Mixed matrix membrane application for olive oil wastewater treatment:Process optimization based on Taguchi design method Alireza Zirehpour,Ahmad Rahimpour,Mohsen Jahanshahi*,Majid Peyravi
Membrane Research Group,Nanotechnology Research Institute,School of Chemical Engineering,Babol University of Technology,Babol,Iran
a r t i c l e i n f o
Article history:
Received30April2013
Received in revised form
19October2013
Accepted28October2013 Available online27November2013
Keywords:
Olive oil mill wastewater treatment Membrane process
Functionalized carbon nano-tube COD removal
Taguchi method a b s t r a c t
Olive oil mill wastewater(OMW)is a concentrated ef?uent with a high organic load.It has high levels of organic chemical oxygen demand(COD)and phenolic compounds.This study presents a unique process to treat OMW.The process uses ultra?ltration(UF)membranes modi?ed by a functionalized multi wall carbon nano-tube(F-MWCNT).The modi?ed tube has an inner diameter of15e30nm and is added to the OMW treatment process to improve performance of the membrane.Tests were done to evaluate the following operating parameters of the UF system;pressure,pH and temperature;also evaluated pa-rameters of permeate?ux,?ux decline,COD removal and total phenol rejection.
The Taguchi robust design method was applied for an optimization evaluation of the experiments. Variance(ANOVA)analysis was used to determine the most signi?cant parameters affecting permeate ?ux,?ux decline,COD removal and total phenols rejection.Results demonstrated coagulation and pH as the most important factors affecting permeate?ux of the UF.Moreover,pH and F-MWCNT UF had sig-ni?cant positive effects on?ux decline,COD removal and total phenols rejection.Based on the optimum conditions determined by the Taguchi method,evaluations for permeate?ux tests;?ux decline,COD removal and total phenols rejection were about21.2(kg/m2h),12.6%,72.6%and89.5%,respectively. These results were in good agreement with those predicted by the Taguchi method(i.e.;22.8(kg/m2h), 11.9%,75.8and94.7%,respectively).Mechanical performance of the membrane and its application for high organic wastewater treatment were determined as strong.
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1.Introduction
One of the biggest problems in olive oil production is the huge amount of solid and liquid waste produced by the process.This liquid waste,also known as olive oil mill water(OMW),is a serious environmental pollutant in olive oil producing areas.This is because the process has high Chemical Oxygen Demand(COD)and releases phytotoxins.
The high phenolic nature of OMW and its organic contents make it highly resistant to biodegradation.The composition of OMW is variable depending on a wide range of in?uences such as climate, cultivation and the particular milling method used in oil extraction (Akdemir and Ozer,2009;Kiril Mert et al.,2010;Paraskeva et al., 2007).
According to the literature,chemical oxygen demand(COD)of OMW samples can range from35to200g/l,biochemical oxygen demand(BOD)from15to135g/l,suspended solids(SS)from6to 69g/l,total phenols from2to15g/l,while pH ranges from4.5to5.8 (Al-Malah et al.,2000;Bettazzi et al.,2006;Crognale et al.,2006; Fadil et al.,2003;Khou?et al.,2006).This is one of the highest organic loads of all known concentrated ef?uents;it is100e200 times higher than domestic wastewater.
A number of processes have been previously used for OMW treatment including lagooning,physio-chemical treatment(Aktas et al.,2001;Azbar et al.,2004;Ginos et al.2006;Sarika et al., 2005),electro coagulation(Giannis et al.,2007;Inan et al.,2004; Khou?et al.,2007;Tezcan Un et al.,2006),Fenton and Electro Fenton processes(El-Gohary et al.,2009;Khou?et al.,2006;Kiril Mert et al.,2010).Chemical treatment is the most common treat-ment for OMW(Aktas et al.,2001)with membrane separation (Turano et al.,2002).However,reports indicate signi?cant disad-vantages in these treatment methods and showed that no single technology can treat OMW effectively as a stand-alone process (Coskun et al.,2010;Kiril Mert et al.,2010).
Processing methods for OMW treatment using membranes include Micro?ltration(MF),Ultra?ltration(UF),Nano?ltration(NF) and Reverse osmosis(RO).These methods have recently been used
*Corresponding author.Chem.Eng-Nanobiotechnology,Babol University of Technology,P.O.Box:484,Babol,Iran.Tel./fax:t981113220342.
E-mail addresses:mjahan@nit.ac.ir,mmohse@https://www.doczj.com/doc/372898568.html,(M.Jahanshahi).
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Journal of Environmental Management132(2014)113e120
for wastewater treatment due to their applicability and bene?ts of low installation and operational costs(Akdemir and Ozer,2009; Cassano et al.,2011;Coskun et al.,2010;Garcia-Castello et al.,2010).
A common problem for membrane?ltration for OMW treat-ment is that membrane fouling strongly reduces the?ux of per-meates and thus changes a membrane’s selectivity.Fouling also makes the process highly expensive due to repeated plant shut-down for cleaning and washing the membranes(Cassano et al., 2011).Thus,appropriate pretreatment steps are necessary to decrease membrane fouling and increase?ltration ef?ciency. Hence,different chemical and physical pretreatment steps are usually applied ahead of ultra?ltration(Akdemir and Ozer,2009; Cassano et al.,2011;Coskun et al.,2010).
Membrane modi?cation is one of the most effective ways to improve membrane performance in terms of permeate?ux,anti fouling and rejection.Polyethersulfone(PES)is commonly used in preparation of micro?ltration and ultra?ltration membranes because of its good mechanical,chemical and thermal properties.As a result,PES has been con?rmed as the most appropriate membrane material for separation processes including wastewater treatment (Pendergast and Hoek,2011).However,these membranes have hy-drophobic properties that make them highly susceptible to fouling from organic matter.Thus,modi?cation of hydrophobic PES mem-branes is a vital step for overcoming fouling of the membrane.
In other work(Rahimpour et al.,2011),(PES)membranes have been modi?ed through blending PES with a functionalized carbon nano-tube in the presence of polyvinylpirrolidone(PVP)as a pore former in the casting solution.
Membrane?ltration is a complex process;therefore ignoring interactions of factors may result in incorrect conclusions.One way to overcome this problem is to make a set of experiments that account for all possible combinations of factors.Nevertheless, applying this method is time consuming and expensive because the number of experiments needed increases rapidly according to the number of input variables or factors.An alternative is to use a design of experiment(DOE)whereby similar results can be ach-ieved with a smaller number of tests.
Taguchi’s parameter design is a simple and systematic approach to optimize design for performance,quality and cost(Ghani et al., 2004;Park,1996;Phadke et al.,1989).Taguchi’s approach bases experiments on a statistical design(Park,1996).This is important to investigate the effects of multiple factors on performance as well as to study the in?uence of individual factors to determine the most effective factors(Ezzati et al.,2005;Park,1996).
The key membrane factors affecting performance and ef?ciency of a process determine the best selection of operating conditions and pretreatment methods.Operating conditions may vary depending on the speci?c target of the treatment in terms of whether or not a high degree of puri?cation(high degree of COD removal or total phenols recovery)is needed;the importance of high permeate?ux,or lower?ux decline,so selection of pre-treatments,membrane and?ltration is set accordingly.
The aims of this work are:
(i)To determine performance of modi?ed membranes for OMW
treatment in terms of permeate?ux,?ux decline(antifouling properties)and rejection.
(ii)To evaluate the most important operating variables in OMW treatment to improve performance of the membrane and ?nally to determine optimum conditions for achieving higher permeate?ux and higher rejection.
Hence,this investigation was done to evaluate the in?uence of F-MWCNT on membrane performance for OMW treatment.In addi-tion,some important operating variables in different levels are selected to determine their in?uence on OMW treatment.Perfor-mance of the treatment process is evaluated by evaluating permeate ?ux,?ux decline,COD removal and total phenols rejection during OMW treatment.Finally,evaluations are made to determine the key factors necessary to optimize the treatment process.
2.Materials and methods
2.1.Industrial wastewater sample
The raw olive oil mill wastewater(OMW)used in this work was obtained from an olive mill located in Gorgan,Golestan province of Iran.A list of signi?cant characteristics of the raw OMW sample is given in Table1.
These characteristics were determined according to standard methods(Apha,2005).Total phenols were estimated calorimetri-cally using the Folin-Ciocalteu method(Singleton et al.,1999).COD levels were measured using a spectrophotometer of AL250AQUA-LYTICòGermany.
2.2.Pre-treatments
OMW contains a variety of pollutants that cause fouling on membranes so it is necessary to remove them before OMW enters the UF stage.
In order to remove large particles,suspended solids,oil&grease and to reduce initial COD of OMW,several raw feed pre-treatments were tested;a cotton fabric?lter and acid cracking and micro-?ltration(MF).
In the?rst step,a cotton fabric?lter was used to separate large particles.Then acid cracking was applied by decreasing the pH of OMW manually to about2using hydrochloric acid37%(supplied from Merck,Germany).This was done to remove any remaining suspended particles and to hydrolyze oil and fatty acids.The acid cracked OMW was allowed to mature for2h for sedimentation of the suspended solids.Then residuals were separated from the feed tank.
After the acid cracking step,the remaining OMW was pre-?ltered by MF for further removal of suspended solids and COD. The MF process was performed by a20L feed tank,a low-pressure pump,a manometer for measuring pressure,a digital thermometer and a pressure control system followed by a feed?ow meter.A shell and tube heat exchanger was placed into the feed tank and used to maintain the feed temperature at a constant level.A polypropylene (PP)micro?lter membrane with nominal pore size of5microns was also used.The MF system operated at2bar pressure and at the temperature25 C.
In order to evaluate the effect of pH on permeate?ux of the UF membrane,?ux decline,COD removal and total phenols rejection, an NaOH solution was used for pH adjustment by manually increasing the pH of pretreated OMW up to8,as an additional pretreatment.Moreover,in order to investigate coagulation ef?-ciency on the treatment performance indicators,3000mg Là1of
Table1
Characterization of the raw OMW.
Parameter Unit Value
COD g/L57.10?1 Suspended solids g/L14.86?2
Oil&Grease g/L10.32?2 Total phenols g/L 6.65?0.2 Conductivity mS/m12.8?0.1 pH e 4.6?0.1 Total-N g/L0.39?0.1 Total P g/L0.12?0.1
A.Zirehpour et al./Journal of Environmental Management132(2014)113e120 114
FeCl3was used as a coagulant agent in an additional pretreatment. The residual sludge from coagulation was separated from the feed tank after time allowed for sedimentation.
2.3.Membranes and equipment
The mixed matrix ultra?ltration(UF)membranes used in this study were prepared in previous work(Rahimpour et al.,2011). Membranes were modi?ed for this study by adding different con-centrations of the functionalized carbon nano-tube(F-MWCNT)to the membrane matrix.Membranes with different percentages of F-MWCNTs were tested to evaluate performance of the modi?ed membranes for treating OMW.These membranes that had been prepared and presented in previous work were as follows:16%PES, 4%PVP and(0e2wt.%)F-MWCNTs homogenously dissolved in DMAs.The main characteristics of these membranes are listed in Table2,and shown in Fig.1.
SEM image(Fig.1)shows that the modi?ed membrane is an asymmetric membrane with a dense skin layer and large?nger like pores in the sub-layer.The F-MWCNT can be detected in the membrane’s structure.In addition,it can be seen from AFM images (Table2)that the surface roughness of the membrane with2% F-MWCNT was smoother than that of the neat membrane. Furthermore,The zeta potential of the membrane surface was determined using an electro kinetic analyzer as mentioned by the method explained in other studies(Childress and Elimelech,1996; Elimelech et al.,1994).
These experiments were done in concentration mode of?ltration (CMF),where permeates were collected in a separate vessel and concentrates were then circulated back to the feed tank.A high-pressure pump was used to pass the feed solution across the mem-brane surface.Membranes with24cm2area were sandwiched be-tween two parts of a cell.There were two valves,one at the by-pass ?ow and one at end of the cell,to adjust the main?ow rate and desired operating pressure,respectively.Evaluations for permeate ?ux;?ux decline,COD removal and total phenols rejection were determined during120min?ltration.Permeate?ux was monitored every15min and reported as an average.The level of permeate?ux was monitored by measuring the permeate volume collected at a speci?c time described by Darcy’s Equation(Marcel,1991):
J?
1
A m
d V p
d t
(1)
where J is the permeate?ux,A m is the effective membrane area,V p is the total volume of permeate,and t is the?ltration time.
COD removal and total phenol rejection ratio were determined during120min and calculated using the following equation:
Re%T?1à
C p
f ?100
!
(2)
where C p and C f represented concentrations in permeate and feed solutions,respectively.
Flux decline was calculated using the following equation:
FD?
1à
J s
i
?100(3)
where J i and J s represented the initial level of permeate?ux in the ?rst15min and steady permeate?ux in the last15min, respectively.
2.4.Design of the experiments
The Taguchi method was used to design these experiments.The Taguchi method applies fractional factorial test designs called orthogonal arrays that serve to reduce the number of experiments. The selection of a suitable orthogonal array depends on the number of control factors and their levels.This orthogonal array was selected because there was no interaction between factors.The design of experiment(DOE)using the Taguchi method provides a simple,ef?cient and systematic approach to determine optimum conditions(Davidson et al.,2008;du Plessis and de Villiers,2007; Idris et al.,2002).This approach involves numerous steps including design of the experiment,performing the experiments and esti-mating results.
Controllable factors such as pressure,temperature,membrane type,pH and coagulation were selected to estimate effects on the following treatment performance indicators;permeate?ux,?ux decline,COD removal and total phenols rejection.The variables of pressure,temperature and membrane type were selected as oper-ating variables,and pH and coagulation were selected as additional pretreatment steps.Pressure,temperature and membrane type were designed in four levels,and pH and coagulation were designed in two levels.These factors and their levels are presented in Table3.
A Standard L16orthogonal array was employed to design these experiments to include?ve factors(pressure,temperature,mem-brane type,pH and coagulation)and their levels.Each row of the matrix shows one run.The standard L16orthogonal array is pre-sented in Table S1.These(16experiments)are the minimum number of experiments that can be performed effectively to esti-mate the effects of these above-mentioned factors.
The system was kept under experimental conditions.Then, evaluations were made for permeate?ux and rejections.The sys-tem was then operated for2h and?ux was determined at steady state condition.
Levels of signi?cance and importance were determined for the factors by analysis of variance(ANOVA),performed using
Table2
A list of the main characteristics of the membranes.
Membrane (F-MWCNT)Contact
angle a( )
Membrane
zeta potential
at pH2(mV)
Membrane
zeta potential
at pH8(mV)
Roughness a
Sa
(nm)
Sq
(nm)
Sz
(nm)
0%69.1?1.1t3.2à14.2 3.0 3.922.3 0.5%57.6?1.8t7.1à21.4 4.6 5.733.7 1%51.9?2.0t10.2à26.8 4.4 5.838.2 2%48.8?1.5t15.5à34.6 2.5 3.220.3
a From Ref.Rahimpour et al.(2011)
.
Fig.1.SEM image of the membrane with2%F-MWCNT.
A.Zirehpour et al./Journal of Environmental Management132(2014)113e120115
QUALITEK-4(QT4)Version 4.75software.This software is for automatic design and analysis of Taguchi experiments.
In the Taguchi method ‘signal ’and ‘noise ’represent the desir-able value and the undesirable value respectively for output char-acteristics and the signal/noise (S /N )ratio is used to transform quality characteristics (here permeate ?ux,?ux decline,COD removal and total phenols rejection)for optimizing the process (Kim et al.,2007).The equation of the S /N ratio depends on the criteria used for optimization of the quality characteristics.Since high evaluations for permeate ?ux and rejection (COD and total phenols)are preferred,“the larger the better ”criteria was chosen for the S /N ratio.While a low ?ux decline is preferred,so “the smaller the better ”criteria was chosen for the S /N ratio.So in this work,for results of permeate ?ux,COD removal and total phenols rejection the larger the better was used to calculate the corre-sponding S /N ratio,while for ?ux decline the smaller the better was used,equations are as follows:
S =N ?à10log 10
1MSD
eThe larger the better TS =N ?à10log 10MSD eThe smaller the better T
MSD ?
1N
X Y 2
(4)
where MSD is the mean square deviation,Y the response factor (here permeate ?ux,COD removal or total phenols rejection),N is the number of observations (here 2since each trial was repeated).
3.Results and discussions 3.1.Pre-treatment results
Cotton fabric ?ltration,acid cracking and MF were used as ?xed pre-treatment steps.These pre-treatment steps reduced about 63.5%of initial COD,42%of total phenols,85%of suspended solids and 92%of oil &grease.
Pre-treatments of pH adjustment and coagulation were per-formed as optional pre-treatments for some of the trial experi-ments (based on trial experiments suggested by Taguchi method).When the coagulation pre treatment was used before UF ?ltration,evaluations for suspended solids and oil &grease they reduced to about 98%and 99%,respectively,relative to their initial values.
The effect of acid cracking or acidic pH (pH ?2)on OMW can be explained by the increased hydrogen ion (H t)concentration.The negative surface charge of suspended hydrophilic colloid reduced,resulting in neutralization and destabilization.These suspended solids or colloidal materials of OMW were precipitated and thus could easily be separated.In addition,pH reduction is expected to help the process of acidic hydrolysis of oils to fatty acids.It seems that this intensi ?ed the removal process of colloids from OMW.
3.2.Taguchi results
Results of experiments designed by the Taguchi method and the calculated S /N (signal to noise)ratio for each experiment are pre-sented in Tables S2and S3.
Tables S2and S3show that values of the S /N ratio varied among trials and runs.Among the different trials,the trial with biggest value of S /N was variable for different treatment performance in-dicators.The highest S /N value for permeate ?ux was observed at trial 4,while trial 13had the highest S /N value in terms of ?ux decline.In addition,the highest S /N value of COD removal and total phenols rejection was observed at trials 7and 13,respectively.It can be seen that at four of the mentioned trials,pH was at level 2(pH ?8)indicating that an alkaline pH had an overall more positive effect.
Variations of the S /N ratio for different factors at their levels are presented in Fig.2.
It shows that there were different slopes between the lines of various levels (expect for pH and coagulation that were in two levels).This means that each level had a different effect on treat-ment performance indicators.For Example,comparison of S /N ratios of membrane type (Fig.2)show that in the case of permeate ?ux (Fig.2a)the highest S /N value was achieved at the lowest level,wherever the membrane without F-MWCNT was used.On the contrary,in the case of ?ux decline,COD removal and total phenols rejection (Fig.2a e c,respectively)the highest S /N ratios were ach-ieved at the highest levels,where the membranes with 2%F-MWCNT were used.Although permeate ?ux reduced under increasing F-MWCNT concentration in the membrane structure,antifouling properties in terms of ?ux decline and rejections in terms of COD and total phenols improved.So,it may be concluded that modi ?cation of membranes by F-MWCNT had a positive in-?uence on antifouling and rejection capacity of the membranes.F-MWCNT in the membrane matrix leads to a less porous membrane,so membrane permeability was reduced (Rahimpour et al.,2011).Table 2shows that the surface contact angles of the membranes prepared by different concentrations of F-MWCNTs decreased when F-MWCNTs were added to the membrane matrix,suggesting that the hydrophilicity of the membrane surface increased under increasing amounts of F-MWCNT.This is due to the amine a hydrophilic group on the membrane structure formed by adding F-MWCNT in the PES membranes (Rahimpour et al.,2011).In addition,Table 2clearly demonstrates that the membrane sur-face charge in pH acidic and alkaline pH improved by increasing F-MWCNT concentration in the membrane matrix,due to amine charged group in the membranes matrix formed by adding F-MWCNT.
On the other hand,the presence of 2wt.%F-MWCNT in the membrane matrix led to a less porous membrane,so membrane permeability reduced (Rahimpour et al.,2011).Thus lower permeability leads to reduction in permeate ?ux.The higher sur-face charge and hydrophilicity of F-MWCNT-modi ?ed membranes improved antifouling and rejection capacity (COD and total phe-nols)because large amounts of free water was absorbed by highly hydrophilic groups of membrane surface to form a thin water ?lm,which prevented the deposition of OMW components on the membrane surface or pore walls (Huck,1990;Peng et al.,2004).Moreover,the interaction between charged components of OMW and membrane surface charge was classi ?ed as a signi ?cant factor affecting affect ?ux decline.
Table 2shows that charge density of the membrane depends on the pH of the solution in contact with it.The membrane surface charge improved under an increasing concentration of F-MWCNT,at pH 8the highest negative charge was observed for membranes with 2%F-MWCNT.The higher amount of charge on the membrane
Table 3
Factors and levels.Factor
Level 1Level 2Level 3Level 4Membrane type 0%0.5%1%2%Pressure (bar)2468Temperature ( C)20
25
3035pH
2(acidic)8(alkaline)e e Coagulation
Yes
No
e
e
A.Zirehpour et al./Journal of Environmental Management 132(2014)113e 120
116
surface decreases the speci ?c ?ux decline because of enhanced electrostatic repulsion force between charged membranes and charged components in the OMW (Peng et al.,2004).In addition,membranes with smoother surfaces demonstrated lower ?ux decline than those with rougher membranes,due to less fouling.These positive properties of membranes due to F-MWCNT in their structure,led to lower ?ux decline and better antifouling properties.
Comparison of S /N ratios of pressure (Fig.2a)show that there was less increase in permeate ?ux when the pressure changed from 6to 8bar than when it changed from 2to 4bar or 4to 6bar.Thus,it may be concluded that in this case the effect of pressure on permeate ?ux is lower at pressure higher than 6bar.In addition from Fig.2c and d,it is observed that COD removal and total phe-nols rejection decreased slightly under pressure change from 6to 8bar.Thus,it might be determined that in this case the effect of pressure on COD removal and total phenols rejection is negative at 8bar pressure.As a comparison between the S /N ratios of pressure,in the case of ?ux decline the highest S /N value was achieved at the lowest level (P ?2bar)and it decreased under increasing pressure,while the highest S /N value for permeate ?ux was achieved at the highest level (P ?8bar),and the third level (P ?6bar)for COD removal and total phenols rejection.Thus,it can be concluded that there was a negative effect of pressure on rejections of COD and total phenols at pressure higher than 6bar.In addition,increasing pressure had a negative effect on membrane fouling in terms of ?ux decline.This might be due to severe concentration polarization and formation of a denser gel layer on the membrane surface that occurs with increased intensity at higher pressure.Thus,osmotic pressure is increased and effective pressure on the membrane surface is reduced due to the formation of a compact gel layer.Moreover,this can also be related to the theory of critical ?ux introduced by Field and coworkers (Field et al.,1995),the critical ?ux hypothesis is that on start-up there exists a ?ux point below which a decline of ?ux with time does not occur and above it fouling is observed.Hence,it is suitable to operate membrane systems below the point of critical ?ux to avoid severe membrane fouling.
In addition,8bar pressure might be high enough to force OMW components to pass through the membrane.Hence some of these components may pass and cause a reduction in rejection and others may block the membrane pores and increase ?ux
decline.
Fig.2.The variation of S /N ratio of different factors for (a)permeate ?ux of OMW,(b)?ux decline of OMW during trial experiments,(c)COD removal of OMW by UF ?ltration,(d)OMW total phenols rejection by UF ?ltration.
A.Zirehpour et al./Journal of Environmental Management 132(2014)113e 120117
In the case of temperature,shown in Figs.2b e d,the lines that connect levels of temperature are represented by extremely low slopes.This means that changes between levels of temperature do not have a signi?cant effect on?ux decline,COD removal and total phenols rejection.The negligible effect of temperature may be due to the effects of other parameters such as pH and membrane type that were more important,so temperature change between its levels could not affect a considerable change in the results.
COD removal and total phenols rejection improved by adding F-MWCNT to the membrane structure and reached the highest level for2%F-MWCNT membrane due to the electrostatic interac-tion between negatively charged components of the OMW(such as total phenols)and membrane surface charge that improved under increasing F-MWCNT concentration.
Fig.2shows that the highest S/N values for pH and coagulation were achieved when pH was8and coagulation was used,respec-tively.The pH value of wastewater affects the membrane surface charge due to disassociation of the membrane’s functional groups. On the other hand,pH has a major effect on fouling behavior by the OMW components.OMW components may have higher negative charge at pH8.Typically OMW components may lose their charge at acidic pH.At low pH(<4)macromolecules of the OMW such as total phenols have a smaller macromolecular con?guration due to increased hydrophobicity and reduced inter chain electrostatic repulsion.Hence these macromolecules pass more easily through membrane pores(Elimelech et al.,1997;Ghosh and Schnitzer, 1980).They also attach well to membrane surfaces and pore walls.This may account for lower COD removal and total phenols rejection and higher?ux decline of the OMW at acidic pH(pH?2).
The coagulation step helps to agglomerate the OMW contami-nations and facilitates good precipitation.Hence,membrane fouling and pore blocking by these components occurred less.As mentioned above,there was99%suspended solids removal when the coagulation step was applied.Moreover,this elimination by coagulation can also contribute to decreases in COD and total phenols concentration.Less fouling on the membrane surface causes a higher permeate?ux and lower?ux decline is achieved. Thus,it can be concluded that using coagulation and adjusting the pH to8had an overall positive effect.
3.3.ANOVA results
Analysis of variance(ANOVA)was performed in order to determine statistical signi?cance among the factors.ANOVA eval-uates signi?cance of the controlling factors by calculating the F-ratio(variance ratio)and the percentage contribution as shown in Fig.3(Yamini et al.,2008).
The percentage contribution for each factor is de?ned as the portion of a total observed variance in the experiment for each signi?cant factor.The greater the value,the more it contributes to the?nal results.
Fig.3,shows the columns marked as“error/other”that refer to errors caused by uncontrollable factors(noise)that are not included in the experiment and the experimental error.In gen-eral,the value should be below50%otherwise results would not be reliable.Here,the calculated error was about10.41%for permeate?ux experiments,3.54%for?ux decline experiments, 1.09%for COD removal experiments and6.68%for total phenols rejection.It can be seen that these are signi?cantly below the limit.It may mean that nearly all important and effective factors have been considered and that errors in the experiments are not signi?cant.
Fig.3shows that pH had a signi?cant effect on all treatment performance indicators,especially in the case of COD removal and total phenols rejection that had superior effects.On the contrary, effects of temperature were generally negligible.The effect of membrane type was considerable on?ux decline and COD removal. In addition,the effect of coagulation was important for permeate ?ux and?ux decline.
ANOVA may be used to estimate the process performance at optimum conditions.In the Taguchi method optimum conditions are those that may result in the highest S/N.Levels with a high S/N ratio are those that represent the optimum conditions for a considered factor.
The results of optimum conditions of permeate?ux,?ux decline,COD removal and total phenols rejection are listed in Tables4e7,respectively.
Table4shows that the predicted conditions to give maximum permeate?ux are similar to the experimental conditions of trial4, expect for coagulation level.At the optimum conditions predicted by Taguchi the S/N ratio improved to27.2.Thus,predicted permeate ?ux based on the S/N?27.2is approximately22.8kg/m2h.The reason for this improvement is that the levels(experimental con-ditions)in optimum conditions are those with the highest S/N of levels under consideration for a factor.
Table5shows that the S/N value at optimum conditions of?ux decline,predicted by Taguchi,improved to aboutà21.6.Hence,the predicted?ux decline at optimum conditions was about11.9%.
Tables6and7show predicted S/N ratios for COD removal and total phenols rejection at optimum conditions,they were about 37.6and39.5,respectively.Therefore predicted COD removal and total phenols rejection at optimum conditions were about75.8% and94.7%,respectively.
3.4.Validation
Validation experiments need to be done in order to validate the predicted results.If the observed results in the
validation Fig.3.The results of ANOVA for test series,contribution of each factor on the performance indicators.
A.Zirehpour et al./Journal of Environmental Management132(2014)113e120
118
experiments are within the con?dence limit then the predicted results,according to the Taguchi method,are acceptable.
Validation experiments were performed for optimum levels. The observed values of permeate?ux,?ux decline,COD removal and total phenols rejection were about21.2(kg/m2h),12.6%,72.6% and89.5%,respectively.
Values of permeate?ux,?ux decline,COD removal and total phenols rejection at optimum condition were predicted as22.8(kg/ m2h),11.9%,75.8and94.7%,respectively,and they were within the range of the95%con?dence limit.
4.Conclusion
In this study,modi?ed UF membranes were applied for olive mill wastewater treatment.It was observed that permeate?ux was reduced by increasing F-MWCNT concentration in the membrane structure.Antifouling properties of the membrane surface in terms of?ux decline and rejections in terms of COD and total phenols improved signi?cantly.Results of ANOVA determined that the effects of membrane modi?cation in terms of F-MWCNT concen-tration were in a high percentage contribution.Therefore,it is concluded that the effects of membrane modi?cation by F-MWCNT were considerable on the performance of the membrane especially on?ux decline and rejection.The best results for antifouling and rejection were observed when a modi?ed membrane with2% F-MWCNT was used.
It is concluded that in this case,the effect of pressure on permeate?ux was lower at pressure higher than6bar,and its effect on COD removal and total phenols rejection was negative at8bar pressure.In addition,increasing?ux decline at higher pressure means there was a negative effect of pressure on?ux decline.
In this case changes between levels of temperature did not have a signi?cant effect on?ux decline,COD removal and total phenols rejection and since the percentage contribution in ANOVA results was also insigni?cant,it is concluded that the effect of temperature was negligible in the selected range.
These results determined that in this case alkaline pH(pH?8) and coagulation as additional pre-treatments had overall positive effects.Hence,these were determined as effective optional pre-treatments with a signi?cant in?uence,which makes their use strongly justi?able.
The error values according to Taguchi for these experiments were signi?cantly lower than the limit(they were lower than10%), hence it is concluded that nearly all important and effective factors have been considered and that errors in the experiments were not signi?cant.
The optimum conditions determined in this study indicate that based on the target(high degree of puri?cation,high permeate?ux or low?ux decline was target)the selection of pretreatment, membrane and operating conditions of?ltration should be adjusted.
The experiments for validation observed that permeate?ux,?ux decline,COD removal and total phenols rejection(21.2(kg/ m2h),12.6%,72.6%and89.5%,respectively),were within the range of the predicted value’s for con?dence limit,(22.8(kg/m2h),11.9%, 75.8and94.7%,respectively).
Appendix A.Supplementary material
Supplementary material associated with this article can be found,in the online version,at https://www.doczj.com/doc/372898568.html,/10.1016/j.jenvman. 2013.10.028.
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Table5
Optimum conditions for?ux decline.
Factors Level description Level Contribution
Membrane type F-MWCNT2%4 3.524 Pressure2bar1 1.342
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Table6
Optimum conditions for COD removal.
Factors Level description Level Contribution
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Optimum conditions for total phenols rejection.
Factors Level description Level Contribution
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Table4
Optimum conditions for permeate?ux.
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pH82 1.482
Temperature35 C4 1.692
Coagulation Yes1 1.656
Total contribution from all factors:8.288.
Current grand average of performance:18.782.
Expected result at optimum condition:27.16.
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分子植物育种，２００６年，第４卷，第３（Ｓ）期，第８５－９１页 ＭｏｌｅｃｕｌａｒＰｌａｎｔＢｒｅｅｄｉｎｇ，２００６，Ｖｏｌ．４，Ｎｏ．３（Ｓ），８５－９１ 专题报告 Ｒｅｖｉｅｗ 植物基因启动子的克隆方法及其应用 尹辉李丹张毅李秋莉﹡ 辽宁师范大学生命科学学院，大连，１１６０２９ ﹡通讯作者，ｌｉｑｉｕｌｉ＠ｄｌ．ｃｎ 摘要植物基因的表达调控已成为分子生物学研究热点，启动子是基因表达调控的重要顺式元件，启动子的克隆对于研究基因表达调控、构建基因工程载体、表达目的蛋白有着重要的意义。启动子克隆的方法很多，从常用的启动子陷阱技术筛选启动子到ＰＣＲ方法的应用，此后相继问世的一些基于ＰＣＲ的克隆启动子技术，如载体锚定ＰＣＲ、反向ＰＣＲ、接头ＰＣＲ、交错热不对称ＰＣＲ等，为克隆启动子提供了更可靠，更合理的方法。本文着重介绍了几种植物基因启动子的克隆方法，分析了它们的优缺点，并展望了今后的研究前景。 关键词启动子，启动子陷阱技术，反向ＰＣＲ，锚定ＰＣＲ，交错热不对称ＰＣＲ ＣｌｏｎｉｎｇＭｅｔｈｏｄｓｏｆＰｌａｎｔＧｅｎｅＰｒｏｍｏｔｅｒｓａｎｄＴｈｅｉｒＡｐｐｌｉｃａｔｉｏｎｓ ＹｉｎＨｕｉＬｉＤａｎＺｈａｎｇＹｉＬｉＱｉｕｌｉ＊ ＣｏｌｌｅｇｅｏｆＬｉｆｅＳｃｉｅｎｃｅｓ，ＬｉａｏｎｉｎｇＮｏｒｍａｌＵｎｉｖｅｒｓｉｔｙ，Ｄａｌｉａｎ，１１６０２９ ﹡Ｃｏｒｒｅｓｐｏｎｄｉｎｇａｕｔｈｏｒ，ｌｉｑｉｕｌｉ＠ｄｌ．ｃｎ ＡｂｓｔｒａｃｔＴｈｅｅｘｐｒｅｓｓｉｏｎａｎｄｒｅｇｕｌａｔｉｏｎｏｆｐｌａｎｔｇｅｎｅｈａｓｂｅｅｎｔｈｅｈｏｔｓｐｏｔｓｔｕｄｙｉｎｍｏｌｅｃｕｌａｒｂｉｏｌｏｇｙ．Ｐｒｏｍｏｔｅｒｉｓａｎｉｍｐｏｒｔａｎｔｃｉｓ－ａｃｔｉｎｇｅｌｅｍｅｎｔ．Ｃｌｏｎｉｎｇｐｒｏｍｏｔｅｒｉｓｉｍｐｏｒｔａｎｔｔｏｓｔｕｄｙｇｅｎｅｒｅｇｕｌａｔｉｏｎ，ｖｅｃｔｏｒｓｃｏｎｓｔｒｕｃｔｉｏｎａｎｄｔａｒｇｅｔｐｒｏｔｅｉｎｓｅｘｐｒｅｓｓｉｏｎ．Ｆｒｏｍｔｈｅｆｒｅｑｕｅｎｔｌｙｕｓｅｄｗａｙｔｈａｔａｐｐｌｙｉｎｇｐｒｏｍｏｔｅｒｔｒａｐｐｉｎｇｆｏｒｃｈｏｏｓｉｎｇｐｒｏｍｏｔ－ｅｒｔｏｔｈｅｕｓｉｎｇｏｆＰＣＲ，ｔｈｅｒｅｗｅｒｅｌｏｔｓｏｆｗａｙｓｆｏｒｐｒｏｍｏｔｅｒｃｌｏｎｉｎｇ．Ａｆｔｅｒｗａｒｄｓ，ａｓｅｒｉｅｓｏｆｔｅｃｈｎｉｑｕｅｓｂａｓｅｄｏｎＰＣＲｆｏｒｐｒｏｍｏｔｅｒｃｌｏｎｉｎｇｓｕｃｈａｓＡ－ＰＣＲ，Ｉ－ＰＣＲ，ＬＡ－ＰＣＲ，ＴＡＩＬ－ＰＣＲｗｅｒｅｄｅｖｅｌｏｐｅｄｉｎｓｕｃｃｅｓｓｉｏｎ．Ｔｈｅｙｏｆ－ｆｅｒｅｄｍｏｒｅｒｅｌｉａｂｌｅａｎｄｒｅａｓｏｎａｂｌｅｗａｙｓｏｆｃｌｏｎｉｎｇｔｈｅｐｒｏｍｏｔｅｒ．Ｓｏｍｅｗａｙｓｏｆｃｌｏｎｉｎｇｐｌａｎｔｇｅｎｅｐｒｏｍｏｔｅｒｓｗｅｒｅｉｎｔｒｏｄｕｃｅｄ，ｍｅａｎｗｈｉｌｅｔｈｅｌｉｍｉｔａｔｉｏｎｏｆｔｈｅｓｅｗａｙｓｗａｓｉｎｔｒｏｄｕｃｅｄａｎｄｔｈｅｉｒｄｅｖｅｌｏｐｉｎｇｐｒｏｓｐｅｃｔｗａｓａｌｓｏｄｉｓ－ｃｕｓｓｅｄｉｎｔｈｉｓｐａｐｅｒ． ＫｅｙｗｏｒｄｓＰｒｏｍｏｔｅｒ，Ｐｒｏｍｏｔｅｒｔｒａｐｐｉｎｇ，Ｉ－ＰＣＲ，ＡｎｃｈｏｒｅｄＰＣＲ，ＴＡＩＬ－ＰＣＲ 启动子是ＲＮＡ聚合酶能够识别并与之结合、从而起始基因转录的一段ＤＮＡ序列，是基因表达调控的重要元件。启动子对外源基因的表达水平影响很大，是基因工程表达载体的重要元件。植物基因启动子的克隆，对研究植物基因表达调控和构建表达载体至关重要。本文就近几年来克隆植物基因启动子的各种方法做一综述，以期促进对启动子分离技术的应用。 １植物基因启动子克隆的几种方法 １．１利用常规ＰＣＲ技术克隆启动子 对于序列已知的启动子，只需要根据已知的启动子序列设计引物，然后采用ＰＣＲ扩增的方法就可以获得该启动子。该方法比较简便快捷，是近年来使用较为广泛的一种方法。 王利军等（２００４）根据ＧｅｎＢａｎｋ中拟南芥基因组序列中ａｔｓ１Ａ（核酮糖－１，５－二磷酸羧化酶小亚基）基因启动子的序列设计引物，以拟南芥总ＤＮＡ为模板，ＰＣＲ扩增出ａｔｓ１Ａ的基因启动子区片段，将其克隆到ｐＭＤ１８－Ｔ载体上，得到重组质粒并且进行测序，序列分析表明，所克隆的片段为１１１７ｂｐ，与Ｇｅｎ－Ｂａｎｋ中的ａｔｓ１Ａ基因启动子序列比较，发现只在－７７６位缺失１个碱基。 该方法简便、快捷、操作简单，但不能克隆到全新的启动子。
Ｃ语言的常用库函数 函数1。absread()读磁盘绝对扇区函数 原形：int absread(int drive,int num,int sectnum,void *buf) 功能：从drive指定的驱动器磁盘上，sectnum指定的逻辑扇区号开始读取(通过DOS中断0x25读取)num 个(最多64K个)扇区的内容，储存于buf所指的缓冲区中。 参数：drive=0对应A盘,drive=1对应B盘。 返回值：0:成功；-1:失败。 头文件：dos.h 函数2。abswrite()写磁盘绝对扇区函数 原形：int abswrite(int drive,int nsects,int lsect,void *buffer) drive=0(A驱动器)、1(B驱动器)、 nsects=要写的扇区数(最多64K个); lsect=起始逻辑扇区号; buffer=要写入数据的内存起始地址。 功能：将指定内容写入(调用DOS中断0x26)磁盘上的指定扇区，即使写入的地方是磁盘的逻辑结构、文件、FAT表和目录结构所在的扇区，也照常进行。 返回值：0:成功；-1:失败。 头文件：dos.h 函数3。atof()将字符串转换成浮点数的函数 原形：double atof(const char *s) 功能：把s所指向的字符串转换成double类型。 s格式为:符号数字.数字E符号数字 返回值：字符串的转换值。 头文件：math.h、stdlib.h 函数4。atoi()将字符串转换成整型数的函数 原形：int atoi(const char *s) 功能：把s所指向的字符串转换成int类型。 s格式为:符号数字 返回值：字符串的转换值。若出错则返回0。 头文件：stdlib.h 函数5。atol()将字符串转换成长整型数的函数 原形：long atol(const char *s)
HEREDITAS (Beijing) 2010年3月, 32(3): 229―234 ISSN 0253-9772 https://www.doczj.com/doc/372898568.html, 综 述 收稿日期: 2009?09?13; 修回日期: 2009?10?28 基金项目:国家自然科学基金项目 (编号：30871389)和辽宁省优秀人才项目(编号：2009R36)资助 作者简介:朱丽萍(1984?), 女, 硕士, 专业方向：植物分子生物学及基因工程。E-mail: zhuliping0612@https://www.doczj.com/doc/372898568.html, 通讯作者:李秋莉(1969?), 女, 博士, 教授, 研究方向：植物分子生物学及基因工程。E-mail: liqiuli@https://www.doczj.com/doc/372898568.html, DOI: 10.3724/SP.J.1005.2010.00229 植物逆境相关启动子及功能 朱丽萍, 于壮, 邹翠霞, 李秋莉 辽宁师范大学生命科学学院, 大连 116029 摘要: 启动子是调控基因表达的重要顺式元件, 在植物基因表达调控过程中起着重要作用。目前植物抗逆基因 工程中, 人们大多使用组成型表达启动子驱动目的基因的表达。组成型表达启动子虽然能提高转基因植株的抗逆性, 但是其持续过量地表达转化的外源基因会阻碍植物的生长且减少其产量。因此, 只在胁迫条件下才会驱动外源基因表达的诱导型启动子的研究显得尤其重要, 已成为目前研究的热点。文章综述了受非生物逆境和生物逆境胁迫诱导的植物基因启动子的种类和功能, 并展望了植物逆境诱导启动子的研究方向和前景。 关键词: 逆境; 诱导型启动子; 功能分析 Plant stress-inducible promoters and their function ZHU Li-Ping, YU Zhuang, ZOU Cui-Xia, LI Qiu-Li College of Life Sciences , Liaoning Normal University , Dalian 116029, China Abstract: Promoter is an important cis -regulatory element for gene expression and plays an important role in the process of plant gene expression and regulation. Constitutive promoters are being used to drive alien gene expression in most trans-genic engineering. Although constitutive promoters can improve resistance of transgenic plants to abiotic stresses, over- and constitutive-expression of the alien genes have been shown to cause stunted growth and reduction of yield in transgenic plants. Therefore, inducible promoters, which are expressed only when exposed to stresses, are of importance. This paper reviews the types and functions of plant gene promoters induced by bio- and abio-stresses. The prospect of stress-induced promoters was discussed. Keywords: adversity; stress-inducible promoter; function analysis 植物逆境是指对植物施加有害影响的环境因子, 对植物产生重要影响的逆境主要有缺水、低温、盐碱、高温等非生物逆境, 以及病原等生物逆境。无论非生物逆境还是生物逆境都会造成各种农作物产量和质量的下降, 因此, 培育和推广抗逆品种是保证作物稳产高产的有效途径。利用植物自身的抗逆基因, 通过常规育种和分子标记辅助育种方法可以培育抗逆新品种, 然而, 抗性基因在种属间的利用 具有一定的局限性。转基因方法可以克服上述局限, 为作物抗逆育种开辟一条新途径。 植物基因调控主要是在转录水平上进行的, 受多种顺式作用元件和反式作用因子的相互协调。植物基因启动子是重要的顺式作用元件, 它是位于结构基因5′端上游区域调控基因转录的一段DNA 序列, 能活化RNA 聚合酶, 使之与模板DNA 准确地结合, 确保转录精确而有效地起始, 是转录调控的
C语言中常见的功能函数（应掌握的编程） 1、两个变量值的交换 void exchang(float *x,float *y) /*形参为两个变量的地铁（指针）*/ {float z; z=*x; *x=*y; *y=z; } void main() {float a,b; scanf(“%f%f”,&a,&b); exchang(&a,&b); /*因为形参是指针，所以实参必须给变量的地址，不能给变量名*/ printf(“a=%f,b=%f”,a,b); } 2、判断一个整数的奇偶 int jou(int n) /*如果是奇数返回1，否则返回0*/ { if(n%2==0) return 0; return 1; } 3、小写字符转换成大写字符 根据实参传给形参的字母，判断是否是小写字母，如果是小写字母，则转换成大写字母，否则不进行转换，函数返回转换后或原来的字符。 本函数仿照toupper()库函数的功能编写（toupper(c) 是将变量c字母转换成大写字母，如果不是小写字母不转换）。 char toupper1(char ch) {if(ch>=?a?&&ch<=?z?) ch-=32; /*小写字母比对应的大写字母ASCII码值大32*/ return ch; } 4、判断一个字符是否是字母（或数字） 根据实参传给形参的字符，判断是否是字母（或数字），如果是字母（或数字）返回1，否则返回0。此函数是根据库函数isalpha()（或isdigit()）来编写的。 int isalpha1(char ch) /*判断是否是字母*/ {if(ch>=?A?&&ch<=?Z?||ch>=?a?&&ch<=?z?) return 1; else return 0; } int isdigit1(char ch) /*判断是否是数字字符*/ {if(ch>=?0?&&ch<=?9?) return 1; else return 0; } 5、根据学生成绩，返回其等级 char fun(float cj) {char c; switch((int)cj/10) {case 10:
一些比较常用的io函数,总结了一下,一块贴出来了 stdin标准输入流 stdout标准输出流 stderr标准错误流 字符IO函数 1.int getchar() 说明：从stdin读取1个字符 返回值：成功，返回该字符；出错，返回EOF； 2.int fgetc(FILE fp) 说明：功能同getchar，默认从文件fp读取； 返回值：成功，返回该字符；出错，返回EOF； 可以重定向 3.int getc(FILE fp) 说明：功能与fgetc相同，但getc既可以被用作 函数实现，也可以被用作宏实现，并且它的编码效率 可能会更高. 可以重定向 4.int putchar(int ch) 说明：向stdout输出字符ch； 返回值：成功，返回该字符；出错，返回EOF； 5.int fputc(int c,FILE fp) 说明：功能同putchar，默认向fp输出字符ch； 返回值：成功，返回该字符；出错，返回EOF； 6.int putc(int c,FILE fp) 说明：功能与fputc相同，但putc与getc一样既可能被用作 函数实现，也可能被用作宏实现，并且它的编码效率可能会更高；可以重定向 字符串IO函数 1.char gets(char str) 说明：从stdin读取字符串(不包括'n')写入到字符串str中； 返回值：成功，返回str首地址；错误，返回NULL； 2.char fgets(char str,int N,FILE fp) 说明：默认从文件fp中读取N个字符(包括'n')写入到字符串str中，
如果实际输入字符串小于N,fgets自动添加'n'， 返回值：成功，返回字符串首地址；错误或遇到EOF，返回NULL；可以重定向 3.int puts(const char str) 说明：向stdout输出字符串str，然受输出一个'n'， 返回值：成功，返回非负值；错误，EOF； 4.int fputs(const char str,FILE fp) 说明：功能同puts，默认向文件fp写入字符串str； 返回值：成功，返回非负值；错误，EOF； 可以重定向 格式化IO函数 1.int scanf(const char format,...) 说明：根据format从stdin格式化读取N个值，并输入到... 返回值：成功，返回读取的项数；出错，返回EOF 2.int fscanf(FILE fp,const char format,...) 说明：功能同scanf，默认从文件fp读取， 返回值：成功，返回读取的项数；出错或遇到文件尾，返回EOF 可以重定向 3.int sscanf(const char buf,const char format,...) 说明：根据format从buf格式化读取N个值，并输入到... 返回值：成功，返回读取的项数；出错，返回EOF 4.int printf(const char format,...) 说明：根据format格式化数据，并输出到stdout 返回值成功，返回输出字符数；错误，返回负数； 5.int fprintf(FILE fp,const char format,...) 说明：功能同printf，默认向文件fp写入; 可以重定向 6.int sprintf(char buf,const char format,...) 说明：根据format格式化数据，并输出到buf， 返回值：成功，返回输出字符数；错误，返回负数
植物组织特异性启动子的研究进展 摘要：组织特异性启动子也称器官特异性启动子(organ specific promoter)，可调控基因只在某些特定的部位或器官中表达，并往往表现出发育调节的特性。本文介绍了植物组织特异性启动子中的花、果实、种子及叶特异性启动子，并对植物组织特异性启动子研究中问题进行了讨论和展望。 关键词：植物组织特异性启动子，研究进展 启动子(promoter)是RNA聚合酶能够识别并与之结合从而起始基因转录的DNA序列，是重要的顺式作用元件，位于结构基因5’端上游区的DNA序列，能指导全酶与模版的正确结合，活化RNA聚合酶，并使之具有起始特异性转录的形式，决定转录的方向和效率以及所使用的RNA聚合酶类型，是转录调控的中心。目前，植物基因工程中常用的启动子为组成型表达启动子(Constitutive promoter)。组织特异性启动子也称器官特异性启动子(organ specific promoter)，可调控基因只在某些特定的部位或器官中表达，并往往表现出发育调节的特性。外源基因在细胞中表达是基因工程研究的关键，而组织特异性启动子不仅能使目的基因的表达产物在一定器官或组织部位积累，增加区域表达量，同时也可以避免植物营养的不必要浪费。因此，组织特异性启动子一直都是植物基因工程中研究的重点和难点，研究者在植物的分生组织、维管束组织、薄壁组织、花粉、种子和胚乳等几乎各种组织中都发现有组织特异性驱动基因表达的启动子[1]，尤其在根、维管束和韧皮部特异表达启动子研究中取得了很大进展。 1 植物生殖器官表达的组织特异性启动子 1.1 花特异启动子 高等植物发育过程中花器官的形成是一个十分复杂的过程，它包括一系列器官分化及严格控制的细胞及生化变化，同时伴随大量基因的协同表达。植物花特异表达启动子只在植物开花的时期启动基因的表达，它的分离克隆为花卉的品质改良提供了重要的顺式调控元件。 人们克隆了许多花药特异表达的基因，如在花药绒毡层特异表达的TA29[2]和A9[3]以及在花粉壁特异表达的Bp4A[4]基因等，这些基因都是在花药营养细胞中表达，与生殖细胞的分化无关。Mariani等将烟草花药绒毡层特异表达基因启动子TA29分别与核酸酶Bamase和RnaseTl基因融合后转化植物，这两种核酸酶基因在花药中特异表达，破坏绒毡层，获得雄性不育烟草和油菜[5,6]，开创了基因工程创造雄性不育系的先河，至今已在烟草[7]、油菜[8]等植物上获得成功。还有在花药中特异表达的基因，如拟南芥和油菜的APG 基因等。在花粉中特异表达的基因如：玉米的Zm13 (蛋白酶抑制剂)、CDPK （钙依赖型蛋白激酶）、番茄的LAT52、LAT 59及油菜Bp4 、I3 、E2和F2s等。 近年来人们相继分离和鉴定了许多花特异表达基因的启动子，如矮牵牛和金
1.分类函数,所在函数库为ctype.h int isalpha(int ch) 若ch是字母('A'-'Z','a'-'z')返回非0值,否则返回0 int isalnum(int ch) 若ch是字母('A'-'Z','a'-'z')或数字('0'-'9'),返回非0值,否则返回0 int isascii(int ch) 若ch是字符(ASCII码中的0-127)返回非0值,否则返回0 int iscntrl(int ch) 若ch是作废字符(0x7F)或普通控制字符(0x00-0x1F) 返回非0值,否则返回0 int isdigit(int ch) 若ch是数字('0'-'9')返回非0值,否则返回0 int isgraph(int ch) 若ch是可打印字符(不含空格)(0x21-0x7E)返回非0值,否则返回0 int islower(int ch) 若ch是小写字母('a'-'z')返回非0值,否则返回0 int isprint(int ch) 若ch是可打印字符(含空格)(0x20-0x7E)返回非0值,否则返回0 int ispunct(int ch) 若ch是标点字符(0x00-0x1F)返回非0值,否则返回0 int isspace(int ch) 若ch是空格(' '),水平制表符('\t'),回车符('\r'), 走纸换行('\f'),垂直制表符('\v'),换行符('\n') 返回非0值,否则返回0 int isupper(int ch) 若ch是大写字母('A'-'Z')返回非0值,否则返回0 int isxdigit(int ch) 若ch是16进制数('0'-'9','A'-'F','a'-'f')返回非0值, 否则返回0 int tolower(int ch) 若ch是大写字母('A'-'Z')返回相应的小写字母('a'-'z') int toupper(int ch) 若ch是小写字母('a'-'z')返回相应的大写字母('A'-'Z') 2.数学函数,所在函数库为math.h、stdlib.h、string.h、float.h int abs(int i) 返回整型参数i的绝对值 double cabs(struct complex znum) 返回复数znum的绝对值 double fabs(double x) 返回双精度参数x的绝对值 long labs(long n) 返回长整型参数n的绝对值 double exp(double x) 返回指数函数ex的值 double frexp(double value,int *eptr) 返回value=x*2n中x的值,n存贮在eptr中double ldexp(double value,int exp); 返回value*2exp的值 double log(double x) 返回logex的值 double log10(double x) 返回log10x的值 double pow(double x,double y) 返回xy的值 double pow10(int p) 返回10p的值 double sqrt(double x) 返回+√x的值 double acos(double x) 返回x的反余弦cos-1(x)值,x为弧度 double asin(double x) 返回x的反正弦sin-1(x)值,x为弧度 double atan(double x) 返回x的反正切tan-1(x)值,x为弧度 double atan2(double y,double x) 返回y/x的反正切tan-1(x)值,y的x为弧度double cos(double x) 返回x的余弦cos(x)值,x为弧度 double sin(double x) 返回x的正弦sin(x)值,x为弧度 double tan(double x) 返回x的正切tan(x)值,x为弧度 double cosh(double x) 返回x的双曲余弦cosh(x)值,x为弧度 double sinh(double x) 返回x的双曲正弦sinh(x)值,x为弧度
植物基因工程中的常用启动子 _3231 植物基因工程中的常用启动子 植物基因工程中常用的启动子按其作用方式及功能可分为三类：组成型启动子(constitutive promoter )、诱导型启动子(inducible promoter) 和组织特异性启动子(tissue – specific promoter)。这种分类大体上反映了它们各自的特点, 但在某些情况下，一种类型的启动子往 往兼有其它类型启动子的特性。 1 组成型启动子 组成型启动子在所有组织中都启动基因表达，具有持续性，不表现时空特异性；RNA和蛋白质表达量也是相对恒定的。它包括异源和内源组成型启动子两类。植物基因工程中应用的异 源组成型启动子主要有CaMV35S启动子（来源于烟草花叶病毒基因），能在大部分植物中对异 源基因进行启动表达，完整的CaMV35S启动子是植物基因工程中应用最为广泛的组成型启动 子之一，如在马铃薯、拟南芥、烟草、蘑菇、毛白杨等植物中的转基因应用。常用的还有来 自农杆菌的Nos和Ocs启动子。内源启动子主要有水稻肌动蛋白(actin)和玉 米泛素(ubiquitin)基因的启动子，这些启动子可以更有效地驱动外源基因在单子叶植物中的表达。 Naomi等分别从拟南芥的色氨酸合酶β亚基基因和植物光敏色素基因中克隆了相应启动子，
用其代替CaMV 35S启动子，在转基因烟草中也取得了很好的表达效果。用这些启动子代替 CaMV 35S启动子，可以更有效地在单子叶植物中驱动外源基因的转录。组成型启动子已经广泛地应用于双子叶植物、单子叶植物以及真菌等的基因工程中。但是由 于组成型启动子驱动的基因在植物各组织中均有表达，应用中逐渐暴露出一些问题。例如外 源基因在整株植物中表达，产生大量异源蛋白质或代谢产物在植物体内积累，打破了植物原 有的代谢平衡，有些产物对植物并非必需甚至有毒，因而阻碍了植物的正常生长，甚至导致 死亡(karlowaki et al., 2003; Ehasani et al., 2003; Miyao et al., 2003)。另外，重复使用同一种启动子驱动两个或两个以上的外源基因可能引起基因沉默或共抑制现象 (Kumpatla et al., 1998)，因此，人们寻找更为有效的组织、器官特异性启动子代替组成型 启动子，以更好地调控植物基因表达。 2 特异性启动子 特异性启动子可分为两类，一是受诱导表达的启动子，能对外界的物质如病原物、化学物质 或逆境作出反应，启动植物体内相应的生理生化过程。二是组织特异表达的启动子，使基因 在特定的组织中表达。特异性启动子避免了基因过量表达对植物体的伤害，同时可避免外源
C语言常用基本词汇及其他提示语运算符与表达式： 1.constant 常量 2. variable 变量 3. identify 标识符 4. keywords 关键字 5. sign 符号 6. operator 运算符 7. statement语句 8. syntax 语法 9. expression 表达式 10. initialition初始化 11. number format 数据格式 12 declaration 说明 13. type conversion 类型转换 14.define 、definition 定义 条件语句： 1.select 选择 2. expression 表达式 3. logical expression 逻辑表达式 4. Relational expression 关系表达式 5.priority优先
6. operation运算 7.structure 结构 循环语句： 1.circle 循环 2. condition 条件 3. variant 变量 4. process过程 5.priority优先 6. operation运算 数组： 1. array 数组 2. reference 引用 3. element 元素 4. address 地址 5. sort 排序 6. character 字符 7. string 字符串 8. application 应用函数： 1.call 调用 2.return value 返回值 3.function 函数
4. declare 声明 5. `parameter 参数 6.static 静态的 7.extern 外部的 指针： 1. pointer 指针 2. argument 参数 3. array 数组 4. declaration 声明 5. represent 表示 6. manipulate 处理 结构体、共用体、链表： 1 structure 结构 2 member成员 3 tag 标记 4 function 函数 5 enumerate 枚举 6 union 联合（共用体） 7 create 创建 8 insert 插入 9 delete 删除 10 modify 修改
字符函数和字符串函数 头文件：字符串函数头文件：#include
5. Scanf(“%d%c%f”,&a,&b,&c); 输入时1234a123h26↙在输入遇到时空格回车 tab或其他非法输入就会认定输入完毕 Gets (字符数组)：读入字符串函数 Gets（str）从键盘键入a b↙括号里为字符数组str的起始地址，Puts（字符数组）：输出字符串函数 Strcat(字符数组1，字符数组2)：字符串连接函数（2连接在1后面） Strcpy和strncpy:字符串复制函数 Strcpy(字符数组1，字符数组2)：将2复制到1 数组1 要为数组名，字符串2可以为数组名或者字符串 Strncpy(str1,str2,2)：将str2的前两个字符复制到str1，取代str1的前两个字符 Strcmp:字符串比较函数 Strcmp(str1,str2):相等则为0（对字符串自左向右逐个字母进行比较） Strlen(字符数组)：测字符串的实际长度 Strlwr（字符串）将字符串转换为大写 Strupr（字符串）将字符串转换为小写
库函数并不是C语言的一部分，它是由编译系统根据一般用户的需要编制并 提供给用户使用的一组程序。每一种C编译系统都提供了一批库函数，不同的 编译系统所提供的库函数的数目和函数名以及函数功能是不完全相同的。ANSI C标准提出了一批建议提供的标准库函数。它包括了目前多数C编译系统所提供 的库函数，但也有一些是某些C编译系统未曾实现的。考虑到通用性，本附录 列出ANSI C建议的常用库函数。 由于C库函数的种类和数目很多，例如还有屏幕和图形函数、时间日期函数、 与系统有关的函数等，每一类函数又包括各种功能的函数，限于篇幅，本附录不 能全部介绍，只从教学需要的角度列出最基本的。读者在编写C程序时可根据 需要，查阅有关系统的函数使用手册。 1．数学函数 使用数学函数时，应该在源文件中使用预编译命令： #include
头文件ctype.h 函数列表<> 函数类别函数用途详细说明 字符测试是否字母和数字isalnum 是否字母isalpha 是否控制字符iscntrl 是否数字isdigit 是否可显示字符（除空格外）isgraph 是否可显示字符（包括空格）isprint 是否既不是空格，又不是字母和数字的可显示字符ispunct 是否空格isspace 是否大写字母isupper 是否16进制数字（0－9，A-F）字符isxdigit 字符大小写转换函数转换为大写字母toupper 转换为小写字母tolower 地区化 本类别的函数用于处理不同国家的语言差异。 头文件local.h 函数列表 函数类别函数用途详细说明 地区控制地区设置setlocale 数字格式约定查询国家的货币、日期、时间等的格式转换localeconv 数学函数 本分类给出了各种数学计算函数，必须提醒的是ANSI C标准中的数据格式并不符合IEEE754标准，一些C语言编译器却遵循IEEE754(例如frinklin C51) 头文件math.h 函数列表 函数类别函数用途详细说明 错误条件处理定义域错误（函数的输入参数值不在规定的范围内） 值域错误（函数的返回值不在规定的范围内） 三角函数反余弦acos 反正弦asin 反正切atan 反正切2 atan2 余弦cos
正弦sin 正切tan 双曲函数双曲余弦cosh 双曲正弦sinh 双曲正切tanh 指数和对数指数函数exp 指数分解函数frexp 乘积指数函数fdexp 自然对数log 以10为底的对数log10 浮点数分解函数modf 幂函数幂函数pow 平方根函数sqrt 整数截断，绝对值和求余数函数求下限接近整数ceil 绝对值fabs 求上限接近整数floor 求余数fmod 本分类函数用于实现在不同底函数之间直接跳转代码。头文件setjmp.h io.h 函数列表 函数类别函数用途详细说明 保存调用环境setjmp 恢复调用环境longjmp 信号处理 该分类函数用于处理那些在程序执行过程中发生例外的情况。 头文件signal.h 函数列表 函数类别函数用途详细说明 指定信号处理函数signal 发送信号raise 可变参数处理 本类函数用于实现诸如printf,scanf等参数数量可变底函数。 头文件stdarg.h 函数列表
VGA文本16/256K40*25360*4009*16B8000彩色 CGA文本16/1680*25640*2008*8B8000彩色 2/3EGA文本16/6480*25640*3508*14B8000彩色 VGA(3+)文本16/256K80*25720*4009*16B8000彩色 CGA图形4/1640*25320*2008*8B8000彩色 4/5EGA图形4/6440*25320*2008*8B8000彩色 VGA图形4/256K40*25320*2008*8B8000彩色 CGA图形2/1640*25640*2008*8B8000单色 6EGA图形2/6440*25640*2008*8B8000单色 VGA图形2/256K40*25640*2008*8B8000单色 7MDA/EGA文本单色80*25720*3509*14B0000单色 VGA(7+)文本单色80*25720*4009*16B0000单色 D EGA图形16/6440*25320*2008*8A0000彩色 VGA图形16/256K40*25320*2008*8A0000彩色 E EGA图形16/6480*25640*2008*8A0000彩色 VGA图形16/256K80*25640*2008*8A0000彩色 F EGA/VGA图形单色80*25640*3508*14A0000单色 10EGA图形16/6480*25640*3508*14A0000彩色 VGA图形16/256K80*25640*3508*14A0000彩色 11VGA图形2/256K80*30640*4808*16A0000彩色 12VGA图形16/256K80*30640*4808*16A0000彩色 13VGA图形256/256K40*25320*2008*8A000彩色 常规内存函数 申请函数： malloc(),farmalloc(),calloc(),farcalloc(),realloc(),farealloc()函数名:malloc 功能:内存分配函数 用法:void*malloc(unsigned size); 函数名:farmalloc 功能:从远堆中分配存储块 用法:void far*farmalloc(unsigned long size); 函数名:calloc 功能:分配主存储器 用法:void*calloc(size_t nelem,size_t elsize); 函数名:farcalloc 功能:从远堆栈中申请空间
C语言中最常用标准库函数- candyliuxj - CSDN博客 C语言中最常用标准库函数收藏 标准头文件包括： <asset.h> <ctype.h> <errno.h> <float.h> <limits.h> <locale.h> <math.h> <setjmp.h> <signal.h> <stdarg.h> <stddef.h> <stdlib.h> <stdio.h> <string.h> <time.h> 一、标准定义（<stddef.h>） 文件<stddef.h>里包含了标准库的一些常用定义，无论我们包含哪个标准头文件，<stddef.h>都会被自动包含进来。 这个文件里定义： l 类型size_t （sizeof运算符的结果类型，是某个无符号整型）； l 类型ptrdiff_t（两个指针相减运算的结果类型，是某个有符号整型）；
l 类型wchar_t （宽字符类型，是一个整型，其中足以存放本系统所支持的所有本地环境中的 字符集的所有编码值。这里还保证空字符的编码值为0）； l 符号常量NULL （空指针值）； l 宏offsetor （这是一个带参数的宏，第一个参数应是一个结构类型，第二个参数应是结构 成员名。offsetor(s,m)求出成员m在结构类型t的变量里的偏移量）。 注：其中有些定义也出现在其他头文件里（如NULL）。 二、错误信息（<errno.h>） <errno.h>定义了一个int类型的表达式errno，可以看作一个变量，其初始值为0，一些标准库函数执行中出错时将它设为非0值，但任何标准库函数都设置它为0。 <errno.h>里还定义了两个宏EDOM和ERANGE，都是非0的整数值。数学函数执行中遇到参数错误，就会将errno 置为EDOM，如出现值域错误就会将errno置为ERANGE。 三、输入输出函数（<stdio.h>） 文件打开和关闭： FILE *fopen(const char *filename, const char *mode); int fclose(FILE * stream);
常用C语言标准库函数 C语言编译系统提供了众多的预定义库函数和宏。用户在编写程序时，可以直接调用这些库函数和宏。这里选择了初学者常用的一些库函数，简单介绍了各函数的用法和所在的头文件。 1.测试函数 Isalnum 原型：int isalnum（int c） 功能：测试参数c是否为字母或数字：是则返回非零；否则返回零 头文件：ctype.h Isapha 原型：int isapha（int c） 功能：测试参数c是否为字母：是则返回非零；否则返回零 头文件：ctype.h Isascii 原型：int isascii（int c） 功能：测试参数c是否为ASCII码（0x00~0x7F）：是则返回非零；否则返回零 头文件：ctype.h Iscntrl 原型：int iscntrl（int c） 功能：测试参数c是否为控制字符（0x00~0x1F、0x7F）：是则返回非零；否则返回零头文件：ctype.h Isdigit 原型：int isdigit（int c） 功能：测试参数c是否为数字：是则返回非零；否则返回零。 头文件：ctype.h Isgraph 原型：int isgraph（int c） 功能：测试参数c是否为可打印字符（0x21~0x7E）：是则返回非零；否则返回零 头文件：ctype.h Islower 原型：int islower（int c） 功能：测试参数c是否为小写字母：是则返回非零；否则返回零 头文件：ctype.h Isprint 原型：int isprint（int c） 功能：测试参数c是否为可打印字符（含空格符0x20~0x7E）：是则返回非零；否则返回零 头文件：ctype.h Ispunct 原型：int ispunct（int c） 功能：测试参数c是否为标点符号：是则返回非零；否则返回零
（一）输入输出常用函数 1，printf （1）有符号int %[-][+][0][width][.precision][l][h] d -:左对齐 +：正数前加‘+’ 0：右对齐，acwidth