Enrich waste activated sludge digestibility via natural enzyme supplementation

Upgrading of low biodegradable waste activated sludge (WAS) accomplished through supplement the hydrolysis step with natural enzymes source. Whereas, WAS is rich in particulate fractions in terms of total chemical oxygen demand (tCOD), total suspended solids (TSS) and volatile suspended solids (VSS) of 15.78, 14.92 and 12.15 g/L, respectively. Therefore, carica papaya enzymes were utilized to break down the peptide ponds in protein molecules such as papain and protease, as well as, lipases that catalyzed the degradation of lipids. The optimum mixture between papain, protease, and lipase enzymes was found to be 3: 1: 2 while the optimum enzyme concentration was 8%. This conditions was attributed to enhance the H2 productivity form WAS by 97.8

Investigation of operational conditions for the removal of methylene blue by Fenton Reaction

Fenton reaction has been concerned by many researchersdue to easy operation and effective degradation of bioresistantorganics. This study aims to investigate the effect ofthe operational conditions on the effectiveness of Fenton’sprocess for the decolorization of methylene blue.The influenceof methylene blue, pH, dose of H2O2 , ferrous sulfateconcentration from the wastewater were studied. Experimentshave shown that highly affect by the value of pH, Laboratoryexperiment conducted in the lab proved that pH should bebetween 3 - 4 to give the best results, It also proved that theincreasing of the dose of both hydrogen peroxide and ferroussulfate enhanced the removal efficiency of MB

Bio-H2 conversion of wastewater via hybrid dark/photo fermentation reactor

Hydrogen energy is a clean source for liveliness betterthan fossil fuel that has hazardous effects on the environmentand atmosphere. Food wastes and organics in the sewage sludgeare a promising sustainable and renewable source for hydrogenproduction where amalgamation of waste treatment and energyproduction would be more than one benefit expressed intreatment of organic pollutants and energy generation.Discovering biohydrogen production from industrialwastewater by dark and photo fermentation was the main aimof this paper. The biogas produced was composed of H2 andCO2, and the maximum H2 content was 25.94%. This ratio wasachieved at batch configuration system and initial pH 6.2 withstarch concentration 15 g/l. Cause of using dark fermentationeffluent (DFE) was used as substrate for A Rhodobactercapsulatus strain and a clostridium culture were cultivated toproduce hydrogen under different light-dark cycles. Acetic andbutyric acids decreased due to first and second photo stages by21.9% and 4.1 % respectively. Maximum hydrogen yield was470.9 ml H2/mol VFAs

Comparative analysis of common full scale reactors for dry anaerobic digestion process

Organic solid wastes are produced with large amount wherever there are human activities. However, improper treated organic wastes made them as sources of diseases. On the other hand, these fractions contain nutrients and energy, so they have also valuable resources. As a result, exploring their potential as an energy source can be accomplish via anaerobic digestion process, in which, organics converted into hydrogen, methane and/or ethanol. Therefore, this manuscript introduces an overview of the common applied types of reactor that can handle these types of wastes in their solid state and recover them in term of biogas, as well as, stabilize the produced digestate to bio-fertilizers by compositing approach. A comparison also listed to demonstrate the optimum operational conditions and expected amount of biogas from each type

Assessment of Thermal Comfort in Operating Rooms Using PMV-PPD Model

Operating rooms (ORs) are the most critical and expensive sector of healthcare facilities. The air conditioning system is designed to provide a well-controlled indoor air quality (IAQ). This design guarantees a perfect infection control and a good thermal comfort of patient and operating staff.This paper aims to analyze and evaluate indoor thermal comfort at different cases to assign the proper inlet air temperature to the OR. The predicted mean vote (PMV) and the predicted percentage dissatisfied (PPD) models in accordance with ISO 7730 were used for this study.Field measurements were first carried out in an OR at Kafr El-Sheikh educational hospital to get the thermal environment parameters. These parameters are required to determine the thermal comfort indices namely (PMV & PPD). Four different cases of supplied air temperature 17.5, 18.5, 19.5 and 20.5oC were studied and compared through 105 measuring points distributed in the operating room. The PMV and PPD indices were computed at each case for three groups of medical staff: surgeons (metabolic rate equal to 120 W/m2), nurses and surgeon\u27s assistants (100 W/m2), anesthetists (70 W/m2).The results revealed that inlet air temperature has a minor effect on the air velocities and airflow patterns inside the OR at the same air change rate. For the current ventilation system, it is difficult to create a very comfortable work conditions for all operating staff at the same time due to their different thermal requirements. It was concluded that a supplied air temperature of 18.5oC provides almost comfortable conditions for all surgical staff