Challenges in developing strategies for the valorization of lignin-a major pollutant of the paper mill industry.

Apart from protecting the environment from undesired waste impacts, wastewater treatment is a crucial platform for recovery. The exploitation of suitable technology to transform the wastes from pulp and paper industries (PPI) to value-added products is vital from an environmental and socio-economic point of view that will impact everyday life. As the volume and complexity of wastewater increase in a rapidly urbanizing world, the challenge of maintaining efficient wastewater treatment in a cost-effective and environmentally friendly manner must be met. In addition to producing treated water, the wastewater treatment plant (WWTP) has a large amount of paper mill sludge (PMS) daily. Sludge management and disposal are significant problems associated with wastewater treatment plants. Applying the biorefinery concept is necessary for PPI from an environmental point of view and because of the piles of valuables contained therein in the form of waste. This will provide a renewable source for producing valuables and bio-energy and aid in making the overall process more economical and environmentally sustainable. Therefore, it is compulsory to continue inquiry on different applications of wastes, with proper justification of the environmental and economic factors. This review discusses current trends and challenges in wastewater management and the bio-valorization of paper mills. Lignin has been highlighted as a critical component for generating valuables, and its recovery prospects from solid and liquid PPI waste have been suggested.

Bio-organic fertilizer production from industrial waste and insightful analysis on release kinetics.

The present study has been designed to utilize industrial and agricultural solid waste for NPK (Nitrogen-Phosphorus-Potassium) bio-organic fertilizer production and its optimized use. The collagenic material of wet blue leather (WBL) from leather industry was used as nitrogen source, after H3PO4 acid-mediated chromium removal. Chicken meat-bone meal (CMBM) and rice husk ash (RHA) are abundantly available locally, had used as P, K, and Ca sources. The presence of N, P, K, Ca in the produced bio-organic NPK fertilizer were 10.76, 11.03, 3.41, 13.64, respectively as per mixing ratio of ingredients. In this study it was effect on the chili plant (Capsicum annuum L.) growth and revealed 1.15 and 1.03 fold higher plant growth, 1.40 and 1.18 fold higher total chlorophyll content than untreated soil (control), and chemical fertilizer. The liberation of fertilizers components from their source, transport of fertilizer components in the soil, and absorption in plant roots have been studied using mathematical models indicating the optimum fertilizer use for better productivity and to reduce loss of extra fertilizer and eutrophication. The formulation showed excellent water retention capability (3.2 L/kg), which might increase soil water availability to the plants and eventually reduce water demand and labour cost. DNA intercalation study proved there is no harm to use this fertilizer.

Chitosan based micro and nano-particulate delivery systems for bacterial prodigiosin: Optimization and toxicity in animal model system.

Prodigiosin, a red bacterial pigment is a compound with promising therapeutic properties. Major hindrance in applying prodigiosin in pharmaceutics is the insolubility in water and lack of bioavailability. This study aims to optimize two different types of chitosan based delivery systems, microspheres and nanoparticles for prodigiosin derived from Serratia marcescens NITDPER1 through Taguchi method and determine toxicity perspectives. The results revealed 0.5 % chitosan, 1 % sodium-alginate and 5 % CaCl2 optimum for microsphere and 0.1 % chitosan, 1.5 % TPP and 1.5 % acetic acid for nanoparticle with the entrapment efficiency and maximum release of 89.27 ± 1.2 % and 87.42 ± 1.9 % for microspheres and 96.36 ± 1.7 % and 91.58 ± 2.1 % for nanoparticles. Particle size was 93.03 ± 0.3 µm and 75.1 ± 1.4 nm for micro and nanoformulations. Kinetic parameters of release fitted best with Korsmeyer-Peppas model. Swelling index of microsphere and nanoparticles in pH 6.8 was 799 ± 7.1 % and 35.3 ± 2.1 % respectively. FESEM, FT-IR and XRD revealed spherical morphology, preservation of prodigiosin functional groups and amorphous nature of the formulations. Anticancer IC50 values were (µg mL-1) 11.7 ± 1.2, 10.8 ± 1.4 and 9.4 ± 0.8 for free prodigiosin, microsphere and nanoparticles respectively. Toxicity studies on HEK-293 cell line, Daphnia magna and zebrafish model determined non-toxic nature of the bacterial prodigiosin and its formulations revealing suitability of animal system application.

Ecotoxicological risk assessment of pentachlorophenol, an emerging DBP to plants: evaluation of oxidative stress and antioxidant responses.

Chlorophenols are not only noticed in an effluvium of industries but also can emerge from the water treatment plants for domestic supply which poses a high threat for crop production and human health. Therefore, research on their risks to ecosystem and human health via ecotoxicological tests to derivate permissible environmental contaminant concentrations is necessary. The chlorophenols produced in the course of chlorination of potable water is an outcome of natural carboxylic acids/organic material and those chlorophenols occurred as emerging disinfection byproducts (EDBPs). Among chlorophenols, pentachlorophenol (PCP) has been recently identified as one of the important EDBPs. The main objective was to evaluate the PCP-induced genotoxicity and the oxidative damage in two plant species, i.e., Allium cepa and Vigna radiata. Genotoxicity of PCP was examined at three selected concentrations based on EC50 (half-maximal effective concentrations) values in both the plants along with the defense mechanism. EC50 value for A. cepa and V. radiata was 0.7 mg/L and 35 mg/L. Root length inhibition, DNA laddering, lipid peroxidation, H2O2 content, and antioxidant enzymatic assays evaluated revealed a dose-dependent response. PCP influenced defense enzyme glutathione peroxidase (GPX) and ascorbate peroxidase (APX) action in both plants and showed deprivement of catalase (CAT) with the increase of PCP concentrations. PCP-invaded toxicity management by these plants implied that A. cepa is more sensitive than V. radiata regarding PCP-induced toxicity.

Transforming wet blue leather and potato peel into an eco-friendly bio-organic NPK fertilizer for intensifying crop productivity and retrieving value-added recyclable chromium salts.

An attempt has been made to address two important issues, the solid waste management of leather industry and soil fertility. The SEM images revealed altered surface-morphology.The EDS elemental analysis exhibited presence of about 13.2% nitrogen (N), 50.56% carbon (C), 2.69% phosphorus (P) in the collagenous material of wet blue leather (WBL) after chromium removal. In potato peel biochar (PPB) prepared the EDS analysis corroborated the presence of N P K in 5%, 1.4% and 21.64% respectively. In the formulated bio-organic NPK fertilizer, using chromium free WBL and PPB, the percentage of N, P, K, was in 13.10, 2.41, 20.20% respectively which was authenticated by EDS. Its effect on okra (Abelmoschus esculentus) plant showed higher growth (1.11 fold fruit size) and total chlorophyll content (1.61 fold) than in untreated soil (control) but displayed similar result as in presence of chemical fertilizer. The released free ammonia in soil with bio-organic NPK was more (37.02%) than with chemical fertilizer (6.10%). DNA intercalation study showed the non-hazardous impact on soil. The FTIR, XRD, SEM-EDS, AAS further specified the conversion of the WBL extracted acidic chromium-rich solution by MgO into crystalline chromium for commercial use.

Mechanistic insight for DBP induced growth inhibition in Vigna radiata via oxidative stress and DNA damage.

Chlorination is important to the safeness of recouped water; though it shows concern about disinfection by-products (DBPs) formation and its toxic effects. DBPs generation mostly specified by category of disinfectant utilized and naturally occurring organic matter present in the water pre and post disinfection. Plants are exposed to diverse stresses of environment across their lifespan. Reactive oxygen species (ROS) perform significant roles in preserving ordinary plant growth and enhancing their tolerance towards stress. This study is focused on the generation and elimination of ROS in apical meristematic growth and responses in Vigna radiata towards DBPs exposure. Phytotoxic and genotoxic effect of selected DBPs, TCAA (trichloroacetic acid), TCM (trichloromethane), TBM (tribromomethane) revealed concentration-dependent root length inhibition, germination index, vigour index, tolerance index, root/shoot ratio with higher EC50 value for TCM (6000 mg/L, 50.26 mM) over TCAA and TBM (1850 mg/L, 11.32 mM; 4000 mg/L, 15.83 mM). DNA laddering assay demonstrated DBP induced DNA damage to be concentration-dependent too. The concentration-dependent increase in the lipid peroxidation, H2O2 generation for each DBPs examined with highest oxidative stress for TCAA over TBM and TCM at fixed concentration illustrates that possible mechanism behind observed toxicity may be via ROS. Its regulation by antioxidative defense enzymes activities can be attributed to observed decline in these enzymes (catalase, ascorbate peroxidase, guaiacol peroxidase) activities with increasing concentration again where TCAA found more significantly affected than TBM and TCM over control. Results thus provide a useful understanding of the mechanism of DBP induced phytotoxicity and genotoxicity in V.radiata.

Environmental risk appraisement of disinfection by-products (DBPs) in plant model system: Allium cepa.

The organic toxicants formed in chlorinated water cause potential harm to human beings, and it is extensively concentrated all over the world. Various disinfection by-products (DBPs) occur in chlorinated water are genotoxic and carcinogenic. The toxicity is major concern for chlorinated DBPs which has been present more in potable water. The purpose of the work was to evaluate genotoxic properties of DBPs in Allium cepa as a plant model system. The chromosomal aberration and DNA laddering assays were performed to examine the genotoxic effect of trichloroacetic acid (TCAA), trichloromethane (TCM), and tribromomethane (TBM) in a plant system with distinct concentrations, using ethyl methanesulfonate (EMS) as positive control and tap water as negative control. In Allium cepa root growth inhibition test, the inhibition was concentration dependent, and EC50 values for trichloroacetic acid (TCAA), trichloromethane (TCM), and tribromomethane (TBM) were 100 mg/L, 160 mg/L, and 120 mg/L respectively. In the chromosome aberration assay, root tip cells were investigated after 120 h exposure. The bridge formation, sticky chromosomes, vagrant chromosomes, fragmented chromosome, c-anaphase, and multipolarity chromosomal aberrations were seen in anaphase-telophase cells. It was noticed that with enhanced concentrations of DBPs, the total chromosomal aberrations were more frequent. The DNA damage was analyzed in roots of Allium cepa exposed with DBPs (TCAA, TCM, TBM) by DNA laddering. The biochemical assays such as lipid peroxidation, H2O2 content, ascorbate peroxidase, guaiacol peroxidase, and catalase were concentration dependent. The DNA interaction studies were performed to examine binding mode of TCAA, TCM, and TBM with DNAs. The DNA interaction was evaluated by spectrophotometric and spectrofluorometric studies which revealed that TCAA, TCM, and TBM might interact with Calf thymus DNA (CT- DNA) by non-traditional intercalation manner.