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1.
Two living Chlorella species were used to remove nickel from solution containing 30 micrograms Ni ml-1 in 10 successive cycles. The present study also examined the continued viability of these two algal species after repeated exposure to nickel. The two species of Chlorella were Chlorella vulgaris (commercially available) and WW1 (indigenous species isolated from domestic sewage and was tentatively identified as Chlorella miniata). The nickel removal percentage of WW1 cells was maintained at around 85% in the first five cycles, then declined slightly from the fifth cycle onwards, and finally achieved around 70% removal at the end of the 10th cycle. On the contrary, the removal efficiency of C. vulgaris declined from 50 to 30% during the 10 cycles of nickel bisorption. At the end of these 10 successive cycles, WW1 accumulated a substantial amount of Ni2+ (the cumulative cellular Ni concentration was 0.92% dry w.), while the value was only 0.17% in the case of C. vulgaris. These results suggest that the local isolate, WW1, had more consistent and satisfactory ability for removing Ni than the commercial C. vulgaris. Both algal species were still capable of dividing after each nickel treatment cycle, suggesting that the cells were not killed even when significant amounts of nickel were adsorbed/absorbed. However, Ni exposure adversely affected the physiological activity of algal cells as reflected by the decline in division rate and chlorophyll-a activity in both species. Such negative effects became more obvious as the number of cyclic treatments was increased. Nevertheless, WW1 cells appeared to recover from nickel treatment when re-cultivated in commercial medium for 2 weeks. 相似文献
2.
Effects of propanil, tebufenozide and mefenacet on growth of four freshwater species of phytoplankton: a microplate bioassay 总被引:3,自引:0,他引:3
The Albufera Natural Park situated in Valencia (Spain), with a very rich flora and fauna is surrounded by rice fields in which pesticide spraying is a regular practice. With this in mind, the sensitivity of four algal species, Scenedesmus acutus, Scenedesmus subspicatus, Chlorella vulgaris and Chlorella saccharophila to pesticides propanil, tebufenozide and mefenacet was studied using single species toxicity tests. Organisms were exposed to different concentrations of these herbicides and the algal growth was measured in a microplate reader at 410 nm, at 0, 24, 48 and 72 h. Tebufenozide appeared to be the most inhibitory to Scenedesmus and Chlorella species growth. 72 h EC50 of propanil, tebufenozide and mefenacet ranged from 0.29 to 5.98 mg/l, 0.12 to 0.15 mg/l and from 0.25 to 0.67 mg/l, respectively for the four algal species. The two species of Chlorella were more tolerant than the two species of Scenedesmus. 相似文献
3.
Effects of bensulfuron-methyl and cinosulfuron on growth of four freshwater species of phytoplankton 总被引:5,自引:0,他引:5
The acute toxicity of sulfonylurea herbicides bensulfuron-methyl and cinosulfuron was tested on the five species of freshwater phytoplankton: Scenedesmus acutus, Scenedesmus subspicatus, Chlorella vulgaris and Chlorella saccharophila. Herbicide concentrations eliciting a 50% growth reduction over 96 h (EC50) ranged from 8 to 104 mg/l for cinosulfuron and from 0.015 to 6.2 mg/l for bensulfuron-methyl. The pesticides bensulfuron-methyl, atrazine and benthiocarb were more toxic than cinosulfuron, chlorsulfuron, molinate, fenitrothion and pyridaphenthion in a toxicity study with the same algal species. The transformation of effective concentrations of bensulfuron-methyl and cinosulfuron and other pesticides, obtained from toxicity measurements, into percent of the saturation level in water is used as a first evaluation of potential hazard to aquatic systems. The herbicides cinosulfuron, methyl-bensulfuron, atrazine and chlorsulfuron were more dangerous than the herbicides benthiocarb and molinate and than the insecticides fenitrothion and pyridaphenthion, in a study of hazard evaluation. The two species of Chlorella were more tolerant to both herbicides than the two species of Scenedesmus. A potential environmental hazard of sulfonylurea herbicides to aquatic systems has to be expected even at low environmental concentrations. 相似文献
4.
Xu Han Yuk Shan Wong Ming Hung Wong Nora Fung Yee Tam 《Water environment research》2008,80(7):647-653
The feasibility of obtaining and using the biomass of a microalga, Chlorella miniata, from domestic wastewater (DW) cultures for the removal of chromium(III) [Cr(III)] and chromium(VI) [Cr(VI)] was compared with that from commercial Bristol medium (BM). Results showed that Chlorella miniata cultured in DW under 16-8 hours light-dark cycle [DW(16-8)] had similar growth to that in BM [BM(16-8)], but these two biomass had different biochemical compositions, and the former one had lower carbohydrate and higher protein content. When cultured in domestic wastewater, a higher biomass was obtained under continuous illumination [DW(24-0)], and the cells had higher carbohydrate and lower protein concentrations than that of DW(16-8). The spectra of the Fourier transform infrared spectrometer revealed that the functional groups on the surface of the three kinds of biomass--DW(16-8), DW(24-0), and BM(16-8)--were comparable, except an additional peak at 1731 cm(-1) was found in the biomass cultured in domestic wastewater, which was probably the result of bacterial contamination. Although biochemical differences were found among the three kinds of microalgal biomass, similar biosorption performances to chromium pollutants were recorded, with approximately 75% Cr(III) and 100% Cr(VI) removed at equilibrium in Cr(III) and Cr(VI) experiments, respectively, when dead biomass was used as a biosorbent. Therefore, it is possible to culture Chlorella miniata in domestic wastewater and use the biomass for the removal of chromium pollutants. 相似文献
5.
Baglieri Andrea Sidella Sarah Barone Valeria Fragalà Ferdinando Silkina Alla Nègre Michèle Gennari Mara 《Environmental science and pollution research international》2016,23(18):18165-18174
Environmental Science and Pollution Research - This work evaluates the possibility of cultivating Scenedesmus quadricauda and Chlorella vulgaris microalgae in wastewater from the hydroponic... 相似文献
6.
根据城市二级出水水质特性,选择4 种不同氮磷水平的二级出水作为培养基,研究纯培养与共培养下,椭圆小球藻(Chlorella ellipsoidea)和斜生栅藻(Scenedesmus obliquus)在不同初始氮磷浓度下的生长状况及脱氮除磷的能力。结果表明,纯培养条件下,椭圆小球藻在2#(TN=15.00 mg/L,TP=1.00 mg/L)实验组中生物量最高,斜生栅藻在4#(TN=10.00 mg/L,TP=0.20 mg/L)实验组中收获最大生物量,椭圆小球藻与斜生栅藻对TP均具有70%以上去除率。共培养下,3#(TN=15.00 mg/L,TP=0.50 mg/L)实验组收获最高生物量,斜生栅藻生物量均高于椭圆小球藻,表明斜生栅藻在共培养条件下更具有生长优势,培养基中TN、TP含量分别降至5.00 mg/L和0.05 mg/L以下。2种培养模式均可达到对二级出水的深度脱氮除磷。 相似文献
7.
Two different species of photosynthetic microalgae, Chlorella pyrenoidosa and Scenedesmus sp., were grown in settled and activated sewage filtrates at two different inoculum sizes, aimed to reduce nutrient load from wastewater. Higher growth rates were recorded in cultures with higher inoculum size, and algal cells usually grew better in settled sewage than in activated sewage. As algae started to grow and multiply, both nitrogen and phosphorus content in wastewater decreased significantly. The removal rate was rapid during the first week of growth and more than 2/3 of wastewater N and P was reduced. After the initial period, the removal rate slowed down. At the end of this study, more than 80% of total-P and inorganic N present in settled sewage were reduced but such removal efficiency was lower in activated sewage. In general, high inoculum size of algal cells provided more N and P removal than low inoculum, and Chlorella cells performed better than Scenedesmus. These results suggest that cultivation of Chlorella seems to be one of the feasible methods to reduce the amount of nitrogen and phosphorus entering the nearby coastal water, thus preventing the eutrophication problem. It is also clear that algal ponds with high inoculum size might be more suitable to be installed as a secondary rather than a tertiary treatment process. 相似文献
8.
利用经过处理的鸡场养殖废水、猪场沼液(简称猪沼)、池塘养殖废水和BG-11培养基分别培养斜生栅藻和普通小球藻,对比2种微藻在各培养液中的生长、对废水中氮磷的净化效果以及微藻油脂的积累情况。结果表明:经过23 d的培养,小球藻处理组中,小球藻+猪沼培养液中可收获藻粉0.353 1 g·L-1,小球藻+BG-11中可收获藻粉0.189 8 g·L-1,高于其他3种培养液中的收获量。栅藻处理组中,栅藻+BG-11中收获的藻粉最多,为0.168 5 g·L-1,其次为栅藻+猪沼培养液(0.131 1 g·L-1)。2种微藻对不同废水培养液的净化效果不同,但总体来说,栅藻和小球藻对总磷的去除效果最好,去除率在89.32%~98.69%。对硝氮的去除率也在60%以上。另外,利用猪沼培养的小球藻油脂含量最高,达到50.34%;培养的栅藻油脂含量与BG-11中相近,并高于其他培养液。因此,利用猪场沼液培养栅藻和小球藻具有可行性。 相似文献
9.
Removal of heavy metals from anaerobically digested sewage sludge by isolated indigenous iron-oxidizing bacteria 总被引:11,自引:0,他引:11
The removal of heavy metals (Cr, Cu, Zn, Ni and Pb) from anaerobically digested sludge from the Yuen Long wastewater treatment plant, Hong Kong, has been studied in a batch system using isolated indigenous iron-oxidizing bacteria. The inoculation of indigenous iron-oxidizing bacteria and the addition of FeSO4 accelerated the solubilization of Cr, Cu, Zn, Ni and Pb from the sludge. pH of the sludge decreased with an increase in Fe2+ concentrations and reached a low pH of 2-2.5 for treatments receiving both bacterial inoculation and FeSO4. After 16 days of bioleaching, the following heavy metal removal efficiencies were obtained: Cr 55.3%, Cu 91.5%, Zn 83.3%, Ni 54.4%, and Pb 16.2%. In contrast, only 2.6% of Cr, 42.9% of Cu, 72.1% of Zn, 22.8% of Ni and 0.56% of Pb were extracted from the control without the bacterial inoculation and addition of FeSO4. The residual heavy metal content in the leached sludge was acceptable for unrestricted use for agriculture. The experimental results confirmed the effectiveness of using the isolated iron-oxidizing bacteria for the removal of heavy metals from sewage sludge. 相似文献
10.
固定化菌藻系统对污水处理厂出水的深度处理 总被引:4,自引:1,他引:3
将海藻酸钠固定化活性污泥和小球藻制成颗粒小球,以自制的流化床反应器对重庆市某污水处理厂出水进行深度处理,探讨了系统对氨氮、TP、COD的去除效果,实验结果表明:在HRT=12 h,溶解氧浓度为3.0 mg/L左右,pH值为6.2至8.0之间,环境室温条件下,系统对氨氮、TP、COD均有较好的去除效果,系统稳定运行后对氨氮、TP、COD去除率基本维持在60%、60%和30%以上,出水氨氮、TP、COD浓度基本维持在8、0.5和40 mg/L以下,出水浓度达到了《城镇污水处理厂污染物排放标准》(GB 18918-2002)的一级A标准。这项研究显示固定化菌藻胶球系统在污水处理厂出水的深度处理中具有潜在的应用前景。 相似文献
11.
The distribution and chemical fractionation of heavy metals retained in mangrove soils receiving wastewater were examined by soil column leaching experiments. The columns, filled with mangrove soils collected from two swamps in Hong Kong and the People's Republic of China, were irrigated three times a week for 150 days with synthetic wastewater containing 4 mg l(-1) Cu, 20 mg l(-1) Zn, 20 mg l(-1) Mn and 0.4 mg l(-1) Cd. Soil columns leached with artificial seawater (without any heavy metals) were used as the control. At the end of the leaching experiments, soil samples from each column were divided into five layers according to its depth viz. 0-1, 1-3, 3-5, 5-10 and > 10 cm, and analyzed for total and extractable heavy metal content. The fractionation of heavy metals in the surface soil samples (0-1 cm) was investigated by the sequential extraction technique. In both types of mangrove soils, the surface layer (0-1 cm) of the columns receiving wastewater had significantly higher concentrations of total Cu, Cd, Mn and Zn than the control. Concentrations declined significantly with soil depth. The proportion of exchangeable heavy metals in soils receiving wastewater was significantly higher than that found in the control, about 30% of the total heavy metals accumulated in the soil masses of the treated columns were extracted by ammonium acetate at pH 4. The sequential extraction results show that in native mangrove soils (the soils without any treatment), the major portion of Cu, Zn, Mn and Cd was associated with the residual and precipitated fractions with very low concentrations in more labile phases. However, in mangrove soils receiving wastewater, a significantly higher percentage of Mn, Zn and Cd was found in the water-soluble and exchangeable fractions. Copper appeared to be more strongly adsorbed in mangrove soils than the other heavy metals. In general, heavy metal accumulation in the surface mangrove soils collected in Hong Kong was higher than those in the PRC, although the metals in the latter soil type were more strongly bound. These findings suggest that whether the heavy metal retained in managrove soils becomes a secondary source or a permanent sink would depend on the kinds of heavy metals and also the types of mangrove soils. 相似文献
12.
4种固定化藻类对污水中氮的净化能力研究 总被引:1,自引:0,他引:1
取培养至对数末期的藻,采用海藻酸钙凝胶包埋固定,对人工污水进行静态模拟净化试验,研究了蛋白核小球藻、鱼腥藻、双对栅藻和突变衣藻4种藻在固定和悬浮状态下,对污水中的氨氮和硝酸氮的净化效率以及藻类的生长特性。结果表明:固定化藻细胞比悬浮态藻细胞具有生长更趋于稳定、藻类的活性保持时间更长的优势。4种藻类中,小球藻和鱼腥藻在污水中的生长状况更好,较适宜采用海藻酸钙凝胶包埋固定化技术。实验第5 d时,固定化小球藻、鱼腥藻、双对栅藻和衣藻对NH3-N去除率分别为91.9%、84.8%、68.3%和51.2%;对NO-3-N的去除率分别为85.1%、100%、96.9%和65.9%。固定化小球藻对NH3-N的去除效果最好,而固定化鱼腥藻对NO-3-N的去除效果最好。因此,小球藻和鱼腥藻更适用于去除污水中的氮,具有很好的应用前景。 相似文献
13.
The glutathione-S-transferase (GST, EC 2.5.1.18) activities in different freshwater microalgal species, namely, Chlorella vulgaris, Scenedesmus quadricauda, Scenedesmus platydiscus and Selenastrum capricornutum under the control condition (without pyrene addition) and at different pyrene concentrations were compared. During 7-days incubation under the control condition (without pyrene addition), all microalgal species exhibited measurable GST activities but the activities varied significantly among species and the difference could be more than 100-fold. The addition of pyrene at concentrations ranged from 0.1 to 1.0 mg l(-1) to microalgal cultures led to changes in GST activities but the patterns of changes varied from species to species. Among the four species, remarkably decreases in GST activities were found in S. quadricauda, a species most sensitive to pyrene toxicity, at high pyrene concentrations. On the contrary, GST activities in S. platydiscus and Se. capricornutum increased significantly as pyrene concentrations increased. These two species were found to be more resistant to pyrene and had higher efficiencies in metabolising pyrene than other species. C. vulgaris did not show any significant change in their GST activities with the addition of pyrene, and pyrene was not metabolised by this species. These results suggest that pyrene-induced changes of GST activities in microalgae might be related to their resistance and their ability to metabolise pyrene. In general, the pyrene-induced changes of GST activities were higher at 4-days than at 1- and 7-days incubation in all microalgae. 相似文献
14.
垃圾渗滤液是一种成分复杂、毒性较强且难处理的废水之一。实验采用混凝沉淀-厌氧-电解-好氧一体化组合工艺处理垃圾渗滤液,探索了混凝沉淀池和电解池的运行参数对垃圾渗滤液处理效果的影响,并分析了组合工艺对于6种重金属(Cu、Zn、Cd、Cr和Ni)的去除效果。实验结果表明,以PAC为混凝剂PAM为助凝剂时,投加量分别为1.2 g/L和1 mg/L,COD去除率可达57%。电化学工艺阶段,在pH为6.0,电流密度15 mA/cm2,Cl-浓度2 200~2 400 mg/L,电解2.5 h,垃圾渗滤液的COD去除率达55.4%。一体化电生物滤池对于重金属的去除具有明显的效果,Cu、Cd和Zn去除率达100%,Ni去除率超过90%,Cr去除率超过80%,COD整体去除率达94%;NH4+-N去除率达97.2%;TN去除率达73.6%。混凝沉淀-厌氧-电化学-好氧的组合工艺来处理垃圾渗滤液,能够有效地去除水体中的重金属及COD、NH4+-N。 相似文献
15.
电混凝处理电镀综合废水 总被引:4,自引:0,他引:4
采用电混凝法处理酸性电镀综合废水,首先研究了不同电流密度对总氰化物、重金属和化学需氧量(COD)去除率的影响。实验结果表明,电混凝可有效去除酸性电镀综合废水中的氰化物与重金属。随着电流密度的增大,总氰化物与重金属的去除率逐渐提高。当电流密度为10mA/cm2时,废水中残留的总氰化物、Cu2+、Ni2+、Cr6+和Zn2+ 的浓度分别为23.0、25.0、4.5、0.2和0.2mg/L。为了进一步提高去除率,在电化学体系中添加H2O2,随着H2O2投量的增大,总氰化物、重金属、COD去除率不断提高。当H2O2投量为3mL/L时,处理过废水中残留总氰化物、Cu2+、Ni2+、Cr6+、Zn2+和COD的浓度分别为0.2、2.0、3.0、1.5、0.1和220mg/L。 相似文献
16.
3种载体固定化菌藻共生系统脱氮除磷效果的对比 总被引:1,自引:0,他引:1
采用3种不同载体(海藻酸钠、聚乙烯醇、复合载体),分别将小球藻和栅藻与活性污泥固定成菌藻共生系统,制成菌藻凝胶小球,单独菌、单独藻的凝胶小球,用于处理人工污水。结果表明,(1)复合载体固定的菌藻共生系统氮磷去除效果最好,PVA载体的脱氮除磷效果次于复合载体优于海藻酸钠;(2)固定化菌藻共生系统的脱氮除磷效果明显优于单独固定菌和单独固定藻,固定菌的效果较差;(3)3种载体包埋下的固定化小球藻的脱氮除磷效果均较相同载体固定化的栅藻效果好。 相似文献
17.
Li H Yuan Y Shen C Wen Y Liu H 《Journal of environmental science and health. Part. B》2008,43(4):288-292
Enantioselectivity in the toxicity and degradation of the herbicide dichlorprop-methyl (2,4-DCPPM) in algal cultures was studied. Enantioselectivity was clearly observed in the toxicity of racemic 2,4-DCPPM and its two enantiomers. R-2,4-DCPPM showed low toxicity to Chlorella pyrenoidosa and Chlorella vulgaris, but higher toxicity to Scenedesmus obliquus. The observed toxicity was ranked: R-2,4-DCPPM>S-2,4-DCPPM>Rac-2,4-DCPPM; the toxicity of R-2,4-DCPPM was about 8-fold higher than that of Rac-2,4-DCPPM. Additionally, 2,4-DCPPM was quickly degraded, in the initial 12 h, and different algae cultures had different enantioselectivity for the 2,4-DCPPM enantiomers. There was no significant enantioselectivity for 2,4-DCPPM in Chlorella vulgaris in the initial 7 h. However, racemic 2,4-DCPPM was degraded by Scenedesmus obliquus quickly, in the initial 4 h, much quicker, in fact, than the S- or R-enantiomers (racemate>R->S-), indicating that the herbicide 2,4-DCPPM was absorbed enantioselectively by Scenedesmus obliquus. The rapid formation of 2,4-DCPP suggested that 2,4-DCPPM adsorbed by algal cells was catalytically hydrolyzed to the free acid, a toxic metabolite. The production rates of 2,4-DCPP were as follows: Scenedesmus obliquus>Chlorella pyrenoidosa>Chlorella vulgaris, consistent with the degradability of 2,4-DCPPM. Scenedesmus obliquus had quick, but different, degradative and uptake abilities for R-, S-, and Rac-2,4-DCPPM. The R- and S- enantiomers were not hydrolyzed in the first 12 h, while both enantiomers were hydrolyzed slowly after that. These results indicate that some physical and chemical properties of compounds are of importance in determining their enantioselective toxicity and degradation. The ester and its metabolite likely played an important role in enantioselective toxicity to the three algae. 相似文献
18.
Effects of 2,4-D, glyphosate and paraquat on growth, photosynthesis and chlorophyll-a synthesis of Scenedesmus quadricauda Berb 614 总被引:1,自引:0,他引:1
Wong PK 《Chemosphere》2000,41(1-2):177-182
The effects of 2,4-D, glyphosate and paraquat on growth, photosynthesis and chlorophyll-a synthesis by a freshwater green alga, Scenedesmus quadricauda Berb 614, were determined. These herbicides are the most often used in Hong Kong. Within the concentration range 0.02-200 mg/l, paraquat was more toxic than glyphosate and 2,4-D to the growth, photosynthesis and chlorophyll-a synthesis. The presence of 0.02, 0.2 or 2 mg/l of 2,4-D was not toxic to the alga. Algal growth, photosynthesis and chlorophyll-a synthesis were stimulated by the presence of low concentrations (0.02 or 0.2 and 0.02 mg/l, respectively) of 2,4-D and glyphosate. The presence of 0.02 or 0.2 mg/l of paraquat, 2 mg/l of glyphosate or 20 mg/l of 2,4-D was significantly inhibitory to the three test parameters, whereas the presence of 2 or more mg/l of paraquat, 20 or more mg/l of glyphosate or 200 mg/l of 2,4-D completely inhibited algal growth, photosynthesis and chlorophyll-a synthesis. The use of the alga as a bio-indicator of herbicide contamination in freshwater environment was discussed. 相似文献
19.
为了解2种新分离微藻的净化和资源化潜力,研究比较了其生长、氮磷去除和营养特性。结果表明,栅藻和月牙藻的最大生物量(干重)分别为0.78g/L和0.53g/L;最大生物量(干重)增长速率分别为0.05g/(L·d)和0.03g/(L·d)。培养至第23天,栅藻和月牙藻对TN的去除率分别为85.1%和72.5%;对TP的去除率为82.6%和79.7%,但栅藻较月牙藻更易释放较多的No2--N进入藻液。稳定期时,栅藻、月牙藻的粗蛋白质含量和粗蛋白产量(干重)分别为31.8%、19.2%和0.24g/L、0.09g/L;粗脂含量和粗脂产量(干重)分别为7.81%、9.26%和0.06g/L、0.05g/L。综上,与月牙藻相比,栅藻具有明显的生长、氮磷去除和营养优势,在进行水产养殖废水的净化和资源化利用上可作为优选藻种。 相似文献
20.
Assessment of metal and nutrient concentrations in river water and sediment collected from the cities in the Pearl River Delta,South China 总被引:17,自引:0,他引:17
The effects of anthropogenic activities, industrialization and urbanization on the accumulation of heavy metals and nutrients in sediments and water of rivers in the Pearl River Delta region were examined. Most sediments were seriously contaminated with Cd, Pb, and Zn in accordance with the classification by Hong Kong Environmental Protection Department. Total phosphorus (P) and nitrogen (N) concentrations in sediments ranged from 0.02% to 0.12% and 0.06% to 0.64%, respectively. High carbon (C), N, P and sulphur (S) levels at Yuen Long Creek were related to the discharge of industrial effluents along the river. The enrichment of P and ammoniacal-nitrogen (NH4+-N) in water were obvious. For most sites, the P concentration exceeded 0.1 mg/l, which is the recommended concentration in flowing water to encourage excessive growth of aquatic plants. Nine out of the 16 sites studied had NH4+-N concentration over 2 mg/l. The rivers in the south of Deep Bay (Hong Kong) had high nutrient exports compared with the rivers in the east region and western oceanic water. The concentrations of nitrate-nitrogen NO3--N in surface water were under the maximum contaminant level in public drinking water supplies (10 mg/l) except for one site. Although the concentrations of heavy metals in overlying water were low, their accumulations were significant. High contents of nickel (Ni) and zinc (Zn) in water were found at certain locations, suggesting the occurrence of some local contamination. These preliminary results indicated that river and sediment transported pollutants is likely one of the factors for the water quality degradation of Deep Bay water. 相似文献