The removal of trivalent chromium from a combined tannery effluent in horizontal settling tanks and subsequent Advanced Integrated Wastewater Pond System (AIWPS) reactors was investigated. The raw combined effluent from Modjo tannery had pH in the range of 11.2-12. At this pH, a trivalent chromium removal of 46-72% was obtained in the horizontal settling tanks after a one-day detention time. Trivalent chromium precipitated as chromium hydroxide, Cr(OH)3. 58-95% Cr(III) was removed in the advanced facultative pond (AFP) where the water column pH of 7.2-8.4 was close to pH 8, which is the optimum precipitation pH for trivalent chromium. Chromium removals in the secondary facultative pond (SFP) and maturation pond (MP) were 30-50% and 6-16%, respectively. With Cr(III) concentration of 0.2-0.8 mg/l in the final treated effluent, the AIWPS preceded by horizontal settling tanks produced effluent that could easily meet most of the current Cr(III) discharge limits to receive water bodies.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.biortech.2005.04.028 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
A novel method to enhance the efficiency of aldehyde tanning agents via collagen amination.
Int J Biol Macromol
December 2024
Key Laboratory of Special Functional and Smart Polymer Materials of Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an 710129, China.
The utilization of chromium free tanning agents generates lots of pollutants such as chromium containing wastewater and sludge. Besides, trivalent chromium may be converted into carcinogenic hexavalent chromium under certain conditions, causing permanent harm to the human body. Therefore, the promotion of chromium free tanning technology is extremely significant.
View Article and Find Full Text PDFRare-Metal-Free Ultrabroadband Near-Infrared Phosphors.
Adv Mater
December 2024
College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027, China.
Trivalent chromium (Cr) is an attractive near-infrared (NIR) emitter, but its ultrabroadband NIR emission is limited to host crystals containing large amounts of rare-metal elements and usually suffers from low internal quantum efficiency (IQE) and poor thermal stability. Here, a class of high-performance, rare-metal-free ultrabroadband NIR phosphors, are reported by revealing that weak-field Cr centers featuring broadband NIR emission with near-unity IQEs are intrinsic, though in trace quantities, to Cr doped MgAlO spinel (MAS) and its derivatives well-known for their narrowband far-red emission. It is shown that such weak-field Cr centers stem from cation inversion ubiquitous in spinel compounds, and their quantity can be increased simply by superstoichiometric AlO/GaO.
View Article and Find Full Text PDFTrivalent Chromium Ameliorates Lipid Accumulation and Enhances Glucose Metabolism in the High-NEFA Environment of Bovine Hepatocytes by Regulating PI3K/AKT Pathways.
J Agric Food Chem
December 2024
College of Veterinary Medicine, Northwest A&F University, Yangling, Xianyang, Shaanxi 712100, China.
During the periparturient transition period, dairy cows are often accompanied by disorders of liver glycolipid metabolism. The PI3K/AKT signaling pathway plays an important role in the homeostasis of glycolipid metabolism. Trivalent chromium [Cr(III)] is an essential trace element in the body.
View Article and Find Full Text PDFChromium supplementation and type 2 diabetes mellitus: an extensive systematic review.
Environ Geochem Health
November 2024
Laboratory of Hydrogeology, Department of Geology, University of Patras, Rion, 26500, Patras, Greece.
Diabetes is a global public health concern with increasing prevalence worldwide. Chromium (Cr), a trace element found in soil, water, and food, has been proposed to have a possible positive effect in glucose metabolism and diabetes mellitus prevention. However, the relationship between trivalent chromium [Cr(III)] exposure, mainly through the consumption of diet supplements, and type 2 diabetes mellitus (T2DM) remains controversial.
View Article and Find Full Text PDFButterfly-Inspired Multiple Cross-Linked Dopamine-Metal-Phenol Bioprosthetic Valves with Enhanced Endothelialization and Anticalcification.
ACS Appl Mater Interfaces
November 2024
Department of Cardiovascular Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071, China.
Valve replacement is the most effective means of treating heart valve diseases, and transcatheter heart valve replacement (THVR) is the hottest field at present. However, the durability of the commercial bioprosthetic valves has always been the limiting factor restricting the development of interventional valve technology. The chronic inflammatory reaction, calcification, and difficulty in endothelialization after the implantation of a glutaraldehyde cross-linked porcine aortic valve or bovine pericardium often led to valve degeneration.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!