Estrogenic nonylphenol polyethoxylates (NPnEOs) constitute an important class of nonionic surfactants that find wide use in industrial and domestic cleaning products. These chemicals can undergo partial biotransformation to yield the estrogen mimicking nonylphenol (NP). Our investigations at three Northeast Kansas wastewater treatment plants (WWTPs) found NPnEOs and NP in influent wastewater at levels from nondetectable to more than 200 μg/L. Conventional unit processes at these WWTPs were not completely effective in removal of these organic wastewater contaminants. Low levels (up to 23 μg/L) of NPnEOs and NP were detected in the WWTP effluents that are discharged into the Kansas River. A large portion of NPnEOs and NP appeared to adsorb to the biosolids, a phenomenon that likely prevented their degradation in the bioreactors. As much as 898 mg/kg NP was measured in biosolids from one WWTP. Onsite composting appeared to reduce NP, nonylphenol mono-ethoxylate (NP1EO), and nonylphenol di-ethoxylates (NP2EOs) in the biosolids.

Quantifying the surface color changes by digital image analysis to assess the quality of the sewage sludge brick is investigated. Relationships among the firing temperatures, percent weight of incinerated sludge ash added, and changes to red, green, and blue of the sludge bricks are studied. Indices, deduced from those relationships, while assessing the quality of the sludge brick are evaluated. This research involves testing the specimens of sludge brick under different firing temperatures, using a digital camera to capture images of the tested specimens and uploading them to the personal computer, and applying the “image color intensity analyzer” to the images in order to calculate the intensities of red, green, and blue. Among them, results show that red has the highest intensity, followed by green, then blue in RGB color space. Additionally, for HSI color space, hue (H) decreases, while saturation (S) increases with rising temperatures before 800°C. Thereafter, sudden increases and decreases occur for H and S at 1,000°C, respectively. It is suggested that a firing temperature of 800°C or higher is better in brickmaking.

Endocrine-disrupting compounds (EDCs) have been detected in natural waters globally. Additionally, trace concentrations of pharmaceuticals and personal care products (PPCPs) have also been detected in various waters, primarily as the result of incomplete wastewater treatment. Some PPCPs are known to act as EDCs as they can have impacts on the endocrine systems of animals. The detection of EDCs and PPCPs in source water is of great concern since some of these compounds have known physiological responses at low concentrations. The majority of EDCs and PPCPs are more polar than traditional contaminants, such as polychlorinated biphenyls and organochlorine pesticides, and several have acidic or basic moieties. These properties, coupled with trace quantities, create unique challenges for both removal processes and analytical detection. There are two general approaches for monitoring EDCs and PPCPs in water: (1) direct measurement of target compounds via analytical instrumentation and (2) biological assays. These approaches will be discussed with an emphasis on analytical methods for direct measurements.

The U.S. Environmental Protection Agency (U.S. EPA) has been mandated in the 1996 Food Quality Protection Act and 1996 Safe Drinking Water Act Amendments to develop and implement a screening and testing program for endocrine disruptors. U.S. EPA’s recent regulatory activities are summarized, and predictions are made on how U.S. EPA’s drinking water regulatory framework may change to reflect potential short-term (reproductive and developmental) endpoints. A case study using simulated monitoring data is used to show how drinking water monitoring and compliance time frame may change to address the potential adverse health endpoints.

This review focuses on environmental chemicals that mimic the activity of the endogenous estrogen, 17β-estradiol (E2), and their effects on wildlife, because it is the most studied area of endocrine disruption. The potential human health impact of endocrine disruptors is beyond the scope of this paper and readers should refer to other publications as reported by Crisp et al. in 1998 and Safe in 1995. The concentrations of endocrine disrupting chemicals in effluents from sewage treatment plants (STPs) are summarized and compared. By utilizing in vitro and in vivo assays, environmental estrogens from STPs and other point source pollutants have been shown to induce reproductive abnormalities in fish and wildlife. Though treatment systems of sewage facilities can reduce the amounts of endocrine disrupting chemicals, the removal efficiency can still be improved to further reduce estrogenic effects upon aquatic organisms. Up to date, a lack of comprehensive research impedes the ability to correlate estrogenic chemicals to community- and ecosystem-level effects. Thus, total ecosystem evaluations such as species diversity and impact on keystone species and understudied nonpoint source pollution should be two primary focuses of future research.

Research on the fate and transport of endocrine-disrupting compounds and other organic wastewater compounds released into the environment and their potential presence in drinking water is in its infancy. Studies conducted during the last decade in Lincoln, Nebraska, and Berlin, Germany, indicate that removal of less polar compounds probably can be obtained through bank filtration, ground-water enrichment, and additional drinking-water and wastewater treatment processes. Polar compounds, such as atrazine and some metabolites, occur in drinking water obtained from contaminated surface water or ground water, but at concentrations generally lower than those occurring in wastewater and surface water. The results of the studies also suggest that concentrations of nonpolar estrogenic compounds decrease during drinking-water pretreatment processes such as bank filtration and ground-water enrichment.

In Germany, nine permeable reactive barriers (PRBs) for passive in situ remediation of contaminated groundwater have been erected over the last 3 to 4 years (in Bernau, built 2001; Bitterfeld, 1999; Denkendorf, 2000; Edenkoben, 1998 and 2001; Karlsruhe, 2000; Oberursel, 2002; Reichenbach, 2000; Rheine, 1998; and Tübingen, 1998), all revealing interesting design and engineering features. At the Edenkoben site, one can find what is probably one of today’s largest funnel-and-gate (F&G) systems (approximately 450 m long, equipped with six gates). This paper provides an introduction to German PRB projects, focusing on design and engineering features as well as on some major first outcomes regarding contaminant destruction efficiency and long-term performance, where available. It shows the prevalence of F&G and related systems, which are, predominantly equipped with specially positioned or designed funnels and/or gates (for example, relatively flat gates installed close below ground level, or reactors receiving passively or even actively diverted or lifted groundwater). Different zero valent iron types or activated carbon are the reactive materials exclusively applied in German PRBs to treat chlorinated volatile organic carbons and polycyclic aromatic hydrocarbons (PAHs), though a biological treatment zone to degrade PAHs is planned to be set up at Offenbach, and different alternative innovative materials are currently being tested in a semitechnical scope at Bitterfeld and elsewhere.

Chloro-s-triazines have been implicated as potential endocrine disrupting compounds in humans based on their common mode of action. Chloro-s-triazines include parent compounds such as atrazine, simazine, and cyanazine as well as a suite of their metabolites. As a result, future drinking water regulations in the United States may be based on total chloro-s-triazine concentrations in addition to the existing regulations based on individual parent herbicides. This paper reviews the effectiveness of conventional drinking water treatment processes including powdered activated carbon, granular activated carbon, ozone, biofiltration, and membranes. In general, it is apparent that chloro-s-triazine herbicides and their metabolites should be readily controlled using these conventional technologies.

Understanding the behavior of estrogenic endocrine disrupting compounds (EEDCs) during biological wastewater treatment is a critical aspect of protecting aquatic ecosystems and drinking water supplies. Binding coefficients $\left(K_{\mathrm{coc}}\right)$ of 17β-estradiol (E2), and 17α-ethinylestradiol (EE2) to colloidal organic carbon (COC) derived from several biological wastewater unit processes was quantified by fluorescence quenching. The magnitude of $K_{\mathrm{coc}}$ for E2 and EE2 was independent of the sorbate’s hydrophobicity $\left(K_{\mathrm{ow}}\right)\text{,}$ but was strongly correlated to the molar extinction coefficient at 280 nm $\left(e_{280}\right)\text{.}$ This suggests that the interactions between the π-electrons of E2 and EE2 and the COC are important in determining binding behavior. The $e_{280}$ coefficients are related to the aerobic sludge age and colloid capture efficiency of the wastewater treatment process. Treatment processes that utilize a physical barrier for liquid-solid separation, such as membrane bioreactors, appear to offer some important advantages in reducing effluent E2 and EE2 concentrations. These results indicate that the colloid phase plays an important role in E2 and EE2 behavior during biological wastewater treatment and colloid transport of these, and possibly other estrogenic compounds, should be considered in any water reuse scenario or environmental modeling application.