Combined adsorbents and reactive oxygen species (ROS) generators in soil for treating reverse osmosis concentrates

Comparative assessment of treatment technologies for minimizing reverse osmosis concentrate volume for industrial applications: A review

Desalination of seawater, brackish water, and reclaimed water is becoming increasingly prevalent worldwide to supplement and diversify fresh water supplies. However, particularly for industrial wastewater, the need for environment-friendly and economically viable alternatives for concentrate management is the major impediment to deploying large-scale desalination. This review covers various strategies and technologies for managing reverse osmosis concentrate (ROC) and also includes their disposal, treatment, and potential applications. Developing energy-efficient, economical, and ecologically sound ROC management systems is essential if desalination and wastewater treatment are being implemented for a sustainable water future, particularly for industrial wastewater. The limitations and benefits of various concentrate management strategies are examined in this review. Moreover, it explores the potential of innovative technologies in reducing concentrate volume, enhancing water recovery, eliminating organic pollutants, and extracting valuable resources. This review critically discusses concentrate management approaches and technologies, including disposal, treatment, and reuse, including new technologies for reducing concentrate volume, boosting water recovery, eliminating organic contaminants, recovering valuable commodities, and minimizing energy consumption.

Treatment of reverse osmosis (RO) concentrate by the combined Fe/Cu/air and Fenton process (1stFe/Cu/air-Fenton-2ndFe/Cu/air)

To decompose or transform the toxic and refractory reverse osmosis (RO) concentrate and improve the biodegradability, 1stFe/Cu/air-Fenton-2ndFe/Cu/air were developed to treat RO concentrate obtained from an amino acid production plant in northern China. First, their operating conditions were optimized thoroughly. Furthermore, 5 control experiments were setup to confirm the superiority of 1stFe/Cu/air-Fenton-2ndFe/Cu/air and synergistic reaction between Fe/Cu/air and Fenton. The results suggest that the developed method could obtain high COD removal (65.1%) and BOD5/COD ratio (0.26) due to the synergistic reaction between Fe/Cu/air and Fenton. Under the optimal conditions, the influent and effluent of 1stFe/Cu/air-Fenton-2ndFe/Cu/air and 5 control experiments were analyzed by using UV, FTIR, EEM and LC, which confirm the superiority of 1stFe/Cu/air-Fenton-2ndFe/Cu/air. Therefore, the developed method in this study is a promising process for treatment of RO concentrate.

Contaminants of emerging concern in reverse osmosis brine concentrate from indirect/direct water reuse applications

Water shortage is becoming more common due to droughts and global population increases resulting in the increasing popularity of water reuse to create new water sources. Reverse osmosis (RO) membrane systems are popular in these applications since they can produce drinking water quality effluent. Unfortunately, RO systems have the drawback of generating concentrate streams that contain contaminants rejected by the membrane including chemicals of emerging concern (CECs). CECs are chemicals such as hormones, steroids, pesticides, pharmaceuticals, and personal care products that are used for their intended purpose and then released into wastewater. CECs are believed to be detrimental to aquatic wildlife health and pose an unknown human health risk. This research gathered the existing knowledge on CEC presence in concentrate, available proven concentrate treatment methods, their CEC removal abilities, and current CEC regulations. It was found that 127 CECs have been measured in RO concentrate with 100 being detected at least once. The most potent treatment process available is UV/H2O2 as it offers the highest removal rates for the widest range of chemicals. The less expensive process of ozone/biologically activated carbon offers slightly lower removal abilities. This comprehensive report will provide the groundwork for better understanding, regulating and treating concentrate stream CECs.

Novel technologies for reverse osmosis concentrate treatment: a review

Global water shortages due to droughts and population growth have created increasing interest in water reuse and recycling and, concomitantly, development of effective water treatment processes. Pressured membrane processes, in particular reverse osmosis, have been adopted in water treatment industries and utilities despite the relatively high operational cost and energy consumption. However, emerging contaminants are present in reverse osmosis concentrate in higher concentrations than in the feed water, and have created challenges for treatment of the concentrate. Further, standards and guidelines for assessment and treatment of newly identified contaminants are currently lacking. Research is needed regarding the treatment and disposal of emerging contaminants of concern in reverse osmosis concentrate, in order to develop cost-effective methods for minimizing potential impacts on public health and the environment. This paper reviews treatment options for concentrate from membrane processes. Barriers to emerging treatment options are discussed and novel treatment processes are evaluated based on a literature review.

Occurrence of emerging and priority pollutants in municipal reverse osmosis concentrates

This paper aimed to investigate the occurrence and concentrations of emerging and priority pollutants in the municipal reverse osmosis concentrate (ROC) using liquid-liquid extraction (LLE) followed by gas chromatography-mass spectrometry. The results indicated that there were varieties of pollutants, including chlorinated organic compounds, polycyclic aromatic hydrocarbons (PAHs), phthalate esters (PAEs), pharmaceutical and personal care products (PPCPs), herbicides and flame retardants, in the ROC. Most of the pollutants were quantified, and the performance of the analytical method was explored. For most of the target compounds, the mean recoveries at two concentration levels (0.17 μg L(-1) and 1.67 μg L(-1)) ranged from 70% to 130% and the relative standard deviation (RSD) values were less than 20%, indicating excellent accuracy and precision. Typical concentrations of most of the pollutants were as low as tens or hundreds of ng L(-1), whereas others were as high as several μg L(-1) (such as, the concentration of 2-chloroethyl ether was 1.42 μg L(-1), of caffeine was 3.73 μg L(-1), and of benzyl butyl phthalate was 4.90 μg L(-1)).