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5 mg/L, 1 mg/L, and 3 mg/L respectively. They are able to meet the China Ministry of Environment Protection (MEP) regulatory limit. With the increase of the curing time, the unconfined compressive strength and the leaching concentrations of these pastes showed a slightly increasing trend. In addition, SEM and TGA analyses show that the major hydration product is ettringite. This study describes the development of a sequential extraction procedure for the evaluation of metal nanoparticle mobility and bioaccessibility in soils. The procedure, that was developed using gold nanoparticles (AuNPs) as model species, relies on the fractionation of nanoparticles by sequentially dissolving soil matrix components (carbonates, metal oxides, organic matter and mineral phases) in order to release the entrapped nanoparticle species in the extract solution. By summing up the concentration of AuNPs recovered in each fraction it was found that 93.5% of the spiked AuNP concentration could be recovered which satisfactorily represents the nominal AuNP concentration in the soil. The efficiency of the procedure was found to depend on several procedural artifacts related to the separation of AuNPs from soil colloids and the reactivity of the extraction reagents with AuNPs and their precursor metal ions. Based on the results obtained a protocol for the speciation of the AuNPs and Au ions in the soil sample was also developed. The results of the study show that both AuNPs and Au ions are mainly associated with soil organic matter, which significantly reduces their mobility, while a small amount ( less then 10%) is associated with metal oxides which are more mobile and potentially bioaccessible. The developed procedure provides a springboard for further development of sequential extraction procedures of metal nanoparticles in soils that could be used to assess both the exposure and release of metal nanoparticles and their precursor metal ions in the environment (as total extractable concentration) as well as provide evidence regarding their bioaccessibility and potential bioavailability by determining the concentration of nanoparticles in each specific soil fraction. To help countries worldwide regulate agricultural soil standards for organic contaminants, this study developed the pastoral-based chemical lifecycle management (PBCLM) modeling framework, which comprehensively models the bottom-up causation of the chemicals' lifecycle at each level of the cattle industry and delivers top-down regulatory strategies. The lifecycle models for a total of 308 hydrophobic organic contaminants were constructed. The results indicated that the octanol-water partitioning coefficient (log KOW) values had the greater impact on the unit-legal-limit-based concentrations for contaminants at the producer level (i.e., grass) or higher. In addition, the analysis of the weather variables indicated that pastoral farming in warmer and drier places might lead to the bioaccumulation of more contaminants. By comparing the reference legal limits that were derived by the PBCLM, current soil standards might not be effective in protecting human health or harmonizing downstream food regulations. The PBCLM can help regulatory agencies better promulgate soil regulations to ensure sustainable agriculture. Recent reports are pointing towards the potential increasing risks of resistomes in human host. With no permissible limit in sight, resistomes are continually multiplying at an alarming rate in the ecosystem, with a disturbing level in drinking water source. The morphology and chemical constituent of resistomes afford them to resist degradation, elude membrane and counter ionic charge, thereby, rendering both conventional and advanced water and wastewater treatment inefficient. Water and wastewater matrix may govern the propagation of individual resistomes sub-type, co-selection and specific interaction towards precise condition may have enhanced the current challenge. selleck inhibitor This review covers recent reports (2011-2019) on the occurrence of ARB/ARGs and ease of spread of resistance genes in the aquatic ecosystem. The contributions of water matrix to the spread and mitigation, treatment options, via bulk removal or capture, and intracellular and extracellular DNA lysis were discussed. A complete summary of recent occurrences of ARB/ARGs, fate after disinfection and optimum conditions of individual treatment technology or in tandem, including process limitations, with a brief assessment of removal or degradation mechanism were highlighted. As emerging pollutants, the occurrence and risks of organophosphate esters (OPEs) in mariculture farms should be concerned; however, information is limited. Beibu Gulf is one of the essential mariculture zones in China. This study aimed to investigate the occurrence of OPEs in mariculture farms of the Beibu Gulf, their phase distribution and bioaccumulation among sediment, organisms (shrimp, crab, and oyster), water, and feed. Human exposure to OPEs through seafood consumption was also assessed. The total concentrations of the 11 target OPEs (∑11OPEs) in the water samples ranged 32.9-227 ng L-1. It was significantly higher in water from the culture ponds (mean 122 ng L-1) than in water from the estuaries and nearshore areas (mean 51.1 ng L-1) (nonparametric test, p  less then  0.05). ∑11OPEs in the feeds averaged 46.0 (range 21.7-84.5) ng g-1 dw, which is similar to the level in the organism samples (mean 55.5, range 21.3-138 ng g-1 dw) and 4.4 times higher than that in the sediment (mean 10.9, range 35-22.1 ng g-1 dw). The ∑11OPEs released from the feeds to the culture ponds was estimated to be 49 μg m-2 per three-month period. In the aquaculture ponds, the sediment-water distribution coefficient (log KOC), and the bioaccumulation factors from the water (log BWAFs) or the feed (log BFAFs) to the organisms, depend linearly on the hydrophobicity (log KOW) of OPEs. The log BWAFs and log BFAFs increased with increasing log KOW within the log KOW range of 1-7. The human exposure to OPEs through consumption of shrimp, crab, and oysters from the mariculture farms does not pose a health risk at present.