Effect of Untreated Wastewater Reuse in Agriculture and Sustainable Reproach for Micro-pollutan t Removal using Hydrochar

Abstract

The scarcity of freshwater resources has prompted millions of smaller agrarian households in Nigeria depend on marginal water for crop irrigation, fishing and domestic purposes. The marginal water is seen as a viable option to augment the perennial scarcity of freshwater for year-round cultivation. Prolong use of untreated wastewater for agriculture poses threat to public and environmental health. The adoption of water quality guidelines for agriculture is highly desirable for implementation; but, in reality it's hard to achieve in Nigeria, which may be due to factor such as high cost of: procurement, operation and maintenance and sustainability. This gap has prompted the need for exploring other sustainable and effective methods. A thermochemical process called hydrothermal carbonization was employed to produce the needed hydrochar from raw coco-peat, coconut shell, rice hull, lemon peel and chicken eggshell. The hydrochars were characterized using SEM/EDS, FTIR, CHN, BET. The efficiency of each adsorbent was evaluated as follows: Over 90% of Pb²⁺ and Cr⁶⁺ were removed by coco-peat; while 100% of Fe²⁺ and Cu²⁺ were delineated by eggshell; on the other hand, coconut shell performed excellently in decolorizing the simulated wastewater. In conclusion, the use of hydrochar for wastewater treatment hold a promise.