Journal of Environmental Chemical Engineering
·
2021
·
IF 5.909
Deyong Che,Liye Wang,Hongpeng Liu,Baizhong Sun,Shuai Guo
Biomass pyrolysis has attracted attention; however, its development has been restricted by the formation of NOx precursors, which result mainly from protein pyrolysis. In addition, the effect of lipids on this process is not clear. We extracted proteins and lipids from chlorella and sewage sludge to investigate the thermal decomposition characteristics, thermodynamic properties, kinetic parameters, and reaction mechanisms of protein with or without lipids. Two model-free methods Flynn-Wall-Ozawa (FWO) and Friedman (FM) were used to calculate the kinetic energy. Between 150 and 600 ℃, the average activation energy (E) of sludge protein was 73.63 kJ/mol (FM) or 72.53 kJ/mol (FWO), whereas with lipids, it was 129.19 kJ/mol (FM) or 124.55 kJ/mol (FWO), indicating that lipids restrict the pyrolysis of sludge protein. There was no significant difference between E of chlorella protein pyrolysis with or without lipids. Moreover, the proteins in sludge and chlorella released less NH 3 under the influence of lipids; however, the formation of HCN was affected slightly. The results of this study provide a reliable reference for the regulation of protein pyrolysis, considering the production of NOx precursors.
研究领域:
环境科学
·
生物能工程
✓ 已验证
产品关联
DOI
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2021
·
IF 6.291
Zezheng Wang,Dongdong Fu,Liu Gao,Huaiyuan Qi,Yuanyuan Su,Licheng Peng
Environmental aging of ubiquitous microplastics (MP) occurs through the action of biotic and abiotic factors, and aged MP exhibit different physicochemical properties and environmental behavior from virgin MP. This study aimed to investigate the aged micro-sized polystyrene (mPS) and polyvinyl chloride (mPVC), and the heavy metals copper (Cu) and cadmium (Cd), and examine the effects of their combined toxicities on microalga Chlorella vulgaris . Results showed that the presence of MP inhibited cell growth as compared with the control, the inhibition rate ( I ) decreased as concentrations of MP rose and aged MP exhibited stronger inhibition of cells than did virgin MP. The largest I was achieved in each culture with the MP concentration of 0.01 g/L, in which aged mPS with the maximal of 36.84% ( I aged mPS ) followed by aged mPVC ( I aged mPVC = 30.03%), virgin mPS ( I virgin mPS = 29.10%) and virgin mPVC ( I virgin mPVC = 16.72%). Addition of the heavy metals Cu 2+ and Cd 2+ significantly inhibited cell growth, and toxicity increased with concentrations in a range of 0.5–2.0 mg/L; the maximum I values were 19.50% ( I Cu ) and 85.14% ( I Cd ), respectively. The combined toxicity of aged MP + Cu or aged MP + Cd was less than that of individual heavy metals. In particular, as compared with the maximal I Cd of 85.14% achieved by single Cd 2+ , the toxicity of Cd 2+ was greatly reduced when combined with aged mPS and mPVC, with the I value decreased to 27.55% ( I aged mPS ) and 32.51% ( I aged mPVC ), respectively. Both single and combined treatments caused cell damage to the microalga, accompanied by increased superoxide dismutase (SOD) and intracellular malonaldehyde (MDA) content.
研究领域:
环境科学
·
毒理学
✓ 已验证
DOI
PubMed
高影响因子
Water
·
2022
·Vol. 14
·期 8
·1190
·
IF 3.53
Hao Li,Jin Wang,Yu Luo,Bo Bai,Fangli Cao
For improving the mechanical strength of controlled release fertilizer (CRF) hydrogels, a novel material ofChlorellawas employed as a bio-based filler to prepare chitosan–chlorella hydrogel beads with physical crosslink method. Here, the synthesis mechanism was investigated, and the chitosan–chlorella hydrogel beads exhibited enhanced mechanical stability under centrifugation and sonication than pure chitosan hydrogel beads.Chlorellabrought more abundant functional groups to original chitosan hydrogel, hence, chitosan–chlorella hydrogel beads represented greater sensitivity and controllable response to external factors including pH, salt solution, temperature. In distilled water, the hydrogel beads with 40 wt%Chlorellareached the largest water absorption ratio of 42.92 g/g. Moreover, the mechanism and kinetics process of swelling behavior of the chitosan–chlorella hydrogel beads were evaluated, and the loading and releasing of humic acid by the hydrogel beads as a carrier material were pH-dependent and adjustable, which exhibit the potential of chitosan–chlorella hydrogel beads in the field of controlled release carrier biomaterials.Keywords:hydrogel;controlled release;swelling;Chlorella;pH sensitivity
研究领域:
材料科学
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环境科学
·
农业
✓ 已验证
产品关联
DOI
高影响因子
Algal Research-Biomass Biofuels and Bioproducts
·
2021
·
IF 4.401
Pingkang Qian,Kun Gao,Zheng Gao,Chunye Xue,Xiaoli Hu,Qiaoqiao Liu,Jingwei Dong,Xiangyuan Deng
The aim of this work was to investigate the effects of myo -inositol (MI) on growth, photosynthetic activity , and chemical compositions of Chlorella sorokiniana . Results showed that a maximum value of cell density was obtained when this alga was cultivated in BG11 media with 1000 mg L −1 MI, which was 1.37 times greater than that in the controls. Moreover, it was observed that MI had a negative effect on algal photosynthetic activity, which could be alleviated by regulating the contents of chemical compositions, such as chlorophyll a (Chl a ). In the BG11 media with MI, contents of Chl a in the algal cells were in the range of 0.30–0.35 μg 10 −6 cells, which were about 1.75 times greater than that in the controls during microalgae cultivation. The accumulated Chl a would be used to capture and deliver more photons during algal photosynthesis . In addition, contents of lipids , carbohydrates, and proteins varied with the changes in MI concentrations. Thus, it is concluded that MI could promote the algal growth and play an important role in regulating the biochemical compositions in algal cells. These data would provide basic theory and technical support for large-scale cultivation and biomass production of microalgae by adding MI to culture media.
研究领域:
水生生物学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL GEOLOGY
·
2020
·
IF 3.363
Weiyan Que,Bihe Wang,Feili Li,Xiujuan Chen,Hui Jin,Zanfang Jin
The accumulation of heavy metals by freshwater algae becomes more complex in the presence of dissolved organic matter but it is unclear how and to what extent. In this study, we comparatively assessed the effects of malic acid and citric acid on the bioaccumulation of Pb by Chlorella pyrenoidosa . A 6 h exposure experiment showed that adding organic acid (OA) to an algae–Pb binary system prolonged the adsorption equilibrium time and that the extended time was related to the concentration and number of carboxyl groups of the OA. A pseudo-second-order model fit the kinetic data well in the presence of OAs. The normality of carboxyl groups was negatively correlated with the bioaccumulation rate, k 2 , but positively correlated with the maximum bioaccumulation capacity, q max , of Pb following a linear equation, Y = 121.3x + 52.2, R 2 = 0.9877. Neither the Freundlich model nor the Langmuir model could fit the isotherm data in the presence of OA, suggesting that a new mechanism might exist. The quantitative relationship between bioaccumulated Pb and carboxyl group of OA indicated a stoichiometric relationship, which seemed to support the theory of a ternary complex of Pb, OA, and algal surface. Our results have added clarity to the current understanding of the accumulation of heavy metals by algae in freshwater ecosystems .
研究领域:
环境科学
·
水生生物学
✓ 已验证
DOI
高影响因子
Carbon Neutralization
·
2024
·
IF 0
Hua-Wei Guo,Ya-Jun Wang,Huan Liu,Ya-Nan Zeng,Wei-Jie Wang,Tian-Ji Liu,Le-Le Kang,Rui Ji,Yi-Tong Wang,Jun-Guo Li,Zhen Fang
Metallurgical slag such as solid waste generated in the steel industry carries environmental pollution risks, but it is rich in nutrients required by microalgae. Metallurgical slag used for carbon capture and biomass energy conversion has multiple benefits: (i) reduction and harmless treatment of metallurgical solid waste, (ii) assisting in carbon neutrality by efficient carbon fixation, and (iii) production of biodiesel from CO 2 . In this study, AOD, BOF, BFS, HVS, and VTS slag were applied to culture Chlorella pyrenoidosa ( C. pyrenoidosa ) with the regulation of growth, carbon fixation, and lipid synthesis. An excellent fixed amount of CO 2 with 94.59 mg is obtained from C. pyrenoidosa biomass at BOF slag added (mass ratio of CO 2 captured/microalgae/slag with 1.99/1.00/10.53) since high Ca/Mg mass ratio of 419 (8.38 mg/L Ca and 0.02 mg/L Mg), no Cr and low concentration of Al (0.04 mg/L) contribute to regulating antioxidant enzyme activity (SOD and POD) to resist ROS and improving PEPC activity to reduce carbon flux toward lipid to promote biomass synthesis. Both metal concentrations from Ca (5.86 mg/L), Mg (0.05 mg/L), Al (0.42 mg/L), and Cr (0.006 mg/L) and suitable pH (10.53) in AOD leaching solution at solid/liquid ratio of 0.5 g/L change carbon flow toward efficient lipid synthesis (47.07 wt%) by continuously providing raw materials and energy by regulating ACC, ME, and PEPC activities. High value-added biodiesel with high concentrations of C16 and C18 methyl esters from lipid of C. pyrenoidosa is achieved, following other ecological and economic benefits including 197 mg CO 2 captured and 2198 mg AOD applied with harmless. In this study, C. pyrenoidosa is cultured with elements from metallurgical slag solid waste, which promotes C. pyrenoidosa efficient carbon fixation to assist in carbon neutrality, and provides guidance for CO 2 conversion to high-value-added products with low cost.
研究领域:
环境科学
·
能源工程
·
生物技术
·
材料科学
✓ 已验证
DOI
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2020
·
IF 4.872
Wenfeng Yang,Xinxin Gao,Yixiao Wu,Liang Wan,Lichen Tan,Shaoman Yuan,Huijun Ding,Weihao Zhang
Microplastics and nonylphenol (NP) are considered as emerging pollutant and have attracted wide attention, while their combined toxicity on aquatic organisms is barely researched. Therefore, the combined toxicity influence of NP with three types of microplastics containing polyethylene (PE1000, 13 μm and PE, 150 μm), polyamide (PA1000, 13 μm and PA, 150 μm) polystyrene (PS, 150 μm) on microalgae Chlorella pyrenoidosa was analyzed. Both growth inhibition, chlorophyll fluorescence, superoxide dismutase (SOD), malondialdehyde (MDA), and catalase (CAT) were determined. We found that single microplastics and NP both inhibited algal growth, thereby causing oxidative stress . The order of inhibition effect in single microplastics experiment was PE1000 > PA1000 > PE ≈ PS > PA. The combined toxicity experiment results indicated that the presence of microplastics had positive effect in terms of alleviating NP toxicity to C. pyrenoidosa , and the microplastics adsorption capacity to NP was the dominant contributing factor for this effect. According to the independent action model, the combined toxicity was antagonistic. Because the negative effect of smaller size microplastics on algal growth was aggravated with prolonged exposure time, the optimum effect of microplastics alleviated NP toxicity was PA1000 at 48 h, while this effect was substituted by PA at 96 h during combined toxicity. Thus, the toxicity of smaller size microplastics has a nonnegligible influence on combined toxicity. This study confirms that microplastics significantly affected the toxicity of organic pollutants on microalgae. Further research on the combined toxicity of smaller size microplastics with pollutants in chronic toxicity is needed.
研究领域:
环境科学
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毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
International Journal of Environmental Research and Public Health
·
2023
·Vol. 20
·期 4
·3623
·
IF 4.614
Junrong Li,Yingjun Wang,Ziqi Fan,Panyang Tang,Mengting Wu,Hong Xiao,Zhenxing Zeng
Antibiotics have become a new kind of organic pollutant as they are widely used in the water environment of China. Tetracycline (TC) is a class of broad-spectrum antibiotics produced or semi-synthesized by actinomycetes. Metronidazole (MTZ) is the first generation of typical nitroimidazoles. The content of nitroimidazoles is relatively high in medical wastewater, and their ecotoxicity is worthy of attention because they are difficult to completely eliminate. In this paper, the effects of TC and MTZ on the growth, cell morphology, extracellular polymer and oxidative stress ofChlorella pyrenoidosa(C. pyrenoidosa) were studied, and the toxic interactions between TC and MTZ mixture components were analyzed. The results showed that the 96h-EC50of TC and MTZ was 8.72 mg/L and 45.125 mg/L, respectively. The toxicity of TC toC. pyrenoidosawas higher than that of MTZ, and the combined toxicity effect of TC and MTZ was synergistic after the combined action of a 1:1 toxicity ratio. In addition, the algal cells ofC. pyrenoidosadied to varying degrees, the membrane permeability of algal cells was increased, the membrane was damaged, the surface of algal cells exposed to higher concentration of pollutants was wrinkled, and their morphology was changed. The extracellular polymer ofC. pyrenoidosawas affected by a change in concentration. The effect of pollutants on the reactive oxygen species (ROS) level and malondialdehyde (MDA) content ofC. pyrenoidosaalso had an obvious dose–effect relationship. This study contributes to the assessment of the possible ecological risks to green algae due to the presence of TC and MTZ in aquatic environments.Keywords:tetracycline;metronidazole;Chlorella pyrenoidosa;single toxicity;combined toxicity
研究领域:
环境科学
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2024
·Vol. 31
·期 26
·38274-38287
·
IF 0
Yang Lei,Li Yucai,Li Xiaotong,Lu Haoqi,Wang Yuchao,Meng Hongyan,Ren Yongxiang,Lan Jun
With the wide application of nanomaterials, the concentration of nanomaterials in natural water continues to increase, which poses a severe threat to the water environment. However, the influence of organic matter and nanomaterials rich in natural water on the toxic effect of algae growth is still unclear. In this study, the effects of humic acid (HA) and nano-cerium oxide (nCeO 2 ) on the physiology and transcriptome of Chlorella sp. were analyzed, and the mechanism of the toxic effect of HA on Chlorella sp. under nCeO 2 stress was revealed. Under 20–200 mg/L nCeO 2 stress, the growth of Chlorella cells was inhibited and the highest inhibition rate reached 52% within 200 mg/L nCeO 2 . The Fv/Fm and ETRmax values of Chlorella sp. decreased from 0.490 and 24.45 (20 mg/L nCeO 2 ) to 0.488 and 23.4 (100 mg/L nCeO 2 ), respectively. Under the stimulation of nCeO 2 , the level of reactive oxygen species in algal cells was increased, accompanied by lipid peroxidation and membrane damage. However, the addition of HA at concentrations of 5–10 mg/L effectively alleviated the toxic effect of nCeO 2 on Chlorella sp. Transcriptome analysis showed that 10 mg/L HA could alleviate the cellular stress at 100 mg/L nCeO 2 on Chlorella sp. by regulating genes related to photosynthesis and metabolism pathways. Moreover, the downregulation of genes (e.g., Lhca1, Lhcb1, AOC3, and AOC2) indicated that HA reduced the level of oxidative stress in Chlorella sp. These findings offer novel insights of evaluating the ecotoxicity nCeO 2 and HA in natural water environment and their impact on Chlorella sp. Graphical abstract
研究领域:
环境科学
·
毒理学
·
植物学
✓ 已验证
产品关联
DOI
PubMed
ENVIRONMENTAL POLLUTION
·
2019
·
IF 5.714
Zhiguang Niu,Wei’an Xu,Jing Na,Zhiwei Lv,Ying Zhang
Antibiotics have been widely detected in the ocean and have various impacts on the environment, while knowledge of their chronic influence on phytoplankton , especially red tide algae, is still limited. Dinoflagellates and green algae are common phytoplankton in marine ecosystems . The former is the main red tide algae, and the latter is an important primary producer. We investigated the long-term responses of two representative algae, Prorocentrum lima and Chlorella sp., to two common antibiotics (sulfamethoxazole (SMX) and norfloxacin (NFX)) at environmentally relevant levels (10 and 100 ng/L) during simulated natural conditions. The cell density and activities of three antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD)) were analyzed. The results showed that the influence of each antibiotic on Chlorella sp. was not significant ( p > 0.05) during the first 10 days, but the influence of the antibiotics later began to show significant inhibition ( p < 0.05) compared with the control group, especially during mixed exposure. P. lima was not inhibited, but its cell density increased. SMX had a superior stimulation effect on P. lima . The three enzymes activities of P. lima increased, and the antioxidant mechanism was not seriously impacted. However, for Chlorella sp., the activity of SOD increased while the activities of CAT and POD decreased, suggesting that this algae’s antioxidant system was unbalanced due to oxidative stress . Based on our results, the growth of P. lima was different from green algae Chlorella sp. as well as other inhibited marine algae (such as diatom, golden algae) studied in previous studies. Therefore, as a typical pollutant in the ocean, antibiotics may play a positive role in the bloom of dinoflagellate red tides.
研究领域:
海洋生物学
·
环境科学
✓ 已验证
DOI
高影响因子
AQUATIC TOXICOLOGY
·
2025
·
IF 4.3
Feifan Wu,Xiangjie Pan,Yuhao Zhou,Yan Zhu,Kai Liu,Wei Li,Jiangang Han
Emerging pollutants such as antibiotics have raised great concern in recent years, but the complex coexistence of multiple antibiotics in the environment poses a new challenge in the accurate assessment of the toxicity of antibiotics to aquatic organisms such as microalgae. In this study, the mechanism of action of a combination of erythromycin (ERY) and roxithromycin (ROX) on Chlorella pyrenoidosa was illustrated based on the physiological–biochemical response and transcriptomic analysis. The results revealed an inhibitory effect on the biomass of C. pyrenoidosa at 14 d in all treatment groups, whereas an antagonistic effect was observed in the coexposure groups. The photosystem was the main target despite the existence of multiple compensatory mechanisms, such as expanding the antenna size and initiating alternative electron carriers. The intercept of electrons on the donor side of PSI limited the production of energy, whereas the adjustment of the content and ratio of pigments strengthened microalgal adaptation. Enzymes and genes related to the degradation of exogenous compounds, including cytochrome P450 (P450), glutathione S-transferase (GST) and ABC transporters, mediated the detoxification of antibiotics. The upregulated expression of related genes induced by coexposure increased resistance and explained the antagonistic effects. The shift in energy allocation by increasing the proportion of lipids met the urgent requirements of microalgal physiological activities. This study reemphasizes the modes of interactions between multiple antibiotics and provides new insights into the mechanisms of antagonism induced by combinations of antibiotics.
研究领域:
环境科学
·
毒理学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Processes
·
2024
·Vol. 12
·期 5
·905
·
IF 2.8
Tianji Liu,Huawei Guo,Qing Yu,Yajun Wang,Huan Liu,Yanan Zeng,Yitong Wang,Chunyu Liu,Junguo Li
In this study,Chlorella pyrenoidosawas cultured with different concentrations of Cr(III) and Cr(VI), and the changes in biomass, lipid content, protein content and total sugar content ofChlorella pyrenoidosaunder different culture conditions were detected. The effects of Cr(III) and Cr(VI) on the intracellular antioxidant system and related key enzymes of lipid synthesis were analyzed. The results showed that appropriate Cr(III) and Cr(VI) concentrations could makeChlorella pyrenoidosaregulate the contents of SOD, POD, ASA, CAT and GSH in cells, improve the enzyme activity of ACC and promote lipid synthesis. The aim was to investigate the mechanism of lipid synthesis by analyzing the distribution of Cr(III) and Cr(VI) in algal cells. The lipid content ofChlorella pyrenoidosareached its highest level at 50.43 wt% and 38.00 wt% when both Cr(III) and Cr(VI) concentrations in the culture environment were 0.5 mg/L. These values were 1.37 and 1.03 times higher than the control group, respectively. The addition of appropriate Cr(III) and Cr(VI) concentrations can increase ME enzyme activity and decrease PEPC enzyme activity, shorten the biomass accumulation cycle and prolong the lipid synthesis cycle.
研究领域:
环境科学
·
生物化学
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）