Carbon nanoparticle facilitated functional pyramid solar distillation unit for wastewater treatment

Abstract

This paper proposes an efficient treatment of reverse osmosis reject (RO reject) and kitchen wastewater (KWW) in a locally developed single-stage functional pyramid solar distillation unit (FPSDU). The working mechanism of the designed and developed solar distillation unit, its specifications, treated water characteristics, novelty over conventional units, and economic analysis have been discussed in detail. The concept of coating glass beads is attempted for its functional application in solar still for generating photothermal heat. Carbon nanomaterials (CNP) coated glass beads were used as a heat storage medium. FPSDU produced approximately 6003 mL/m2day of treated water for KWW and 5868 mL/m2day for RO reject wastewater vis-a-vis output of 3000 mL/m2day for conventional solar distillation unit with an input of 7000 mL/m2day of wastewater in each case. This demonstrates that the FPSDU shows an improved performance than conventional distillation units, recovering about 85% of the treated water from KWW and RO reject wastewater as compared to 43% for conventional distillation units. The basin surface showed no signs of corrosion and the coating remained stable even after multiple cycles. The treated water met the criteria as per Indian standards, free with microbial contamination and can be used for different non-potable uses. Findings of the current research supports the improved effectiveness of FPSDU for RO reject and KWW treatment with immobilized carbon nanoparticles.