I'll try to answer your question, sorry if it doesn't satisfy you. This answer is mostly about the view and treatment of freed Africans in the mid to late 19th century

Of course, just like with European nations, the Ottomans enslaved Africans, particularly from East Africa, Nubia, Sudan, and Ethiopia. Because of that, most of Africans living in the Ottoman Empire were either slaves or freed slaves. I'm mostly focusing on free Africans and how they lived in the Ottoman Empire, especially from the tanzimat onwards.

Social Treatment Towards Africans

Ottoman society's view of Africans is characterized by the color-based homogeneity that's applied to Africans, the Us vs Them dichotomy, and the proceeding racial discrimination made against them.

First of all, because of Ottoman society's difficulty in understanding the geographical origins and African languages, Africans of various origins were treated as a single, homogeneous ethnic-racial identity known as "Blacks" (Zenciler) since the "blackness" of their skin were the easiest way to categorize them in a "white" society. Second, in the late Ottoman Empire, local elites and intellectuals associated Africans and African culture with marginal social groups. In their eyes, the marginalized and their culture did not measure up to Ottoman standards. Those people and cultures were uncouth, underdeveloped, primitive, and incomprehensibly bizarre yet exotic which created a dichotomy between the "civilized Ottomans" and "uncivilized Blacks". Lastly, came several stereotyped features associated with the African populace. Most had negative connotations, portraying Africans as ignorant, stupid, lecherous, and adulterous though obviously not all subscribed to these ideas. Nevertheless, discrimination against Africans aren't as intense as in, say, the United States since it was not supported by any state policies. Because of that, Ottoman subjects mingling or having good relations with Africans in individual or wider social level isn't

Because of their often marginalized status, Africans lived in their own neighbourhoods and communities. For example, there are Izmir's Tamaşalık and İkiçeşme, Veroia's Arap Mahallesi, and Agha Balta neighbourhood in Candia. Additionally, in many Ottoman cities there are various African communities centered around lodges led by a kolbası, freed African women who served as heads of these lodges and lead religious processions. The main purpose of these lodges are "for mutual defence and protection, not only against the tyranny of masters and mistresses, but against sickness and other accidents of life". These lodges, with the government's support protected and housed Africans and preserved some form of their way of life. For example, these lodges also functioned as a religious cult whose chief deity was worshipped under such names as Yavroube or Yavru Bey. These lodges would perform African festivals (or a creolized form of it) annually, with even participating Muslim populaces, much to the elite's dismay, as can be seen in these ridicules from the newspaper Hizmet in 1894:

No matter how much the Calf Festival, special only to our city, has been criticized, this custom continues yet again. Despite everything that has been written about this odd and ridiculous tradition, there remains no other way but to smash the people’s ignorance. If we ask them, we shall get this answer: if the calf’s blood is not spilt, then a headless African will come, will cause us trouble, and will bring disease to our city ... We cannot do anything but be sorry for this custom of Africans, which is the result of pure ignorance ... We cannot avoid being amazed and pained at the fact that four or five thousand of our sober-minded white people take part in that Calf Festival, which consists of four or five hundred persons getting together, and with four or five Ottoman liras buying a calf, slaughtering and cooking it

The Ottoman Government and Freed Slaves

In 1857, partly because of British pressure the Porte formally abolished African slave trade (but not slavery or slave trade in general). The edicts (ferman) were dispatched to provincial governors-general, instructing them to prohibit the trade in Africans and that they are responsible to manumit enslaved Africans immediately and give them the necessary lodgings and facilities so that they could settle down in the province. This started the trend of the Porte acting as the "Patron State" to Africans. The Porte recognized its responsibility for the well-being of the men and women freed as a result of the prohibition. Although practice did not always match intentions (as there are many other reasons on why the Porte goes to much lengths on doing this), they realized that unless they actively protected such persons and placed them in gainful jobs, such persons would soon be exploited, abused, and, often, reenslaved. Because of that, the Porte tried various ways to ensure the freed Africans were properly established and integrated in Ottoman society.

Reattaching freed Africans to private elite households and government agencies as free manpower were the most common attempt at doing this. Freed African men were offered place in the various vocational schools and different types of public works, such as mining and salt transportation, all involving physically demanding jobs but with good pay and freedom of movement. Others were just simply drafted into the army, which seems to offer attachment to freed African men more than other government agencies, providing sustenance, shelter, professional training, and a new identity. Many of these men were placed in the various military bands, probably because they were deemed to have musical talents or because a band of black-skinned people performing in state ceremonials had visual impact. Other common placements for freed Africans were in artisan battalions and naval units, where the men were taught technical skills and then deployed to service or combat units, such as artillery, transport, and encampment. Skills acquired in the military could also be used in civilian life after termination of service, potentially putting the men in higher income brackets than were the ones employed in unskilled service jobs. Freed African women were commonly placed in domestic service. Unlike being a domestic slave, they have a legal option to change employers, and they were able to earn income (though meagre) and gradually save up for a future family. Some of the women also received professional training that enabled them to work in other jobs

Later on, In Istanbul, the Ministry of Police, established a hostel (misafirhane) for liberated persons. This was a sort of lodgehouse intended to temporarily host freed slaves until proper employment could be found for them. Though there are problems at first, the establishment of hostels to care for freed Africans became an official Empire-wide policy with a system devised to feed, clothe, and shelter freed Africans paid for by the central government, partly by the local authorities, and partly through financing by local employers who would undertake payment for the free laborers they were gaining through the government emancipation program. In 1884, Sultan Abdülhamid II further ordered that freed Africans be brought from Benghazi to Istanbul and Izmir to avoid a lengthy wait in the province, and then the women were to be placed in domestic service, while the men in military bands and artisan battalions. Additionally, the Sultan launched a settlement program for liberated Africans. The idea was to marry freed men and women to each other, create new village communities for them, and settle them as agricultural workers on state land not unlike the recently adopted Circassian settlement program. However, i don't know if this program were ever adopted throughout the Empire, as it seemed that the program were only ever ran in Aydın.

Of course, things wasn't perfect as there are many problems with this system. Monetary problems were the most frequent, as sometimes there are not enough money to care for the interned slaves. This led to the sometimes horrible conditions in hostels without being fed or cared. The biggest problem however, is that in such a vast empire, with so many diverse and conflicting interests, not all orders from Istanbul were obeyed. Sometimes governor-generals would just simply return the enslaved to their masters or resold them in a different city. All in all, there was a system in place, but it was far from perfect.