Coffee processing industrial wastewater treatment using batch electrochemical coagulation with stainless steel and Fe electrodes and their combinations, and recovery and reuse of sludge.

The efficiency of chemical oxygen demand (COD) and color removal from raw coffee processing wastewater (CPWW) using batch electrochemical coagulation (BECC) treatment process using stainless steel (SS) and iron (Fe) electrode combinations are investigated. Of the combinations: four SS, four Fe, Fe-Fe-SS-SS, Fe-SS-Fe-SS, SS-SS-Fe-Fe, and SS-Fe-SS-Fe; four SS electrodes operated at 23 V having 120 A/m2 current density was found as a good operating condition to achieve ∼87% COD removal from its initial COD of 1,984 mg/L and corresponding color removal of 97.1% (initial color 7,000 PCU). The second best electrode combination, SS-SS-Fe-Fe, had COD and color removals of 75% and 91%. When using polyaluminum chloride (PAC) as aid with different dosages of 20-100 mg/L, 50 mg/L PAC showed maximum COD and color removals of 80% and 92%. Comparison of proximate and ultimate analyses of various solid fuels with CPWW ECC sludge showed its usefulness as a soil supplement and as an adsorbent for reutilization. The solid residue obtained after BECC was characterized using energy dispersive X-ray spectroscopy and other analyses. Summarizing the results, it was concluded that BECC can be effectively used for maximum removal of organics from raw CPWW with clean water reclamations of up to ∼90% using ECC as a novel treatment technique.

In vivo antioxidant activity of carotenoids from Dunaliella salina--a green microalga.

Dunaliella salina a green marine alga is known for its carotenoid accumulation, having various applications in the health and nutritional products. The purpose of present study was to evaluate the ability of D. salina algal powder extract to protect against oxidative stress In vivo using animal models. Treatment of albino Wistar strain rats with 125 microg/kg and 250 microg/kg b.w. showed significant protection when compared to toxin treated (CCl4) group. Since beta-carotene is major constituent of Dunaliella the results were also compared with group treated with 250 microg/kg b.w (p.o.) synthetic all trans beta-carotene. Treatment of CCl4 at dose of 2.0 g/kg b.w. decreased the activities of various antioxidant enzymes like catalase, superoxide dismutase (SOD) and peroxidase by 45.9%, 56% and 54% respectively compared to control group and lipid peroxidation value increased nearly 2 folds. Pretreatment of rats with 125 microg carotenoid followed by CCl4 treatment caused restoration of catalase, SOD and peroxidase by 25.24%, 23.75 and 61.15% respectively as compared to control. The group treated with 250 microg/kg has shown the restoration of 53.5%, 57.7 and 90.64% of catalase, SOD and peroxidase, respectively. This group has shown 75.0% restoration of peroxidation compared to control group of animals. The above enzyme activities were not significantly restored in group treated with synthetic all trans beta-carotene, which showed 7.5%, 23.8% restore in catalase and peroxidase content. The level of superoxide dismutase remained same and lipid peroxidation value decreased only by 23% in synthetic all trans beta-carotene treated group in comparison with control group. These results clearly indicate the beneficial effect of algal carotenoid compared to synthetic carotene as antioxidant. Owing to this property, the algae Dunaliella can be further extended to exploit, its possible application for various health benefits as nutraceuticals and food additive.

Antioxidant and antimicrobial activity of Cissus quadrangularis L.

Extracts of Cissus quadrangularis L. were tested for antioxidant activity by beta-carotene linoleic acid model and also by 1,1-diphenyl-2-picrylhydrazyl model. The ethyl acetate fraction of both fresh and dry stem extracts at a concentration of 100 ppm showed 64.8% antioxidant activity in the beta-carotene linoleic acid system and 61.6% in the 1,1-diphenyl-2-picrylhydrazyl system. This fraction showed the presence of sterols, vitamin C, and tannins as phytoconstituents. The antioxidant activity of methanol extract and aqueous extract were comparatively less significant than that of ethyl acetate extract, and n-hexane extract showed the least activity. The ethyl acetate extract and methanol extract of both fresh and dry stems further exhibited antimicrobial activity against Gram-positive bacteria, including Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, and Streptococcus species. The results of the study have implications in the use of C. quadrangularis as an antibacterial agent and more so as an antioxidant in several applications requiring these properties.