Novel biological removal of hazardous chemicals at trace levels

2000 ◽  
Vol 42 (12) ◽  
pp. 49-60 ◽  
Author(s):  
P.L. McCarty
Keyword(s):  
Plug Flow ◽  
Chlorinated Solvents ◽  
Biological Removal ◽  
Sanitary Landfills ◽  
Low Levels ◽  
Trace Chemicals ◽  
Engineered Systems ◽  
Biological Methods ◽  
Aerobic And Anaerobic ◽  
Flow Treatment

Of recent concern is the removal of toxic compounds in wastewaters, soils, and groundwater to concentrations in the low microgram per litre level or less. Threshold limits to bioremediation exist and must be considered in biological treatment schemes to achieve such limits. These limits may be related to reaction kinetics or thermodynamics. Techniques for removing compounds below threshold levels exist that rely on appropriate approaches such as plug flow treatment. Novel biological methods exist for removal of refractory contaminants to low levels. Examples are provided for removal of trace levels of chlorinated solvents, such as tetrachloroethene (PCE) and trichloroethene (TCE), that employ dehalorespiration under anaerobic conditions or cometabolism under aerobic conditions. These approaches are currently being used in engineered systems or through natural attenuation for remediation of soils and groundwater. Successful results offer insights for similar removals of trace chemicals in both aerobic and anaerobic biological systems for treatment of wastewaters and sanitary landfills.

Leachate characterization in semi-aerobic and anaerobic sanitary landfills: A comparative study

2010 ◽  
Vol 91 (12) ◽  
pp. 2608-2614 ◽  
Author(s):  
Shuokr Qarani Aziz ◽  
Hamidi Abdul Aziz ◽  
Mohd Suffian Yusoff ◽  
Mohammed J.K. Bashir ◽  
Muhammad Umar
Keyword(s):  
Comparative Study ◽  
Sanitary Landfills ◽  
Aerobic And Anaerobic

New Developments in Landfill Leachate Treatment

1985 ◽  
Vol 20 (3) ◽  
pp. 1-9
Author(s):  
J.G. Henry
Keyword(s):  
Municipal Wastewater ◽  
Landfill Gas ◽  
High Strength ◽  
Ammonia Nitrogen ◽  
Complex Problem ◽  
Treatment Needs ◽  
Leachate Treatment ◽  
New Developments ◽  
Sanitary Landfills ◽  
Aerobic And Anaerobic

Abstract Treatment of Leachate from sanitary landfills has been found to be a much different and more complex problem than the treatment of municipal wastewater. Greater variability in the characteristics and quantities, of the waste, isolation of the landfill site and the need for simple treatment methods are three reasons why leachate treatment needs special consideration. Typical characteristics of this waste are high strength, a low BOD/COD ratio, limited phosphorus and excessive ammonia nitrogen, along with various toxic contaminants. A number of aerobic and anaerobic methods used to treat leachate are described in this paper and the advantages and shortcomings of each are noted. Supplementary processes including nitrification, nitrogen removal, recirculation and land spraying are also discussed. From experience with these earlier systems it appears that, in the future, more consideration should be given to: equalization of leachate flow, anaerobic rather than aerobic processes, nitrification of the leachate and utilization of landfill gas. Land spraying and recirculation of leachate also warrant wider application.

PROMISING METHODS FOR BIOLOGICAL REMOVAL OF PHOSPHATES FROM WASTEWATER

2021 ◽  
Vol 11 (2) ◽  
pp. 42-47
Author(s):  
Svetlana Yu TEPLYH ◽  
Dmitrii S. BOCHKOV ◽  
Anastasya O. BAZAROVA
Keyword(s):  
Microbial Community ◽  
Biological Removal ◽  
Biological Methods

The article compares the removal of phosphates from wastewater by promising biological methods, namely biotechnologies based on the use of phosphate-accumulating organisms. The microbial community under study gives great hopes for further fundamental studies of the metabolism of phosphate-accumulating organisms, and for improving biotechnologies for purifying wastewater from phosphorus.

The Use of Bacteriocin-Producing Pediococcus acidilactici to Control Postprocessing Listeria monocytogenes Contamination of Frankfurters1

1991 ◽  
Vol 54 (9) ◽  
pp. 681-686 ◽  
Author(s):  
ELAINE D. BERRY ◽  
ROBERT W. HUTKINS ◽  
ROGER W. MANDIGO
Keyword(s):  
Listeria Monocytogenes ◽  
No Reduction ◽  
Initial Level ◽  
Lag Time ◽  
Storage Conditions ◽  
Pediococcus Acidilactici ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Low Levels ◽  
Aerobic And Anaerobic

The ability of a bacteriocin-producing Pediococcus acidilactici to control postprocessing Listeria monocytogenes contamination of frankfurters was examined. Bacteriocin-producing P. acidilactici JD1–23 or its plasmid-cured derivative JD-M and a five-strain composite of L. monocytogenes were inoculated onto fully processed frankfurters. Under normal storage conditions at 4°C under vacuum, L. monocytogenes without added pediococci grew from an initial level of 104 CFU/g to a final level of 106 CFU/g over 60 d, with a lag time of 20–30 d. Under the same conditions, high levels (107 CFU/g) of either pediococcal strain inhibited growth of L. monocytogenes up to 60 d, although no reduction of cells occurred. With low levels of pediococci (103–104 CFU/g), Listeria grew, although the lag time was increased, and a bacteriocin effect was observed on frankfurters inoculated with JD1–23. In additional experiments done at 4°C and 15°C under aerobic and anaerobic conditions, levels of 107–108 CFU/g of either pediococci were observed to control Listeria growth on frankfurters at 15°C under anaerobic conditions for up to 15 d. At 4°C under aerobic conditions, L. monocytogenes grew on frankfurters inoculated with JD-M, while JD1–23 inhibited growth of the organism up to 30 d. At 15°C under aerobic conditions, L. monocytogenes grew in the presence of either pediococci, although a bacteriocin effect was indicated. Package atmosphere was observed to affect L. monocytogenes growth on this product.

scholarly journals Advances in the biological removal of sulphides from aqueous phase in anaerobic processes: A review

2016 ◽  
Vol 24 (1) ◽  
pp. 84-100 ◽  
Author(s):  
Lorna Guerrero ◽  
Silvio Montalvo ◽  
César Huiliñir ◽  
Jose Luis Campos ◽  
Andrea Barahona ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Hydrogen Sulphide ◽  
Microbial Fuel Cells ◽  
Anaerobic Processes ◽  
Biofilm Reactors ◽  
Anaerobic Reactors ◽  
Biological Removal ◽  
Chemical Factors ◽  
Biological Methods ◽  
Physical And Chemical

In this paper, we review the latest developments in biological methods used in the removal of hydrogen sulphide, present in the liquid phase in anaerobic reactors. The toxicity of H2S to methane-forming microorganisms and the problems caused by the presence of this compound in the biogas generated during this process, as well as the main causes of hydrogen sulphide generation in anaerobic processes of wastes are also reviewed. We especially discuss the fundamentals in applying micro-aerobic conditions to remove dissolved hydrogen sulphide from the aqueous phase of an anaerobic reactor. The alternative technology of simultaneous removal of sulphide, nitrate, and organic matter is under recent investigation. Therefore, this review paper includes a study and analysis of the microbiological basis of this technology, the physical and chemical factors that influence the process and the potential application of this technology on different types of wastewaters and situations. Also considered are the fundamentals of both biofilm reactors and microbial fuel cells desulphurization. Because relatively few studies on modeling desulphurisation processes are available, we discuss the advances made in that area.

Designing Constructed Wetlands for Nitrogen Removal

1994 ◽  
Vol 29 (4) ◽  
pp. 15-27 ◽  
Author(s):  
Donald A. Hammer ◽  
Robert L. Knight
Keyword(s):  
Constructed Wetlands ◽  
Deep Water ◽  
Anaerobic Conditions ◽  
Loading Rates ◽  
The North ◽  
N Removal ◽  
North American Data ◽  
Natural Wetlands ◽  
Low Levels ◽  
Aerobic And Anaerobic

Many constructed wetlands adequately treat BOD5, TSS, and bacteria. However, a review of nitrogen (N) data from 52 constructed and natural wetlands in the North American data base confirmed that N removal was variable. Nitrification and denitrification require aerobic and anaerobic conditions. This paper presents case histories of systems that use alternating shallow and deep water zones to create both environments. Regression analysis of N removal and N loadings in 18 shallow-deep water systems suggested that NH4+ loading (kg N/ha/day) could be used to predict effluent NH4+ values. Combinations of shallow water-emergent vegetation and deep water-submergent vegetation with low NH4+ (and TKN) loading rates can produce very low levels of discharged NH4+.

Urease and dehydrogenase activity of alkali and reclaimed soils

Soil Research ◽  
1985 ◽  
Vol 23 (4) ◽  
pp. 661 ◽  
Author(s):  
DLN Rao ◽  
SK Ghai
Keyword(s):  
Organic Carbon ◽  
Marked Improvement ◽  
Enzymatic Activities ◽  
Tree Cover ◽  
Carbon And Nitrogen ◽  
Alkali Soils ◽  
Low Levels ◽  
Biological Methods ◽  
Reclaimed Soils ◽  
Kjeldahl Nitrogen

Alkali soils have low amounts of organic carbon and nitrogen and low levels of urease and dehyrogenase activity. There is a marked improvement in these properties after reclamation by chemical or biological methods. After 12 years, greatest accumulation of organic matter and enzymes was found in soils with a tree cover, followed by those with a grass cover, and it was least in soils reclaimed by application of a chemical amendment (gypsum) followed by cropping. The enzymatic activities were correlated positively with organic carbon and Kjeldahl nitrogen and negatively with pH and CaCO2. Organic carbon accounted for most of the variation in enzymatic activities.

On the Utilization of Biological Methods in Groundwater Treatment

1988 ◽  
Vol 20 (3) ◽  
pp. 129-132 ◽  
Author(s):  
E. Mälkki
Keyword(s):  
Water Treatment ◽  
Treatment Method ◽  
Quality Parameters ◽  
Groundwater Treatment ◽  
Biological Water ◽  
Biological Removal ◽  
Biological Water Treatment ◽  
The Moment ◽  
Biological Methods ◽  
Iron And Manganese

Biological water treatment has been used for more than a century. The processes involved, however, have not been optimally utilized, since knowledge about their character and significance has been insufficient. As conventional water purification techniques developed, the use of biological processes remained in the background until a few decades ago. However, at the moment several biological treatment methods are in use to remove iron and manganese from groundwater, and the future looks promising. The same methods can be used to improve numerous other water quality parameters, e.g. to oxidize reduced nitrogen compounds into nitrates. Biological removal of nitrate, too, will be a future water treatment method.

Temporal trends in mortality and effects of by-catch on common bottlenose dolphins, Tursiops truncatus, in southern Brazil

2010 ◽  
Vol 92 (8) ◽  
pp. 1865-1876 ◽  
Author(s):  
Pedro F. Fruet ◽  
Paul G. Kinas ◽  
Kleber G. da Silva ◽  
Juliana C. Di Tullio ◽  
Daniele S. Monteiro ◽  
...  
Keyword(s):  
Tursiops Truncatus ◽  
Bottlenose Dolphins ◽  
Temporal Trends ◽  
Patos Lagoon ◽  
Biological Removal ◽  
Patos Lagoon Estuary ◽  
Low Levels ◽  
By Catch ◽  
Juvenile Males ◽  
Related Mortality

The mortality of the bottlenose dolphin, Tursiops truncatus, on the southern portion of Rio Grande do Sul State coast was investigated based on 914 beach surveys conducted between 1969 and 2006. A total of 188 stranded bottlenose dolphins were recorded during this period, indicating a 1.8M:1F sex-ratio of those animals sexed (N = 79). Mortality was low in calves, high in juveniles and sub-adults and slightly lower than in adults. The overall mortality was clearly seasonal overlapping with higher fishing efforts in the Patos Lagoon Estuary and adjacent coastal areas, where most individuals washed ashore. Analysis of a continuous 14-year long subset (1993–2006) of the data indicated relatively low levels of mortality between 1995 and 2000 and a marked increase between 2002 and 2005 followed by an apparent drop in 2006. By-catch was responsible for at least 43% of the recorded mortality between 2002 and 2006. Juvenile males were more susceptible to incidental catches. Among females, by-catch of adults represented 75%. Results of a potential biological removal analysis suggest that current levels of fishing-related mortality are unsustainable for the small resident population of bottlenose dolphins that inhabits the Patos Lagoon Estuary, and that this population may be declining.

Sign in / Sign up

Export Citation Format

Share Document