Heavy metals in waters and sediments of Port Phillip Bay, Australia

1999 ◽  
Vol 50 (6) ◽  
pp. 503 ◽  
Author(s):  
G. J. Fabris ◽  
C. A. Monahan ◽  
G. E. Batley

Despite significant inputs of heavy metals from rivers, creeks and drains and a major sewage treatment plant to Port Phillip Bay, Victoria, Australia, attenuation processes in the water column are such that metal concentrations in the bay waters are comparable to uncontaminated estuaries elsewhere in the world. Sedimentation appeared to be largely responsible for metal removal, with strong correlations between particulate metals and iron in input waters sampled over a storm event. Storm events contributed between 9 (Zn) and 21 (Cr) times the metal loads that enter the bay during low flow conditions. Although metal accumulations in sediments are below guideline concentrations in the major deposition zones, they are highest close to input sources. A unique feature of bay waters was the high concentration of dissolved arsenic (2.8 µg L–1). The source appears to be natural sediment mineralogy, and sediment cores were found to be depleted in arsenic near the sedimentŒwater interface. Overall, the findings suggested that current heavy metal inputs do not represent a threat to the health of the bay.

2021 ◽  
Author(s):  
Safika Akter

Bioleaching has been proven to be a promising technology for removing heavy metals from the sewage sludge over many years. The main objective of this research is to evaluate the bioleaching process for the simultaneous reduction of three heavy metals - copper(Cu), cadmium(Cd), zinc(Zn) and total coliform from the sewage sludge of the Ashbridges Bay Treatment Plant (ABTP). Bioleaching was carried out with adapted activated sludge containing high concentration of iron oxidizing bacteria T. ferrooxidans using ferrous sulphate as a substrate without adjusting the sludge initial pH to about 4 with acid. The results demonstreated that simultaneous metal removal efficiencies of Cu, Zn were 70% and 74% for Cd respectively after 10 days of bioleaching. The final pH and ORP were found 2.44 and 533 respectively. After this research, it was also observed that the process of bioleaching by T. ferrooxidans is very efficient for the reduction of total coliform from the sludge. This proces allows a considerable reduction in total coliform (3-4 log removal) for the activated sludge examined over a 10 day period.


2021 ◽  
Author(s):  
Safika Akter

Bioleaching has been proven to be a promising technology for removing heavy metals from the sewage sludge over many years. The main objective of this research is to evaluate the bioleaching process for the simultaneous reduction of three heavy metals - copper(Cu), cadmium(Cd), zinc(Zn) and total coliform from the sewage sludge of the Ashbridges Bay Treatment Plant (ABTP). Bioleaching was carried out with adapted activated sludge containing high concentration of iron oxidizing bacteria T. ferrooxidans using ferrous sulphate as a substrate without adjusting the sludge initial pH to about 4 with acid. The results demonstreated that simultaneous metal removal efficiencies of Cu, Zn were 70% and 74% for Cd respectively after 10 days of bioleaching. The final pH and ORP were found 2.44 and 533 respectively. After this research, it was also observed that the process of bioleaching by T. ferrooxidans is very efficient for the reduction of total coliform from the sludge. This proces allows a considerable reduction in total coliform (3-4 log removal) for the activated sludge examined over a 10 day period.


2017 ◽  
Vol 1 (1) ◽  
pp. 46-55 ◽  
Author(s):  
Athar Hussain ◽  
Manjeeta Priyadarshi ◽  
Saif Said ◽  
Suraj Negi

Most of the industrial sewage effluents used for irrigation contains heavy metals which cause toxicity to crop plants as the soils are able to accumulate heavy metal for many years. The vegetables grown for the present study were irrigated with treated wastewater brought from a nearby full-scale sewage treatment plant at different compositions along with tap water as a control. The concentration levels of the Cd, Co, Cu, Mn and Zn in the soil were found to below the toxic limits as prescribed in literature. Daily Intake Metals (DIM) values suggest that the consumption of plants grown in treated wastewater and tap water is nearly free of risks, as the dietary intake limits of Cu, Fe, Zn and Mn. The Enrichment Factor for the treated wastewater irrigated soil was found in order Zn> Ni> Pb> Cr> Cu> Co> Mn> Cd. Thus, treated wastewater can be effectively used for irrigation. This will have twofold significant environmental advantages: (1) helpful to reduce the groundwater usage for irrigation and (2) helpful to reduce the stress on surface water resources.


1997 ◽  
Vol 35 (8) ◽  
pp. 231-238 ◽  
Author(s):  
Tay Joo Hwa ◽  
S. Jeyaseelan

Conditioning of sludges improves dewatering characteristics and reduces the quantity of sludge to be handled. Anaerobic digested sludge collected from a sewage treatment plant contained 1.8% to 8% oil. The increase of specific resistance and capillary suction time (CST) with increasing oil content observed in these samples indicates the interference of oil in dewatering. It has been found that addition of municipal solid wastes incinerator fly ash decreases the specific resistances and capillary suction times of oily sludges rapidly up to 3% dosage. Beyond 3% fly ash, the decrease is less significant and the solids content in the sludge cake increases. This optimum dosage remains the same for sludges with varying oil contents from 1.8% to 12%. The total suspended solids of filtrate decreases with fly ash dosage but the toxic concentrations of heavy metals increases considerably. However at the optimum dosage of 3%, concentrations of heavy metals are within the limits for discharging into the sewers. The correlations of CST with the dewatering characteristics such as specific resistance, filter yield and corrected filter yield are established. These correlations can be used to obtain a quick prediction on dewaterability.


2008 ◽  
Vol 58 (5) ◽  
pp. 1101-1106
Author(s):  
Pichiah Saravanan ◽  
K. Pakshirajan ◽  
P. K. Saha

An indigenous mixed culture of microorganisms, isolated from a sewage treatment plant, was investigated for its potential to simultaneously degrade phenol and m-cresol during its growth in batch shake flasks. 22 full factorial designs with the two substrates as the factors, at two different levels and two different initial concentration ranges, were employed to carry out the biodegradation experiments. For complete utilisation of phenol and m-cresol, the culture took a minimum duration of 21 hrs at their low concentration of 100 mg/L each, and a maximum duration of 187 hrs at high concentration of 600 mg/L each in the multisubstrate system. The biodegradation results also showed that the presence of phenol in low concentration range (100–300 mg/L did not inhibit m-cresol biodegradation; on the other hand, presence of m-cresol inhibited phenol biodegradation by the culture. Moreover, irrespective of the concentrations used, phenol was degraded preferentially and earlier than m-cresol. During the culture growth, a lag phase was observed above a combined concentration of 500 mg/L i.e., 200 mg/L m-cresol and 300 mg/L of phenol and above). Statistical analysis of the specific growth rate of the culture in the multisubstrate system was also performed in the form of ANOVA and Student ‘t’ test, which gave good interpretation in terms of main and interaction effects of the substrates.


1973 ◽  
Vol 2 (4) ◽  
pp. 473-482 ◽  
Author(s):  
J. C. Van Loon ◽  
J. Lichwa ◽  
D. Ruttan ◽  
J. Kinrade

1992 ◽  
Vol 25 (10) ◽  
pp. 55-67 ◽  
Author(s):  
R. C. Squires

The performance of Exxflow, a patented form of crossflow microfiltration, treating industrial wastewaters containing mixed heavy metals discharged by two types of industry is quantified and compared with the traditional technologies used for such treatment. Pilot trial results using Exxflow are shown and compared to the performance of the full scale plants now operating on these effluents. The operating costs of the Exxflow process are estimated for the two plants. One of which has been operating for 18 months and the other about 4 months. The Exxflow process is described and improvements which are being developed to lower the operating costs are presented. It is shown that industrial effluents containing mixed heavy metals are very effectively treated by the Exxflow process and since the installation of the plants the treated effluent has been of a quality suitable for discharge to the River Thames in one case and to a sewage treatment plant in the other. Unlike other processes, Exxflow has shown that it can successfully treat effluent containing mixed metals and that removal of antimony from mixed metal waste waters is affected by the concentration of sodium sulphate in the wastewater.


Author(s):  
R. Edgecock ◽  
V. V. Bratishko ◽  
I. V. Zinchenko ◽  
S. H. Karpus ◽  
D. O. Milko ◽  
...  

Annotation Purpose. Summarize the regulatory and technological requirements for the production of organic (organo-mineral) fertilizers on the base of sewage sludge. Methods. Analysis and generalization of the requirements of regulatory documents on the management of organic waste and their use as raw materials for the production of organic fertilizers and soil improvers. Results. The current legislative, departmental and regulatory documentary base in Ukraine concerning the treatment of sediment resulting from biological sewage treatment at municipal wastewater treatment plants for its further use in agriculture as fertilizers is analysed. Indicators are identified and analysed to determine the possibility, feasibility, efficiency and scope of organic fertilizers produced using sewage sludge. The analysis of changes in the content of organic matter and total nitrogen in the sewage sludge during its storage at the sewage treatment plant sites is presented. The technological feasibility of using sludge of different shelf life in composting production has been determined. Conclusions 1. The regulatory framework of Ukraine contains a sufficiently complete list of indicators that should be met by organic raw materials (sewage sludge) for further use as organic fertilizers. Some of these indicators – bio security and heavy metals content – can be improved in the composting process of fertilizers. 2. Fresh sediment, as well as sediment accumulated in the last late autumn and winter periods, is of main value for use as a raw material in the production of organic fertilizers. 3. The use in the production of compost sludge stored on sludge sites for a period of half a year or more requires special control of the process of decontamination. In this case, it is advisable to use additional means of wastewater decontamination. Keywords: heavy metals, manure, humus, decontamination, composting, organic fertilizers, sewage sludge.


1990 ◽  
Vol 22 (12) ◽  
pp. 249-258 ◽  
Author(s):  
T. R. Bridle ◽  
I. Hammerton ◽  
C. K. Hertle

A four month pilot plant program, evaluating all unit operations comprising an integrated Oil from Sludge (OFS) plant has been successfully completed for the Sydney Water Board. The unit operations of sludge dewatering, drying and conversion to oil in the patented OFS reactor system were set up at the Malabar Sewage Treatment Plant in Sydney. Pilot testing of the char combustor was conducted off site. Extensive heavy metal and organochlorine monitoring across each unit operation has revealed the following information. There is no loss of contaminants across the dewatering and drying operations. With the exception of arsenic and mercury, all heavy metals fed to the OFS reactor are retained in the char. Greater than 75% of PCB's and 85% of HCB present in sludge are destroyed in the OFS reactor. Greater than 99.7% of the heavy metals fed to the fluid bed combustor are retained in the ash (with exception of mercury, which reported 3% in the flue gas). The FBC ash is classified non-hazardous, using the Toxic Characteristic Leaching Procedure.No organochlorines were detected in the dryer or FBC off-gases. The OFS technology offers decoupling of heavy metal and organochlorine control mechanisms, thus allowing each to be optimally controlled.


2004 ◽  
Vol 46 (6) ◽  
pp. 309-313 ◽  
Author(s):  
Luciana Urbano Santos ◽  
Taís Rondello Bonatti ◽  
Romeu Cantusio Neto ◽  
Regina Maura Bueno Franco

Giardia and Cryptosporidium have caused several outbreaks of gastroenteritis in humans associated with drinking water. Contaminated sewage effluents are recognized as a potential source of waterborne protozoa. Due to the lack of studies about the occurrence of these parasites in sewage samples in Brazil, we compared the efficiency of two procedures for concentrating cysts and oocysts in activated sludge samples of one sewage treatment plant. For this, the samples were submitted to i) concentration by the ether clarification procedure (ECP) and to ii) purification by sucrose flotation method (SFM) and aliquots of the pellets were examined by immunofluorescence. Giardia cysts were present in all samples (100.0%; n = 8) when using ECP and kit 1 reagents, while kit 2 resulted in six positive samples (85.7%; n = 7). As for SFM, cysts were detected in 75.0% and 100.0% of these samples (for kit 1 and 2, respectively). Regarding Cryptosporidium, two samples (25.0%; kit 1 and 28.5% for kit 2) were detected positive by using ECP, while for SFM, only one sample (examined by kit 1) was positive (12.5%). The results of the control trial revealed Giardia and Cryptosporidium recovery efficiency rates for ECP of 54.5% and 9.6%, while SFM was 10.5% and 3.2%, respectively. Considering the high concentration detected, a previous evaluation of the activated sludge before its application in agriculture is recommended and with some improvement, ECP would be an appropriate simple technique for protozoa detection in sewage samples.


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