Hexavalent chromium sequestration from electronic waste by biomass of .

The idea of eliminating noxious metal ions from electronic waste contaminated water has led to the use of the metal adsorbing ability of biological matter. The principle of an ion exchanger of biological origin is the key in exhibiting this metal binding feature of microbial biomass. In this study, dead biomass of was immobilized using sodium alginate and tested as a biosorbent for hexavalent chromium elimination from effluent.

Recent developments and prospects of dioxins and furans remediation.

Rapid urbanization and industrialization of anthropogenic activities have exerted immense pressure on the environment. Polyhalogenated organic compounds, especially dioxins and furans are regarded as ubiquitously persistent environmental pollutants in the ecosystem. The recalcitrant nature of dioxins and furans induce toxicity in both humans and wildlife.

Biosorption of chromium(VI) in aqueous solutions by chemically modified Strychnine tree fruit shell.

Chromium(VI) was removed from aqueous solution using sulfuric- and phosphoric-acid-activated Strychnine tree fruit shells (SSTFS and PSTFS) as biosorbents. Effects of various parameters such as adsorbent dose (0.02-0.

Adsorption of hexavalent chromium from synthetic and electroplating effluent on chemically modified Swietenia mahagoni shell in a packed bed column.

Packed bed column studies were carried out to evaluate the performance of chemically modified adsorbents for the sequestration of hexavalent chromium from synthetic and electroplating industrial effluent. The effects of parameters such as bed height (3-9 cm), inlet flow rate (5-15 mL/min), and influent Cr(VI) concentration (50-200 mg/L) on the percentage removal of Cr(VI) and the adsorption capacity of the adsorbents in a packed bed column were investigated. The breakthrough time increased with increasing bed height and decreased with the increase of inlet flow rate and influent Cr(VI) concentration.

Hexavalent chromium removal from aqueous solutions by a novel powder prepared from Colocasia esculenta leaves.

In this study, batch removal of hexavalent chromium from aqueous solutions by powdered Colocasia esculenta leaves was investigated. Batch experiments were conducted to study the effects of adsorption of Cr(VI) at different pH values, initial concentrations, agitation speeds, temperatures, and contact times. The biosorbent was characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectrometer analysis.

Potential application of pectinase in developing functional foods.

The understanding that enzymatic degradation of fruit pectin can clarify juices and improve juice yields resulted in the search for microbial pectinases and application in vegetable- and fruit-processing industries. Identified enzymes were classified on the basis of their catalytic activity to pectin or its derivatives and in terms of industrial use. Discovery of gene sequences that coded the enzymes, protein engineering, and molecular biology tools resulted in defined microbial strains that over-produced the enzymes for cost-effective technologies.

Techno-economic analysis of processes for Aspergillus carbonarius polygalacturonase production.

A techno-economic analysis of submerged (SmF) and solid state fermentation (SSF) processes for Aspergillus carbonarius polygalacturonase production was performed to make an appropriate process selection. The downstream processing involved integrated membrane process (IMP) and alginate affinity precipitation (AAP). For a production scale of 30kL purified polygalacturonase concentrate per year, the total upstream cost of SmF was 14% lower than the SSF process.

Aspergillus carbonarius polygalacturonases purified by integrated membrane process and affinity precipitation for apple juice production.

Aspergillus carbonarius, when grown by submerged and solid-state fermentation, produces different molecular forms of polygalacturonase (PG; EC 3.2.1.

Extraction, purification and concentration of partially saturated canthaxanthin from Aspergillus carbonarius.

A mutant Aspergillus carbonarius produces partially saturated canthaxanthin (PSC; C(40)H(62)O(2)) during submerged fermentation. The pigment was extracted from dried biomass using various organic solvents and purified using nanofiltration (NF) and nonporous membranes. Particle size had a great influence; PSC extractability from fines fraction of biomass (75-105 microm) was 1.

Purification of polygalacturonase from solid-state cultures of Aspergillus carbonarius.

Purification of polygalacturonase (PG) from the cultures of Aspergillus carbonarius obtained by acetate buffer extraction after solid-state fermentation was attempted by integrated membrane process and alginate affinity precipitation. The carbohydrates were completely eliminated (98%-99%) with a PG recovery of 72%-80% during integrated membrane process, which would otherwise interfere with the purification process and lead to enzyme loss. However, specific activity of PG did not improve (1.

Improving specific activity of Aspergillus carbonarius polygalacturonase using polymeric membranes.

Microfiltration (MF) and ultrafiltration (UF) membranes were screened for improving the specific activity of polygalacturonases (PG) in the culture broth of Aspergillus carbonarius obtained after submerged fermentation. While 200 and 450 nm MF membranes eliminated some of the larger non-enzymatic proteins, 50 kDa UF membrane exhibited a marginal selectivity between the enzyme and other smaller proteins. The 450 nm MF and 50 kDa UF membranes selected were further evaluated under different process conditions for an integrated membrane process.