Getting so much time delay in WCF webservice response

Getting so much time delay in WCF webservice response

I have a WCF webservice which sends(returns) DataTable to the client. Now
i have 47,000 records in datatable. At the first call its taking too much
time to get the data.
i had set Generate serialization assembly to 'on' and tried
useDefaultWebProxy="false" in config file but problem couldn't solve.
here is my app.config
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<configSections>
</configSections>
<system.serviceModel>
<bindings>
<wsHttpBinding>
<binding name="WSHttpBinding_I123Services"
closeTimeout="00:30:00"
openTimeout="00:30:00" receiveTimeout="00:30:00"
sendTimeout="00:30:00"
bypassProxyOnLocal="false" transactionFlow="false"
hostNameComparisonMode="StrongWildcard"
maxBufferPoolSize="524288" maxReceivedMessageSize="500000000"
messageEncoding="Text" textEncoding="utf-8"
useDefaultWebProxy="false"
allowCookies="false">
<readerQuotas maxDepth="32" maxStringContentLength="8192"
maxArrayLength="2000000"
maxBytesPerRead="2000000"
maxNameTableCharCount="16384" />
<reliableSession ordered="true" inactivityTimeout="00:30:00"
enabled="false" />
<security mode="Transport">
<transport clientCredentialType="None"
proxyCredentialType="None"
realm="" />
<message clientCredentialType="Windows"
negotiateServiceCredential="true" />
</security>
</binding>
</wsHttpBinding>
</bindings>
<client>
<endpoint address="https://123.com/123services.svc"
binding="wsHttpBinding"
bindingConfiguration="WSHttpBinding_I123Services"
contract="123Services.I123Services"
name="WSHttpBinding_I123Services" />
</client>
</system.serviceModel>
</configuration>
can anyone help me to find me a solution for this. thank you.