This study examines the physicochemical controls on the transport of veterinary pharmaceuticals and hormones from animal manures to surface waters. The researchers investigated the long-term sorption kinetics of the antibiotic lincomycin on various biochars derived from animal manures. They also studied the sorption and transport of the hormone 17β-estradiol on biochars using batch experiments and fixed-bed column experiments. The results showed fast initial surface sorption and slower long-term pore diffusion of lincomycin onto the biochars. Additionally, biochar had a greater sorption capacity for 17β-estradiol than sand and reduced its transport compared to biochar-free sand in column experiments.

1. Physicochemical controls on transport of veterinary pharmaceuticals and hormones to surface waters
Cheng-Hua Liu, Ya-Hui Chuang, Hui Li, Brian J. Teppen, Stephen A. Boyd, and Wei Zhang
Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI
Javier M. Gonzalez, National Soil Erosion Research Lab, USDA-ARS, West Lafayette, IN
Cliff T. Johnston, Department of Agronomy, Purdue University, West Lafayette, IN
Materials and Methods
Results and Discussion
Veterinary pharmaceuticals and hormones in animal
manures are chemicals of emerging concerns (CECs), resulting
in surface water contamination, bacteria antibiotic resistance,
and endocrine disruption in humans and animals. CEC-
contaminated manures are typically applied to agricultural
fields. As CECs tend to sorb strongly to major soil geosorbents,
i.e., clay minerals, amorphous organic matter (AOM), and black
carbon/biochar (BC), top-soils and specifically certain
geosorbent particles become highly enriched in CECs. We
envision that CEC-enriched geosorbent particles mobilized
from top-soils and transported in surface runoff or to shallow
tile-drainage water can contribute a substantial CEC load to
surface waters. We will mechanistically examine CEC sorption
and transport in surface runoff and subsurface flows. We are
investigating a novel management tool, i.e., biochar soil
amendment for enhanced sequestration of CECs in soils,
thereby reducing CEC bioavailability. Knowledge gained will
help improve process-based modeling of CEC transport in
surface runoff and shallow drainage waters. Improved
assessment of CEC fate and transport in soil ecosystems will
contribute to management strategies to mitigate the spread of
CECs in the environment, thus protecting human and
ecosystem health.
Conclusion
 Lincomycin sorption process was characterized by fast and slow
sorption stages.
 The fast sorption within the first two days is primarily contributed
from surface adsorption, and the long-term slow sorption is
controlled by pore diffusion.
 Biochar had a greater sorption capacity for 17β-estradiol than sand.
 Greater transport of 17β-estradiol was observed in the biochar-free
sand than in the biochar-amended sand.
Acknowledgment
This project was supported Agriculture and Food Research
Initiative Competitive Grant No. 2013-67019-21377 from the
USDA National Institute of Food and Agriculture.
Introduction
Long-term sorption kinetics of lincomycin on 17 manure-
derived biochars was investigated by batch sorption
experiments. Sorption of 17β-estradiol on biochars was studied
by both batch sorption experiments and fixed bed column
experiments
Figure 1. Long-term sorption kinetics for 17 manure-derived biochars (initial concentration [C0] = 1000 μg/L,
temperature [T] = 23 °C, pH = 10, ionic strength [IS] = 0.02 M, dosage [D] = 1.0 g/L, particle size [PS] = 75-150 μm,
reaction time = 1 - 360 days)
Biochar Feedstock
BM Bull Manure w/ Sawdust
DM Dairy Manure w/ Rice Hulls
PS Poultry w/ Sawdust
RDM Raw Dairy Manure
CDM Composted Dairy Manure
CDMW
Composted Dairy Manure w/
Wood Waste 1:1
DDM Digested Dairy Manure
WW Wood Waste
ARS Mixed softwood
Short-term
Surface sorption
Long-term
Pore diffusion
lincomycin
Figure 3. Breakthrough curves of 17β-estradiol in the biochar-free
and biochar-mixed sand fixed bed columns (0.1 wt% biochar). (C0 =
10 mg/L, pH = 7.0, IS = 0.01M NaCl, bed depth = 12 cm , flow rate = 2
mL/min , and Darcy velocity = 0.41 cm/min)
Figure 2. Adsorption isotherm of 17β-estradiol on biochar
(ARS450) and quartz sand (Unimin Co.) in the batch experiments.
(C0 = 1 to 10 mg/L, T = 23 °C, pH = 7.0, IS = 0.01M NaCl, D = 10 g/L
for biochar and 100 g/L for sand, PS = 75-150 μm for biochar and
250-500 μm for sand, reaction time = 1 day)
Batch sorption study Fixed-bed column study