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The potential of organic wastes in eliminating old-aged petroleum pollution in saline soils: A case study in Khuzestan province
2023
Jafari Vafa, Hanye | Pourbabaee, Ahmad Ali | Alikhani, Hossein Ali | Yazdanfar, Najmeh | Khanali, Majid
Petroleum contains carcinogens and toxic substances that can have an unfavorable impact on environmental quality and human health when the soil becomes contaminated with crude oil. BBiostimulation and bioaugmentation are the main strategies in the bioremediation of oil-contaminated soils. To decompose old-aged petroleum pollution in saline soil, a full factorial experiment was utilized. The experiment was designed using a completely randomized design with four factors: bacterial inoculum, sugarcane bagasse, chemical fertilizer, and molasses. The application of these factors was conducted in four separate experiments: pretreatment of agricultural soil and spent mushroom compost, pretreatment of spent mushroom compost, pretreatment of agricultural soil, and no pretreatment. After a 60-day incubation period at 28 ˚C, the results showed that the organic wastes of molasses and spent mushroom compost in combination with bacterial inoculum reduced total petroleum hydrocarbons 38 and 33.3%, respectively. Molasses had a considerable impact on increasing the efficiency of bacterial inoculum 1 and bacterial inoculum 3. Similarly, spent mushroom compost was found to significantly affect bacterial inoculum 1. In addition, bagasse was observed to accelerate the bioremediation process by improving the physical conditions of the soil. In the pretreatment of agricultural soil, bagasse in combination with bacterial inoculum 1 and chemical fertilizer reduced the total petroleum hydrocarbons significantly (38%) compared to the control treatment. These results highlight the effectiveness of organic wastes as biostimulation agents in promoting the growth and reproduction of the soil microbial community, as well as establishing the bacterial inoculum.
显示更多 [+] 显示较少 [-]Bioremediation of 1,2-dichloroethane contaminated groundwater: Microcosm and microbial diversity studies
2015
Wang, S.Y. | Kuo, Y.C. | Huang, Y.Z. | Huang, C.W. | Kao, C.M.
In this study, the effectiveness of bioremediating 1,2-dichloroethane (DCA)-contaminated groundwater under different oxidation–reduction processes was evaluated. Microcosms were constructed using indigenous bacteria and activated sludge as the inocula and cane molasses and a slow polycolloid-releasing substrate (SPRS) as the primary substrates. Complete DCA removal was obtained within 30 days under aerobic and reductive dechlorinating conditions. In anaerobic microcosms with sludge and substrate addition, chloroethane, vinyl chloride, and ethene were produced. The microbial communities and DCA-degrading bacteria in microcosms were characterized by 16S rRNA-based denatured-gradient-gel electrophoresis profiling and nucleotide sequence analyses. Real-time polymerase chain reaction was applied to evaluate the variations in Dehalococcoides spp. and Desulfitobacterium spp. Increase in Desulfitobacterium spp. indicates that the growth of Desulfitobacterium might be induced by DCA. Results indicate that DCA could be used as the primary substrate under aerobic conditions. The increased ethene concentrations imply that dihaloelimination was the dominate mechanism for DCA biodegradation.
显示更多 [+] 显示较少 [-]Formulation of Green Bioactivator Based on Natural Products for Remediation of Polluted Waters
2021
Xu, Qiang | Xing, Hui | He, Chunling | Huang, Guangtuan
Bioactivator is a kind of agent rich in nutrients and a variety of active substances, which is considered as one of the green methods to deal with the pollution of natural waters because of its high efficiency, low cost, environment-friendly, and causing no secondary pollution. In this study, a green bioactivator formulation composed of fulvic acid, seaweed extract, and molasses (fulvic acid 1.744 mg/L: seaweed extract 1.756 mg/L: molasses 0.5 mg/L) was obtained by mixture design experiments, which can improve the removal rates of COD and NH₃-N by 15–25% and 7–15%, respectively, compared with untreated water. The effects of adding various carbon sources, trace elements, and growth factors on the basis of the developed formulation were explored to optimize the developed formulation and improve the effect of water remediation; the experiment results showed that sodium acetate and glucose as carbon sources were beneficial to the removal of NH₃-N; Mn, Mo, and B as trace elements can further increase the COD removal rates by 5.0–8.2%; niacin and vitamin B12 (VB12) as growth factors can increase COD removal rate by 7.5% and 4.7%, respectively. This study provides a green biological activator with good application prospect, which can be applied to the remediation of polluted water.
显示更多 [+] 显示较少 [-]Mechanism and Kinetics of Hexavalent Chromium Chemical Reduction with Sugarcane Molasses
2015
Chen, Zi-Fang | Zhao, Yong-Sheng | Zhang, Jia-Wen | Bai, Jing
Sugarcane molasses, which is a kind of microbial carbon source, is a viscous by-product of the refining of sugarcane into sugar. However, experiments were designed to ascertain the mechanism and kinetics of Cr(VI) reduction with sugarcane molasses without adding microbes in aqueous solution. Results indicated that sugarcane molasses can reduce Cr(VI) to Cr(III) at pH values that range from 2.0 to 6.1 when no bioreduction occurs in the reaction. Furthermore, the reaction mechanism was proven to be that Cr(VI) acts as an electrophile that readily accepts electrons from the phenolic hydroxyl group of plant polyphenol, and it is then reduced to Cr(III) and in the process oxidizes the phenolic hydroxyl group to a quinone. Meanwhile, the reaction could be described by the pseudo-first-order kinetic model with respect to Cr(VI) concentration. The reaction rate constants were 324.2, 65.9, 21.9, and 14.4 h⁻¹ when pH values were 2.0, 3.5, 5.0, and 6.1, respectively, at 20 °C. The k ₒbₛ increased 3.36, 7.02, and 13.48 times with the temperature adjusted from 5 to 10, 20, and 30 °C.
显示更多 [+] 显示较少 [-]Application of beet sugar byproducts improves sugar beet biofortification in saline soils and reduces sugar losses in beet sugar processing
2021
Alotaibi, Fahad | Bamagoos, Atif A. | Ismaeil, Fekry M. | Zhang, Wenying | Abou-Elwafa, Salah Fatouh
Improving the chemical and physical properties of saline soils is crucial for the sustainable production of sugar beet and efficient processing of beet sugar. Here, the impacts of the application of treated filter cake on sugar beet biofortification under saline soil and sugar losses into molasses during beet sugar processing were evaluated for the first time. The application of treated filter cake significantly reduced K%, Na%, and α-amino-N while enhanced sucrose content and quality index of beet root juice. Consequently, sugar loss percentage, sugar loss yield, and relative sugar loss yield were reduced, whereas recoverable sugar yield was enhanced. Linear regression analysis revealed that quality index and sugar loss yield were increased, whereas sugar loss percentage and relative sugar loss yield were reduced in response to the reduction of soil Na⁺ content accompanied with increasing Ca²⁺ content in the soil increased. The results provide treated filter cake as a promising amendment for saline soil remediation for improving biofortification of sugar beet and reducing sugar losses during beet sugar processing.
显示更多 [+] 显示较少 [-]Controlled release of molasses melanoidin-like product from hybrid organic–inorganic silica xerogels and its application to the phytoextraction of lead through the Indian mustard
2021
Hatano, Kenʼichi | Teraki, Minori | Nakajima, Daiki | Yamatsu, Takeshi
In this study, we investigate the release of melanoidin-like product (MLP) from hybrid silica xerogels to control the quantity of MLP in the medium for lead phytoextraction. In the preparation of the hybrid organic–inorganic xerogels with MLP, tetraethoxysilane (TEOS), methyltriethoxysilane (MTES), propyltriethoxysilane (PTES), and 3-aminopropyltriethoxysilane (APTES) were used as precursors. The experimental results suggest that the release of MLP can be easily controlled by partially substituting TEOS with the organosilanes. The addition of the organosilanes lowered the release rate of MLP in the following order of xerogels: TEOS, MTES/TEOS, PTES/TEOS, and APTES/TEOS. Furthermore, a novel phytoextraction of lead through the Indian mustard was conducted using the MLP-doped TEOS xerogel. Results show that the addition of TEOS xerogel did not have any influence on the growth of the mustard, whereas the lead uptake significantly increased in a nutrition medium with 1-mM Pb(NO₃)₂. In conclusion, the beneficial effect of the MLP-doped TEOS xerogel on lead phytoextraction was confirmed.
显示更多 [+] 显示较少 [-]Molasses melanoidin promotes copper uptake for radish sprouts: the potential for an accelerator of phytoextraction
2016
Hatano, Kenʼichi | Kanazawa, Kazuki | Tomura, Hiroki | Yamatsu, Takeshi | Tsunoda, Kin-ichi | Kubota, Kenji
Phytoextraction has been proposed as an alternative remediation technology for heavy metal contamination, and it is well known that chelators may alter the toxicity of heavy metals and the bioavailability in plants. Our previous work demonstrated that an adsorbent-column chromatography can effectively separate melanoidin-like product (MLP) from sugarcane molasses. The aim of this study was to examine the chelating property of MLP and to evaluate the facilitatory influence on the phytoextraction efficiency of Japanese radish. The result showed that MLP binds to all the metal ions examined and the binding capacity of MLP toward Cu²⁺ seems to be the highest among them. The metal detoxification by MLP followed the order of Pb²⁺ > Zn²⁺ > Ni²⁺ > Cu²⁺ > Fe²⁺ > Cd²⁺ > Co²⁺. Furthermore, in the phytoextraction experiment using copper sulfate, the application of MLP accelerated the detoxification of copper and the bioavailability in radish sprouts. Thus, these results suggest that MLP possesses the potential for an accelerator of phytoextraction in the copper-contaminated media.
显示更多 [+] 显示较少 [-]Biotreatment of Melanoidin-Containing Distillery Spent Wash Effluent by Free and Immobilized Aspergillus oryzae MTCC 7691
2013
Chavan, M. N. | Dandi, N. D. | Kulkarni, M. V. | Chaudhari, A. B.
A total of three fungal isolates from samples collected at spent wash disposal area were screened for their ability to degrade melanoidin. Distillery molasses spent wash was decolorized, and its chemical oxygen demand (COD) was reduced in immobilized fungal bioreactor (IFB) in the absence of carbon and nitrogen source using fungal mycelia of Aspergillus oryzae MTCC 7691. Fungal mycelia immobilized on baggase packed in a glass column under a batch-wise mode (1) effected removal of 75.71 +/- 0.12 % color, 51.0 +/- 0.13 % biological oxygen demand (BOD), 86.19 +/- 2.56 % COD, and 49.0 +/- 0.12 % phenolic pigments of distillery spent wash up to 25 days at 30 degrees C, while free fungal mycelia resulted in removal of 63.1 +/- 0.16 % color, 27.74 +/- 0.14 % BOD, 76.21 +/- 1.62 % COD, and 37.32 +/- 0.17 % phenolic pigments of distillery spent wash using shake flask, (2) manganese peroxidase (MnP) activity was highest (1.55 +/- 0.01 U ml(-1) min(-1)) in immobilized fungi, followed by lignin peroxidase (0.65 +/- 0.01 U ml(-1) min(-1)) and laccase activity (0.9 +/- 0.01 CU ml (1) min (1)), (3) accumulative MnP activity was highly correlated with (r=0.9216) spent wash decolorization and (r=0.7282) reduction of phenolic pigments, suggesting the presence of MnP activities in bioremediation of spent wash and (4) degradation of spent wash was confirmed by high-performance thin layer chromatography and gas chromatography-mass spectrometry analysis. Measurement of chlorophyll a content of Chlorella species cultivated on treated spent wash effluent obtained from immobilized fungal bioreactor was 5.16 +/- 0.71 mu g ml(-1) compared with 1.306 +/- 0.017 +/-mu g ml(-1) obtained with untreated spent wash. Thus, this work may provide a reasonable alternative for cost-effective bioremediation of distillery spent wash using immobilized A. oryzae on baggase fibers.
显示更多 [+] 显示较少 [-]An experimental study on eco-friendly and cost-effective natural materials for productivity enhancement of single slope solar still
2022
Natarajan, Sendhil Kumar | Suraparaju, Subbarama Kousik | Elavarasan, Rajvikram Madurai | Pugazhendhi, Rishi | Hossain, Eklas
The proposed research study aims to improve the productivity of solar still (SS) by using low-cost and eco-friendly materials. The aforementioned objective was achieved by enhancing the evaporation rate of seawater in the absorber basin and the condensation rate over the glass cover of the solar still. In this study, the low-cost and eco-friendly materials used for enhancing the evaporation rate in the solar still were molasses powder (MP), sawdust (SD) and rice husk (RH). In addition to these materials, bamboo straw (BS), banana leaf stem (BL) and rice straw (RS) were used as absorbing materials over the glass cover for enhancing the condensation rate. The experiments were carried out under similar meteorological conditions, and the results of the modified solar still were compared with the conventional solar still (CSS). The productivities of CSS, SSMP, SSRH, SSSD, SSBS, SSBL and SSRS were about 2250 mL/m², 2383 mL/m², 2467 mL/m², 3033 mL/m², 2700 mL/m², 2683 mL/m² and 3367 mL/m², respectively. The results of the experimental investigation highlighted that the SSSD had a comparatively better evaporation rate and 34.81% higher yield than CSS. Besides, SSRS had a comparatively better condensation rate and a 51.88% higher yield than CSS. Furthermore, the combination of sawdust (SD) and rice straw (RS) was investigated for the combined enhancement of evaporation and condensation. The solar still with sawdust and rice straw (SSSDRS) showed a 62.88% improvement in productivity with 3633 mL/m² when compared to CSS. Also, the economic analysis showed that the cost per litre (CPL) of freshwater obtained from SSSDRS was about ₹ 1.9 ($ 0.025) with a payback period of 4.4 months which was the least when compared to all the considered cases.
显示更多 [+] 显示较少 [-]Environmental and economic analysis of bioethanol production from sugarcane molasses and agave juice
2021
Parascanu, Maria Magdalena | Sanchez, Nestor | Sandoval-Salas, Fabiola | Carreto, Carlos Mendez | Soreanu, Gabriela | Sanchez-Silva, Luz
In this article, sugarcane molasses and agave juice were compared as potential feedstocks for producing bioethanol in Mexico in terms of their environmental impact and economic factors. Life cycle assessment (LCA) using SimaPro was carried out to calculate environmental impacts by using a cradle-to-gate approach. A preliminary economic analysis was performed to determine the economic feasibility of the studied options. Also, capital goods costs were obtained using the Aspen Plus economy package. Moreover, a sensitivity analysis was involved to compare the environmental and economic viability of producing bioethanol from sugarcane molasses and agave juice. LCA results revealed that cultivation and fermentation were the most harmful stages when producing bioethanol from sugarcane molasses and agave juice, respectively. Furthermore, when it was derived from agave juice rather than sugarcane molasses, it had more environmental benefits. This was ascribed to the lower consumption rate of fertilizers, pesticides, and emissions given off from the former. Regarding financial aspects, the preliminary analysis showed that producing bioethanol was not economically viable when grid energy alone was used. However, if power from the grid is partially replaced with renewable energy, producing bioethanol becomes economically feasible, and sugarcane molasses is the most suitable feedstock.
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