Degree Of Disintegration Research Articles

The Effect of Thermomechanical Pretreatment on the Structure and Properties of Lignin-Rich Plant Biomass.

The cooperative thermomechanical properties of plant-derived polymers have been studied insufficiently, although this feedstock has a very high potential. In the present paper, we analyzed the changes in the structure and physicochemical properties of lignin-rich biomass induced by thermomechanical pretreatment. Low-temperature treatment allows one to retain the original supramolecular structure of the cell walls, while an appreciably high disintegration degree is reached. This increases the reactivity of the material in the subsequent heterogeneous reactions. Mechanical pretreatment at medium temperatures (10 °C), when almost all cell wall polymers except for low-molecular-weight lignin are in the glassy state, enhances the mobility of cell wall polymers and causes sufficient cellulose disordering, while the specific surface area is not significantly increased. High-temperature pretreatment of reed biomass is accompanied by pore formation and lignin release from the cell wall structure, which opens up new prospects for using this biomass as a matrix to produce core–shell-structured sorbents of heavy metals. The energy consumed by mechanochemical equipment for the activation of reed biomass was determined.

Comparison of two advanced anaerobic digestions of sewage sludge with high-temperature thermal pretreatment and low-temperature thermal-alkaline pretreatment

Semi-continuous experiments were conducted to compare the performances and energy efficiencies of two advanced anaerobic digestions (AAD) of sewage sludge with high-temperature thermal pretreatment (HTTP, 160 ± 1 °C and 0.55 MPa for 30 min) and low-temperature thermal-alkaline pretreatment (LTTAP, 60 ± 1 °C and pH 12.0 ± 0.1 for 30 min), which had similar sludge disintegration degree (9.44–9.48%). At the steady period of a SRT 20 d, the two AAD had similar methane production (150.22 ± 9.55 ml/L/d and 151.02 ± 12.56 ml/L/d) and organic matter removals (22.54 ± 2.84% and 23.15 ± 2.46% for volatile solids-VS). The results of high-throughput sequencing showed that the methanogenic pathways of the two AAD were strictly hydrogenotrophic (AAD with HTTP) and hydrogenotrophic/acetoclastic methanogenesis (AAD with LTTAP), respectively. The energy balance analysis suggested that the AAD with LTTAP was superior to that with HTTP because the former had a higher energy efficiency (1.610) than the latter (1.358).

Барьерность городской среды и ее количественная оценка (на примере Москвы)

The article is devoted to the analysis of city boundaries-barriers in Moscow. City barrier is considered as one of the types of boundary between city nodal areas. Such boundary is rigid, clear, and quasilinear and it exists for a long time (decades or more). The barrier function of the urban environment is the degree of city disintegration into relatively loosely connected areas with internal integrity. There are three types of urban barriers’ genesis – automobile, rail, and water. Military, forested, industrial and fenced private areas are not considered because they do not divide city regions (social, economic, political etc.), but only separate selected areas from the urban environment (they are independent regions). There are barriers with maximum and minimum permeability of borders for each city. The boundaries’ permeability in this case refers to the possibility and degree of trespassing the barrier. The author names the city barrier with the maximum permeability “barrierstandard”, and the barrier with minimum permeability “barrier-filter”. Comparison of “barrier-standard” and “barrier-filter” demonstrates territorial differences within the city. Comparison of different types of barriers with the “barrier-standard” and the “barrier-filter” allows to measure representative permeability value in comparison with maximum and minimum values.

Trgovina ljudima u oružanim sukobima

Armed conflicts disrupt political, legal and social peace and create an environment conducive to human trafficking, as another dimension of violence and brutality. The direct connection between these two phenomena arises from the hostility of the parties in the conflict and encompasses the areas affected by the conflict, and the indirect connection is manifested in the area outside the conflict, in refugee camps or on migration routes. The most significant influencing factors on human trafficking, in addition to those operating in peace (push and pull factors), are the weakening of state institutions and the collapse of the rule of law, population displacement, poverty, population fragmentation and family collapse. The increased scope of migration (internal and cross-border) has a significant impact on human trafficking. Unsafe living conditions and various forms of violence complicate push and pull factors, which initiate mass migrations.People on migrant routes are very vulnerable and exposed to organized criminal groups and terrorist groups, with the risk of becoming victims of human trafficking or other forms of violence. The characteristic types of exploitation in armed conflict are sexual exploitation, sexual slavery, forced labor, organ removal, and recruitment to engage in conflict, often involving children. The main actors in human trafficking are armed and criminal groups. By trafficking, armed groups carry out a profit for their own financing, strengthen military capabilities and create fear among the population to control the territory. Sexual and other violence is also used as part of broader strategies to expel undesirable groups and exploit disputed land and other resources. Trafficking in children is mainly a consequence of the economic difficulties experienced by their families. Children are usually exploited in areas of work that do not require special expertise, such as agricultural work, street sales, etc., but are also used in armed conflicts as suicide bombers or human shields. The use of children as armed fighters is widely documented in sub-Saharan and central Africa, the Middle East, and other regions of Asia. In addition to various types of violence and general suffering of the population, human trafficking in armed conflicts has a particularly negative impact on human rights violations, when the exploitation of victims can be transformed into more serious crimes. Suitable conditions for human trafficking persist after the conclusion of a formal truce or peace. The lack of the legal system's and institution's functioning results in impunity for perpetrators of criminal acts and the growth of organized crime, and thus human trafficking. The persistently high degree of disintegration, which has affected human trafficking in armed conflicts, as well as the new difficult economic circumstances, further increase the risk of human trafficking. Particularly tempting targets for traffickers are displaced persons and refugees returning from camps or war camps. Human trafficking in the post-conflict period, although mostly indirectly, is also affected by the presence of various peace and other missions, especially on trafficking for sexual and labor exploitation.

Enhanced biodegradability of dairy sludge by microwave assisted alkaline and acidic pre-treatments

Considering the rapid, volumetric and selective heating effects of microwaves the microwave assisted chemical methods could provide appropriate alternatives for conventional thermal methods in sludge processing. Microwave irradiation alone is suitable to accelerate the hydrolysis stage of anaerobic decomposition of sludge resulted in accelerated biogas production rate and in higher biogas yield. Alkaline pre-treatments increase the organic matter solubility and suitable for disintegration of sludge particles. In some study are concluded that acidic conditions help the disintegration of waste activated sludge and assist in the solubilisation of carbohydrates and proteins which led to increased higher biogas production, as well. Beside the promising results related to effects of microwave pre-treatments on anaerobic digestion of sludge there are very few reports on the investigation of combined acidic/alkali-microwave pre-treatment method for food industry originated sludge. Hence, our study focused on the examination of the effects of combined microwave-alkali and microwave-acidic pre-treatment on aerobic and anaerobic biodegradability of sludge produced in dairy industry
 Our experimental results verified, that microwave irradiation with alkaline dosage improve the solubility of organic matters in the pH range of 8-12. But enhancement of disintegration was not correlated linearly with biodegradability. During pre-treatment stage, applying pH over 10, the aerobic biodegradability show decreasing tendency. Applying of acidic condition during microwave irradiation resulted in lower disintegration degree than obtained for microwave-alkaline sludge pre-treatment method. But with microwave assisted acidic pre-treatments a higher aerobic biodegradability could be achieved than with alkaline dosage. In microwave pre-treatments acidic condition was preferable to increase the shorter aerobic biodegradability; the alkaline condition was favourable to intensify the anaerobic digestion process.

Sewage sludge, pharmaceuticals and composting

Enzymatic polymerization has a large potential as an environmentally friendly synthetic process. Lipase is a renewable catalyst with high catalytic activity from which it is possible to develop a versatile method for the production of sustainable polyurethanes. In this work oligomeric PCL-diol was synthesized using biocatalysis with immobilized Yarrowia lipolytica lipase (YLL) and diethyleneglycol as initiator. Then, two different linear polyurethanes were prepared. One was obtained directly from the previous synthesized PCL-diol and hexamethylene diisocyanate, named PU, and the other one has been obtained by incorporating l-lysine amino acid as end group (lys-PU). PU and lys-PU disintegration under composting conditions was evaluated. The influence of the presence of l-lysine on the disintegration performance of PU was studied by evaluating the disintegration degree, monitoring the weight loss. Structural and morphological changes were followed by Fourier transformed infrared spectroscopy (FTIR) and by scanning electron microscopy (SEM).

ANAEROBIC BIODEGRADABILITY ENHANCEMENT OF MEAT PROCESSING WASTEWATER SLUDGE BY FENTON PROCESS

In this study, an advanced oxidation process of Fenton Process was applied to meat prosessing wastewater sludge for the purpose of sludge disintegration before anaerobic digestion. Fenton Process was applied to the meat processing wastewater sludge samples were taken from a treatment plant located in Denizli, Turkey. In the first stage of the study, experiments were carried out to optimize the process conditions in terms of disintegration using Box-Wilson Statistical Design. Ferrous iron and hydrogen peroxide concentrations were chosen as process variable and disintegration degree parameter based on soluble chemical oxygen demand calculations used as process response. 13% of disintegration degree was obtained at 90 gH2O2/ kg Dried Solids and 3 g Fe(III)/kg Dried Solids. After optimization studies for disintegration, sludge digestion studies were carried out using Biochemical Methane Potential (BMP) Test. BMP test results showed that Fenton Process can be used as a sludge disintegration purpose and application of Fenton Process before anaerobic digestion causes 33% higher methane gas production comparing the non-pretreated sludge.

ANAEROBIC BIODEGRADABILITY ENHANCEMENT OF MEAT PROCESSING WASTEWATER SLUDGE BY FENTON PROCESS

In this study, an advanced oxidation process of Fenton Process was applied to meat prosessing wastewater sludge for the purpose of sludge disintegration before anaerobic digestion. Fenton Process was applied to the meat processing wastewater sludge samples were taken from a treatment plant located in Denizli, Turkey. In the first stage of the study, experiments were carried out to optimize the process conditions in terms of disintegration using Box-Wilson Statistical Design. Ferrous iron and hydrogen peroxide concentrations were chosen as process variable and disintegration degree parameter based on soluble chemical oxygen demand calculations used as process response. 13% of disintegration degree was obtained at 90 gH2O2/ kg Dried Solids and 3 g Fe(III)/kg Dried Solids. After optimization studies for disintegration, sludge digestion studies were carried out using Biochemical Methane Potential (BMP) Test. BMP test results showed that Fenton Process can be used as a sludge disintegration purpose and application of Fenton Process before anaerobic digestion causes 33% higher methane gas production comparing the non-pretreated sludge.

United States Democratic Party and the 2020 Presidential Election: The Main Candidates, Topics and Features of the Election Rhetoric

Introduction. The article is of relevance due to the beginning of the active phase of the race for the right to become the Democratic Party’s nominee for the 2020 United States presidential election. The range of issues, topics and features of the election rhetoric of the Democrats will largely determine the outcome of the 2020 election and therefore will influence the subsequent development of the United States. The objective of the study is to analyze the political rhetoric of the major Democratic Party presidential candidates and the political trends among the ranks of the Democrats, taking place against the backdrop of the election campaign. Materials and Methods. The study was based on the methods of empirical analysis, such as description, synthesis, analogy, classification, and comparison, which made it possible to consider the main characteristics and topics of the political rhetoric of members of the United States Democratic Party. Publications in the media, recordings of public speeches of the Democratic Party members, statistics, sociological polls, and research by Russian and foreign scientists were used as the materials for the study. Results. The author has identified the main topics and features of the election rhetoric of the Democratic Party presidential candidates. Issues of public health, education, and ecology have become central topics for the potential Democratic presidential candidates, which is largely due to a significant shift to the left and the role of the left-wing Democrats in the electoral process. The study has revealed a significant degree of political disintegration in the Democratic Party. The major challenge the Democrats are faced with today is to nominate a candidate who will be able to fight back the energetic rhetoric of Donald Trump, retain the traditional electorate of the Democratic Party, and attract new supporters. Discussion and Conclusion. The research results provide an insight into the processes taking place in the Democratic Party at the stage of nominating the Democratic presidential candidate. The data presented in the article will be useful to researchers interested in the history and politics of the United States. The study conducted makes it possible to better understand the current trends in American domestic policies, which largely determine the state of affairs in international relations.

A study of solubilization of sewage sludge by hydrothermal treatment

The use of activated sludge process for biological treatment of domestic and industrial wastewaters generates large amounts of sewage sludge, which is regarded as problematic biowaste. Conventional waste treatment methods such as landfilling and ocean pumping have been used to dispose the unwanted sludge, but this practice is no longer recommended due to serious secondary pollution and strict environmental regulations. Hydrothermal treatment represents a promising alternative that has attracted attention in recent years. In this study, batch experiments of hydrothermal treatment of domestic sewage sludge were conducted under varying conditions (temperature of 150–300 °C, reaction time of 0.5–3.0 h, and sludge concentration of 5–30 g/L). A statistical study of the responses, including disintegration degree and concentration of dissolved compounds, was performed using a response surface methodology. Optimal conditions for hydrothermal treatment of sewage sludge were obtained through mathematical modeling.

Optimization of Energy Consumption of the Ultrasonic Pretreatment on Sludge Disintegration

Anaerobic digestion is a widely used method to treat sludge, while its application was limited by its ineffective hydrolysis rate. Ultrasonic pretreatment could enhance the hydrolysis rate of sludge, while the development of ultrasonic had been restricted by the high energy consumption, it was necessary to optimize the energy consumption. Disintegration degree was analysed by the particle size, SCOD increase, soluble proteins and carbohydrates of the sludge before the after the ultrasonic pretreatment, the relationship between the specific energy input and the disintegration degree was discussed. The results showed that after ultrasonic disintegration, the concentration of SCOD, soluble protein and carbohydrate increased with the increase of ultrasonic time and ultrasonic power. High power ultrasonic could effectively disintegrate sludge in a short disintegration time, while low power ultrasonic needed a long time to disintegrate sludge. And under the same specific energy consumption conditions, the combination of lower power density and longer ultrasonic time could obtain better disintegration degree than the combination of higher power density and shorter time. It was confirmed that the energy utilization efficiency of the lower power density and the longer time combination was higher.

A combined method of hydrodynamic cavitation and alkaline treatment for waste-activated sludge solubilization; N/P recovery from anaerobic granular sludge

Waste-activated sludge (WAS) is typically processed very slowly and only to a certain extent in anaerobic digestion (AD), typically necessitating pre-treatment. In this study, we developed a new and powerful way of pre-treating WAS, which is a combination of hydrodynamic cavitation (HC) and alkaline treatment, and examined it for its efficacy. The combined treatment yielded the highest disintegration degree (DD) of 48.4%, while HC alone produced only 11.9% of DD and alkaline alone did 16.2%. The pre-treated sludge led to much enhanced methane production compared with the untreated one; 80.7 ml/g CODadded was the largest amount of CH4 obtained with the pre-treated sludge, while 37.3 ml/g CODadded with the untreated one. The distinctive efficacy of the HC was further exploited to remove nutrients from anaerobic granular sludge (AGS) in a beneficial way: namely, the HC-mediated recovery of N/P by way of struvite precipitation. The highest phosphate removal was found at pH 10 with HC, which was more than twice the value of a simple stirring (63 mg PO43−/L by simple stirring versus 150 mg PO43−/L by HC). It appeared that HC is indeed a sure option for WAS pre- and post-treatment to improve biodegradability and nutrient recovery, respectively.

Effect of toilet tissue Paper on residential sewerage-line clogging

Toilet paper is widely used in residences. The low biodegradability of toilet paper’s pulp fibers can cause residence sewer lines to clog, which may be due to some additives or the presence of nonwoven fiber products. In this study, the disintegration rate of toilet paper was compared against various physical factors of the toilet paper sheet. The samples were disintegrated in water at varying pH levels. In the manufacturing of toilet paper, there must be a balance between the desired softness and the necessary wet strength. Twelve commonly used brands of toilet paper were purchased locally. Physical factors of toilet paper samples such as degree of polymerization, thickness, grammage, and softness were determined. The samples were evaluated based on 9 variables using correlation and multivariate linear regression analyses. A strong positive relationship was found between the degree of disintegration of toilet tissue paper and its physical factors. These were the degree of polymerization, the grammage, thickness, and the softness. Additionally, the amount of polymers applied to toilet paper decreased the degree of softness and adversely affected the redispersion of fibers. Thus, this work supports the idea that toilet paper can contribute to clogging of residential sewerage lines.

Biochemical Methane Potential Tests to Evaluate Anaerobic Digestion Enhancement by Thermal Hydrolysis Pretreatment

This study evaluates the effects of thermal hydrolysis (TH) pretreatment on anaerobic digestion (AD), through results obtained by biochemical methane potential (BMP) tests under mesophilic conditions (35 °C). Thickened sludge from a wastewater treatment plant (WWTP) was thermally treated under two different temperatures (150 and 170 °C) and reaction times (30 and 60 min). Results show a significant increase in soluble COD, compared with the untreated sludge, when sludge was treated at 170 °C for 60 min. Moreover, the following BMP tests point out that TH pretreatment of sludge accelerated the AD rate and increased the biogas yield contributing to an increase in methane production, ranging between 17 and 24% compared with the raw sludge. Furthermore, the hydrolysis constant was estimated and methane production and degree of disintegration of the TH pretreated sludge were correlated, in order to deep the knowledge on the hydrolysis as the AD rate-limiting step. Further, the combined effects of TH pretreatment and AD on sludge show a reduction of total and volatile solids up to 19% and 24%, respectively.

A novel sewage sludge biochar and ferrate synergetic conditioning for enhancing sludge dewaterability

A great prospect of sewage sludge self-recycling as a conditioner supports the research. A synergetic conditioning effect and mechanism were reflected after the synergistic conditioning experiment, and the corresponding separated experiment of biochar, K2FeO4 or acid treatment on WAS. All of the biochar, K2FeO4 and acid treatment could reduce the water content of sludge cake. Biochar had good effect on WAS settleability, although the influence of the biochar dosage was weak. Similar to K2FeO4, acid treatment also could reinforce the disintegration degree effectively, but it deteriorated the filter property of WAS. In the situation of synergistic condition, owing to the strong oxidation of K2FeO4, most of the sludge flocs was disintegrated, thus the settleability and filter property of WAS were still bad, even the biochar worked as a skeleton builder. It is encouraging to find that, even without acid treatment, there is a great decline of water content of sludge cake in the situation of synergistic condition.

Waste-activated sludge disruption by dry ice: bench scale study and evaluation of heat phase transformations

The freezing process consists of dissipating heat from the product until the final temperature is lower than the temperature of crystallisation of that product. Freezing can be used for numerous applications, including for disruption of waste-activated sludge (WAS). The aim of this study was to calculate the estimated amount of heat conveyed between the solidified carbon dioxide and the WAS, in the following ratios: 0.25:1; 0.5:1; 0.75:1 and 1:1. In heat of phase transformations, dry ice sublimation, water solidification, the amount of heat transferred by other substances and heat transferred from the sludge (dry sludge) were taken into account during the process of WAS freezing. Heat changes on the surface of WAS were registered using a thermovision camera. The effectiveness of WAS disintegration was confirmed by several biochemical parameters such as soluble chemical oxygen demand (increase over 14 times), degree of disintegration (48%), proteins (increase over 5 times), carbohydrates (increase almost 7 times), RNA (increase by 2.23 mg L−1), ammonia nitrogen (increase over 23 times), phosphates (increase almost 27 times) and turbidity (increased over 7 times). It was found that dry ice pretreatment of WAS can be an intriguing alternative for the conventional methods used.

Methodologies to assess biodegradation of bioplastics during aerobic composting and anaerobic digestion: A review.

Bioplastics are emerging on the market as sustainable materials which rise to the challenge to improve the lifecycle of plastics from the perspective of the circular economy. The article aims at providing a critical insight of research studies carried out in the last 20 years on the degradation of bioplastics under aerobic composting and anaerobic digestion conditions. It mainly focuses on the various and different methodologies which have been proposed and developed to monitor the process of biodegradation of several bioplastic materials: CO2 and CH4 measurements, mass loss and disintegration degree, spectroscopy, visual analysis and scanning electron microscopy. Moreover, across the wide range of studies, the process conditions of the experimental setup, such as temperature, test duration and waste composition, often vary from author to author and in accordance with the international standard followed for the test. The different approaches, in terms of process conditions and monitoring methodologies, are pointed out in the review and highlighted to find significant correlations between the results obtained and the experimental procedures. These observed correlations allow critical considerations to be reached about the efficiency of the methodologies and the influence of the main abiotic factors on the process of biodegradation of bioplastics.

GRANULOMETRY AND ENERGY CONSUMPTION AS INDICATORS OF DISINTEGRATION EFFICIENCY IN A HAMMER MILL ADAPTED TO EXTRACTING ARROWROOT STARCH (Maranta arundinacea) IN COMPARISON TO STARCH EXTRACTION FROM CASSAVA

ABSTRACT The commercial sector of starch extraction has fully automated plants with a minimum scale of 200 ton.day–1, which extracts starch from maize and cassava in Brazil. Although these starches are commodities, the market demands starches with special properties obtained without chemical modifications. A higher-priced starch can compensate for small-scale extraction, as in the case of arrowroot starch, which would correspond to an alternative income for the producer. As a small-scale equipment was not available in Brazil, it was necessary to adapt a hammer mill for arrowroot starch extraction, which should have a performance similar to that obtained from cassava roots using industrial grinders. The degree of disintegration and energy consumption were adopted as the efficiency indexes. The hammer mill was equipped with two perforated plates. The results showed that use of an adapted hammer mill provides an average diameter of 74.64 ± 0.09 μm for perforated plate 1 (TP1) and 76.62 ± 0.06 μm for TP2; these results were equivalent to those obtained with cassava in the respective perforations which, in turn, was comparable to the degree of grinding obtained with large industrial equipment. The specific energy consumption needs for arrowroot disintegration varied from 31.47 to 48.91 kJ.kg–1, which was considered close to that calculated for large-scale industrial cassava roots grinders, reported at 37.03 kJ.kg–1.

High efficiency of excess sludge reduction and dewaterability using newly prepared alkaline ferrate pretreatment combined with anaerobic digestion

The mechanism of newly prepared alkaline ferrate (NPAF) on the process of sludge aggregates disintegration and combined with anaerobic digestion to enhance the efficiency of reduction and dewaterability of excess sludge was investigated. The results showed that under a NPAF dosage of 70 mg/g total suspended solids (TSS), the extracellular polymeric substances (EPS) structure of the sludge aggregates was disintegrated, and the sludge disintegration degree (DDSCOD) reached 22.5%. The microbial cells in the sludge aggregates were not oxidized, and the direct anaerobic digestion of pretreated sludge could realize the rapid release and degraded of organic matter in the sludge and favor enhancement of the sludge settleability and dewaterability. Compared with the original sludge, the MLVSS of the sludge treated with ferrate pretreatment combined with anaerobic digestion decreased by 40.6%. NPAF exhibited oxidation and flocculation functions rather than phosphorus removal during the pretreatment process. Compare with direct anaerobic digestion of pretreated sludge, inoculation of the raw sludge during anaerobic digestion did not accelerate the release of organic matter, but could effectively enhance the sludge dewaterability and ensure the subsequent treatment of the sludge.

Tailoring of oxidized starch's adhesion using crosslinker and adhesion promotor for the recycling of fiberboards

ABSTRACTThe growing interest in recycling waste medium density fiberboards (MDFs) is driving the development of new adhesives that provide sufficient adhesion, and allow disintegration of the waste MDFs. Described in here is the preparation of adhesives based on oxidized starch (OS) in combination with blocked‐polymeric 4‐4 diphenylmethane diisocyanate (B‐pMDI) as a crosslinker and poly(vinyl alcohol) (PVA) as an adhesion promotor for the recycling of waste MDFs. The COOH groups of OS were reacted with NCO groups of B‐pMDI to form amide linkages, and the CHO groups were reacted with OH groups of PVA through hydrogen bonding. Further, when applied as an adhesive, the OS formed ester linkages with OH of MDF fibers. As the results, MDF bonded with 1% B‐pMDI/15% PVA/OS adhesive had an internal bonding strength of 0.13 MPa, 0.01 mg L−1 of formaldehyde emission (FE), and 12% of degree of fiber disintegration. These results demonstrate that the B‐pMDI/PVA/OS adhesive is a possible alternative to the current urea–formaldehyde resins for the recycling of waste MDFs into recycled MDFs without FE. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47966.