Determination of natural radionuclides in waste generated in the potable water treatment plants of the Zona da Mata of the state of Pernambuco- Brazil

2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
Adriana Muniz De Almeida Albuquerque

The water purification procedure aims to obtain a product appropriate for human consumption, minimizing the presence of contaminants and toxic substances present in the water. Among these contaminants, some radionuclides of natural origin, such as uranium, thorium and their descendants, have been identified. Studies have shown that the stages of purification are quite effective in removing the radionuclides contained in water. The removal is due to co-precipitation of the radionuclides with the suspended materials and the precipitated material is accumulated and characterized as a Technologically Concentrated Natural Occurrence Radioactive Material (TENORM) by the United States Environmental Protection Agency (USEPA). This residue can present significant levels of radioactivity and, when discarded in the environment without any treatment, can generate a problem of environmental impact and a risk to the health of the population. In this way, some gamma emitters of the series of U, Th and the K-40 were determined in the residues generated at the Potable Water Treatment Plants – PWTPs in six municipalities of Pernambuco. The results obtain corroborate the classification of the residues generated in the PWTPs as concentrators of the radioactive components contained in the water supplied to the system and reinforce the need for the release to the environment, which is the usual way of disposal of this waste, to be carried out only after considering the radiological protection standards established.

1995 ◽  
Vol 31 (3-4) ◽  
pp. 327-340
Author(s):  
Steven R. Arnold ◽  
Thomas P. Grubb ◽  
Peter J. Harvey

The use of Dissolved Air Flotation (DAF) as a solids/liquid separation process in water treatment has been an effective alternative to sedimentation for 70 years. The process was initially applied for removal of materials which had a specific gravity less than water, such as fats, oils, fibers, and grease. DAF installations expanded in the late 1960s to wastewater and potable water treatment. Today, Dissolved Air Flotation is utilized for a wide variety of water and wastewater applications. DAF is applied extensively for wastewater sludge thickening and it is widely accepted in Scandinavia and the United Kingdom for potable water treatment. It has also gained a foothold in the United States with the start up of a 7.5 mgd (28.4 Ml/d) potable water flotation plant at New Castle, New York. The goal of this paper is to present recent applications of Dissolved Air Flotation technology on a variety of raw water sources. Descriptions and general design parameters of a typical flotation and a proprietary combined flotation and filtration process will be discussed.


2010 ◽  
Vol 10 (5) ◽  
pp. 765-770 ◽  
Author(s):  
S. N. Kommineni ◽  
J. Bryck ◽  
C. Stringer ◽  
C. Stevens ◽  
N. Meyers ◽  
...  

Historically, low-pressure membranes (microfiltration (MF) and ultrafiltration (UF)) used in potable water treatment are made of polymers (polysulfone (PS), polypropylene (PP), polyethersulfone (PES), polyvinylidene fluoride (PVDF) etc). Recently, membranes made of ceramic materials (aluminium oxide) have been developed by MetaWater (Japan), Kubota (Japan) and others and is being marketed in the United States (US) by Krüger, Inc. (Cary, NC). Ceramic membranes offer several potential advantages over polymeric membranes, including higher mechanical robustness and ability to handle higher loading of particulates, higher resistance to oxidants and membrane cleaning chemicals, higher membrane integrity, longer service life and compact footprint. The authors conducted collaborative evaluations of this emerging technology at two different places; (i) Elm Fork Water Treatment Plant (WTP) of Dallas Water Utilities (DWU), Dallas, Texas, USA and (ii) Graham Mesa WTP, City of Rifle, Rifle, Colorado, USA. The evaluations included pilot testing of ceramic membranes in direct filtration mode (i.e. without clarification) and with coagulant addition. The water streams that were pilot tested at Elm Fork WTP included Trinity River water, spent filter backwash wastewater and lagoon recycle water (spent filter backwash water combined with clarifier blow down water). The City of Rifle pilot testing was conducted on Colorado River water. This paper presents the key results of these two pilot studies. Results of pilot testing were used to define the potential membrane flux, backwash protocols (interval and duration), chemical enhanced backwash (CEB) and clean-in-place (CIP) protocols. Pilot test results and engineering judgment were used for developing concept-level sizing and outlining parameters for future evaluation. This paper will discuss the key technical and economic considerations of the emerging treatment technology and its potential applications for potable water treatment. This paper will be of interest to water providers that are considering alternatives to treat challenging source waters (waters with high particulates and under heavy microbial influence), build new compact water treatment plants, increase plant capacity through membrane retrofits and treat recycle streams at existing WTPs.


Author(s):  
Oscar Orlando Ortíz Rodriguez ◽  
Raquel Amanda Villamizar-Gallardo ◽  
Rafael Guilhermo García

There is currently great concern about the processes that directly or indirectly contribute to the potential for global warming, such as stratospheric ozone depletion or acidification. In this context, and provided that treated water is a basic public utility in urban centers around the world as well as in some rural areas, its impact on the environment is of great interest. Therefore, this study applied the environmental methodology of Life Cycle Assessment (LCA) to evaluate the environmental loads of four potable water treatment plants (PWTPs) located in northeastern Colombia following the international guidelines delineated in ISO 14040. The different stages of the drinking water process were thoroughly assessed, from the catchment point through pumping to the distribution network. The functional unit was defined as 1 m3 of drinking water produced at the plant. The data were analyzed through the database Ecoinvent v.3.01, and modeled and processed in the software LCA-Data Manager. The results showed that in plants PLA-CA and PLA-PO, the flocculation process has the highest environmental load, which is mostly attributable to the coagulant agent, with a range between 47-73% of the total impact. In plants PLA-TON and PLA-BOS, electricity consumption was identified as the greatest impact source, with percentages ranging from 67 to 85%. Treatment processes and techniques, bioclimatic conditions and culturally driven consumption behavior varied from region to region. Furthermore, changes in treatment processes and techniques are likely to affect the environment during all stages of a plant’s operational cycle.


2002 ◽  
Vol 2 (5-6) ◽  
pp. 9-16 ◽  
Author(s):  
G. Evans ◽  
P. Dennis ◽  
M. Cousins ◽  
R. Campbell

The aim of this study was to investigate the use of recycled crushed glass as a filtration medium for municipal potable water treatment plants. It evaluated the main physical parameters of recycled glass and its performance in a potable water treatment application. Pilot-plant testing was used to compare the performance of recycled glass to a typical sand filter medium in a conventional treatment process. Laboratory analysis was used to determine media characteristics. Pilot-plant testing determined that the filtration performance of the glass medium was similar to that of a typical sand medium of similar effective size and uniformity under all conditions tested. The glass medium had the benefit of taking 10-15% longer than the sand to reach particle breakthrough. The glass also appeared to accumulate headloss in most runs at a slightly lower rate than the sand. Backwashing observed during pilot-plant testing also showed that the glass expanded more than the sand under the same backwash water rates. This was noted to be a potential benefit to installations that have low backwash water flow.


Author(s):  
Ali Ekhlasi Nia ◽  
Harrison Bull ◽  
Mohsen Asadi ◽  
Kerry McPhedran

Wastewater stabilization ponds (WSPs) are commonly used to reduce wastewater metal(loid) concentrations from drinking water treatment plants (DWTPs) through sedimentation. However, this results in increased sediment concentrations that can be released back into the overlying water. Thus, our goal was to evaluate the WSP metal(loid)s occurrence and leaching potential. Currently, a Saskatchewan based DWTP’s WSP system was investigated given historically elevated effluent As and Fe concentrations. The WSP consists of five ponds that were sampled on six occasions in 2019 and 2020. In addition, sediments were used in laboratory-based experiments to determine their leaching potential. Overall, the sediments were found to contain elevated concentrations of As and Fe with 25 to 400 and 10,000 to 45,000 mg/kg, respectively. Leaching experiments indicated that the pond sediments could potentially release As and Fe with log Kd values ranging from 2.21 to 4.31 L/kg, while Fe ranged from 3.32 to 5.53 L/kg.


2010 ◽  
Vol 162 (1) ◽  
pp. 208-216 ◽  
Author(s):  
K. Samaras ◽  
A. Zouboulis ◽  
T. Karapantsios ◽  
M. Kostoglou

2001 ◽  
Vol 43 (8) ◽  
pp. 9-18 ◽  
Author(s):  
T. Schofield

Dissolved Air Flotation (DAF) has become increasingly important in the field of potable water treatment, as a preferred option for treating upland and stored lowland waters. This paper outlines the development of dissolved air flotation (DAF) in potable water treatment, the benefits and disadvantages and the recent advances that has taken the process technology from an art to a science.


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