Vertical-algal-biofilm enhanced raceway pond for cost-effective wastewater treatment and value-added products production

2018 ◽  
Vol 139 ◽  
pp. 144-157 ◽  
Author(s):  
Qi Zhang ◽  
Zhigang Yu ◽  
Liandong Zhu ◽  
Ting Ye ◽  
Jiaolan Zuo ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Value Added ◽  
Cost Effective ◽  
Raceway Pond ◽  
Algal Biofilm ◽  
Value Added Products

scholarly journals Exploiting xylan as sugar donor for the synthesis of an antiproliferative xyloside using an enzyme cascade

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Manuel Nieto-Domínguez ◽  
José Alberto Martínez-Fernández ◽  
Beatriz Fernández de Toro ◽  
Juan A. Méndez-Líter ◽  
Francisco Javier Cañada ◽  
...  
Keyword(s):  
Chemical Synthesis ◽  
Biomass Conversion ◽  
Value Added ◽  
Cost Effective ◽  
Raw Material ◽  
Birchwood Xylan ◽  
Enzyme Cascade ◽  
Antiproliferative Agent ◽  
Xylanolytic Enzymes ◽  
Value Added Products

Abstract Background Currently, industrial societies are seeking for green alternatives to conventional chemical synthesis. This demand has merged with the efforts to convert lignocellulosic biomass into value-added products. In this context, xylan, as one of main components of lignocellulose, has emerged as a raw material with high potential for advancing towards a sustainable economy. Results In this study, the recombinant endoxylanase rXynM from the ascomycete Talaromyces amestolkiae has been heterologously expressed in Pichia pastoris and used as one of the catalysts of an enzyme cascade developed to synthesize the antiproliferative 2-(6-hydroxynaphthyl) β-d-xylopyranoside, by transglycosylation of 2,6-dihydroxynaphthalene. The approach combines the use of two fungal xylanolytic enzymes, rXynM and the β-xylosidase rBxTW1 from the same fungus, with the cost-effective substrate xylan. The reaction conditions for the cascade were optimized by a Central Composite Design. Maximal productions of 0.59 and 0.38 g/L were reached using beechwood xylan and birchwood xylan, respectively. For comparison, xylans from other sources were tested in the same reaction, suggesting that a specific optimization is required for each xylan variety. The results obtained using this enzyme cascade and xylan were similar or better to those previously reported for a single catalyst and xylobiose, an expensive sugar donor. Conclusions Beechwood and birchwood xylan, two polysaccharides easily available from biomass, were used in a novel enzyme cascade to synthetize an antiproliferative agent. The approach represents a green alternative to the conventional chemical synthesis of 2-(6-hydroxynaphthyl) β-d-xylopyranoside using a cost-effective substrate. The work highlights the role of xylan as a raw material for producing value-added products and the potential of fungal xylanolytic enzymes in the biomass conversion.

scholarly journals Integrated Biotechnology Management of Biosolids: Sustainable Ways to Produce Value—Added Products

2021 ◽  
Vol 3 ◽  
Author(s):  
Vasanth Kumar Vaithyanathan ◽  
Hubert Cabana
Keyword(s):  
Wastewater Treatment ◽  
Solid Waste ◽  
Dry Matter ◽  
Municipal Wastewater ◽  
Value Added ◽  
Resource Recovery ◽  
Wastewater Sludge ◽  
Waste Biomass ◽  
Worldwide Production ◽  
Value Added Products

Biosolids (BS) are organic dry matter produced from wastewater treatment plants (WWTPs). The current yearly worldwide production of BS is estimated to be around 100–125 million tons and is expected to continuously increase to around 150–200 million tons by 2025. Wastewater treatment industries across the globe strive to achieve a green and sustainable manufacturing base for the management of enormous amounts of municipal BS, which are rich in nutrients and organic dry matter along with contaminants. The management of these organic-rich wastes through environmentally friendly recovery technologies is a major challenge. The need to improve waste biomass disposal by biological development and develop more economically viable processes has led to a focus on the transformation of waste resources into value-added products (VAP). This paper assesses the leading disposal methods (based on volume and contaminant reduction) and reviews the state of biotechnological processes for VAP recovery from municipal wastewater sludge (untreated solid waste residual) and BS (stabilized solid waste which meets criteria for its use in land). A review of the anaerobic and aerobic digestion processes is presented to provide a holistic overview of this growing research field. Furthermore, the paper also sheds light on the pollutant reduction and resource recovery approaches for enzymes, bioflocculants, bioplastics, biopesticides, and biogas as a mean to represent BS as a potential opportunity for WWTPs. However, only a few technologies have been implemented for VAP resource recovery and a shift from WWTPs to waste resource recovery facilities is still far from being achieved.

scholarly journals Valorization of Wastewater Resources Into Biofuel and Value-Added Products Using Microalgal System

2021 ◽  
Vol 9 ◽  
Author(s):  
Kanika Arora ◽  
Parneet Kaur ◽  
Pradeep Kumar ◽  
Archana Singh ◽  
Sanjay Kumar Singh Patel ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Industrial Wastewater ◽  
Microbial Growth ◽  
Oxygen Demand ◽  
Value Added ◽  
Aquatic Organisms ◽  
Pilot Scale ◽  
Microalgal Biomass ◽  
Microalgal Cultivation ◽  
Value Added Products

Wastewater is not a liability, instead considered as a resource for microbial fermentation and value-added products. Most of the wastewater contains various nutrients like nitrates and phosphates apart from the organic constituents that favor microbial growth. Microalgae are unicellular aquatic organisms and are widely used for wastewater treatment. Various cultivation methods such as open, closed, and integrated have been reported for microalgal cultivation to treat wastewater and resource recovery simultaneously. Microalgal growth is affected by various factors such as sunlight, temperature, pH, and nutrients that affect the growth rate of microalgae. Microalgae can consume urea, phosphates, and metals such as magnesium, zinc, lead, cadmium, arsenic, etc. for their growth and reduces the biochemical oxygen demand (BOD). The microalgal biomass produced during the wastewater treatment can be further used to produce carbon-neutral products such as biofuel, feed, bio-fertilizer, bioplastic, and exopolysaccharides. Integration of wastewater treatment with microalgal bio-refinery not only solves the wastewater treatment problem but also generates revenue and supports a sustainable and circular bio-economy. The present review will highlight the current and advanced methods used to integrate microalgae for the complete reclamation of nutrients from industrial wastewater sources and their utilization for value-added compound production. Furthermore, pertaining challenges are briefly discussed along with the techno-economic analysis of current pilot-scale projects worldwide.

scholarly journals Sustainable Cost-Effective Microalgae Harvesting Strategies for the Production of Biofuel and Oleochemicals

2020 ◽  
Author(s):  
Suchitra Rakesh ◽  
Jayakumar TharunKumar ◽  
Bhavya Sri ◽  
Karuppaiyan Jothibasu ◽  
Subburamu Karthikeyan
Keyword(s):  
Low Cost ◽  
Biomass Concentration ◽  
Value Added ◽  
Cost Effective ◽  
Future Perspective ◽  
Dissolved Air Flotation ◽  
Capital Costs ◽  
Microalgae Harvesting ◽  
Problematic Area ◽  
Value Added Products

Microalgae have been explored for sustainable production of biofuel and chemicals. Microalgae is promising feed stock for the production of several oleochemicals. It has the ability to utilize a variety of low cost feed stocks, accumulated large quantities of lipids and variety of value added products in their biomass. One of the major obstacles associated with the conversion of algae into value-added products is harvesting. The harvesting of algae is the most problematic area due to its low sedimentation rate, low biomass concentration, and high capital costs. Harvesting of algae is carried out by different physical, chemical, mechanical, biological, and electrolytic methods such as sedimentation, centrifugation, microstraining, dissolved air flotation, electrolytic flotation, chemical flocculation, bioflocculation, autoflocculation, Filtration. This review highlights the various methods of microalgae harvesting with advantages and future perspective of sustainable and cost-effective harvesting of microalgae.

scholarly journals Potential Use of Microbial Enzymes for the Conversion of Plastic Waste Into Value-Added Products: A Viable Solution

2021 ◽  
Vol 12 ◽  
Author(s):  
Muhammad Tamoor ◽  
Nadia A. Samak ◽  
Yunpu Jia ◽  
Muhammad Umar Mushtaq ◽  
Hassan Sher ◽  
...  
Keyword(s):  
Value Added ◽  
Cost Effective ◽  
Building Blocks ◽  
Waste Recycling ◽  
Plastic Waste ◽  
Fuel Oil ◽  
Environmental Crisis ◽  
Thermomyces Lanuginosus ◽  
Microbial Enzymes ◽  
Value Added Products

The widespread use of commercial polymers composed of a mixture of polylactic acid and polyethene terephthalate (PLA-PET) in bottles and other packaging materials has caused a massive environmental crisis. The valorization of these contaminants via cost-effective technologies is urgently needed to achieve a circular economy. The enzymatic hydrolysis of PLA-PET contaminants plays a vital role in environmentally friendly strategies for plastic waste recycling and degradation. In this review, the potential roles of microbial enzymes for solving this critical problem are highlighted. Various enzymes involved in PLA-PET recycling and bioconversion, such as PETase and MHETase produced by Ideonella sakaiensis; esterases produced by Bacillus and Nocardia; lipases produced by Thermomyces lanuginosus, Candida antarctica, Triticum aestivum, and Burkholderia spp.; and leaf-branch compost cutinases are critically discussed. Strategies for the utilization of PLA-PET’s carbon content as C1 building blocks were investigated for the production of new plastic monomers and different value-added products, such as cyclic acetals, 1,3-propanediol, and vanillin. The bioconversion of PET-PLA degradation monomers to polyhydroxyalkanoate biopolymers by Pseudomonas and Halomonas strains was addressed in detail. Different solutions to the production of biodegradable plastics from food waste, agricultural residues, and polyhydroxybutyrate (PHB)-accumulating bacteria were discussed. Fuel oil production via PLA-PET thermal pyrolysis and possible hybrid integration techniques for the incorporation of thermostable plastic degradation enzymes for the conversion into fuel oil is explained in detail.

scholarly journals Advances in Valorization of Lignocellulosic Biomass towards Energy Generation

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 309
Author(s):  
Ikram ul Haq ◽  
Kinza Qaisar ◽  
Ali Nawaz ◽  
Fatima Akram ◽  
Hamid Mukhtar ◽  
...  
Keyword(s):  
Lignocellulosic Biomass ◽  
Sustainable Energy ◽  
Value Added ◽  
Cost Effective ◽  
Energy Output ◽  
Sustainable Energy Systems ◽  
Pros And Cons ◽  
Fuel Source ◽  
Value Added Products

The booming demand for energy across the world, especially for petroleum-based fuels, has led to the search for a long-term solution as a perfect source of sustainable energy. Lignocellulosic biomass resolves this obstacle as it is a readily available, inexpensive, and renewable fuel source that fulfills the criteria of sustainability. Valorization of lignocellulosic biomass and its components into value-added products maximizes the energy output and promotes the approach of lignocellulosic biorefinery. However, disruption of the recalcitrant structure of lignocellulosic biomass (LCB) via pretreatment technologies is costly and power-/heat-consuming. Therefore, devising an effective pretreatment method is a challenge. Likewise, the thermochemical and biological lignocellulosic conversion poses problems of efficiency, operational costs, and energy consumption. The advent of integrated technologies would probably resolve this problem. However, it is yet to be explored how to make it applicable at a commercial scale. This article will concisely review basic concepts of lignocellulosic composition and the routes opted by them to produce bioenergy. Moreover, it will also discuss the pros and cons of the pretreatment and conversion methods of lignocellulosic biomass. This critical analysis will bring to light the solutions for efficient and cost-effective conversion of lignocellulosic biomass that would pave the way for the development of sustainable energy systems.

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