The water is a life’s key for planet especially in Africa that is the most request for agriculture, however, the pollutants exist in water which makes water unhealthy for human beings 1.
The discharging of color solution to Nile water is the one of contamination which come from dyes used in textile, leather, rubber, and paper industries. Not only human health, but also aquatic life will be affected by structures of dyes 2. By talking about effecting of dyes, it has a direct toxic effect including tumors, skin irritation, allergies, heart defects and mutations 3, 4. According to dye’s structures, world produced 10,000 types of dyes and approximately 7×105 tons produced annually 5. Almost 200,000 tons of dyes was streaming in dying process 6. Dyes can be classified to cationic and anionic dyes, but toxicity of cationic more than anionic 7. Among cationic dyes, brilliant green (Br.
G) and toluidine blue (To.B). Br.G is yellowish-green crystal which used as veterinary medicine, dermatological agent and for prevent mould for poultry 8. Releasing this dye in water can cause for humans, nausea, vomiting, diarrhea, causing coughing and shortness of breath 9. To.B is thiazine cationic dye model, enters in textile and medicine industry 10.
Azo dyes type as trypan blue (Tr.B), it is used in coloring silk, cotton, nylon, wax and plastics. Wastewater contaminated by Tr.B can cause bladder cancer and reticulum-cell sarcomas of the liver 11.
Seeking for methods to remove these dyes from water is the environmental demand, methods can be physical, chemical, biological, radiation and electrochemical 12. The adsorption method is the favorite one for treatment of wastewater as it is efficient process and doesn’t cost a lot. As well as adsorption has ability to regeneration and recovery for adsorbents several times 13. Adsorption is like adhesion of solution the surface of solid molecules. Adsorption have two section, adsorbate and adsorbent.
Adsorbent must have high porous structure with attraction forces to concentrate solute to the solid surface 14. At that case, we choose polyurethane foam (PUF) as adsorbent and Br.G, To.
B and Tr.B dye solutions used as adsorbate.The reason for choosing PUF due to presence of polar and nonpolar in its structure make it good for extraction different materials 15, besides it is available with low cost and ability to reuse after dye desorption 15. Another reason that polymeric foam as PUF has high porosity, weight is light, separation capacity is large and easy for dyes 16. Cell open porous PUF was used as ability for removal of pollutants more than closed cell one as surface area was larger 17. Schiff’s base vanillin thiourea polyurethane foam (SVT-PUF) was synthesized by using thiourea (NH2CSNH2) and vanillin (C8H8O3). Metal oxides nanoparticles have a great concern in last few years because mechanical, structural, thermal, electronic, magnetic, and optical properties are miscellaneous.
The meaning metal oxides is Zinc oxide (ZnONPs) which recognized as physical , chemical and mechanical stability is good and thermal stable, moreover it is available with low cost and not harmful for environment 18. High porous surface of SVT-PUF make it perfect for immobilizing different materials in its matrices as ZnONPs to form SVTPUP@ZnONPs nanocomposite which has an excellent sorption properties.The aim of this work to find sorbent, easy to find, environmentally friend, high surface area and finally can remove different types of dyes either cationic dye (Br.G, To.
B) or azo dye (Tr.B). All of these features available in SVTPUP@ZnONPs. SVTPUP@ZnONPs was got by refluxing it with ZnONPs in ethanol. The final adsorbent was characterized and batch technique was used under different condition, time, concentration, pH and temperature to find optimum for scavenging the meaning dyes.