The problems of water are receiving intense attention around the world, lack of fresh water resources and the aggravated pollution level in the ground and surface water encourage the planners and decision makers to capitalize the new wastewater treatment technology. In Palestine, there is a strategy to reuse of treated wastewater in Palestine for irrigation and groundwater recharge is limited due to the strict Palestinian requirements for reuse of treated wastewater. New innovative modification on the traditional tertiary filtration-treatment units using zinc oxide nano photocatalysis is suggested to improve the quality of the treated effluents. In this research, the nano-zinc oxide catalysis was successfully lab synthesized from high purity graded raw chemicals (99.5%) and also from commercial raw materials (purity equal to 95% or greater). No significant difference in the size of the produced catalysis based on the purity of the raw material. Where, the zinc oxide nano photocatalysis was produced in size of 26.5 nm from commercial zinc sulfate heptahydrate and size of 25.7 nm from graded zinc sulfate heptahydrate. In the same manner, nano ZnO catalysis which was produced from commercial micro-sized ZnO have a size of 18.7 which is greater than the nano ZnO catalysis originated from graded raw micro-sized ZnO by just 1.7 nm.
Photocatalytic degradation ability of the produced nano catalysis was tested in batch experiments as powder or after pre-depositing it on the surface of activated carbon or recycled glass. The nano photocatalysis produced from commercial raw chemicals (ZnSO4.7H2O and micro-sized ZnO) shows a high degradation ability for the pollutants in the secondary wastewater with efficacy reaches 85% of total chemical oxygen demand (COD) in the powder batch, and exceeds this value to 97% in the batch of pre-deposited nano catalysis on the surface of the recycled glass.
Carbon and recycled glass were tested as nano photo catalysis carrier. The activated carbon didn’t show the sought-after results where the nano catalysis easily escaped to the solution in the batch experiment moreover the black imperial structure of the AC obstructed sun light and ultraviolet light which activate the photo catalytic reaction causing deficiency in activation of the nethermost photo catalysis. Unlike AC filtration media, the filtration media of crushed glass allows the UV to penetrate its structure and therefore activating the pre-doped nano photo catalysis even in the bottom layers of it.
Finally, the results of this research are the milestone of other researches in order to develop a self-cleaning filtration media.