•A comparative study investigated the treatment of textile wastewater.•The color, COD and turbidity removal was studied in anaerobic IC reactor and Fenton’s process.•Fenton’s reagent at pH 3 was ...effective for color removal and IC reactor was efficient for COD removal.•Fenton’s process without pH adjustment was better in turbidity removal.
Textile wastewater (TW) is one of the most hazardous wastewaters for the environment when discharged without any proper treatment. A comparative study was conducted to investigate the removal efficiency of color, chemical oxygen demand (COD) and turbidity from real textile industry wastewater using anaerobic IC reactor and Fenton’s process with and without pH adjustment. Color, COD and turbidity removal efficiencies have been studied for 25%, 50%, 75% and 100% textile wastewater. Results demonstrated that a maximum color removal efficiency (>92%) was recorded in Fenton’s process at pH 3 for 100% sample. However, maximum COD removal efficiency of 87% was observed in IC reactor for 100% sample. Thus, Fenton’s reagent at pH 3 was found highly effective for color removal and IC reactor observed to be efficient for COD removal. Furthermore, Fenton’s process without pH adjustment was found higher turbidity removal efficiency as compared to other treatments. Findings from this suggested that the selective treatment process could be highly promising for the decolorization of textile wastewater and can also be practically implementable.
Anaerobic digestion is the method of wastes treatment aimed at a reduction of their hazardous effects on the biosphere. The mutualistic behavior of various anaerobic microorganisms results in the ...decomposition of complex organic substances into simple, chemically stabilized compounds, mainly methane and CO2. The conversions of complex organic compounds to CH4 and CO2 are possible due to the cooperation of four different groups of microorganisms, that is, fermentative, syntrophic, acetogenic, and methanogenic bacteria. Microbes adopt various pathways to evade from the unfavorable conditions in the anaerobic digester like competition between sulfate reducing bacteria (SRB) and methane forming bacteria for the same substrate. Methanosarcina are able to use both acetoclastic and hydrogenotrophic pathways for methane production. This review highlights the cellulosic microorganisms, structure of cellulose, inoculum to substrate ratio, and source of inoculum and its effect on methanogenesis. The molecular techniques such as DGGE (denaturing gradient gel electrophoresis) utilized for dynamic changes in microbial communities and FISH (fluorescent in situ hybridization) that deal with taxonomy and interaction and distribution of tropic groups used are also discussed.
This study is based on self-reported information collected from selected farmers of Vehari District, Punjab, Pakistan, to determine their technical knowledge and awareness about pesticide use and ...associated environmental and health risks. Moreover, soil contamination by routinely used persistent organochlorine pesticide, endosulfan, was also evaluated. Survey data revealed very low literacy rate (on an average 9th grade education) and technical knowledge (almost missing) of the farmers in Vehari District. The farmers are unable to fully read and understand the instructions about the use of pesticide marked on the containers. They are not fully aware of pesticide persistence and toxicity (73%), unable to identify cotton pests and diseases (86%), and do not know which crop to grow in cotton adjacent fields (100%). Data also revealed that the farmers (100%) do not follow safety measure during pesticide application and are unaware of pesticide toxicity symptoms in human as well as the basic first-aid practices (89%).
Poor literacy rate and lack of technical knowledge of farmers in Vehari regarding pesticide use and handling are posing serious environmental and health risks among the local inhabitants, particularly among farmers. Soil analysis results showed that concentration of α- and β-endosulfan ranged from 0–14 to 0–14.64 μg/mg, respectively. Principal component analysis showed that soil organic matter is the key soil parameter controlling the occurrence and fate of endosulfan under sandy loam soil conditions of Vehari District. There is a serious need of improving technical and environmental knowledge of farmer about pesticide risks on human health in the studied area, in particular, and the entire country in general. Findings are of great use for policymaking in Pakistan to minimize pesticide risks in Pakistan.
Microalgal biomass provides a renewable source of biofuels and other green products. However, in order to realize economically viable microalgal biorefinery, strategic identification and utilization ...of suitable microalgal feedstock is fundamental. Here, a multi-step suboptimal screening strategy was used to target promising microalgae strains from selected freshwaters of the study area. The resulting strains were found to be affiliated to seven closely-related genera of the family Scenedesmaceae, as revealed by both morphologic and molecular characterization. Following initial screening under upper psychrophilic to optimum mesophilic (irregular temperature of 14.1 to 35.9°C) cultivation conditions, superior strains were chosen for further studies. Further cultivation of the selected strains under moderate to extreme mesophilic cultivation conditions (irregular temperature of 25.7 to 42.2°C), yielded up to 74.12 mgL-1day-1, 19.96 mgL-1day-1, 48.56%, 3.34 μg/mL and 1.20 μg/mL, for biomass productivity, lipid productivity, carbohydrate content, pigments content and carotenoids content respectively. These performances were deemed promising compared with some previous, optimum conditions-based reports. Interestingly, the fatty acids profile and the high carotenoids content of the studied strains revealed possible tolerance to the stress caused by the changing suboptimal cultivation conditions. Overall, strains AY1, CM6, LY2 and KL10 were exceptional and may present sustainable, promising feedstock for utilization in large-scale generation of green products, including biodiesel, bioethanol, pigments and dietary supplements. The findings of this study, which exposed promising, eurythermal strains, would expand the current knowledge on the search for promising microalgae strains capable of performing under the largely uncontrolled large-scale cultivation settings.
Textile dyes and microbial contamination of surface water bodies have been recognized as emerging quality concerns around the globe. The simultaneous resolve of such impurities can pave the route for ...an amicable technological solution. This study reports the photocatalytic performance and the biocidal potential of nitrogen-doped TiO2 against reactive black 5 (RB5), a double azo dye and E. coli. Molecular docking was performed to identify and quantify the interactions of the TiO2 with β-lactamase enzyme and to predict the biocidal mechanism. The sol-gel technique was employed for the synthesis of different mol% nitrogen-doped TiO2. The synthesized photocatalysts were characterized using thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Brunauer–Emmett–Teller (BET) and diffuse reflectance spectroscopy (DRS). The effects of different synthesis and reaction parameters were studied. RB5 dye degradation was monitored by tracking shifts in the absorption spectrum and percent chemical oxygen demand (COD) removal. The best nanomaterial depicted 5.57 nm crystallite size, 49.54 m2 g−1 specific surface area, 11–40 nm particle size with spherical morphologies, and uniform distribution. The RB5 decolorization data fits well with the pseudo-first-order kinetic model, and the maximum monolayer coverage capacity for the Langmuir adsorption model was found to be 40 mg g−1 with Kads of 0.113 mg−1. The LH model yielded a higher coefficient KC (1.15 mg L−1 h−1) compared to the adsorption constant KLH (0.3084 L mg−1). 90% COD removal was achieved in 60 min of irradiation, confirmed by the disappearance of spectral peaks. The best-optimized photocatalysts showed a noticeable biocidal potential against human pathogenic strain E. coli in 150 min. The biocidal mechanism of best-optimized photocatalyst was predicted by molecular docking simulation against E. coli β-lactamase enzyme. The docking score (−7.6 kcal mol−1) and the binding interaction with the active site residues (Lys315, Thr316, and Glu272) of β-lactamase further confirmed that inhibition of β-lactamase could be a most probable mechanism of biocidal activity.
Drinking water quality is a major problem in Pakistan, especially in the Abbottabad region of Pakistan. The main objective of this study was to use a Principal Component Analysis (PCA) and integrated ...Geographic Information System (GIS)-based statistical model to estimate the spatial distribution of exceedance levels of groundwater quality parameters and related health risks for two union councils (Mirpur and Jhangi) located in Abbottabad, Pakistan. A field survey was conducted, and samples were collected from 41 sites to analyze the groundwater quality parameters. The data collection includes the data for 15 water quality parameters. The Global Positioning System (GPS) Essentials application was used to obtain the geographical coordinates of sampling locations in the study area. The GPS Essentials is an android-based GPS application commonly used for collection of geographic coordinates. After sampling, the laboratory analyses were performed to evaluate groundwater quality parameters. PCA was applied to the results, and the exceedance values were calculated by subtracting them from the World Health Organization (WHO) standard parameter values. The nine groundwater quality parameters such as Arsenic (As), Lead (Pb), Mercury (Hg), Cadmium (Cd), Iron (Fe), Dissolved Oxygen (DO), Electrical Conductivity (EC), Total Dissolved Solids (TDS), and Colony Forming Unit (CFU) exceeded the WHO threshold. The highly exceeded parameters, i.e., As, Pb, Hg, Cd, and CFU, were selected for GIS-based modeling. The Inverse Distance Weighting (IDW) technique was used to model the exceedance values. The PCA produced five Principal Components (PCs) with a cumulative variance of 76%. PC-1 might be the indicator of health risks related to CFU, Hg, and Cd. PC-2 could be the sign of natural pollution. PC-3 might be the indicator of health risks due to As. PC-4 and PC-5 might be indicators of natural processes. GIS modeling revealed that As, Pb, Cd, CFU, and Hg exceeded levels 3, 4, and 5 in both union councils. Therefore, there could be greater risk for exposure to diseases such as cholera, typhoid, dysentery, hepatitis, giardiasis, cryptosporidiosis, and guinea worm infection. The combination of laboratory analysis with GIS and statistical techniques provided new dimensions of modeling research for analyzing groundwater and health risks.
Arsenic (As) toxicity in soil and water is an increasing menace around the globe. Its concentration both in soil and environment is due to natural and anthropogenic activities. Rising arsenic ...concentrations in groundwater is alarming due to the health risks to plants, animals, and human beings. Anthropogenic As contamination of soil may result from mining, milling, and smelting of copper, lead, zinc sulfide ores, hide tanning waste, dyes, chemical weapons, electroplating, gas exhaust, application of municipal sludge on land, combustion of fossil fuels, As additives to livestock feed, coal fly ash, and use of arsenical pesticides in agricultural sector. Phytoremediation can be viewed as biological, solar-driven, pump-and-treat system with an extensive, self-extending uptake network (the root system) that enhances the natural ecosystems for subsequent productive use. The present review presents recent scientific developments regarding phytoremediation of arsenic contaminated environments and its possible detoxification mechanisms in plants.
The outstanding characteristics of high-rate Anaerobic Bioreactors (ABR) include anaerobic microorganisms capable of aggregation, low operational and maintenance costs, energy recovery in the form of ...biogas, low energy consumption and low production of digested sludge 4-7. Lettinga and co-researchers applied ABR process for municipal wastewater treatment since the early 1980s 9-13 and reported that about 70% chemical oxygen demand (COD) removal can be achieved under warm climates 6, 14, 15. Since its inception, wider hype has been gained by this process 16, 17. ...type of effluent may be high in COD, biological oxygen demand (BOD) and coliforms 18. ...additional post-treatment strategy is mandatory for ABR-treated effluents if further use is desired 19-21. CW is a low cost or economical on-site wastewater treatment technology which is not only effective but also aesthetically pleasing. Since 1980, the utilization of the CW for the treatment of variety of wastewater has quickly become widespread.
Irrigation of agricultural fields with industrial wastewater results in the accumulation of heavy metals (HM) in soils. This situation could be harmful to animals and humans health. Therefore, this ...study investigated HM fractions in soils treated with composted cow manure and poultry litter. Before application, manures were composted with privet and Italian cypress residues at the ratio of 1:0, 1:1, and 1:2 (animal manure:plant residues). The results showed that extraction of HM fractions reduced from contaminated soils depending upon the type and ratio of composted manure applied. Heavy metal fractions in soils reduced significantly as compost application rates increased and decreased as the amount of privet and cypress wastes in the compost increased. Heavy metals were released less from the soil amended with composted poultry litter as compared to soil samples containing cow manure. Mixing of soil with manure containing cypress residues reduced heavy metal concentrations more than the composted material containing privet residues. Concentrations of HM in polluted soil varied as Pb > Cu > Zn > Ni > Cd irrespective of the extracting agent. The concentration of HM differed among fractions as residual metal > oxide associated metal > carbonate associated metal > organically bound metal > exchangeable metal. Overall treatments of manures composted with plant waste reduced the extractability of HM from soil, and this would be beneficial for limiting HM bioavailability from contaminated soils.
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