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To enhance the codigestion of degradation and improve biomethane production potential, sugarcane bagasse and filter mud were pretreated by sodium hydroxide NaOH 1 N at 100°C for 15, 30, and 45 minutes, respectively. Biomethane generation from 1-liter batch reactor was studied at mesophilic temperature (37 ± 1)°C, solid concentrations of 6%, and five levels of mixing proportion with and without pretreatment. The results demonstrate that codigestion of filter mud with bagasse produces more biomethane than fermentation of filter mud as single substrate; even codigested substrate composition presented a better balance of nutrients (C/N ratio of 24.70) when codigestion ratio between filter mud and bagasse was 25 : 75 in comparison to filter mud as single substrate (C/N ratio 9.68). All the pretreatments tested led to solubilization of the organic matter, with a maximum lignin reduction of 86.27% and cumulative yield of biomethane (195.8 mL·gVS−1, digestion of pretreated bagasse as single substrate) obtained after 45 minutes of cooking by NaOH 1 N at 100°C. Under this pretreatment condition, significant increase in cumulative methane yield was observed (126.2 mL·gVS−1) at codigestion ratio of 25 : 75 between filter mud and bagasse by increase of 81.20% from untreated composition.

The present research emphasized the utilization of a novel sequential thermochemical and sonication pretreatment technology to enhance methane production from corn stover. The corn stover was thermochemically pretreated with sodium hydroxide to enhance its lignocellulosic digestibility. Due to thermochemical pretreatment, 65.45% lignin removal and 36.33% hemicellulose solubilization was observed and further five sonication levels were employed (25, 45, 60, 90, and 120 min). All pretreatments were found significant (P < 0.05) to enhance methane production from 14.78% to 73.72% while thermo-NaOH pretreatment with 90 min sonication time was proven as the optimum pretreatment with specific methane production of 320 mL/g volatile solids (VS). Anaerobic digestion process stability was deeply monitored at 3 day intervals via total volitile fatty acids, alcohol production, pH, chemical oxygen demand, and VS removal.

In this study, water sorption isotherm for date powder of Istameran variety was obtained using static gravimetric method. Guggenheim, Anderson and de Boer model was adequately fitted to the whole range of water activities and the model parameters were estimated within a reasonable range. The monolayer moisture contents for Brunauer, Emmett and Teller model and Guggenheim, Anderson and de Boer model were obtained to be 3.97 and 0.147 gwater/gdry solids, respectively. The modeling procedure for predicting Tg was performed using various model systems including water as well as fructose and glucose as the major sugars found in Istameran. Brostow et al.'s model based on WFG with an even ratio of glucose and fructose showed the best prediction. Moreover, for modeling Tg as a function of Aw, Roos model indicated an acceptable fitting. By increasing the water mass fraction from 0.006 to 0.214, Tg of the samples decreased linearly from 21.5 to −65.7C. The use of the multicomponent mixtures and modeling procedure held a rational approach for theoretical determination of Tg of date powder as a function of water mass fraction as well as Aw. Practical Applications The present study would be economically advantageous as it explains water sorption isotherm and various model systems for predicting and modeling glass transition temperature for Istameran date powder as one of the most important commercial date varieties. The powder is produced from secondary quality dates. The results are applicable by date powder producing industries during processing and storage for controlling the stickiness.

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To study the optimum process conditions for pretreatments and anaerobic codigestion of oil refinery wastewater (ORWW) with chicken manure, L9 (34) Taguchi's orthogonal array was applied. The biogas production (BGP), biomethane content (BMP), and chemical oxygen demand solubilization (CODS) in stabilization rate were evaluated as the process outputs. The optimum conditions were obtained by using Design Expert software (Version 7.0.0). The results indicated that the optimum conditions could be achieved with 44% ORWW, 36°C temperature, 30 min sonication, and 6% TS in the digester. The optimum BGP, BMP, and CODS removal rates by using the optimum conditions were 294.76 mL/gVS, 151.95 mL/gVS, and 70.22%, respectively, as concluded by the experimental results. In addition, the artificial neural network (ANN) technique was implemented to develop an ANN model for predicting BGP yield and BMP content. The Levenberg-Marquardt algorithm was utilized to train ANN, and the architecture of 9-19-2 for the ANN model was obtained.

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