EFFECTS OF HYDRAULIC RETENTION TIME ON PERFORMANCE AND EFFLUENT ODOR OF CONVENTIONAL AND FIXED-FILM ANAEROBIC DIGESTERS FED DAIRY MANURE WASTEWATERS

1997 ◽  
Vol 40 (5) ◽  
pp. 1449-1455 ◽  
Author(s):  
W. J. Powers ◽  
A. C. Wilkie ◽  
H. H. Van Horn ◽  
R. A. Nordstedt
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Dairy Manure ◽  
Anaerobic Digesters ◽  
Fixed Film

scholarly journals Efficiency of the work of almond shells as biological carriers in activated sludge aeration tanks: كفاءة عمل قشور اللوز كحوامل بيولوجية في أحواض التهوية بالحمأة المنشطة

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Raghad Salim Al-Shalabi, Naeima Ajib, Mahmoud Fattamah
Keyword(s):  
Activated Sludge ◽  
Removal Efficiency ◽  
Retention Time ◽  
Suspended Solids ◽  
Hydraulic Retention Time ◽  
Aeration Tank ◽  
Sludge Treatment ◽  
Mixed Liquor ◽  
Conventional Activated Sludge ◽  
Fixed Film

Based on the interest in environmentally friendly materials for wastewater treatment, this research is aimed at evaluating the efficiency of almond shells work as biological carriers in activated sludge aeration tanks, known as the integrated fixed-film activated sludge treatment, a hybrid tank with attached growth and suspended growth is obtained. Almond shells were placed at 7% of the size of the aeration tank throughout the experiment period for about 4 months with a number of indicators such as hydraulic retention time and mixed liquor suspended solids. Two sets of experiments were performed, the first group with a constant hydraulic retention time ( HRT= 4 hours), and mixed liquor suspended solids was changed (500-1000-2000-3000 mg/ L), with the best removal efficiency at MLSS = 2000 mg/ l, by 91.3% and 92.1% for COD and SS respectively. The optimal MLSS concentration was adopted for the second group of experiments where HRT was increased to 5 and 6 hours. As a result, the best chain was found to be MLSS = 2000 mg/ l and HRT = 5 hours, with a removal efficiency of 93.4% and 93.9% for COD and SS respectively. As a result, the rate of return activated sludge was reduced from 100% to 60% and the rate of inflow into the aeration tank was increased due to the reduction HRT from 6 hours to 5 hours compared to conventional activated sludge treatment.

scholarly journals Possibilities of Obtaining Biogas from Manure and Amaranth

2021 ◽  
Vol 31 (3) ◽  
pp. 336-348
Author(s):  
Julia V. Karaeva ◽  
Svetlana S. Timofeeva
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Experimental Studies ◽  
Amaranthus Retroflexus ◽  
Dairy Manure ◽  
Organic Load ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Kinetics Of

Introduction. The use of biomass allows increasing the rate of biogas formation and its specific yield. This work aims to study the kinetics of methanogenesis and determine the optimal duration of digestion and organic load, which are the main indicators of the technological process of biogas formation. Materials and Methods. The substrate (dairy manure, biomass of amaranth) was the study object. Experimental studies were carried out using a laboratory biogas plant. The computer program (certificate No. 2018662045) was used to obtain modified Gompertz models describing the kinetics of biogas formation. Based on the obtained data, the hydraulic retention time and organic loading rate (the key parameters in the design of biogas plants were determined). Results. The paper presents the experimental studies results of the biogas formation kinetics when using dry amaranth biomass. The Gompertz mathematical models were obtained. Methane-tank control parameters (hydraulic retention time and organic loading rate) were obtained for anaerobic digestion of a new substrate. Discussion and Conclusion. The use of new co-substrate Amaranthus retroflexus L. allowed increasing the specific biogas yield from dairy manure by 52.2 % and the ultrasonic pre-treatment in combination with the herbal supplement by 89.1 %. The optimal hydraulic retention time value was 10 days and organic loading rate was 4.1 kg of volatile solids per m3 of digester per day.

Biological Phosphorus Removal in Fixed Films Reactors

1992 ◽  
Vol 25 (12) ◽  
pp. 165-174 ◽  
Author(s):  
R. Franci Gonçalves ◽  
F. Rogalla
Keyword(s):  
Retention Time ◽  
Phosphorus Removal ◽  
Hydraulic Retention Time ◽  
Phosphorus Release ◽  
Organic Substrate ◽  
Biological Phosphorus Removal ◽  
Removal Process ◽  
Fixed Film ◽  
Film Reactor ◽  
Biological Phosphorus

Possible procedures to achieve biological phosphorus removal in a fixed film reactor are discussed and the feasibility of phosphorus removal process in a fixed film reactor under continous flow is demonstrated. The behaviour of an upflow aerated filter operating under continuous feed and alternate aerobic/anaerobic conditions is analyzed. The influence of the duration of anaerobic and aerobic contact periods and of organic substrate loadings on the phosphorus removal process is verified. During the anaerobic state, the longer the duration, or the higher the substrate load, the better the phosphorus release and consequently the higher the uptake in the aerobic phase. The excess of accumulated phosphorus in the aerobic phase over released phosphorus in the anaerobic phase approaches 33 %. For each mg of phosphorus released, 5 mg filtered COD are consumed. Continuous phosphorus removal on two biofilters in series was performed by alternating aeration conditions, always introducing the influent to the anaerobic reactor.The tests carried out on laboratory scale showed that this system carrys out complete nitrification and removal of 80% of the phosphorus with a maximum hydraulic retention time of 5 hours. The hydraulic retention time and the residence time of the biomass in the reactor are independent and, therefore, the time the bacteria are exposed to alternate A/O conditions can be optimized. The very low concentrations of suspended solids in the effluent of the biofilter enable residual levels below 1 mg PO4-P/l to be obtained. Further investigations are carried out on full scale and to introduce denitrification in the same reactor.

Effect of the pH influent conditions in fixed-film reactors for anaerobic thermophilic treatment of wine-distillery wastewater

2005 ◽  
Vol 51 (1) ◽  
pp. 183-189 ◽  
Author(s):  
M. Pérez-García ◽  
L.I. Romero-García ◽  
R. Rodríguez-Cano ◽  
D. Sales-Márquez
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Oxygen Demand ◽  
High Rate ◽  
Organic Load ◽  
Substrate Removal ◽  
Load Rate ◽  
Fixed Film ◽  
Thermophilic Conditions ◽  
Distillery Wastewater

In anaerobic treatments, the pH conditions affect the efficacy and operation of the process. The main purpose of this research is to compare the effect of the pH influent on the performance of a high rate technology at laboratory scale, upflow anaerobic fixed-film reactor, treating distillery wastewater (wine vinasses) in thermophilic conditions. The results obtained shown that the pH influent influences the performance of the biodegradation process: the depurative efficiency is higher for the operation with alkaline influent. The operation with acid influent allows us to operate at organic loading rates (OLR) around 5.6 kgCOD/m3/d (hydraulic retention time: 1.5 days), maintaining total Chemical Oxygen Demand removals (CODr) of 77.2%; the operation with alkaline influent allows total CODr of 76.8% working at OLR around 10.5 kgCOD/m3/d. The greatest efficiency of substrate removal was 87.5% for OLR 3.2 kgCOD/m3/d and hydraulic retention time of 4.0 days operating with alkaline influent. Therefore, the operation with alkaline influent implicates senior levels of purifying efficiency for similar organic load rate.

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.

Evaluation of a tropical single-cell waste stabilization pond system for irrigation

1995 ◽  
Vol 31 (12) ◽  
pp. 267-273 ◽  
Author(s):  
B. S. O. Ceballos ◽  
A. Konig ◽  
B. Lomans ◽  
A. B. Athayde ◽  
H. W. Pearson
Keyword(s):  
Single Cell ◽  
Removal Efficiency ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Full Scale ◽  
Waste Stabilization Pond ◽  
North East ◽  
Helminth Eggs ◽  
Waste Stabilization ◽  
Better Than

A single full-scale primary facultative pond in Sapé, north-east Brazil was monitored for performance and efficiency. The pond had a hydraulic retention time of 61 days and achieved a 95% BOD5 removal efficiency and had no helminth eggs in the effluent. The effluent failed to meet the WHO faecal coliform guideline for unrestricted irrigation. The pond was dominated by the cyanobacterium Microcystis and gave better than predicted orthophosphate removal. Details of how the system could be simply upgraded utilizing the same land are discussed.

Sign in / Sign up

Export Citation Format

Share Document