Microbially induced carbonate precipitation (MICP) is an emerging and promising bioremediation technology to restore the environment polluted by heavy metals. Carbonate-biomineralization microbe can immobilize heavy metals from mobile species into stable crystals. In the present manuscript, laboratory batch studies were conducted to evaluate the Cd removal ability based on biosorption and MICP, using carbonate-biomineralization microbe GZ-22 isolated from a mine soil. This strain was identified as a Bacillus sp. according to 16S rDNA gene sequence analysis. Results of batch experiments revealed that MICP of the strain GZ-22 showed a greater potential to remove Cd than biomass biosorption under different impact factors such as pH, initial Cd concentration, and contact time. The optimum pH for MICP was 6 (50.34 %), while for biomass biosorption, it was 5 (38.81 %). When the initial concentration of Cd was 10 mg/L, removal efficiency induced by MICP was 53.06 % after 3 h, which was about 11 % greater than the removal efficiency induced by adsorption. The Cd removal efficiency increased as reaction time. The maximum removal efficiency based on MICP can reach 60.72 % at 10 mg/L for 48 h compared with 56.27 % by biosorption. X-ray diffractomer (XRD) revealed that Cd was transformed into CdCO₃ by MICP of GZ-22. The present illustrated that the carbonate-biomineralization microbe GZ-22 can offer an effective and eco-friendly approach to immobilize soluble Cd and that MICP may play an important role in heavy metal bioremediation.

Ozone dynamics in two urban background atmospheres over middle Indo-Gangetic Plain (IGP) were studied in two contexts: total columnar and ground-level ozone. In terms of total columnar ozone (TCO), emphases were made to compare satellite-based retrieval with ground-based observation and existing trend in decadal and seasonal variation was also identified. Both satellite-retrieved (Aura Ozone Monitoring Instrument-Differential Optical Absorption Spectroscopy (OMI-DOAS)) and ground-based observations (IMD-O₃) revealed satisfying agreement with OMI-DOAS observation over predicting TCO with a positive bias of 7.24 % under all-sky conditions. Minor variation between daily daytime (r = 0.54; R ² = 29 %; n = 275) and satellite overpass time-averaged TCO (r = 0.58; R ² = 34 %; n = 208) was also recognized. A consistent and clear seasonal trend in columnar ozone (2005–2015) was noted with summertime (March–June) maxima (Varanasi, 290.9 ± 8.8; Lucknow, 295.6 ± 9.5 DU) and wintertime (December–February) minima (Varanasi, 257.4 ± 10.1; Lucknow, 258.8 ± 8.8 DU). Seasonal trend decomposition based on locally weighted regression smoothing technique identified marginally decreasing trend (Varanasi, 0.0084; Lucknow, 0.0096 DU year⁻¹) especially due to reduction in monsoon time minima and summertime maxima. In continuation to TCO, variation in ground-level ozone in terms of seasonality and precursor gases were also analysed from September 2014 to August 2015. Both stations registered similar pattern of variation with Lucknow representing slightly higher annual mean (44.3 ± 30.6; range, 1.5–309.1 μg/m³) over Varanasi (38.5 ± 17.7; range, 4.9–104.2 μg/m³). Variation in ground-level ozone was further explained in terms water vapour, atmospheric boundary layer height and solar radiation. Ambient water vapour content was found to associate negatively (r = −0.28, n = 284) with ground-level ozone with considerable seasonal variation in Varanasi. Implication of solar radiation on formation of ground-level ozone was overall positive (Varanasi, 0.60; Lucknow, 0.26), while season-specific association was recorded in case of atmospheric boundary layer.

The aim of this study was to assess the health impacts related to particulate matter less than 10 μm (PM₁₀) exposure in the city of Yazd, Iran. For this aim, AirQ 2.2.3 software was used to model relationship between short-term exposure to PM₁₀ and disease cases proposed by the World Health Organization (WHO). The annual mean concentration of PM₁₀ was 97 μg/m³. The maximum concentration value of PM₁₀ was measured during the summer (731 μg/m³). 4.988% (95%CI: 3.381–6.542%) of the total mortality, 7.3% (95%CI; 4.19–10.21%) of cardiovascular mortality, and 10.21% (95%CI; 4.19–14.89%) of respiratory mortality were related to the PM₁₀ concentrations. Consequently, the AirQ software can provide valuable information about the importance of air pollution and the substantial impacts of PM₁₀ on the society for policymakers.

The objective of the present experiment was to investigate the effect of bentonite supplementation in lead (Pb)-exposed lambs on serum Pb, Ca, P, Cu, Zn, and Fe concentrations, blood hematological parameters, and hepatic enzymes. Twenty Zandi male lambs (initial BW, 17.5 ± 1.6 kg) were randomly assigned to one of the four treatments: (1) control (no Pb or bentonite), (2) 15 mg/kg DM Pb as Pb acetate with no bentonite, (3) 15 mg/kg DM Pb as Pb acetate with 1.5% bentonite, and (4) 15 mg/kg DM Pb as Pb acetate with 3% bentonite. The experiment lasted after 90 days. Lead intake resulted in a decrease (P < 0.05) in serum Fe and an increase in serum Pb, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) activities (P < 0.05). Bentonite supplementation at 1.5 or 3% of DM decreased blood Pb concentration (P < 0.01) in lambs fed diets containing Pb and reduced (P < 0.05) blood concentration of Cu and Zn compared to control group (P < 0.01). However, the hematological parameters were not affected by any of the treatments. Our results showed that the dietary supplementation of bentonite could protect lambs against lead toxicity.

Two addition modes were used to explore the maximum addition of municipal sewage sludge as a raw material in cement clinker production. The clinker and cement product quality were determined by chemical analysis, cement quality testing, characterization of the clinker crystalline phases, and leaching tests. Municipal sewage sludge addition in the raw mix could be up to 30% based on the cement clinker moduli, and the cement quality met the P.O 42.5 cement standard (GB 175-2007). The amount of municipal sewage sludge added based on the direct addition mode should be less than 15% because of an insufficient early-term cement strength (third day). The leaching concentrations of heavy metals in all cements were below the threshold (GB 30760-2014) using the latest leaching procedure (GB 30810-2014). The municipal sewage sludge could be used with a high addition (30%) in the raw mix as a raw material in cement clinker production.

More widespread use of metallothionein (MT) as a biomarker for trace metal pollution continues to be partly dependent on obtaining reliable baseline concentrations and identifying increased induction of the enzyme with only modest increases in metal concentrations. In this study, new data on metals and MT levels in whole clams tissue, gills, and digestive glands from field samples and in sediments are presented. Concentrations of Cd, Cu, Fe, and Zn in depurated (24 h) clam samples of digestive glands, gills, and the whole clam Merceneria merceneria from the Indian River Lagoon, Florida, varied with location and showed moderate to strong correlations among Zn, Cu, and Fe. Concentrations of metallothionein (dry wt.) ranged from 34─270 μg/g in gills and 150–440 μg/g in digestive glands and showed moderate to strong correlations between organs and with metal concentrations in those organs. Observed trends support increased synthesis of metallothionein with only moderate increases in metal values and in response to statistically higher sediment metal concentrations.

Guiyu is a well-known electronic waste dismantling and recycling town in south China. Concentrations and distribution of the 21 mineral elements and 16 polycyclic aromatic hydrocarbons (PAHs) collected there were evaluated. Principal component analyses (PCA) applied to the data matrix of PAHs in the soil extracted three major factors explaining 85.7% of the total variability identified as traffic emission, coal combustion, and an unidentified source. By using metallic or metalloid element concentrations as variables, five principal components (PCs) were identified and accounted for 70.4% of the information included in the initial data matrix, which can be denoted as e-waste dismantling-related contamination, two different geological origins, anthropogenic influenced source, and marine aerosols. Combining the 21 metallic and metalloid element datasets with the 16 PAH concentrations can narrow down the coarse source and decrease the unidentified contribution to soil in the present study and therefore effectively assists the source identification process.

Lime or dolomite is commonly implemented to ameliorate soil acidity. However, the impact of dolomite on CO₂ emissions from acidic soils is largely unknown. A 53-day laboratory study was carried out to investigate CO₂ emissions by applying dolomite to an acidic Acrisol (rice-rapeseed rotation [RR soil]) and a Ferralsol (rice-fallow/flooded rotation [RF soil]). Dolomite was dosed at 0, 0.5, and 1.5 g 100 g⁻¹ soil, herein referred to as CK, L, and H, respectively. The soil pH₍H₂O₎ increased from 5.25 to 7.03 and 7.62 in L and H treatments of the RR soil and from 5.52 to 7.27 and 7.77 in L and H treatments of the RF soil, respectively. Dolomite application significantly (p ≤ 0.001) increased CO₂ emissions in both RR and RF soils, with higher emissions in H as compared to L dose of dolomite. The cumulative CO₂ emissions with H dose of dolomite were greater 136% in the RR soil and 149% in the RF soil as compared to CK, respectively. Dissolved organic carbon (DOC) and microbial biomass carbon (MBC) increased and reached at 193 and 431 mg kg⁻¹ in the RR soil and 244 and 481 mg kg⁻¹ in the RF soil by H treatments. The NH₄ ⁻-N and NO₃ ⁻-N were also increased by dolomite application. The increase in C and N contents stimulated microbial activities and therefore higher respiration in dolomite-treated soil as compared to untreated. The results suggest that CO₂ release in dolomite-treated soils was due to the priming of soil C content rather than chemical reactions.

The disturbance of the water-sediment interface by wind-driven currents and waves plays a critical role in sediment resuspension and internal nutrient release in large, shallow lakes. This study analyzed the effects of the interactions between wind-induced currents an1d waves on the driving mechanism of sediment resuspension in Lake Taihu, the third largest freshwater lake in China, using acoustic and optic techniques to collect long-term, high-frequency, synchronous in situ measurements of wind, currents, waves, and suspended solid concentrations (SSCs). The results suggested that water turbidity started to increase at wind speeds of approximately 4 m/s and significantly increased when wind speeds exceeded 6 m/s. In most cases, wind-induced waves were the main energy source for changes in turbidity. Wave-generated shear stress contributed more than 95% to sediment resuspension and that only in weak wind conditions (<4 m/s) did the lake bottom shear stresses generated by currents and waves contributed equally. The relationship between SSC and bottom shear stress generated by wave was established by fitting the observed results. The processes of sediment dynamics were divided into four stages (A through D) according to three shear-stress thresholds. In stage A, SSC remained stable (about 45 mg/L) and τw was less than 0.02 N/m². In stage B, the sediment bed was starting to be activated (SSC 45∼60 mg/L) and τw was in the range of 0.02∼0.07 N/m². In stage C, a medium amount of sediment was suspended (SSC 60∼150 mg/L) and τw ranged from 0.07 to 0.3 N/m². In stage D, large amount of sediment was suspended (SSC 150∼300 mg/L) and τw was larger than 0.3 N/m². The findings of this paper reveal the driving mechanism of sediment resuspension, which may further help to evaluate internal nutrient release in large shallow Lake Taihu.

Fresh surface water supplies are gradually becoming insufficient in arid and semi-arid regions of the world. Thus, farmers in these areas are being forced to use poor quality sewage water. Irrigating vegetable crops with sewage water having high metal concentration may affect growth and biochemical processes of plants. Biochar (BC) can sorb these metals and may reduce their toxic effects on plants. Thus, a greenhouse experiment was conducted to study the influence of cotton stalks derived biochar (CSDB) at control (0%) and 1%; ground water (GW; 0.01 ppm Cd); cadmium-contaminated water (CCW; 2 ppm Cd); and sewage water (SW; 0.13 ppm Cd) on growth and biochemical processes of tomato (Solanum lycopersicum) plants. On an average, additions of 1% BC significantly (p ≤ 0.05) enhanced dry weight of roots (36%) and shoots (52%) of plants as compared to without BC application. Biochar (1%) decreased shoot Cd concentration by 33% at SW and 100% at CCW. The Cd uptake was increased by 33% with the BC + CCW treatment. Soil organic matter (SOM) was increased 1.2 times while pH and EC were increased by 5 and 47%, respectively, in 1% BC amended soil. Biochar application alleviated toxic effects of Cd and improved growth as well as productions of photosynthetic and accessory pigments in tomato plants.