Ecotoxicological impacts (survivorship, growth) of two detergents, the linear alkylbenzene sulfonates (LAS) and the nonionic surfactants, nonylphenol ethoxylate (NPE), were examined on two branching coral species (Stylophora pistillata and Pocillopora damicornis). Nubbins assays (n = 1,890, 24-h exposures, 203-day monitoring) revealed high mortality in 1 and 5 mg/l detergents concentrations (for both species combined, LAS LC₅₀ = 1.99 mg/l; NPE LC₅₀ = 2.16 mg/l). Assays further showed detergent as species-specific mortalities (Stylophora LAS LC₅₀ = 1.00 mg/l; NPE = 3.03 mg/l; Pocillopora LAS LC₅₀ = 2.21 mg/l; NPE = 2.26 mg/l), also influenced by genotype-specific mortalities, phenomena which could downgrade genetic diversity of corals in the field, leaving frequently or chronically affected areas with detergent-resistant genotypes. Results revealed that LAS detergents were significantly more detrimental to coral nubbins than NPE detergents, resulting in high mortality and reduced tissue growth on substrates. Surprisingly, nubbins exposed to second and third LAS treatments exhibited significant higher survivorship levels than after the first exposure, whereas in all NPE treatments, nubbins’ survivorship did not significantly differ in the repeated exposures as compared to the first set of assays. This outcome, while adding to our knowledge for the toxicity of various detergents, highlights the need to reduce repeated sewage spills. Furthermore, it is recommended that reef managers should emphasize disparate detergents’ ecotoxicity on corals when establishing environmental policies.

The potential use of the arsenic-tolerant woody leguminous species Anadenanthera peregrina (L) Spegazzini for rehabilitating arsenic (As)-contaminated areas was studied. In an As (539.33 mg/kg)-contaminated soil experiment, plants were able to accumulate arsenic in their roots with a low transfer index to the shoot. Inoculation with arbuscular mycorrhizal fungi (AMF) amplified this behavior and improved both biomass production and the phosphorus concentration in the shoot. AMF inoculation not only improved A. peregrina plant growth but also protected the shoot against As toxicity. Aside from the AMF inoculation, the addition of organic matter reduced the soil pH, thus improving the ability of the roots to accumulate arsenic. The majority (81 %) of the variations in As accumulation in A. peregrina roots were explained by the effects of the organic matter and soil pH as well as AMF treatments, as found by a principal component analysis. A. peregrina promoted phytostabilization through As root sequestration. Therefore, A. peregrina plants inoculated with AMF in the presence of organic matter are recommended to rehabilitate degraded areas of soil contaminated with arsenic.

The outstanding biological performance and non-food utilization of bioenergy grass possibly make it to be the best candidate for phytoremediation of heavy metal-contaminated soil, but evidence is limited. In this study, we conducted pot experiments to quantify the performance of two promising energy grasses, Arundo donax and Miscanthus sacchariflorus, in the phytoremediation of Zn- and Cr-contaminated soil. The results showed that (1) the biomass and root length of the two grasses were firstly increased and then kept stable or slightly decreased with increasing soil Zn/Cr concentration, implying that the two grasses had strong tolerance to Zn/Cr contamination; (2) the Zn/Cr concentration in the grass roots was two to seven times of that in the shoots, while both of them were positively correlated with the Zn/Cr concentration in soil; (3) the total accumulation of Zn/Cr in the grass (shoots + roots) was firstly determined by their concentration in the shoots and secondly determined by the shoots’ biomass, indicating that most of the Zn/Cr could be removed from contaminated soil by harvesting the aboveground parts; (4) the accumulating amount of the two grasses for Zn were 17.5 and 12.1 mg plant⁻¹, respectively; while the accumulating amount for Cr were 3.9 and 2.9 mg plant⁻¹, respectively. Taken together, the two energy grasses had strong tolerance and high accumulating ability for Zn/Cr, and therefore, they are promising candidates for the phytoremediation of Zn-/Cr-contaminated soil.

Poultry feed is often supplemented with low dosages of antibiotic to promote growth, making farms and animal processing facilities potential point sources of antibiotic-resistant fecal bacteria to aquatic ecosystems. In 2010 and 2011, we detected high concentrations of fecal indicator bacteria (FIB) in effluent released from a poultry processing plant into a headwater stream in Greenville, South Carolina. The FIB pollution became undetectable in 2012 with the plant under new management. To determine the plant’s impacts on the stream, we compared the genetic variations of Escherichia coli populations from upstream and downstream of the plant and from reference streams in the same watershed by classifying each isolate into an E. coli reference collection (ECOR) phylogenetic group. For tetracycline-resistant E. coli isolates, we analyzed the resistance genes, minimum inhibitory concentrations (MICs), gene transferability, and plasmid incompatibility groups (Inc). Distributions of ECOR groups upstream and downstream of the plant differed significantly in 2011 but not in 2012. The resistance genes tet(A) and tet(B) were prevalent, with tet(A) more likely to be found on the promiscuous IncP plasmid. A higher percentage of isolates having both tet(A) and tet(B) was found downstream in 2011 than in 2012. Dual-gene isolates did not have higher MICs than single-gene isolates but were more likely to transfer tet(A) on IncP. We propose that the processing plant acted not only as a point source of FIB but also as a factor influencing gene transferability. Additionally, given the results from 2012, the FIB impacts of the processing plant appeared to be reversible.

Normal seed germination of native herbaceous species can be reduced by high concentrations of deicer products and their constituent salts. Chloride salts are commonly used during the winter months in temperate climates to remove ice and snow. Although these products greatly improve driving conditions, they can have detrimental effects on the vegetation growing along highways. The purpose of this laboratory study was to determine the impact of a magnesium-based deicer product and a sodium-based deicer product and the major salts they contain on the germination and viability of several species of grasses and forbs native to Colorado and planted in revegetation seedings there. Seeds were placed on blotter paper saturated with either a water control, one of three concentrations of each of the deicing solutions, or one of three concentrations of a pure NaCl or MgCl₂ solution. Increasing concentrations of salt ions generally resulted in delayed and reduced normal seed germination, especially the sodium- and magnesium-based deicer solutions. Germination for most species was lower when seeds were grown in deicer solution compared with germination percent of seeds grown in the pure salt solutions. Some species were more tolerant of one of the salts and deicers. Species with C4 photosynthetic pathway were more tolerant than C3 species of high concentrations of both deicer products. Those species which attained the highest germination percent under moderate or high solution concentrations included blue grama, buffalograss, little bluestem, mountain brome, and slender wheatgrass.

This study was carried out to evaluate the linkages among herbaceous plant biomass (i.e., aboveground and litter biomasses) and diversity (Shannon-Wiener index) in riparian and non-riparian areas, land use, and lotic water quality (which included first- and second-order natural streams, a canal, and a reach of a lowland river). Herb stands selected were free from anthropogenic disturbances such as farming and construction activities for a period of 3 years (this was the dominant and peak frequency of disturbances of the study area). The results suggested that herb indicators are good representatives of the land use. However, land use explanations for herb indicators were complex and not universal for all lotic waters. The correlations between herb indicators and water quality were strong for the low-order natural streams. In these streams, herb indicators explained >36 % of the total variation with several statistically significant herb indicators. However, the large river section showed weak correlations. Furthermore, the canal’s hydrology (connectivity to sea) seemed to be more influential in shaping its water quality. This study demonstrated that the rehabilitation works with a span of 3–4 years using herbs in riparian and/or non-riparian areas could significantly improve water quality of low-order streams with natural origin.

Biodegradation of different tall oil soaps was studied in order to examine the behaviour of these bioproducts in natural environments and to study their biodegradation rates. The rates of biodegradation were studied by modelling the biodegradation phenomenon as a pseudo-first-order reaction. Biodegradation was studied in seven different environments. Four of these were water phases: groundwater in aerobic and anaerobic conditions, river water and Office of Environmental Compliance and Documentation (OECD) 301 F standard conditions. In addition, three solid phases, sand, acidic forest soil and topsoil, were used as a solid matrix. The results showed that the matrix and the concentration had a strong effect on both the rate and degree of the biodegradation reaction. As a result, all of the tall oil soaps were about 57–85 % biodegradable in OECD 301 F conditions, but only moderately biodegradable in Finnish river water taken in the summer. When compared to the sample taken in the autumn, the biodegradation degree was considerably higher. In groundwater, biodegradation degree was low, even negligible in anaerobic conditions. With ten times less sample content, the biodegradation degrees in groundwater and surface water increased to 60 % for all the tall oil soaps, with one soap, in particular, up to 80 % during 100 days of measurement. In the topsoil, biodegradation was vague, and in slightly acidic forest soil, the decomposition reactions were complex. This is probably due to gas formation in the side reactions. In sand, tall oil soaps did not biodegrade at all.

A total of 179 surface sediment samples from shallow waters have been collected in Catalonia (Northwestern Mediterranean) from 2002 to 2010 to analyze heavy metals (Al, Cd, Cu, Hg, Pb, V, and Zn) concentrations, organic matter content, and sediment size in order (i) to find baseline values, (ii) to investigate metal contamination trends, and (iii) to identify its spatial and temporal distribution. Highest metals concentrations were registered in the Barcelona metropolitan area and in the mouth of Besòs and Llobregat Rivers for Zn, Cu, Pb, and Cd. Mercury was also abundant in these areas but the highest record was found close to Tarragona. The concentrations agree with those reported in other studies performed in big river’s mouths and industrialized areas. The absence of large industrial activity and urbanization outside Barcelona and Tarragona explains the low metal contents found at the other sampling sites. Based on enrichment factor (EF), Pb was the most enriched metal. Results will provide a useful aid for sustainable marine management in Catalonia.

The Lea Navigation in the north-east of London, a canalized reach of the River Lea, is affected by episodes of very low levels of dissolved oxygen. The problem was detected by the Environment Agency from the confluence with Pymmes Brook (which receives the final effluent of Deephams sewage treatment works) to the Olympic site (Marshgate Lane, Stratford). In this study, possible causes and sources of the poor water quality in the Lea Navigation were investigated using algal bioassays and detailed spatial seasonal mapping of the physico-chemical parameters collected in situ. Results showed chronic pollution and identified polar compounds in the river water and high bacterial concentrations as possible causes of low dissolved oxygen levels. This study confirmed the negative impact of Deephams sewage treatment works (via Pymmes Brook) on the water quality of the Lea. However, whilst the Environment Agency had previously focused on the pollution created by the sewage treatment works, results showed evidence of other sources of pollution; in particular, Stonebridge Brook was identified as an uncontrolled source of pollution and untreated wastewater. This study demonstrates the value of conducting combined methodologies and detailed monitoring. Other possible sources include Old Moselle Brook, diffuse pollution from surface run-off, boat discharges and other undetected drainage misconnections.

Biodiesel has proven to be a reasonable substitute to petroleum diesel owing to continuous depletion and pollution caused by the latter. The uncomplicated process of production of fatty acid methyl ester or biodiesel as it is commercially known has made it an even better substitute of fossil diesel. The preparation of biodiesel involves the use of alcohol (methanol) and hydroxides (NaOH). There is a possibility that some of these compounds remain unreacted and needs to be washed with water. This residue water containing alcohol and hydroxide residues if discharged in the soil may affect its quality. This research paper deals with the effect of biodiesel effluent on various physico-chemical properties of soil. The result of the research proves that the biodiesel effluent if discharged in soil will degrade soil quality.