Herein, we proposed an affordable and facile way of treating the hardening of water from local groundwater and seawater sources. This was facilitated by synthesizing zeolitic materials via an effortless and affordable method from readily available disposed of waste materials. Firstly, by converting waste aluminium (scrap wire cables, takeaway foil, cans, and spray aerosol bottles) along with disposed of silica gel into active zeolitic materials with the aid of a conventional domestic microwave. Small amounts of the produced zeolites (NaX and NaA) were utilized in the removal of the hardness of water (10 g.L-1), showing elimination of Ca 2+ and Mg 2+ ions within 30 minutes, removing 90% of the total hardness (> 1000 ppm). The spent zeolite samples can be further used for more than two consequent cycles, then the regeneration can be promoted by using NaCl solution at ambient conditions. The total price for the synthesis of 1 kg of the zeolite produced herein is 14 $/kg. This is 70% lower than the price of commercial zeolites available in the market. Our proposed facile route in zeolite preparation could potentially change the traditional costly softening treatment techniques. It also minimizes the use of extra chemical materials, templates and multistep procedures. The excellent hardness removal capacity in groundwater and seawater using synthesized zeolite samples could open doors for various applications.

The strategic idea in this work was to increase pH values by employing natural alkali sources (i.e., HCO3− and CO32−) from four tested agro-ashes as an alternative to chemicals (i.e., lime or soda ash). The considerable proportion of carbonates and bicarbonates in the investigated ash products had remarkable features, making them viable resources. All ash materials showed a significant ability for Ca ion elimination at high initial Ca ion concentrations. A slight quantity of ash (10 g/L) was sufficient for usage on very hard water contents up to 3000 ppm. Finally, the tested agro-ash was free of cost. Furthermore, unlike other conventional precipitants, such as NaOH, Ca(OH)2, NaHCO3, Na2CO3, and CaO, they are cost effective and ecologically sustainable. There is no need to employ any additional chemicals or modify the agro-ash materials throughout the treatment process. The benefits of the manufactured ash were assessed using a SWOT analysis.