The electroplating industry generates wastewater containing a variety of heavy metals which potentially contaminate water ecosystems. The available and well-known electroplating wastewater treatments are considered as an expensive and less effective method, therefore phytoremediation was used as an alternative friendly solution. This study aims to evaluate the uptake and elimination rate of heavy metals by vetiver (Chrysopogon zizanoides L.) on metal-polluted water. Vetiver was planted in artificial electroplating wastewater containing different levels (low, medium, high) of chromium (Cr) and nickel (Ni). Water, roots, and shoots were collected periodically to determine Cr and Ni contents using Atomic Absorption Spectrometry (AAS). Metal accumulation and elimination rate, Bioconcentration Factor (BCF), Biological Absorption Coefficient (BAC), and Translocation Factor (TF) were calculated to evaluate plant’s effectiveness in metal remediation processes. The results showed that vetiver (C. zizanoides L.) was able to remove 61.10% Cr and 95.65% Ni on metal-contaminated water. The highest uptake rates for Cr and Ni are 127.21 mg/kg/day and 15.60 mg/kg/day respectively, while the elimination rates for Cr and Ni tend to slow 1.09 mg/kg/day and 12.24 mg/kg/day respectively. Vetiver BCF, BAC, and TF values on Cr and Ni contaminated water were greater than 1, which indicates that vetiver work through phytoextraction and phytostabilization to treat metals. The findings showed that vetiver has promise as a phytoremediation agent thus providing implication for electroplating wastewater treatment.

Wastewater from tofu (soybean curd) production contains a high organic concentration that might pollute the environment if it is not treated properly. Among the major organic constituents of tofu wastewater are proteins. Degradation of proteins generates ammonia and H2S gases, and if this occurs in an anaerobic digester might hamper the digester’s performance. On the other hand, proteins can potentially be recovered as value-added products. This research aimed to identify protein amounts in different fractions of tofu wastewater, as a basis of designing a process to recover the proteins. Furthermore, the influence of a lower protein concentration to anaerobic digestion of tofu wastewater was calculated. Tofu wastewater was fractionated by gravity settlement and filtration into settleable, suspended, and dissolved fractions. Subsequently, total solids, protein, and COD concentrations of each fraction were analysed. Our results show that tofu wastewater contained 2.9 g-protein/L, equivalent to 4 g-COD/L. While most of the proteins were dissolved, 9% of the proteins were settleable. This might be recovered via a settling chamber. Using the protein-separated wastewater in anaerobic digestion might reduce NH3 and H2S by 10% while only reduce biogas production by 2%.

The electroplating industry is one of the industries producing various kinds of pollutant waste. One of the pollutants is Copper (Cu). It can cause environmental problems such as soil pollution that endanger microorganisms and other living beings and shift its ecological balance. Phytoremediation is a way to improve polluted land by using plants. This study aimed to investigate the reduction of Cu after the treatment of vetiver (Chrysopogon zizanioides (L.) Roberty). Plants were grown on contaminated soil for 28 days (absorption condition), then transferred to the soil without contamination and allowed to live for 28 days (elimination condition). In this study, the concentration of Cu heavy metal was analyzed in plants using Atomic Absorption Spectrophotometer (AAS). Phytoremediation potential was evaluated through absorption rate, elimination rate, along with Bioconcentration Factor (BCF), Biological Absorption Coefficient (BAC), and Translocation Factor (TF). The results showed that C. zizanioides could absorb Cu with the highest absorption rate of 1.45 mg.kg−1.d−1 and the highest elimination rate of 0.36 mg.kg−1.d−1. The absorption rate tends to be higher than the elimination rate. In this case, C. zizanioides can be used as an alternative for phytoremediation of Cu contaminated soil in the lightly to heavily polluted category.