Coal production negatively affects the environment by the emission of polycyclic aromatic hydrocarbons (PAHs). Two soils (KOK and KB) from a coking plant area was investigated and their total PAH concentration was 40 and 17 mg/kg for the sum (∑) 16 US EPA PAHs, respectively. A third soil was sampled from a bitumen plant area and was characterized by 9 mg/kg ∑16 US EPA PAHs. To reduce the freely dissolved concentration (Cfᵣₑₑ) of the PAHs in the soil pore water, active carbon (AC) and two biochars pyrolysed from wheat straw (biochar-S) and willow (biochar-W) were added to the soils at 0.5–5 % (w/w), each. The AC performed best and reduced the Cfᵣₑₑ by 51–98 % already at the lowest dose. The biochars needed doses up to 2.5 % to significantly reduce the Cfᵣₑₑ by 44–86 % in the biochar-S and by 37–68 % in the biochar-W amended soils. The high black carbon (BC) content of up to 2.3 % in the Silesian soils competed with the sorption sites of the carbon amendments and the performance of the remediation was a consequence of the contaminant’s source and the distribution between the BC and the AC/biochars. In contrast, the carbon amendment could best reduce the Cfᵣₑₑ in the Lublin soil where the BC content was normal (0.05 %). It is therefore crucial to know the contaminant’s source and history of a sample/site to choose the appropriate carbon amendment not only for remediation success but also for economic reasons.

In situ sediment remediation using Ca(NO₃)₂ or CaO₂ for odor mitigation and acid volatile sulfide (AVS) and organic pollutant (such as TPH and PAHs) removal was reported in many studies and fieldwork. Yet, the associated effects on metal mobilization and potential distortion in bioavailability were not well documented. In this study, contaminated river sediment was treated by Ca(NO₃)₂ and CaO₂ in bench studies. Through the investigation of AVS removal, organic matter removal, the changes in sediment oxidation-reduction potential (ORP), microbial activity, and other indigenous parameters, the effects on metal bioavailability, bioaccessibility, and fraction redistribution in sediment were evaluated. The major mechanisms for sediment treated by Ca(NO₃)₂ and CaO₂ are biostimulation with indigenous denitrifying bacteria and chemical oxidation, respectively. After applying Ca(NO₃)₂ and CaO₂, the decreases of metal concentrations in the treated sediment were insignificant within a 35-day incubation period. However, the [SEMₜₒₜ-AVS]/f OC increased near to the effective boundary of toxicity (100 μmol g⁻¹ organic carbon (OC)), indicating that both bioavailability and bioaccessibility of metals (Cu, Zn, and Ni) to benthic organisms are enhanced after remediation. Metals were found redistributed from relatively stable fractions (oxidizable and residual fractions) to weakly bound fractions (exchangeable and reducible fractions), and the results are in line with the enhanced metal bioavailability. Compared with Ca(NO₃)₂, CaO₂ led to higher enhancement in metal bioavailability and bioaccessibility, and more significant metal redistribution, probably due to its stronger chemical reactive capacity to AVS and sediment organic matter. The reactions in CaO₂-treated sediment would probably shift from physicochemical to biochemical heterotrophic oxidation for sediment organic matter degradation. Therefore, further investigation on the long-term metal redistribution and associated mobility as well as bioavailability is recommended.

The concentration and chemical speciation of arsenic (As) in different environmental matrixes (water, sediment, agricultural soils, and non-agricultural soils) were investigated in the Nanpan River area, the upstream of Pearl River, China. The results did not show any obvious transport of As along the flow direction of the river (from upstream to downstream). Total As concentrations in sediment were significantly different from those in agricultural soil. According to the comparison to quality standards, the As in sediments of the studied area have potential ecological risks and a minority of the sampling sites of agricultural soils in the studied area were polluted with As. As speciations were analyzed using sequential extraction and the percentage of non-residual fraction in sediment predominated over residual fraction. We thus believe that As in the studied area was with low mobility and bioavailability in sediment, agricultural soils, and non-agricultural soils. However, the bioavailability and mobility of As in sediment were higher than in both agricultural and non-agricultural soils, and thus, special attention should be paid for the risk assessment of As in the river in future studies.

A novel aspect of the 8th International PCB Workshop at Woods Hole, MA, was the interaction between scientists and activists. While earlier workshops in this series had mentioned policy making, this Workshop focused on the problem of PCBs in schools. Focus on a problem brought an activist to give a plenary talk and facilitated a 1-day registration for other non-scientists to attend. The workshop was cohosted by the Superfund Research Programs at University of Iowa and Boston University and included active participation of each Program’s Research Translation and Community Engagement Cores. A mandate of each National Institute of Environmental Health Science (NIEHS)-funded Superfund Research Program is bidirectional communication between scientists and community groups. The authors describe the events leading up to community involvement in the Workshop and the substance of the community engagement aspects of the workshop, in particular the participation by a parent-teacher group, Malibu Unites. The authors also discuss the value of such communication in terms of making important research accessible to those who are most affected by the results and poised to use it and the value of making scientists aware of the important role they play in society in addressing difficult questions that originate in community settings.

This study evaluated the use of sugarcane filter cake and nitrogen, phosphorus and potassium (NPK) fertilization in the bioremediation of a soil contaminated with diesel fuel using a completely randomized design. Five treatments (uncontaminated soil, T1; soil contaminated with diesel, T2; soil contaminated with diesel and treated with 15 % (wt) filter cake, T3; soil contaminated with diesel and treated with NPK fertilizer, T4; and soil contaminated with diesel and treated with 15 % (wt) filter cake and NPK fertilizer, T5) and four evaluation periods (1, 60, 120, and 180 days after the beginning of the experiment) were used according to a 4 × 5 factorial design to analyze CO₂ release. The variables total organic carbon (TOC) and total petroleum hydrocarbons (TPH) remaining in the soil were analyzed using a 5 × 2 factorial design, with the same treatments described above and two evaluation periods (1 and 180 days after the beginning of the experiment). In T3 and T5, CO₂ release was significantly higher, compared with the other treatments. Significant TPH removal was observed on day 180, when percent removal values were 61.9, 70.1, 68.2, and 75.9 in treatments T2, T3, T4, and T5, respectively, compared with the initial value (T1).

Anthropic activities generate contaminants, as pesticides and other pollutants, in the aquatic environment which present a real threat to ecosystems and human health. Thus, monitoring tools become essential for water managers to detect these chemicals before the occurrence of adverse effects. In this aim, algal cell biosensors, based on photosystem II activity measurement, have been designed for several years in previous studies. In this work, we study a new immobilization technique of algal cells in the aim of improving the performance of these biosensors. Immobilization was here achieved by encapsulation in a hybrid alginate/silica translucid hydrogel. The feasibility of this process was here assessed, and the biosensor designed was tested on the detection of chemicals in urban rainwaters.

One technique applied to restore degraded or contaminated soils is to use amendments made of different types of waste materials, which in turn may contain metals such as Cu, Pb and Zn. For this reason, it is important to determine the capacity of the soil to retain these materials, and to compare the sorption capacity between an amended soil and another unamended soil. The aim of this study was to determine the mobility and availability of these metals in the soil after applying the amendment, and how it affected the soil’s sorption capacity. Sorption isotherms were compared with the empirical models of Langmuir and Freundlich to estimate the sorption capacity. The overall capacity of the soils to sorb Cu, Pb or Zn was evaluated as the slope Kr. The amendments used in this study were a mixture made of compost and biochar in different proportions (20, 40, 60, 100 %), which were applied to the mine tailing from a settling pond from a copper mine. The mine tailing that were amended with the mixture of compost and biochar had a higher sorption capacity than the mine tailing from the unamended pond, and their sorption isotherms had a greater affinity towards Cu, Pb and Zn than the mine tailing that was studied. Therefore, the results obtained show that adding a mixture of compost and biochar favours the retention of Cu, Pb and Zn in mine tailing.

The photodegradation of diethyl phthalate (DEP) by UV/H₂O₂ and UV/TiO₂ is studied. The DEP degradation kinetics and multiple crucial factors effecting the clearance of DEP are investigated, including initial DEP concentration ([DEP]₀), initial pH values (pH₀), UV light intensity, anions (Cl⁻, NO³⁻, SO₄ ²⁻, HCO₃ ⁻, and CO₃ ²⁻), cations (Mg²⁺, Ca²⁺, Mn²⁺, and Fe³⁺), and humic acid (HA). Total organic carbon (TOC) removal is tested by two treatments. And, cytotoxicity evolution of DEP degradation intermediates is detected. The relationship between molar ratio ([H₂O₂]/[DEP] or [TiO₂]/[DEP]) and degradation kinetic constant (K) is also studied. And, the cytotoxicity tests of DEP and its degradation intermediates in UV/H₂O₂ and UV/TiO₂ treatments are researched. The DEP removal efficiency of UV/H₂O₂ treatment is higher than UV/TiO₂ treatment. The DEP degradation fitted a pseudo-first-order kinetic pattern under experimental conditions. The K linearly related with molar ratio in UV/H₂O₂ treatment while nature exponential relationship is observed in the case of UV/TiO₂. However, K fitted corresponding trends better in H₂O₂ treatment than in TiO₂ treatment. The Cl⁻ is in favor of the DEP degradation in UV/H₂O₂ treatment; in contrast, it is disadvantageous to the DEP degradation in UV/TiO₂ treatment. Other anions are all disadvantageous to the DEP degradation in two treatments. Fe³⁺ promotes the degradation rates significantly. And, all other cations in question inhibit the degradation of DEP. HA hinders DEP degradation in two treatments. The intermediates of DEP degradation in UV/TiO₂ treatment are less toxic to biological cell than that in UV/H₂O₂ treatment.