I'm doing a research project on Maltese (which, in brief, is a descendant of Arabic - very close to the Tunisian Dialect of Arabic) - and I thought you mind find this interesting.
Here's an excerpt from Martine Vanhove's article "La Langue Maltaise, un carrefour linguistique" which you might find interesting:
"...Des variantes vocaliques se sont phonologisées par transfert de distinctivité, et désormais de nombreux mots s'opposent par le timbre de la voyelle et non plus par la qualité de la consonne: /sayf/ (ar. s̟ayf) "été".vs. /seyf/ (ar. sayf ) "sabre", /barad/ (ar. tun. bar̟ad) "limer" vs. /bired/ (ar. tun. bred) "devenir froid". La présence de la voyelle d'arrière /a/ permet ainsi de restituer une ancienne consonne emphatique: /batal/ "devenir vacant" < ar. bat̟al/, /dalam/ "s'assombrir" < ar. d̟alam..."
So as you can see, Maltese has not maintained "emphatic" consonants in its writing system (its written using the Latin alphabet with some additions) BUT the 'essence' of those Arabic emphatic survives in Maltese in the vowels rather than the consonants. [For those who don't know French]: The excerpt is essentially talking about how the 'distinction' between emphatics and non-emphatics is preserved in the vowel patterns rather than the consonants themselves -- so for example, "صيف" (summer) in Maltese is written "sayf" /səjf/ while "سيف" (sword) is written "seyf" /sɛjf/ and so on.
So even though, as in this example, the phonetic value of the grapheme "s" does not change - the Arabic "emphatic" has trickled down in the fronting of the vowel etc.