The objective of this study was to evaluate a new alternative for yard waste management by constructing, operating and monitoring a landfill-based two-stage batch digester (anaerobic/aerobic) with the recovery of energy and compost. The system was initially operated under anaerobic conditions for 366 days, after which the yard waste was aerated for an additional 191 days. Off gas generated from the aerobic stage was treated by biofilters. Net energy recovery was 84.3MWh, or 46kWh per million metric tons of wet waste (as received), and the biochemical methane potential of the treated waste decreased by 83% during the two-stage operation. The average removal efficiencies of volatile organic compounds and non-methane organic compounds in the biofilters were 96-99% and 68-99%, respectively. 相似文献
The aim of this research was to preliminary track fecal source male-specific F+RNA coliphages including human and animals in lettuce. At first, two published virus extraction procedures of ultracentrifugation and PEG precipitation were compared using DAL assay for determining the recovery efficiency in lettuce spiked artificially with three concentrations (102, 104, 106 pfu/100 ml) of MS2 coliphage. The results showed that PEG precipitation had the highest recovery in which the recovery efficiency at the spiked level of 106 pfu/100 ml was 16.63 %. Aqueous phase obtained from the final step of PEG method was applied for enumeration of coliphage and viral RNA extraction in naturally contaminated lettuce samples (N = 30) collected from two sources (market and farm). The samples were then analyzed based on (I, II, III, and IV primer sets) using RT-PCR method. Coliphages were detected in 9 (60 %) and 12 (80 %) out of 15 market and farm samples, respectively, using DAL assay, whereas male-specific F+RNA coliphages were detected using the RT-PCR method in 9 (60 %) and 13 (86.6 %) out of 15 samples of market and farm, respectively. Based on the results, only genotype I of male-specific F+RNA coliphages was detected in lettuce samples and no sample tested was positive for other genotypes (II, III, and IV). 相似文献
The decision of intensive care unit (ICU) admission in acute pesticide poisoning is often challenging, especially in developing countries with limited resources. This study was conducted to compare the efficacy of the Acute Physiology and Chronic Health Evaluation II (APACHE II), Modified Early Warning Score (MEWS), and Poisoning Severity Score (PSS) in predicting ICU admission and mortality of acute pesticide-poisoned patients. This prospective cohort study included all patients admitted to Tanta University Poison Control Center with acute pesticide poisoning from the start of March 2018 to the end of March 2019. Patient data, including demographic and toxicological data, clinical examination, laboratory investigation, and score values, were collected on admission. Out of 337 acute pesticide-poisoned patients, 30.5% were admitted to the ICU, including those poisoned with aluminum phosphide (ALP) (81.5%) and organophosphates (OP) (18.5%). Most non-survivors (86.6%) were ALP poisoning. The PSS had the best discriminatory power in predicting ICU admission and mortality, followed by APACHE II and MEWS. However, no significant difference in predicting ICU admission of OP-poisoned patients was detected between the scores. Additionally, no significant difference in mortality prediction of ALP-poisoned patients was found between the PSS and APACHE II. The PSS, APACHE II, and MEWS are good discriminators for outcome prediction of acute pesticide poisoning on admission. Although the PSS showed the best performance, MEWS was simpler, more feasible, and practicable in predicting ICU admission of OP-poisoned patients. Moreover, the APACHE II has better sensitivity for mortality prediction of ALP-poisoned patients.
Environment, Development and Sustainability - Water scarcity poses a global threat to smallholder farmers and crops. Along with population growth, agricultural development, increased urbanization,... 相似文献
The leaching of rare earth elements (REEs) from Egyptian Abu Tartur phosphate rock using phosphoric acid has been examined and was subsequently optimized to better understand if such an approach could be industrially feasible. Preliminary experiments were performed to properly define the design of experiments. Afterward, 24 full factorial design was implemented to optimize the leaching process. Optimum REEs leaching efficiency (96.7 ± 0.9%) was reached with the following conditions: phosphoric acid concentration of 30 wt.-% P2O5, liquid/solid ratio, mL/g, of 5:1, at 20 °C, and 120 min of leaching time. The apparent activation energy of the dissolution of REEs from phosphate rock using the phosphoric acid solution was -19.6 kJ/mol. D2EHPA was subsequently applied as an organic solvent for REEs separation from the acquired leach liquor. REEs stripping and precipitation were conducted, and finally, rare earth oxides with a purity of 88.4% were obtained. The leach liquor was further treated with concentrated sulfuric acid to recover the used phosphoric acid and produce gypsum with a purity of >95% at the same time. A flow diagram for this innovative cleaner production process was developed, and larger-scale experiments are proposed to further understand this promising approach to comprehensive phosphate rock processing.