57 research outputs found
Performance evaluation of reverse osmosis (RO) pre-treatment technologies for in-land brackish water treatment
Integration of renewable energy with desalination technologies has emerged as an attractive solution to augment fresh water supply sustainably. Fouling and scaling are still considered as limiting factors in membrane desalination processes. For brackish water treatment, pre-treatment of reverse osmosis (RO) feed water is a key step in designing RO plants avoiding membrane fouling. This study aims to compare at pilot scale the rejection efficiency of RO membranes with multiple pre-treatment options at different water recoveries (30, 35, 40, 45 and 50%) and TDS concentrations (3500, 4000, and 4500mg/L). Synthetic brackish water was prepared and performance evaluation were carried out using brackish water reverse osmosis (BWRO) membranes (Filmtec LC-LE-4040 and Hydranautics CPA5-LD-4040) preceded by 5 and 1μm cartridge filters, 0.02μm ultra-filtration (UF) membrane, and forward osmosis (FO) membrane using 0.25M NaCl and MgCl2 as draw solutions (DS). It was revealed that FO membrane with 0.25M MgCl2 used as a draw solution (DS) and Ultra-filtration (UF) membrane followed by Filmtec membrane gave overall 98% rejection but UF facing high fouling potential due to high applied pressure. Use of 5 and 1μm cartridge filter prior to Filmtec membrane also showed effective results with 95% salt rejection
Factors influencing pigment production by halophilic bacteria and its effect on brine evaporation rates
The disposal of reject brine, a highly concentrated
waste by-product generated by various industrial
processes, represents a major economic and environmental
challenge. The common practice in dealing
with the large amounts of brine generated is to
dispose of it in a pond and allow it to evaporate. The
rate of evaporation is therefore a key factor in the
effectiveness of the management of these ponds.
The addition of various dyes has previously been
used as a method to increase the evaporation rate.
In this study, a biological approach, using pigmented
halophilic bacteria (as opposed to chemical dyes),
was assessed. Two bacteria, an Arthrobacter sp. and
a Planococcus sp. were selected due to their ability
to increase the evaporation of synthetic brine. When
using industrial brine, supplementation of the brine
with an iron source was required to maintain the pigment
production. Under these conditions, the
Planococcus sp. CP5-4 produced a carotenoid-like
pigment, which resulted in a 20% increase in the
evaporation rate of the brine. Thus, the pigment production
capability of halophilic bacteria could potentially
be exploited as an effective step in the
management of industrial reject brines, analogous to
the crystallizer ponds used to mine salt from sea
water
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