The graduate student Farah Hamed Rashid optained her Ph.D. from the Department of Applied Sciences at the University of Technology for her thesis entitled " Preparation and characterization of polymer composite for biofilteration application " in the field of materials technologies, which was held in the hall of the deceased Dr. Abdul Muttalib Ibrahim Al-Sheikh.

The discussion committee consisted of professors Balqees Mohammed Ziauddin  as a president and Prof. Dr. Salma Mohamed Hassan, Prof. Dr. Enas Mohy Hady, Prof. Abdel Hamid Rahim El Sarraf, Prof. Amal Ali Hussein as members, Prof. Nahida Gomaa Hamid Supervisor, Prof. Ali Abd El Rahman Taha Co-supervisor.

 The studying included In the present study,preparation andcharacterizationof polymer system tobe usedas biofilterhave been investigated.

Chitosan / root or shoot powders and ash ofwater hyacinth (Eichhorniacrassipes) alone and in composite forms at differentratios (2.9 - 30.3%) were prepared ,separately.Two type of waste water were used in the present study.The first one was collected and prepared at different concentrations (250-1000 ppm) as a standard.Higher removal ratio was observed when pb(ll) ,  Cu(ll) and Cd (ll) were treated with plant shoot or root powders .On the other hand, SEM images displayed a regular shape and high porosity of prepared samples, while FTIR spectra of composite materials showed the characteristic of raw materials bands, which give strong evidence of composite formation . Moreover, the heavy metal removal increased whenever plant root or shoot ratio increased, while the removal by root powder of plant was more than the shoot. On the other hand , the results proved that the highest heavy metal removal, by chitosan beads , were12 , 15 and 18 % forCd , Cu and Pb, respectively.Furthermore, the resultsdisplayed that the compositeof chitosan and plant parts exhibited excellent ability to remove heavy metals. Lower amount  of plant root with 30 mg chitosan appeared 100% removal of Cu(ll) , 86% of  Pb and 60% of Cd(ll) , while the plant shoot ash hyacinth plant with chitosan composite removed 98.2% of  Pb , 98% of Cu and 60% of Cd , when 250 ppm of metals was used.

The effect of pHand temperatureon free and immobilized laccaseto decolorize phenol red dyewere studied .The optimum pH and  temperature of immobilized laccase was 4.6 and30^◦C , respectively .Synthetic and natural mediators , HBT and Vanillin , were used to enhance phenol red decolorization and in LMS . The decolorization percentage of phenol red by chitosan composite with plant root was 100% within 210 minutes in the presence HBT mediator. On the other hand , higher conversion of anthracene was observed by chitosan/ plant parts powder  in the presences of HBT at  30 ºC within 24 hrs.

The ability of composite recycling , as a sorbent material , wasinvolved.It was seenthat the removal efficiency ofheavy metals was decreased within 6cycles and the adsorption ability reduced to 20% , while the activity reaches to 60%  after 9 cycleswhen immobilized laccase in chitosan beads was used.

In conclusion ,the composite acts asabiofliter through removal heavy metals as adsorbent ;decolorization of phenol red dye and conversation ofanthracene in waste water treatment.The recycle studied indicated that  the composite  could  be discount the cost of adsorbent material  for the removal of heavy metals from aqueous solutions by reusing it many times.