Fish Farm Wastewater Treatment using Moringa oleifera Seed Powder as Natural Coagulant

In view of the huge amount of wastewater being generated from the aquaculture sector in Malaysia, Moringa oleifera seed powder was utilized as effective bio-coagulant to minimize the deterioration of fish farm wastewater quality. In this study, optimization of a coagulation-flocculation process was examined through response surface model toolkit established on a central composite design. A quadratic polynomial model was eventually selected to fit its turbidity removal response. The effect of four crucial parameters, namely pH, coagulant dosage, mixing time and settling time was optimized at pH 10, 400 mg/L coagulant dosage, 15 minutes mixing time and 10 minutes settling time for M. oleifera seed extract at a 47.11% turbidity removal efficiency. M. oleifera seed powder substantially removed (>30%) the concentration of total suspended solids, ammonia content, total volatile solids, and phosphate content as compared with the control group without any coagulant addition.

Phycoremediation of fish farm wastewater by Chlorella sorokiniana and autochthonous microalgae

With the disorderly increase in global environmental problems, the cultivation of aquatic organisms is a promising path for sustainable food production. The quality of water, both at the entrance and exit of the production of aquatic animals, needs to be maintained following the parameters specified by local legislation. This study aimed to investigate the removal of contaminants from fish farming wastewater associated with the production of freshwater microalgae biomass. Six completely randomized treatments were used in triplicate: with the addition of microalgae C. sorokiniana in fish farm wastewater (W+Cs), the addition of C. sorokiniana in wastewater enriched with NPK fertilizing (W+F+Cs) or sugarcane vinasse (W+V+Cs), only wastewater (W), wastewater supplemented with fertilizer (W+F) or vinasse (W+V). The wastewater was used in natura to allow the development of autochthonous microalgae. The microalgae C. sorokiniana grew rapidly in effluents enriched with NPK and vinasse. After 28 days of bioassay, the concentrations of several contaminants in the water were reduced: zinc (20 to 88%), lead (5 to 83%), aluminum (56 to 75%), manganese (56 to 72%), cadmium (9 to 52%), calcium (16 to 24%) and magnesium (12 to 33%). Our results indicated that the production of microalgae biomass can be integrated with the treatment of fish farming effluents to reduce the environmental burden and increase the economic bonus for adopting a sustainable production method. However, our results also indicated the importance of introducing a microalgae strain with high productive performance and supplementing the wastewater to obtain rapid biomass.

Prevalence of extended-spectrum beta-lactamase-producing Escherichia coli strains in dairy farm wastewater in Chiang Mai

We investigated the prevalence of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli strains in dairy farm wastewater in Chiang Mai, Thailand. We analyzed wastewater samples collected from 150 dairy farms and found that 88.7% of the farms (n = 133) were positive for ESBL-producing E. coli. Multiplex polymerase chain reaction (PCR) amplification was performed to characterize the presence of bla CTX-M, bla TEM, and blaSHV in ESBL-producing isolates. blaCTX-M was found in all isolates (n = 133), followed by blaTEM (80/133, 60.2%), whereas blaSHV was not detected in any isolate. blaCTX-M and blaTEM were present in 60.2% (80/133) of the isolates, and 39.8% (53/133) isolates carried bla CTX-M alone. Subgroup analysis showed that CTX-M-1 was the most prevalent subgroup among the isolates (129/133, 97.0%), followed by CTX-M-8 (2/133, 1.5%) and CTX-M-9 (2/133, 1.5%). The distribution of the phylogenetic groups was as follows: group A (100/133, 75.2%), followed by B1 (14/133, 10.5%), D (6/133, 4.5%), F (6/133, 4.5%), B2 (4/133, 3.0%), and E (3/133, 2.3%). Based on enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) and dendrogram analysis, 24 isolates were classified into clades I (n = 21), II (n =1), and III (n =2). Minor genetic differences were found in all clade I isolates. Our data suggest that the circulating of ESBL-producing E. coli carried at least one bla gene strain distributed in dairy farm wastewater in Chiang Mai.