There is more than one correct way of disposing writings which are considered holy. Based on your example, you are using the word 'Allah', this one word would be considered holy, while the rest of the text can be disposed of in any halal manner. To expand, any word or phrase using 'Allah' (Bismillah, Abdullah, etc.) would need to be treated in such a manner. I would recommend cutting out the word(s) and storing them in a safe place until you can dispose of them properly.
The traditional methods are listed below, in order of preference.
- Burial, preferably in a place where people will not walk over, such as a graveyard.
- In flowing water, so that the ink will wash out, and the paper will break up naturally.
- Burning, must be done completely and only with other holy material. Many say to them scatter the ashes on flowing water.
Nowadays, the following options are also available:
- Shredding, must be done until the text is not recognizable.
- Permanent storage, mainly used for old Qurans.
In many places, the local mosque may take your papers to dispose of them in the same manner they would with old mushafs.