<p>1.&nbsp; How about "As the largest global firm working in these fields, we have developed cutting-edge technologies and provided solutions to major challenges in the areas of<br />water and process technologies, energy, renewable resources, and biogas, among others."</p>
<p>&nbsp;2.&nbsp; Your&nbsp;revision&nbsp;works well. <br /><br />3.&nbsp; Yes,&nbsp;"arisen" is correct, this was a typo for which I apologize.&nbsp; </p>