Palm oil mill effluent treatment and CO<Subscript>2</Subscript> sequestration by using microalgae—sustainable strategies for environmental protection

In this era of globalization, various products and technologies are being developed by the industries. While resources and energy are utilized from processes, wastes are being excreted through water streams, air, and ground. Without realizing it, environmental pollutions increase as the country develops. Effective technology is desired to create green factories that are able to overcome these issues. Wastewater is classified as the water coming from domestic or industrial sources. Wastewater treatment includes physical, chemical, and biological treatment processes. Aerobic and anaerobic processes are utilized in biological treatment approach. However, the current biological approaches emit greenhouse gases (GHGs), methane, and carbon dioxide that contribute to global warming. Microalgae can be the alternative to treating wastewater as it is able to consume nutrients from wastewater loading and fix CO₂ as it undergoes photosynthesis. The utilization of microalgae in the system will directly reduce GHG emissions with low operating cost within a short period of time. The aim of this review is to discuss the uses of native microalgae species in palm oil mill effluent (POME) and flue gas remediation. In addition, the discussion on the optimal microalgae cultivation parameter selection is included as this is significant for effective microalgae-based treatment operations.     

Are deep eutectic solvents benign or toxic?

In continuation of investigation for environmentally benign protocol for new solvents termed deep eutectic solvents (DESs), it is herein reported results concerning the toxicity and cytotoxicity of choline chloride (ChCl) based DESs with four hydrogen bond donors including glycerine, ethylene glycol, triethylene glycol and urea. The toxicity was investigated using two Gram positive bacteria Bacillus subtilis and Staphylococcus aureus, and two Gram negative bacteria Escherichia coli and Pseudomonas aeruginosa. The cytotoxicity effect was tested using the Artemia salina leach. It was found that there was no toxic effect for the tested DESs on all of the studied bacteria confirming their benign effects on these bacteria. Nevertheless, it was found that the cytotoxicity of DESs was much higher than their individual components (e.g. glycerine, ChCl) indicating that their toxicological behavior is different. For our best knowledge this is the first time that toxicity and cytotoxicity of DESs were studied. The toxicity and cytotoxicity of DESs varied depending on the structure of components. Careful usage of the terms non-toxicity and biodegradability must be considered. More investigation on this matter is required.     

Exposure of Brassica juncea (L) to arsenic species in hydroponic medium: comparative analysis in accumulation and biochemical and transcriptional alterations

Arsenic (As) contamination in the environment has attracted considerable attention worldwide. The objective of the present study was to see the comparative effect of As species As(III) and As(V) on accumulation, biochemical responses, and gene expression analysis in Brassica juncea var. Pusa Jaganath (PJn). Hydroponically grown 14-day-old seedlings of B. juncea were treated with different concentrations of As(III) and As(V). Accumulation of total As increased with increasing concentration of both As species and exposure time, mainly in roots. Reduction in seed germination, root–shoot length, chlorophyll, and protein content were observed with increasing concentration and exposure time of both As species, being more in As(III)-treated leaves. PJn variety showed that antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX)) and stress-related parameters (cysteine, proline, and malondialdehyde (MDA)) were stimulated and allows plant to tolerate both As species. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis in leaves showed significant changes in protein profile with more stringent effect with As(III) stress. Semiquantitative RT-PCR analysis showed regulation in expression of phytochelatin synthase (PCS), metallothionine-2 (MT-2), glutathione reductase (GR), and glutathione synthetase (GS) genes under both As(III) and As(V) stresses. Results suggested that accumulation and inhibition on physiological parameters differ according to the As species, while molecular and biochemical parameters showed a combinatorial type of tolerance mechanism against As(III) and As(V) stresses.     

Mercury contamination in the estuaries and coastal sediments of the Strait of Malacca

Fishers’ local ecological knowledge (LEK) is an additional tool to obtain information about cetaceans, regarding their local particularities, fishing interactions, and behavior. However, this knowledge could vary in depth of detail according to the level of interaction that fishers have with a specific species. This study investigated differences in small-scale fishers’ LEK regarding the estuarine dolphin (Sotalia guianensis) in three Brazilian northeast coastal communities where fishing is practiced in estuarine lagoons and/or coastal waters and where dolphin-watching tourism varies from incipient to important. The fishers (N?=?116) were asked about general characteristics of S. guianensis and their interactions with this dolphin during fishing activities. Compared to lagoon fishers, coastal fishers showed greater knowledge about the species but had more negative interactions with the dolphin during fishing activities. Coastal fishing not only offered the opportunity for fishers to observe a wider variety of the dolphin’s behavior, but also implied direct contact with the dolphins, as they are bycaught in coastal gillnets. Besides complementing information that could be used for the management of cetaceans, this study shows that the type of environment most used by fishers also affects the accuracy of the information they provide. When designing studies to gather information on species and/or populations with the support of fishers, special consideration should be given to local particularities such as gear and habitats used within the fishing community.     

Anthropogenic impacts on heavy metal concentrations in the coastal sediments of Dumai, Indonesia

Concentrations of Cd, Cu, Pb, Zn, Ni and Fe were determined in the surface sediments to investigate the distributions, concentrations and the pollution status of heavy metals in Dumai coastal waters. Sediment samples from 23 stations, representing 5 different site groups of eastern, central and western Dumai and southern and northern Rupat Island, were collected in May 2005. The results showed that heavy metal concentrations (in microg/g dry weight; Fe in %) were 0.88 (0.46-1.89); 6.08 (1.61-13.84); 32.34 (14.63-84.90); 53.89 (31.49-87.11); 11.48 (7.26-19.97) and 3.01 (2.10-3.92) for Cd, Cu, Pb, Zn, Ni and Fe, respectively. Generally, metal concentrations in the coastal sediments near Dumai city center (eastern and central Dumai) which have more anthropogenic activities were higher than those at other stations. Average concentration of Cd in the eastern Dumai was slightly higher than effective range low (ERL) but still below effective range medium (ERM) value established by Long et al. (Environmental Management 19(1):81-97, 1995; Environmental Toxicology Chemistry 17(4):714-727, 1997). All other metals were still below ERL and ERM. Calculated enrichment factor (EF), especially for Cd and Pb, and the Pollution load index (PLI) value in the eastern Dumai were also higher than other sites. Cd showed higher EF when compared to other metals. Geo-accumulation indices (I(geo)) in most of the stations (all site groups) were categorized as class 1 (unpolluted to moderately polluted environment) and only Cd in Cargo Port was in class 2 (moderately polluted). Heavy metal concentrations found in the present study were comparable to other regions of the world and based on the calculated indices it can be classified as unpolluted to moderately polluted coastal environment.     

Accumulation of endocrine disrupting chemicals (EDCs) in the polychaete Paraprionospio sp. from the Yodo River mouth,Osaka Bay,Japan

This study presents the levels of endocrine disrupting chemicals (EDCs) accumulated by Paraprionospio sp. from the Yodo River mouth, Osaka Bay. Since high concentrations of nonylphenol (NP), bisphenol A (BP), octylphenol (OP), 17β-estradiol (E2), and estrone (E1) have been measured in sediment from Osaka Bay, some bioaccumulation could be expected particularly in benthic animals. EDCs were analysed in Paraprionospio sp., a dominant benthic species in Osaka Bay. The results showed that Paraprionospio sp. had accumulated varying concentrations (wet weight; w.w.) of NP at 1,460–4,410 ng/g; BP at 22.5–39.6 ng/g; OP at 18.9–45.4 ng/g; E2 at 0.89–4.35 ng/g; and E1 at 0.06–2.50 ng/g. Accumulation of NP and OP were highest among the samples gathered in summer (July 2008), while concentrations of BP, E2, and E1 did not much differs within 3 years. EDC levels in Paraprionospio sp. were apparently greater than those in sediments showing bioaccumulation.     

Leachate characterization in semi-aerobic and anaerobic sanitary landfills: A comparative study

This study analyzes and compares the results of leachate composition at the semi-aerobic Pulau Burung Landfill Site (PBLS) (unaerated pond and intermittently aerated pond) and the anaerobic Kulim Sanitary Landfill in the northern region of Malaysia. The raw samples were collected and analyzed for twenty parameters. The average values of the parameters such as phenols (1.2, 6.7, and 2.6 mg/L), total nitrogen (448, 1200, and 300 mg/L N-TN), ammonia-N (542, 1568, and 538 mg/L NH₃-N), nitrite (91, 49, and 52 mg/L NO₂^?-N), total phosphorus (21, 17, and 19 mg/L), BOD₅ (83, 243, and 326 mg/L), COD (935, 2345, and 1892 mg/L), BOD₅/COD (0.096,0.1124,0.205%), pH (8.20, 8.28, and 7.76), turbidity (1546, 180, and 1936 Formazin attenuation units (FAU)), and color (3334, 3347, and 4041 Pt Co) for leachate at the semi-aerobic PBLS (unaerated and intermittently aerated) and the anaerobic Kulim Sanitary Landfill were recorded, respectively. The obtained results were compared with previously published data and data from the Malaysia Environmental Quality Act 1974. The results indicated that Pulau Burung leachate was more stabilized compared with Kulim leachate. Furthermore, the aeration process in PBLS has a considerable effect on reducing the concentration of several pollutants. The studied leachate requires treatment to minimize the pollutants to an acceptable level prior to discharge into water courses.