Journal of Hazardous Materials A136 (2006) 151–163 Trihalomethanes formation potential of shrimp farm effluents Taha F. Marhaba a,∗ , Aweewan Mangmeechai b , Chaichana Chaiwatpongsakorn b , Prasert Pavasant b,c a Department of Civil Environmental Engineering, New Jersey Applied Water Research Center, New Jersey Institute of Technology, University Heights, Newark, NJ 07102-1982, USA b National Research Center for Environmental and Hazardous Waste Management, Chulalongkorn University, Bangkok 10330, Thailand c Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand Received 18 June 2005; received in revised form 2 December 2005; accepted 6 December 2005 Available online 18 January 2006 Abstract Shrimp farm effluents along the Bangpakong River in the Chachoengsao Province of Thailand were evaluated for their trihalomethane formation potential (THMFP) and related parameters. The dissolved organic carbon (DOC), salinity and bromide ion concentrations of shrimp farm effluents were in the ranges of 12–14 mg/L, 0.1–14.5 ppt, and 0–14 mg/L, respectively. The dissolved organic matter was fractionated into hydrophobic and hydrophilic fractions having a range concentration of 3–5 and 8–10mg/L, respectively. The THMFP for all shrimp farm effluents analyzed was in the range of 810–3100 g/L. The hydrophilic organic fraction was found to be a more active precursor of trihalomethanes (THMs) with 700–966 g/L THMFP obtained from this fraction, while only 111–363 g/L THMFP was derived from the hydrophobic fraction. The experimental results showed that salinity and bromide played crucial roles in the formation of THMs. At low salinity and bromide levels, chloroform was the dominant THM species, whereas at high salinity and bromide levels, bromoform became the dominant species. A Fourier Transform Infrared (FTIR) spectrum analysis of the samples before and after chlorination illustrated that the functional groups involved in the THM formation reaction were phenolic compounds, amines, aromatic hydrocarbons, aliphatic bromo-compounds, and aliphatic chloro-compounds. © 2005 Elsevier B.V. All rights reserved. Keywords: THMFP; Shrimp farm wastewater; Hydrophobic; Hydrophilic; Disinfection by-product 1. Introduction Low-salinity shrimp farming is one of the most commonly applied shrimp culture techniques in Thailand [1–3]. Approx- imately, 40% of Thailand’s cultured shrimp production came from 22,455 ha of inland shrimp farms [4,2]. Despite the success of shrimp culture, the unplanned and uncontrolled expansion of shrimp farming into inland-freshwater areas has raised sev- eral environmental issues, such as the contamination of surface and ground water by organic matter and chemicals used in shrimp culturing (a rough estimate of the water consumption of shrimp farms per 1 ha per one crop is 9000–33,000 m 3 /ha, [2,5]). Another hidden problem, but significant in terms of public health, is the increasing risk of having potentially carcinogenic contaminants, such as trihalomethanes (THMs), in the potable ∗ Corresponding author. Tel.: +1 973 642 4599; fax: +1 973 596 5790. E-mail address: Marhaba@adm.njit.edu (T.F. Marhaba). water due to the release of potential THM precursors from shrimp farm effluents into source waters. Past research works indicated that the chlorination of natu- ral water containing organic matters could lead to the forma- tion of harmful disinfection by-products such as THMs [6–9] and haloacetic acids (HAAs) [10–12]. THMs, in particular, are known to have the potential to cause cancer, harmful reproduc- tive effects, and kidney, liver, and mental disorders [13–18]. For this reason, several researchers have investigated the potential of the formation of such compounds. THMs formed during the chlorination process not only quantitatively but also qualitatively depend on the characteristics of the water source, particularly the type of organic/inorganic components. Often natural water sources rich in organic carbon were found to have a higher potential to form THMs [19]. Some specific organic species such as 3,5-dihydroxybenzoic acid, resorcinol, orcinol, and 1,3- dihydroxybenzenes were reported to result in high levels of THMs [20–23]. Inorganic species, such as the bromide ion, were also reported to have a significant effect on the formation of 0304-3894/$ – see front matter © 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.jhazmat.2005.12.011