Writing style in academic English [comments from my supervisor]


  You still have a tendency to use phrases such as "All in all", and "To
  this end". Not a serious problem of course, but be aware that the
  editors/reviewers for some scientific journals will not accept such
  wording - they will see it as a waste of words (the phrases have
  little real meaning, after all) and will encourage a more concise form
  of writing. You also continue to split infinitives (e.g. "To
  effectively curtail"), again not a serious problem, but not "good"
  formal English if that is what you are aiming for.


Above are some comments from my supervisor on my writing styles. So how should I improve from here, for instance, if not saying 'all in all', 'to this end', what connecting words should I use. And, if not starting a sentence with infinitives, how should I restructure my sentences. 

[the referred sentence that has a bad style]


  To effectively curtail pollution from all sources requires attention
  paid to the long-overlooked industrial pollution. To this end, this
  PhD research emphasises the need to ...
Your supervisor's first objection is against empty "connecting words", as you call them. Since they are empty, you may as well drop them:


  To effectively curtail pollution from all sources requires attention paid to the long-overlooked industrial pollution. [To this end T]his PhD research emphasises the need to...


Your argument, rather than some connecting words, should build the connection:


  To effectively curtail pollution from all sources requires attention paid to the long-overlooked industrial pollution. This PhD research emphasises the important role of industrial pollution in most immissions today [or whatever your argument is]. 


The second objection is not against starting sentences with an infinitive, but against splitting infinitives. I don't know whether split infinitives are really bad style or just a matter of taste. Since some of your readers believe the former, I would err on the side of caution. From Wikipedia:


  The opening sequence of the Star Trek television series contains a well-known example, where William Shatner says "to boldly go where no man has gone before"; the adverb boldly is said to split the infinitive to go. 
  [...]
  The construction is to some extent still the subject of disagreement, but modern English usage guides have dropped the objection to it.


Here are my additional two cents: Avoid the passive voice. Who does the "requiring" in your first sentence? Who must pay attention?


  To curtail pollution from all sources, researchers and policy makers must pay more attention to the long-overlooked industrial pollution. This PhD research emphasises the important role of industrial pollution in most immissions today.