The effects of solid content (10–80 g/L) on the bioleaching of heavy metals (HMs) from pig manure (PM) were investigated using indigenous sulfur-oxidizing bacteria. The results showed that an increase in solid content increased the PM buffering capacity, which slowed the rates of pH reduction, ORP increase, and sulfur oxidation and decreased the solubilization efficiency of HMs from PM. Approximately 75–99% of Cu, 76–99% of Zn, and 55–88% of Mn were leached from PM with solid contents of 10–80 g/L after 28 days of bioleaching. However, the content of HMs in bioleached manure did not meet the requirement for agricultural application when the solid content was ≥ 60 g/L after 28 days of bioleaching. The solubilization of HMs from PM was well-described by a kinetic equation. Regression analysis showed that Cu solubilization was primarily controlled by ORP, and pH seemed to be the sole factor responsible for the solubilization of Zn and Mn. Additionally, nutrient (N, P, K, and organic matter) loss significantly increased when PM solid content decreased from 40 to 20 g/L. Therefore, the recommended solid content for the bioleaching of HMs from PM is 40 g/L.

Environmental reservoirs of fecal indicator bacteria (FIB) are attracting increasing attention because of the ambiguity they present when assessing the microbial quality of water. FIB can survive and even grow in various environmental reservoirs which means FIB measured in the water column may not have originated directly from a fecal source. Sediment and periphyton, i.e., aquatic biofilms growing on submerged rocks, have been shown to harbor large populations of FIB in the environment. However, little is known about the spatial and temporal dynamics of FIB in periphyton. The objective of this work was to determine levels of the common FIB, Escherichia coli and enterococci, in creek water, sediment, and periphyton during the summer and winter. FIB were measured during two summer and winter sampling dates at five locations along a 2.8-km stretch of creek in Beltsville, Maryland. Significant differences in FIB by location were only observed for E. coli in water at one time point. Levels of FIB significantly declined from summer to winter in all media. FIB concentrations in periphyton ranged from 10² to 10⁴ gdw⁻¹ in the summer and from 10⁰ to 10⁴ CFU gdw⁻¹ in the winter. When compared on a dry weight basis, periphyton contained higher concentrations of FIB than the sediment. Variability of FIB was in the order of water < sediment < periphyton. Levels of E. coli and enterococci measured in the same sample showed significant positive correlation in all media (rₛ = 0.87, 0.48, 0.70, for water, sediment, and periphyton, respectively). Results from this work show that fecal bacteria can persist in creek periphyton which may act as both a reservoir for fecal pathogens as well as a probable source of fecal bacteria to the water column.

Recent efforts to aggregate, process, and use biodiversity information have appended novel opportunities and challenges for the field, and a rapid increase in studies that integrate and analyze data in the biological-ecological realm. We developed a web-based GIS system for the wildlife of Khouzestan Province that provides potential distribution maps and other spatial and nonspatial data on the wildlife of Khouzestan Province and its protected areas. We used MaxEnt and a fuzzy inference system to model distributions of species. Our application was structured using a client/server architecture, and the database design and construction was carried out using PostgreSQL/PostGIS, and GeoServer to serve maps. The mapping interface was developed using OpenLayers; ASP.NET was selected for designing the user interface. We used qualitative-quantitative methods to develop, design, refine, and finalize our system particularly as regards usability. The design approach resulted in a user-friendly interface that allows both specialists and non-specialists to quickly and efficiently run models to estimate potential distributions of species. Our application highlights what can be accomplished with a biodiversity-oriented web application.

To reduce the environmental pollution caused by ammonium paratungstate (APT) production in the Ganzhou area in China, simulated experiments in laboratory and field experiments in cement kilns were performed. The migration characteristics of As in secondary residues (thermometallurgy and hydrometallurgy residues) from APT production in cement kilns were similar, and As in the residues existed in the form of sulfides. When the residues were fed at the kiln inlet, the As in the residues was completely distributed in the clinker after a new mass balance of As was reestablished in a very short time. When the residues were fed at the raw mill, the total input rate of As was far higher than the total output rate. Therefore, a part of As was circulated in the cement kiln, and only a small part of As was distributed in the clinker. In addition, the As concentration in the flue gas and the leaching concentration of As in the clinker were far below the limit value in the Chinese standard. For feeding rates below that are used in the field experiment, co-processing of secondary residues in a cement kiln fed at the kiln inlet is environmentally safe. However, if the secondary residues are consistently fed at the raw mill, the As concentration in the flue gas may gradually increase.

Increasing environmental concern, human health and the continuous upgradation in the stringent standards of vehicular emissions have shown much interest in cleaner diesel fuels. Out of various strategies to mitigate the diesel engine emissions, use of water blended diesel in the form of emulsion has grabbed sufficient attention of the fuel research community. Various researches have shown that water-emulsified diesel has sufficient potential to improve the engine performance simultaneously with a significant reduction in the levels of nitrogen oxides (NOₓ) and particulate matter (PM) emissions. Micro-explosion phenomenon of combustion in emulsion fuel helps to provide efficient and complete combustion which in turn improves brake thermal efficiency. The current study presents a comprehensive review of the usage of water-emulsified diesel fuel in CI engines. Focusing on the performance, combustion, and emission analysis, it also talks in detail about the principle and the chemistry involved in making of a stable and homogeneous water–diesel emulsion compatible for CI engine. The literature survey concludes two crucial points. First, the water-blended diesel emulsion serves as an economical, fuel efficient, and cleaner combustion technology. Second, the optimum blend ratio, emulsifier quantity, and proper process differs in almost all the research papers and hence needed to be standardized.

In order to further understand the status of the water quality of Min River’s sea-entry section, the index systems for water environmental quality assessment was built based on twenty evaluation parameters including dissolved oxygen (DO), permanganate index (CODMₙ), chemical oxygen demand (CODCᵣ), biochemical oxygen demand (BOD₅), ammonia (NH₃-N), total phosphorus (TP), and total nitrogen (TN). Water environmental quality of Min River’s sea-entry section in 2015–2017 was evaluated by utilizing the entire-array-polygon synthesis illustration method, accompanied by the time-dependent trend analysis. The results demonstrated that the water environmental quality of Min River’s sea-entry section was between the levels I and II of the Environmental Quality Standards for Surface Water (EQSSW, GB3838-2002) in 2015–2017, indicating a generally good water quality. The water quality was affected by both natural factors (such as temperature, rainfall, and runoff) and human factors and had a tendency to deteriorate at the duration of 2015–2017. The research results are of great significance for further understanding of the discharge of pollutants from the Min River basin and will be a strong support for the scientific decision-making of marine management in Fujian Province.

We performed a time series analysis to investigate the potential association between exposure to ambient air pollution and type 2 diabetes (T2D) incidence in the Chinese population. Monthly time series data between 2008 and 2015 on ambient air pollutants and incident T2D (N = 25,130) were obtained from the Environment Monitoring Center of Ningbo and the Chronic Disease Surveillance System of Ningbo. Relative risks (RRs) and 95% confidence intervals (95% CIs) of incident T2D per 10 μg/m³ increases in ambient air pollutants were estimated from Poisson generalized additive models. Exposure to particulate matter < 10 μm (PM₁₀) and sulfur dioxide (SO₂) was associated with increased T2D incidence. The relative risks (RRs) of each increment in 10 μg/m³ of PM₁₀ and SO₂ were 1.62 (95% CI, 1.16–2.28) and 1.63 (95% CI, 1.12–2.38) for overall participants, whereas for ozone (O₃) exposure, the RRs were 0.78 (95% CI, 0.68–0.90) for overall participants, 0.78 (95% CI, 0.69–0.90) for males, and 0.78 (95% CI, 0.67–0.91) for females, respectively. Exposure to PM₁₀ and SO₂ is positively associated with T2D incidence, whereas O₃ is negatively associated with T2D incidence.

As we all know, geochemical data usually contain outliers and they are heterogeneous, which will severely affect the use of receptor models based on classical estimates. In this paper, an advanced modified RAPCS-RGWR (robust absolute principal component scores-robust geographically weighted regression) receptor model was introduced to analyze the pollution sources of eight heavy metals (Cd, Hg, As, Pb, Ni, Cu, Zn) in a city of southern China. The results showed that source identification and source apportionment are more consistent by this advanced model even though the soil types and farming patterns are diverse. Moreover, this model decreased the occurrence of negative values of the source contribution. For these reasons, the pollution sources were classified into five types by the new model in the study area: agricultural sources, industrial sources, traffic sources, comprehensive sources, and natural sources. (1) The contributions of agricultural sources to Cr and Ni were 243.36% and 242.61%, respectively; (2) the contribution of industrial sources to Cd was 79.25%; (3) the contribution of traffic sources to Cu was 100.31%; (4) the contributions of comprehensive sources to Hg, Pb, and Zn were 253.90%, 242.31%, and 93.32%, respectively; and (5) the contribution of natural sources to As was 208.21%. Overall, the RAPCS-RGWR receptor model improved the validity of the receptor models. It is of great realistic significance to understand and popularize the advanced model in soil source apportionment in agricultural land.

Biological materials play a significant role in the treatment of heavy metal-contaminated soil and wastewater. In this study, the Pb²⁺ biosorption potential of lichen Evernia prunastri, extensively available at a forest in Bilecik-Turkey, was investigated at batch-scale level. The optimal conditions were determined and the adsorption isotherms, kinetics, and thermodynamic calculations were also done. In order to have detailed knowledge about metal biosorption, SEM, FTIR, and BET analyses were carried out before and after the biosorption process. The optimal pH was found pH 4 and the maximum metal uptake capacity was found as 0.067 mol kg⁻¹. The results of this study indicate that the lichen was effectively applied to the removal of Pb²⁺ process as an inexpensive biosorbent from industrial wastewater.

A new adsorbent poly-3-hydroxybutyrate-2-(dodecylthiocarbonothioylthio)-2-methylpropionate triester (PH-DTT-MPT) was first time loaded in a micropipette tip for speciation of chromium in different water samples. Total chromium (Cr), trivalent chromium (Crᴵᴵᴵ), and hexavalent chromium (Crⱽᴵ) in different natural water samples were determined by electrothermal atomic absorption spectrometry. Known concentration of Crᴵᴵᴵ and Crⱽᴵ was passed through a biodegradable polymer for investigation of the behavior of the newly used adsorbent. The newly used copolymer absorbed the Crᴵᴵᴵ on surface of the PH-DTT-MPT at pH 7.0, while Crⱽᴵ was not adsorbed in desired pH value. After passing the real and standard solutions through the micropipette, then 2.0 mol L⁻¹ HCl was used for elution of Crᴵᴵᴵ from the biodegradable polymer. Total Cr was calculated after reducing Crⱽᴵ into Crᴵᴵᴵ by specific concentration of hydroxy ammonium chloride (HONH₂·HCl). The concentration of Crⱽᴵ in different natural water samples was estimated after back calculation of Crᴵᴵᴵ from total chromium. Effect of analytical parameters like adsorbent, pH, eluent, sample volume, flow rates, and interfering ions was also studied. The LOD, LOQ, RSD, and EF of the developed method were calculated as 6.1 ng L⁻¹, 20 ng L⁻¹, 1.17%, and 90, respectively. Validation of developed method was checked by certified reference materials and spiking addition method. The developed method was successfully applied for determination of total Cr, Crᴵᴵᴵ, and Crⱽᴵ in various natural water ecosystems.