Effectiveness of macroalgae was investigated for enhancing wastewater treatment processes. Bioremediation using macroalgae could remove nitrate and phosphate contaminants in the water where algae assimilate nitrogen and phosphorus and convert them to biomass. This study evaluates the effects of high nitrate concentration on the kinetics of cell growth during nitrate and phosphate removal by a macroalga Cladophora glomerata. The algal growth and nitrate removal from media containing initial nitrate concentrations of 5mg/L to 400 mg/L were monitored in batch growth, whereas control media has no additional nitrate. Light exposure was kept for 12 and 20 hours. The purpose of this research was to find out the effect of various nitrate concentrations on nitrate and phosphate removal with macroalgal growth. Maximum growth kinetic reaches ?=0.075/day in 20 hours light exposure with 100 mg/L initial nitrate concentration. Nitrate and phosphate reach about 90% removal rates on the fifth day. Nitrate concentration was not significantly affected by biomass growth (Pearson correlation: 0.295). But, phosphate concentration has a moderate correlation with macroalgae biomass (Pearson correlation: 0.533).

In recent years, the issue of environmental pollution caused by the manufacturing industry has been widely criticized. To explore the relationship between capital enrichment and environmental pollution, the mediating effect model was constructed by using the panel data of 28 sub-sectors of China’s manufacturing industry from 2011 to 2017. Results show that the phenomenon of capital enrichment is mainly concentrated in industries with high-profit margins, intensive technology, national policy support, and resource or national monopolistic positions. Both capital enrichment and innovation capability have a promotion effect on inhibiting environmental pollution, but with the decline of innovation capability, the effect of capital enrichment on pollution weakens. Innovation capability plays a mediating role, which leads to the mechanism of capital enrichment ? innovation capability ? environmental pollution. The impact of capital enrichment on environmental pollution under different levels of innovation capability is heterogeneous, and the effect is stronger in high-tech industries.

The study considered the level, sources and extent of trace and rare earth elements (REE) contamination in Agbangudu stream sediments in Ekiti State, Southwestern Nigeria. The samples were analysed with Laser Ablation Inductively Coupled Plasma Spectrometer (LA-ICP-MS). The trace and rare earth elements’ concentration ranged from 0.50 (Mo) to 750 (Ba) and 0.16 (Lu) to 175 (Ce) ppm respectively. The results revealed that the sediments are not that enriched in REEs. The Pollution Load Index (PLI) indicates baseline levels of the metals. The geochemical index (Igeo) of the elements revealed uncontaminated to moderately contaminated, except for Cs and Ta with strongly to extremely contaminated status. The Average Shale Value (AVS) and the Upper Continental Crust (UCC) normalized REE distribution patterns of the sediments. To establish the relationship between the metals, Principal Component Analysis (PCA) and Clusters Analysis (CA) were used as classification techniques. Despite the common occurrences of the elements, their overall patterns were much different as revealed by the cluster analysis.

The status quo that the shortage of water resources in North China and the arbitrary discharge of sewage in rural areas have led to the deterioration of water environment, which not only aggravates the contradiction between supply and demand of regional water resources but also brings harm to people’s life and health. How to properly discharge sewage according to the actual situation in rural areas is a question that needs to be answered urgently. The method adopted in this paper is to build a constructed wetland with low cost and simple operation and maintenance in the study area, and purify the water quality through parallel + multi-stage cascade surface flow constructed wetland system. The results show that the purification effect of the wetland system is acceptable, and the removal rate of each index shows a decreasing trend with time. The larger the area is, and the more plant species there are, the better the removal effect will be. The trend of concentration change along the water flow path of each index is also gradually decreasing, and the decline in the early stage is larger. The method of standard index evaluation is adopted to evaluate water quality purification effect of the wetland system, and all indexes reach the standard. In accordance with the Surface Water Environment Quality Standard (GB3838-2002), after wetland purification, the water quality indexes of COD, TP, NH3-N and DO all reach Class IV water quality standard, and BOD5 reaches Class II water quality standard. The wetland system effectively reduces the impact of arbitrary sewage discharge on the water environment in rural areas and achieved water quality purification and ecological restoration. The quality of the living environment of local residents is improved. The beautiful environment also promotes people’s awareness of protecting wetland ecological environment.

Jiagou district, located in Northern Anhui Province, China, has been taken as an agriculture demonstration base for several decades, but limited hydrochemical work has been conducted on the water resources. The objective of this research was to understand the controlling processes of hydrochemical evolution and the water quality for drinking and irrigation. Twenty-seven samples of surface water and groundwater have been collected and analysed for major ions. Although the values physicochemical parameters are subjected of spatial fluctuation in different water resources, calcium and bicarbonate is still the dominant ion in the cations and anions, respectively. The values of all the parameters are within the WHO maximum permissible limit for inhabitant drinking. The predominant water type is Ca-Mg-HCO3 and Ca-HCO3. The hydrochemical methods (Gibbs diagram, Mg/Na and HCO3/Na versus Ca/Na diagram and ion ratios) suggest that rock-water interactions furnish the dominant major ion sources of the samples. Carbonate dissolution, silicate weathering and ion exchange have the predominant contribution to the origin of chemical solutes, as well as a slight function of halite dissolution. The USSL and Wilcox diagram reveal that all the samples have low salinity and low sodium water. It is of good quality suitable for irrigation, and it can be used for irrigation of most crops on most soils with less negative impacts.

Dyes from industrial wastewaters represent one of the most hazardous pollutants as they are not effectively biodegradable. The present work is focused to study the novel properties of keratin-polyamide blend nanofibrous filtration membranes for treating wastewaters containing dye. Keratin protein was extracted from goat hair, a tannery waste through sulphitolysis process. The extracted keratin was blended with polyamide to prepare a nanofibrous membrane through the electrospinning process. The fabricated pristine polyamide and keratin-altered polyamide membranes were characterized and compared for their properties. Effects of solution pH, dye concentration, membrane flux, and membrane capacity have been examined. Very fine nanofibers and enhanced porosity drive the membrane to enhanced flux and higher filtration efficiencies. At pH 2, the dye removal efficiency of the blend membranes was 100, 99, 98, 90, and 83% for 100, 200, 250, 300, and 400 ppm concentrations of dye, respectively. The keratin–polyamide blend membrane exhibited better properties in all aspects. The results of this present investigation indicate that the presence of keratin in filtration membranes is promising for dye removal from the effluents.

This study investigates the spatial influence and spillover effects of foreign direct investment (FDI) on environmental pollution (EP) by using panel spatial data in 1970–2016 for 12 selected Arab countries. It employs the STochastic Impacts by Regression on Population, Affluence, and Technology (STIRPAT) model. The spatial econometric approach is applied to examine the validity of the pollution haven hypothesis (PHH) and the pollution halo hypothesis (P-HH) (from now on, we will use the acronyms PHH and P-HH to denote the pollution haven hypothesis and pollution halo hypothesis, respectively). The Sustainable Development Goals (SDGs) are linked to the study results with a focus on cleaner production practices. The global Moran’s I, local Moran’s I, and Lagrange multiplier (LM) tests are used to ascertain the existence of spatial autocorrelation (SAR) and determine its trend. We also apply the spatial lag model (SLM), the spatial error model (SEM), and the spatial Durbin model (SDM) to achieve the study objectives. Data are analyzed by using the SDM on the basis of the results of the Wald and likelihood ratio tests. The results of the LM and global and local Moran’s I tests confirm the existence of SAR. The SDM results reveal that a slight increase in CO₂ is an influence of the FDI on EP. Findings support the existence of PHH in the Arab countries. The direct effect of the FDI is increased CO₂ and environmental degradation, and the spatial spillover effects are statistically insignificant. This study suggests a set of policies for managing and directing FDI toward clean technology-based industries and reduced CO₂ emissions. Such policies may contribute to the achievement of some SDGs and balancing economic development and environmental sustainability according to the cleaner production practice perspective in the Arab countries and other states with similar conditions.

Aquatic environments are crucial hotspots for the dissemination of antibiotic resistant microorganisms and resistance genes. Thus, the purpose of this study was to investigate the occurrence and the genetic characterization of cefotaxime-resistant (CTXᴿ) Enterobacteriaceae at a Tunisian semi-industrial pilot plant with biological treatment (WWPP) and its receiving river (Rouriche River, downstream from WWPP) located in Tunis City, during 2017–2018. We collected 105 and 15 water samples from the WWPP and the Rouriche River, respectively. Samples were screened to recover ESBL-producing Enterobacteriaceae (ESBL-E) and isolates were characterized for phenotype/genotype of antimicrobial resistance, integrons, plasmid types and molecular typing (multilocus sequence typing, MLST). Among 120 water samples, 33 and 4 contained ESBL-producing E. coli and K. pneumoniae isolates, respectively. Most isolates were multidrug resistant and produced CTX-M-15 (28 isolates), CTX-M-1 (4 isolates), CTX-M-55 (2 isolates), CTX-M-27 (one isolate), SHV-12 (one isolate) and VEB beta-lactamases (one isolate). All K. pneumoniae were CTX-M-15-positive. Four colistin-resistant isolates were found (MIC 4–8 μg/ml), but they were negative for the mcr genes tested. Class 1 integrons were detected in 21/25 trimethoprim/sulfamethoxazole-resistant isolates, and nine of them carried the gene cassette arrays: aadA2 + dfrA12 (n = 4), aadA1 + dfrA15 (n = 2), aadA5 + dfrA17 (n = 2) and aadA1/2 (n = 1). The IncP and IncFIB plasmids were found in 30 and 16 isolates, respectively. Genetic lineages detected were as follows: E. coli (ST48-ST10 Cplx, ST2499, ST906, ST2973 and ST2142); K. pneumoniae: (ST1540 and ST661). Our findings show a high rate of CTX-M-15 and high genetic diversity of ESBL-E isolates from WWPP and receiving river water.

This paper assesses the potential impact of reduced Nile water due to the construction of Grand Ethiopian Renaissance Dam (GERD) on flow and contaminant transport pattern in Ismailia Canal and its surrounding area. The groundwater/surface water system has been characterized, conceptualized, and modeled numerically and analytically, with assessing the response against this expected reduced discharge. The isotopic signature of seventeen samples helped in the identification of different recharge sources in the study area and demarcates the boundary conditions that might encounter the conceptualization of the study area. Based on the inflow/outflow components from MODFLOW under present-day conditions and reducing surface water discharge in the studied area, it was revealed that at the end of the year 2024, the contribution from the canal to the modeled groundwater system will be decreased by 6%, 8%, and 11%, by decreasing 20%, 30%, and 40% of the original canal flow according to three proposed scenarios. This reduced flow would increase the contaminate load of ¹³⁷Cs in the groundwater system by 2.5-fold than that expected in case of the non-reduced flow in Ismailia Canal at the end of the simulation (year 2038). Furthermore, the impact of surface water conditions (flow, velocity, dispersion) on ¹³⁷Cs dispersion and temporal/spatial distribution has been analyzed, revealing the side effect of GERD on Ismailia Canal, as a response to the decrement in the Nile flow.