The phrase "although arduous" is correct and usable in written English.
It can be used to introduce a contrast, typically in a sentence where you acknowledge that something is difficult but may still have positive aspects or outcomes.
Example: "The journey was long and although arduous, it was ultimately rewarding."
Alternatives: "despite being challenging" or "even though it was tough."
Although these arduous climbs are two of the main reasons cyclists come to Mallorca, there are many other ways with gentler gradients beyond the Serra de Tramuntana.
A little more defensive cover could yet be signed but, although an arduous series of early fixtures could sow fresh doubts around the club, Leicester look better prepared for the start of the campaign than most of their rivals, requiring less of a makeover than United, Chelsea, Liverpool and Southampton, all of whom they face, along with Arsenal, in the opening few weeks.
Therefore, although comparatively arduous analytically, narratives are vital in explaining the findings from the quantitative measures.
Although this sounds arduous, many people find, as I do, that weirdly it's easier to write every day than just a few times a week.
Performing a strict assessment and comparison of several conditions appeared arduous: although the subjects of the recommendations were similar, the guidelines did not refer to strictly comparable conditions.
It was arduous work, although Clissett proved so proficient that he once claimed to have made a chair every working day.
Although the pictures are arduous to make, Mr. Bornfriend and others say the technique has rewards that cannot be matched by any iPhone filter or modern camera.
Mr. Steele says that although apartment-hunting remains arduous, the Web makes it easier to understand what you are getting yourself into.
Although it will be arduous to remove them, she is determined: "I've ordered the pink tiles and told my husband we're tearing out the old tile as soon as the Christmas tree comes down".
Although it may be arduous selecting the right tie to wear or which method to tie your tie, be sure to stay on top of your game.
