Search

Present study focused on the effective utilization of red algae (Rhodophytasp.) towards removal of fluoride from contaminated medium by varying the operating variables (pH, adsorbent dose, initial concentration, contact time and temperature) and screen out the best condition for removal of fluoride through response surface optimization technique. The algal biomass was characterized by various analytical instruments, such as scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectrometry and point of zero charge (pHZPC). Results revealed that the equilibrium data nicely fitted with Langmuir model with biosorption capacity 5.484 mg g−1. The optimized values was screed from response surface methodology as initial concentration, temperature, dose and contact time are 9.77 mg L−1, 302.63 K, 10.8 g L−1, and 23.17 min, respectively. Finally, optimized condition was applied for removal of fluoride from fluoride contaminated villages of Birbhum district and average 80% fluoride was removed. The exhausted adsorbent was regenerated (95%) using 0.1 N NaOH solution. Therefore, present finding suggest that the red algae (Rhodophytasp.) could be an excellent biosource for decontamination of fluoride from underground water.

•Investigated methylene blue (MB) dye adsorption-degradation by laboratory fabricated Ag doped TiO2nanoclusters.•The Ag@TiO2exhibited the MB removal of 96.67% of 0.02% (W/V: g/mL) catalysis doses.•Scavenger effect revealed the oxidative damage on MB using Ag@TiO2.•Recycle study exhibited the loss of efficacy according to TiO2(6.35%) > Ag@TiO2(4.33%) > AgNPs (2.38%).•Fukui faction was exhibited maximum cleavage with nucleophilic and electrophilic for N−N, C−N or C−C bonds.

Heavy metal contamination in agricultural soil is a prime concern for food security and human health. A short-term phytotoxicity experiment was conducted on four varieties of rice (Oryza sativaL.) under the influence of arsenic (III)-arsenite and arsenic (V)-arsenate to evaluate the impact on root and coleoptile growth. Four varieties (GB-1, IET-4786, IET-4094, and MTU-1010) of rice were tested with different concentrations (0, 5, 10, 25 and 50 mg/L) of arsenic (As(III) and As(V)). Germination along with mean daily germination (MDG), length of root and length of coleoptiles, water holding capacity of both root and coleoptiles, fresh and dry weight, arsenic accumulation, malondialdehyde (MDA) and root ion leakage were evaluated. Results highlighted that the percent germination of IET-4094 and MTU-1010 varieties of rice seed compared to control decreased significantly (p< 0.05) with increasing concentration of both arsenite and arsenate. Similarly, biomass of shoot was less affected than root under different concentration of arsenite and arsenate. The variety IET-4786 and MTU-1010 accumulated lower level of arsenic and the variety GB-1 accumulated higher level of MDA in roots under both arsenite and arsenate treatments. Therefore, it can be concluded that the varieties IET-4786 and MTU-1010 are more suitable varieties towards tolerance under both arsenite and arsenate. Farmers of arsenic contaminated areas are suggested to cultivate IET-4786 and MTU-1010 varieties.