Fuel properties and incineration behavior of poultry litter blended with sweet sorghum bagasse and pyrolysis oil.

The incineration of poultry litter (PL) effectively reduces the volume of waste in line with the United Nations Sustainable Development Goal of "affordable and clean energy". However, mono-incineration is associated with considerable challenges due to the varying moisture, structural and chemical composition and low energy yield. The aim of the present work was to investigate the influence of sweet sorghum bagasse (SS) and pyrolysis oil (PO) on improving the fuel properties of PL and mitigating ash related burdens during incineration. The different biomass feedstocks were produced by combining PL with SS at 0.0% (T0), 25% (T1), 50% (T2), 75% (T3) and compared with 100% SS (T4). In order to achieve high energy potential and low ash deposition, the parallel samples were additionally mixed with 10% PO to improve the energy value. The experimental results show that increasing the proportion of SS and adding PO to the mixtures increases the volatile matter and decreases the moisture and ash content. The addition of PO also increases the carbon and hydrogen content. The use of SS and PO thus increased the values of the ignitability index and apparently also the flammability by 30.0%-49.4% compared to pure PL. SS and PO shifted the HHV of the starting material from 16.90 to 18.78 MJ kg-1. In addition, SS + PO improved the flame volume and red color intensity of the PL blends based on the image analysis method. However, the presence of SS and PO did not sufficiently improve the ash-related index values, which requires further investigation.

Investigation of heavy metal and micro-macro element speciation in biomass ash enriched sewage sludge compost.

The objective of this study was to enrich the nutrient content of compost and to investigate the passivation and solubilization of plant micronutrients (Fe, Al, Cu, Ni, Zn, Na, Mn), macroelements (P, K, Mg, Ca), and heavy metals (Cr, Cd, Pb) during sewage sludge composting with nutrient-rich biomass ash additives. T0: 0%, T1: 3.5%, T2: 7.0%, and T3: 14.0% dry weight (DW), weight/weight (w/w) biomass ash was added to the sewage sludge + sawdust mixture (volume, 1:1) to obtain the final NPK content and monitored over a 45-day period. Sawdust was used as auxiliary material. The sequential extraction method was used to determine the elemental species. Cr, Cd and Pb showed higher affinity to the residual fraction and occluded in the oxide fraction, which decreased the bioavailability factor (BF) (<1% BF-Cr, 21% BF-Cd and 9% BF-Pb) compared to the control treatment (46% BF-Cr, 47% BF-Cd and 80% BF-Pb). As the amount of biomass ash increased (T1-T3), the percentages of residual Cr (Res-Cr) (10-65%), exchangeable Cd (Exc-Cd) and organically bound Cd (Org-Cd) (14% and 21%), and oxides-Pb (Oxi-Pb) (20-61%) increased. In all composts, Fe, Al, and Cu were associated with organically bound and oxides-entrapped fractions. More than 50% of total Mn and Mg were concentrated mainly in exchangeable fractions, suggesting high mobility and bioavailability (42% BF-Mn and 98% BF-Mg). Ni, Zn, and Na tended to be present in oxide-bound, organically bound, and residual fractions, while K and P were associated with exchangeable and organically bound fractions. The overall results suggest that composting sewage sludge with biomass ash may be the best strategy and technique to overcome soil application bottlenecks because it passivates heavy metals and improves the bioavailability of plant nutrients.

A techno-sustainable bio-waste management strategy for closing chickpea yield gap.

Sustainable development goals imply environmentally sound management of all wastes to minimize the waste generation through prevention, reduction, recycling, and reuse. In particular, the poultry industry produces nutrient-rich waste that requires proper management.Additionally, the recycling of bio-wastes in agricultural lands is still a key technology for the sustainable use of nutrients as a renewable fertilizer. Currently, there are very few studies on the utilization of agro-industrial bio-wastes, such as poultry abattoir sludge (PAS), for crop cultivation in soils containing low organic matter and high pH. In this context, it is necessary to make a more particular assessment of poultry industry-oriented and locally available nutrient-rich organic wastes for nodulation, physiological adaptation, and crop yield. Considering the scarcity of the literature in this field, the present study aimed to fulfill the apparent gap by focusing on the applicability of recycled PAS to low fertility soil in the growth of chickpea selected as a model legume, thereby contributing to the development of an agricultural and sustainable industrial management strategy for the relevant sectors. In this study, leaf chlorophyll content and nodule color were also investigated by the image analysis methodology to describe the effects of bio-waste on closing chickpea yield gap in a marginal land with high soil pH and low organic matter. Two-year consecutive field experiments were carried out to explore the effect of the PAS with the application rates of 25 kg N ha-1 (T2), 50 kg N ha-1 (T3), and 100 kg N ha-1 (T4) along with unamended (T0) and fertilized control (T1). The results indicated that the PAS treatments significantly differed in chlorophyll content, nodulation parameters, and biomass and grain yields. The chlorophyll content was correlated (r = 0.910) with the red color value (RGB color model) of nodule image analysis in the response to bio-waste. Based on the two-year average, it was concluded that chickpea yield could be increased 45% by amending with the PAS (T3). The present study clearly demonstrated that the image analysis could be a useful digital tool for the evaluation of chlorophyll content, nitrogen fixation efficiency, and forecasting biomass and grain yields of chickpea. The results also confirmed that the PAS application to low fertility soil could prominently contribute to establish sustainable waste management and crop production alternatives for closing chickpea yield gap.

Enhanced adsorption of methylene blue from textile wastewater by using natural and artificial zeolite.

This study investigated the adsorption of methylene blue with natural and artificial zeolite. The effect of pH, contact time, initial concentration and adsorbent dose on adsorption was also investigated. An artificial dye was prepared. Adsorption removal efficiency was low at pH = 2, 3 and 4 but it was quite high at pH = 7. It was determined that the contact time reaches equilibrium within 60 minutes in the adsorption of methylene blue with natural and artificial zeolite. The initial dyestuff concentration for both adsorbents was 5 mg/L. For the removal of methylene blue, a 0.5 g natural and artificial zeolite dosage was sufficient. In order to express the adsorption of natural and artificial zeolite on methylene blue, Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (D-R) isotherm models were examined. In the isotherm study, both natural and artificial zeolite adapted to the Langmuir isotherm model. Langmuir correlation coefficient was 0.998 for artificial zeolite and 0.993 for natural zeolite. Both adsorbent materials best fit into the pseudo-second kinetic model with similar correlation coefficient values of 0.999.

Mitigation of soil loss from turfgrass cultivation by utilizing poultry abattoir sludge compost and biochar on low-organic matter soil.

Commercial turfgrass cultivation is one of the main ornamental industries world-wide; however, successive turfgrass sod cutting from the same site removes surface soil, leading to a decline in soil organic matter, impairment of soil fertility and degradation of environment. The present study was aimed to investigate the applicability of poultry abattoir sludge compost (PASC) and biochar (BC) on the establishment of turfgrass by evaluating plant growth performance and mitigation of soil loss by organic waste amendments. The experimental study was designed on the soil which had originally low-organic matter content and previously used as a turfgrass sod harvested site in a sandy loam soil. Incorporation of PASC to soil improved the physicochemical properties in terms of bulk density (BD), water holding capacity (WHC), cation exchange capacity (CEC), pH, total nitrogen, total organic carbon (TOC), and organic matter (OM) by 37 (±2)%, 45 (±3)%, 55 (±3)%, 21 (±2)%, 48 (±2)%, 90 (±10)%, and 96 (±4)%, respectively. PASC-amended treatments enhanced the turfgrass growth rate more than the BC due to its increased nutrient availability. Incorporation of 100 Mg ha-1 (mega gram per hectare) PASC in surface soil with or without BC decreased the mineral soil removal rate by half of the respective soil (control) treatments. The results of the present study confirmed the utilization of PASC and BC as promising agro-industrial-based fertilizers in turfgrass sod production for sustainable soil and nutrient management.

Development of nutrient-rich growing media with hazelnut husk and municipal sewage sludge.

The aim of the present study was to develop structurally stable, nutrient-rich and environmentally safe growing media by combining waste material: crop residue hazelnut husk (HH) and municipal sewage sludge. In order to achieve this goal, lignocellulosic HH residue was mixed with nutrient-rich sewage sludge (S) in various proportions: HH 100%; HH + S1 87.5% : 12.5%; HH + S2 75% : 2 5%; HH + S3 50% : 5 0%. Following composting, the key physical, chemical and microbiological properties of the growing media were characterized for long-term ornamental nursery crops. The addition of S to the mixture had both significant detrimental and remedial effects on physical properties such as reduced total porosity and water-holding capacity, whilst improved the air capacity, wettability and shrinkage. S content of growing media significantly enriched the plant nutrients, especially the most desired soluble and organic nitrogen fractions and micro nutrients. Germination tests and microbiological analysis confirmed the products as environmentally safe ornamental growing media. We conclude that composting of HH with S is a viable alternative for the development of nutrient-rich growing media and recycling of such waste in the ornamental industry could be a beneficial method in order to sustain waste management and crop production.

Effects of elemental sulphur on heavy metal uptake by plants growing on municipal sewage sludge.

In this study experiment was carried out to determine the phytoextraction potential of six plant species (Conium maculatum, Brassica oleraceae var. oleraceae, Brassica juncea, Datura stramonium, Pelargonium hortorum and Conyza canadensis) grown in a sewage sludge medium amended with metal uptake promoters. The solubility of Cu, Cd and Pb was significantly increased with the application of elemental S due to decrease of pH. Faecal coliform number was markedly decreased by addition of elemental sulphur. The extraction of Cu, Cr and Pb from sewage sludge by using B. juncea plant was observed as 65%, 65% and 54% respectively that is statistically similar to EDTA as sulphur. The bioaccumulation factors were found higher (>1) in the plants tested for Cu and Pb like B. juncea. Translocation index (TI) calculated values for Cd and Pb were greater than one (>1) in both C. maculatum and B. oleraceae var. oleraceae. The results cleared that the amendment of sludge with elemental sulphur showed potential to solubilize heavy metals in phytoremediation as much as EDTA.

Comparison of composted biosolid substrate for containerized turfgrass production.

Composts produced from composting municipal sewage sludge with bulking agent, namely hazelnut husk (HH), pine litter (PL), corn straw (CS) and sawdust (SW), were seeded with turfgrass mix and cultivated in a container to compare the suitability of composted substrates to produce turfgrass in greenhouse conditions. The performance of substrate was determined by both substrate properties compared to standard peat and by measuring plant growth parameters on each substrate during turfgrass sod establishment. In general, the physico-chemical properties of all substrates were satisfactory for container substrates, but HH and PL substrates performed better in plant growth parameters than in SW and CS composts. The comprehensive growth index values obtained for plants growing in peat, HH and PL were 0.94, 0.87 and 0.84, respectively, which were higher than those in the CS and SW. Plant growth showed linear above-ground dry matter accumulation in all substrates, but was slower in SW and CS. HH and PL substrates appeared to be suitable for containerized sod production for natural soil and peat substitution. Biosolid proved to be an efficient component as a nutrient source ingredient of composted substrates for turfgrass.

Effect of solarization on the removal of indicator microorganisms from municipal sewage sludge.

The effect of solarization on bacterial inactivation in sewage sludge was studied using thermotolerant coliforms, enterococci and Escherichia coli (E. coli) as the indicator organisms. Solarization significantly increased the sludge temperature. The maximum temperatures were achieved at the beginning of the second week, reaching 65, 58, 55 and 50 degrees C at depths of 0-10, 10-20, 20-30 and 30-40 cm, respectively. E. coli was found to be the most sensitive microorganism and was reduced to undetectable levels after 9 d at all monitored sludge depths. Thermotolerant coliforms were rapidly inactivated but were not reduced to below the detection limit. The inactivation curves of enterococci showed both shoulders and tailing, indicating a larger heat resistant fraction than with E. coli and the thermotolerant coliforms. Overall, the results suggest that the temperature regime produced by solarization was sufficient to reduce bacterial indicators to an acceptable level, meeting the pathogen regulation limit, in two weeks.