativus. Composting decreased average toxicity 22.8% for the 3 species and D. magna was the most sensitive species. The static respiration index decreased from 1.12 to 0.46mgO2gOMh(-1) whilst organic matter reduced by 64.1% at the end of the process. Escherichia coli colonies remained higher than values recommended by international guidelines. The D. magna immobilization test allowed the assessment of possible leachate or run-off toxicity. The new phytotoxicity indexes (RGIC0.8 and GIC80%), proposed in this study, as well as salinity, proved to be good maturity indicators. Hence, these phytotoxicity indexes could be implemented in monitoring strategies as useful ecotoxicological tools. Multivariate analyses demonstrated positive correlations between ecotoxicological endpoints (low toxicity) and biological activity (stability). These two parameter groups were associated at the final sampling time and showed negative correlations with several physicochemical parameters (organic and inorganic contents). The final poultry manure compost was rendered stable, but immature and, thus, unsuitable for soil amending.

Nitrogen Isotope Fractionation during Composting of Sewage and Agri-Food Sludge with Pruning Waste

“…All the composts had OM concentrations higher than 35%, AS composts showing in general the highest OM contents, with similar values to those obtained by Vico et al [9] and Morales et al [11] during the co-composting of agri-food sludge. CEC and CEC/TOC ratio are parameters usually considered to evaluate compost maturity [36,37]. The values of the CEC and CEC/TOC ratio differed greatly among the obtained composts (Table 6).…”

Assessment of biowaste composting process for industrial support tool development through macro data approach

“…There are different methods that allow monitoring the composting process but that requires periodical sampling that cannot be considered in the current operations of the plants (moisture, temperature, gases), because not all facilities have Programmable Logic Controller (PLC) installed for process monitoring, and frequent expenses that cannot be afforded. Unfortunately, there is not a great amount of bibliography focused on measuring the efficiency of the composting process, some bibliography only focuses on the evolution of organic matter or chemical parameters to determine the efficiency of plants (Adani et al, 1997;Biasioli et al, 2009;Colón et al, 2017;Young et al, 2016), or work with modelling processes (Rafiee et al, 2017).…”

Evaluation of phytotoxicity of three organic amendments to collard greens using the seed germination bioassay

“…The seed germination bioassays were also used to monitor the stability and maturity of composts (Hase and Kawamura 2012 ; Tiquia 2010 ; Young et al 2016 ). During composting, bacteria degrade the organic matter in the composted material.…”