Removal of oxytetracycline from pharmaceutical wastewater using kappa carrageenan hydrogel oleh Muhammad Afzaal, Rab Nawaz, Saddam Hussain, Mahnoor Nadeem, Muhammad Atif Irshad, Ali Irfan, Hafiz Abdul Mannan, Aamal A. Al-Mutairi, Atif Islam, Sami A. Al-Hussain, Mehwish Rubab, Magdi E. A. Zaki