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Laccase production by Pleurotus ostreatus using cassava waste and its application in remediation of phenolic and polycyclic aromatic hydrocarbon-contaminated lignocellulosic biorefinery wastewater
2022
Kumar, Vaidyanathan Vinoth | Venkataraman, Swethaa | Kumar, P Senthil | George, Jenet | Rajendran, Devi Sri | Shaji, Anna | Lawrence, Nicole | Saikia, Kongkona | Rathankumar, Abiram Karanam
The treatment of contaminants from lignocellulosic biorefinery effluent has recently been identified as a unique challenge. This study focuses on removing phenolic contaminants and polycyclic aromatic hydrocarbons (PAHs) from lignocellulosic biorefinery wastewater (BRW) applying a laccase-assisted approach. Cassava waste was used as a substrate to produce the maximum yield of laccase enzyme (3.9 U/g) from Pleurotus ostreatus. Among the different inducers supplemented, CuSO₄ (0.5 mM) showed an eight-fold increase in enzyme production (30.8 U/g) after 240 h of incubation. The catalytic efficiency of laccase was observed as 128.7 ± 8.47 S⁻¹mM⁻¹ for syringaldazine oxidation at optimum pH 4.0 and 40 °C. Laccase activity was completely inhibited by lead (II) ion, mercury (II) ion, sodium dodecyl sulphate, sodium azide and 1,4 dithiothretiol and induced significantly by manganese (II) ion and rhamnolipid. After treating BRW with laccase, the concentrations of PAHs and phenolic contaminants of 1144 μg/L and 46160 μg/L were reduced to 96 μg/L and 16100 μg/L, respectively. The ability of laccase to effectively degrade PAHs in the presence of different phenolic compounds implies that phenolic contaminants may play a role in PAHs degradation. After 240 h, organic contaminants were removed from BRW in the following order: phenol >2,4-dinitrophenol > 2-methyl-4,6-dinitrophenol > 2,3,4,6-tetrachlorophenol > acenaphthene > fluorine > phenanthrene > fluoranthene > pyrene > anthracene > chrysene > naphthalene > benzo(a)anthracene > benzo(a)pyrene > benzo(b)fluoranthene > pentachlorophenol > indeno(1,2,3-cd)pyrene > benzo(j) fluoranthene > benzo[k]fluoranthène. The multiple contaminant remediation from the BRW by enzymatic method, clearly suggests that the laccase can be used as a bioremediation tool for the treatment of wastewater from various industries.
Show more [+] Less [-]Dietary diversity, environment and health-related factors of under-five children: evidence from cassava commercialization households in rural South-West Nigeria
2022
Otekunrin, Olutosin Ademola | Otekunrin, Oluwaseun Aramide | Ayinde, Idris Akanbi | Sanusi, Rahman Akintayo | Onabanjo, Oluseye Olusegun | Ariyo, Oluwaseun
Diverse and quality diets are crucial to sustainable growth and development of under-five children, especially those of rural farming households. This study investigated the dietary diversity, environment, and health-related factors of young children. The study employed the use of cross-sectional survey data from 140 under-five children of cassava farming households in Ogun and Oyo states, South-West Nigeria. The study estimated factors influencing dietary diversity of under-five children and assessed children dietary diversity, and the availability of some environment and health-related factors of the farming households. The findings indicated that 98.7% and 97.5% of children consumed grains, with roots and tubers while 36.7% and 36.3% consumed legumes in Ogun and Oyo states respectively. The results also found that 48.6% of children sampled met the minimum cut-off point of 4 food groups with dietary diversity mean score of 3.28. The logit regression analysis indicated that child’s age, mothers’ age, distance to farm, and food expenditure were among the significant determinants of children dietary diversity. Therefore, this study seeks the collaborative efforts of stakeholders in providing nutrition-sensitive intervention programs for household members, especially mothers and young children in order to promote consumption of diversified diets and enhance healthy living of rural farming households.
Show more [+] Less [-]Occurrence of BTEX from petroleum hydrocarbons in surface water, sediment, and biota from Ubeji Creek of Delta State, Nigeria
2021
Asejeje, Gbolahan Iyiola | Ipeaiyeda, Ayodele Rotimi | Onianwa, Percy Chuks
Petroleum exploration and production activities pose great threat worldwide in the marine environment with numerous occurrences of spills every year. Ubeji Creek in Nigeria suffers environmental pollution attributable to petroleum exploration. The hydrocarbons in petroleum encompass a large number of toxicants such as BTEX, which are frequently discharged into water bodies during spillage. In terms of scope, this study assessed for the first time BTEX levels in surface water, sediment, and biota of the Ubeji Creek. Environmental samples were collected at designated sampling locations along the Ubeji Creek quarterly for 2 years. Water quality was determined in situ, while BTEX levels in water, sediment, and biota were assessed in the laboratory using GC-FID. The physico-chemical characteristics of water were within the acceptable WHO limits with the exception of DO of 3.01 ± 0.25 mg/L. Organic pollution load could have contributed to the depression of DO level below the limit. BTEX of 5.57 ± 0.62 mg/kg in sediment samples was higher than the level in control sample. The BTEX levels in fish, shrimps, pawpaw fruit, pineapple tissue, bitter leaf, and cassava were 0.37 ± 0.05, 0.39 ± 0.01, 0.56 ± 0.02, 1.35 ± 0.04, 0.46 ± 0.06, and 0.22 ± 0.01 mg/kg, respectively. Accumulation of BTEX in this biota can affect their nutritive quality and consequently pose threat to humans who daily consume them.
Show more [+] Less [-]Cyanogenic Residues: Environmental Impacts, Complexation with Humic Substances, and Possible Application as Biofertilizer
2014
Souza, Shenia O. | Oliveira, Luciana C. | Cavagis, Alexandre D. M. | Botero, Wander G.
The disposal of cyanogenic residues from the processing of cassava, during the flour production in certain regions of the Brazilian northeastern, has been a cause of concern in recent years, since this practice may lead to environmental imbalances. The results obtained in this work show a possible impact caused by the release of this kind of waste into water bodies, as well as its potential use as biofertilizer, mainly due to its high nutrient content. Humic substances (HS) from water and soil showed high interaction with cyanide ions (CN⁻), being the main responsible for the bioavailability of these ions into the environment. Furthermore, studies in microcosms propose viable and low-cost alternatives to decrease the levels of CN⁻ions in the liquid waste (called “manipueira”), as well as its potential use as biofertilizer.
Show more [+] Less [-]Energy crop as an environmentally sustainable reclamation option for post-mining sites: a life cycle assessment of cassava planting in Vietnam
2022
Tran, Ha P. | Luong, Anh D. | Van, Anh D. | Nguyen, Tuyet T. A.
Using post-mining areas for planting energy crops has emerged as a promising and sustainable reclamation solution due to its potential contributions to environmental protection, land restoration, and especially energy security. However, to ensure the sustainability of this reclamation solution, its environmental performance needs to be thoroughly assessed case by case. Located in Ha Thuong Commune, Dai Tu District, Thai Nguyen Province in northern Vietnam, Nui Phao is the world’s largest tungsten mine. To restore post-mining sites at Nui Phao, cassava planting for ethanol production was one of the proposed measures. To support the decision-making, this study employs life cycle assessment to thoroughly evaluate the environmental performance and potential environmental benefits/costs of cassava-based reclamation system in terms of resource consumption and green house gas (GHG) emission. The results show that cassava-based reclamation might bring significant environmental benefits in terms of fossil fuel saving and GHGs reduction (i.e., reduce 50% fossil fuel consumption and 36% GHGs emission); however, it does not bring any benefit in terms of water and land resource consumption. Moreover, the results define cassava cultivation as the “hot spot” of the system, where innovations to enhance the yield and reduce water and fertilizer consumption are required to improve the environmental performance of the cassava-based reclamation system.
Show more [+] Less [-]Investigating food insecurity, health and environment-related factors, and agricultural commercialization in Southwestern Nigeria: evidence from smallholder farming households
2022
Otekunrin, Olutosin Ademola
Hunger and food insecurity remained some of the serious challenges facing our world in present time with great concerns from Sub-Saharan Africa especially countries like Nigeria. This study investigates food insecurity (FI), health and environment-related factors, and agricultural commercialization among smallholder farm households. This study was conducted in Southwestern Nigeria utilizing cross-sectional survey data from 352 farm households and employed multi-stage sampling procedure. The household FI levels was determined using food insecurity access scale (HFIAS), crop commercialization index (CCI) was used to compute each household’s CCI (four levels), while ordered logit model was used to analyse factors influencing FI. Health and environment-related factors’ access were assessed across each FI category. The results indicated that about 13% of cassava farm households are non-participant in the marketing of their produce. The findings revealed that less than 20%, 30%. and 40% of households in all four FI categories had access to piped water, improved toilet facilities, and electricity respectively. The ordered logit regression analysis indicated that age, gender, education level, farm experience, nonfarm income, and ownership of motorcycle significantly influencing FI in the study areas. Therefore, this study stressed the implementation of policy actions capable of promoting rural infrastructure development that will lead to increased agricultural production, marketing, and improved quality of life of rural dwellers.
Show more [+] Less [-]Removal of High Levels of Cyanide and COD from Cassava Industrial Wastewater by a Fixed-Film Sequencing Batch Reactor
2020
Potivichayanon, Siraporn | Toensakes, Rattana | Supromin, Nootjalee | Seaung, Ketkanok
The fixed-film sequencing batch reactor, or F-SBR, was developed to treat high organic compound levels and toxic cyanide concentrations in cassava wastewater. The performance of the F-SBR was compared with that of a conventional sequencing batch reactor, or SBR, that was operated with organic compound contents of 16,266.67–26,666 mg COD/L and 132.92–252.66 mg CN⁻/L. The cyanide and chemical oxygen demand removal efficiencies of the conventional SBR system were 42.61% and 36.83%, respectively, while those of the F-SBR were 77.95% and 74.43%, respectively; the cyanide removal efficiency reached 95.45% when the hydraulic retention time was increased to 5 days, and the F-SBR was very effective for the complete removal of cyanide when the hydraulic retention time was increased to 10 days. This effectiveness was similar to the effectiveness of chemical oxygen demand removal, which reached 40–78% efficiency with the F-SBR system. These results showed that the immobilization of cyanide-degrading bacteria such as Agrobacterium tumefaciens SUTS 1 and Pseudomonas monteilii SUTS 2 carried out with a polypropylene ring in a fixed-film aerobic system enhanced the performance of the reactor and can be successfully applied for cyanide and chemical oxygen demand removal from industrial wastewater with high cyanide and chemical oxygen demand concentrations. This study may provide a promising alternative technique that reduces economic operation costs in solving wastewater contamination problems.
Show more [+] Less [-]Microalgae cultivation in wastewater from agricultural industries to benefit next generation of bioremediation: a bibliometric analysis
2022
Melo, Jessica Muniz | Ribeiro, Marina Ronchesel | Telles, Tiago Santos | Amaral, Higo Forlan | Andrade, Diva Souza
The aim of this study was to provide a bibliometric analysis and mapping of existing scientific papers, focusing on microalgae cultivation coupled with biomass production and bioremediation of wastewater from agricultural industries, including cassava, dairy, and coffee. Using the Web of Science (WoS) database for the period 1996–2021, a search was performed using a keyword strategy, aiming at segregating the papers in groups. For the first search step, the keywords “wastewater treatment”, AND “microalgae”, AND “cassava” OR “dairy” OR “coffee” were used, resulting in 59 papers. For the second step, the keywords “wastewater treatment” AND “biomass productivity” AND “microalgae” AND “economic viability” OR “environmental impacts” were used, which resulted in 34 articles. In these papers, keywords such as “carbon dioxide biofixation” and “removal of nutrients by the production of biomass by microalgae” followed by “environmental and economic impacts” were highlighted. Some of these papers presented an analysis of the economic feasibility of the process, which reveal the state-of-the-art setup required to make the cultivation of microalgae economically viable. Researches focusing on the efficiency of microalgae biomass harvesting are needed to improve the integration of microalgae production in industrial eco-parks using wastewater to achieve the global goal of bioremediation and clean alternatives for renewable energy generation.
Show more [+] Less [-]Microalgae Technique for Bioremediation Treatment of Cassava Wastewater
2021
de Faria Ferreira Carraro, Cintia | Loures, Carla Cristina Almeida | de Castro, Jose Adilson
The present work aims to evaluate the potential for bioremediation and CO₂ fixation by cultivating the microalgae of the genus Chlorella minutissima in cassava wastewater. Experimental work investigated the growth of microalgae in the effluent and determined its growth rate based on different dilutions. Four culture media scenarios were created. The values measured in the laboratory were compared with a mathematical model adjusted based on the kinetic growth. The efficiency of the process was evaluated in terms of the reduction of the organic load, nutrient consumption, and cell count in the initial state (time 0) and complete growth (after the seventh day) using microscopy analysis. After biological treatment, a percentage of reduction of COD (chemical oxygen demand) of around 30%, TS (total solids) 75%, nutrient removal 92%, cyanide near 99%, and average CO₂ biofixation 0.19 g L⁻¹ d⁻¹ were observed. The reduction percentages are close to those found in the literature for other cultivation media. It was observed in this study that the biomass productivity and CO₂ fixation agree with those obtained in other studies and confirm the efficiency of the very tiny Chlorella microalgae with high photosynthetic capacity.
Show more [+] Less [-]Application of Biochar for Enhancing Cadmium and Zinc Phytostabilization in Vigna radiata L. Cultivation
2014
Prapagdee, Songkrit | Piyatiratitivorakul, Somkiat | Petsom, Amorn | Tawinteung, Nukoon
Cadmium (Cd) is a toxic and nonessential element. Because of its toxicity, Cd soil contamination is a major environmental risk to living organisms. Several studies have reported on the successful use of biochar to immobilize Cd in soil as it reduces Cd accumulation in plant parts. This research reports on the contrasting effect of biochar on enhancing Cd uptake by plants. A cassava stem biochar produced through low-temperature pyrolysis was applied to natural Cd-contaminated soil that also had a high zinc (Zn) concentration. Vigna radiata L. (a green bean) was grown in treatments receiving three biochar rates, i.e., 5, 10, and 15 %, respectively. The results showed that the 10 % biochar-amended soil had a positive effect on promoting plant growth and seed yield. Unfortunately, 15 % biochar-amended soil caused an adverse effect to plant growth. Cadmium uptake by plants increased with increasing biochar application rate. Zinc uptake by plants tended to decrease with biochar application. Cadmium and Zn bioavailability in soil was significantly reduced with an increasing biochar application rate. The results also showed that the biochar-amended soil could be an alternative and cost-effective method to promote plant growth and decrease Cd mobility in soil. The ratio of Cd concentration in plant root to soil was higher than 1, while the translocation factor from root to shoot was less than 1. These results indicate that the cultivation of V. radiata L. coupled with biochar application is an appropriate method to enhance Cd phytostabilization efficiency of V. radiata L. in Cd-polluted sites.
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