Abstract

Pharmaceutical substances represent a risk for aquatic environments and their potential impacts on the receiving environment are poorly understood. Municipal effluents are important sources of contaminants including common pharmaceuticals like anti-inflammatory and anti-convulsive substances. The removal of pharmaceuticals, particularly those highly soluble can represent a great challenge to conventional wastewater treatment processes. Hydrophilic drugs (<em>e.g.</em> acidic drugs) have properties that can highly influence removal efficiencies of treatment plants. The performance of different wastewater treatment processes for the removal of specific pharmaceutical products that are expected to be poorly removed was investigated. The obtained results were compared to inherent properties of the studied substances. Clofibric acid, carbamazepine, diclofenac, ibuprofen and naproxen were largely found in physicochemical primary-treated effluents at concentrations ranging from 77 to 2384 ng/L. This treatment type showed removal yields lower than 30%. On the other hand, biological treatments with activated sludge under aerobic conditions resulted in much better removal rates (>50% for 5 of the 8 studied substances). Interestingly, this latter type of process showed evidence of selectivity with respect to the size (R2=0.7388), solubility (R2=0.6812), and partitioning (R2=0.9999) of the removed substances; the smallest and least sorbed substances seemed to be removed at better rates, while the persistent carbamazepine (392 ng/L) and diclofenac (66 ng/L) were poorly removed (<10%) after biological treatment. In the case of treatment by aerated lagoons, the most abundant substances were the highly soluble hydroxy-ibuprofen (350-3321 ng/L), followed by naproxen (42-413 n/L) and carbamazepine (254-386 ng/L). In order to assess the impacts of all these contaminants of various properties on the environment and human health, we need to better understand the chemical and physical transformations occurring at the treatment plant and in the receiving waters.

Highlights

  • Pharmaceutical and personal care products (PPCPs) are introduced into the environment via a number of routes, the primary one being the discharge of treated and poorly treated wastewater to surface water.[1]

  • Recent studies have clearly shown that the elimination of PPCPs in municipal sewage treatment plants (STPs) is often incomplete with efficiencies averaging 75%, but in many cases less than 20% depending on the treatment process used, the environmental temperature, light and matrix effects, and substance’s properties as well.[5,6,7]

  • The results of the present study clearly point out quite low removal efficiency of the hydrophilic pharmaceuticals from physicochemical treatments

Read more

Summary

Introduction

Pharmaceutical and personal care products (PPCPs) are introduced into the environment via a number of routes, the primary one being the discharge of treated and poorly treated wastewater to surface water.[1]. Lajeunesse, 2012 Licensee PAGEPress, Italy Journal of Xenobiotics 2012; 2:e3 doi:10.4081/xeno.2012.e3 pollutants removal from raw sewage water is their ability to interact with solid particles, either natural (clay, sediments, microorganisms) or chemical additive mixtures to the medium (e.g., active carbon, coagulants) This action tends to facilitate the removal or biodegradation of pollutants by physicochemical (precipitation, flotation) or biological (activated sludge) processes.[12] as reported by Carballa et al.[13] and Loffler et al.,[14] compounds with low partitioning coefficient (Kd) or low Kow values tend to remain in the aqueous phase, which favor their mobility through the STP and in the receiving environment.

Clofibric acid
Activated sludge
Findings
Conclusions
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call