This study evaluated the coagulant potential of Carica papaya seeds for the treatment of textile effluents, assessing the removal of turbidity, total suspended solids (TSS), and chemical oxygen demand (COD), and comparing with current Peruvian legislation, a 2 5–1 fractional factorial design was implemented to evaluate the effect of pH, coagulant dose (D), rapid mixing time (t RM ), slow mixing time (t SM ), and sedimentation time (t S ) on turbidity removal. Subsequently, a central composite design (CCD) was used to optimize the relevant process variables, identifying an optimum pH 5 and t SM 23.5 min. Under these conditions, removal efficiencies of 70.12 ± 0.70% for turbidity, 67.55 ± 1.08%, for COD and 70.80 ± 1.57% for TSS were achieved. Scanning electron microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy revealed morphological changes and shifts in the surface functional groups of the Carica papaya seed coagulant before and after the coagulation process.
This study evaluated the coagulant potential of Carica papaya seeds for the treatment of textile effluents, assessing the removal of turbidity, total suspended solids (TSS), and chemical oxygen demand (COD), and comparing with current Peruvian legislation, a 25–1 fractional factorial design was implemented to evaluate the effect of pH, coagulant dose (D), rapid mixing time (tRM), slow mixing time (tSM), and sedimentation time (tS) on turbidity removal. Subsequently, a central composite design (CCD) was used to optimize the relevant process variables, identifying an optimum pH 5 and tSM 23.5 min. Under these conditions, removal efficiencies of 70.12 ± 0.70% for turbidity, 67.55 ± 1.08%, for COD and 70.80 ± 1.57% for TSS were achieved. Scanning electron microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy revealed morphological changes and shifts in the surface functional groups of the Carica papaya seed coagulant before and after the coagulation process.
Soil salinity and seasonal water scarcity constrain barley production in coastal agroecosystems, yet their interactive effects on soil conditions, plant physiological responses, and yield remain insufficiently resolved. This study evaluated four irrigation regimes (0, 50, 75, and 100% field capacity) and four nutrient-management strategies (FRG-2018, IPNS + biochar, IPNS + vermicompost, and IPNS + biochar + vermicompost) for their effects on soil properties, physiological responses, and grain yield of barley (Hordeum vulgare L.) across two consecutive growing seasons in coastal Bangladesh. Treatment responses were evaluated using analysis of variance, multivariate analyses, Random Forest-SHAP, structural equation modelling (SEM), and the multi-trait genotype–ideotype distance index (MGIDI). Irrigation strongly affected grain yield (P < 0.001), while amendment treatment (P = 0.032) and its interaction with irrigation (P = 0.002) further modified yield responses. The combination of 75% field capacity and IPNS + biochar produced the highest grain yield, whereas 75% field capacity with IPNS + vermicompost exhibited the most favorable multi-trait performance. Yield variation was associated with soil moisture, reduced electrical conductivity, enhanced K/Na balance, greater chlorophyll accumulation, lower oxidative stress, and yield-related traits. Machine-learning analysis identified spike length, thousand-grain weight, grains spike−1, and plant height as major predictors of grain yield, while physiological variables including moisture, electrical conductivity, chlorophyll, MDA, and POD also contributed to prediction. SEM supported an interconnected soil moisture-ionic balance-physiological status-yield pathway, although these relationships represent statistical associations rather than definitive causal effects. Overall, the findings indicate that combining moderate deficit irrigation with organic amendment can improve barley productivity under the tested coastal saline conditions.
