scholarly journals A triple bottom line approach to optimising odour removal from a residential water supply

2021 ◽  
Author(s):  
Tara Callingham ◽  
Daniel Ooi ◽  
Linhua Fan ◽  
Felicity Roddick

Abstract Feedwater to Euroa Water Treatment Plant contains increasingly high levels of natural organic matter (NOM) which were determined to cause its strong earthy odour. A multidisciplinary approach was used to evaluate the coagulation process to better remove the taste and odour (T&O) causing organics from water supplied to the local towns. Such high levels of NOM require elevated doses of coagulant for removal, accounting for approximately 60% of the chemical costs. A need arose to reduce these operational costs. However, community expectations regarding T&O, and social and environmental impacts, are not typically considered in this process. The local water corporation, Goulburn Valley Water, undertook a case study involving a comparison of three coagulants to optimise the chemical coagulation process from a multidisciplinary (triple bottom line, TBL) perspective. The financial assessment incorporated operational costs and potential infrastructure requirements. The social assessment investigated the overall impacts on staff operating the water treatment plant and their broader community involvement. The environmental assessment focused on the impact on downstream infrastructure from changes in sludge volumes and wastewater quality, and third-party greenhouse gas emissions from chemical deliveries. From a TBL viewpoint, aluminium chlorohydrate was the most beneficial option.

Vestnik IGEU ◽  
2021 ◽  
pp. 5-12
Author(s):  
E.A. Karpychev

Operational test of the preliminary water cleaning systems is the first and most critical stage when putting into pilot operation a water treatment plant at a thermal power plant (TPP). We have sufficient experience of equipment setting up and operating when most traditional devices of preliminary water purification are used. Also, the main stages and features of the work carried out are known, and a sufficient amount of methodological literature has been published, compared to employment of modern and promising devices. These devices include Actiflo clarifiers. The main feature of the Actiflo technology is introduction of microsand into the stream of treated water. It forms the so-called “centers” of coagulation and is used to make wastewater sludge heavier. The development of a methodology to assess the impact of the actual dose of microsand on the water clarification process will contribute to the solution of the priority task of adapting the promising Actiflo technology for water treatment systems of TPPs. In laboratory studies, the method of pilot coagulation has been used. It allows us to assess the efficiency of coagulation process using generally accepted methods of quantitative analysis of indicators of natural water quality. In subsequent industrial tests, along with the quantitative analysis of water, the actual value of the microsand dose has been assessed using measurements of the proportions of separate fractions in the formed sand-sludge pulp. The results of laboratory and industrial studies of “cold” coagulation process of the Kama River water using Actiflo clarifiers have been obtained. The dependence of efficiency effect of water clarification on the dose of coagulant and the dose of microsand has been determined. To check and maintain the operating mode of the clarifier, a method to assess the actual values of the microsand dose has been developed and proposed. The research results are applicable for low-turbidity colored surface water sources. The results of operating tests of Actiflo clarifiers can be used as practical examples for coagulating water in devices similar in design, for example, VTI-M clarifiers. The proposed method to assess the actual dose of microsand can be used as a technological parameter during the development of the parameter tables when Actiflo clarifiers are used.


1992 ◽  
Vol 26 (5-6) ◽  
pp. 1255-1264
Author(s):  
K. L. Martins

During treatment of groundwater, radon is often coincidentally removed by processes typically used to remove volatile organic compounds (VOCs)-for example, processes such as liquid-phase granular activated carbon (LGAC) adsorption and air stripping with vapor-phase carbon (VGAC). The removal of radon from drinking water is a positive benefit for the water user; however, the accumulation of radon on activated carbon may cause radiologic hazards for the water treatment plant operators and the spent carbon may be considered a low-level radioactive waste. To date, most literature on radon removal by water treatment processes was based on bench- or residential-scale systems. This paper addresses the impact of radon on municipal and industrial-scale applications. Available data have been used todevelop graphical methods of estimating the radioactivity exposure rates to facility operators and determine the fate of spent carbon. This paper will allow the reader to determine the potential for impact of radon on the system design and operation as follows.Estimate the percent removal of radon from water by LGAC adsorbers and packed tower air strippers. Also, a method to estimate the percent removal of radon by VGAC used for air stripper off-gas will be provided.Estimate if your local radon levels are such that the safety guidelines, suggested by USEPA (United States Environmental Protection Agency), of 25 mR/yr (0.1 mR/day) for radioactivity exposure may or may not be exceeded.Estimate the disposal requirements of the waste carbon for LGAC systems and VGAC for air stripper “Off-Gas” systems. Options for dealing with high radon levels are presented.


1996 ◽  
Vol 68 (7) ◽  
pp. 1179-1186 ◽  
Author(s):  
Stephen D. J. Booth ◽  
Daniel Urfer ◽  
Gerard Pereira ◽  
Karl J. Caber

2015 ◽  
Vol 46 (4) ◽  
pp. 291-335 ◽  
Author(s):  
M. Pivokonsky ◽  
J. Naceradska ◽  
I. Kopecka ◽  
M. Baresova ◽  
B. Jefferson ◽  
...  

2006 ◽  
Vol 6 (6) ◽  
pp. 89-98 ◽  
Author(s):  
C.B. Yang ◽  
Y.L. Cheng ◽  
J.C. Liu ◽  
D.J. Lee

A case study on the treatment and reuse of backwash water from Chang-Hsing Water Treatment Plant (CHWTP) and Swan-Sea Water Treatment Plant (SSWTP) of Taipei Water Department was conducted. Both backwash waters showed different properties. However, the characteristics of each backwash water did not vary considerably among samples taken during different time. Results from jar tests indicated that both polyaluminium chloride (PACl) and alum could result in effective removal of turbidity. Both DOC and absorbance of UV254 decreased slightly with increasing coagulant dosage. In continuous operation of backwash water recycle in pilot study in CHWTP, it was found that treated water quality was not affected by two different modes of recycle: intermittent recycle at ratio of 1:7 (backwash water:raw water) and continuous recycle at ratio of 1:42. In the pilot study in SSWTP, no impact was found on the introduction of backwash water at recycle ratio of 4, 6 and 8%, regardless of whether the backwash water was recycled directly or went through 3 min pre-sedimentation before it is recycled. Further study on the impact of typhoon on treatment and recycle of backwash water was recommended.


2019 ◽  
Vol 69 (1) ◽  
pp. 28-38 ◽  
Author(s):  
Atefeh Kaji ◽  
Masoud Taheriyoun ◽  
Amir Taebi ◽  
Mohammad Nazari-Sharabian

Abstract This study aims to assess the efficiency of two natural-based coagulants, namely calcium lactate and tannic acid, and compare them with conventional coagulants, including polyaluminium chloride (PACl) and ferric chloride. Jar test experiments were performed on the raw inlet water of the Isfahan water treatment plant (IWTP) in Iran. Response surface methodology was implemented to design and optimize the experiments. The factors considered in the design were coagulant dose, pH, initial turbidity, and temperature. Results showed the acceptable efficiency of natural coagulants in turbidity reduction, so that they meet the potable standard levels. The final water turbidity in the optimum condition for calcium lactate, tannic acid, PACl, and ferric chloride were 0.58, 0.63, 0.56, and 0.76 NTU, respectively. The comparison between the performances of the coagulants showed no significant difference in turbidity removal. However, the sludge volume produced as well as the impact on pH alteration after coagulation–flocculation were lower when using natural coagulants than with conventional coagulants. Also, the residual aluminum for PACl measured was higher than the desired limit according to Iran's drinking water standard. Finally, the simple additive weighting method was used to rank the four coagulants based on the selected criteria. The results showed that the natural coagulants could be preferable to the conventional coagulants if the concerns regarding disinfection by-product formation due to their residual organics were resolved. Since this issue was fixed in the IWTP due to the ozonation process, calcium lactate was proposed as an efficient alternative to PACl.


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