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1.
Lab scale constructed wetlands were used to evaluate organic load removal efficiency. Bioreactors were fed with synthetic wastewater (SW) with varying concentrations of nitrogen and potassium. Reactors were planted with species Phragmites australis. Fed theoretic COD was adjusted to 240.0 mg-O2 L−1, nitrogen levels were 10 and 40 mg-N L−1 (ammonium sulfate), potassium levels were 5 and 31 mg-K L−1 (potassium monobasic phosphate). The higher biomass yield, for 0.5 and 0.775 N:K ratios, was related with higher organic load removal. The ratio N:K showed significant differences for organic load abatement, when 1:0.5 and 1:0.775 N:K ratios were applied, 96.8% efficiency was obtained, whereas N:K ratio of 1:0.125 had efficiency of 92.1% and N:K ratio of 1:3.1 showed an efficiency of 90.5%. For planted bioreactor EH decreased in 162.7 mV from sample port to 5 cm down to 35 cm depth, while for the bioreactor without plant showed an EH decrement of only 17.7 mV.  相似文献   

2.
Five different mesophilic systems were evaluated in this study for the anaerobic treatment of food waste. Systems A and B were one stage methane with unsonicated and sonicated feeds, respectively, while, systems C and D were two-stage hydrogen and methane with unsonicated and sonicated feeds, respectively. System E comprised a novel sonicated biological hydrogen reactor (SBHR) followed by methane reactor. The results showed that sonication inside the reactor in the first stage (system E) showed superior results compared to all other systems. Overall VSS removal efficiencies of 67%, 59%, 51%, 44%, and 36% were achieved in systems E, D, C, B, and A, respectively. Volumetric hydrogen production rates of 4.8, 3.3, and 2.6 L H2/Lreactor d were achieved in the SBHR, CSTR with and without sonicated feed, respectively, while, methane production rates of 1.6, 2.1, 2.3, 2.6, and 3.2 L CH4/Lreactor d were achieved in systems A-E, respectively.  相似文献   

3.
This study investigated three lab-scale hybrid wetland systems with traditional (gravel) and alternative substrates (wood mulch and zeolite) for removing organic, inorganic pollutants and coliforms from a synthetic wastewater, in order to investigate the efficiency of alternative substrates, and monitor the stability of system performance. The hybrid systems were operated under controlled variations of hydraulic load (q, 0.3-0.9 m3/m2 d), influent ammoniacal nitrogen (NH4-N, 22.0-80.0 mg/L), total nitrogen (TN, 24.0-84.0 mg/L) and biodegradable organics concentration (BOD5, 14.5-102.0 mg/L). Overall, mulch and zeolite showed promising prospect as wetland substrates, as both media enhanced the removal of nitrogen and organics. Average NH4-N, TN and BOD5 removal percentages were over 99%, 72% and 97%, respectively, across all three systems, indicating stable removal performances regardless of variable operating conditions. Higher Escherichia coli removal efficiencies (99.9%) were observed across the three systems, probably due to dominancy of aerobic conditions in vertical wetland columns of the hybrid systems.  相似文献   

4.
Reactive oxygen species are considered to play a role in the development of type 2 diabetes mellitus (T2DM) and its complications. 8-Oxoguanine, which is one of the major oxidation base lesions produced by reactive oxygen species, may cause G:C to T:A transversion mutations because it can mispair with adenine. hMTH1 (human mutT homolog 1), hOGG1 (human 8-oxoguanine glycosylase 1) and MUTYH (human mutY homolog) genes constitute the 8-oxoG repair pathway. In this study, we screened for the polymorphism variants Val83Met (c.247G>A, rs4866) in hMTH1; c.-53G>C (rs56387615), c.-23A>G (rs1801129) and c.-18G>T (rs1801126) in the 5′-UTR of hOGG1; and AluYb8 insertion in MUTYH (AluYb8MUTYH, rs10527342) and investigated their synergistic effect on the risk of T2DM in the Chinese population. The genotypes were determined by electrophoresis, a high-resolution melting technique and sequencing of PCR products. Our results showed that the c.247G>A variant in the hMTH1 gene increased the risk of T2DM in > 55 years of age groups (OR = 1.579; 95%CI: 1.029–2.421). The set of c.-53G>C, c.-23A>G and c.-18G>T variants detected in the 5′-UTR of the hOGG1 gene and the AluYb8 insertion in the MUTYH gene were each associated with an increased risk of T2DM (OR = 1.507, 95%CI: 1.122–2.024; OR = 1.229, 95%CI: 1.030–1.466, respectively). Combined analysis of the variations among the three genes suggested that the c.247G>A variant in hMTH1 combined with AluYb8MUTYH variant had a synergistic effect on increasing the risk of T2DM (OR = 1.635; 95%CI: 1.147–2.330). This synergy was also observed between the variants in the 5′-UTR of the hOGG1 and the AluYb8MUTYH variant (OR = 1.804; 95%CI: 1.254–2.595). Our results suggest, for the first time, the combined effects of AluYb8MUTYH with either hMTH1 c.247G>A or variants in the 5′-UTR of the hOGG1 on the risk of T2DM.  相似文献   

5.
The most common and widespread species of Nasturtium in central Europe are the tetraploid Nasturtium officinale (2n = 4x = 32), the octoploid Nasturtium microphyllum (2n = 8x = 64), and their hexaploid hybrid Nasturtium × sterile (2n = 6x = 48). For the first time, flow cytometry was used to measure the genome size (2C DNA content) of these taxa. The highest nuclear DNA content was found in the octoploid N. microphyllum (2C = 1.43 pg) and the lowest in the tetraploid N. officinale (2C = 0.76 pg). Some differences in the amount of nuclear DNA were observed for the hexaploid N. × sterile (2C = 1.09-1.12 pg). Genome size analysis was thus proposed as a very useful tool for the identification of species of Nasturtium in their vegetative stage.  相似文献   

6.
7.
An anaerobic digestion technique was applied to textile dye wastewater aiming at the colour and COD removal. Pet bottles of 5 L capacity were used as reactor which contains methanogenic sludge of half a liter capacity which was used for the treatment of combined synthetic textile dye and starch wastewater at different mixing ratios of 20:80, 30:70, 40:60, 50:50 and 60:40 with initial COD concentrations as 3520, 3440, 3360, 3264 and 3144 mg L−1, respectively. The reactor was maintained at room temperature (30 ± 3 °C) with initial pH of 7. The maximum COD and colour removal were 81.0% and 87.3% at an optimum mixing ratio of 30:70 of textile dye and starch wastewaters. Both Monod’s and Haldane’s models were adopted in this study. The kinetic constants of cell growth under Haldane’s model were satisfactory when compared to Monod’s model. The kinetic constants obtained by Haldane’s model were found to be in the range of μmax = 0.037-0.146 h−1, Ks = 651.04-1372.88 mg L−1 and Ki = 5681.81-18727.59 mg L−1.  相似文献   

8.
The surficial sediments recovered from 12 sites located near the channel axis of the Florida Straits and the lower slope off NW Cuba were analyzed for total organic carbon (TOC), nitrogen (TN), phosphorus (TP), elemental C:N:P ratios, C and N isotopic values, and 14C dating. The depth profiles of TOC, TN, and TP (0-18 cm) displayed a downcore trend and a significant variation. The TOC values were low (0.15 to 0.62%; 66 to 516 µmol g-1). Sites near the island’s lower slope had lower TOC average concentrations (158-333 µmol g-1) than those closer to the channel axis (averaging 341-516 µmol g-1; p <0.05). The TN concentrations near the lower slope attained 0.11% (80 µmol g-1), whereas, towards the channel axis, they decreased to 0.07% (55 µmol g-1; p<0.05). The C:N ratios ranged from 1.9 to 10.2. The mean molar C:N ratio (5.4) indicated a marine hemipelagic deposition. The TP was lower at sites near the lower slope (38.4 to 50.0 µmol g-1; 0.12% to 0.16%) than those near the channel axis (50.0 to 66 µmol g-1; 0.15 to 0.21%). C:P fluctuated from 7.7 to 14.1 in the surficial sediment layer. The bulk organic δ13Corg and δ15N values confirmed pelagic organic sources, and the 14C dating revealed that the sediments were deposited during the Holocene (1000-5000 yr BP). We suggest that the hydrodynamic conditions in the Straits influence vertical and advective fluxes of particulate organic material trapped in the mixed-layer, which reduces the particulate matter flux to the seabed.  相似文献   

9.
Plants have many well-documented influences in treatment wetlands, but differences in individual species’ effects on year-round and seasonal performance are poorly understood. In this study, we evaluated plant effects on seasonal patterns of organic carbon removal (measured as COD) and sulfate concentration (used as an indicator of rootzone oxidation) in replicated, batch-loaded, greenhouse microcosms simulating subsurface treatment wetlands. Microcosms were planted with monocultures of 19 plant species or left unplanted as controls, dosed every 20 days with synthetic secondary wastewater, and operated over 20 months at temperatures from 4 to 24 °C. Study-long COD removal averaged 70% for controls and 70-97% for individual species. Most species enhanced COD removal significantly and the benefits of plants were greatest at 4-8 °C because COD removal decreased at low temperatures in controls but displayed limited seasonal variation in planted microcosms. Removal was significantly better at 24 °C than 4 °C with two species (Panicum virgatum and Leymus cinereus), significantly poorer with two species (Carex utriculata and Phalaris arundinacea), and did not differ with 15 species. Only one species showed a significant positive correlation between temperature and COD removal (Iris missouriensis, r = 0.67), while two species showed significant negative correlations (better when colder: Carex nebrascensis, r = −0.67; C. utriculata, r = −0.93). High COD removal throughout the study was strongly associated with high SO4 concentrations at low temperatures, suggesting that plant performance is related to rootzone oxidation and species’ abilities to promote aerobic over anaerobic microbial processes, particularly in winter. Results indicate that improved year-round and cold-season COD removal is common across diverse wetland plant species and novel species can be as good or better than those typically used. Better performing species were largely in the sedge and rush families (Cyperaceae and Juncaceae), while poorer performing species were largely in the grass family (Poaceae).  相似文献   

10.
Low efficiency of dye removal by mixed bacterial communities and high rates of dye decolorization by white-rot fungi suggest a combination of both processes to be an option of treatment of textile wastewaters containing dyes and high concentrations of organics. Bacteria were able to remove mono-azo dye but not other chemically different dyes whereas decolorization rates using Irpex lacteus mostly exceeded 90% within less than one week irrespective of dye structure. Decolorization rates for industrial textile wastewaters containing 2-3 different dyes by fungal trickling filters (FTF) attained 91%, 86%, 35% within 5-12 d. Sequential two-step application of FTF and bacterial reactors resulted in efficient decolorization in 1st step (various single dyes, 94-99% within 5 d; wastewater I, 90% within 7 d) and TOC reduction of 95-97% in the two steps. Large potential of combined use of white-rot fungi and traditional bacterial treatment systems for bioremediation of textile wastewaters was demonstrated.  相似文献   

11.

Purpose

Matrix metalloproteinase (MMP) 1, MMP2, MMP3 and MMP9 are important members of the MMP family. Recently, many studies have been carried out on the association between polymorphisms of MMP1-1607 1G/2G, MMP2-735 C/T, MMP2-1306 C/T, MMP3-1171 5A/6A and MMP9-1562 C/T and lung cancer risk. However the results of these studies remained inconclusive due to conflicting results from different case–control studies. To clarify these associations, we conducted a meta-analysis.

Methods

We conducted a comprehensive search in Medline, EMBASE, OVID and Chinese Biomedical Literature Database (date from Jan 2000 to Aug 2012). Overall and subgroup analysis by the ethnicity of study population was carried out. Odds ratio (OR) with 95% confidence interval (95%CI) was used to assess the strength of the association.

Results

There were 17 studies involving five polymorphic sites in four MMP genes. For MMP1-1607,increased lung cancer risk was found under dominant model (MMP1-1607 1G/2G: OR = 1.14, 95%CI = 1.03–1.26, P = 0.01), but not in the Caucasian population. For MMP2-1306 C/T, T polymorphism decreased lung cancer risk under dominant and recessive models (dominant, OR = 0.63, 95%CI = 0.46–0.88, P = 0.0006; recessive, OR = 0.61, 95%CI = 0.38–0.99, P = 0.04). For MMP9-1562 C/T, TT genotype decreased this risk under the recessive model (OR = 0.38, 95%CI = 0.19–0.75, P = 0.005), but not in the Asian population. For MMP2-735 C/T and MMP3-1171 5A/6A, there was no association between this polymorphism and lung cancer risk under the dominant and recessive models.

Conclusions

MMP1-1607 1G/2G polymorphism increased lung cancer risk in Asians. It was also found thatMMP2-1306 C/T polymorphism decreased lung cancer risk in Asians, while MMP9-1562 C/T polymorphism decreased lung cancer risk in Caucasians. No significant difference was found in any genotype of MMP2-735 C/T and MMP3-1171 5A/6A. Further studies with larger sample sizes should be carried out.  相似文献   

12.
We report the homogeneous catalytic air oxidation of 1-hexene, cyclohexene and styrene using cis-[MoO2(hap-SBDTC)(solv)] (1b) and cis-[MoO2(hap-SMDTC)(solv)] (2b), where hap-SBDTC and hap-SMDTC are Schiff bases derived from o-hydroxyacetophenone (hap) and S-benzyldithiocarbazate (SBDTC) or S-methyldithiocarbazate (SMDTC), respectively. Both hap-SBDTC and hap-SMDTC are dissymmetric tridentate O,N,S-donor Schiff base ligands. The catalytic tests were performed in DMF solvent at 60 °C under 1 atm O2.The olefin conversion was determined using gas chromatography. The percentage conversion of the above-mentioned substrates at the end of 6 h was in the range 86-98%. The final oxidation products were found to be 1-hexanal for 1-hexene, styrene epoxide and phenyl acetaldehyde (81:19) for styrene and cyclohexene epoxide and 2-cyclohexen-1-ol (85:15) in the case of cyclohexene. The oxidation reaction typically followed pseudo-order kinetics; however, a two-stage first order reaction is evident with complex 2b. This is attributed to less steric and electron-donating methyl substitution on S in 2b that possibly imparted a higher reactivity accompanying the formation of an intermediate in a relatively faster reaction step prior to the formation of final oxidation products. A reaction mechanism that explains the experimental results is proposed.  相似文献   

13.

Purpose

Studies investigating the association between PTPN22 gene C1858T polymorphism and type 1 diabetes (T1D) susceptibility among Caucasian population have reported conflicting results. To investigate this inconsistency, we performed a meta-analysis of all available studies dealing with the relationship between the PTPN22 C1858T polymorphism and T1D.

Methods

Databases including PubMed, Web of Science, and EMBASE were searched to find relevant studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association.

Results

In total, 33 population-based studies with 22, 485 cases and 35, 292 controls, 9 family-based studies involving 7276 families were included. Under the random-effects model, the per-allele overall OR of the C1858T polymorphism for T1D was 1.89 (95% CI: 1.76–2.02, P < 10− 5) by pooling all available case–control studies. In addition, we found significant evidence for overtransmission of the risk T allele in family-based studies (overall OR TDT = 1.58, 95% CI: 1.43–1.74; P < 10− 5). The summary OR from case–control and family-based association studies was 1.81 (95% CI: 1.70–1.93, P < 10− 5).

Conclusions

In conclusion, this meta-analysis suggests that C1858T polymorphism in PTPN22 is associated with elevated T1D risk among Caucasian population.  相似文献   

14.
A swim-bed reactor for partial nitritation with polymeric coagulant treatment and an UASB reactor for anammox were applied to the treatment of livestock manure digester liquor. The partial nitritation was maintained for 32 days under a 1.6 kg N/m3/d nitrogen loading rate (NLR) with an average conversion efficiency of 51%, and achieved 1.65 kg N/m3/d of the maximum nitrite production rate under 2.58 kg N/m3/d of NLR. Although 200 mg/L of TOC remained in the effluent of the partial nitritation reactor, the anammox nitrogen removal rate was not significantly decreased and a relatively high rate of 2.0 kg N/m3/d was obtained under a NLR of 2.2 kg N/m3/d. 16S rRNA gene analysis showed that Nitrosomonas and KSU-1 were dominant in the partial nitritation and anammox reactor, respectively. The results of this study demonstrated that the partial nitritation-anammox process has possibility of applying to the nitrogen removal of livestock manure digester liquor.  相似文献   

15.
Hybrid constructed wetland systems have recently been used to treat wastewaters where high demand for removal of ammonia is required. However, these systems have not been used too often for small on-site treatment systems. This is because in many countries ammonia is not limited in the discharge from small systems. Hybrid systems have a great potential to reduce both ammonia and nitrate concentrations at the same time. In our study we employed a three-stage constructed wetland system consisting of saturated vertical-flow (VF) bed (2.5 m2, planted with Phragmites australis), free-drained VF bed (1.5 m2, planted with P. australis) and horizontal-flow (HF) bed (6 m2, planted with Phalaris arundinacea) in series. All wetlands were originally filled with crushed rock (4-8 mm). However, nitrification was achieved only after the crushed rock was replaced with sand (0-4 mm) in the free-drain wetland. Also, original size of crushed rock proved to be too vulnerable to clogging and therefore, in the first wetlands the upper 40 cm was replaced by coarser fraction of crushed rock (16-32 mm) before the second year of operation started. The system was fed with mechanically pretreated municipal wastewater and the total daily flow was divided into two batches 12 h apart. The evaluation of the results from the period 2007 to 2008 indicated that such a system has a great potential for oxidation of ammonia and reduction of nitrate. The ammonia was substantially reduced in the free-drained VF bed and nitrate was effectively reduced in the final HF bed. The inflow mean NH4-N concentration of 29.9 mg/l was reduced to 6.5 mg/l with the average removal efficiency of 78.3%. At the same time the average nitrate-N concentration rose from 0.5 to only 2.7 mg/l at the outflow. Removal of BOD5 and COD amounted to 94.5% and 84.4%, respectively, with respective average outflow concentrations of 10 and 50 mg/l. Phosphorus was removed efficiently despite the fact that the system was not aimed at P removal and therefore no special media were used. Phosphorus removal amounted in 2008 to 65.4%, but the average outflow concentration of 1.8 mg/l is still high. The results of the present study indicate very efficient performance of the hybrid constructed wetlands, but optimal loading parameters still need to be adjusted. The capital cost of the experimental system is comparable to the conventional on-site treatment plant but the operations and maintenance costs are about one third of the conventional plant.  相似文献   

16.
In this study, the performance of 5.4 L hybrid upflow anaerobic sludge blanket (HUASB) reactor for treating poultry slaughterhouse wastewater under mesophilic conditions (29-35 °C), was investigated. After starting-up, the reactor was loaded up to an OLR of 19 kg COD/m3 d and achieved varied TCOD and SCOD removal efficiencies of 70-86% and 80-92%, respectively. The biogas was varied between 1.1 and 5.2 m3/m3 d with the maximum methane content of 72%. The maximum methane yield was 0.32 m3/kg CODremoved at an OLR of 9.27 kg COD/m3 d. Black matured granules of size between 2.5 and 5 mm were observed at the end of 225 d operation. RTD study showed the flow behavior was in mixed regime at the end of performance study. Step wise polynomial regression analysis was fitted well. Methanobacterium and Methanosaeta bacteria were dominant at the end of start-up whereas Methanosarcina, Cocci and rods were predominant at the end of performance studies.  相似文献   

17.
The C3435T (rs1045642) polymorphism, located in multi-drug resistance gene 1 (MDR1), has demonstrated its role in decreasing the P-gp activity level which is related to the carcinogenesis. Many published studies have evaluated the association between the MDR1 C3435T polymorphism and breast cancer risk. However, the results remain conflicting rather than conclusive. To derive a more precise estimation of the association between MDR1 C3435T polymorphism and risk of breast cancer, we performed a meta-analysis comprised of 10 case–control studies, including 5282 breast cancer cases and 7703 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the strength of the association. The overall results indicated that the variant genotypes were associated with a significantly increased risk of breast cancer (TT versus CC: OR = 1.45, 95% CI = 1.14–1.30, TT versus CT/CC: OR = 1.13, 95% CI = 1.04–1.23, TT/CT versus CC: OR = 1.22, 95% CI = 1.02–1.46). Our results suggest that the MDR1 C3435T polymorphism may contribute to individual susceptibility to breast cancer.  相似文献   

18.
Phospholamban (PLN) is a dynamic single-pass membrane protein that inhibits the flow of Ca2+ ions into the sarcoplasmic reticulum (SR) of heart muscle by directly binding to and inhibiting the SR Ca2+ATPase (SERCA). The PLN monomer is the functionally active form that exists in equilibrium between ordered (T state) and disordered (R state) states. While the T state has been fully characterized using a hybrid solution/solid-state NMR approach, the R state structure has not been fully portrayed. It has, however, been detected by both NMR and EPR experiments in detergent micelles and lipid bilayers. In this work, we quantitatively probed the μs to ms dynamics of the PLN excited states by observing the T state in DPC micelles using CPMG relaxation dispersion NMR spectroscopy under functional conditions for SERCA. The 15N backbone and 13Cδ1 Ile-methyl dispersion curves were fit using a two-state equilibrium model, and indicate that residues within domain Ia (residues 1-16), the loop (17-22), and domain Ib (23-30) of PLN undergo μs-ms dynamics (kex = 6100 ±800 s- 1 at 17 °C). We measured kex at additional temperatures, which allowed for a calculation of activation energy equal to ∼ 5 kcal/mol. This energy barrier probably does not correspond to the detachment of the amphipathic domain Ia, but rather the energy needed to unwind domain Ib on the membrane surface, likely an important mechanism by which PLN converts between high and low affinity states for its binding partners.  相似文献   

19.
The application of n-alkanes as faecal markers to estimate diet composition of equines and cattle was studied. Twelve mature crossbreed mares (385 ± 47 kg live weight – LW) and six adult non-lactating cows (499 ± 36 kg LW) of Asturiana de los Valles breed were divided in groups of three animals (H1, H2, H3 and H4 in equines and C1 and C2 in cattle) and housed in individual stalls. Animals received a daily total amount of 1.0 kg DM/100 kg LW of different experimental diets composed of herbaceous (Lolium perenne L.) and woody species (Ulex gallii Planchon and heather: Erica spp. and Calluna vulgaris L.). Diet composition varied among treatments: H1 and C1 – L. perenne as sole component; H2 and C2 – L. perenne (0.70) and heather (0.30); H3 – L. perenne (0.70) and U. gallii (0.30); H4 – L. perenne (0.40), heather (0.30) and U. gallii (0.30).  相似文献   

20.
Serpins are a superfamily of structurally conserved proteins. Inhibitory serpins use a suicide substrate-like mechanism. Some are able to inhibit cysteine proteases in cross-class inhibition. Here, we demonstrate for the first time the strong inhibition of initiator and effector caspases 3 and 8 by two purified bovine SERPINA3s. SERPINA 3-1 (uniprotkb:Q9TTE1) binds tighly to human CASP3 (uniprotkb:P42574) and CASP8 (uniprotkb:Q14790) with kass of 4.2 × 105 and 1.4 × 106 M−1 s−1, respectively. A wholly similar inhibition of human CASP3 and CASP8 by SERPINA3-3 (uniprotkb:Q3ZEJ6) was also observed with kass of 1.5 × 105 and 2.7 × 106 M−1 s−1, respectively and form SDS-stable complexes with both caspases. By site-directed mutagenesis of bovSERPINA3-3, we identified Asp371 as the potential P1 residue for caspases. The ability of other members of this family to inhibit trypsin and caspases was analysed and discussed.

Structured summary

MINT-7234656: CASP8 (uniprotkb:Q14790) and SERPINA3-1 (uniprotkb:Q9TTE1) bind (MI:0407) by biochemical (MI:0401)MINT-7234634: SERPINA3-3 (uniprotkb:Q3ZEJ6) and CASP3 (uniprotkb:P42574) bind (MI:0407) by biochemical (MI:0401)MINT-7234663: CASP8 (uniprotkb:Q14790) and SERPINA3-3 (uniprotkb:Q3ZEJ6) bind (MI:0407) by biochemical (MI:0401)MINT-7234625: SERPINA3-1 (uniprotkb:Q9TTE1) and CASP3 (uniprotkb:P42574) bind (MI:0407) by biochemical (MI:0401)  相似文献   

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