Strategies for decolorization and detoxification of pulp and paper mill effluent

A comprehensive review on comparison among effluent treatment methods and modern methods of treatment of industrial wastewater effluent from different sources

In recent years, rapid development in the industrial sector has offered console to the people but at the same time, generates numerous amounts of effluent composed of toxic elements like nitrogen, phosphorus, hydrocarbons, and heavy metals that influences the environment and mankind hazardously. While the technological advancements are made in industrial effluent treatment, there arising stretch in the techniques directing on hybrid system that are effective in resource recovery from effluent in an economical, less time consuming and viable manner. The key objective of this article is to study, propose and deliberate the process and products obtained from different industries and the quantity of effluents produced, and the most advanced and ultra-modern theoretical and scientific improvements in treatment methods to remove those dissolved matter and toxic substances and also the challenges and perspectives in these developments. The findings of this review appraise new eco-friendly technologies, provide intuition into the efficiency in contaminants removal and aids in interpreting degradation mechanism of toxic elements by various treatment assemblages.

Spectral studies of Amaranthus tristis Linn. in Bioremediated Silk dyeing effluent with mixed biofertilizer inoculants

Microbial degradation as a treatment, with the combination of mixed inoculants of the Biofertilizer of Pseudomonas sp., Azospirillium sp. and Rhizobium sp., was employed for the remediation of Silk dyeing effluent. Remediating studies was undertaken to assess the feasibility of the mixed biofertilizer inoculant source for degradation of the Azodye effluent from the Silk dyeing Industry. The Green leafy vegetable (GLV), Amaranthus tristis Linn used as investigational prototypical plant species is selected for examining the phytochemicals, functional groups and its compounds grown in the effluent and biotreated environment and compared. The laboratory scale investigation showed that leaves, stem and root of the Amaranthus tristis Linn was qualitatively analysed for 20 phytochemicals which was grown in the different treatments of raw effluent and the biotreated effluent and the results showed the phytochemicals on the effluent’s influence reduced from strong positive to trace amounts while recovered on the biotreated environment. The FTIR analysis of the GLV grown in effluent and biotreated environments on comparison resulted in the functional group Alkene rescued in the biotreated effluent environment compared to the effluent contaminated area. The HPLC analysis of methanolic extracts of A. tristis grown in fresh water has 6 peaks of retention time of 2.6, 3, 3.9, 4, 4.2, and 4.6 RT whereas GLV effluent had only one peak of retention time of 4.1 RT. In the GLV from biotreated environment have 4 peaks were found with the maximum percentage area of 95.2% which proves that the compounds are rescued in the biotreated environment and few active compounds were confirmed in GCMS analysis. The Soil analysis results also indicate that the biotreatment of mixed inoculant of biofertilizers in the biotreated soil had influence resulting in improved levels of Ca, N, P and K with 114, 213, 10.5, 268 kg/ha respectively in the mixed inoculant biotreated soil. Similarly the micronutrients suchas Fe, Mn, Cu and Zn ranges to 4.1, 20.22, 2.13, 1.13 ppm respectively in the mixed inoculant biotreated soil within the optimal range. The study revealed that mixed biofertilizer inoculant has the recovery effect on the Silk dyeing (Azodyes) effluents effective reducing the pollutant capacity thereby meeting the discharged standards.

Insights into the resources generation from pulp and paper industry wastes: Challenges, perspectives and innovations

Pulp and paper industry is swiftly budding to fulfill industrial needs and with the growth of this industry, a large amount of waste has also generated which includes biological sludge generated from the wood digestion process, fly ash accumulation and lime mud produced in chemical reagent recovery circuit. There are many health hazards associated with generated wastes and this waste material can be utilized in sustainable ways to generate useful resources through technological innovations. This review highlights a few useful aspects of waste conversion to resources like the production of green energy, sorbent development, and clinker preparation. The generation of resources from such wastes is a revolutionary and innovative concept for sustainable development including valorization of the generated waste to integrate pulp and paper industry with biorefinery. This review paper focuses on the sustainable utilization of waste from such industry along with its efficiency and future challenges.

Fungal pretreatment of raw digested piggery wastewater enhancing the survival of algae as biofuel feedstock

BACKGROUND

Understanding about the impact of white rot fungi on indigenous bacterial communities, NH₄⁺ and turbidity in digested piggery wastewater, will allow the optimization of wastewater treatment methods and its use as a feasible medium for algal growth. Here, the white rot fungi were inoculated into undiluted and unsterilized digested piggery wastewater under different temperatures and pH regimes in order to lower the pretreatment cost. Diversity and abundance of the bacterial communities in the pretreated wastewater were assessed by PCR-denaturing gradient gel electrophoresis coupled with 16S rDNA sequencing.

RESULTS

The research showed a significant reduction on the microbial diversity with the presence of white rot fungi which occur at pH 6. The distribution and presence of bacteria taxa were strongly correlated with NH₄⁺ concentration, pH, and the presence of white rot fungi. Variance partition analysis also showed that the effect on the chlorophyll content of algae in fungi-filtered wastewater was as the following hierarchy: bacterial diversity > NH₄⁺ > turbidity. Therefore, the algae in treated wastewater with less abundance of bacteria proliferated more successfully, indicating that bacterial community not only played an important role in algal growth but also imposed a strong top-down control on the algal population. The algae grown in wastewater treated with fungi reached the highest specific growth rate (0.033 day^-1), whereas the controls displayed the negative specific growth rate. The fatty acid composition varied markedly in C16:0 and C18:0 between these treatments, with a higher content of C16:0.

CONCLUSIONS

This study firstly showed that Chlorella can grow as cost-effective biofuel feedstocks in undiluted and unsterilized digested wastewater with high ammonium concentration and dark brown color because the bacterial abundance of digested piggery wastewater could be reduced greatly by the white rot fungi.

Microbial dechlorination of chloroorganics and simultaneous decolorization of pulp-paper mill effluent by Pseudomonas putida MTCC 10510 augmentation

The physicochemical analyses of pulp-paper mill effluent revealed that it was dark brown with 1761 ± 2.3 color PtCo units having slightly alkaline pH, high biological oxygen demand and chemical oxygen demand values, and contained large quantities of organic and inorganic constituents, well above the prescribed standards. The bacterial growth, color reduction, and dechlorination were evident in all the four sets of experiments with different possible combinations of nutrient supplementation and Pseudomonas putida augmentation. A high degree of decolorization at 29.7% and 27.4% was observed by the effluent native microflora during 48 and 24 h, in unaugmented effluent supplemented with glucose + yeast extract and glucose + peptone, respectively. The extent of decolorization in glucose + yeast extract unaugmented effluent also corresponded with high degree of dechlorination (59.3%) during 60-h incubation (SET III). An appreciable level of growth, decolorization, and dechlorination was evident in nutrient unsupplemented P. putida augmented effluent as well as in the control natural effluent. However, a maximum level of growth response (OD 1.641-1.902) during 36-48 h, removal of color (39.72-48.2%) during 24-36 h, and chloride ions (80.1-83.5%) during 36 h was achieved in P. putida augmented effluent supplemented with glucose + yeast extract or peptone. Therefore, supplementation of effluent with glucose and yeast extract or peptone and concomitant augmentation with P. putida is required for efficient effluent decolorization and detoxification.