Search

The dewaterability of pulp and paper sludges is usualy poor. In this study, biological sludge samples from two pulp and paper mills were conditioned with three cationic polyelectrolytes that have similar molecular weights and different charge densities. Cationic polyelectrolyte of high charge density could efficiently enhance sludge dewaterability and markedly reduce the residual moisture content in the dewatered cake. On the other hand, the introduction of seawater to pulp and paper sludge would increase the demand of the cationic polyelectrolyte.

Hysteresis in the equibrium moisture content and differences in the paper strength caused hereby, were measured and at the same time the error variances were calculated.The results were summarized as follows ;(1) The air circulated over the sample for 6 hours at the rate of not less than 1.8m/sec.. it is sufficient to conditioning except highly moisture-resistant paper such as hard-sized paper and paperboard.(2) The greatest difference between the equiribrium moisture contents was observed in groundwood as much as 2 %.(3) Consequently, the tensile strength differs not less than 10% in newsprint.(4) The differences in strength as well as in equiribrium moisture content were reduced according to the degree of pulping process.(5) Almost all papers were signified the variance in strength at 5 % level except the folding endurance.(6) The coefficient of variation was grown up in proportion to the difference in strength caused by hysteresis.(7) Increased the measuring area of a test piece decided by tester type (such as folding endurance, tearing strength, bursting strength and tensile strength.) decreased the coefficient of variation.

In spite of the well-established concept in this country that the humidity conditioning of paper before being printed on an offset press is essential to achieve a good registering, increasing number of printers have been working to eliminate this troublesome procedure from their processes. In an effort to assist this movement from the papermaker's standpoint, significance of humidity conditiong has been reexamined, placing emphasis on its effect on the registering characteristics of coated papers. From the results of registering experiment on a commercial offset press, it is indicated that the humidity conditioning of paper can not be a cure-all by itself. A sheet of poor physical condition with high degree of accumulated stresses is partially stress-relieved, but not to a satisfactory extent unless an inefficient long maturing at a very high relative humidity is applied. On the other hand, only a slight effect of conditioning is observed to be supplemental with a sheet of originally gocd registering characteristics. These results are supported by the supple mental data on the effect of humidity cycling in the relative humidity range of 25-65-95% on the physical properties of coated sheets, such as dimensions, moisture content, humidity expansion and contraction, and water expansion. Based on the above observations, the papermaker's part in the project of eliminating humidity conditioning at printing plants is discussed. It is believed to be essential for a papermaker to deliver an originally docile sheet with minimum accumulated stresses, which may not be obtained through a mere moistening treatment afterwards.

Conditioning can drastically improve the dewaterability of sewage sludge and is widely practiced in most wastewater treatment plants (WWTPs). Sludge conditioning was also reported as a crucial step in sludge treatment to attenuate antibiotic resistance, but it remains unclear whether the attenuated antibiotic resistance by conditioning treatments would guarantee low abundance of antibiotic resistance genes (ARGs) in the compost products of municipal sewage sludge. Herein, the impacts of three conditioning treatments, including bioleaching and chemical conditioning using Fe[III]/CaO or polyacrylamide (PAM), on the abundances of 20 ARGs and 4 mobile genetic elements (MGEs) during conventional aerobic composting of dewatered sludge were investigated. It was found that the absolute and relative abundances of total ARGs in compost product of bioleached sludge accounted for only 13.8%-28.8% of that in compost products of un-conditioned, Fe[III]/CaO-conditioned, or PAM-conditioned sludges. Besides, bioleaching conditioning resulted in the lowest abundances of ARG subtypes and ARG-associated bacteria in the sludge compost product. The shift of ARG profiles in the bioleached sludge composting can be mainly ascribed to the ARG-associated bacteria, while the MGEs drove the ARG profiles during conventional composting of un-conditioned sludge and the two chemically conditioned sludge. Thus, bioleaching conditioning is superior to the chemical conditioning using Fe[III]/CaO or PAM in mitigating antibiotic resistance in sludge compost products, which was contributed by the pre-removal of ARGs prior to composting treatment and the potential limitation of ARGs transfer during conventional composting.

Cotton fiber is the most important raw material of the textile industry. Agricultural activities, harvesting methods, storage, ginning, and spinning process are important in determining the quality...

The management and disposal of excess sludge are emerging issues owing to the high costs associated with treatment. In this study, the viability of a modified bentonite was investigated as a conditioning agent for the stabilisation of heavy metals (i.e., Cu, Zn, Cr, Pb, and Cd) and the retention of nutrient species (i.e., total nitrogen (TN), total phosphorus (TP), available nitrogen (available N), and Olsen-phosphorus (Olsen-P)) in sewage sludge for agricultural use. Five grams of modified bentonite resulted in the highest stabilisation rate of heavy metals and strongly contributed to the stabilisation of heavy metals. However, increased amounts of modified bentonite might increase the TN, available N, and TP losses in the conditioned sewage sludge. Through the analytic hierarchy process modelling, optimal concentrations of nutrient species and heavy metals remaining in the conditioned sewage sludge were achieved when the ratio of bentonite to sewage sludge was 1:12.5 (4 g bentonite : 50 g sludge). Moreover, the optimal mixing ratio of the conditioned sewage sludge to the soil (1:2) was suggested for agricultural use. Based on these observations, modified bentonite allowed the sewage sludge to be used as a fertiliser in agriculture by stabilising heavy metals and retaining nutrient species. HIGHLIGHTS The modified bentonite stabilised the heavy metals and retained the nutrient elements in the sewage sludge.; The AHP modelling revealed the optimal ratio of bentonite to sewage sludge (4 g bentonite : 50 g sludge).; The optimal mixing ratio of the conditioned sewage sludge to the soil (1:2) was suggested for agricultural use.; The modified bentonite allowed sewage sludge to be used as a fertiliser in agriculture.

The study aimed to evaluate the effects of 1 vs. 2 sessions per week of equal-volume sprint training on explosive, high-intensity and endurance-intensive performances among young soccer players. Thirty-six young male soccer players were randomly divided into 2 experimental groups that performed either a single weekly sprint training session (ST1, n = 18, age: 17.2 ± 0.8 years) or two weekly sprint training sessions (ST2, n = 18; age: 17.1 ± 0.9 years) of equal weekly and total volume, in addition to their regular soccer training regimen. Linear sprinting (10 m, 20 m, 30 m, and flying 10 m), T-test agility, countermovement jump (CMJ) and maximal oxygen consumption were assessed one week before (T1), in the middle (T2) and immediately after the 10 weeks of training (T3). A large magnitude and statistically significant main effect for time was found in all the assessed variables after both training interventions (all p < 0.001; ES ≥ 0.80). No main effect was observed between the 2 groups at any time in linear sprinting, T-test or CMJ test (p > 0.05; ES < 0.20). A significant interaction effect (F = 4.05; p = 0.04, ES = 0.21) was found for maximal oxygen consumption with ST2 inducing better performance than ST1 (p = 0.001; ES = 1.11). Our findings suggested that the two sprint training frequencies were effective in enhancing explosive, high-intensity and endurance-intensive performances. However, it is recommended for coaches and fitness coaches to use a biweekly sprint training modality as it was found to be more effective in improving endurance-intensive performance.

In this work, heat-activated peroxymonosulfate (heat-PMS) oxidation was used to condition waste activated sludge. The results showed that the optimal temperature and PMS dosage for sludge dewatering were 75 °C and 150 mg/g-volatile solids (VS), and the addition of rice husk (100–400 mg/g-VS) was favorable to further enhance sludge dewaterability. Under optimal conditions, the capillary suction time reduction and water content of sludge cake were 82.4% and 65.8%, respectively. The significant improvement of sludge dewaterability was ascribed to the releases of extracellular polymeric substances (EPS)-bound water and cell water caused by the significant breakdown of tightly bound EPS, as well as the skeleton effect. In addition, heat-PMS oxidation has been demonstrated with the merits of improving the immobilization of heavy metals (HMs) and weakening their environmental risk. After conditioning, HMs solubilization was enhanced significantly and their leaching toxicity decreased obviously. Meanwhile, HMs were transformed into more stable forms. Therefore, heat-PMS oxidation might be a potential and desirable technology for sludge conditioning with respect to the enhancement of sludge dewaterability and the decrease of HMs environmental risk.

The highly-emulsified oily sludge in gas fields is complex in components and serious in emulsification, which makes effective reduction extremely difficult only by a single direct mechanical separation method such as microwave heating, ultrasonic treatment, chemical conditioning, etc. In view of this, this paper presented a new chemical–physical compounding conditioning technology for such highly emulsified oily sludge in gas fields. The experimental samples, from the Mizhi Natural Gas Processing Plant of PetroChina Changqing Oilfield Company, were treated through chemical conditioning, from which the optimal formula, dosages and dosing order were determined. On this basis, the compound technology of chemical–physical conditioning was applied to reduce the specific resistance to filtration (SRF) of the sludge, thus achieving a satisfactory result. The following results were obtained. (1) The chemical conditioning agent with the formula of the oxidant MN-S, calcium oxide and sodium hydroxide was proved to achieve the fastest dewatering speed, and the specific resistance of sludge can be reduced from 130.3 to 3.81 trillion m3 per kg. (2) Comparison between microwave and ultrasonic conditioning methods shows that the latter is better in reducing the SRF (the ultrasonic frequency of 40 kHz was applied to reduce the SRF down to 14.01 trillion m3 per kg after 4 min of conditioning treatment). (3) The ultrasonic treatment effect after chemical conditioning is the best; the SRF was reduced to 2.77 trillion m3 per kg, and the moisture content of the sludge after mechanical dewatering was only 68.71%, decreased by 21.46% compared with the original content of 90.17%. In conclusion, this presented chemical–microwave–ultrasonic compound conditioning technology can reduce the sludge's SRF and the moisture content of filter cakes so as to achieve effective reduction of the highly-emulsified sludge in gas fields. Keywords: Highly emulsified oily sludge, Microwave conditioning, Ultrasonic conditioning, Chemical conditioning, Chemical–Physical compound conditioning, Specific resistance to filtration (SRF) of sludge, Effective reduction

Key points In people or animals with incomplete spinal cord injury (SCI), changing a spinal reflex through an operant conditioning protocol can improve locomotion.All previous studies conditioned the reflex during steady‐state maintenance of a specific posture. By contrast, the present study down‐conditioned the reflex during the swing‐phase of locomotion in people with hyperreflexia as a result of chronic incomplete SCI. The aim was to modify the functioning of the reflex in a specific phase of a dynamic movement.This novel swing‐phase conditioning protocol decreased the reflex much faster and farther than did the steady‐state protocol in people or animals with or without SCI, and it also improved locomotion.The reflex decrease persisted for at least 6 months after conditioning ended.The results suggest that conditioning reflex function in a specific phase of a dynamic movement offers a new approach to enhancing and/or accelerating recovery after SCI or in other disorders. Abstract In animals and people with incomplete spinal cord injury, appropriate operant conditioning of a spinal reflex can improve impaired locomotion. In all previous conditioning studies, the reflex was conditioned during steady‐state maintenance of a stable posture; this steady‐state protocol aimed to change the excitability of the targeted reflex pathway; reflex size gradually changed over 8–10 weeks. The present study introduces a new protocol, comprising a dynamic protocol that aims to change the functioning of the reflex pathway during a specific phase of a complex movement. Specifically, we down‐conditioned the soleus H‐reflex during the swing‐phase of locomotion in people with hyperreflexia as a result of chronic incomplete SCI. The swing‐phase H‐reflex, which is absent or very small in neurologically normal individuals, is abnormally large in this patient population. The results were clear. With swing‐phase down‐conditioning, the H‐reflex decreased much faster and farther than did the H‐reflex in all previous animal or human studies with the steady‐state protocol, and the decrease persisted for at least 6 months after conditioning ended. The H‐reflex decrease was accompanied by improvements in walking speed and in the modulation of locomotor electromyograph activity in proximal and distal muscles of both legs. These results provide new insight into the factors controlling spinal reflex conditioning; they suggest that the conditioning protocols targeting reflex function in a specific movement phase provide a promising new opportunity to enhance functional recovery after SCI or in other disorders., Key points In people or animals with incomplete spinal cord injury (SCI), changing a spinal reflex through an operant conditioning protocol can improve locomotion.All previous studies conditioned the reflex during steady‐state maintenance of a specific posture. By contrast, the present study down‐conditioned the reflex during the swing‐phase of locomotion in people with hyperreflexia as a result of chronic incomplete SCI. The aim was to modify the functioning of the reflex in a specific phase of a dynamic movement.This novel swing‐phase conditioning protocol decreased the reflex much faster and farther than did the steady‐state protocol in people or animals with or without SCI, and it also improved locomotion.The reflex decrease persisted for at least 6 months after conditioning ended.The results suggest that conditioning reflex function in a specific phase of a dynamic movement offers a new approach to enhancing and/or accelerating recovery after SCI or in other disorders.

This paper presents the influence of different methods of sewage sludge conditioning on the effectiveness of dewatering. In the laboratory research, three conditioning methods were tested: (1) with the use of biomass ash, (2) chemical conditioning by means of polyelectrolyte and (3) dual conditioning with the application of biomass ash in conjunction with polyelectrolyte. The specific resistance to filtration, the moisture content and characteristics of filtrates were measured. The influence of sludge conditioning on capillary suction time and the initial pH was also examined. The obtained results showed that MC and SRF decreased after sludge conditioning. Among all tested methods, the dual conditioning influenced the sludge dewaterability to the highest extent. Due to their effectiveness, physical and dual conditioning methods might be a promising alternative for the application of polyelectrolytes. The reduction of polyelectrolyte consumption has also economic benefits, which was confirmed in a previous economic analysis.

Fenton conditioning processes have been recently employed to improve the dewaterability of sewage sludge. However, it remains unclear whether the conditioning with Fenton's reagent would simultaneously attenuate antibiotic resistance genes (ARGs) in sludge and improve sludge dewaterability. It was found in the present study that sludge pre-acidification played a pivotal role in simultaneously removing ARGs and improving sludge dewaterability by conditioning with Fenton's reagent. When the sewage sludge was pre-acidified to pH = 3.0 and was then conditioned using Fenton's reagent, the absolute abundances of the total ARGs and the total mobile genic elements (MGEs) in conditioned sludge were reduced by 1.85-2.10 and 2.84-3.12 log units, respectively. Additionally, sludge capillary suction time (CST) and specific resistance to filtration (SRF) were drastically reduced, and the moisture content (MC) in dewatered sludge cake was reduced to only 60.61-69.95%. Such effective attenuation of ARGs and MGEs in conditioned sludge led to their removal in both the dewatered sludge cakes and dewatering filtrate. However, only the improvement of sludge dewaterability was attained by sludge conditioning with Fenton's reagent but without sludge pre-acidification. During the conditioning treatment, the removal of loosely bound extracellular polymeric substance (EPS) and tightly bound EPS in conditioned sludge contributed to the improvement of sludge dewaterability, and the damage of sludge microbial cells was highly correlated with the attenuation of antibiotic resistance. Thus, sludge pre-acidification combined with conditioning using Fenton's reagent can be employed to simultaneously attenuate the antibiotic resistance in sewage sludge and improve sludge dewaterability.

The effect of stirring and attrition-scrubbing conditioning pretreatment on organic content enrichment was investigated. A relatively coarse particle size (−0.5 + 0.1 mm) was used to avoid high com...

—The gross calorific value of wet-quenched blast-furnace coke fluctuates significantly as a function of the piece size. It is greatest for the

Background: Bael is an important indigenous fruit, which is rich in nutritional and health promoting factors. Development of value-added products from this fruit poses a problem as the fruit has a hard rind and is difficult to be removed by hand. Methods: The objective of this investigation was to evaluate the effect of different conditioning methods as normal water dipping (25-27°C), chilling (10-11°C), freezing (4-5°C) and hot water dipping (90-95°C) on firmness and other mechanical properties of raw and matured bael fruit, with a goal of devising some methods for easy removal of the rind. The fruits after conditioning were subjected to puncture test by universal testing machine. Distinct peaks were observed on the force-displacement traces which indicated the rupture force and firmness of the fruits. The changes observed in rupture force, deformation and firmness in conditioned samples were compared. Result: Rupture force measured for control sample (kept under ambient conditions) was 344.4±27.13 N and was found to be lower than that of the conditioned samples. The minimum rupture force of 192.6±14.41 N was observed in frozen sample. No significant difference in rupture force could be observed between the normal water dipped sample and chilled samples. Hot water dipped sample required a rupture force of 215.3±29.2 N, which was not significantly (p greater than 0.05) less than those of other treatments but, the green color of the fruits degraded to brown. The change in other mechanical properties also remained similar. The results would be useful for preparing the raw bael fruit for further processing and value addition.

The effects of lysozyme (LZM) and freeze-thaw conditioning, alone or in combination, on sludge dewatering performance were comparatively investigated. After the optimization of the dewatering conditions using response surface methodology (RSM), the co-conditioning exhibited obvious superiority to the separate conditioning in improving the dewaterability of municipal sludge, with the capillary suction time (CST) and the water content (W) of the dewatered sludge reduced to 12 ± 0.5 s and 52.0% ± 0.4% from 61.8 s and 73.0%, respectively. The co-conditioning appeared not only to destroy the structure of extracellular polymeric substance (EPS) and microbial cell wall by virtue of enzymatic conditioning, but it formed larger particles and compact sludge floc structure with the help of freeze-thaw conditioning. Additionally, the bound water content of sludge decreased by 47.5% after co-conditioning, consistent with the enhancement in sludge dewaterability. All the results showed that LZM in combination with freeze-thaw conditioning had a great potential in sludge reduction, providing more opportunity of resource utilization for the dewatered sludge.

Sewage sludge, the most important by-product of biological wastewater treatment, is considered an important source of secondary pollution in environments. Simultaneously, sewage sludge is rich in nutrients and organic matter, therefore it is proposed for natural use. However, before such an application, sewage sludge should be properly prepared, so that it does not adversely affect on the environment. Apart from various methods commonly applied in sewage sludge conditioning, the utilization of bio-preparations seems to be an attractive alternative. The experiment was conducted in PVC boxes with one sewage sludge and one amendment treatment as Effective Microorganism (EMTM) preparation applied at two doses dissolved (the water: EMTM preparation ratio = 1:5) (T1) and concentrated (T2). Sewage sludge without EMTM preparation was a control treatment (T0). The chemical composition of sewage sludge was recorded at 12 incubation dates. The quantitative changes of macro and micronutrients during incubation sewage sludge were assessed and followed by evaluated by distance covariance which measure both linear and nonlinear relationship between variables. On the base of obtained results, one may state, that the significance of EMTM preparation in sewage sludge conditioning was minor. The positive effect of the bio-preparation was observed only in the case of carbon and nitrogen, which amounts increased along the incubation time. These conclusions were obtained thanks to the author’s method of selecting variables based on the covariance distance defined for multidimensional functional data. There is no doubt that modern statistical methods based on functional data lead to in-depth conclusions resulting from the conducted experiment.

It was found that the obtaining of quality 3D printing filaments, without defects and natural color, from corn starch physical modified with PVOH, depends also on the melting behavior at compounding, both of starch and of PVOH, and on the controlling of the process sensitivity of the new compounds. A comparable melting behavior was possible by compounding the two polymers as powders with similar small sized particle. The controlling of the process sensitivity was achievable, mainly, by diminishing the melt resistance to flow, via formulation with a flow agent. The selected compounds which had controlled miscibility, few defects and natural color were shaped, with good results, as filaments with silky and smooth surface. These filaments were compatible with 3D printing because proved to have the ovality and the diameter tolerance in the accepted limits in the fields.

Results of experimental studies of deliquefaction of excess activated sludge from municipal wastewater treatment facilities in chamber-membrane filter presses were presented. To condition the sludge, fly ash from thermal power plants was added as a mineral additive. Experimental studies have shown high efficiency of deliquefaction of the excess activated sludge with addition of fly ash. Increase in the dose of fly ash has led to an overall increase in filtration capacity and a decrease in moisture content in the filter cake. It was found that in the case of adding fly ash in an amount of 2 wt. % of the initial sludge, deliquefaction efficiency did not increase significantly. In this case, filtering time was reduced only by 15 % and specific capacity increased by 12 %. In the case of increasing the proportion of fly ash to 6 wt. % of initial sludge, a more intensive acceleration of the process was observed. Filtering duration was reduced from 100 to 10 min, specific capacity increased from 87 to 400 l/m2∙hr.Experimental studies have shown that addition of fly ash to sediments of municipal wastewater treatment facilities as a mineral component provides the possibility of deliquefaction of the suspensions obtained using a chamber-membrane filter press. With optimal doses of 4–5 wt. % of the mass of initial sludge, filter capacity is expected to be 350–400 l/m2∙hr. The resulting filter cake had moisture content of about 60 %, a dense, dry structure making it possible to transport it in bulk., Наведені результати експериментальних досліджень зневоднення надлишкового активного мулу з комунальних очисних споруд на камерно-мембранних фільтр-пресах. Для кондиціонування осаду було здійснено додавання золи виносу теплової електростанції у якості мінеральної добавки. Експериментальні дослідження показали високу ефективність зневоднення надлишкового активного мулу з додавання золи виносу. Збільшення дози золи виносу приводить до загального збільшення продуктивності фільтрування та зниженню вологості фільтраційного осаду (кеку). Було встановлено, що у разі додавання золи виносу у кількості 2 % від маси вихідного осаду ефективність зневоднення збільшується не суттєво. У цьому випадку тривалість фільтрування зменшується тільки на 15 %, а питома продуктивність збільшується на 12 %. У разі збільшення долі золи виносу до 6 % від маси вихідного осаду спостерігається більш інтенсивне прискорення процесу. Тривалість фільтрування скоротилася з 100 до 10 хвилин, питома тривалість збільшується з 87 до 400 літрів з квадратного метру за годину. Проведені експериментальні дослідження показали, що додавання золи виносу до осадів комунальних очисних споруд водовідведення в якості мінеральної складової забезпечує можливість зневоднення отриманих суспензій за допомогою камерно-мембранного фільтр-преса. При оптимальних дозах 4–5 % від маси вихідного осаду, прогнозована продуктивність очікується на рівні 350–400 л/м2 на годину. Одержаний фільтраційний осад має власну вологість близько 60 %, щільну, суху структуру, що забезпечує можливість його транспортування в насипному вигляді, Приведены результаты экспериментальных исследований обезвоживания избыточного активного ила из коммунальных очистных сооружений на камерно-мембранных фильтр-прессах. Для кондиционирования осадка было выполнено добавление золы уноса тепловой электростанции в качестве минеральной добавки. Экспериментальные исследования показали высокую эффективность обезвоживания избыточного активного ила с добавлением золы уноса. Увеличение дозы золы уноса приводит к общему увеличению производительности фильтрации и снижению влажности фильтрационного осадка (кека). Было установлено, что в случае добавления золы уноса в количестве 2 % от массы исходного осадка эффективность обезвоживания увеличивается не существенно. В этом случае продолжительность фильтрования уменьшается только на 15 %, а удельная производительность увеличивается на 12 %. В случае увеличения доли золы уноса до 6 % от массы исходного осадка наблюдается более интенсивное ускорение процесса. Продолжительность фильтрования сократилось со 100 до 10 минут, удельная продолжительность увеличивается с 87 до 400 литров с квадратного метра в час. Проведенные экспериментальные исследования показали, что добавление золы уноса к осадкам коммунальных очистных сооружений водоотведения в качестве минеральной составляющей обеспечивает возможность обезвоживания полученных суспензий с помощью камерно-мембранного фильтр-пресса. При оптимальных дозах 4–5 % от массы исходного осадка, прогнозируемая производительность ожидается на уровне 350–400 л/м2 в час. Полученный фильтрационный осадок имеет собственную влажность около 60 %, плотную, сухую структуру, обеспечивающую возможность его транспортировки в насыпном виде

Food waste (FW) has a high potential for use in biological processes such as anaerobic digestion (AD), especially due to its high content of biodegradable organic matter. To inoculate the reactors, sludge is usually used. The sludge should ideally have good sedimentation and specific methanogenic activity (SMA), which is typical for granular sludge. However, in a Latin American context, the most available and accessible sludges are flocculants with low sedimentation and SMA. Applying technological surveillance between 1975 and 2017, using multicriteria analysis techniques such as analytical hierarchy process (AHP), and consulting with international and national experts, we observed that there were few studies, compared to published studies on the substrates that focused on improving inoculum quality through conditioning to improve its characteristics and maximize methane production. The inoculum-conditioning methodologies identified were grouped into five categories, being the main strategy the addition of nutrients followed by anaerobic digestion with an easily degradable substrate. However, extension of technological surveillance is recommended by incorporating the results published from significant events in the field of anaerobic digestion, such as the Latin American Workshop and Symposium on Anaerobic Digestion and the World Congress on Anaerobic Digestion. RESUMEN Los residuos de alimentos (RA) presentan un alto potencial de aprovechamiento mediante procesos biológicos como la digestión anaerobia (DA), especialmente por su alto contenido de materia orgánica biodegradable. Para inocular los reactores, en general se emplean lodos que deben presentar buena sedimentabilidad y actividad metanogénica específica (AME), típico en lodos granulares. Sin embargo, los de mayor disponibilidad y accesibilidad en el contexto latinoamericano, son lodos floculentos de baja sedimentabilidad y AME. Aplicando vigilancia tecnológica desde 1975 hasta 2017, se evidenció escasa literatura enfocada a mejorar la calidad del inóculo mediante acondicionamientos para mejorar sus características y maximizar la producción de metano, en comparación con los estudios publicados sobre el sustrato. Se identificaron diferentes metodologías de acondicionamiento de inóculos, las cuales se agruparon en cinco categorías y mediante la aplicación de técnicas de análisis multicriterio como el proceso de análisis jerárquico (AHP) y con consulta a expertos internacionales y nacionales. Se identificaron las técnicas más utilizadas, siendo las principales, la adición de nutrientes seguida por la digestión anaerobia con un sustrato de fácil degradación. Sin embargo, se recomienda complementar la vigilancia tecnológica, incorporando los resultados publicados en eventos de gran importancia en el campo de la DA como el Seminario-Taller latinoamericano y el Congreso Mundial de Digestión Anaerobia.

Background and purpose Women are overrepresented in post-traumatic stress disorder (PTSD), a mental disorder characterised by ineffective inhibition of fear. The use of male animals dominates preclinical studies, which may contribute to a lack of understanding as to why this disparity exists. Thus, the current study explores sex differences in three mouse models of fear inhibition. Experimental approach All experiments tested male and female C57Bl/6J mice. Experiment 1 employed two fear conditioning protocols, in which tones were paired with footshocks of differing intensity (moderate or intense). Fear recall and extinction were tested subsequently. In Experiment 2, safety learning was investigated. Tones were explicitly unpaired with footshocks during safety conditioning. Recall of safety learning was tested 24 hr later. Experiment 3 assessed a model of fear-safety discrimination. Cued stimuli were paired or never paired with footshocks during fear and safety conditioning, respectively. Discrimination between stimuli was assessed 24 hr later. Key results In fear extinction, males, compared to females, responded with greater fear in sessions most proximal to conditioning but subsequently showed a more rapid fear extinction over time. Sex differences were not observed during safety learning. During fear-safety discrimination, both males and females discriminated between stimuli; however, males revealed a greater level of freezing to stimuli. Conclusion and implications The current study provides evidence that sex differences influence fear but not safety-based behaviour in C57Bl/6J mice. These findings indicate that processing of fear, but not safety, may play a greater role in sex differences observed for PTSD. Linked articles This article is part of a themed section on The Importance of Sex Differences in Pharmacology Research. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.21/issuetoc.

Not the type of the procedure (verbal suggestion or conditioning), but the direction of the last-used procedure shapes pain-related expectancies and determines placebo effects., In most experimental studies in which verbal suggestion and classical conditioning are implemented together to induce placebo effects, the former precedes the latter. In naturally occurring situations, however, the information concerning pain does not always precede but often follows the pain experience. Moreover, this information is not always congruent with experience. This study investigates whether the chronology of verbal suggestion and conditioning, as well as their congruence, affects placebo hypoalgesia and nocebo hyperalgesia. The effects induced in 15 groups were compared. The participants in 8 experimental groups were presented with verbal suggestions that were either congruent or incongruent with classical conditioning. The verbal suggestions were provided either before or after conditioning. In 2 other experimental groups, placebo conditioning or nocebo conditioning was implemented without any verbal suggestion; in 2 groups, verbal suggestion of hypoalgesia or hyperalgesia without conditioning was applied. The control groups without any suggestions or conditioning were also included. Placebo hypoalgesia induced by congruent procedures was significantly stronger when the suggestion of hypoalgesia preceded rather than followed conditioning. The order of the congruent procedures did not affect the magnitude of nocebo hyperalgesia. In the groups in which incongruent procedures were implemented, placebo hypoalgesia or nocebo hyperalgesia was in line with the direction of the last-used procedure, regardless of whether it was conditioning or verbal suggestion. The results show that not the type of the procedure (verbal suggestion or conditioning), but the direction of the last-used procedure shapes pain-related expectancies and determines placebo effects.

Large amounts of intergrowth and harmful impurities are present in fine raw coal, and the direct use of these can lead to the serious air pollution and solid waste. On the other hand, these impurities cover the surface of raw coal, resulting in the low hydrophobicity and floatability, which make it difficult to float. In this paper, a new method using impact flow conditioning pulp to enhance coal flotation was proposed, and the impact velocity of the conditioning pulp was optimized, thereby enhancing the flotation and cleaner production of coal. The enhancement mechanism of the impact flow conditioning pulp was investigated via measurements of SEM-EDS, adsorption, contact angle, and induction time. The conditioning-flotation experiments were performed to reveal the effect of the impact flow conditioning pulp with different impact velocities on coal flotation. The SEM-EDS analysis confirmed that the impact flow conditioning pulp could remove the coating covering the coal surface and improve the separation performance of coal from gangue. Furthermore, the impact flow conditioning pulp could significantly enhance the adsorption performance, hydrophobicity, and floatability of coal. The flotation results illustrated that the preconditioning using impact flow conditioning pulp improved the flotation efficiency of the coal, and an optimum ultimate combustible recovery of 92.86% was obtained at an impact velocity of 4 m/s.

At present, wastewater and sludge management departments are in urgent of the sludge deep-dewatering technique, which can substantially reduce sludge volume, enhance sludge calorific value and save costs. Ozonation pre-oxidation and chitosan (CT) re-flocculation conditioning have been verified to be an efficacious and environmental-friendly approach to realize sludge deep-dewatering. This paper focused on the novel insights into sludge properties under ozonation and CT conditioning. With 60 mg/gTS O3 and 20 mg/gTS CT, the water content of the conditioned sludge cake satisfied the deep-dewatering level (

Dewatering and drying is one of the important parts in municipal sludge treatment and disposal. In this paper, the sludge rapid dewatering process was studied and put into simulation in sewage treatment plant in pilot scale. The advantages of the two processes of “gravity concentration + conditioning press” and “mechanical concentration + conditioning press” were compared, and the formulation of conditioning reagent was selected and optimized. Compared with gravity concentration, mechanical concentration efficiency is higher. Adding the filtering reagent B had the advantages of high dry-base treatment efficiency, neutral pH and low moisture content after dewatering, which met the requirements of moisture content and pH for subsequent aerobic composting. Finally, the stability of this process and its system were further tested verified in practical production.

Sludge dewatering is necessary to reduce the volume of sludge for cost-effective transport and ultimate disposal. In this study, a novel combined chemical conditioning process was proposed to improve sludge dewatering performance in which sludge flocs were destructed by sodium dichloroisocyanurate (DCCNa) and re-flocculated by Al2(SO4)3 and the mechanism was elucidated. The results showed that sludge capillary suction time (CST) dropped to 15.4 s and moisture content of dewatered sludge cake (Mc) deceased to 71.01% respectively, after the application of combined conditioning with the optimal dosage of 200 mg DCCNa/g dry solids (DS) and 80 mg Al2(SO4)3/g DS. With chemical conditioning, sludge physicochemical properties were greatly changed. With the DCCNa application, the percentage of low-molecular-weight substances in soluble extracellular polymeric substances (S-EPS) increased. Also, the sludge zeta potential dropped from −16.85 mV to −25.45 mV and the median particle size (D50) decreased from 54.1 μm to 51.6 μm. However, the subsequent conditioning by Al2(SO4)3 dosing not only led to an increment of 18% in the portion of macromolecules in S-EPS, but also increased the zeta potential and D50 to −10.74 mV and 53.2 μm, respectively. The bound water content in sludge declined from 2.92 g/g DS to 1.98 g/g DS after combined conditioning. We concluded that DCCNa disintegrated the sludge flocs and microbial cells leading to the release of bound water, fine particles and organic substances with negative charge, and the fine colloidal particles can be flocculated into large dense aggregations with the dosing of Al2(SO4)3. In summary, the proposed combined conditioning provided a highly effective and environmental friendly approach to improve the sludge dewatering performance.

Natural light is regarded as a key regulator of biological systems and typically serves as a Zeitgeber for biological rhythms. As a natural abiotic factor, it is recognized to regulate multiple behavioral and physiological processes in animals. Disruption of the natural light regime due to light pollution may result in significant effects on animal learning and memory development. Here, we investigated whether sensitivity to various photoperiods or light intensities had an impact on intermediate-term memory (ITM) and long-term memory (LTM) formation in the pond snail Lymnaea stagnalis. We also investigated the change in the gene expression level of molluscan insulin-related peptide II (MIP II) is response to the given light treatments. The results show that the best light condition for proper LTM formation is exposure to a short day (8 h light) and low light intensity (1 and 10 lx). Moreover, the more extreme light conditions (16 h and 24 h light) prevent the formation of both ITM and LTM. We found no change in MIP II expression in any of the light treatments, which may indicate that MIP II is not directly involved in the operant conditioning used here, even though it is known to be involved in learning. The finding that snails did not learn in complete darkness indicates that light is a necessary factor for proper learning and memory formation. Furthermore, dim light enhances both ITM and LTM formation, which suggests that there is an optimum since both no light and too bright light prevented learning and memory. Our findings suggest that the upsurge of artificial day length and/or night light intensity may also negatively impact memory consolidation in the wild.

Dewatering is of paramount step in sludge management, and conditioning with coagulant is considered as the commonest way to improve the sludge dewaterability. Sludge disintegration process was examined through Ultrasound (US) to strip the water from the sludge flocs and accordingly four coagulants: aluminium sulphate (Alum), iron (III) chloride (FeCl3), cationic polyacrylamide (CPAM) and combined ferric chloride and lime (CC) with optimum dosages were employed to improve the sludge dewaterability in terms of capillary suction time (CST), specific resistance to filtration (SRF) and moisture content (MC). The ultrasonic sludge disintegration with 1 min exposure with an energy dosage of 700 kJ/kg TS realises the best sludge dewatering efficiency. In addition, the effects of CPAM and CC conditioning on sludge dewaterability were higher compared with two other conditioners. The combined US-CPAM and US-CC with optimum dosages 8 and 101 mg/kg DS significantly improved sludge dewaterability parameters (MC: 68.50%, SRF: 1.03 × 1010 m/kg and CST: 31.82 s) and (MC: 72%, SRF: 1.08 × 1010 m/kg and CST: 31.82 s) compared with when conditioning experiments were performed alone. Scanning electron microscopy (SEM) images showed that the combined US-CPAM and US-CC conditioning formed a more porous structure and low compressible sludge filter cake which are desired to sludge dewatering. Therefore, the ultrasonic-assisted conditioning with CPAM and combined coagulant (lime + Ferric chloride) could significantly improve the sludge dewaterability indices.

In this study, for the first time, the occurrence mechanism of anaerobically digested sludge conditioning for dewatering process based on Electrochemical-Fenton technology was investigated and the optimum condition has been determined to employ a lab-scale reactor. Due to the results of current studies using electrochemical and Fenton methods, a comparative economic-technical investigation has been provided accordingly. The results showed that under optimum operational condition by utilizing Electrochemical-Fenton process e.g. H2O2 = 25 mg/g DS (dry solid), Fe2+ = 15 mg/g DS, retention time = 20 min, electrolysis voltage = 11 V, the specific resistance to filterability (SRF) and time to filter (TTF) parameters reduction equal to 93.8% and 75.9% respectively. The occurrence mechanism of the sludge conditioning was determined by evaluation of extracellular polymeric substances (EPS), particle size distribution, zeta potential and bound water tests. The dry solids concentration of the conditioned sludge by Electrochemical-Fenton process was increased from 2.3% to 41% by dewatering employing filter press system. Furthermore, the estimated cost of conditioning using this method is 41.82 USD$/t DS, which is less than other investigated methods e.g. traditional Fenton process. It can be concluded that the results reached in this comprehensive and comparative study could be a suitable basis for further investigations regarding utilization of novel electrochemical advanced oxidation technologies for efficient sludge conditioning and dewatering purposes.

Two new freezing treatment methods (partial ultrasonic freezing and combined ultrasonic freezing) were examined for their effectiveness on both solubilisation of organic matter and enhancement of sewage sludge conditioning. The treatment efficiency of the new freezing methods was compared with that of conventional freezing. The test results revealed that the capacity of the two new freezing methods on solubilisation of sludge organic matter was comparable to that of conventional freezing with three to five freezing and thawing cycles. About five to seven times increase in sample soluble chemical oxygen demand and soluble protein concentrations were observed after treatment using the three different freezing methods. Significant improvement in sludge conditioning was also achieved; more than 80% reduction in settled sludge volume was noted in the freezing-treated samples. Overall, all freezing techniques examined showed great potential as effective treatment methods that could not only enhance sludge conditioning but also solubilise organic matter.

The conditioning stage is a key parameter for enhancing the efficiency of sludge dewatering. However, the choice of the conditioning procedure (type of flocculant, dosage, mixing conditions) remains a current difficulty. A new index (called drainage index) was introduced to optimize conditioning parameters specifically for sludge thickening on draining table and by extension for sludge dewatering in belt filter press. This easy and quick to measure index was tested via lab-scale drainage experiments. Drainage performance was measured in terms of particles capture rate, final sludge dryness and drainage kinetics. The drainage index allowed to select optimal flocculation conditions prior to gravity drainage. Its relevance to select flocculation conditions insuring a good sludge compression was also demonstrated (except for the polymer selection) from tests carried out in lab-scale filtration–compression device.

Coagulation or flocculation is often individually used or in hybrid conditioning with other preconditioning for sludge dewatering. However, combined conditioning with coagulants and flocculants for sludge dewatering is rarely reported. In this study, dewatering performances of sludge with individual use of poly(aluminum chloride) (PACl; as the coagulant) and a biopolymer named “BF-ADSW” (as the flocculant) were investigated, and the feasibility of applying the coagulation–flocculation process using PACl and BF-ADSW for sludge dewatering and the related mechanism were explored. BF-ADSW was harvested from anaerobically digested swine wastewater (ADSW), and its yield was 2.98 g/L, meaning that 2.98 g of BF-ADSW can be harvested from 1 L of ADSW. After conditioning by PACl with a dose of 10% dry solids (DS), the sludge moisture content and settled volume after 30 min were decreased from the raw values of 98.5% and 96.1% to 80.8% and 74.2%, respectively, which were further decreased to 62.3% and 49.2% after fu...

When one becomes ill after consuming a meal, there is a propensity to target a particular taste as the cause of the illness. The qualities of the taste most likely targeted include more novel, less preferred, and higher protein content. This association between a particular taste and illness is a form of learning that is termed conditioned taste aversion (CTA). A consequence of the learned association is that the taste will become aversive. When experiencing the taste again, individuals will show aversive reactions such as expressions of loathing, will experience mimicked illness sensations such as nausea, and subsequently, will avoid further exposure to the taste. The ability to acquire CTA occurs across species and across ages within a species. In the rat animal model, however, age differences exist in the capability of acquiring CTAs when increasingly longer intervals are imposed between consumption of a novel sweet solution and onset of illness. Pups have a decreased ability compared to young adults while aged rats have an increased ability. Evidence suggests that the failure of pups to acquire CTA at longer intervals is due to an immature retrieval mechanism and the facilitated ability of aged rats is due to a compromised clock mechanism that tracks the passage of time. Learned taste-illness association serves the critical function of informing individuals of the toxic nature of certain foods, thus preventing further illness and potentially death. Additionally, it contributes to the hypophagia observed during cancer chemotherapy and may contribute to the hypophagia found while suffering from bacterial infection, chronic medical conditions such as cancer, and restrictive food intake disorders such as anorexia nervosa. Keywords: Age differences, Aversion reactions, Avoidance, Hypophagia, Illness sensations