Biochar and Sulphur Enriched Digestate: Utilization of Agriculture Associated Waste Products for Improved Soil Carbon and Nitrogen Content, Microbial Activity, and Plant Growth

A number of agriculture residues may be used either directly or after suitable treatment as amendments to improve soil quality. Such materials include biochar made of agriculture residues, digestate or elemental sulphur obtained from biogas desulphurisation. The joint use of these materials via pre-incubation may be more advantageous than only mixing prior the application to soil. In this study, digestates were mixed with amendments and incubated for 6 weeks before application to soil in a short-term pot experiment with lettuce (Lactuca sativa). The following treatments were tested: control digestate, digestate + biochar, digestate + elemental sulphur, digestate + biochar + elemental sulphur. The biochar-enriched digestate significantly increased soil microbial biomass, soil C:N, fresh above ground biomass, fresh and dry root biomass. Elemental sulphur-enriched digestate caused highest arylsulfatase and phosphatase, increased urease, microbial biomass in soil and fresh root biomass. Amendment of digestate + biochar + sulphur led to the significantly highest total soil carbon, microbial biomass, β-glucosidase, urease, and increased C:N ratio, arylsulfatase in soil and root biomass. It mitigated the adverse effect of either biochar or elemental sulphur on soil respiration. Properties of digestates were apparently affected by pre-incubation. This approach in digestate fertilizer production may contribute to sustainable farming.

Pretreatment and Bioprocess Trials in Various Reactor System on Lignocellulosic Biomass for Cellulosic Biomaterials

Pretreatment on lignocellulosic biomass prior to extraction of biomaterials, degradation of bioproduct, or production of biomaterial/bioproduct/biofuel, crucially influences the intended outcomes. The pretreatment of oil palm fronds (OPF), one of the most abundant agriculture residues in Malaysia, can be conducted based on the need of the methodology, either for small, lab, pilot, or industrial scales. In this article, examples of reactors for the pretreatment for instance microreactor (Bioshake iQ), conical shake flask, and mini-cylindrical reactor scale (fabricated) as well as the monitoring bioreactor (BlueSens Monitoring GmbH) reactor system dedicated for fermentation process using the outcome material from pretreatment process, are presented. All pretreatment trials with ionic liquid (IL) of 1-ethyl-3-methylimidazolium acetate [EMIM]Ac on OPF were conducted with a scaling-up strategy from micro-to-macro to fabricated reactors, monitoring Crystallinity Index (CrI) and Lateral Order Index (LOI). Electron beam irradiation pretreatment using 1000kGy was also tested in macroscale mode for CrI and LOI. Effectiveness of approximately 23 to 37% of CrI via microreactor experiments using 50, 70, and 90% v/v of [EMIM]Ac and at a temperature of 99oC was observed. Higher concentration of IL and temperature with nearly insignificance of solid loading of OPF in reaction liquid to the increase of the amorphous level of OPF was reported by macroscale mode in the 570-mL fabricated reactor. A short oxygen uptake rate (OUR) phase was observed in a 500-mL BlueSens shake flask with the real-time monitoring systems for 45-mL working volume, a nearly 10% of the total reactor volume for saccharification-fermentation using Escherichia coli K011 ATCC 55124 on approximately 2.22% w/v pretreated OPF from macroscale mode. Various data examples from these micro-to-macro scales including in a fabricated reactor system mode are crucially needed for further observations prior to pilot or industrial scales, needing a systematic data collection to be simulated and investigated in the future.

Status of Air Pollution over the Last Three Decades in Thimphu City, Bhutan

With an increasing human population and vehicles, air pollution in Thimphu City is growing and causing a risk to human health, properties, and ecosystems. The population of Thimphu was 79,185 in 2005 but in 2017 it surged up to 114,551. An increase in the human population has also led to the rising demands for vehicles and thus increased the vehicular emissions in the area. Additionally, the use of traditional fuels, burning of waste and agriculture residues, forest fire, and transboundary pollutants are other sources resulting in poor air quality in Thimphu City. Air pollution data from journal articles, government documents, reports from national and international organizations, and books were reviewed. Concentrations of PM10, PM2.5, SO2, NO2 were increasing over the decades. The annual average PM10 recorded in Thimphu was 28 µg/m3 in 2005, 47 µg/m3 in 2010, 43 µg/m3 in 2014, and 42 µg/m3 in 2015. Winter months were found to have higher PM10 and PM2.5 concentrations. The 24-hourly average concentrations of SO2 ranged from 0.0 to 6.9 µg/m3 and NO2 8.2-26.6 µg/m3. There is a need for comprehensive studies to identify spatial and temporal variations in the ambient concentration of the pollutants in the area. Strict enforcement of the legal frameworks is essential for the mitigation of air pollution in Thimphu City.

The current landscape fire management in Ukraine and strategy for its improvement

Recurrent wildfires in Ukraine exert severe impacts on the environment, human health and security as well as damage to private and public assets. From 2007 to 2020, the frequency of large wildfires has increased and reached a level that has not occurred previously. The period during April-October 2020 was the worst in modern Ukrainian history for the occurrence of catastrophic fires, e.g. in the Chernobyl Exclusion Zone (67 000 ha), Zhytomyr oblast (43 000 ha), Lugansk oblast (35 000 ha) and Kharkiv oblast (8 000 ha). In Ukraine there is the additional problem of open burning, mainly burning agriculture residues, which covers two million hectares (ha) annually. State forestry enterprises who are responsible for the management of 71% of the Ukrainian forests (7.6 million ha)and agricultural holdings are also responsible for the management of 41.3 million ha of croplands. The remaining forest users manage forest areas of 3.1 million ha within reserves and national nature parks. This article presents a brief overview of the problem of forest fires as well as of fires in other landscapes in Ukraine, and includes a critical reviews of the current wildfire management system and a description of the main features of the national wildfire management strategy. It also highlights the results of a survey of numerous stakeholders conducted on landscape fires in Ukraine. Based on the review of global and regional experiences, as well as existing fire risks in Ukraine, recommendations were developed for implementing an integrated landscape level national fire management approach.

Nonuse of Forest Residues is Impermissible Overlook for the Country with Limited Natural Resources

In human history forests always satisfied different needs of people like: food, energy, medicine plants, wood materials, fodder. From 20th century wood energy gradually was substituted by fossil fuel. But wood still remained irreplaceable resource for construction, furniture, paper industry. At the same time many new wood products have been developed from wood and agriculture residues, so called engineered wood, like: plywood, chipboards, fiberboards, MDF, etc. Bio-economy today uses biomass for manufacturing bio-based chemicals, plastics, pharmaceutical products as well as, residues for generating bio-energy. Nowadays, when the fossil fuel age declines due to its exhaustible character biomass regains a new importance. Biomass currently is the dominating renewable energy source for multiple use. Gradual substitution of fossil fuel by renewable energies instigates rapid growth of all renewable energy carriers like wind, solar, hydro, geo-thermal and bio-energy. It is the best strategy against climate change too.

Production of green bacterial cellulose nanofibers by utilizing renewable resources of algae in comparison with agricultural residue

Bacterial Cellulose (BC) was synthesized through utilizing algae as a sustainable and renewable carbon source in comparison with agriculture residues (i.e., Wheat Straws (WS)). BC was produced in separate hydrolysis and fermentation method (SHF) using Gluconacetobacter xylinum (G.xylinum). Results for the individual and total sugars were analyzed in comparison with corresponding results from WS hydrolysis. Results show that highest total sugars content was obtained with algae samples that were hydrolyzed using enzymes (Cellulase, β-glycosidase, and Xylanase) and produced 27.58 g/L. Similarly, WS hydrolysis under same conditions produced 52.12 g/L. The lowest total sugars production was obtained with algae sample that was hydrolyzed using 1% of acid at 121°C. Produced sugars were utilized in SHF to produce BC, with highest production of 4.86 g/L BC was achieved with algae sample that went through enzymatic hydrolysis. The equivalent production that was obtained from WS hydrolysis was 10.6 g/L Results obtained from individual sugars indicated that among all individual sugars glucose was maximum consumed i.e. 80-85%of glucose sugar was consumed where the lowest was arabinose which was only 50% consumed during fermentation. The lower production of BC using algae compared to WS (approximately half) as algae we used was unprocessed means it had oil content in it. About 30-60% of algae dry weight was utilized for production of oil and rest amount of feedstock was only used for hydrolysis and fermentation.

Production of green bacterial cellulose nanofibers by utilizing renewable resources of algae in comparison with agricultural residue

Bacterial Cellulose (BC) was synthesized through utilizing algae as a sustainable and renewable carbon source in comparison with agriculture residues (i.e., Wheat Straws (WS)). BC was produced in separate hydrolysis and fermentation method (SHF) using Gluconacetobacter xylinum (G.xylinum). Results for the individual and total sugars were analyzed in comparison with corresponding results from WS hydrolysis. Results show that highest total sugars content was obtained with algae samples that were hydrolyzed using enzymes (Cellulase, β-glycosidase, and Xylanase) and produced 27.58 g/L. Similarly, WS hydrolysis under same conditions produced 52.12 g/L. The lowest total sugars production was obtained with algae sample that was hydrolyzed using 1% of acid at 121°C. Produced sugars were utilized in SHF to produce BC, with highest production of 4.86 g/L BC was achieved with algae sample that went through enzymatic hydrolysis. The equivalent production that was obtained from WS hydrolysis was 10.6 g/L Results obtained from individual sugars indicated that among all individual sugars glucose was maximum consumed i.e. 80-85%of glucose sugar was consumed where the lowest was arabinose which was only 50% consumed during fermentation. The lower production of BC using algae compared to WS (approximately half) as algae we used was unprocessed means it had oil content in it. About 30-60% of algae dry weight was utilized for production of oil and rest amount of feedstock was only used for hydrolysis and fermentation.

Optimal Sugar Compostitions And Conditions For Enhanced Biobutanol Bioproduction From Agriculture Residues

Production of alternative non-fossil biofuels based on renewable resources has been the focus of research in the past few decades due to its environmental and economical advantages. The current study focuses on testing two Clostridia strains towards production of butanol. The work was performed in three parts: the first part includes introducing C acetobutylicum ATCC 4259 for butanol production and identifying the proper working conditions for this strain. The following part includes extending investigation of production to examine C. beijerinckiiBA101 and compare with results obtained from C. acetobutylicum. In the last part, an optimization study was conducted on a presently derived mathematical model in order to predict the best sugar composition in the feedstock for maximum production of butanol. Results showed that the agriculture residues are potential biomass resource for biofuel industry sin both Clostridia strains were successfully able to utilize all types of agricultural sugars including hexose and pentose. However, using C. beijerinkckii resulted in 53% higher butanol concentration than using introduced C. acetobutylicum. The yield was fairly comparable, while high acid accumulation found when using C. acetobutylicum made this strain inapplicable to anaerobic batch fermentation without effective system of pH control.

Optimal Sugar Compostitions And Conditions For Enhanced Biobutanol Bioproduction From Agriculture Residues

Production of alternative non-fossil biofuels based on renewable resources has been the focus of research in the past few decades due to its environmental and economical advantages. The current study focuses on testing two Clostridia strains towards production of butanol. The work was performed in three parts: the first part includes introducing C acetobutylicum ATCC 4259 for butanol production and identifying the proper working conditions for this strain. The following part includes extending investigation of production to examine C. beijerinckiiBA101 and compare with results obtained from C. acetobutylicum. In the last part, an optimization study was conducted on a presently derived mathematical model in order to predict the best sugar composition in the feedstock for maximum production of butanol. Results showed that the agriculture residues are potential biomass resource for biofuel industry sin both Clostridia strains were successfully able to utilize all types of agricultural sugars including hexose and pentose. However, using C. beijerinkckii resulted in 53% higher butanol concentration than using introduced C. acetobutylicum. The yield was fairly comparable, while high acid accumulation found when using C. acetobutylicum made this strain inapplicable to anaerobic batch fermentation without effective system of pH control.