The extensive use of broad-spectrum antibiotics, of which humans and animals metabolize less than 30

Soil contamination with cadmium (Cd) poses a serious threat to wheat production by impairing soil biological health and reducing grain quality. Organic materials such as pressmud may mitigate metal-induced stress to wheat by restoring soil microbial activities, improving nutrient uptake and limiting Cd absorption from soil. In this study, a pot experiment was conducted using salt-affected sandy loam soil spiked with Cd at 0, 25 and 50 mg kg⁻1. After two weeks, pressmud was applied to soil at 0, 10 and 20 g kg⁻1, and wheat was sown. Plants were harvested at the seedling stage and at maturity to assess soil biological activity, plant antioxidants, growth, yield and grain Cd accumulation. Cadmium contamination significantly suppressed soil biological activity, reducing soil respiration by 6–19

The textile industry generates a substantial quantity of wastewater containing carcinogenic and mutagenic dyes, posing significant environmental risks. Using microalgae to remove dyes from wastewater offers an eco-friendly solution to this issue. Accordingly, this study aimed to characterize textile wastewater and evaluate the potential of Chlorella sorokiniana strain HIN-3 for dye removal. Twenty textile wastewater samples were analyzed for pH, electrical conductivity, total dissolved solids (TDS), chlorides, cadmium, lead, chromium, nickel and color. The ability of strain HIN-3 to biodegrade seven structurally distinct dyes was investigated. The effects of metals (cadmium, lead and copper), TDS (1300–5200 mg L−1) and nitrogen sources (NaNO3, NH4Cl and urea) on dye degradation were evaluated. Additionally, six dye-rich industrial effluents were treated with microalgae for dye removal, and the activities of dye-degrading enzymes were measured. Results revealed that 25

A huge volume of industrial wastewater laden with toxic heavy metals, including cadmium, lead, nickel and copper, is discharged into the environment without treatment. Pressmud, a byproduct of sugar industry, could serve as an efficient, low-cost and environment friendly amendment for the biosorptive removal of lead (Pb) from wastewater. This study aimed to assess the biosorption efficiency of pressmud in removing Pb from water. Primarily, it evaluated the biosorption potential of pressmud for Pb, and compared it with other amendments such as, citrus waste, rice straw, biochar and activated carbon. Subsequently, the biosorption of Pb by the pressmud was measured at different temperatures (20-45 °C), pH (5-10) and biosorbent doses (2-10 g L-1). The kinetics of Pb biosorption onto pressmud were studied by pseudo-first-order (PFO), pseudo-second-order (PSO) and Elovich models. The equilibrium isotherms were studied for a range of Pb concentrations (25-500 mg L-1) using Freundlich, Langmuir and Sips models. Moreover, the pressmud was characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscope (SEM) and Brunauer-Emmett-Teller (BET). The pressmud exhibited a biosorption capacity of 5.30 mg g-1 for Pb, while surpassing other biosorbents. The biosorption capacity of rice straw, biochar, and activated carbon for Pb was 4.44, 1.94, and 0.49 mg g⁻¹, respectively. The highest biosorption capacity of pressmud was observed with contact time of 4 h, biosorbent dose of 8 g L-1, temperature of 37 °C, pH 7 and Pb concentration of 500 mg L-1. The biosorption of Pb onto pressmud followed the PFO reaction with R2RMSE and SSE of 0.981, 0.0333 and 0.0067, respectively. Langmuir model best described the adsorption behavior of Pb and predicted the maximum biosorption capacity of 43.7 mg g-1. FTIR, SEM and BET depicted that the adsorption of Pb by pressmud could be attributed to the presence of various functional groups, highly porous nature and a large surface area. Thus, pressmud could be used as a highly effective biosorbent for removal of Pb from industrial wastewater prior to its discharge into the environment.

A huge volume of textile wastewater, laden with mutagenic dyes, is discharged into the environment without treatment. Among wastewater treatment strategies, biosorption is a highly effective, low cost and environment friendly process. This study aimed to evaluate the biosorption potential of non-viable biomass of Chlorella sorokiniana strain HIN-3 for various textile dyes. Firstly, the biosorption of Congo Red (direct) and Red-S3B (reactive) from water by different biosorbents was compared. Subsequently, the biosorption of seven dyes by microalgal biomass was determined. Afterward, the biosorption of dyes was measured at different temperatures (15–50°C) and biosorbent doses (0.1–2 g L−1). Biosorption kinetics were studied by pseudo-first-order (PFO), pseudo-second-order (PSO) and Elovich models. The equilibrium isotherms were studied for dye concentration of 25–500 mg L−1 using Freundlich, Langmuir and Sips models. Moreover, the microalgal biomass was characterized by fourier-transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), scanning electron microscope (SEM), Brunauer–Emmett–Teller (BET) and energy dispersive spectroscopy (EDS). The algal biomass exhibited biosorption capacities of 242 and 45 mg g−1 for Congo Red and Red-S3B, respectively, surpassing plant-based biosorbents. Additionally, the microalgal biomass effectively removed other dyes; however, its biosorption capacity for the direct type of dyes was higher. The highest biosorption capacities of algal biomass for Congo Red and Red-S3B occurred with contact time of 8 h, biosorbent dose of 2 g L−1 and temperature of 40°C. The biosorption kinetics followed the PSO in case of Congo Red and PFO in the case of Red-S3B. Langmuir and Sips models best described the adsorption behavior of both the dyes. These models predicted the maximum biosorption capacity of algal biomass for Congo Red and Red-S3B to be 303 and 301 and 55.45 and 57.89 mg g−1, respectively. FTIR, SEM and BET depicted that the adsorption of the dyes by algal biomass could be attributed to the presence of various functional groups, highly porous nature and a large surface area. Thus, microalgal biomass is a highly effective biosorbent for the treatment of textile wastewater containing dyes prior to its discharge into the environment.

Textile dying produces a huge volume of colored effluent that is used to irrigate wheat at different times from sowing to maturity. The study investigated toxicity of Reactive RedS3B (RRedS3B) to wheat at different growth stages in pressmud and farmyard manure amended and un-amended soils. Pressmud and farmyard manure were applied at 0 and 20 Mg ha−1, whereas RRedS3B was applied either at sowing (RRedS3B-I0), 1st irrigation (RRedS3B-I1) or 2nd irrigation (RRedS3B-I2). Application of RRedS3B-I0 and RRedS3B-I1 decreased plant height by 33 and 5

The usage of antibiotics is increasing rapidly over the years worldwide. For majority of the antibiotics, < 30% is metabolized in the human and animal bodies, and the rest is released into the environment. Thus, soil contamination with antibiotics through the application of municipal wastewater and veterinary manure may become a potential threat to soil microflora and crop production. A series of experiments were conducted in laboratory and rain protected wire house to assess the influence of oxytetracycline and ciprofloxacin antibiotics on microflora (dehydrogenase activity and soil respiration rate), nitrogen uptake, growth, and yield of wheat. Preliminarily, soil was spiked with a series (0, 0.25, 0.50, 1, 5, 10, and 25 mg kg−1 soil) of oxytetracycline and ciprofloxacin levels. Antibiotics were spiked into the soil separately in triplicate following completely randomized design. The soil respiration and dehydrogenase activity were measured after 7-day of spiking of antibiotics. The two subsequent plant experiments were conducted with same treatments: One was harvested 7-week after sowing and other after 23-week until agronomic maturity. The results of incubation study depicted that the application of 25 mg kg−1 oxytetracycline increased soil respiration (79%) and dehydrogenase activity (55%), whereas ciprofloxacin decreased these attributes by 11 and 20%, respectively. In accordance with these results, oxytetracycline did not exhibit any adverse effect on shoot nitrogen uptake and growth of 7-week-old wheat seedlings, whereas ciprofloxacin at 10 and 25 mg kg−1 soil proved toxic and turned the leaves albino. Compared to control, ciprofloxacin decreased shoot biomass, tillers, and nitrogen uptake by 33, 14, and 35%, respectively, at 25 mg kg−1 soil. At maturity, soil spiking with ciprofloxacin at 25 mg kg−1 soil decreased the yield by 11%. Oxytetracycline did not suppress soil respiration, dehydrogenase activity, growth, and yield of wheat, whereby ciprofloxacin was found toxic to these attributes at the higher levels.

This study examined the effect of Red-S3B textile dye on soil microbial activities, uptake of the dye by wheat plants and growth on the dye-contaminated soil. Moreover, pressmud (PM) application was investigated for its alleviative effect on wheat yield and dye uptake by plants. Preliminarily, soil was spiked with a wide concentration range (0, 100, 250, 500, 750 and 1000 mg kg-1 soil) of Red-S3B dye and wheat was grown for 42-days. The dye did not suppress the activities of soil enzymes and growth of wheat seedlings at 100 mg kg-1; however, beyond this level the dye had a linear negative effect on these attributes. With 1000 mg dye kg-1 soil, wheat seedling biomass, viable microbial count, soil respiration, dehydrogenase, phosphatase, and urease activities decreased by 84%, 33%, 45%, 69%, 24%, and 11%, respectively as compared to uncontaminated soil. Moreover, phosphorus and potassium content in wheat shoot decreased, while the nitrogen content increased in Red-S3B contaminated soil. In the subsequent pot experiment, PM application (12.5 g kg-1 soil) was assessed to alleviate the adverse effect of moderately toxic level of Red-S3B dye (500 mg kg-1 soil) on wheat growth and yield. Root and straw biomass, and grain yield of wheat decreased by 13, 19 and 12%, respectively in Red-S3B contaminated soil as compared to uncontaminated soil. However, PM application to dye-contaminated soil retrieved the dye-induced reduction in root and straw biomass and grain yield to become statistically (p ≤ 0.05) at par with control plants. The color of Red-S3B was clearly visible in spikes depicting that plants absorbed Red-S3B but probably could not metabolize it. Amending the dye-contaminated soil with PM decreased Red-S3B content in awns from 78 to 37 mg kg-1. Hence, it is concluded that Red-S3B textile dye is highly toxic to soil microbes and wheat plants at levels exceeding 100 mg kg-1 soil. Soil application of PM alleviates the adverse effect of Red-S3B dye on wheat growth through reducing its uptake by plants.

Organic amendments improve the soil quality and plant productivity as well as help in the establishment of introduced bacteria. The present study was conducted to evaluate the interactive impact of organic amendments and plant growth promoting rhizobacteria strain Alcaligenes sp. AZ9 to improve maize productivity and soil quality. organic amendments including rock phosphate enriched compost (RPEC), biochar, and humic acid were applied in soil along with and without Alcaligenes sp. AZ9. The results revealed that the sole application of organic amendments along with Alcaligenes sp. AZ9 showed increase in growth and grain yield of maize. However, a combined application of organic amendments (RPEC, biochar, and humic acid) along with Alcaligenes sp. AZ9 showed maximum increase in plant height up to 14%, shoot dry biomass up to 30%, 1000-grains weight up to 10%, grain yield up to 31%, stover yield up to 34%, and potassium (K) concentration in grains up to 12% as compared to absolute control. The increase in nitrogen (N) and phosphorus (P) concentration in grains was non-significant over control. This treatment also improved soil biological attributes in terms of the bacterial population up to 60%, microbial biomass carbon up to 22%, soil organic carbon up to 29%, and saturation percentage of soil up to 14% as compared to control. It can be concluded that the application of organic amendments improved establishment of introduced bacteria, which could be effective in improving maize growth and yield as well as soil health.