scholarly journals An Overview of Recent Advancements in Microbial Polyhydroxyalkanoates (PHA) Production from Dark Fermentation Acidogenic Effluents: A Path to an Integrated Bio-Refinery

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4297
Author(s):  
Rijuta Ganesh Saratale ◽  
Si-Kyung Cho ◽  
Ganesh Dattatraya Saratale ◽  
Manu Kumar ◽  
Ram Naresh Bharagava ◽  
...  
Keyword(s):  
Volatile Fatty Acids ◽  
Renewable Energy Sources ◽  
Value Added ◽  
Cost Effective ◽  
Research Progress ◽  
Carbon Substrate ◽  
Operational Parameters ◽  
Biomass Resources ◽  
Fermentative Hydrogen ◽  
Hydrogen Synthesis

Global energy consumption has been increasing in tandem with economic growth motivating researchers to focus on renewable energy sources. Dark fermentative hydrogen synthesis utilizing various biomass resources is a promising, less costly, and less energy-intensive bioprocess relative to other biohydrogen production routes. The generated acidogenic dark fermentative effluent [e.g., volatile fatty acids (VFAs)] has potential as a reliable and sustainable carbon substrate for polyhydroxyalkanoate (PHA) synthesis. PHA, an important alternative to petrochemical based polymers has attracted interest recently, owing to its biodegradability and biocompatibility. This review illustrates methods for the conversion of acidogenic effluents (VFAs), such as acetate, butyrate, propionate, lactate, valerate, and mixtures of VFAs, into the value-added compound PHA. In addition, the review provides a comprehensive update on research progress of VFAs to PHA conversion and related enhancement techniques including optimization of operational parameters, fermentation strategies, and genetic engineering approaches. Finally, potential bottlenecks and future directions for the conversion of VFAs to PHA are outlined. This review offers insights to researchers on an integrated biorefinery route for sustainable and cost-effective bioplastics production.

scholarly journals Dual Role of Grass Clippings As Buffering Agent and Biomass During Anaerobic Co-digestion With Food Waste

2021 ◽  
Author(s):  
Debkumar Chakraborty ◽  
Sankar Ganesh Palani ◽  
Makarand M. Ghangrekar ◽  
Anand N ◽  
Pankaj Pathak
Keyword(s):  
Food Waste ◽  
Volatile Fatty Acids ◽  
Hydrogen Generation ◽  
Value Added ◽  
Cost Effective ◽  
Organic Load ◽  
Hydrogen Yield ◽  
Alcohol Production ◽  
Redox Environment ◽  
Buffering Agent

Abstract There is a dire need to replace the chemical buffers that regulate the redox environment in single-stage anaerobic digestion (AD) of food waste (FW). Hence, the applicability of grass clippings (GC) as an eco-friendly buffering agent and biomass during the anaerobic co-digestion of FW was explored. A focus was primarily given on the effects of GC on the redox environment and acidogenesis. Concomitantly the production of volatile fatty acids, hydrogen and methane in mesophilic conditions was monitored. Organic load and substrate to inoculum ratio were kept constant in all the experiments, and no chemical buffer was used. The results revealed that GC regulated the redox environment by inhibiting rapid pH drop in the digester with 10 % GC. The addition of 2, 4, and 6 % GC promoted acidogenesis with increased production of acetic and butyric acids; whereas, 8 and 10 % GC promoted solventogenesis with ethyl alcohol production. Hydrogen generation from the experiments with GC was in the range of 27-30 % of the total biogas, which was marginally higher than from the control (25 %). Methane concentration was negligible in the biogas generated from all experiments. The acidification rate, VFA production/consumption rate, specific hydrogen yield, hydrogen conversion efficiency, and volatile solid removal were maximum and minimum in the reactors with 6 and 10 % GC, respectively. From the above results, it can be concluded that the addition of GC to FW would regulate the sudden pH changes and enhance the production of value-added biochemicals, to make the process cost-effective.

Cost Effective Synthesis and Fabrication of Phase-Pure Kesterite Cu2-xZn1.3SnS4 P-type Absorber Layer Thin Films by Solvent Based Process Technique for Photovoltaic Solar Energy Applications

2018 ◽  
Vol 7 (4) ◽  
pp. 36
Author(s):  
B. Khadambari ◽  
S. S. Bhattacharya
Keyword(s):  
Solar Energy ◽  
Renewable Energy Sources ◽  
Cost Effective ◽  
Absorber Layer ◽  
Window Layer ◽  
Energy Applications ◽  
Process Technique ◽  
Absorber Material ◽  
Effective Synthesis ◽  
P Type

Solar has become one of the fastest growing renewable energy sources. With the push towards sustainability it is an excellent solution to resolve the issue of our diminishing finite resources. Alternative photovoltaic systems are of much importance to utilize solar energy efficiently. The Cu-chalcopyrite compounds CuInS2 and CuInSe2 and their alloys provide absorber material of high absorption coefficients of the order of 105 cm-1. Cu2ZnSnS4 (CZTS) is more promising material for photovoltaic applications as Zn and Sn are abundant materials of earth’s crust. Further, the preparation of CZTS-ink facilitates the production of flexible solar cells. The device can be designed with Al doped ZnO as the front contact, n-type window layer (e.g. intrinsic ZnO); an n-type thin film buffer layer (e.g. CdS) and a p-type CZTS absorber layer with Molybdenum (Mo) substrate as back contact. In this study, CZTS films were synthesized by a non-vaccum solvent based process technique from a molecular-ink using a non toxic eco-friendly solvent dimethyl sulfoxide (DMSO). The deposited CZTS films were optimized and characterized by XRD, UV-visible spectroscopy and SEM.

Monitoring effluent quality in hypertrophic wastewater reservoirs using remote sensing

1996 ◽  
Vol 33 (8) ◽  
pp. 23-29 ◽  
Author(s):  
I. Dor ◽  
N. Ben-Yosef
Keyword(s):  
Water Quality ◽  
Theoretical Model ◽  
Principal Component ◽  
Cost Effective ◽  
Operational Parameters ◽  
Effluent Quality ◽  
Optical Images ◽  
Routine Monitoring ◽  
Cost Effective Method ◽  
Wastewater Quality

About one hundred and fifty wastewater reservoirs store effluents for irrigation in Israel. Effluent qualities differ according to the inflowing wastewater quality, the degree of pretreatment and the operational parameters. Certain aspects of water quality like concentration of organic matter, suspended solids and chlorophyll are significantly correlated with the water column transparency and colour. Accordingly optical images of the reservoirs obtained from the SPOT satellite demonstrate pronounced differences correlated with the water quality. The analysis of satellite multispectral images is based on a theoretical model. The model calculates, using the radiation transfer equation, the volume reflectance of the water body. Satellite images of 99 reservoirs were analyzed in the chromacity space in order to classify them according to water quality. Principal Component Analysis backed by the theoretical model increases the method sensitivity. Further elaboration of this approach will lead to the establishment of a time and cost effective method for the routine monitoring of these hypertrophic wastewater reservoirs.

scholarly journals Multi-Country Scale Assessment of Available Energy Recovery Potential Using Micro-Hydropower in Drinking, Pressurised Irrigation and Wastewater Networks, Covering Part of the EU

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 899
Author(s):  
Djordje Mitrovic ◽  
Miguel Crespo Chacón ◽  
Aida Mérida García ◽  
Jorge García Morillo ◽  
Juan Antonio Rodríguez Diaz ◽  
...  
Keyword(s):  
Drinking Water ◽  
Northern Ireland ◽  
Energy Recovery ◽  
Large Scale ◽  
Significant Proportion ◽  
Value Added ◽  
Cost Effective ◽  
Net Energy ◽  
Water Networks ◽  
Scale Assessment

Studies have shown micro-hydropower (MHP) opportunities for energy recovery and CO2 reductions in the water sector. This paper conducts a large-scale assessment of this potential using a dataset amassed across six EU countries (Ireland, Northern Ireland, Scotland, Wales, Spain, and Portugal) for the drinking water, irrigation, and wastewater sectors. Extrapolating the collected data, the total annual MHP potential was estimated between 482.3 and 821.6 GWh, depending on the assumptions, divided among Ireland (15.5–32.2 GWh), Scotland (17.8–139.7 GWh), Northern Ireland (5.9–8.2 GWh), Wales (10.2–8.1 GWh), Spain (375.3–539.9 GWh), and Portugal (57.6–93.5 GWh) and distributed across the drinking water (43–67%), irrigation (51–30%), and wastewater (6–3%) sectors. The findings demonstrated reductions in energy consumption in water networks between 1.7 and 13.0%. Forty-five percent of the energy estimated from the analysed sites was associated with just 3% of their number, having a power output capacity >15 kW. This demonstrated that a significant proportion of energy could be exploited at a small number of sites, with a valuable contribution to net energy efficiency gains and CO2 emission reductions. This also demonstrates cost-effective, value-added, multi-country benefits to policy makers, establishing the case to incentivise MHP in water networks to help achieve the desired CO2 emissions reductions targets.

scholarly journals Solid Biomass Energy Potential as a Development Opportunity for Rural Communities

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3398
Author(s):  
Mariusz Jerzy Stolarski ◽  
Paweł Dudziec ◽  
Michał Krzyżaniak ◽  
Ewelina Olba-Zięty
Keyword(s):  
Rural Communities ◽  
Rural Areas ◽  
Renewable Energy Sources ◽  
Biomass Energy ◽  
Energy Sources ◽  
Energy Potential ◽  
Development Opportunity ◽  
Biomass Resources ◽  
Administrative Units ◽  
Solid Biomass

Conventional energy sources often do not fully satisfy the needs of a modern economy, especially given the climate changes associated with them. These issues should be addressed by diversification of energy generation, including the development of renewable energy sources (RES). Solid biomass will play a major part in the process in Poland. The function of rural areas, along with a well-developed agricultural and forest economy sector, will be a key aspect in this as these areas are suitable for solid biomass acquisition in various ways. This study aimed to determine the solid biomass energy potential in the commune of Goworowo to illustrate the potential in the smallest administrative units of Poland. This research determined the environmental and natural conditions in the commune, which helped to identify the crucial usable solid biomass resources. The total energy potential of solid biomass resources in the commune of Goworowo amounted to 97,672 GJ y−1. The highest potential was accumulated in straw surplus (37,288 GJ y−1) and the lowest was in wood from roadside maintenance (113 GJ y−1). This study showed that rural areas could soon play a significant role in obtaining solid biomass, and individual communes could become spaces for the diversification of energy feedstock.

scholarly journals Optimisation of microalgal cultivation via nutrient-enhanced strategies: the biorefinery paradigm

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Gonzalo M. Figueroa-Torres ◽  
Jon K. Pittman ◽  
Constantinos Theodoropoulos
Keyword(s):  
Kinetic Model ◽  
Growth Dynamics ◽  
Value Added ◽  
Cost Effective ◽  
Predictive Modelling ◽  
Nitrogen And Phosphorus ◽  
Predictive Capacity ◽  
Microalgal Biomass ◽  
Microalgal Cultivation ◽  
Lipid Formation

Abstract Background The production of microalgal biofuels, despite their sustainable and renowned potential, is not yet cost-effective compared to current conventional fuel technologies. However, the biorefinery concept increases the prospects of microalgal biomass as an economically viable feedstock suitable for the co-production of multiple biofuels along with value-added chemicals. To integrate biofuels production within the framework of a microalgae biorefinery, it is not only necessary to exploit multi-product platforms, but also to identify optimal microalgal cultivation strategies maximising the microalgal metabolites from which biofuels are obtained: starch and lipids. Whilst nutrient limitation is widely known for increasing starch and lipid formation, this cultivation strategy can greatly reduce microalgal growth. This work presents an optimisation framework combining predictive modelling and experimental methodologies to effectively simulate and predict microalgal growth dynamics and identify optimal cultivation strategies. Results Microalgal cultivation strategies for maximised starch and lipid formation were successfully established by developing a multi-parametric kinetic model suitable for the prediction of mixotrophic microalgal growth dynamics co-limited by nitrogen and phosphorus. The model’s high predictive capacity was experimentally validated against various datasets obtained from laboratory-scale cultures of Chlamydomonas reinhardtii CCAP 11/32C subject to different initial nutrient regimes. The identified model-based optimal cultivation strategies were further validated experimentally and yielded significant increases in starch (+ 270%) and lipid (+ 74%) production against a non-optimised strategy. Conclusions The optimised microalgal cultivation scenarios for maximised starch and lipids, as identified by the kinetic model presented here, highlight the benefits of exploiting modelling frameworks as optimisation tools that facilitate the development and commercialisation of microalgae-to-fuel technologies.

scholarly journals Comparison between Concentrated Solar Power and Gas-Based Generation in Terms of Economic and Flexibility-Related Aspects in Chile

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1063
Author(s):  
Catalina Hernández Moris ◽  
Maria Teresa Cerda Guevara ◽  
Alois Salmon ◽  
Alvaro Lorca
Keyword(s):  
Natural Gas ◽  
Solar Power ◽  
Renewable Energy Sources ◽  
Cost Effective ◽  
Hybrid Plant ◽  
Point Of View ◽  
Concentrated Solar Power ◽  
Economic Point ◽  
Hybrid Plants ◽  
Cost Of Energy

The energy sector in Chile demands a significant increase in renewable energy sources in the near future, and concentrated solar power (CSP) technologies are becoming increasingly competitive as compared to natural gas plants. Motivated by this, this paper presents a comparison between solar technologies such as hybrid plants and natural gas-based thermal technologies, as both technologies share several characteristics that are comparable and beneficial for the power grid. This comparison is made from an economic point of view using the Levelized Cost of Energy (LCOE) metric and in terms of the systemic benefits related to flexibility, which is very much required due to the current decarbonization scenario of Chile’s energy matrix. The results show that the LCOE of the four hybrid plant models studied is lower than the LCOE of the gas plant. A solar hybrid plant configuration composed of a photovoltaic and solar tower plant (STP) with 13 h of storage and without generation restrictions has an LCOE 53 USD/MWh, while the natural gas technology evaluated with an 85% plant factor and a variable fuel cost of 2.0 USD/MMBtu has an LCOE of 86 USD/MWh. Thus, solar hybrid plants under a particular set of conditions are shown to be more cost-effective than their closest competitor for the Chilean grid while still providing significant dispatchability and flexibility.

Aligning the flow cytometric evaluation with the diagnostic need: an evidence-based approach

2017 ◽  
Vol 70 (9) ◽  
pp. 740-744 ◽  
Author(s):  
Dawn Williams-Voorbeijtel ◽  
Francisco Sanchez ◽  
Christine G Roth
Keyword(s):  
Clinical Care ◽  
Cost Savings ◽  
Value Added ◽  
Cost Effective ◽  
Just In Time ◽  
Evidence Based ◽  
Flow Cytometric ◽  
A Value ◽  
Screening Approach ◽  
Minimum Requirements

AimsElimination of non-value added testing without compromising high-quality clinical care is an important mandate for laboratories in a value-based reimbursement system. The goal of this study was to determine the optimal combination of flow cytometric markers for a screening approach that balances efficiency and accuracy.MethodsAn audit over 9 months of flow cytometric testing was performed, including rereview of all dot plots from positive cases.ResultsOf the 807 cases in which leukaemia/lymphoma testing was performed, 23 were non-diagnostic and 189 represented bronchoalveolar lavage specimens. Of the remaining 595 cases, 137 (23%) were positive for an abnormal haematolymphoid population. Review of the positive cases identified minimum requirements for a screening tube as well as analysis strategies to overcome the diagnostic pitfalls noted. It is estimated that 38% fewer antibodies would be used in a screening approach, representing an opportunity for significant cost savings.ConclusionsWe provide a framework for developing an evidence-based screening combination for cost-effective characterisation of haematolymphoid malignancies, promoting adoption of ‘just-in-time’ testing systems that tailor the evaluation to the diagnostic need.

Processing and Value Addition of Bamboo Shoots for Utilization as Food Products

2020 ◽  
Vol 27 (1) ◽  
pp. 27-32
Author(s):  
Ashok Kumar Pandey ◽  
Keyword(s):  
Shelf Life ◽  
Value Added ◽  
Cost Effective ◽  
Nutrient Content ◽  
Food Products ◽  
Value Addition ◽  
Mineral Contents ◽  
Bamboo Shoots ◽  
Processed Products ◽  
Edible Products

Bamboo shoots being low in fat, high in dietary fiber and rich in mineral contents have been consumed traditionally by the people world over. Besides nutrients it also contains some anti-nutrients e.g. cyanogens. Due to seasonal availability of bamboo shoots, processing for reducing anti-nutrients in raw shoots while keeping nutrients intact and enhancement of shelf life of the value added products assume great significance for its utilization. This paper focuses on post harvest processing and value addition of bamboo shoots for its utilization as food products. Juvenile bamboo shoots of Bambusa bambos, B. tulda, Dendrocalamus asper and D. strictus were collected and processed, by boiling in brine solution, to remove the anti-nutrients (cyanogen). A simple, efficient and cost effective processing method for bamboo shoots was developed. This method significantly reduces the amount of cyanogens and retains considerable amount of nutrients and thus may be utilized for processing of bamboo shoots. Different value added edible products viz. chunks or bari (by adding pulses), pickle, sauce and papad (by adding potato) were prepared. All products were good in taste and texture. Nutritional analysis was done to determine the shelf life of the products. The nutrient content of processed products (chunks, sauce, pickle and papad) showed a gradual decrease and need to be consumed within 6 months from the date of making. However, in case of papad the carbohydrate content did not decrease much but the taste was not acceptable after 8 months. Whereas, in case of pickles, even nutrient content decreased but the product was acceptable even after two years after preparation as it was good in taste and texture. Thus, processing and value addition practices can be considered as key to the future of sustainable management of bamboo resources because they not only provide quality edible products but also enable harvesters/collectors to get better income opportunities.

Insights on the Advancements of In Silico Metabolic Studies of Succinic Acid Producing Microorganisms: A Review with Emphasis on Actinobacillus succinogenes

Fermentation ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 220
Author(s):  
Wubliker Dessie ◽  
Zongcheng Wang ◽  
Xiaofang Luo ◽  
Meifeng Wang ◽  
Zuodong Qin
Keyword(s):  
Succinic Acid ◽  
In Silico ◽  
Value Added ◽  
Research Progress ◽  
Efficient Production ◽  
Actinobacillus Succinogenes ◽  
Cell Factories ◽  
In Silico Studies ◽  
Current Scenario ◽  
Critical Problems

Succinic acid (SA) is one of the top candidate value-added chemicals that can be produced from biomass via microbial fermentation. A considerable number of cell factories have been proposed in the past two decades as native as well as non-native SA producers. Actinobacillus succinogenes is among the best and earliest known natural SA producers. However, its industrial application has not yet been realized due to various underlying challenges. Previous studies revealed that the optimization of environmental conditions alone could not entirely resolve these critical problems. On the other hand, microbial in silico metabolic modeling approaches have lately been the center of attention and have been applied for the efficient production of valuable commodities including SA. Then again, literature survey results indicated the absence of up-to-date reviews assessing this issue, specifically concerning SA production. Hence, this review was designed to discuss accomplishments and future perspectives of in silico studies on the metabolic capabilities of SA producers. Herein, research progress on SA and A. succinogenes, pathways involved in SA production, metabolic models of SA-producing microorganisms, and status, limitations and prospects on in silico studies of A. succinogenes were elaborated. All in all, this review is believed to provide insights to understand the current scenario and to develop efficient mathematical models for designing robust SA-producing microbial strains.

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