A review on emerging contaminants in wastewaters and the environment: Current knowledge, understudied areas and recommendations for future monitoring

Abstract

This review identifies understudied areas of emerging contaminant (EC) research in wastewaters and the environment, and recommends direction for future monitoring. Non-regulated trace organic ECs including pharmaceuticals, illicit drugs and personal care products are focused on due to ongoing policy initiatives and the expectant broadening of environmental legislation. These ECs are ubiquitous in the aquatic environment, mainly derived from the discharge of municipal wastewater effluents. Their presence is of concern due to the possible ecological impact (e.g., endocrine disruption) to biota within the environment. To better understand their fate in wastewaters and in the environment, a standardised approach to sampling is needed. This ensures representative data is attained and facilitates a better understanding of spatial and temporal trends of EC occurrence. During wastewater treatment, there is a lack of suspended particulate matter analysis due to further preparation requirements and a lack of good analytical approaches. This results in the under-reporting of several ECs entering wastewater treatment works (WwTWs) and the aquatic environment. Also, sludge can act as a concentrating medium for some chemicals during wastewater treatment. The majority of treated sludge is applied directly to agricultural land without analysis for ECs. As a result there is a paucity of information on the fate of ECs in soils and consequently, there has been no driver to investigate the toxicity to exposed terrestrial organisms. Therefore a more holistic approach to environmental monitoring is required, such that the fate and impact of ECs in all exposed environmental compartments are studied. The traditional analytical approach of applying targeted screening with low resolution mass spectrometry (e.g., triple quadrupoles) results in numerous chemicals such as transformation products going undetected. These can exhibit similar toxicity to the parent EC, demonstrating the necessity of using an integrated analytical approach which compliments targeted and non-targeted screening with biological assays to measure ecological impact. With respect to current toxicity testing protocols, failure to consider the enantiomeric distribution of chiral compounds found in the environment, and the possible toxicological differences between enantiomers is concerning. Such information is essential for the development of more accurate environmental risk assessment.

Characterization of Composted Organic Amendments for Agricultural Use

“…Unfortunately, there are no legal limits for organic and emerging (compounds previously unknown or undetected; the term includes a large variety of products such as pharmaceuticals, veterinary products, pesticides, nanomaterials, etc.) contaminants (Petrie et al, 2015). In this respect, highest abundance values for the intl1 gene, related to class 1 integrons, were found in compost in pellet form and bokashi.…”

Sources of endocrine-disrupting compounds and their migration to the environment

“…BPA can also partially accumulate by passing through soil and river sediments. [15] 60-600 [43] 360-1620 [18] 378-890 [9] 416-2050 [23] 1800 [40] 2-44 [43] 30-1100 [15] 35-86 [23] 110-300 [18] 700 [40] 1.2-1900 [1] 2.1-87 [13] 2.2-4230 [21] 6-34 [23] 6-68 [11] 6-500 [26] 6-881 [22] 7.5-334 [12] 55-162 [27] 192-215 [15] 460-4800 [25] b.l.q.-494 [17] b.l.q.-7000 [19] b.l.q.-9300 [28] 1-1136 [20] 1-11 [4] 79-2550 [15] 600-11000 [14] 0.17-1.25 [2] 0.58-36700 [8] 1.1-43 [42] 4.3-130 [25] 10-530 [23] 53-196 [43] 0.32 [6] Fu and Kawamura [5] showed that bisphenol A is also present in air samples. In the agricultural areas of China, its concentration in the air does not exceed 240 pg/m3, but the air samples in urban areas are more contaminated (20-2.340 pg/m 3 ).…”

Study of the degradation performance (TOC, BOD, and toxicity) of bisphenol A by the photo-Fenton process

“…CECs have received increasing attention during the last decades, and ways to remove them from the wastewater have been intensively researched (Petrie et al 2015 ).…”

“…Petrie et al ( 2015 ) claimed that further studies, which combined the use of chemical and biochemical analysis to better assess the environmental risk, are required. Accordingly, the main purpose of this work was to determine appropriate photo-Fenton process variables for an efficient BPA mineralization performance, biodegradability increase, and toxicity removal.…”