Three semicontinuous continuous stirred-tank reactors (CSTR) operating at mesophilic conditions (35°C) were used to investigate the effect of hydraulic retention time (HRT) on anaerobic digestion of wheat straw. The results showed that the average biogas production with HRT of 20, 40, and 60 days was 46.8, 79.9, and 89.1 mL/g total solid as well as 55.2, 94.3, and 105.2 mL/g volatile solids, respectively. The methane content with HRT of 20 days, from 14.2% to 28.5%, was the lowest among the three reactors. The pH values with HRT of 40 and 60 days were in the acceptable range compared to that with HRT of 20 days. The propionate was dominant in the reactor with HRT of 20 days, inhibiting the activities of methanogens and causing the lower methane content in biogas. The degradation of cellulose, hemicellulose, and crystalline cellulose based on XRD was also strongly influenced by HRTs.

The reduced natural waters and the large amount of wastewater produced by textile industry necessitate an effective water reuse treatment. In this study, a combined two-stage water reuse treatment was established to enhance the quality and recovery rate of reused water. The primary treatment incorporated a flocculation and sedimentation system, two sand filtration units, an ozonation unit, an ultrafiltration (UF) system, and a reverse osmosis (RO) system. The second treatment included an ozonation unit, a sand filtration unit, and UF and RO systems. The color removal rate increased with the increasing ozone dosage, and the relational expression between the ozone dosage and color removal rate was fitted. Ozonation greatly reduced the color by 92.59 and 97.27 times during the primary and second ozonation stages, respectively. RO had the highest removal rate. The combined processes showed good performance in water reuse treatment. The treated, reused water satisfied the reuse standard and surpassed the drinking water standard rates for chemical oxygen consumption (CODcr), color, NH3-N, hardness, Cl−, SO42−, turbidity, Fe3+, and Cu2+. The operating cost of reuse water treatment was approximately 0.44 USD·m−3.

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The use of acid electrolysed water (AcEW) is a relatively new sanitizing technique for brewery equipment. Experiments showed that a 30% AcEW (a free chlorine concentration of above 17 mg/L) was a sufficient and effective alternative to conventional sanitizers such as peracetic acid (2%). On the basis of the results of industrial-scale clean-in-place tests, an effective AcEW-based clean-in-place procedure, which requires only 10 min of cleaning and does not require final water rinsing after sanitation, was established for the bright beer tank.

This study developed a multiple‐parameter equilibration‐based kilning technology optimization method with a Box–Behnken factorial design and response surface methodology, assessing 10 kinds of indexes from multiple perspectives, including malt stale flavour, malty aroma and sensory evaluation, simultaneously. The results indicated that lipoxygenase (LOX) activity, nonenal potential and sensory score had a tendency to decline, while 4‐hydroxy‐2,5‐dimethyl‐3 (2H)‐furanone, thiobarbituric acid (TBZ) and stale aldehydes increased with the rise in kilning temperature, the extension of kilning time and withering time. The corresponding second‐order mathematical models were established for predicting each parameter. Among them, p‐values of a model equation of LOX activity, nonenal potential, 4‐hydroxy‐2,5‐dimethyl‐3(2H)‐furanone, TBZ, methional and furfural were all <0.05 and R2 values were >0.9, which indicated that these equations had higher significance and that data in excess of 90% could be explained. Subsequently, the numerical optimization of kilning technology was carried out for balancing these positive or negative parameters and the optimum kilning temperature, kilning time and withering time were found to be 86.35 °C, 3.19 h and 14.00 h, respectively. Compared with the values of the original response, the values of the 10 parameters were optimized from 2.2 to 65.2%. This method offers an ability to monitor malt characteristics to obtain higher quality malt. Further, the method will help maltsters and brewers to comprehensively understand malt with different cultivar genetics and growing environments. Copyright © 2016 The Institute of Brewing & Distilling

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