The Tha Chin River is a branch river of the Chaophraya River, which is one of the four main rivers in the central area of Thailand. Currently, the Tha Chin River is experiencing serious problems regarding water quality. Our study was carried out to analyse the river quality status, classify the health of the river according to Water Quality Index (WQI) and assess the riverbank community’s understanding of the Tha Chin River water quality. The results indicated that the water quality in the estuary of the Tha Chin River has been seriously polluted. In addition, the results also found that the WQI of the wet period was significantly lower than that of the dry period at p-value < 0.05. While the results from the riverbank community’s understanding assessment revealed that they feel the water quality in this river is still good, especially in the upstream and the midstream. Therefore, the assessed water quality according to WQI method showed that the riverbank community had a misunderstanding of the water quality of the Tha Chin River.

A composite adsorbent was prepared by montmorillonite and biochar from peanut shell. The adsorption experiment of the Cu2+ ions from aqueous solution by the montmorillonite-biochar composite was carried out in detail. The effects of initial concentration of Cu2+ ions in aqueous solution and contact time on adsorption efficiency were studied. FTIR spectroscopy, SEM and TEM analyses, standard N2 adsorption-desorption techniques, EDS and XPS were used to evaluate the physico-chemical, textural and crystalline properties of the montmorillonite-biochar composite. Results showed that the montmorillonite-biochar composite was mesoporous material. The surface of montmorillonite-biochar composite was rough with irregular layer structure. According to the experimental data, pseudo first order kinetics model and pseudo second order kinetics model were applied. The adsorption process fits well with the pseudo second order kinetics model. The predominant process is chemisorption, which involves a sharing of electrons between the adsorbate and the surface of the adsorbent. Adsorption data were correlated well by Freundlich isotherm models and adsorption process was chemical. It is concluded that the montmorillonite-biochar composite can be used as an effective adsorbent for the removal of Cu2+ ions from aqueous solutions.

The assessment of forest site quality at early stages of stand development is very essential for scientific afforestation and forest management. In order to enhance the accuracy of the existing models, a new site quality assessment model based on Genetic Algorithm-Radial Basis Function (GA-RBF) was proposed to predict site index (stand dominant height). Data used in this study came from 980 permanent sample plots for Chinese fir (Cunninghamia lanceolata) plantations in Fujian Province, China, which were randomly divided into the training dataset (786 plots) and the testing dataset (194 plots) with a ratio of 8:2. In this paper, the GA-RBF was compared with the radial basis function (RBF) and the traditional Quantitative Theory I (QT-I) method. The results indicated that the predicted accuracy was significantly increased by using the GA-RBF model. Furthermore, we used the existing site-specific site index table of Chinese fir to test the results of the GA-RBF and the agreement was 73.2%. Therefore, we recommend the GA-RBF for assessing site quality of afforestation land.

Recycling of organic waste with enormous nutrients gives soil fertility when added to the soil and reduce the usage of chemical fertilizers. Vermicomposting process of recycling the bio-organic waste by earthworms contains efficient nutrients with low levels of toxic contents. In the present study, banana leaves waste was mixed with cow dung in different ratios. The earthworm Eudrillus euginea was later added to the compost. Total organic matter (TOM), total organic carbon (TOC), pH, EC, total alkalinity and phosphorus were analysed and compared for different ratios of vermicompost at different day intervals. Microorganisms present in vermicompost were isolated and analysed for their enzymatic activities. Compost maturity was also observed by FTIR application. Results showed that the vermicompost quality was improved with positive catalase and protease enzymatic activity. FTIR analysis showed the proper maturation of vermicompost with reduced complex structures such as aromatic compounds, polysaccharides and polypeptides. It was concluded that composting of organic wastes by vermicomposting promote humification, increased microbial activity and enzyme production, which in turn increase the aggregate stability of soil particles resulting in better aeration with pollutionfree technique.

To study the characteristic behaviour of NO2 is quite necessary. Nitrogen dioxide is a major pollutant in the atmosphere, being a precursor to acid rain, photochemical smog, and ozone accumulation. Measurements of NO2 data over a period of one year (October 2014-September 2015) have been used to evaluate the NO2 concentration levels. The frequency distribution of NO2 reveals that out of the total 8760 data points, about 86% of NO2 lies between 5 ppb and 20 ppb. The lowest distribution is found in the range of 0-5 ppb, while the highest lies in the range of 10-15 ppb. The NO2 measurement level has been examined on a diurnal and seasonal scale. The diurnal scale of NO2 shows lesser values during daytime and higher values during night hours. The NO2 concentration levels are high in summer and minimum in the north-east monsoon. The daytime and night-time NO2 concentration pattern is found to be similar to the global scenario. It is observed that the NO2 concentrations in the study area are not high enough to pose health problems. The observed NO2 concentration levels at the study area are well within the National Ambient Air Quality standard for the entire period of study.

A survey of environmental gamma radiation levels is attempted in the geographical site under construction to establish a petrochemical industry. The knowledge of natural background radiation is one of the significant steps in establishing the chemical industry. Some chemical operations such as chemical refinement may sometimes influence the natural radiation levels. The attempt of measurement of natural background gamma levels in the present paper is to establish the baseline data, which on further measurements will be useful to analyse the changes in natural background radiation levels at the time of operation of a chemical plant. The present investigation shows the activity levels of gamma radiation in the site under construction at 65 locations. The gamma levels are found to vary from 1459 μGyy-1 to 2765 μGyy-1 with the average of 2141±304 μGyy-1. It is to be noted from the study that the average gamma radiation levels at two sample locations, cement mixing point (2307 μGyy-1) and stone crushing point (2529 μGyy-1) have been elevated. The elevated radiation levels at the two sample locations can be attributed to the radioactive dust emitted in the process of crushing stones and cement mixing.

Sponge gourd (Luffa aegyptiaca) was grown in pots with and without inoculation with two arbuscular mycorrhizal (AM) fungi, viz., Glomus macrocarpum and Glomus monosporum singly and in combination. Seven-day-old plants were treated with 18.9 μg Cd g⁻¹ soil and 155.4 μg Ni g⁻¹ soil alone and in combination. At 90 days old stage, dry weight of root, shoot, and fruit; uptake of heavy metals in root, stem, leaves, and fruits; percent mycorrhizal root colonization; and spore number in the root zone were determined. When applied singly, the uptake of Cd and Ni in host plants was enhanced more effectively by G. monosporum than G. macrocarpum. The larger proportion of Cd uptake in uninoculated host was retained in the roots but in inoculated plants (with both Glomus sp.), major amounts of the Cd were translocated to the above ground parts including fruits. The leaves were the main sinks of Ni in inoculated plants. The overall tissue burden of both heavy metals in the host was enhanced relatively more effectively on association with G. monosporum as compared with G. macrocarpum. The uptake of Cd was relatively higher in plants treated with both the metals and both the AM fungi. Despite the relatively higher uptake of both the heavy metals in inoculated plants, the host dry weight was significantly higher compared with uninoculated plants. The percent mycorrhizal root colonization of the host by both AM fungi was higher in plants grown without either of the heavy metals. The combined application of both the heavy metals reduced the spore density in the root zone soil of host. The results show that the AM fungi enhanced the uptake of Cd and Ni by the host but alleviated the toxicity by promoting plant growth.

The anode configuration determined the performance of power generation and contaminant removal in microbial fuel cell (MFC). In this study, double anodes were constructed along an up-flow MFC for mitigating the suppression of refractory organic azo dye Reactive Brilliant Red X-3B and increasing the power output. Results revealed that high concentration of X-3B suppressed the power generation of MFC. The maximum power density decreased from 0.413 to 0.161 W/m³, and the inner resistance rose from 448 to 698 Ω. However, double anodes weakened the suppression of X-3B to the current generation. Compared with single anode, the attenuation of MFC current decreased from 48 to 40%. Meanwhile, the X-3B removal efficiency in double-anode MFC was 19.81% higher compared with a single-anode condition when the X-3B was 1000 mg/L. The degradation pathway analysis indicated that aromatic amines formation and further oxidation were achieved sequentially in the MFC. Furthermore, microbial communities in the lower and upper anodes were analyzed, revealing that the microorganisms in the lower anode were more inclined to degrade the pollutant, whereas those in the upper anode were more inclined to generate electricity. This double-anode structure showed the potential for large concentration range of azo dye removal and the current recovery in real textile wastewater.

Exposure to polycyclic aromatic hydrocarbons (PAHs) during pregnancy may pose adverse health risk to both the mothers and babies. In the present study, 188 pregnant women of different trimesters were recruited in Guangzhou, south China, and nine hydroxyl PAHs (OH-PAHs) and a biomarker of DNA oxidative damage, 8-hydroxy-2′-deoxyguanosine (8-OHdG), were determined in their urine samples. All OH-PAHs except for 4-hydroxyphenanthrene and 6-hydroxychrysene were found in > 90% samples, with total concentration in the range of 0.52 to 42.9 μg/g creatinine. In general, concentration levels of OH-PAHs in pregnant women were lower than those in general population in the same research area but with higher levels in working women than in housewives. The mean daily intakes of PAHs from dietary estimated by urinary OH-PAHs were 0.021, 0.004, 0.047, and 0.030 μg/kg_bw/day for naphthalene, fluorene, phenanthrene, and pyrene, respectively, which were much lower than the reference doses (20, 30, and 40 μg/kg_bw/day for naphthalene, pyrene, and fluorene, respectively) derived from chronic oral exposure data by the United States Environmental Protection Agency. The low exposure levels of PAHs may be attributed to the traditional dietary taboo of Chinese pregnant women, which is to minimize the consumption of “toxic” food. The concentrations of 8-OHdG (4.67–49.4 μg/g creatinine) were significantly positively correlated with concentrations of several OH-PAHs, such as metabolites of naphthalene, fluorene, and phenanthrene (r = 0.3–0.6). In addition, the concentrations of 8-OHdG were higher in working women than in housewives when exposed to the same levels of PAHs, partly indicating the possible relation between work-related pressure for working women and the oxidative stress.

Extensive use of aluminum (Al) in industry, cooking utensils, and wrapping or freezing the food items, due to its cheapness and abundance in the environment, has become a major concern. Growing evidence supports that environmental pollutant Al promotes the aggregation of amyloid beta (Aβ) in the brain, which is the main pathological marker of Alzheimer’s disease (AD). Further, AD- and Al-induced neurotoxic effects are more common among women following reproductive senescence due to decline in estrogen. Though clinically Ginkgo biloba extract (GBE) has been exploited as a memory enhancer, its role in Al-induced neurotoxicity in reproductive senescent female rats needs to be evaluated. Animals were exposed to intraperitoneal dose (10 mg/kg b.wt) of Al and oral dose (100 mg/kg b.wt.) of GBE daily for 6 weeks. A significant decline in the Al-induced Aβ aggregates was observed in hippocampal and cortical regions of the brain with GBE supplementation, as confirmed by thioflavin (ThT) and Congo red staining. GBE administration significantly decreased the reactive oxygen species, lipid peroxidation, nitric oxide, and citrulline levels in comparison to Al-treated rats. On the contrary, a significant increase in the reduced glutathione, GSH/GSSG ratio as well as in the activities of antioxidant enzymes was observed with GBE administration. Based on the above results, GBE prevented the neuronal loss in the hippocampus and cortex, hence caused significant improvement in the learning and memory of the animals in terms of AChE activity, serotonin levels, Morris water maze, and active and passive avoidance tests. In conclusion, GBE has alleviated the behavioral, biochemical, and histopathological alterations due to Al toxicity in rats. However, molecular studies are going on to better understand the mechanism of GBE protection against the environmental toxicant Al exposure. Graphical abstract .