The Phromhot Canal is the only natural water source for consumption and agriculture the Sa Kaeo special economic zone, Thailand. At present, the Phromhot Canal is facing a serious problem with water quality. Our study carried out to analyze and assess the pollution carrying capacity of the natural water resource. The sampling sites were examined 7 stations cut across the downstream areas. All these stations were served as the control station to represent the actual condition of the Phromhot Canal. The results indicated that the water quality of the Phromhot Canal after flowing through the Aranyaprathet Municipality's wastewater treatment plant (AM's-WWTP) was severely contaminated. Effluents from the AM's-WWTP does not meet the effluent quality standard of the Ministry of Natural Resources and Environment, Thailand. In addition, it can flow into the water body up to 6,439.55 m3/day. The maximum amount of a pollutant (in terms of BOD loading) allowed to enter a water body of the Phromhot Canal should be ≤ 0.08 kgBOD/day (dry period) and 16.52 kgBOD/day (wet period). While the Phromhot Canal has to carry BOD loading up to 51.12 kgBOD/day. For this reason, the Phromhot Canal at after flowing through the WWTP was unable to the pollution carrying capacity. From the field survey, the AM's-WWTP is not suitable for wastewater treatment, which has a capacity of 923.93 m3/day. Therefore, it is necessary to strictly control the drainage of the wastewater from the Aranyaprathet Municipality's wastewater treatment system, both quantitative and geographic.

Macrophytes are creatures with low versatility and cannot stay away from any mix of streamflow, nutrient accessibility, and other physical and chemical attributes that impact their survival in the aquatic system. Sampling for macrophytes in Chanchaga River was conducted monthly for a 6-month period (May - October 2019). Sampling stations were selected at approximately equal distance along the streamline, the aquatic vegetation were surveyed, and some environmental variables were analysed using standard methods. Results obtained indicated that temperature ranged from 24.6-28.4°C; pH 6.4 -9.7; Electrical conductivity 28.0-79.0μS cm-1; Total dissolved solids 16-75 mg L-1; Dissolved oxygen(DO) 1.3-5.2 mg L-1; Nitrate 0.217-0.654 mg L-1; Phosphate 0.084-0.211 mg L-1; Biological oxygen demand (BOD) 0.89-5.4 mg L-1 and total alkalinity 8.00-11.00 mgL-1 for the study period. A total of eleven (11) macrophyte species belonging to ten genera and eight families were identified during the entire study. Variations in terms of families showed that Araliaceae was the most abundant followed by Poaceae, while Cyperaceae had more species throughout the study period. The high frequency of Araliaceae, Cyperaceae, and Poaceae families suggests that the environmental characteristics favour these species. We propose the use of Cyperus digitatus, Cyperus papyrus and Mimosa spp. as macrophytes indicators of organic pollution in Chanchaga River.

This study analyzed the potential use of Mahagoni wood charcoal (MWC) and Mahagoni bark charcoal (MBC) as biosorbent for reactive red 120 (RR 120) dye removal from aqueous solutions. The effect of different operating parameters such as contact time (1–210 min), pH (3–11), adsorbent dose (1–20 g/L), and initial RR 120 concentration (5–70 mg/L) on adsorption processes was studied under batch adsorption experiments. The maximum removal of RR 120 by MWC (78%) and MBC (88%) was achieved when the optimum conditions were initial RR 120 concentration (5 mg/L), pH (3), adsorbents dose (10 g/L) and equilibrium contact time (150 min). The RR 120 adsorption data of MWC and MBC were better described by the Langmuir and Freundlich isotherm models, respectively. The MWC and MBC showed maximum adsorption capacities of 3.806 and 5.402 mg/g, respectively. Kinetic adsorption data of all adsorbents (MWC and MBC) followed the pseudo-second-order model and this adsorption process was controlled by chemisorption with multi-step diffusion. A lower desorption rate advocated that both strong and weak binding forces could exist between RR 120 molecules and adsorbents. The study results revealed that the utilization of either MWC and or MBC as an adsorbent for treating RR 120 is effective and environmentally friendly.

In this study natural bentonite (NB) and acid-thermal co-modified bentonite (MB) were utilized as adsorbents for the removal of Thymol Blue (TB) from aqueous solution. The batch adsorption experiments were conducted under different experimental conditions. The artificial neural network (ANN) and adaptive neuro fuzzy inference systems (ANFIS) were applied to estimate removal percentage (%) of TB. Mean squared error (MSE), root mean square error (RMSE) and coefficient of determination (R2) values were used to evaluate the results. In addition, the experimental data were fitted isotherm models (Langmuir, Freundlich and Temkin) and kinetic models (pseudo first order (PFO), pseudo second order (PSO) and intra-particle diffusion (IPD)). The adsorption of TB on both the NB and MB followed well the PSO kinetic model, and was best suited Langmuir isotherm model. When the temperature was increased from 298 K to 323 K for 20 mg/L of TB initial concentration, the removal percentage of TB onto the NB and MB increased from 74.91% to 84.07% and 81.19% to 93.12%, respectively. This results were confirmed by the positive ΔH° values indicated that the removal process was endothermic for both the NB and MB. The maximum adsorption capacity was found as 48.7805 mg/g and 117.6471 mg/g for the NB and MB, respectively (at 323 K). As a result, with high surface area and adsorption capacity, the MB is a great candidate for TB dye removal from wastewater, and the ANFIS model is better than the ANN model at estimating the removal percentage of the dye.

Climate change could be exacerbated by waste disposal problems, which destroy the ecosystem. Utilizing waste byproducts in creating eco-friendlier geopolymer concrete was hypothesised to be suitable and sustainable to overcome the negative impacts of wastes. The researchers had missed out on developing an alternate binder due to increasing demand for fly ash, high alkaline activators, and higher curing temperatures. This research used waste wood ash that is readily accessible in local restaurants and has an inherent potassium constituent. It has decided to replace the fly ash with waste wood ash obtained through nearby restaurants at intervals of 10 percent. The fresh and mechanical features have been discovered over long curing periods to assess the impact of waste wood ash. SEM and XRD have been used for characterising the microstructure of selected geopolymer mixes. In terms of setting properties and all mechanical parameters, replacing 30 percent waste wood ash produced enhanced results. The optimised mix could be used in geopolymer to replace fly ash and reduce the cost of alkaline activators while also reducing ecosystem damage.

Polycyclic Aromatic Hydrocarbon profile of Kpite oil spill impacted site in Rivers state, Nigeria was evaluated to determine the level of contamination of the soil. Four composite oil impacted soil samples were collected at different depths; surface (0-15cm) and subsurface (15-30cm) after a field reconnaissance. Extraction of the oil was carried out on the soil samples and the Polycyclic Aromatic Hydrocarbons were quantified using the Gas Chromatography- flame ionization detector. Results showed that Naphthalene was the most abundant in the range of 0.25 to 1.49 mg kg-1. Fluoranthene followed closely with concentrations in the range of 0.01 to 1.28 mg kg-1. PAHs like Benzo (k) fluoranthene, Benzo (e) pyrene, Dibenzo (a, h)anthracene, Indeno (1, 2, 3-cd) pyrene and Benzo (g, h, i) showed low concentrations of less than 0.01 indicating that strong weathering had occurred. The diagnostic ratios such as Phenanthrene/Anthracene (Phen/Anth), Benzo (a) anthracene Chrysene ((BaA)/Chry) and Fluoranthene/Pyrene (Flth/Py) and sum of chrysene/Phenanthrene ΣChry/ΣPhen were calculated and used to unravel the source of hydrocarbons. Results showed ratios of Flth/Py >1.0 and Phen/Anth ranges from 1.19 to 2.03 (< 10) which denote contamination sources, implying that the hydrocarbon sources are not just petrogenic but rather may due to contamination sources of combustion processes or the area was exposed to bush burning.

The heavy metal pollution in soil caused by mining area development is a global problem. In order to screen the ecological restoration plants of copper silver tailings in arid and high saline alkali areas, and evaluate their economic value, nine kinds of plants naturally growing in the northwest copper silver tailings pond were selected, the enrichment and transfer characteristics of eight heavy metals by this plants was analyzed, and potential health risks for humans of plants were focused. The results showed that the heavy metals such as Cd, As, Cu, Hg and Ag are all from the open-air accumulation of tailings slag. Translocation factors of Cu, Ni and Cr by C. tragacanthoides are 2.1205, 53.1548 and 13.7622, bioconcentration factor of Cu, Ni and Cr by C. tragacanthoides are 1.8888, 7.1979, 7.4653, C. tragacanthoides is the hyperaccumulator for Cu, Ni and Cr. Hazard index in roots of S. collina, C. virgata and A. splendens to adults is more than 1, it has a potential non-cancer effects for more than half of adults, and for over 86.23% of children. Ag, Cr and As contribute the best to HI, and the cumulative contribution rate of the three elements can reach 85.59% to 96.39%. It is necessary to improve the treatment of tail slag to reduce environmental pollution, C. tragacanthoides can be considered as heavy metal remediation plants in arid and high saline copper tailing areas, but there is no medicinal value for these plants as ecological reconstruction in tailings area.

Increase in advanced electronic technology leads to environmental issues related with its disposal. Electronic waste i.e., video card and random access memory were used for studying extraction of precious metals using Paenibacillus sp. Metal contaminated soil was used for the isolation of exopolysaccharide producing strains. The isolate was identified as Paenibacillus sp. based on morphological, biochemical tests and 16S rRNA sequencing. Metal content analysis of soil and e-waste was carried out using X-ray Fluorescence spectroscopy. The vanadium element was more in the soil sample which was 0.487 mg/g and in electronic waste sample copper content was more which was 250 mg/g. Paenibacillus sp. produced capsule which was observed under bright, dark field and phase contrast microscope. Scanning electron microscopy was done for the study of morphological changes of exopolysaccharide producing Paenibacillus sp. in chitin broth and on chitin agar medium with and without e-waste. The Fourier Transform Infrared Spectroscopy analysis of exopolysaccharide produced by Paenibacillus sp. grown on chitin agar and chitin agar with e-waste showed presence of different functional groups. The one step and two step bioleaching experiments were carried out for testing efficacy of biomass on metal leaching. Paenibacillus sp. showed its potential for the extraction of precious metals viz., gold, silver and copper from electronic waste. Paenibacillus sp. recovered gold (0.001%), cadmium (45%), copper (50%), iron (46%), manganese (88%), palladium (56.9%) and zinc (87.12%) by two step fermentation. The study is useful for the bioleaching of precious metals from electronic waste.

This paper explores long-run and causal effects of financial development, real growth, urbanization, gross capital formation and energy consumption on CO2 emissions in Thailand by utilizing recent econometric techniques. The study employs ARDL technique to examine the long and short run interconnection between CO2 emissions and the regressors. Furthermore, we employ the FMOLS, DOLS and CCR as a robustness check to the ARDL long-run estimator. The study use time-series data spanning from 1971 to 2016. The study also utilizes the wavelet coherence technique to collect information on the association and causal interrelationship among these economic variables at different frequencies and timeframes in Thailand. The study objectives are structured to answer the following questions: (a) does the selected macroeconomic indicators impact CO2 emissions in Thailand? (b) if so, why? Findings reveal; (i) Negative and insignificant link between CO2 emissions and urbanization. (ii) GDP growth affects CO2 emissions positively. (iii) The interconnection between CO2 emissions and energy usage is positive. (iv) Gross capital formation impact CO2 emissions positively. (v) Positive interconnection exists between financial development and CO2 emissions in Thailand. Additionally, the wavelet coherence result provides a supportive evidence for the ARDL long run result. Based on these findings, policy directions were suggested.

Tree rings have been used to reconstruct past climates as well as to assess the effects of recent climatic and environmental changes on tree growth. Industrial emission is one of the major sources of pollutants in the atmosphere. This study determined heavy metals pollution chronologies from industrial emissions in the atmosphere of the Tema industrial area of Ghana using tree-rings as bio-indicators. Swietenia mahagoni (Mahogany) tree was bored and the rings counted and age determined to be 50 years spanning from 1968 to 2018. Tree growth rates were calculated through ring width measurements and related to annual precipitation data spanning over the sampling period. It was observed that wet seasons correlate with high growth rates of trees while low precipitation seasons correspond to low or no growth rate of trees. Energy Dispersive X-ray fluorescence (EDXRF) was used to investigate the presence and concentration of the four heavy metals (Cu, Zn, Fe and Pb). Concentration of Cu, Zn, Fe and Pb ranged from (1.92—6.70 mg/kg), (5.37 – 13.9 mg/kg), (0.10 – 0.36 mg/kg) and (12.13—90.13 mg/kg), respectively. Surprisingly, an increasing trend in concentration was observed for Zn and Cu with levels higher than the WHO guideline for heavy metals in the plant.