First tri done need to improve my running

You didn't say how long you've been running. Is this a recent thing or have you been doing it a while?

For a person who was a non-runner it takes time to improve. Typically much longer than swimming or biking. Those activities support body weight as you move. With running all the weight is supported by the body. The body needs to adapt to the stress. The adaptation process involves muscles, ligaments, tendons, bones, and the blood system to name a few. The body has to work much harder in running so all those things have to be developed - which takes a fair amount of time.

Short answer is you'll need to run more at progressively greater overall volume for a longer period of time. Keep plugging away with a consistent effort and you'll be much improved in 6 months to a year.

It sounds like what you are doing now for running is good.  Your long run should be at least 10 km.  Each week you should try to add more time and/or more repeats and hills to your routine.

There are only two ways to run faster: increase the length of your stride or increase the speed of your stride (all other things staying equal).  I would suggest trying to keep the same stride length and increase the cadence. 

Congrats on your 1st Tri.  Your times are respectable for your 1st and you can improve on them so analyze what went right and what you can do better.

How were your transitions?  What can you do to make them faster and easier?  I learned after my 1st sprint that I wanted tri-shorts to swim in (then bike and run in them as well) plus a tri-top to wear under my wetsuit then wear for the bike and run (they dried really fast) and I bought some no tie laces for my runners that also saved some time.

Your swim time is pretty decent on a "per 100m" basis so just keep practicing.  If you can join a swim group where you swim it will help a lot.

Your bike time was pretty near 25kph.  It has taken me a long time to get there so you've got a pretty good start.

Your run was about 5:49/km = under 1 hour/ 10K  I'd love to be that fast.  Just keep doing what you've been doing.

Have fun.

DOH! Yeah, you're right. I realized this later.

That's still not a horrible time though.

For now you might be better off running more and throwing out the intervals.  Lots of long slow distance runs will build up your aerobic base and have a huge effect on your ability to run faster even for relatively short races.

My N=1 example:  I thought I had a decent base built up and did speed work once a week the entire season last year.  My PR for the Oly distance (10k) on the run was in the 45:30 range which is decently fast, but I was stuck there for most of the year.

  This winter training for my first HIM I dropped all my speedwork and focused on building volume.  I my first Oly this spring a week ago and Crushed my old PR running a 42:12 doing absolutely zero speedwork from October through April.