Phenol biodegradation using bio-filter tower packed column with immobilized bacterial consortium: a batch test study.

The effluents from pulp and paper manufacturing industries contain high concentrations of phenol, which when discharged directly into surface water streams, increases the biological oxygen demand (BOD) and chemical oxygen demand (COD). In this study, two dominant bacteria SP-4 and SP-8 were isolated from the effluent emanating with a pulp and paper industry. The selected phenol-degrading isolates were identified as Staphylococcus sp. and Staphylococcus sciuri respectively by using nucleotide sequence alignment and phylogenetic analysis of 16 S rRNA regions of the genome. The two isolates used for the biodegradation process effectively degraded phenol concentration of pulp and paper industry effluent upto 1600 and 1800 mg/L resepctively. The individual isolates and consortium were immobilized using activated carbon, wood dust, and coal ash. Additionally, the effluent was treated using a bio-filter tower packed column immobilized with bacterial cells at a constant flow rate of 5 mL/min. The present study showed that the developed immobilized microbial consortium can effectively degrade 99% of the phenol present in pulp and paper industry effluents, resulting in a significant reduction in BOD and COD of the system. This study can be well implemented on real-scale systems as the bio-filter towers packed with immobilized bacterial consortium can effectively treat phenol concentrations up to 1800 mg/L. The study can be implemented for bioremediation processes in phenolic wastewater-contaminated sites.

Morphological response of Cicer arietinum exposed to paper mill effluent.

The present study was conducted to assess the effect of different concentrations (control, 25, 50, 75 and 100%) of paper mill effluent on some morphological characters of Cicer arietinum. Result showed maximum growth promotion i.e., root length (3.8 cm), shoot length (10.0 cm) and increase in chlorophyll content (1.004 mg gm(-1)) at 50% effluent concentration after 21 days. However, at higher effluent concentration growth parameters started decreasing. The study suggests that the effluent can be used safely for Cicer arietinum cultivation only after proper dilution up to a certain extent.

Evaluation of corrosion and scaling tendency of polyester textile dyeing effluent, Haridwar, Uttarakhand, India.

Textile dyeing industries are regarded as one of the most polluting by virtue of the chemicals used and wastewater released. A great deal of chemicals, fasteners, dispersing agents is employed in the stages of dyeing and finishing. The aim of the study was to evaluate scaling and corrosion tendency of polyester textile dyeing effluent using Langelier saturation index (LSI), Ryznar stability index (RSI), and aggressiveness index (AI). The estimation of water stability indices helps in assessing the scaling and corrosive nature of wastewater which in turn facilitates evaluating the condition of the pipelines and valves. Wastewater released from textile dyeing units contains high levels of color (892 ± 20Pt-Co), chemical oxygen demand (2461 ± 48.45 mg/L), electrical conductivity (2906 ± 5.77 µS/cm), and sulfate (6620 ± 7.22 mg/L). The LSI ranged from 2.12 to 3.45, RSI varied from 2.84 to 5.62, and AI varied from 13.67 to 14.99. It was found from the results that the polyester textile dyeing effluent was scaling and non-aggressive. Also, the pipes containing this effluent have to undergo regular maintenance so that they are not blocked by scales which can render financial losses to the industry.

Kinetic Study for Startup of Aerobic Moving Bed Biofilm Reactor in Treatment of Textile Dye Wastewater.

Due to high augmentation in population and low availability of land, the quantum of wastewater production has surged resulting in advancements in wastewater treatment systems. To cope under such stressful circumstances, moving bed biofilm reactor (MBBR) proves to be an upgraded treatment technology for industrial and municipal wastewater treatment. The present startup study has been carried out using a laboratory-scale aerobic MBBR with working volume of 25L for textile dye wastewater treatment having AnoxKaldnes K3 media at filling percentage of 50%. In order to acclimatize the microorganisms on textile dye wastewater, the startup of the reactor was carried out using lactose as readily degradable co-substrate with textile dye wastewater in different ratios at hydraulic retention time (HRT) of 24 h. The biofilm on the media was developed in 63 days duration and the reactor attained pseudo-steady state (PSS) in 185 days period. During PSS condition of the MBBR, the maximum chemical oxygen demand (COD) removal efficiency of 92% with mixed liquor suspended solids (MLSS) concentration of 4224 ± 22 mg/L has been achieved. The kinetic study for biodegradation of textile dye wastewater has also been carried out using the Monod growth kinetics. The values of bio-kinetic coefficients of yield of heterotrophic biomass (Y) and endogenous decay coefficient for heterotrophic biomass (Kd) recorded are 0.394 mgVSS/mgCOD.d and 0.087 day-1, respectively. The values of specific substrate removal rate (k), Monod half saturation constant (Ks), and maximum specific growth rate for heterotrophic biomass (µmax) are 0.024 mgCOD/mgVSS.d, 53.203 mg/L, and 0.0095 day-1, respectively, demonstrating the suitability and healthy performance of MBBR for textile dye wastewater treatment.

A comparative study on compost preparation using lab prepared eco-enzyme and its effect on growth of plant species Phaseolus vulgaris.

The augmented rise in population in the last few decades has resulted in gigantic increase in the solid waste production in India and around the globe. The conventional composting methods are slow and sluggish process that has resulted in the advancement techniques for the emergence in new rapid composting processes. Use of eco-enzyme is such a rapid technique that helps to degrade the solid waste in a very accelerative manner. The present study has been carried out by preparing eco-enzyme using the kitchen waste and with the objective to utilize it for degradation of agricultural wastes and preparing compost for its utilization for different plant species as soil conditioner and fertilizer. The prepared eco-enzyme was added during the composting process in each batch with concentration variations of 10%, 15%, and 20% (V/V) once every week. The pH value of the final prepared compost was found to be within the neutral range of 6.51 ± 0.03-7.88 ± 0.50 in all the samples. Overall compost prepared using 10% eco-enzyme has the highest growth promoting effects for Phaseolus vulgaris. The present study will be having twofold advantage as the environment will get rid of such wastes as the same can be utilized as resource and it will also be helpful for the farmers from economical point of view.

Microbial diversity during Rotary Drum and Windrow Pile composting.

This study investigates the prevailing microbial communities during the composting of vegetable waste, cattle manure and saw dust, in a household (250 l) batch scale Rotary Drum composter and Windrow Pile. Physico-chemical parameters were analyzed to study the organic matter transformations. Total organic matter reduced from 63.8% to 36.2% in rotary drum and 39.6% in windrow pile composting. The C/N ratio decreased from 26.52 to 8.89 and 14.33 in rotary drum and windrow pile composting. The indigenous population of total heterotrophic bacteria decreased in rotary drum and windrow pile composting after 20 days. However, total fungal load initially increased within initial 4 days, then subsequently reduced in final composts. The average number of fecal coliforms and fecal Streptococci showed decrement with time, in both composting systems. Escherichia coli and Salmonella species number deduced during the study. Composting cycle started with Gram positive rods but ended up with the dominance of Gram negative bacilli shaped bacteria. Transformation of organic compounds during the biodegradation of organic waste, difference in the utilization of nutrients (organic matter) by the different group of microbes and high temperature could be cited as a possible reason of the above changes. Scanning electron microscopy has been used to obtain the surface structures of the cultured mycoflora. Results of the study revealed that higher diversity of microbes prevailed in rotary drum as compared to windrow pile, yielding more stable and pathogenic free compost in lesser period of composting.

Diversity of bacterial isolates during full scale rotary drum composting.

Bacterial diversity of full scale rotary drum composter from biodegradable organic waste samples were analyzed through two different approaches, i.e., Culture dependent and independent techniques. Culture-dependent enumerations for indigenous population of bacterial isolates mainly total heterotrophic bacteria (Bacillus species, Pseudomonas species and Enterobacter species), Fecal Coliforms, Fecal Streptococci, Escherichia coli, Salmonella species and Shigella species showed reduction during the composting period. On the other hand, Culture-independent method using PCR amplification of specific 16S rRNA sequences identified the presence of Acinetobacter species, Actinobacteria species, Bacillus species, Clostridium species, Hydrogenophaga species, Butyrivibrio species, Pedobacter species, Empedobactor species and Flavobacterium species by sequences clustering in the phylogenetic tree. Furthermore, correlating physico-chemical analysis of samples with bacterial diversity revealed the bacterial communities have undergone changes, possibly linked to the variations in temperature and availability of new metabolic substrates while decomposing organics at different stages of composting.