Rahul KumarPhogat, Deepak2024-01-092024-01-092023-07https://krishikosh.egranth.ac.in/handle/1/5810206065Phosphorus (P) is an essential nutrient for all living beings and a limiting nutrient for plants. Chemical fertilizers have high aqueous solubility, low thermal stability and low nutrient holding capacity. Most of the phosphate fertilizers are significantly lost to the environment through different mechanisms like leaching, hydrolysis, degradation and photolysis leading to low nutrient use efficiency (NUE) for plants. The high level of phosphate (as low as 0.02 ppm) increases the photosynthetic aquatic microorganisms in the water and causes eutrophication which further leads to generation of algal bloomsse over the next 50 years with increasing population. Therefore, smart technologies must be developed to reclaim phosphorus from phosphate-rich water to avoid surface water eutrophication and to reduce scarcity of phosphorus. The recovery of phosphorus from waste water and its utilization as fertilizers in fields is a smart approach that will not only reduce the environment pollution, Various accessible technologies including enhanced biological phosphate removal, membrane filtration, chemical precipitation and adsorption are used to remove phosphate from waste water. The high cost, sludge production and disposal makes chemical and biological treatments less appropriate. Out of these, adsorption has proven the most effective technique for phosphate removal due to its simple design, easy to operate, adsorbent regeneration ability and production of low amount of side products.Even at low concentration of phosphorous (below 0.1 or even 0.01 mg-P L−1) as present in some industrial and domestic waste water, Biochar, can be proved a better option for phosphate removal from waste waters. Biochar is a carbonaceous, porous, low-density material that persists in soil from decades to millennia International Biochar Initiative (IBI)). Thus, use of biochar for P recovery from wastewaters and its utilization as phosphate fertilizer in the soil, is becoming a widespread idea which addresses not only the problem but also ensures its reuse. conversion of sweet lemon peel waste into a value-added product like biochar is a sustainable and green approach for its smart management. Biochar prepared at different temperatures did not exhibit any antimicrobial activity against Providencia species. No inhibition zone was found on Luria Bertani agar plates. PW5 grows well in presence of biochar. Hence, Biochar is not found to be toxic for bacterial growth. The maximum removal (95%) of PO43--P occurred for adsorbent dose 1g/L indicated the quantitative removal of PO43--P from water. Maximum adsorption (35mg/g for 40 ppm P solution) of phosphate occur at pH 2 but in real this much pH is not find generally and also there is not any significant difference in adsorption capacity in pH range (4-6). The adsorption capacity (78.564 mg/g at 25℃) of biochar was found to be remained constant after 90 mgL-1. So, the optimum adsorbate concentration for maximum adsorption is taken as 90 mgL-1. Phosphate (PO43-) release pattern for P-loaded biochar based slow release fertilizer was significantly lower than that of conventional phosphorous fertilizer DAP.EnglishThesis