Anaerobic co-digestion has made a greater impact on the biogas production from mixing different type of waste. In this research, sewage sludge (SS) and cow manure (CM), was used as a primary waste along with kitchen waste (KW), yard waste (YW), floral waste (FW) and dairy wastewater (DWW) as co-substrate for anaerobic digestion. Mixtures with a ratio of 1:2 ratio is fed into a single stage up-flow anaerobic sludge blanket (UASB) reactor. Digestion was carried out in a mesophilic temperature range for 20 days. pH and VFA were measured and ranged from 5 to 7.5 and 3500-500 mg/L, respectively, for all the mixtures throughout the digestion period. Percentage of COD removal efficiency after 20 days was found to be in the range of 76-86%. The maximum biogas production rate was found to be 4500 mL/day. Characterization of the final residue from each of the digesters was carried out by Scanning Electron microscope, Energy dispersive, thermogravimetric, FTIR Spectra, and Atomic microscope. Thermal analysis reveals that spent sludge can be potential waste energy sources.
Incessant utilization of chemical fertilizers leads to the accumulation of minerals in the soil, rendering them unavailable to plants. Unaware of the mineral reserves present in the soil, farming communities employ chemical fertilizers once during each cultivation, a practice that causes elevated levels of insoluble minerals within the soil. The use of biofertilizers on the other hand, reduces the impact of chemical fertilizers through the action of microorganisms in the product, which dissolves minerals and makes them readily available for plant uptake, helping to create a sustainable environment for continuous agricultural production. In the current investigation, a field trial employing Arachis hypogaea L was conducted to evaluate the ability of Pseudomonas aeruginosa to enhance plant growth and development by solubilizing minerals present in the soil (such as zinc and phosphorus). A Randomized Complete Block Design (RCBD) included five different treatments as T1: Un inoculated Control; T2: Seeds treated with a liquid formulation of P. aeruginosa; T3: Seeds treated with a liquid formulation of P. aeruginosa and the soil amended with organic manure (farmyard); T4: Soil amended with organic manure (farmyard) alone; T5: Seeds treated with lignite (solid) based formulation of P. aeruginosa were used for the study. Efficacy was determined based on the plant's morphological characters and mineral contents (Zn and P) of plants and soil. Survival of P. aeruginosa in the field was validated using Antibiotic Intrinsic patterns (AIP). The results indicated that the combination treatment of P. aeruginosa liquid formulation and organic fertilizer (farmyard) (T3) produced the highest biometric parameters and mineral (Zn and P) content of the groundnut plants and the soil. This outcome is likely attributed to the mineral solubilizing capability of P. aeruginosa. Furthermore, the presence of farmyard manure increased the metabolic activity of P. aeruginosa by inducing its heterotrophic activity, leading to higher mineral content in T3 soil compared to other soil treatments. The AIP data confirmed the presence of the applied liquid inoculant by exhibiting a similar intrinsic pattern between the in vitro isolate and the isolate obtained from the fields. In summary, the Zn and P solubilization ability of P. aeruginosa facilitates the conversion of soil-unavailable mineral form into a form accessible to plants. It further proposes the utilization of the liquid formulation of P. aeruginosa as a viable solution to mitigate the challenges linked to solid-based biofertilizers and the reliance on mineral-based chemical fertilizers.