The increasing demand for fresh water has forced many countries to use reclaimed wastewater for agricultural purposes. This water contains pharmaceuticals and personal care products (PPCPs) that remain biologically active following passage through wastewater treatment plants. Run-off from farms and contaminated water from treatment facilities exposes aquatic ecosystems to PPCPs. This study examined the effects of PPCPs on a lower trophic organism. Culex quinquefasciatus larvae were reared in water contaminated with environmentally relevant concentrations of common PPCPs. Acetaminophen alone and a mixture of contaminants were found to increase developmental time of larvae. Susceptibility to Bti increased in larvae exposed to antibiotics, acetaminophen, or a mixture of PPCPs. Antibiotics, hormones, and the mixture altered the mosquito bacterial microbiome. Overall, the results indicate that at environmentally relevant concentrations, PPCPs in reclaimed water can have biologically important effects on an ecologically and medically important lower trophic level insect.

The use of shellfish aquaculture for nutrient removal and reduction of coastal eutrophication has been proposed. Published literature has indicated that nitrogen contained in harvested shellfish can be accurately estimated from shell length:nitrogen content ratios. The range of nitrogen that could be removed by a typical farm in a specific estuarine or coastal setting is also of interest to regulators and planners. Farm Aquaculture Resource Management (FARM) model outputs of nitrogen removal at the shellfish farm scale have been summarized here, from 14 locations in 9 countries across 4 continents. Modeled nitrogen removal ranged from 105lbsacre−1year−1 (12gm−2year−1) to 1356lbsacre−1year−1 (152gm−2year−1). Mean nitrogen removal was 520lbsacre−1year−1 (58gm−2year−1). These model results are site-specific in nature, but compare favorably to reported nitrogen removal effectiveness of agricultural best management practices and stormwater control measures.

Biological and geochemical variables in the water column and sediments were monitored along a transect of a mussel farm located in a transitional environment in Maliakos Gulf, a semi-enclosed gulf in eastern Mediterranean. Analyses of water, sediment and macrofauna samples were used to calculate ecological status indicators in the context of the European Water Framework Directive. The water column ecological status was “Poor” or “Bad” showing little change with distance from the farm, but the ecological status of the benthic communities was found to be “Good,” although there were quantitative changes in macrofaunal indices with distance from the farm.

Shellfish aquaculture is a widely practiced way of producing food for human consumption in coastal areas. When farming intertidal clams, farmers commonly protect young seedling clams from predatory losses by covering farmed plots with netting or screening. Recent discussion of the effectiveness of protective nets or screens and their environmental effects has raised questions concerning the utility of the practice. We provide data based on a review of more than 35 peer-reviewed articles, as well as our own research that demonstrates the efficacy of predator protection for clam farms in various habitats around the world. In addition, we evaluate the effects of screening on temperature, and comment on ancient practices of clam gardening as conducted in the Pacific Northwest.

In New Caledonia, semi-intensive shrimp farms release untreated effluents into the mangrove. Foraminiferal assemblages were analyzed for assessing the impact of effluent release on the benthic compartment. Comparison was made between samples collected (1) in an effluent receiving mangrove before and after the rearing cycle, and (2) for one-year monitoring an effluent receiving and a control mangrove. The distribution of foraminiferal assemblages was primarily driven by the gradient between Rhizophora stands and salt-flats, related to salinity and tidal elevation, and by seasonal cycles. The potential impact of effluent release was due to the combined effects of normal-saline effluents on surface salinity, and of nutrient input and microbial stimulation on food availability. Foraminiferal assemblages did not indicate a substantial impact of farm effluents and suggest that semi-intensive shrimp farming using mangrove for effluent discharge may appear as a sustainable solution in New Caledonia, when considering only the impact on the mangrove itself.

After alkaline hydrothermal conversion of volcanic tephra to zeolite (VT-Z) particles, calcium ion cross-linked alginate-zeolite composites (VT-Z/CA) were subsequently fabricated as sorbents for enhancing removal of Cu(II) ions from aqueous solution. The naturally occurring VT minerals were used as silica and alumina sources for zeolite crystallization. The conversion conditions were optimized by altering the alkaline concentration, conversion time, temperature and addition of ethanol. After the synthesized VT-Z particles were entrapped into CA biopolymer template, the developed VT-Z/CA composites not only make full use of the excellent adsorption capabilities of zeolites but also prevent the major problems of mobility/agglomeration for zeolite particles in aqueous media. The VT-Z/CA composites were characterized and studied for aqueous removal of Cu(II) ions in a batch mode. Solution pH 5.5 was found to be the best choice. The kinetic data were evaluated by the pseudo-first, pseudo-second order, and Elovich model. The adsorption kinetics followed the pseudo-first model. Langmuir isotherm best described the adsorption behavior with the maximum adsorption capacity for Cu(II) at 121.1 mg g⁻¹ (45 °C). The composites were successfully explored for treatment of Cu(II)-bearing livestock farm wastewater in China. The VT-Z/CA composites offer a highly attractive alternative for remediating heavy metal contaminated water with advantages of being easy to operate, cost-effective, biodegradable, and environmentally benign.

Bacterial antibiotic resistance has long been a public health concern worldwide. Although antibiotic abuse highly correlates with occurrence of resistant pathogens in hot spots like animal feedlots, it remains obscure how frequently these resistance genotypes would emerge and/or retain in natural circumstances. In this study, we monitored seven antibiotic resistance genes in various surface waters. All seven resistance genes were detectable in Puzih River samples, including strA (40.6 %), cmlA (29.7 %), blaTEM (9.1 %), tet(B) (8.5 %), sul1 (7.9 %), mecA (3.6 %), and tet(A) (2.4 %). Among these genes, strA was observed in four out of five sampling occasions during the 1.5-year monitoring period and most of the genes were detected at least two times over five samplings. These results imply that surface waters in Taiwan act as potential reservoirs for several resistance genotypes. Moreover, high prevalence of tet(A) (92.0 %) and sul1 (96.0 %) in swine farm wastewater samples suggests routine antibiotic usage and particularly, the fodder supplements could indeed be a risk factor to antibiotic resistance in environments. sul1, tet(A), blaTEM, and strA were detectable in domestic water treatment plants and reservoirs, suggesting that several resistance genotypes against antibiotics as streptomycin, ampicillin, tetracycline, and sulfonamides are likely to persist in natural circumstance and may consequently contaminate the drinking water systems.

At livestock farms, the most important thing is to control odors released from manure. In this study, four commercially available microbial additives designed to control odor and NH₃emissions were applied to swine slurries stored in containers, and their effectiveness in odor reduction was statistically evaluated. Seventeen different odorous compounds in the headspace of each container were analyzed to calculate an overall odor index for slurries treated with different microbial additives over time. Of the four microbial additives tested in this study, only two were effective in reducing the odors from the swine slurry. After a 80-day storage period, the odor indexes of the slurries could be reduced by over 70 % with 50 % reduction in volatile fatty acids. In addition, a significant five orders of magnitude reduction in Escherichia coli could be achieved within 60 days. The other two microbial additives did not affect the odor characteristics of swine slurries under storage; their time profiles were statistically identical with that of the control. Results of this study imply that farmers considering applying microbial additives for controlling odors from swine manure should be careful in choosing an additive.

Pig farms have achieved importance in the last few decades from the perspective of environment protection as a consequence of the intensive rearing systems in livestock production. Ammonia (NH₃) and greenhouse gases (GHG), such as methane (CH₄), carbon dioxide (CO₂), and nitrous oxide (N₂O), are emitted from slurry storage at farm prior to land application, but little is known about these losses under on-farm conditions in Spain. This study assessed the influence of management and environmental parameters on NH₃ and GHG emissions from slurry storage in spring and autumn. Gas emissions were measured in a commercial pig-fattening farm from two lagoons (1000 and 768 m³ capacity, respectively) during 30 days by the floating dynamic chamber system in spring and autumn 2011 (average temperature 19 and 9 °C, respectively). Low NH₃ and CH₄ emissions were registered in spring (range 10–406 and 3–17 mg m⁻² min⁻¹, respectively) probably as a result of low pH values of stored slurry (6.5 to 7.0) and rainfall. High variability on NH₃, CH₄, and CO₂ emissions was observed as a result of differences in temperature and rainfall. No NH₃ emission and low CH₄ and CO₂ emissions were observed in autumn (average 1.2 ± 0.9 and 27 ± 22 mg m⁻² min⁻¹, respectively). Slurry loading operations increased NH₃ losses from storage.

Poultry litter and bedding materials generated from laying chicken farm often contain high levels of arsenic when roxarsone is included in feed to combat disease and improve egg production. This study was conducted to determine the fate and ecological risk of arsenic species in poultry litter which applied to agricultural field. Three poultry litter application rates (0, 10, 60 % dry weight) were used to amend soil samples under anaerobic and aerobic circumstances, respectively, incubated at 30 % moisture content for 110 days. Experiment indicated that under anaerobic circumstance, As(V) and As(III) decreased in treatments applied 60 and 10 % rates within initial 7 days, subsequently methylated arsenic displayed increasing, suggesting biotic activity transformed inorganoarsenical to methylated arsenic species. In contrast, As(V) dropped in the first 7 days but increased thereafter under aerobic circumstances, with methylated arsenic increasing, implying abiotc and biotic activities enhanced arsenic speciation. Based on different arsenic species, we evaluated their ecological risk in poultry litter respectively. It was found that ecological risks under anaerobic circumstance were higher than under aerobic circumstance of the same poultry litter rates, and higher poultry litter rates applied to soil would bring about higher ecological risk. We suggest that poultry litter should be disposed at low rate (approximately 10 %) and applied to soil surface to create aerobic circumstance for the initial 2 months time, but should be buried into a deeper depth thereafter.