Energy-Positive Disintegration of Waste Activated Sludge—Full Scale Study

This study aimed to evaluate the effects of mechanical disintegration of waste activated sludge (WAS) on full scale anaerobic digestion, considering the possibility of obtaining a positive energy balance. The results showed that an increase in energy density (εL) used in disintegration was accompanied by an increase in the release of organic compounds from sludge (SCOD increased from 211 ± 125 mg O2/L for εL = 0 kJ/L to 6292 ± 2860 mgO2/L for εL = 180 kJ/L). Some of them were volatile fatty acids. The percentage share of WAS subject to disintegration was also documented as a crucial parameter affecting the efficiency of biogas production. An increase in the value of this parameter from 25% to 100%, even at much lower εL used in disintegration (therefore with much smaller amounts of organic compounds released from sludge flocs) resulted in an increase in biogas production. Conducting disintegration of the entire stream of WAS directed to the fermentation tank at εL 30 kJ/L resulted in an increase in biogas production by 14.1%. Such a surplus would allow production of approximately 360 kWh/d net electricity. Mechanical disintegration of thickened WAS therefore may be an economically justifiable strategy for the intensification of anaerobic sludge stabilisation.

Mechanical Disintegration and Particle Size Sieving of Chondrus crispus (Irish Moss) Gametophytes and Their Effect on Carrageenan and Phycoerythrin Extraction

To better understand the migration properties of hybrid carrageenan from the seaweed tissue during carrageenan extraction, the effect of increasing the seaweed surface area by the mechanical disintegration of gametophyte Chondrus crispus chips was studied under various temperature and time extraction conditions. Dried Chondrus crispus seaweed chips were milled by a rotor beater mill and classified into eight different size fractions by sieving with varying mesh sizes from 50 to 2000 μm. During extraction at 22 °C, the red color of the filtrate increased significantly with the decreasing particle size of the fraction, correlating with the increasing phycoerythrin concentration (from 0.26 mg PE/g dry seaweed in the >2000 μm size fraction to 2.30 mg PE/g dry seaweed in the <50 μm size fraction). On the other hand, under the same extraction conditions, only a small increase in carrageenan precipitate was obtained with the decreasing size fractions (from no recovery in the >2000 μm size fraction to 2.1 ± 0.1 g/kg filtrate in the <50 μm size fraction). This yield was significantly lower than the ones from extractions at 45 °C (5.4 ± 0.1 g/kg) or at 90 °C (9.9 ± 2.1 g/kg) for the same particle size and time conditions. It could be concluded that hybrid carrageenan extraction is not surface area dependent, while phycoerythrin is. Therefore, it seems that phycoerythrin and carrageenan extraction follow different mechanisms. This creates potential for the selective extraction of each of those two compounds.

Compression-molded products based on wet ball-milled wood and effect of various preparation conditions

This study prepared compression-molded products from ball-milled wood by thermally plasticizing lignin without adhesives or resins. Wet ball milling for 120 min produced smooth, creamy slurries. The resultant products were hot-pressed at 180 °C and exhibited a plastic-like glossy surface and a high Young’s modulus (7.9 GPa), which was attributed to an increased bonding area. However, hydrogen bond formation occurs more predominantly during wood molding than thermoplasticization of lignin, because a hydrophilic surface was formed on wood fragments after wet ball milling in water. In contrast, when wood powder was ball-milled in toluene, drying aggregation due to hydrogen bond formation hardly occurred probably because the hydrophobic regions were preferentially cleaved. In this case, the hot-pressed product at 180 °C was formed mostly through the bonding owing to the thermoplasticization of lignin. These results suggest that the choice of the solvent for the mechanical disintegration of wood allows for control of the wood fragment surface and can affect the properties of the molded products.

High-strength cellulose nanofibers produced via swelling pretreatment based on a choline chloride–imidazole deep eutectic solvent

A deep eutectic solvent based on choline chloride and imidazole was investigated for swelling of cellulose fibers prior to mechanical disintegration into cellulose nanofibers.

Clinical, Parasitic, and Histopathological Study of Pigeons Infested with Raillietina spp in Al-Qadisiyah Province, Iraq

Pigeons, in Al-Qadisiyah Province-Iraq, were investigated Clinically, parasitically, and histopathologically for the presence of Raillietina spp in their intestines. For these reasons, 5 cities from the mentioned province above were sampled as 150 (100 males and 50 females) pigeons were studied. The general clinical inspection, intestinal exploration and slides for the worms, and histopathological slide sections for the infested intestines were performed. The results of the clinical studies revealed delay growth in the young birds and emaciation in the adult pigeons. For the parasitic characteristics in the intestines, the results showed clearly the presence of Raillietina spp, declaring by their firmly attachment to the mucosa by their suckers and showing their segments, in the lumens of the small intestines. In the case of histopathological pictures, intestines revealed grossly small-intestine-wall-based enlargement and obstruction via intussception caused by the tapeworm presence with huge amounts of mucus and air bubbles and the parasitic white convoluted tracks in the intestinal mucosa. Microscopically, the results recognized that mucosa had mechanical disintegration, marked sloughing of the epithelial layers that belonged to the villi and crypts, epithelial-cell-based desquamation of the villi that were affected by dwarfism, mucosa and submucosa infiltration with mononuclear cells. This study provides important clinical, parasitic, and histopathological data of pigeons infested with Raillietina spp in AlQadisiyah Province, Iraq.