First desalination plant in Cyprus — product water aggresivity and corrosion control

doi:10.1016/S0011-9164(01)00271-5

Desalination

Volume 138, Issues 1–3, 20 September 2001, Pages 251-258

https://doi.org/10.1016/S0011-9164(01)00271-5 Get rights and content

Abstract

The first major desalination plant in Cyprus is the Dhekelia Desalination Plant, which utilises the reverse osmosis system. The Dhekelia Desalination Plant started its operation on 1st April 1997, with a capacity of 20,000m³/d, and by the 18th May 1998 its capacity increased to 40,000m³/d. The plant supplies potable water to the Famagusta, Larnaca and Nicosia Districts. During the summer of 1998 there was a change in the colour of the desalinated water 20–30 km far from the plant, where the water appeared to be yellowish-brown, especially in areas where the distribution systems consisted of metal/iron pipelines. The tests results of water samples from the affected areas (Famagusta Area, whose water supply was solely from the Dhekelia Desalination Plant), undertaken from the State General Laboratory and Khirokitia WDD's Laboratory, showed high iron content in the water and the Langelier index was found negative. In order to solve the problem, it was agreed to change the range of pH from 7.0–8.0 to 6.5–9.5. The pH of the desalinated water was then increased by readjusting lime and carbon dioxide dosages. Trials to increase calcium hardness and alkalinity more caused high turbidity in water (3–4NTU). By the increase of pH to values more than 8.5 the Langelier index increased to 0.0–0.5 and the iron content decreased. Later, from September 1999 for the further increase of the hardness of the desalinated water, magnesium sulphate is added at the post-treatment stage in addition to the lime and carbon dioxide. Additional tests have been carried out by installing mild steel corrosion-coupons to the desalinated water from the Dhekelia Desalination Plant as well as at the drinking water reservoirs of different communities in order to examine the corrosive tendency of desalinated water.

References (10)

Contract No 39/94/41, Dhekelia Desalination Plant, Technical Part, Water Development Department, Nicosia, May...
Degremont
Water Treatment Services
(1998)
J.C. Schippers
Course on Desalination
(17–21 April 2000)
K.V. Mayenkar
Quick way to determine scaling or corrosive tendencies of water
(May 30, 1983)

There are more references available in the full text version of this article.

Cited by (55)

Batch and continuous bleaching regimen in the cooling tower of Montazer Ghaem power plant
2023, Journal of Hazardous Materials Advances
In order to control the microbial growth in the cooling tower of thermal power plant, oxidative and non-oxidative biocides are applied in the power industry. Oxidative biocides including chlorine dioxide and bromine-based compounds are effective for controlling microbial growth in cooling towers. The choice of biocide depends on the type of cooling tower, water quality, and regulatory requirements. In the most cases, the bleaching regimen is selected as the most effective and low-cost oxidative biocides in cooling tower. The bleaching regimen is carried out in batch mode generally and herein for the first time, the continuous bleach is examined in the cooling tower of Montazer Ghaem power plant by evaluating the microbial growth. In the batch mode, 0.25 m³ of 12% bleach is injected into 1600 m³ every 3 days and in the continuous mode, the same amount (0.0035 m³/h) is continuously injected. The TBC¹ in the cooling water before bleach, after batch and continuous bleach are 10⁶, 10⁴ and 10³ cfu/mL, respectively. In fact, the performance of the continuous bleach is 10 times more efficient than the batch bleach. The physicochemical parameters including conductivity, NaCl%, TDS, pH, anions and cations concentration are not changed significantly and the chemical conditions are stable in both regimes which is proved that changing the bleach injection does not require the different chemical control. The free chlorine concentration in the continuous mode is constant (0.05 ppm) which is controlled the microbial growth and avoided the copper and iron corrosion.
Unexpected failure of cast superduplex stainless steel exposed to high chlorides containing water: From failure analysis to corrosion mechanisms settlement
2022, Engineering Failure Analysis
Citation Excerpt :
Table 1 shows the water chemical composition with very high chlorides content (130 mg/l) and a pH around 6. The pH is usually lowered by the use of some strong organic acids in order to reduce the scale formation, that can be produced due to the high amount of TDS (Total Dissolved Solids) [32–35]. The maximum content of H2S and CO2 is given in table 1.
This work deals with the failure analysis of a super duplex valve operating in technical waters with high chlorides content up to 80 °C. A careful fracture surfaces and microstructural characterization was combined with corrosion studies (SKPFM (Scanning Kelvin Probe Force Measurements) and polarization curves) of different valve regions in order to determine the failure mechanism.
It was found that the cast material presents a segregated microstructure containing ferritic phases with different PREN (Pitting Resistance Equivalent Number). This strongly affects the corrosion properties of the material, enhancing the susceptibility to localized corrosion and leading to SCC (Stress Corrosion Cracking) failure.
Remineralization of desalinated water: Methods and environmental impact
2020, Desalination
Desalinated water is not suitable for direct use as it is prone to corrosion and has adverse effects on human health and the environment. Desalinated water is slightly acidic, lacks minerals and cannot be used un-buffered, thus making remineralization an important component downstream of desalination. We systematically review remineralization requirements and regulations with respect to corrosion control, human health and agriculture needs. This includes not only concentrations of specific ions, but also relative ratios. We compare and contrast existing remineralization methods with emerging, energy-efficient methods that require less chemicals. The impact of the lack of certain minerals such as magnesium, calcium and sulfate, on health and environment are evaluated in order to guide regulatory bodies towards maintaining safe standards. Emerging methods include harvesting minerals from seawater or brine through the combination of nanofiltration membranes with others (CIX, UF, Diananofiltration) and using them to re-mineralize the product stream. This reduces the need for chemicals from an external source and thus lowers the environmental impact. This review is to be used as a tool for guiding readers in proper remineralization choices depending on their application.
Cartridge filter selection and replacement: Optimization of produced water quantity, quality, and cost
2020, Desalination
In this study at a full-scale desalination installation seven types of commercially available cartridge filter (CF) elements were evaluated in terms of: (i) water production volume (m³), (ii) produced water quality, and (iii) operational cost (€cent/m³). The cost of optimal CF replacement time relative to increased CF pressure drop was determined for three electricity tariffs (0.05, 0.15, and 0.25 €/kWh) to assess further cost reduction. CF 1 was able to achieve the highest water production rate, the lowest produced water SDI, and the lowest cost of operation. The total costs of cartridge filtration varied between 1.22 and 1.70 €cents/m³ produced water, depending on the CF type. Replacing the worst-performing CF type by the best-performing CF type would reduce operational CF costs by about 39.3%, enabling a cost saving of 0.48 €cents/m³ produced water, emphasizing that selection of the right CF enables a large reduction of cartridge filtration costs. Moreover, depending on the electricity tariff an additional 2–16% cost reduction can be achieved by replacing CFs at an optimal time. At high energy cost, it may be more economical to replace cartridge elements more often to reduce the increased cost associated with the required higher pressure.
Corrosion of stainless steel valves in a reverse osmosis system: Analysis of corrosion products and metal loss
2019, Engineering Failure Analysis
Citation Excerpt :
However, highly purified reclaimed water may raise the risk of corrosion of equipment and distribution systems. This is because the chemical stability indices of the water (e.g., Larson Index) may fall within the unstable range [23,24]. Stainless steel is a group of iron-chromium (FeCr) alloys used as corrosion resistant material in various industries [25,26].
Aggressive aqueous environments in reclaimed water treatment plants can cause corrosion of stainless steel equipment, which may further result in equipment failure. The current study carried out morphological, micro-structural, mineralogical and chemical analyses to understand the differences between corrosion products formed on stainless steel valves at different locations in a reclaimed water plant reverse osmosis system. Correlation between formation of corrosion products and metal loss was studied in depth. For that purpose, a new parameter, namely metal loss percentage (MLP), was introduced to evaluate the extent of metal loss on the surfaces of stainless steel valves. The results showed that the valves had corroded to various extents. The corrosion included pitting, cracking and accumulation of products on the alloy surface. The corrosion products were composed of iron oxides, iron hydroxides, chromium oxide, calcium carbon oxide, siderite and green rust. There was a significant positive correlation between the weight percentage increase in the corresponding elements in these products and MLP on the alloy surface. O and C were among the elements most correlated with metal loss on the alloy surface. The latter correlated linearly with MLP. Based on these results, the reaction pathways for the formation of corrosion products on the surfaces of valves were postulated.
Post-Treatment of Desalinated Water-Chemistry, Design, Engineering, and Implementation
2018, Sustainable Desalination Handbook: Plant Selection, Design and Implementation
The quality with which water is released from desalination plants increases continuously. However, prior to the post-treatment step, desalination permeates are slightly acidic, contain very low buffering capacity, and are very soft. As such, the water may be aggressive and corrosive to infrastructure, resulting in adverse health and economic effects. Consequently, a post-treatment step in which the chemical stability, buffering capacity and mineral content of the water is adjusted, is invariably practiced. This chapter reviews the knowledge accumulated in the last decades on desalination post-treatment processes. It covers fundamental chemistry aspects related to the aqueous, gaseous and solid phases relevant to post-treatment processes. The chapter also provides a thorough explanation on required water quality criteria; the advantages and disadvantages of currently applied post-treatment processes are detailed, engineering and cost considerations are discussed, state of the art post-treatment alternatives are covered, and contemporary research trends are listed.

View all citing articles on Scopus

^☆: Presented at the European Conference on Desalination and the Environment: Water Shortage, Lemesos, Cyprus, 28–31 May 2001.

View full text

First desalination plant in Cyprus — product water aggresivity and corrosion control☆

Abstract

Degremont

Water Treatment Services

Course on Desalination

Quick way to determine scaling or corrosive tendencies of water