Shortening hydraulic retention time through effluent recycling: impacts on wastewater treatment and biomass production in microalgal treatment systems

2021 ◽  
Author(s):  
Donna L. Sutherland ◽  
Peter J. Ralph
Keyword(s):  
Wastewater Treatment ◽  
Biomass Production ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Effluent Recycling

The nitrogen removal potential of predenitrification systems in sensitive coastal areas

1995 ◽  
Vol 32 (7) ◽  
pp. 135-142
Author(s):  
E. Görgün ◽  
N. Artan ◽  
D. Orhon ◽  
R. Tasli
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Retention Time ◽  
Treatment Process ◽  
Hydraulic Retention Time ◽  
Domestic Sewage ◽  
Coastal Areas ◽  
Careful Evaluation ◽  
Denitrification Kinetics

Effective nitrogen removal is now required to protect water quality in sensitive coastal areas. This involves a much more difficult treatment process than for conventional domestic sewage as wastewater quantity and quality exhibits severe fluctuations in touristic zones. Activated sludge is currently the most widely used wastewater treatment and may be upgraded as a predenitrification system for nitrogen removal. Interpretation of nitrification and denitrification kinetics reveal a number of useful correlations between significant parameters such as sludge age, C/N ratio, hydraulic retention time, total influent COD. Nitrogen removal potential of predenitrification may be optimized by careful evaluation of wastewater character and the kinetic correlations.

scholarly journals Treatment Of Tofu Industry Wastewater Using Bioreactor Anaerobic-Aerobic And Bioball As Media With Variation Of Hidraulic Retention Time

REAKTOR ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 18-25
Author(s):  
Ariani Dwi Astuti ◽  
Dewi Intania Ayu
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Negative Impact ◽  
Low Cost ◽  
Industrial Effluent ◽  
Organic Loading Rate ◽  
High Concentration ◽  
Small Industries

Tofu which is made by grinding soy bean, generates huge amount of wastewater and thus considered as one of the most polluted food-industrial effluent owing to its high values of organic contents. The small industries of tofu preparation process release the wastewater directly into the water body without being treated first. Prior to discharge this wastewater into the waterbody, the wastewater must be treated to reduce the possibility of negative impact and the contamination of the waterbody. For these small industries, the best alternative of wastewater treatment is one which has the following criteria: easy in operation, low cost operation, low volumes of sludge produced, and can be used in high concentration wastewater. In this research, bioreactor anaerobic-aerobic with media bioball is used. The highest removal efficiency of COD took place in anaerobic zones. Bioreactors were operated with the variations of retention time at 24 hours, 18 hours, and 12 hours. The COD removal efficiency for Hydraulic Retention Time (HRT) of 24 hours, 18 hours and 12 hours were found 90.3% (organic loading rate is 15.1 kg COD/m3.day), 84.4% and 76.3% respectively. The experiment showed that the longer of the hydraulic retention time (HRT), the higher the removal efficiency could be achieved. These occurred because a longer HRT will extend the contact time between wastewater and microorganisms attached. Therefore, microorganisms have a longer time to degrade organic matter in wastewater. Although the removal efficiency in these three-HRT was found high, the effluent of the reactor was still above the effluent standard based on regulation of Ministry of Environmental Permen LH No. 5/2014. Kinetics using Eckenfelder Equation results R2 equal to 0.9991, n equal to 0.293 and K equivalent to 7.3577 mg/L. Keywords: tofu wastewater, anaerobe, aerobe, bioball, wastewater, treatment, attached growth

Symbiotic algal bacterial wastewater treatment: effect of food to microorganism ratio and hydraulic retention time on the process performance

2007 ◽  
Vol 55 (11) ◽  
pp. 165-171 ◽  
Author(s):  
M. Medina ◽  
U. Neis
Keyword(s):  
Growth Rate ◽  
Wastewater Treatment ◽  
Significant Influence ◽  
Retention Time ◽  
Nutrient Removal ◽  
Hydraulic Retention Time ◽  
Process Performance ◽  
Free Swimming ◽  
Effect Of Food ◽  
Total Nitrogen Removal

Algal incorporation into the biomass is important in an innovative wastewater treatment that exploits the symbiosis between bacterial activated sludge and microalgae (Chlorella vulgaris sp. Hamburg). It allows a good and easy algae separation by means of clarification. The effect of process parameters food to microorganisms ratio (F/M) and hydraulic retention time (HRT) on the process performance, evaluated by settleability, microalgae incorporation to biomass and nutrient removal, was studied. HRT hinted at a significant influence in the growth rate of algae, while F/M turned out to be important for stability when algae are incorporated into the biomass. This parameter also affects the total nitrogen removal of the treatment. Stable flocs with incorporated algae and supernatants with low free swimming algae concentrations were obtained at high HRT and low F/M values.

Research on Features of Domestic Wastewater Treatment and Mechanism of Denitrification in Anaerobic MBBR Reactor

2012 ◽  
Vol 455-456 ◽  
pp. 1030-1036
Author(s):  
Hui Zhou Yuan ◽  
Jian Bang Zhao ◽  
Shui Zhou Ke
Keyword(s):  
Wastewater Treatment ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Ammonia Oxidation ◽  
Ph Value ◽  
Domestic Wastewater ◽  
N Concentration ◽  
Domestic Wastewater Treatment ◽  
Anaerobic Ammonia Oxidation ◽  
Nitrification And Denitrification

This paper studied on the treatment of urban domestic wastewater with Anaerobic MBBR in the tropical and subtropical areas in the South of China. The emphasis focused on the effects of the Hydraulic Retention Time (HRT) and pH value to the CODCrconcentration and the NH3-N concentration of the outflow of the reactor. Moreover, the mechanism of denitrification was also explored. The results showed that the mechanism of denitrification of the reactor was found. When HRT was equal to or more than 8h, NH3-N was reduced mainly in the way of short-cut nitrification and denitrification. When HRT was less than 8h, the reactions of short-cut nitrification and denitrification & anaerobic ammonia oxidation both existed in the reactor.

Condition Analysis of Nitrogen Remove from the Mixture of Municipal Wastewater and Fecal Sewage

2011 ◽  
Vol 418-420 ◽  
pp. 717-720
Author(s):  
Ming Yan Shi ◽  
Dong Hua Mo ◽  
Kang Sheng He ◽  
Jing Peng Li
Keyword(s):  
Wastewater Treatment ◽  
Retention Time ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Hydraulic Retention Time ◽  
Treatment Plant ◽  
Reflux Ratio ◽  
Experimental Conditions ◽  
Test Conditions ◽  
Positive Effect

In order to ensure the stable and standard discharge of mixed nitrogen sewage, Guangzhou Datansha Wastewater Treatment Plant has made a test using an inverted A2/ O process, with the actual Wastewater as entry water. When the ratio of mixed fecal sewage is 0.33%, the results showed that, extending the HRT(Hydraulic Retention Time) can help to enhance the effect of removing nitrogen, and HRT should be ensured at least 8 hours under the test conditions. And the increase of the concentration of dissolved oxygen can promote the effect of removing nitrogen ranging from 1.0 to 1.5 mg/L. And the sludge reflux ratio should be remained at 60%. Besides, the growth of sludge age has positive effect on nitrification, so the sludge age should be controlled in more than 20 days under the experimental conditions.

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