Experimental Study for Sand Filter Backwash Water Management: Low-Cost Treatment for Recycling and Residual Sludge Utilization for Radium Removal

Management of backwash water (BW) generated from sand filtration of groundwater naturally contaminated with iron (Fe), manganese (Mn), and radium (Ra) remains a challenge worldwide. The present study investigated the effectiveness of a low-cost clay ceramic filter for BW recycling along with residual sludge utilization for Ra removal from BW. A 15 day continuous ceramic filtration process operated at a constant flux of 2000 L/m2/d (83 LMH) showed 99% removal of Fe, Mn, and turbidity. The treated BW was found suitable for recycling back to the sand filters. Subsequently, the residual sand filter backwash sludge (BS) was collected, characterized by scanning electron microscopy (SEM) and X-ray diffraction, and examined as a potential adsorbent to the Ra. Results showed that the sludge constituted heterogeneous basic elements, with higher percentages of iron and manganese oxides. The sludge can be classified as typical mesoporous and poorly crystalline minerals consisting primarily of quartz and Mn2O3. Over 60% of Ra from the initial 2.1 bq/L could be removed by sludge in 30 min at neutral pH. The adsorption kinetics of sludge described well by the pseudo-second order model and Ra adsorption on the sludge were mainly controlled by chemisorption rate-controlling steps, intraparticle diffusion, and external mass transfer processes. Treatment of BW by low-cost clay ceramic filters and the utilization the BS for Ra removal would be a sustainable sand filter BW management practice.

DEVELOPMENT OF CONTINUOUS ANTI-SOLVENT RECRYSTALLIZATION METHOD TO PRODUCE CEFTRIAXONE SODIUM NANO CRYSTALS INJECTION USING CERAMIC FILTRATION

The aim: In this work we developed a method of continuous recrystallization to meet industrial requirements. Materials and methods: Continuous recrystallization method was investigated using porous ceramic filter for water purification with pour size less than 1 μm, that ensures high mixing rate of ethanol and water. Results and conclusions: The results of experiments using crystallization through ceramic filter, gives superior products in particle size, and produced needle shaped ceftriaxone crystals form, that showed significant improvement in dissolution time and obtained ceftriaxone sodium powder to be reconstituted in injectable formula that give clear solution without insoluble microparticles.

Evaluation of a Low-Cost Ceramic Filter for Sustainable Reuse of Urban Stormwater in Arid Environments

Sustainable reuse of urban stormwater is inevitable in the fight against water crises in arid regions. This research aimed to evaluate the effectiveness of a low-cost ceramic filtration process for reuse applications of urban stormwater. Stormwater was collected from a storage pond located in Buraydah (Qassim, Saudi Arabia) for laboratory experiments. The filtration tests were performed in a continuous mode with constant pressure using a low-cost ceramic filter made of clay soil and rice bran. The removal rates of the contaminants (heavy metals) as well as the turbidity, suspended solids, and nutrients of the stormwater were assessed. High removal efficiencies for turbidity (97.4%), suspended solids (97.0%), BOD5 (78.4%), and COD (76.1%) were achieved while low removals were achieved for the nutrients: 19.7% for total nitrogen, 25.3% for nitrate, and 8.6% for phosphate. Removal efficiencies ranged between 36.2% and 99.9% for the heavy metals, i.e., iron, manganese, lead, zinc, nickel, copper, cadmium, selenium, and barium. Contaminant removal rates observed for the ceramic filter were also compared with the alum coagulation process operated in a continuous mode at an optimum alum dose of 50 mg/L. Similar removal behaviors for removal of turbidity, suspended solids, organics, nutrients, and heavy metals suggested that both ceramic filtration and alum coagulation can be effectively used for stormwater treatment. Effluent qualities of both the ceramic filter and alum coagulation met the standards, for recycling/reuse of wastewater, set by the Kingdom of Saudi Arabia and World Health Organization for unrestricted irrigation and toilet flushing. The study results revealed that ceramic filtration is a low-cost, energy efficient, and easy to maintain technology which can be complimentary to best management practices for stormwater.

Benefits of polymeric membranes in Oil and Gas produced water treatment

Falling oil prices and increased environmental concern lead oil and gas companies to reinject produced water(PW) to reduce both their water management costs and environmental footprint. Membrane processes are an attractive opportunity because they generate a higher quality effluent than conventional PW treatment technologies at a competitive cost. The objective of the study was to compare the performances of ten membranes to treat PW and identify which of the structural and operational characteristics of the membranes are the success factors to ensure cost-effective, long-term and reliable operation. In oil and gas applications, ceramic filtration media is often preferred owing to its high structural robustness. Nevertheless, polymeric membranes offer the benefits of being less expensive and result in a lower footprint and weight. Tests using real oilfield PW were run to assess and compare ten membranes according to their oil rejection rate, permeability, resistance to fouling, life expectancy and resistance to ageing. All membranes tested achieved more than 99% removal of insoluble oil versus 80–85% for conventional technologies. The permeability over time and resistance to fouling were used to identify the most reliable and cost-effective membranes. The robustness of polymeric membranes was confirmed based on good resistance to ageing.

Research and Development of Ceramic Filtration Membrane

Ceramic filter membrane plays an irreplaceable role in many fields because of its unique advantages. However, the complicated preparation process and high cost still limit the large scale application of ceramic filter membrane. Therefore, to improve the preparation process of ceramic filter membrane, optimize the membrane system structure is the ceramic filter membrane industry is facing major problems. In this paper, the structure, separation principle, preparation technology and application of ceramic filter membrane are introduced.