Over the past three decades, chemical and biological water contamination has become a major concern, particularly in the industrialized world. Heavy metals, aromatic compounds, and dyes are among the harmful substances that contribute to water pollution, which jeopardies the human health. For this reason, it is of the utmost importance to locate methods for the cleanup of wastewater that are not genuinely effective. Owing to its non-toxicity, biodegradability, and biocompatibility, starch is a naturally occurring polysaccharide that scientists are looking into as a possible environmentally friendly material for sustainable water remediation. Starch could exhibit significant adsorption capabilities towards pollutants with the substitution of amide, amino, carboxyl, and other functional groups for hydroxyl groups. Starch derivatives may effectively remove contaminants such as oil, organic solvents, pesticides, heavy metals, dyes, and pharmaceutical pollutants by employing adsorption techniques at a rate greater than 90%. The maximal adsorption capacities of starch-based adsorbents for oil and organic solvents, pesticides, heavy metal ions, dyes, and pharmaceuticals are 13,000, 66, 2000, 25,000, and 782 mg/g, respectively. Although starch-based adsorbents have demonstrated a promising future for environmental wastewater treatment, additional research is required to optimize the technique before the starch-based adsorbent can be used in large-scale in situ wastewater treatment.

Copper is one of the chemical elements that is widely used in various sectors nowadays together with the development of civilization especially in agricultural and industrial sectors. Copper is also considered as one of the heavy metals that is commonly present in wastewater. This preliminary study conducted is mainly focused on the techniques of removal of copper in wastewater. There are a variety of approaches for treating industrial effluent contaminated with heavy metals such as copper. Copper separation can be accomplished using a variety of technologies, each of which has advantages that vary depending on the application. Chemical removal techniques that are commonly used for copper removal are adsorption, cementation, membrane filtration, electrochemical method, and photocatalysis. This study compares the fundamentals and performances of the treatment techniques in addition to the future perspective of copper removal in detail. The study highlights the present research in terms of its strengths and shortcomings, pointing out deficiencies that need to be addressed in future studies, pointing to future research prospects.

As a novel filtration process driven by osmotic pressure, forward osmosis (FO) filtration process offers low fouling propensity and is a potential solution to energy generation and resource recovery from wastewater via direct filtration enriching pollutants into small volume of concentrate. In this study, the characteristics of fouling formation on cellulose triacetate (CTA) FO membranes were investigated using direct filtering of raw domestic wastewater in a FO process. The cleaning efficiency of three environmentally friendly reagents (i) reverse osmosis (RO) water, (ii) ethanol (70 w/w%) and (iii) free nitrous acid (FNA) (35 mg HNO₂–N per L), in fouling control and membrane stability was evaluated through flux and selectivity measurements. From ten successive cleaning cycles, the efficiency of these cleaning reagents in the membrane flux recovery follows the order of ethanol (8.01 ± 0.31 L m⁻² h⁻¹ (LMH)) > FNA (5.83 ± 0.36 LMH) > RO water (3.55 ± 0.29 LMH) > control (2.09 ± 0.28 LMH). Although ethanol completely recovered the water flux performance and inactivated the biomass from the fouling layer, it appeared to have compromised the membrane integrity, which was demonstrated by an increased apparent reverse salt flux. After 1 hour of cleaning with ethanol, the apparent reverse salt flux dramatically increased to between 12.58 g m⁻² h⁻¹ and 47.21 g m⁻² h⁻¹. The FNA did not show any sign of deteriorating the CTA membrane integrity, however, 94% inactivation of bacteria required 8 hours of exposure time. These results indicate that FNA shows good potential to be used as a cleaning reagent in FO processes for membrane fouling control. Further studies are still needed to improve the efficiency of FNA dosing and required exposure time.

The application of forward osmosis (FO) membrane-based technology in urban wastewater treatment has received increased attention, however, its techno-economic feasibility and sustainability have not been fully demonstrated. In this study, the feasibility of FO application in urban wastewater treatment was assessed in terms of economic performance, energy consumption and greenhouse gas (GHG) emissions benchmarked against microfiltration (MF). Three different scenarios of wastewater treatment and water reclamation were proposed: (A) forward osmosis aerobic membrane bioreactor (FOAeMBR); (B) FOAeMBR integrated with reverse osmosis (RO); (C) forward osmosis anaerobic membrane bioreactor (FOAnMBR) integrated with partial nitrification/anammox (PN/AMOX) process. In this study, the wastewater treatment and reclamation costs by using FO in scenarios A and B were more expensive than MF by $0.16 per m³ and $0.75 per m³ respectively due to the larger surface area of FO membrane required. In scenario C, the wastewater treatment cost of using FO ($1.11 per m³) was equivalent to MF. This was due to the good rejection performance of FO and its ability to concentrate wastewater, hence, resulting in a higher efficiency of (PN/AMOX) in comparison to MF. In addition, the application of FO in scenario C generated total GHG emissions to be as low as 0.93 kg CO₂ equivalent m⁻³, which was 1.5 and 4.1 times lower than scenarios A and B respectively. The minimal net energy consumption and low carbon footprint of FO application in scenario C suggests this integration will likely be a feasible membrane-based technology for the next generation of wastewater treatment.