Lightweight building bricks manufactured from non-hazardous residues incorporating mineral foaming agents have been successfully developed over past two decades. Very little information is available on recycling and reutilization of construction and demolition waste used as the pore foaming agent in manufacturing lightweight brick. In this research, the mineral swelling agent was gypsum board recycled from construction and demolition waste. The mineral swelling agent effect on the characteristics of green lightweight building materials sintered from drinking water purification (DWP) sludge was investigated. Green lightweight building materials were contained up to 50% (wt%) mineral swelling agent and fired at a temperature ranged between 950 °C and 1050 °C. The experimental results indicated that lightweight building materials have successfully sintered between 1000 °C and 1020 °C and added up to 40% (wt%) recycled gypsum board. The sintered building materials have the characteristics of relatively high compressive strength, low bulk density, and thermal conductivity that were in compliance with relevant Taiwan criteria for application in lightweight building materials. To further consider the eco-friendly and environmental safety of lightweight building materials, the recycled gypsum board can act as a good mineral swelling agent, but can also enhance the chemical stabilization and reduce the metals leachability of lightweight materials based on acidic neutralization capacity (ANC) analysis results. To estimate the carbon dioxide emission in manufacturing and transportation of lightweight materials that sintered this experimental conditions, the estimated carbon dioxide reduction rates were approximately 28.6% and 16.7%, respectively, as a result of the energy saving. Experimental results have confirmed that the feasibility of recycled gypsum board used as a swelling agent and good potential for construction works in green lightweight building materials.

The new design of internal flotation components and the use of biogas were employed to develop a novel anaerobic self-flotation (ASF) reactor. Compared with the upflow anaerobic sludge blanket (UASB) reactor, the removal efficiencies of total chemical oxygen demand (COD) and suspended solids (SS) of the ASF reactor were higher than 90% under high SS concentration and high volumetric organic loading rate (OLR). The biogas flotation, sludge bed retention, and effluent washout accounted for 60%, 30%, and 10% of SS mass, respectively, proving that the biogas flotation was the main mechanism of SS removal in the ASF reactor. Extracellular polymer substance, mainly consisting of polysaccharide (PS) and protein (PN), was found to promote the SS removal by biogas flotation via the scum formation at the ratio of 294.12 g-VS/g-PS and 103.09 g-VS/g-PN. The EPS yield was determined as 2.3 ± 0.6 g-PS/g-COD and 11.5 ± 2.6 g-PN/g-COD at the OLR of 60 kg/(m³ day). The biogas production was revealed to enhance the SS removal by providing flotation driving force and by decreasing the scum density. A model was established to describe the quantitative relationship between flotation scum and OLR. This work would shed light on the high SS wastewater treatment challenge of high-rate anaerobic processes by using biogas flotation.

Perfluorooctane sulfonate (PFOS), a hepatotoxic pollutant, is detected in the human cord blood, and it may induce health risk to an embryo. In this study, we established intrauterine exposure to PFOS in mice to evaluate potential impacts of PFOS on postnatal day 1 (PND1) offspring through conducting biochemical tests, quantitative PCR, and immunostaining. As results, PFOS-exposed maternal mice showed marked hepatomegaly and induced liver steatosis in a high dose of 5 mg PFOS/kg. In PND1 mice, intrahepatic contents of triglyceride, total cholesterol, and LDL were elevated by high-dose PFOS exposure, while intracellular HDL content was decreased. As shown in quantitative PCR, functional messenger RNAs of cytochrome P4A14 (CYP4A14) for fatty acid oxidation, CD36 for hepatic fatty acid uptake, and apolipoprotein B100 (APOB) and fibroblast growth factor 21 (FGF21) for hepatic export of lipids in PND1 livers were changed when compared to those in PFOS-free controls. In further validations, immunofluorescence stains showed that hepatic CYP4A14 and CD36 immunoreactive cells were increased in PFOS-exposed PND1 mice. In addition, reduced immunofluorescence-positive cells of APOB and FGF21 were observed in PND1 livers. Collectively, these preliminary findings demonstrate that prenatal exposure to PFOS may affect lipid metabolism in liver cells of PND1 mice.

The purpose of this study is to evaluate the health effect of heavy metal pollution in air pollutants on traffic policemen. This study will facilitate the scientific evaluation of health status of traffic policemen. PM₁₀ samples were collected from industrial area, congested traffic area and residential area respectively in Nanchang City, and the concentrations of heavy metals were analyzed. The traffic policemen were examined through chest X-rays. The total of 637 urine samples and 142 blood samples have been collected, and the concentrations of Pb in samples were detected. Vehicle flux data of Nanchang City were collected from the Department of Transport’s Traffic Management. Statistic analyses were carried out by statistics software of Excel 2003 and SPSS20.0, and the health effect of heavy metal pollution of PM₁₀ on the traffic policemen was evaluated. The discharge of pollutants from enterprises is an important reason for the high content of heavy metals in urban air pollution. With the rapid growth of urban traffic flow, Bayi Bridge becomes an important transportation hinge in Nanchang City, and the bidirectional traffic flow rate through the bridge at peak hours reached 99 vehicles per minute. The latent hazard of occupational harm on the traffic policemen caused by automobile exhaust is increasing. The concentration of Pb in the urine and blood samples from traffic policemen working in Nanchang City was 268.310 ± 177.031 and 22.873 ± 21.137 μg/L, respectively. Both results (2.04% of Pb in urine and 18.31% of Pb in blood) exceeded the highest limit of observed occupationally outdoor workers. This study provides an initial contribution for the assessment of city air pollution, esp. the health effect of heavy metal (Pb) pollution on traffic policemen.

A wide range of endocrine disruptor compounds are routinely discharged to the ecosystem. Water contaminated with these compounds has a potential effect on the reproductive physiology of aquatic organisms as well as humans. In the present study, we tested the effect of the steroid estrogen, 17β-estradiol, on Biomphalaria alexandrina, a snail species that is widely distributed in Egypt and that acts as an intermediate host for the human blood fluke, Schistosoma mansoni. The effects of exposure to 0.3 mg/L and 1 mg/L 17β-estradiol on fecundity (MX) and reproductive rate (R₀) of B. alexandrina were recorded. In addition, levels of steroid sex hormones and antioxidants in the hemolymph and ovotestis (OT) of exposed snails were measured. Histopathological changes in the OT of B. alexandrina were also investigated. Exposure to 0.3 mg/L and 1 mg/L 17β-estradiol caused a significant increase in the number of egg masses per snail after 3 weeks and 1 week of exposure for the two tested concentrations compared with unexposed controls. An increase in the levels of progesterone hormone was recorded in the hemolymph of exposed snails in comparison with unexposed controls. Additionally, levels of the antioxidant enzyme glutathione (GSH) were increased in the hemolymph and OT tissues of snails after 2 and 4 weeks of exposure. Histopathological sections in the OT revealed an increase in the oocyte and a decrease in the sperm densities after 2 weeks and this effect was restored to normal conditions after 4 weeks of exposure to both tested concentrations. The current results indicate that B. alexandrina is sensitive to 17β-estradiol and can therefore be used as bioindicator and model organism for the assessment of water pollution with endocrine disruptor compounds.

Identifying the sources of volatile organic compounds (VOCs) is key to air quality control and pollution prevention. Though receptor models have been widely used in source apportionment of VOCs, they are not applicable to identify the potential source of labile species. In this study, the potential source of methyl mercaptan (MeSH) near a large refining and petrochemical plant was identified using an indirect method. When wind directions were controlled, the study period was separated into two subperiods depending on the detection of MeSH. Relative contributions from potential sources were predicted by chemical mass balance model and positive matrix factorization model based on ambient concentrations of sulfur-free compounds. Both models predicted that petroleum refinery and petrochemical production were the dominant sources of VOCs in the study area. When MeSH was detected, the relative contribution from gasoline, liquefied petroleum gas, or crude oil increased by 7.4 to 26.8% point, depending on wind direction and the predictive model used, suggesting a close relationship between MeSH and the emission from petroleum refinery. Consistent with the indirect source apportionment, among the coexisting VOCs, MeSH was most highly correlated or associated with ethane, propane, isobutane, cis-2-pentente, and isoprene, which are major components of the products or by-products of petrochemical refining processes.

Deterring the spread of invasive fishes is a challenge for managers, and bigheaded carp (including bighead and silver carp, Hypophthalmichthys spp.) are invasive fish that have spread throughout large portions of the Mississippi River basin and threaten to invade the Great Lakes’ ecosystem. Studies have shown that elevated levels of carbon dioxide gas (CO₂) have the ability to act as a nonphysical fish barrier, but little work has been done on the efficacy of CO₂ to deter fish movement in flowing water. An annular swim flume was used to measure Ubᵤᵣₛₜ and sprint duration of the model species largemouth bass (Micropterus salmoides) across a range of pCO₂ levels (< 400 μatm [ambient]; 10,000 μatm; 50,000 μatm; and 100,000 μatm). This species was tested as a proxy because of the likelihood of a similar CO₂ response being produced, as well as constraints in obtaining and housing appropriately sized Asian carp. A significant decrease in Ubᵤᵣₛₜ swimming occurred when exposed to 100,000 μatm. No effects on sprint duration were detected. In both swimming tests, 15% of fish lost equilibrium when exposed to 50,000 μatm pCO₂, while 50% of fish lost equilibrium when exposed to 100,000 μatm. Together, results define target levels for managers to impede the spread of largemouth bass and potentially other invasive freshwater fishes, helping guide policy to conserve aquatic ecosystems.

To investigate the molecular response of ancient plants to heavy metal stress and to explore the feature of DNA methylation in endangered plants after exposure to heavy metals, the Isoetes sinensis, an endangered plant, was stressed with three different concentrations of two heavy metals lead (Pb) and cadmium (Cd), respectively. Then the degrees and the patterns of DNA methylation in the leaves were measured on the 14th day using Methylation Sensitive Amplified Polymorphism (MSAP) technique. The results showed that the DNA methylated profile of I. sinensis was affected by Pb and Cd stress. There was no significant difference in the amount of DNA methylation among control check (CK), Pb stress group, and Cd stress group (CK 46.96%, Pb 48.23%, and Cd 48.1%). However, full-methylation level of Pb stress group (28.34%) and Cd stress group (20.25%) was lower than control (33.91%), in contrast, hemi-methylation level Pb stress group (19.89%) and Cd stress group (27.85%) were higher than control (13.04%). The change of patterns from no methylation or hemi-methylation of internal and external cytosines into full-methylation of internal and external cytosines accounted for a large proportion in enhanced methylation aspects. The full-methylation into no methylation or hemi- or full-methylation of internal and external cytosines occupied most of demethylation. The proportion of DNA methylation (including hypermethylation) by both Pb and Cd stresses is nearly equal (39.04% and 39.71%), but the proportion of DNA demethylation by Cd is higher than that by Pb (46.86% than 33.92%).

Typical biological processing is often challenging for removing ammonia nitrogen and phosphate from swine wastewater due to inhibition of high ammonia on activity of microorganisms, exhaustion of time, and low efficiency. In this study, a physicochemical process by combining ammonia stripping with struvite precipitation has been tested to simultaneously remove ammonia nitrogen, phosphate, and chemical oxygen demand (COD) from digested swine wastewater (DSW) with high efficiency, low cost, and environmental friendliness. The pH, temperature, and magnesium content of DSW are the key factors for ammonia removal and phosphate recovery through combining stripping with struvite precipitation. MgO was used as the struvite precipitant for NH₄⁺ and PO₄³⁻ and as the pH adjusted for air stripping of residual ammonia under the condition of 40 °C and 0.48 m³ h⁻¹ L⁻¹ aeration rate for 3 h. The results showed that the removal efficiency of ammonia, total phosphate, and COD from DSW significantly increased with increase of MgO dosage due to synergistic action of ammonia stripping and struvite precipitation. Considering the processing cost and national discharge standard for DSW, 0.75 g L⁻¹ MgO dosage was recommended using the combining technology for nutrient removal from DSW. In addition, 88.03% NH₄⁺-N and 96.07% TP could be recovered from DSW by adsorption of phosphoric acid and precipitation of magnesium ammonium phosphate (MAP). The combined technology could effectively remove and recover the nutrients from DSW to achieve environmental protection and sustainable and renewable resource of DSW. An economic analysis showed that the combining technology for nutrient removal from DSW was feasible.