Value added product recovery from sludge generated during gum arabic refining process by vermicomposting.

Gum arabic is multifunctional and used in food products, pharmaceutical, confectionery, cosmetic, printing and textile industry. Gum arabic has an excellent market and its production is being increased to meet the market demand. In the process, huge quantity of solid waste is generated during its refining process. An attempt has been made to vermicompost this organic waste using Eudrilus eugeniae. This research work is first of its kind. Literature on this substrate has not been reported anywhere else for vermicomposting. Results were excellent with volatile solid reduction of 51.34 %; C/N ratio reduced to 16.31 % indicating efficient loss of carbon as carbon dioxide during vermicomposting period. Manurial value, i.e. nitrogen, phosphorus and potassium content in the range, required for the plants also increased. Porosity of 67.74 % and water holding capacity of 65.75 % were observed. The maturity of the vermicompost was evaluated through scanning electron microscopy wherein the complete conversion of large raw material particles into finer particles forming a uniform matrix with more surface area was observed indicating its efficient conversion. Microbial quality of vermicompost was also studied. The final vermicompost is free of fungal cells and pathogenic bacteria.

Comparative study on toxicity evaluation of anaerobically treated parboiled rice manufacturing wastewater through fish bioassay.

Short term aquatic bioassay has been developed into a useful tool in water quality management. These tests give information on comparative toxicity of several compounds. The objective of this study was to evaluate the acute toxicity of raw and anaerobically treated effluents of the parboiled rice manufacturing industry. The acute toxicity test was carried out by using the fish Lebistes reticulatus under laboratory conditions. LC50 values for 24, 48, 72 and 96 hours ranged between 4.6 and 7.0% for the raw parboiled rice manufacturing wastewater. Two anaerobic fixed film fixed bed reactors and two different media matrices, i.e. UV stabilized Biopac media and Fugino spirals, were used for the treatment of parboiled rice mill wastewater. Effluents from these two reactors depicted LC50 values in the range of 68-88% and 62-78% for Biopac and Fugino spiral packed reactors, respectively. From the results, it is evident that anaerobically treated effluents from Biopac packed reactor is marginally better than Fugino spiral packed reactor. Results subjected to statistical evaluation depicted regression coefficient of more than 0.9 indicating good correlation between the mortality and effluent concentration.

Kinetic analysis of an anaerobic fixed-film fixed bed-reactor treating wastewater arising from production of a chemically synthesized pharmaceutical.

The kinetics of the treatment of a pharmaceutical wastewater (PW), pretreated in a first stage by electrocaogulation (EC), using an anaerobic fixed-film fixed-bed reactor was investigated. The experimental results for the substrate removal kinetics were found to be in good agreement with those of the Monod model and the modified Stover-Kincannon model, with a high regression value (R2 > 0.9). For the modified Stover-Kincannon model, the constants U(max), and K(B) were found to be 13.1 and 13.87 kg COD/(m3 x d) respectively. With reference to the biomass kinetics, the increase in organic loading rate (OLR) is attributed to the increased biomass growth rate (micro) and decrease in the biological constant K(micro). The corresponding constants for the modified Monod's model, i.e. 'micro(max) and decay constant K(d), were found to be 0.159 and 0.0113 d(-)1 respectively. Finally, the gas production kinetics was interpreted in relation to the Kincannon-Stover model.

Effect of selected heavy metals on the histopathology of different tissues of earthworm Eudrillus eugeniae.

Laboratory-scale experiments were conducted to determine the effect of heavy metals viz. copper (Cu), cadmium (Cd), chromium (Cr), lead (Pb), and zinc (Zn) on the different vital tissues of earthworm Eudrillus eugeniae such as head, gizzard, clitellum, and intestine after the worms were placed in municipal solid waste (MSW) substrate spiked with heavy metals in the concentration range of 0.05 g/kg to 1.0 g/kg of the waste for Cu, Cr, PB, and Zn and 0.05 g/kg for Cd. The experiments were conducted for 100 days with periodic observations and sample collection for investigation after every 10th day. Copper and lead metals were found to cause more deleterious effect in head, gizzard, and intestine. Chromium metal caused cellular damage to the intestinal region. In comparison, cadmium metal severity was more than copper, lead, and chromium metal. Zinc metal did not show deleterious effect on tissues. In general, earthworms can be used as biomarkers in toxicity studies related to heavy metals at cellular levels.

Vermifilters: a tool for aerobic biological treatment of herbal pharmaceutical wastewater.

Herbal pharmaceutical wastewater possesses high chemical oxygen demand (COD) (21,960-26,000 mg/l) and biochemical oxygen demand (BOD) (11,200-15,660 mg/l) and suspended solids (SS) (5,460-7,370 mg/l). It cannot be directly discharged into surface water bodies, due to its highly biodegradable nature. Herbal pharmaceutical wastewater has been treated by using vermifilter, which is an ecosystem consisting of biosoil with bacteria and earthworms producing vermicastings. In the present studies a cost-effective, eco-friendly and sustainable method has been applied for the treatment of herbal pharmaceutical wastewater using earthworms. Studies were carried out at different organic loadings, ranging between 0.8 and 3.2 kg COD/m(3)day at three different hydraulic loadings of 1, 2 and 4 days. Vermifilters packed with 1:1:1 ratio of soil, sand and vermicast as media matrix along with the twenty adult earthworms in each reactor was used for the experiments. Treated effluent was colour and odour free. Efficient COD/BOD removals in the range of 85.44%-94.48% and 89.77%-96.26% were obtained respectively at 2 days hydraulic retention time (HRT). Heavy metal removals were also observed and no sludge production problem was encountered, only nutrient rich vermicast from the filters were removed and analysed after the experiments. It showed higher manurial value than control in terms of available nitrogen, phosphorus and potassium (NPK) and were in the range of 178.75-278.75 Kg/hectare available nitrogen, 16.128-50.4 kg/hectare of available phosphorus and 19.3-28.6 kg/hectare of available potassium at maximum HRT and at different organic loadings. This paper discusses in detail the feasibility of vermifilters in herbal pharmaceutical wastewater treatment at different organic and hydraulic loadings.

Toxicity of herbal pharmaceutical wastewater to a freshwater crustacean Ceriodaphnia dubia.

The main objective of this study was to evaluate the acute toxicity of raw, neutralized and physico-chemically treated and biologically treated effluent of herbal pharmaceutical industry. The acute toxicity test was determined using freshwater crustacean Ceriodaphnia dubia under laboratory conditions. LC(50) values for raw, neutralized and physico-chemically treated effluent for 12, 24, 36 and 48 h ranged between 3.0-4.5%, 3.9-10.8% and 22-28% respectively. It is evident from the results that physicochemical treatment reduced the toxicity by around 25% while biological treatment reduced the toxicity completely. Results subjected to statistical evaluation depicted regression coefficient of more than 0.9 indicating good correlation between the mortality rate and effluent concentrations.

Influence of anode material on electrochemical oxidation for the treatment of tannery wastewater.

The treatment of tannery wastewater by electrochemical oxidation, mediated by an electro-generated species was carried out under galvanostatic conditions in an electrochemical reactor equipped with anodes based on noble metals and metal oxides (Ti/Pt-Ir, Ti/PbO2, Ti/PdO-Co3O4 and Ti/RhO(x)-TiO2). The decrease in time of chemical oxygen demand, nitrogen (TKN and ammonia), Cr and sulphides was monitored. The study showed that the rate of pollutant removal was significantly influenced by the type of anode material and electrochemical parameters. Different mechanisms contributed to the removal of pollutants when the reactor operated under conditions close to the limiting current for chlorine evolution and under much higher current density, with the reactor performing better at a high current/voltage. The kinetic pseudo-first order model applied for the interpretation of the results showed that the Ti/Pt-Ir and Ti/PdO-Co3O4 anodes performed better than the other two electrodes under the majority of tested conditions, with the highest rate of removal obtained for ammonia (kinetic rate constant k=0.75 min(-1)). Electrochemical oxidation can be applied as a post-treatment after the conventional biological process in order to remove the residual ammonia with low energy consumption (0.4 kWh m(-3)).

Bioaccumulation studies of organochlorinated pesticides in tissues of Cyprinus carpio.

Freshwater fish Cyprinus carpio was selected for the study of bioaccumulation of organochlorinated pesticides in tissues like gills, muscle, intestine, kidney, and liver in a continuous fed system. The pesticides used were Aldrin, Dieldrin, BHC, and DDT. The bioaccumulation of Dieldrin was maximum of 85.0 microg g(-1) wet weight in liver tissue while minimum of 7.30 microg g(-1) wet weight for DDT at 30 days exposure time. Bioconcentration factor (BCF) has followed the same trend in liver tissue for Dieldrin and DDT. The rate of bioaccumulation was found to be maximum of 4.3879 microg g(-1) wet weight in liver tissue and minimum of 0.0021 microg g(-1) wet weight in gill tissue for 30 days exposure. As evidenced by the increasing values of BCF, pesticide uptake also showed increased trend with the increase in exposure time. A high correlation coefficient ranging between 0.7247 and 0.9616 between the pesticide concentration and exposure time was observed. Based on actual BCF values, log Kow were calculated and the values are well within the reported values of 6.5 indicating efficient relationship between BCF and log Kow because beyond the 6.5 the bioconcentration levels off.

Impact of some chlorinated pesticides on the haematology of the fish Cyprinus carpio and Puntius ticto.

The effects of pesticides on blood characteristics and histological changes in erythrocytes of the fish species Cyprinus carpio and Puntius ticto were studied. The fishes were exposed to sub lethal concentrations of different chlorinated pesticides namely aldrin, dieldrin, DDT, BHC and chlordane for 10, 20 and 30 d in continuous flow-through test. The LC50 values were calculated based on acute toxicity tests and the sublethal doses were arrived at for chronic bioassay studies. Results showed an increase in haemoglobin content of both Cyprinus carpio and Puntius ticto in case of aldrin and dieldrin. Haemoglobin content reduced from an initial 13 g/100 ml to 8.07 and 10.15 g/100 ml in case of Cyprinus at the end of ten days exposure to aldrin and dieldrin respectively, and gradually increased to 8.7 g/100 ml and 10.15 g/100 ml after 20 d of exposure. The haemoglobin content after 30 d exposure to aldrin and dieldrin was 10.15 g/100 ml and 11.6 g/100 ml respectively. In case of Puntius ticto, the haemoglobin content in control fishes recorded was 12.8 g/100 ml while in case of fish exposed to aldrin, the haemoglobin content reduced initially on ten days exposure to 10.15 g/100 ml and increased to 11.6 g/100 ml and 13.0 g/100 ml during twenty days and thirty days exposure respectively. This trend was also observed with dieldrin in both the fishes studied. Red blood cells were also counted in case of all the pesticides and exposure periods with respect to Cyprinus carpio and Puntius ticto. Irrespective of the species and pesticide, the RBC counts uniformly showed decreasing trend with the increase in exposure period, while packed cell volume, PCV(%) showed increasing trend with respect to increase in exposure period in case of aldrin and dieldrin in both the fishes. But DDT, BHC and chlordane showed decreasing trend in PCV(%) values with increasing periods of exposure.

Bioaccumulation kinetics and bioconcentration factor of chlorinated pesticides in tissues of Puntius ticto (Ham.).

Bioaccumulation kinetics and bioconcentration factor (BCF) of chlorinated pesticides like Aldrin, Dieldrin, Benzene hexachloride (BHC), and Dichlorodiphenyl-dichloro-ethane (DDT) in fish tissues of Puntius ticto was studied in detail in a continuous fed system. The bioconcentration process is summarized by using a first order uptake model and the steady-state BCF is calculated based on the 30 days exposure. Rate of bioaccumulation of DDT was maximum of 4.6432 microg g(-1) wet weight per day in liver tissue whereas it was minimum of 0.0002 microg g(-1) wet weight per day in case of Dieldrin in the muscle tissue among the pesticides. It was observed that DDT showed maximum BCF of 89.010 in case of liver tissue of the fish exposed to 30 days. The regression coefficient (r2) between pesticide concentration and exposure time varied between 0.6212 and 0.9817 indicating high correlation. Based on actual calculated BCF values, the octanol water partition coefficient (Kow) values were predicted. In order to prove the hydrophobic property of chlorinated compounds and its affinity towards lipid, the Kow is predicted. Results showed that pesticide burden differ from tissue to tissue and can be correlated to the lipid content, size, exposure time, and species.

Organic removals from highly proteinous wastewater from soya milk and tofu manufacturing plant.

Combined wastewater from soya milk and tofu manufacturing industry was treated by physico-chemical method using conventional coagulants such as lime, alum. ferric chloride, and ferrous sulphate in combination with synthetic cationic polyelectrolyte. The wastewater samples were analyzed as per the Standard Methods and the experiments were carried out using Jar test apparatus (Phipps & Birds). The ferric chloride in combination with synthetic cationic polymer (Oxyfloc-FL-11) in the ratio of 250:20 mg L(-1) resulted in very good removals of COD, BOD, and SS of 75.4, 79.8, and 96.0% respectively with complete removal of odor, color and turbidity.

Toxicity of herbal pharmaceutical wastewater on fish--Lebistes reticulatus (Peter).

Toxic effects of herbal pharmaceutical wastewater on common fish (Lebistes reticulatus) under laboratory conditions were studied. LC50 values for raw, neutralized, and physico-chemically treated effluent for 24, 48, 72, and 96 h ranged between 3.0-9.5%, 5.0-10.5%, and 35-41%, respectively. It was evident from the studies that physico-chemical treatment reduces the toxicity by more than 30%. This article discusses in detail the bioassay evaluation of raw, neutralized, and primary treated effluent. Physico-chemically treated effluent was further subjected to biological treatment by activated sludge system. Effluent from biological treatment revealed no toxic effect even after one month of exposure.

Treatment of spent broth from an antibiotic manufacturing unit using anaerobic fixed film fixed bed reactor.

Studies on bench scale reactor were undertaken to determine its performance at various organic loading rate (OLR) and hydraulic retention time (HRT). The results indicated BOD and COD removals in the range of 67.2-77.4% and 57.8-69.1% respectively at the OLRs between 0.84 and 2.5 kgCOD/m3 d and HRT of 10 days. Daily gas production was measured by gas flow meter. Daily gas production varied between 0.268 and 0.326 m3/kgCOD added at the different OLRs. Studies were also carried out at lower HRT of 5 days. But BOD/COD removals reduced and correspondingly gas production also reduced. Gas composition remained constant at both the HRT and the Methane content was around 65-68% while the CO2 was around 32-35%. This paper discusses in detail the feasibility of upflow anaerobic fixed film fixed bed (UAFFFB) reactor system in treating the strong spent broth from the antibiotic industry.

Kinetics of an anaerobic moving bed reactor system treating synthetic milk wastewater.

In the present study, anaerobic moving bed reactor called anaerobic rotating biological contactor treating synthetic milk wastewater operated at different organic loading rates and different hydraulic retention times, were evaluated to determine kinetic parameters for the substrate, biomass and biogas based on various models. The maximum substrate loading rate and half velocity constant were evaluated as 5.71 kgCOD/m3 x d and 1178 mg/L respectively by using Lineweaver-Burke plot. Maximum substrate removal efficiency and critical hydraulic retention time were compared with modified Young and McCarty model and the model is best fitted for the study. The complete removal of substrate cannot be expected due to presence of metabolic refractory material produced within the reactor system from influent system. Kinetic constants for maximum specific growth rate and decay coefficient were compared with the modified Monod model. Kornegay and Andrews model were used to evaluate the area capacity constant and half velocity constant. Kinetic constants for maximum specific gas production rate and proportionality constant were evaluated using Stover model. The gas production and quality are dependent on the substrate removal and substrate loading rate. The kinetic relationships derived from lab-scale experiment provided good estimates of the performance of pilot- and full-scale anaerobic rotating biological contactor packed with fibrous nylon pads and treating synthetic milk wastewater in terms of the effluent chemical oxygen demand concentrations and specific biogas production rates.