Topic
Hydraulic retention time
About: Hydraulic retention time is a research topic. Over the lifetime, 6406 publications have been published within this topic receiving 151005 citations.
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TL;DR: Increased temperature had no effect on the steady-state COD removal efficiency with both reactors stabilized at 68-75%.
106 citations
TL;DR: The effects and mechanisms of influent composition, process configuration, operating parameters and environmental condition to the change of microbial community structure and process performance (nitrification, denitrification, biological phosphorus removal, organics mineralization and utilization, etc.) are critically reviewed.
106 citations
TL;DR: In this paper, the results from batch assays led to the addition of cobalt to reach a concentration of 0.2 mg L −1, which made it possible to increase the organic loading rate (OLR) above that in a parallel process not receiving any extra cobalt.
Abstract: Batch assays were performed with samples from a silage-fed mesophilic biogas process accumulating acetate to examine if the addition of single trace elements (iron, nickel, cobalt and molybdenum) or a mixture of trace elements could improve the process. The results from the batch assays led to the addition of cobalt to reach a concentration of 0.2 mg L −1 . This made it possible to increase the organic loading rate (OLR) above that in a parallel process not receiving any extra cobalt. Problems with low gas production and decreasing pH were overcome by the daily supply of this single element in small amounts. Acetate conversion to methane was improved, which was confirmed by increased specific methanogenic activity (SMA) with acetate as a substrate. As a consequence, an OLR of 7.0 g VS L −1 day −1 was achieved at a hydraulic retention time (HRT) of 20 days with an equivalent increase in methane production. Without cobalt addition, an OLR of 5.0 g VS L −1 day −1 with an HRT of 20 days was reached after 70 weeks operation.
106 citations
TL;DR: In this article, the effect of various parameters such as pH, voltage, hydraulic retention time (HRT), and number of aluminum plates between the anode and cathode on efficiency of treatment are investigated.
Abstract: BACKGROUND: The present study describes an electrocoagulation process for treating laundry waste-water using aluminum plates. The effect of various parameters such pH, voltage, hydraulic retention time (HRT), and number of aluminum plates between the anode and cathode on efficiency of treatment are investigated.
RESULTS: Experimental results showed that by increasing HRT, treatment efficiency increases but beyond 45 min changes are negligible. Among the results for chemical oxygen demand (COD), phosphorus, detergent, colour and turbidity, the lowest decrease was found for phosphorus. The larger the HRT, the greater the electrical current needed to achieve constant voltage and temperature in the system. The pH of the influent is a very significant variable which affects the treatment of laundry waste-water considerably, the optimal range being 6.0–8.0. In addition, it was found that the pH increases from 8.3 to more than 10 over the first hour of treatment after which the pH remains relatively constant. Finally, kinetic analysis indicates that the adsorption system obeys a second-order kinetic model.
CONCLUSION: The aluminum hydroxide generated in the cell decreases the concentration of pollutants in laundry waste-water to a permissible level. It is concluded that, compared with other treatment processes, electrocoagulation is more effective in treating laundry waste-water under appropriate conditions. Copyright © 2011 Society of Chemical Industry
106 citations
TL;DR: In this article, the performance of an anaerobic baffled reactor (ABR, 10 l and eight compartments) treating a dilute wastewater (500 mg COD/l) was studied.
106 citations